I learn and enjoy the project in Bhilai steel plant. It is very important part of Blast Furnace of a steel industry. Mudgun and mudgun column repaired in MARS2 repairing workshop in Bhilai Steel Plant.

1. P a g e | 1
DATE 11/12/17- 06/01/18
PROJECT REPORT ON PREPARATION OF
HYDRAULIC MUDGUN COLUMN ASSEMBLY
OF BLAST FURNACE IN MARS-2.
Submitted by
ABUZAR, Roll No. : P-17 / 7128
BASANT SAHU, Roll No. : P-17 / 7129
ABDUL ALI ADIL KHAN, Roll No. : P-17 / 7130
DHALENDRA SAHU, Roll No. : P-17 / 7131
AVINASH DEWANGAN, Roll No. : P-17 / 7132
AMIT KUMAR PANDAY, Roll No. : P-17 / 7133
Under the Guidance of
1. Mr. GITESH DEWANGAN
Deputy MGR. (MARS-2), BSP, Bhilai
2. Mr. RAVINDRA KUMAR
Sr. Technician (MARS-2), BSP, Bhilai

2. P a g e | 2
Contents
INTRODUCTION
 Introduction to Bhilai Steel Plant
1. CHAPTER 1: A REPORT ON MARS-2
1.1 Introduction to MARS-2
1.2 Annual Production in MARS-2
1.3 Cost Control of MARS-2 during 2015-16
2. CHAPTER 2 : BLAST FURNACE
2.1 Introduction
2.2 Blast furnace constructional features
2.3 Blast furnace processes
2.4 Reactions in Blast furnace
2.5 The Facilities at B.S.P
3. CHAPTER 3: A BRIEF DISCUSSION ON MUDGUN ASSEMBLY
3.1 Introduction
3.2 Location of MUDGUN assembly.
3.3 Different parts present in Mudgun assembly.
4. CHAPTER 4: PREPARATION OF MUDGUN ASSEMBLY
4.1 Introduction
4.2 Description of the process
4.3 Various instruments used in the reassembling process
5. CHAPTER 5:FAILURES IN MUDGUN ASSEMBLY AND MEASURES FOR PREVENTION
5.1 Introduction
5.2 Failures in bearings - causes and cures
5.3 Failures in Hydraulic cylinder - causes and cures
6. CONCLUSION
7. REFERENCES

3. P a g e | 3
ACKNOWLEDGEMENT
We deem it a privilege to have been the student of Mechanical Engineering
stream. Our heart feel thanks to safety training and development center of
Bhilai steel plant for giving an opportunity to do the summer internship.
Our sincere regards to Mr. S.R. Sinha for helping us realize the do’s and don’ts
pertaining to this specific project and helping us in all other sort of ways
throughoutthe entire duration of our projectwork.
Our heartfelt thanks to Mr. Gitesh Dewangan, Deputy Manager (MARS-2),
Bhilai Steel Plant our project guide who helped us to bring out this project in
good manner with his precious suggestions and rich experience. We take this
opportunity to express our sincere thanks to our project guide for cooperation
in accomplishing this project a satisfactory conclusion.
We would also like to pay our sincere gratitude to Deputy General
Manager (M.A.R.S.2) for further clarifying our doubts, with their year long
experience that we came to know how practical field work is done in the
industry, which one can’tfind in the books.
We must put in writing our thanks to Mr. Ravindra Kumar, Sr. Technician
(MARS-2), who has given valuable suggestions guidance our project topic and
also thanks to all of the MARS-2 employees who helped us while visiting the
plant. Our sincere thanks to all those who directly or indirectly helped for
completion of this project.

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AN INTRODUCTION TO BHILAI STEEL PLANT
Bhilai Steel Plant - a symbol of Indo-Soviet techno-economic collaboration is one of the first
three integrated steel plants set up by Government of India to build up a sound base for the
industrial growth of the country, The agreement for setting up the plant with a capacity of 1
MT of Ingot steel was signed between the Government of erstwhile U.S.S.R. and India on
2nd February, 1955, and only after a short period of 4 years, India entered the main stream
of the steel producers with the commissioning of its first Blast Furnace on 4th February, 1959
by the then President of India, Dr. Rajendra Prasad. Commissioning of all the units of 1 MT
stage was completed in 1961. A dream came true-the massive rocks from the virgin terrains
of Rajhara were converted into valuable iron & steel.
In the initial phase the plant had to face many teething problems, mostly unknown to the
workforce at the time, but by meticulous efforts and team-sprit, these problems were
surmounted and the rated capacity production was achieved only within a year of
integrated operation of the plant.
Thereafter, the plant was expanded to 2.5 MT capacity per year, and then to 4 MT of crude
steel per year, with Soviet assistance.
All the units of the plant have been laid out in sequential formation according to
technological inter-relationship so as to ensure uninterrupted flow of in-process materials
like Coke, Sinter, Molten Iron, Hot Ingots, as well as disposal of metallurgical wastages and
slag etc., minimizing the length of various inter-plant communications, utilities and services.
BSP is the sole manufacturer of rails and producer of the widest and heaviest plates in India.
Bhilai specializes in the high strength UTS 90 rails, high tensile and boiler quality plates, TMT
bars, and electrode quality wire rods. It is a major exporter of steel products with over 70%
of total exports from the Steel Authority of India Limited being from Bhilai. The distinction
of being the first integrated steel plant with all major production units and marketable
products covered under ISO 9002 Quality Certification belongs to BSP. This includes
manufacture of blast furnace coke and coal chemicals, production of hot metal and pig iron,
steel making through twin hearth and basic oxygen processes, manufacture of steel slabs
and blooms by continuous casting, and production of hot rolled steel blooms, billets and
rails, structural, plates, steel sections and wire rods. The plant's Quality Assurance System
has subsequently been awarded ISO 9001:2000.
Not content with the Quality Assurance system for production processes, Bhilai has one in
for ISO 14001 certification for its Environment Management System and its Dalli Mines.
Besides environment-friendly technology like Coal Dust Injection System in the Blast
Furnaces, de-dusting units and electrostatic precipitators in other units, BSP has continued a
vigorous afforestation drive, planting trees each year averaging an impressive 1000 trees
per day in the steel township and mines.

5. P a g e | 5
A leader in terms of profitability, productivity and energy conservation, BSP has maintained
growth despite recent difficult market conditions. Bhilai is the only steel plant to have been
awarded the Prime Minister's Trophy for the best integrated steel plant in the country seven
times.
Bhilai Steel Plant, today, is a panorama of sky-scraping chimneys and blazing furnaces as a
modern integrated steel plant, working round the clock, to produce steel for the nation.
Bhilai has its own captive mines spread over 10929.80 acres. We get our iron ore from
Rajhara group of mines, 85 kms south-west of Bhilai. Limestone requirements are met by
Nandini mines, 20 kms north of Bhilai and dolomite comes from Hirri in Bilaspur district, 135
kms east of the plant. To meet the future requirement of iron ore, another mining site
Rowghat, situated about 100 km south of Rajhara, is being developed; as the ore reserves at
Rajhara are depleting. Bhilai expanded its production capacity in two phases - first to 2.5 MT
which was completed on Sept. 1, 1967 and then on to 4 MT which was completed in the
year 1988. The plant now consists of ten coke oven batteries.
Six of them are 4.4 meter tall. The 7 meter tall fully automated Batteries No 9 & 10 are
among the most modern in India. Of Bhilai's seven blast furnaces, three are of 1033 cu.
meter capacity each, three of 1719 cu. meter and one is 2000 cu. meter capacity. Most of
them have been modernized incorporating state-of-the-art technology.
Steel is made through twin hearth furnaces in Steel Melting Shop I as well as through LD
Convertor -continuous Casting route in SMS II. Steel grades conforming to various national
and international specifications are produced in both the melting shops. Production of
cleaner steel is ensured by flame enrichment and oxygen blowing in SMS I while secondary
refining in Vacuum Arc Degassing ensures homogenous steel chemistry in SMS II. Also in
SMS II is a 130 T capacity RH (RuhshatiHeraus) Degassing Unit, installed mainly to remove
hydrogen from rail steel and Ladle Furnace to meet present and future requirements of
quality steel. Bhilai is capable of providing the cleanest and finest grades of steel.
The rolling mill complex consists of the Blooming & Billet Mill, Rail & Structural Mill,
Merchant Mill, Wire Rod Mill and also a most modern Plate Mill. While input to the BBM
and subsequently to Merchant Mill and Wire Rod Mill comes from the Twin Hearth
Furnaces, the Rail & Structural Mill and Plate mill roll long and flat products respectively
from continuously cast blooms and slabs only. The total length of rails rolled at Bhilai so far
would circumvent the globe more than 4.5 times.
To back this up, we have the Ore Handling Plant, three Sintering Plants – of which one is
most modern, two captive Power Plants with a generating capacity of 110 MW, two Oxygen
Plants, Engineering Shops, Machine Shops and a host of other supporting agencies giving
Bhilai a lot of self-sufficiency in fulfilling the rigorous demands of an integrated steel plant.
Power Plant No.2 of 74 MW capacity has been divested to a 50:50 SAIL/NTPC joint venture
company. The plant has undertaken massive modernization and expansion plan to produce
7.5 MT of hot metal by the year 2010.

6. P a g e | 6
MARS-2
1.1 An Introduction to MARS-2
MARS is popularly known as Machine Shop. MARS stands for Machining, Assembly and Re-
Engineering Services. There are three units of the MARS named as MARS-1, MARS-2 and
MARS-3. MARS-2 was established during 4MT expansion project to take care of machining
and assembly jobs of Converter, Continuous Casting Shop and Plate Mill. The shop has got
two machining bays (Light Bay and Heavy Bay 78 x 24m) and one Assembly Bay (72 x 24m)
which forms a Tee with the machining bays. It has got the working area 5161m2 and
electrical power supply of 1 MVA.
Past and Present
MARS-2 started with manpower of 128. The present strength is only 86. Initially MARS-2
was dedicated to 4 MT expansion but presently it is dealing with almost all the major shops
of BSP.
Specialization
MARS-2 has following bays
 Light Bay- for light machining
 Heavy Bay- for heavy machining
 Assembly Bay- for assembly work
Capacity
Annual machining capacity- 2200 T
Annual assembling capacity- 6000T
Main assemblies done are 5-roll set, 8-roll set, 10-roll set and pinch rolls used in Continuous
Casting Shop.
Machining Jobs
Following important high value items are machined
 Slide Block of Plate Mill
 Inserts for Continuous Casting Shop
 Hammer plates of Sintering Plant 2 and 3
 Top Tie rod of Coke-Oven
 New wheels from various departments
Repairingand Reclamation Jobs
 Pinch roll of Slab and Bloom Caster
 Truing of 230 diameter roller of Continuous Casting Shop
 Roll table cylindrical roller of Plate Mill
 Reclamation of various wheels

7. P a g e | 7
 Partening of magnet of Continuous Casting Shop and Plate Mill
 Reclamation of ribbed roller of Plate Mill
AssemblyJobs
 5-roll set of Continuous Casting Shop
 10-roll set of Continuous Casting Shop

8. P a g e | 8
 Tong assembly of Continuous Casting Shop
 Breast roll assembly of Plate Mill
 Mudgun Barrel assembly of Blast Furnace

9. P a g e | 9
 Mudgun Column assembly of Blast Furnace
 Dedusting Fan of Sintering Plant-3
 Reducer assembly
 Eccentric and input/output shaft assembly
 Wheel assembly
Main Equipment(s)
MARS-2 is one of the most well equipped machine shop in BSP. It boasts of series of highly
useful machines like Vertical Boring Machine (1 No), Horizontal Boring Machine (1 No), HMT
lathe (8 Nos). MARS-2 also consists of 1 Cylindrical Grinding Machine, 1 Heavy duty Lathe, 1
Plano Milling Machine, 1 HMT Horizontal Milling Machine, 1 HMT Universal Milling Machine
etc. beside these, it has 2 Slotting Machine, 1 Shaping Machine, 1 Thread Cutting Machine
and 2 Auto Welding Machine too.
MARS-2 Crane Details
MARS-2 has 3 overhead cranes each in Heavy, Light and Assembly bays
 Assembly Bay cranes- 50/10 T capacity
 Heavy Bay cranes- 20/5T capacity
 Light Bay cranes- 10/5 T capacity

10. P a g e | 10
1.2 Annual Production in MARS-2
 Manufacturing of High Value Items :
S.N. Names of Items Qty. Total Value (Rs.)
1 Slide Block (Insert) of CCS 68 81,600
2 Slide Block (PPM-548) for Plate Mill 18 2,61,000
3 Slide Block of Plate Mill Main Stand 27 54,00,000
4 Hammer Plates of SP-3 1176 19,20,408
5 Machining of New Wheels 46 9,27,406
6 Tie Rods Size M48X16 Mtr. of Coke Oven 22 3,85,000
Total Value (Rs.) 89,75,414
 Repair & Reclamation of High Value Items :
S.N. Names of Items Qty. Total Value (Rs.)
1 Vertical Roll of R & S Mill 27 10,12,500
2 Pinch Roll of CCS 156 2,24,07,216
3 Breast Roll of P/Mill 6 13,33,332
4 Motorised Tong Assembly of CCS 3 9,00,000
5 Welding of Various Sizes 168 34,99,944
6 Hydraulic Mud Gun Assembly 4 20,00,000
7 Dia. 230 Roller of 8 Roller set 176 68,74,912
8 Reclamation of Dia. 450 Cylindrical Roller of
Plate Mill
16 32,00,000
9 Reclamation of Dia. 300 Roller of Plate Mill (
Welding & Machining)
6 20,66,670
10 Reclamation of Dia. 350 & 450 Ribbed Roller of
Plate Mill
18 72,00,000
Total Value (Rs.) 5,04,94,574
 Important Assemblies for CCS Operation :
 5 Roll Set Assembly – 91 Sets
 8 Roll Set Assembly – 12 Sets
 10 Roll Set Assembly – 35 Sets
So, total no. of CCS operations = 138 Sets

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1.3 Cost Control of MARS-2 during 2015-2016
 Saving in Bearing :
S.
N.
Names of
Items
Bearing
Used
New
Bearing
Reclamation
Bearing
Value
Per
Piece
Total
Saving
1 5 Roll Set
Bearing
No. 6212
5460 1415 4045 419 16,94,855
2 8 Roll Set
Bearing
No. 22220
384 42 342 3564 12,18,888
3 10 Roll Set
Bearing
No. 22213
2800 773 2027 2000 40,54,000
Total Value (Rs.) 69,67,743
 Steps taken to Save Bearing :
 By removing old bearing from the sets.
 By cleaning properly then checking.
 By assembling properly with sufficient grease.
 Cost Control In Maintenance :
S.N. Name Of Items Qty. Total Value (Rs.)
1 Saving Of Head Stock of Lc-100 Lathe Machine
By Sleeving Bearing Seating
1 50,000
2 In-House Repair Of Lubrication Oil Pump Of
45 Lathe Machine
1 20,000
3 Repair Of Feed Mechanism Of Horizontal
Boring Machine
1 30,000
Total value (Rs.) 1,00,000

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 Total Saving :
 Saving in Manufacturing of High Value Items = 89,75,414
 Saving in Repair & Reclamation of High Value Items = 5,04,94,574
 Saving in Bearing = 69,67,743
 Saving in Maintenance = 1,00,000
So, the Total Saving = 6, 65, 37,731.
 Saving In Power Consumption:
 Total Consumption of Electricity during 2014-2015 - 648500 KWH
 Total Consumption of Electricity during 2013-2014 – 750690 KWH
 Saving in Power Consumption during 4 year – 102190 KWH
 Steps Taken For Power Reduction :
 Over Hauling of Heavy Duty Motors & Generators.
 Switching off Machines, Fans and ACs & Coolers etc. during idle time.
 Switching off of MG Sets.
 Saving In Oil Consumption :
 Total Oil Consumption during 2013-2014 - 4430 Litres.
 Targeted reduction in Oil consumption for 2014-2015 – 3390 Litres.
 Saving in oil consumption in current year – 1040 Litres.
 Steps Taken For Reducing Oil Consumption :
 By stopping leakages from Machines.
 By properly handling in Oil store room.
 By taking care at the time of pouring oil in machines.
 MARS – 2 Certification :
MARS -2 has following important certifications:
 IMS Certification (Includes OHSMS, EMS & SAMS)
 5S Certification

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 Manpower Statistics in MARS-2 :
 MARS-2 Awards & Rewards :
MARS-2 has got following awards:
 NATIONAL SAFETY AWARD for various categories.
 BEST HOUSEKEEPING AWARD.
 ED (W) Skill competition award.
0
20
40
60
80
100
120
2006-07 2007-08 2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 2015-16
Manpower
Years
Manpower over the Years
Executive 4 4 4 4 4 3 3 3 3 4
Non-
Executive
107 106 102 101 99 91 88 86 82 70

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BLAST FURNACES
2.1 INTRODUCTION – Iron Production
Basics:
The first step in the production of steel is to produce iron, and iron production involves
separating iron from iron ore. There are mainly three basic methods of producing iron:
Direct Reduction, Iron Smelting and the Blast Furnace method. Direct Reduction method
includes both gas and coal based processes. The product
coming out of these processes (Sponge Iron or Direct Reduced Iron) is in the solid state.
Electric Arc Furnace follows DRI process for the production of crude steel.
In Iron smelting process coal and iron ore fines are used as charge materials and liquid
product will come out of the furnace, example Corex process. EAF or BOF route is
followed for steel making.
For achieving high production rates with great degree of heat utilization Blast Furnace
(BF) route is the most economical way till date. So Bhilai Steel Plant, which is an ore
based Integrated Steel Plant had chosen Coke ovens – Blast Furnace – BOF
/ THF route for the production of crude steel.
What is a Blast Furnace? BF is a counter current heat and mass exchanger, in which solid
raw materials are charged from the top of the furnace and hot blast is sent through the
bottom via tuyeres. The heat is transferred from the gas to the burden and oxygen from
the burden to the gas. Gas ascends up the furnace while burden and coke descend down
through the furnace. The counter current nature of the reactions makes the overall
process an extremely efficient one.
In the blast furnace process iron ore and reducing agents (coke, coal) are transformed to
hot metal, and slag is formed from the gangue of the ore burden and the ash of coke and
coal. Hot metal and liquid slag do not mix and remain separate from each other with the
slag floating on top of the denser iron. The iron can then be separated from the slag in
the cast house. The other product from the Blast Furnace is dust laden blast furnace gas,
which is further cleaned in the gas cleaning plant and is used as a fuel all over the plant.

15. P a g e | 15
2.2Blast Furnace constructional features:
A blast furnace has a typical conical shape. The sections from top down are:
 Throat, where the burden surface is.
 The shaft or stack, where the ores are heated and reduction starts.
 The bosh parallel or belly and
 The bosh, where the reduction is completed and the ores are melted down. The
hearth, where the molten material is collected and is cast via the taphole.
Fig. 1 Schematic cross section of the Blast Furnace
2.3Blast Furnace process:
The basic raw materials and their functions:
 Iron Ore: Iron bearing materials; provides iron to the Hot Metal

16. P a g e | 16
 Sinter: Iron bearing material. Fines that are generated in the plant are effectively
utilized by converting them to sinter. Provides the extra lime required for the iron
ore that is charged in the blast furnace.
 Coke: Acts as a reductant and fuel, supports the burden and helps in maintaining
permeable bed.
 Limestone: Acts as Flux. Helps in reducing the melting point of gangue present in the
iron bearing material
 Manganese Ore: Acts as additive for the supply of Mn in the Hot Metal
 Quartzite: Acts as an additive
 Coal Dust: Acts as an auxiliary fuel, reduces coke consumption in the BF
 Coal Tar: Acts as an auxiliary fuel, reduces coke consumption in the BF
 Pellets: Iron bearing materials. Although not in use right now, there is a proposal to
utilize the fines below the sinter grade for pellet manufacturing and the pellets
formed are going to be charged in the BF.
The specifications of the above materials is given in Table
Table 1. SPECIFICATIONS OF RAWMATERIALS
Material Chemical
Analysis
Specification Size Other Properties
Iron Ore Fe 64.0 % min. 10-40 mm
(Lumps) SiO2 2.5 ± 0.5 %
P 0.10 % max. Softening
Melting
range:
Al2O3 / SiO2 0.88 % max. 1175 - 1540
?C
Sinter Fe 50% 5-40 mm
FeO 10%
SiO2 6% RDI: 23 - 25
Al2O3 3%
CaO 14-15 % Softening
Melting
range:
MgO 4-5% 1330 – 1600
o
C
Coke Ash 15-16 % 52 -55 mm CRI: 22 -24

17. P a g e | 17
max.
VM 0.3-0.4 % CSR: 60 min.
M 5 ± 0.5 % M40: 80 – 82
%
S 0.5-0.6 % M10: 7.8 –
8.4%
C 75-80 %
Limestone CaO 38% Min. 6-50 mm
SiO2 6.5 ± 0.25 %
MgO 8.5 ± 0.5 %
LD Slag CaO 40.8 ± 1 % 10-40 mm
MgO 10.5 ± 0.5 %
SiO2 15.50%
Mn Ore Mn 30 % min. 25-80 mm
SiO2 30 % max.
Al2O3 5 % max.
P 0.30 % max.
CDI Coal Ash 9 – 11 % 90 microns
VM 28%
Moisture 1.80%
FC 56%
Quartzite SiO2
Al2O3
96 % min.
1.5 % max.
25 -50 mm
The raw materials from various places are transported to the bunkers placed near the
furnaces and properly screened and weighed. These batched proportions of the raw
materials are conveyed to the top of the blast furnace via skip car or conveyors and are
charged in the blast furnace. The distribution is maintained in such a fashion that alternate
layers of coke and iron-containing burden (sinter and iron ore) are formed inside the BF. The
blast, which is heated in the stoves, is called Hot Blast and this is blown into the BF via
tuyeres. The hot blast gasifies the reductant components in the furnace, those being coke as
well as auxiliary materials injected via the tuyeres. In this process, the oxygen in the blast is
transformed into gaseous carbon monoxide. The resulting gas has a high flame temperature
of between 2,100 and 2,300°C. Coke in front of the tuyeres is consumed thus creating
voidage.

18. P a g e | 18
The very hot gas ascends through the furnace, carrying out a number of vital functions.
◉ Heats up the coke in the bosh/belly area.
◉ Melting the iron ore in the burden, creating voidage.
◉ Heats up the material in the shaft zone of the furnace.
◉ Removes oxygen of the ore burden by chemical reactions.
◉ Upon melting, the iron ore produces hot metal and slag, which drips down through
the coke.
zone to the hearth, from which it is removed by casting through the tap hole. In the dripping
zone the hot metal and slag consume coke, creating voidage. Additional coke is consumed
for final reduction of iron oxide and carbon dissolves in the hot metal, which is called
carburisation.
Thus the liquid products Hot Metal and Slag settle in the Hearth. These two products are
removed periodically from the blast furnace. The process is called tapping the blast furnace.
The other gaseous product, which is going to the top of the furnace, contains dust in it. It is
cleaned in the Primary (dust catcher); Secondary (ventury and scrubber) and Tertiary
(electro static precipitator) gas cleaning system and the cleaned gas is used as a fuel all over
the plant.
It will take minimum 6-8 hours for the solid raw materials that are charged from the top to
reach the bottom, whereas gaseous products that are sent through the tuyeres will go out
in 2-8 seconds.
The efficiency of the process is judged by two parameters:
 Productivity: The amount of Hot Metal produced per cubic meter of the furnace
volume in a day.
Unit: tonnes/m3/day (either on Working Volume or Useful volume basis)
 Fuel Rate: The amount of fuel required to produce one tonne of hot metal.
Unit: kg/ton. (Includes coke rate + aux. Fuel rate + nut coke rate (added in sinter)).
(Carbon rate is the right measure as carbon content of the fuel varies from time to
time).
Continuous monitoring of the top gas analysis will give an indication about the
furnace efficiency.
2.4 Reactionsin the BlastFurnace:
UPPER STACK ZONE
 Reduction of Oxides
 3 Fe 2O3 + CO = 2 Fe3O4 + CO2
 Fe3O4 + CO = 3FeO + CO2

19. P a g e | 19
 FeO + CO = Fe + CO2
 Decomposition of Hydrates
 Water - Gas Shift Reaction CO + H2O = CO2 + H2
 Carbon Deposition
 Decomposition of Carbonates
Fig. 2 Isothermal Zones in BF
MIDDLE STACK ZONE
 Direct / Indirect Reduction
FeO + CO = Fe + CO2
CO2 + C = 2CO
FeO + C = Fe + CO
 Gas utilization
LOWER STACK ZONE
 Calcination of Limestone
Reduction of Various elements
Reduction of unreduced Iron
Reduction of Silicon
 Reduction of Mn, P, Zn etc.

20. P a g e | 20
 Formation / melting of slag, final reduction of FeO and melting of Fe.
COMBUSTION ZONE
 Burning and combustion of Coke
C+O2 = CO2 + 94450 cal (direct reduction)
CO2+C = 2CO - 41000 cal (solution loss reaction)
 Complete reduction of Iron Oxide
RACEWAY
 Coke and Hydrocarbons are oxidized
 Large evolution of heat
HEARTH
 Saturation of Carbon with Iron
 Final Reduction of P, Mn, Si and Sulphur
 Reaction impurities reach their final con- centrations
 Falling/drop of Metal and Slag bring heat down into the Hearth.
Different isothermal zones can be seen in Fig. 2.
2.5 THE FACILITIES AT BSP:
The Blast Furnace Department of Bhilai Steel Plant is operating 7 Blast Furnaces.
All these furnaces are commissioned in various phases of modernization. In the
first phase when plant is at 1 MT stage BF No. 1, 2, and 3 are commissioned.
During the second phase of expansion i.e. in 2.5 MT stage BF No. 4, 5, and 6 are
commissioned. In 4.0 MT expansion phase BF No.7 is commissioned. Further
capacity enhancement took place recently (February, 2007) by modernizing BF
No 7. The furnace capacities and their commissioning dates, with major
> 11 0 0 °C
60 0- 900 ° C
90 0- 110 0 ° C
< 60 0° C

21. P a g e | 21
modifications are given in Table 2. At present the annual rated capacity of Hot
Metal is 4.7 MT.
Table 2. BF COMMISSIONING AND RECOMMISSIONING
DETAILS
Phase
Commissioni
ng date
Recommissioned
after
modernization
Major modifications during
modernization
1 MT 04-02-1959 15-08-
1988
Complete conveyorisation
of charging with full
automation, eliminating
conventional scale
car system.
1 MT 28-12-1959
Complete conveyorisation
of charging with full
automation, eliminating
conventional scale
car system.
1 MT 28-12-1960 15-07-
1998
RCU, Stock
house
Conveyorisation
Phase Commissioni
ng date
Recommi
ssioned
after
moderniz
ation
Major modifications during
modernization
2.5
MT
8-12-1964 8-12-
1989
Stock house conveyorisation
with elimination of scale car
Paul Wurth Bell less top.
A separate charging
operators control room.
Twin tap hole arrangement.
Cast house slag granulation
INBA type.
2.5
MT
27-11-1966 27-09-
1992
Stock house conveyorisation
with elimination of scale car;
Paul Wurth Bell less top.
A separate charging
operators control room.
Twin tap hole arrangement.
Cast house slag granulation
INBA type
A supervisory control system
was adopted
Hydraulic mud
guns and
drilling machines replacing
the
electo-mechanical
counterparts. Castable

22. P a g e | 22
runners
2.5
MT
31-07-1971 7-12-
1990
Stock house conveyorisation
with elimination of scale car;
Paul Wurth Bell less top.
Twin tap hole arrangement.
4 Nos. of old Russian stoves
were replaced by 3 nos of
hoogovens stoves.
4.0
MT
30-8-1987 22-2-
2007
Capacity enhanced to
1.55 MT/annum
Cu staves cooling provided
Flat Cast House
Some more modifications during modernizations:
Introduced Coal Dust Injection in BF#6 to achieve low coke rate, extended to BF#7, 1 and 5.
 Tar Injection facility for BF # 2 and 3.
 Castable Runners in all furnaces except in Fce # 1,2, &3.
 In all furnaces, stoves are operated in auto mode.
 Sinter Screening facilities in every furnace.
 Usage of Tar bonded clay for closing the tap hole.
 Hydraulic mud guns and drilling machines.
The main dimensions of all the furnaces are given in table 3.
Table 3. MAIN DIMENSIONS OF BLAST FURNACES
BF--> 1,2,3 4,5,6 7
DIMENSIONS
Useful Volume (top of the Hearth to
stock level)
1033 m3
1719 m3
2355 m3
Working Volume (Tuyere to stock
level) 886 m3
1491 m3
2105 m3
Full Height , mm 28750 31250 32350
Useful Height, mm 26000 28500 29700
Top Height, mm 2300 1900 2300
Top Dia., mm 5800 6000 7800
Large Bell Dia., mm 4200 No bells No bells
Stack Height, mm 15000 17800 17700
Stack Angle 85° 25’ 34’’ 84° 42’ 18’’ 84° 36’
Bosh Height, mm 3000 3000 3300
Belly Height, mm 2000 2000 2225
Bosh Dia, mm 8200 10200 12135

23. P a g e | 23
Bosh Angle 80° 32’ 15” 79° 36’ 48” 72° 50’
Hearth Height, mm 3200 3200 3400
Hearth Dia., mm 7200 9100 9750
No of Tuyeres 14 18 24
No of Tap holes 1 2 2
Monkey 1 0 0
The equipment and other details of BF's are shown in table 4.
Table 4. EQUIPMENT AND OTHER DETAILS OF BLAST FURNACES AT
BSP
BF # 1 BF # 2 BF # 3 BF # 4 BF # 5 BF # 6 BF # 7
COOLING
? ? ? ? ? ? ?
Stack
Cooing Cantilever
coolers
Cantilever
coolers
Cantilever
coolers
Plate
Coolers
Plate
coolers
Plate
coolers Cu staves
TOP
Type Doubl
e Bell
Double
Bell
Double
Bell with
RCU
BLT
with
single
bin
BLT
with
single
bin
BLT
with single
bin
BLT with
double bin
Charging
System
Skip car Skip car Skip car
Skip
car
Skip
car
Skip
car
Skip car
Top
Pressure
1.0 1.0 1.0 1.1 1.1 1.1 1.8
Cast House Single Single Single Single Single Single Double
Tap Holes 1 1 1 2 With
40O
apart
2 with
40O
apart
2 with
40O
apart
2 with
180 O
Apart
Monkey 1 1 1 0 0 0 0

24. P a g e | 24
Slag
Granulation
Nil, slag
collected
in ladles
Nil, slag
collected
in ladles
Nil, slag
collected
in ladles
INBA
SGP
INBA SGP CAST
HOUSE
SGP
2LINES
CAST
HOUSE
SGP
2 X 2 LINES
Mud gun Electric Electric Hydraulic Electric Hydraulic Hydraulic Hydraulic
Drill
Machine
Electric Electric Hydraulic Electric
Twin
Taphole
Hydraulic Hydraulic Hydraulic
STOVES
NO 3 3 3 4 4 3 4
Design Russian Russian Russian Russian Russian Hoogove
n
s
Russian
Combustion
Chamber
Internal,
Horizon
tal fired
Internal,
Horizon
tal fired
Internal,
Horizonta
l
fired
Internal,
Horizont
al
fired
Internal,
Horizonta
l
fired
Internal,
Vertical
fired
Internal,
Horizontal
fired
AUXILI ARY FUEL
INJECTION
CDI CTI CTI NIL CDI CDI CDI

25. P a g e | 25
A BRIEF DISCUSSION ON MUDGUN
3.1 Introduction
The operation of a blast furnace is a continuous process. The blast furnace
continues to produce liquid iron (hot metal) and slag as long as it is in operation. The hot
metal and slag accumulate in the hearth of the furnace, but since there is a limit to the
amount that can be accumulated before it interferes with the furnace operation, hot metal
and slag must be removed from the furnace at regular intervals.
The tap hole is used for tapping the hot metal from the furnace. It is located
slightly above the floor of the hearth. Tapping is a process that removes hot metal and slag
from the furnace hearth.

26. P a g e | 26
The hydraulic drives of mud gun machines ensure that any operations with modern heavy
duty tapholes are effective and secure. Mud gun machines are manufactured specifically for
critical heavy duty operations, and their design and technical parameters fully comply with
the requirements of modern technological processes of blast furnace operations.
The basic design and installation requirements for tap hole guns are as follows:
• The mud gun machine is to be powerful enough to extrude the tap hole mass into
the tap hole against the full force of internal pressure of the blast furnace, even
when the pressure rises above normal.
• The machine is to be capable of placing the mouth of the gun correctly in the tap
hole in spite of any obstruction by slags or other material.
• The machine is to be designed to extrude all the tap hole mass for the plug.
• It is to be possible to lock the mud gun machine in various positions.
• All the movements and manoeuvres of the mud gun machine is to be remote
controlled and it is to be possible to stop these at any given time.
• The mud gun machine is to be fitted with a warning siren or buzzer which is to
operate automatically before the mud gun machine is set in motion.
• The mud gun machine is to be installed in such a way that when it is not in use,
operators can move freely around it and carry out repairs on it and there is to be
enough room for one person to pass between the machine and any obstacle.
• Suitable means of protection is to be provided for the personnel working around the
mud gun machine, and it too is to be protected.
OBJECTIVE OF MUDGUN
The intention of this supply is to achieve the minimum criteria for closing the tap-hole of
Blast furnace after Hot metal/slag drain or draining condition.

27. P a g e | 27
MUDGUN BARREL ASSEMBLY OF BLAST FURNACE
MUDGUN COLOMN Assembly of Blast Furnace

28. P a g e | 28
3.2 Location of Mudgun and Blast Furnace Tap Hole
and Tapping of Furnace
Fig. Location of MUDGUN assembly in Blast furnace
The operation of a blast furnace is a continuous process. The blast furnace continues to
produce liquid iron (hot metal) and slag as long as it is in operation. The hot metal and slag
accumulate in the hearth of the furnace, but since there is a limit to the amount that can be
accumulated before it interferes with the furnace operation, hot metal and slag must be
removed from the furnace at regular intervals. The tap hole also known as iron notch, is
used for tapping the hot metal from the furnace. It is located slightly above the floor of the
hearth.
Regardless of the specific tap hole configuration or operating philosophy, due to the
addition of dynamic (often periodic) and more intense process conditions (exposure to

29. P a g e | 29
higher temperatures leading to accelerated corrosion, greater turbulence, and elevated
rates of mass and heat transfer), and higher concurrent thermo-mechanical forces (from
thermal or flow shear stresses), the performance and longevity of the blast furnace is
intimately linked to the performance of the tap hole. Hence tap hole is very critical to the
blast furnace. It is the heart and the lifeline of the blast furnace since without a tap hole a
blast furnace cannot exist. The criticality and relevance of tap hole continues even in the
modern automated blast furnaces.
Tap hole is an essential part of a blast furnace. Large furnaces usually have 2 to 4 tap holes
and the drainage of hot metal and slag is practically continuous by periodically drilling and
plugging the tap holes with one of the tap holes is always open and two alternate tapings
usually overlap for some period of time. Medium or small sized blast furnaces have normally
one tap hole and the time interval between two tappings generally varies from 30 min to 90
min. Some blast furnaces are equipped with a slag (cinder) notch (generally referred to as
the monkey) for removing slag from the blast furnace and it is located in a plane typically 1
m to2 m above the tap hole.
In earlier days when the burden of the blast furnace was not improved to present standards,
the weight of the slag produced in the blast furnace was more than half the weight of the
hot metal. The lower density of the slag caused it to fill up the space in the hearth above the
metal, and it would interfere with the penetration of the blast air and the combustion
process at the tuyeres long before the accumulation of hot metal had reached the desired
amount for tapping. Hence it was necessary to remove the excess slag through the slag
notch once or twice between two tappings. However presently because of better prepared
burdens, the slag volumes are at around 250–320 kg/ton level. Therefore the monkey is
seldom used and the slag is typically removed only through the tap hole during the blast
furnace tapping.
Tapping, also referred to as casting or drainage, is a process that removes hot metal and slag
from the furnace hearth. The tapping process critically determines the in-furnace gas
pressure and residual amounts of iron and slag in the hearth. Poor hearth drainage usually
leads to unstable furnace operation which is generally connected to marked losses in
furnace productivity and campaign life. An inefficient tapping also gives rise to excessive
accumulation of liquids and thus high liquid levels in the hearth. If the liquid slag approaches
the tuyeres level, the reducing gas flow in the bosh is severely disturbed, often resulting in
irregular burden descent.
A tapping cycle begins as the tap hole is drilled open and is terminated by plugging the tap
hole with the tap hole mass when the furnace gas bursts out. At the end of the tapping, the
gas-slag interface tilts down towards the tap hole and a considerable amount of slag
remains above the tap hole level. The iron phase can be drained from levels below the tap
hole because of the large pressure gradient that develops near the tap hole in the viscous
slag phase. The average slag-iron interface is therefore lower than the tap hole level.

30. P a g e | 30
Depending on a number of factors, such as liquid production rates, hearth volume and
tapping strategies, the initial stage of a tapping cycle varies and can be categorized as
follows.
 Iron first -This occurs if the slag-iron interface is above the tap hole level when the
tap hole is drilled open. The tapping cycle starts with an outflow of iron only, and
slag starts flowing later when the slag-iron interface has descended to the tap hole.
After this, iron and slag are drained simultaneously until the end of the tapping. The
time elapsed from the start of the tapping until slag enters the runner is called the
slag delay.
 Simultaneous – This pattern appears if the slag-iron interface lies in, or at a finite
depth below the tap hole when the tapping commences. The high pressure gradient
in the slag phase can promote iron flow, or even drags iron up from below the tap
hole. As a result, iron and slag are drained together during the whole period of
tapping.
 Slag first- This is opposite to the iron first pattern. In this pattern slag flows out
initially and iron after a delay. This is because the slag-iron interface is far below the
tap hole as the tapping begins, and the phenomena can be observed in larger
furnaces with multiple tap holes. The pressure gradient caused by the viscous slag is
initially inadequate to lift iron up.
A primary requirement of tapping is to secure reliably the desired rate of furnace products.
Thus, establishing the factors influencing tapping rate are important. Normally in large blast
furnaces tapping rates of 7 ton/min, and liquid tapping velocities of 5 m/sec, in tap holes of
70 mm diameter and 3.5 m long, are typically encountered. Tap hole condition and tap hole
length strongly influence the tapping rate. When the blast furnace is in operation, the tap
hole is completely filled with a refractory material known as the tap hole mass.
Tap hole is normally exposed to an extremely dynamic environment with high temperature
and pressure, frequent drilling and plugging, substantial chemical attack, and flow induced
shear. During tapping, the tap hole is gradually eroded as the molten liquids flow through it.
The greater the wear of the tap hole, the greater is the change in the liquid flow rates and
the greater is the variation of liquid levels in the hearth. For the maintenance of a stable
state at the tap hole thus facilitating the liquid removal from the hearth, an excess of high
quality blast furnace tap hole mass is, in practice, injected in the tap hole when a tap is
terminated. The tap hole mass accumulates and solidifies on the inside of the tap hole
forming a protective layer with the shape of a ‘mushroom’, which is mainly concentrated
directly below the tap hole and to a lesser extent sideways and above the tap hole. The tap
hole therefore becomes longer than the depth of the corresponding hearth sidewall through
which the tap hole is drilled. A longer tap hole can drain molten liquids from the inner part
of the hearth and the circumferential flow can be suppressed. Also, longer tap holes can
result in decreased drainage rates due to the frictional effect and thus lower the
consumption of the tap hole mass. The size and shape of the mushroom layer has also have
significant effect on the temperature variations of hearth lining during tapping.

31. P a g e | 31
When the time arrives for the furnace to be tapped, the tap hole need to be opened. It is
essential that the tap hole is quickly and certainly be opened whenever required.
Discounting the most primitive past practices of ‘pricking’ or ‘excavating’ for the opening of
tap hole, a wide range of tap hole opening methods are adopted which include the
following.
 Manual oxygen lancing of the tap hole. This is normally to be minimized or during
emergency only. It can lead to blister tap hole failure and can result into explosion.
 Drilling by drilling machine which can be electrically, pneumatically or hydraulically
operated. The tap hole is drilled open using a drill rod of appropriate diameter and
length in the drilling machine. The drill machine generally has both rotational and
hammer capabilities. Normally, rotation only is required to open the tap hole, but if
the tap hole mass is very hard just before the full length is reached, it might be
necessary to utilize the hammer action. This, however, is avoided wherever possible
as it damages the tap hole and the ‘mushroom’.
 Soaking bar technique – Soaking bar practice found favour in the furnace tapping as
an emerging development to replace tap hole drilling in the 1980s. It involved
pushing/hammering a 50 mm bar through the tap hole mass in the tapping channel.
This promised to provide improved thermal conductivity from the inner hearth up
the tapping channel to better bake and sinter tap hole mass. To open the tap hole,
the bar was reverse hammered out of the tapping channel, now of well defined
dimension, and with the promise of no risk of skew drilling or oxygen lancing
damage. However, the practice had fallen out of favour by the 1990s, for reasons of
requiring time consuming pre drilling to assist with soaking bar insertion, difficulty in
accurately assessing the all critical drill depth and matching it to optimal tap hole
mass addition, shorter tap hole mass curing times with increased risk of tap hole self
opening, and other tap hole and ‘mushroom’ damage induced by hammering in bar
installation and removal.
 Combination of drilling without opening, and deliberate lancing of the last remaining
portion of the tap hole.
3.3 Parts used in the MUDGUN Assembly
A MUDGUN assembly generally consists of a MUDGUN BARREL and MUDGUN COLOMN.
Material of construction
a) Base Frame & Linkage:
b) Body:
c) Mud Barrel :
d) Mud Barrel Tip :
IS 2062 & MS/C45
IS 2062
Seamless Pipe
Steel casing / s.s.
Mud-Gun consists of a Pedestal with a vertical column holding the swiveling Boom. The
Boom swivels through a gear train operated by a Hydraulic Motor.Boom holds the Barrel

32. P a g e | 32
Unit comprising of Nozzle, [Heat shielded] Barrel, Stroke Indicator, Hydraulic-Cylinders,
Levers and other accessories. During closing, the Mud Gun is brought to tap hole, aligned
and clamped by another Hydraulic Cylinder. Then the mud pushed by actuating the pushing
Cylinder. The Mud Gun assembled with Swivel Joint & Hose-less piping system. Power pack
facilitates to operate the hydraulic actuators.
The MUDGUN Column assembly consists of the following parts:
 BASE FRAME
 HYDRAULIC CYLINDER(INSIDE MUDGUN COLUMN)
a) Bore Dia.: 125mm
b) Rod Dia.: 90mm

33. P a g e | 33
c) Stroke: 400mm
d) Barrel Mounting: STD.
f) Piston Rod Mounting : STD.
 LEVERS and LINKAGES
LEVER1

34. P a g e | 34
LEVER 2
ASSEMBLY OF LEVER 1 AND LEVER 2 maki T section

35. P a g e | 35
 PIN
 PIN1
D1=107.95mm L1 =63mm
D2=110.06mm L2 =67mm
D3=115.03mm L3 =75mm
Chord(C)=100mm Chord depth(CD)=20mm
 PIN2
D1=119.35mm L1 =73mm
D2=120.36mm L2 =85mm
D3=124.34mm L3 =147mm
Chord(C)=100mm Chord depth(CD)=20mm
D3
D1
D2
L1
L2
L3

36. P a g e | 36
 PIN3(BODY ATTACHED)
D1=108.48mm L1 =74mm
D2=110.15mm L2 =70mm
D3=115.10mm L3 =300mm
Chord(C)=106mm Chord depth(CD)=20mm
 PIN4
D1=120.01mm L1 =87mm
D2=120.25mm L2 =83mm
D3=139.24mm L3 =125mm
D4=139.90mm L1 =47mm
D5=140.75mm L2 =102mm
D6=145.44mm L3 =156mm
Chord(C)=140mm Chord depth(CD)=20mm

37. P a g e | 37
 PIN5
D1=179.25mm L1 =125mm
D2=180.36mm L2 =125mm
D3=190.06mm L3 =130mm
Chord(C)=170.5mm Chord depth(CD)=24mm
 BEARING
The material from which the bearing components are made determines to a large
extent performance and reliability of rolling bearings. For the bearing ring and rolling
elements typical considerations include hardness for load carrying capacity, fatigue
resistance under rolling contact condition, under clean or contaminated lubrication
conditions and the dimensional stability of the bearing components. For the cage,
considerations include friction, strain, inertia forces and in some cases the chemical
action of certain lubricants, solvents, coolant and refrigerants. The relative
importance of these considerations can be affected by other operational parameters
such as corrosion, elevated temperatures, shock loads or combinations of these and
other conditions.
a) BEARING(INSIDE MUDGUN COLUMN BETWEEN LINKAGE)

38. P a g e | 38
SELF ALIGNING BUSH BEARING
b) BEARING (MUDGUN COLUMN)
BALL BEARING

39. P a g e | 39
PREPARATION OF MUDGUN
4.1 Introduction
Since HYDRAULIC MUDGUN is a crucial part of Blast Furnace. it must be maintain in good
working conditions. The function of hydraulic mud gun is to jam tap hole rapidly and
accurately, and into the next cycle of blast furnace operation quickly. HYDRAULIC
MUDGUNS have the function of the light weight, simple structure, smooth operation, stable
and reliable performance, high efficiency, convenient operation, low cost, etc. HYDRAULIC
MUDGUN is one of the perfect equipment of Iron smelting factory before furnace
equipment. HYDRAULIC MUDGUN is composed of gun system, pressure gun, mud device,
hydraulic station, work station and other parts. . The damaged and rejected parts of the
HYDRAULIC MUDGUN, once they are no longer fit to be used, are removed from Blast
Furnace and they are sent to respective repairing and reassembling shops. MARS-2 is
established for repairing of damaged or malfunctioning equipment of the machines of the
various shops including Blast Furnace. In MARS-2 the repairing of HYDRAULIC MUDGUN of
Blast Furnace is done in several steps.
4.2 Descriptionof the process
The whole process can be classified into three basic processes:
A. Dismantling & separating the parts
B. Repair or Reclamation of parts
C. Assembling the HYDRAULIC MUDGUN
A. Dismantling and separating the parts
This process involves several steps which are discussed as below:
1. First of all, the HYDRAULIC MUDGUN must be placed in proper place and cleaned by
removal of all the impurities and dust particles that have accumulated inside the
HYDRAULIC MUDGUN. In Blast Furnace, the liquid metal, dust and Clay get stuck in
the HYDRAULIC MUDGUN, so de-dusting is necessary before further Dismantling
process can be started. In this case, by blowing high pressure air all dust particles are
removed and the semi-solidified metals are often removed by oxy-acetylene flame
cutting.
2. After cleaning, the entire assembly is placed with the help of the crane in such a way
that the HYDRAULIC MUDGUN COLUMN remains in the downward direction and free
for rotation. This particular position is necessary because we have to make
HYDRAULIC MUDGUN COLUMN to be free for motion.

40. P a g e | 40
3. After the job is placed, the pin which connects the hydraulic cylinder with the base
frame is removed.
4. After this, the hydraulic cylinder is detached with the help of crane placing it in
another place.
5. After this, the other body attached pins were removed so that the levers can be
removed.
6. After that, the Levers is detached with the help of crane placing it in another place.
7. Now, once the hydraulic cylinder and the linkages are removed, the bearing housing
is removed with the help of a Bearing Puller.
8. If the bearing gets stuck due to damage or rusting of shaft or due to dust, oxy-
acetylene arc is used for metal gas cutting.
9. In this way, all parts of HYDRAULIC MUDGUN COLUMN are dismantled properly with
the help of various instruments and machines.
B. Repair or Reclamation of parts
The parts of damaged or malfunctioning mudgun can be treated in two manners depending
upon its use and damage:
1. Reclamation & Reuse of parts.
2. Rejection & Replacement of parts.
The bearings, Hydraulic cylinders, levers that are undamaged should be cleaned and
properly greased to be reused again. This method of reusing is known as reclamation.
LubricationinBearing:
If ball bearings are to operate reliably they must be adequately lubricated to prevent direct
metal to metal contact between the rolling elements, raceways and cages. The lubricant
also inhibits wear and protects the bearing surfaces against corrosion. The choice of a
suitable lubricant and method of lubrication for each individual bearing application is
therefore important, as is correct maintenance.
A wide selection of greases and oils are available for the lubrication of ball bearings and
there are also solid lubricants, e.g. for extreme temperature conditions. The most
favourable operating temperatures will be obtained when the minimum amount of
lubricant needed for reliable bearing lubrication is provided. However, when the lubricant
has additional functions, such as sealing or the removal of heat, additional amounts of
lubricants may be required.
The lubricant in a bearing arrangement gradually loses its lubricating properties as a result
of mechanical work, ageing and the build-up of contamination. It is therefore necessary for
grease to be replenished or renewed.

41. P a g e | 41
Defects inHydraulic pistoncylinder:
As cylinder failure can occur for many reasons. Some of the reasons are as follows:
 Damaged piston rods or rod bearings are the most common cause of rod seal failure.
The usual causes of such damage are poor alignment between the cylinder and its
load, resulting in side loading; or a bent piston rod, resulting from the use of an
undersized rod in a thrust application.
 Contaminated fluid can also cause premature rod seal failure. Abrasive particles
suspended in the fluid can damage the seal and the piston rod surface, while
airborne contamination can be drawn into a cylinder via a faulty wiper seal.
 Extreme temperature applications pose two challenges. First, the temperature itself
may limit the choice of seal materials and geometries, second, the fluids used in such
applications often have less lubricity than mineral oil-based fluids.
 High pressure leak, this type of leakage is generally occurs when very high pressure is
used that the seal cannot able to bear this results to leakage.
C. Assembling of the MUDGUN:
The steps to assemble the 10 roll assembly set are as follows:
1. The process of assembling the mudgun starts by assembling the base frame with the
column which is free to rotate by the ball bearing within the base frame and column.
2. Then assembly of levers in t-section with the pin is done.
3. After this, placing the lever assembly with the help of overhanging crane and put it
approximately inside the mudgun.
4. Then placing the pin2 and pin4 and assemble the lever assembly with the mudgun.
5. After this, placing the hydraulic cylinder and put inside the mudgun.
6. Then assembly of the hydraulic cylinder with the lever and the Mudgun is done.
7. In this way, the mudgun assembly gets completed.
4.3 Various Instruments Used in the Reassembling
Process
Micrometer
A micrometer, sometimes known as a micrometer screw gauge, is a device incorporating a
calibrated screw widely used for precise measurement of components in mechanical
engineering and machining as well as most mechanical trades, along with other metrological
instruments such as dial, vernier, and digital calipers. Micrometers are usually, but not
always, in the form of calipers (opposing ends joined by a frame). The spindle is a very
accurately machined screw and the object to be measured is placed between the spindle

42. P a g e | 42
and the anvil. The spindle is moved by turning the ratchet knob or thimble until the object
to be measured is lightly touched by both the spindle and the anvil.
Operating principles
Fig. 4.1 Various types of Micrometers
Micrometers use the principle of a screw to amplify small distances (that are too small to
measure directly) into large rotations of the screw that are big enough to read from a scale.
The accuracy of a micrometer derives from the accuracy of the thread-forms that are central
to the core of its design. In some cases it is a differential screw. The basic operating
principles of a micrometer are as follows:

43. P a g e | 43
The amount of rotation of an accurately made screw can be directly and precisely correlated
to a certain amount of axial movement (and vice versa), through the constant known as the
screw's lead. A screw's lead is the distance it moves forward axially with one complete turn
(360°). (In most threads [that is, in all single-start threads], lead and pitch refer to essentially
the same concept.)
With an appropriate lead and major diameter of the screw, a given amount of axial
movement will be amplified in the resulting circumferential movement.
In some micrometers, even greater accuracy is obtained by using a differential screw
adjuster to move the thimble in much smaller increments than a single thread would allow
A micrometer is composed of:
Frame
The C-shaped body that holds the anvil and barrel in constant relation to each other. It is
thick because it needs to minimize flexion, expansion, and contraction, which would distort
the measurement.
The frame is heavy and consequently has a high thermal mass, to prevent substantial
heating up by the holding hand/fingers. It is often covered by insulating plastic plates which
further reduce heat transference.
Explanation: if one holds the frame long enough so that it heats up by 10 °C, then the
increase in length of any 10 cm linear piece of steel is of magnitude 1/100 mm. For
micrometers this is their typical accuracy range.
Anvil
The shiny part that the spindle moves toward, and that the sample rests against.
Sleeve / barrel / stock
The stationary round component with the linear scale on it, sometimes with vernier
markings. In some instruments the scale is marked on a tight-fitting but movable cylindrical
sleeve fitting over the internal fixed barrel. This allows zeroing to be done by slightly altering
the position of the sleeve.
Lock nut / lock-ring / thimble lock
The knurled component (or lever) that one can tighten to hold the spindle stationary, such
as when momentarily holding a measurement.
Screw

44. P a g e | 44
The heart of the micrometer, as explained under "Operating principles". It is inside the
barrel. This references the fact that the usual name for the device in German is
Messschraube, literally "measuring screw".
Spindle
The shiny cylindrical component that the thimble causes to move toward the anvil.
Thimble
The component that one's thumb turns. Graduated markings.
Ratchet stop
Device on end of handle that limits applied pressure by slipping at a calibrated torque.

45. P a g e | 45
FAILURES IN MUDGUN AND MEASURES FOR
PREVENTION
5.1 Introduction
As the MUDGUN is located at the outside the blast furnace hearth .the operation of a blast
furnace is a continuous process. The blast furnace continues to produce liquid iron (hot
metal) and slag as long as it is in operation. The hot metal and slag accumulate in the hearth
of the furnace, but since there is a limit to the amount that can be accumulated before it
interferes with the furnace operation, hot metal and slag must be removed from the
furnace at regular intervals. The tap hole also known as iron notch is used for tapping the
hot metal from the furnace. It is located slightly above the floor of the hearth.
Hence they have to withstand prolonged exposure to very high temperature. As a result of
such extreme conditions the MUDGUN especially the ball are prone to very high thermal
stresses, stresses developed during contraction, formation of cracks and also wear, tear and
friction. All these phenomenon leads to the failure of the balls and as a result decrease the
working efficiency of the MUDGUN assembly and as a whole the entire Blast furnace. Also
the ball bearing may also undergo failure or get damaged due to a host of reasons like
overloading, internal cracking etc. In this chapter we described the various causes and also
discuss the various measures that can be undertaken in order to prevent the failure of the
parts so affected.
5.2 Failure in bearings – Causes and Cures
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation
between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial
loads. It achieves this by using at least three races to contain the balls and transmit the
loads through the balls. In most applications, one race is stationary and the other is attached
to the rotating assembly. As one of the bearing races rotates it causes the balls to rotate as
well. Because the balls are rolling they have a much lower coefficient of friction than if two
flat surfaces were sliding against each other.
The major causes that have been earmarked for causing bearing failure are namely:-
1. LubricationFailure
According to a recent study, up to 80 percent of bearing failures are caused by improper
lubrication. This includes insufficient lubrication, use of improper lubricants or excessive
temperatures that degrade the lubricant.
What to Look for

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Look for discolored rolling elements (such as blue or brown) and rolling-element tracks as
well as overheating or excessive wear in the bearing.
How to Fix it
Use the appropriate type and correct amount of lubricant, avoid grease loss, and follow
appropriate relubrication intervals.
2. Contamination
Contamination is caused by foreign substances getting into bearing lubricants or cleaning
solutions. These include dirt, abrasive grit, dust, steel chips from contaminated work areas
and dirty hands or tools.
What to Look for
Watch for denting of rolling elements and raceways that cause vibration.
How to Fix it
Filter the lubricant and clean work areas, tools, fixtures and hands to reduce the risk of
contamination.
3. Improper Mounting
In most instances, bearings should be mounted with a press fit on the rotating ring.
What to Look for
A number of conditions can cause denting, wear, cracked rings, high operating
temperatures, early fatigue and premature failure of bearings. These include mounting
bearings on shafts by applying pressure or blows to the outer race, mounting bearings into a
housing by pressing on the inner ring, loose shaft fits, loose housing fits, excessively tight
fits, out-of-round housings and a poor finish on the bearing seat.
How to Fix it
Follow proper mounting instructions and provide training to ensure all employees
understand the difference between a properly and improperly installed mounting.
4. Misalignment
Bent shafts, out-of-square shaft shoulders, out-of-square spacers, out-of-square clamping
nuts and improper installation due to loose fits can cause misalignment, which may result in
overheating and separator failure.
What to Look for
A wear path that is not parallel to the raceway edges of the non-rotating ring should be
noted.
How to Prevent it
Inspect shafts and housings for runout of shoulders and bearing seats, and use precision-
grade locknuts.
5. False Brinelling

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Rapid movement of the balls in a raceway while equipment is idle wears away at the
lubrication. In addition, a lack of rotation in the bearing does not allow fresh lubricant to
return to the spot. Both of these conditions result in false brinelling.
What to Look for
You may see linear wear marks in the axial direction at the rolling-element pitch or no raised
edges as opposed to marks due to incorrect mounting.
How to Fix it
Eliminate or absorb external vibration that could cause the balls to move. Also, be sure to
use lubricants containing anti-wear additives.
6. Corrosion
Moisture, acid, low-quality or broken-down grease, poor wrappings and condensation from
excessive temperature reversals can cause corrosion that is abrasive to the finely finished
surfaces of ball and roller bearings.
What to Look for
Look for red and brown stains or deposits on rolling elements, raceways or cages, as well as
increased vibration followed by wear, an increase in radial clearance or loss of the preload.
How to Fix it
Divert corrosive fluids away from bearing areas. Select integrally sealed bearings and
consider external seals for particularly hostile environments. Using the proper bearing
material, such as stainless steel, can help if you cannot avoid a corrosive environment.
7. Electrical Damage (Fluting)
Constant passage of alternating or direct current, even with low currents, can lead to
electrical damage.
What to Look for
Brownish marks may be observed parallel to the axis on a large part of the raceway or
covering the entire raceway circumference.
How to Fix it
Prevent electrical currents from flowing through the bearing by grounding or using insulated
bearings.
8. Fatigue (Spalling)
Spalling is often the result of overloading, an excessive preload, tight inner-ring fits and
using the bearing beyond its calculated fatigue life.
What to Look for
Fatigue can be indicated by the fracture of running surfaces and subsequent removal of
small, discrete particles of material from the inner ring, outer ring or rolling elements.
Spalling is progressive and will spread with continued operation. It is always accompanied
by a noticeable increase in vibration and noise.

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How to Fix it
Replace the bearing and/or consider a redesign that uses a bearing with greater calculated
fatigue life, internal clearances, and proper shaft and housing recommendations.
9. Overheating
Overheating is generally the result of excessive operating temperatures and improper
lubrication. High temperatures can cause grease to bleed (purge the oil), which reduces the
lubricant’s efficiency. In elevated temperature conditions, oxidation can lead to the loss of
lubricating oils from the grease, leaving a dry, crusty soap that can seize the bearing. Higher
temperatures also reduce the hardness of the metal, causing early failure.
What to Look for
Note any discoloration of the rings, rolling elements and cages. In extreme cases, the
bearing components will deform. Higher temperatures can also degrade or destroy the
lubricant.
How to Fix it
Thermal or overload controls, adequate heat paths and supplemental cooling are among the
best options to mitigate overheating.
10. Excessive Loads
Putting too much load on a bearing is another common cause of failure.
What to Look for
You may see heaving rolling-element wear paths, evidence of overheating and widespread
fatigue areas.
How to Fix it
Reduce the load or consider a redesign using a bearing with greater capacity.
11. Improper Storage and Handling
Improper storage exposes bearings to dampness and dust. Storing bearings in excessively
high temperatures can also degrade a grease’s shelf life, so always check with the grease
manufacturer for storage specifications. Handling bearings by opening boxes and tearing
wrappings prematurely can let in dirt and expose bearings to corrosive elements.
What to Look for
Watch for dampness and temperatures that can cause rust and/or uncovered bearings in a
storage area.
How to Fix it
Store bearings in a dry area at room temperature. Always cover bearings to keep them clean
while in storage and take them to the installation site before unwrapping.
12. Fit
A tight fit can be caused by excessive loading of the rolling element when interference fits
exceed the radial clearance at operating temperatures. Micro-motion between fitted parts
where the fits are too loose in relation to the acting forces may result in a loose fit.

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What to Look for
For a tight fit, look for a heavy rolling-element wear path in the bottom of the raceway,
overheating or an inner-ring axial crack. For a loose fit, note any fretting (generation of fine
metal particles), which leaves a distinctive brown color. Wear at the fitting surfaces can
cause noise and runout problems.
How to Fix it
Make sure a proper clearance is selected to avoid fit issues. Refer to the manufacturer’s
installation guide.
5.2 Failure in Hydraulic Cylinder – Causes and Cures
fig. Hydralic Cylinder
Hydraulic cylinders are basically mechanical actuators that provide unidirectional force
through a stroke. These cylinders are used in various industrial applications such as
manufacturing equipment, engineering vehicles, or civil engineering equipment. The
hydraulic cylinders may incur problems in a long run due to a variety of reasons are follows:
1. Damaged Chromed Rod
It is relatively easy to damage a chromed rod and extensive damage can be caused
by something as simple as contact with rocks or a chain, to something as severe as
violent environments and transportation. Alternatively, if we take a look at the
internal environment, there are a couple scenarios to be aware of. If an incorrect
seal package is being used in the gland, or if you or your team fail to notice poor
clearances between the inner diameter and the rod outer diameter on a previous
repair, new damage can occur and cause substantial damage to the chromed rod.
2. Piston Damage
If contaminants like dirt or dust infiltrate the system, scoring on the inner diameter
of the barrel can occur, causing extensive piston damage. It will also damage the
piston seals as well. One of the most efficient ways to prevent piston damage is
ensuring that the hydraulic oil is very clean.
3. Gland Seal Damage

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One of the major causes of gland seal damage is the occurrence of side loading on
the hydraulic cylinder rod. The angled and irregular pressure that comes from side
loading the cylinder creates an uneven distribution of force on the gland seal. This
force affects the mechanics, which creates the need to not only replace the gland
seal, but mechanical components as well.
4. Incorrect Seals Used in Prior Repair
If a company does not constantly re-calibrate their measuring tools, it is possible for
a seal that needs to be 6.0 mm, to end up being 6.2 mm or have a similar margin of
error. This margin of error can result in the failure of your hydraulic cylinder, which is
why working with an ISO certified company is so important. ISO certified companies
are required to calibrate their measuring tools, which ensures that all measurements
are exact and consistent every time.
5. Over Pressuring the Hydraulic Cylinder
Despite being more uncommon than the other types of failure, we thought it was
important to include over pressuring on our list. Over pressuring can occur in a
variety of ways and the most common form originates from a combination of valve
failures and released air. This causes pressure spikes, which in turn cause the barrel
to bulge, and the multi-stage cylinder rod to implode and the cylinder barrel to
explode. In severe cases, large collateral damage can occur, mainly damaging the
pump and valve motor.

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Conclusion
One of the primary objectives of the industries is to develop a well-knit personnel policy and
a comprehensive personnel programmer that will be result-oriented and to develop
organizational objectives. The Company has an exclusive Training and Development Centre
to take care of the training requirements of the officers and workmen as well as the newly
recruited Management Trainees etc. The training initiative includes special need-based
Programs and orientation programs catering to the requirements of various departments of
the company.
We had taken the project MUDGUN preparation in which we were associated in the repair
work of the MUDGUN ASSEMBLY in MARS 2 .The mudgun is used in Blast furnace for
opening and closing of the tap hole situated just above the hearth of Blast furnace for the
flow of liquid metal for further processing and it also used to tap the hole to again liquefy
the solid iron fine to the liquid metal. As we all know the Blast furnace is the Heart of any of
the steel plant, and for the continuous process of it the mudgun should be highly efficient.
MARS-2 repair the mudgun by re-claiming the old parts and adding some of new part we
thoroughly studied and practically worked on the mudgun about its parts, its assembly, its
function and its application.
During the course of project work we gain so much theoretical knowledge as well as
practical knowledge. We have experienced a wonderful practical work experience on actual
work field. We have acquired lots of skill which will beneficial to us for future.
The training at BHILAI STEEL PLANT was very helpful. It has improved our theoretical
concepts of material making and production. Protection of various apparatus was a great
thing. We have observed many machining processes like grinding, turning, cutting, arc
welding & oxy-acetylene cutting as well as the hydraulic machine.
We thank to BHILAI STEEL PLANT for providing us this great opportunity and also thanks to
machine shop MARS 2 for guiding and helping us to perform this project.

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REFERENCES:
 Books:
i. Shigley’s Mechanical Engineering Design 9th Edition by Richard G. Budyas and
J. Keith Nisbett.
ii. Degarmo’s Material and Processes in Manufacturing by J.T. Black, Ronald and
Kohser.
iii. Machine Design by V. B. Bhandari.
iv. Introduction to Physical Metallurgy by Sidney H Avner.
 Websites:
i. www.wikipedia.org
ii. www.skf.com
iii. www.concastmachine.com
iv. www.steel.org
v. www.steeluniversity.org
vi. www.metalpass.com
vii. www.gangsteel.com
viii. www.wikianswers.com
ix. www.sail-Bhilaisteel.com
x. www.sail.co.in