In steel plants reheating furnaces are used in hot rolling mills to heat the steel stock (Billets, blooms or slabs) to temperatures of around 1200 deg C which is suitable for plastic deformation of steel and hence for rolling in the mill.

1. REHEATING FURNACE
Presented By:
Vikas Vishnuchandra Yadav
Kalyani Charitable Trust's
Late G. N. Sapkal College of Engineering
Department of Mechanical Engineering
PRESENTAION ON :

2. FURNACES
 Design and manufacture furnaces on
turn key basis for the following
industries
Rolling Mills
Forging Plants
Heat Treatment Centers
Wire Drawing Plants
Aluminum Plant
Steel Plants
 Guaranteed fuel consumption of as
low as 33 ltr/ton for billet reheating
furnaces

3. DESIGN METHODOLOGY
 Capacity Rating
 Material Handeling
 Hearth Loading
 Heat Loading & Zoning
 Automation levels
 Planning of Combustion System

4. CAPACITY RATING
 Depends on the size and mix of produce to be preheated.
 The material of the billets play an important part in
finalizing capacity.

5. MATERIAL HANDLING
 Reheating furnaces can be divided into the following
categories:
 Pusher Type
 Walking beam /Walking hearth
 Rotary hearth
 Considering the charge we plan the material handling

6. HEARTH LOADING
 Based on the type of furnace hearth loading is
determined , with the focus on
 heat transfer ,
 pattern of heating i.e Top Heating or Top and Bottom heating

7. HEAT LOADING AND
ZONING
 Considering the design and capacity of the furnace
different types and sizes of burners are recommended in
the different zones of the furnace.
 Types of Burners
 LAP Burners
 High Velocity/ Oxy Fuel

8. AUTOMATION IN THE FURNACE
 In order to achieve greater efficiency in the
furnace and further increase production and
reduce scale losses the following automation in
the furnace can be carried out:
 Temperature Control
 Pressure Control
 Air/Fuel or Oxygen/Fuel Ratio Control

9. OXY FUEL TECHNOLOGY
 Reduced Emissions
NOx emissions are reduced substantially with a oxy-fuel conversion.
 Improved Efficiency and Production
Improvement in fuel efficiency as compared with traditional air-fuel
furnaces. The energy savings partially offsets the cost of oxygen. There
scale formation also comes down to 0.3%
 Increased Furnace Refractory Life
Temperature homogeneity of the furnace increases thus minimizing the
chances of thermal shocks in the refractory
 Simplified Operation
With no recuperator, the furnace operation and maintenance are simplified

10. CFD OF FURNACE

11. RESULTS OF CFD
ANALYSIS

12. CASE STUDY
Revamping of Furnace at TATA SSL,
BOISAR

13. PROBLEMS FACED BY
SSL IN THE FURNACE
 High Fuel Consumption up to 47 ltr/ton
 Improper Soaking of the Billets
 High Power Consumption by the Mill
 Frequent break down of the Mill
 The Furnace was only producing 36 Ton against the
designed capacity of 45 ton

14. MODIFICATIONS
 Heat Load calculation were done and accordingly the
combustion equipment's were changed
 Burners
 Blowers
 Recuperators
 Air and Oil pipeline were redesigned and modified
accordingly.
 Complete refractory lining was done again
 Walls
 Roof
 Hearth
 Water Cooled skid

15. RESULTS ACHIEVED
 Increase in production by 16-25% from 36 tons/hr to 42-
45 tons/hr.
 Fuel consumption reduced by 23-30% from 47 ltrs/ton to
33-36 ltrs/ton.
 Electrical Power consumption reduced by about 8%.
 Reduction in breakdowns due to better quality heated
billets

16. FURNACE DESIGN
 Designed a Top and Bottom fired furnace with
water cooled skids and PID based control.
 The furnace is designed for firing Mixed Gas
(Blast Furnace Gas and Producer Gas). The gas
will be either enriched with Oxygen or
supplementary firing of furnace oil will be done.

17. ELEVATION OF THE
FURNACE

18. BURNERS
 Oil Burners
 Gas Burners
 Dual Firing Burning Systems
 High Velocity Burners
(OIL/GAS)
 Pilot Burner for Coke Oven
Gas/ LPG/NG
 Coke Oven & Blast Furnace
Burner

20. RECUPERATORS
 Recuperators with flue temperatures of
up to 950oC
 Preheat temperature of combustion air
as high as 450oC
 Guaranteed savings of 15-20% and a
minimum life of 3 years for
Recuperators

21. THANK YOU!
“ Adopt eco-friendly technologies”