The document discusses pipe conveyors and compares them to traditional troughed conveyors. Some key points: - Pipe conveyors can negotiate tighter curves than troughed belts, require fewer transfer points, and have less spillage, but require more power due to additional idlers. - Carrying capacity is higher for pipe conveyors of the same width compared to troughed belts, but pipe conveyors require wider belts. - Idler spacing must be closer for pipe conveyors to maintain the pipe shape, significantly increasing idler and bracket costs. - Proper belt training is important for pipe conveyors to prevent damage and leaks, as the belt forms a complete pipe around material.

1. ISSN 01739980 · Volume 35 · 4 /2015
Cover Story: Projects with Pipe Conveyors p. 20
A Hopper Flow Solution for a Concrete Plant p. 14
How to Convey Hot Stuff p. 28
www.bulk-solids-handling.com
CKIT Conveyor Engineers
Picture:©CKITConveyorEngineers(Pty.)Ltd.

2. Contents
4
4 /2015
Pipe conveyors are often perceived to be expensive
and difficult to maintain. The article shows that pipe
conveyors are not only viable but more effective then
troughed belts in many respects. 20
Waste material is difficult to weigh due to
light loading, sudden changes in bulk density of
the material, and other material handling issues
that arise. 40
Keeping the environment safe from impacts of stored
copper ores as well as minimising material losses were
the main reasons for building two storage domes at a
newly developed mine in Northern Chile. 35
Service News
Editorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Company and Personal News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Market Watch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Advertiser Index/Imprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Events
Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Technical Articles
Conveying Transportation
Lyn Bates
A Fundamental Approach to Belt Feeder Loads –
How to assess loads on Feeders, (practically) . . . . . . . . . . . . . . . . 14
Sachin Ramjee, Phil Staples
Pipe Conveyors for Infrastructure Projects –
Innovative Solution for Conveyor Systems . . . . . . . . . . . . . . . . . . . 20
Norbert Kleinerüschkamp
How to Convey Hot Stuff –
Steel Apron Conveyor for Transport of hot Bulk Solids . . . . . 28
Product News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Storage Handling
Down the Rathole –
A Hopper Flow Solution for a Concrete Plant . . . . . . . . . . . . . . . . 32
Victor Cavazos
Valuables covered for Environmental Protection –
Domes over the 7th
largest Copper and Moly Development . 35
Product News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Automation Drives
Matt Morrissey
From Garbage to Gold – Belt Scale Applications
made easy even in demanding Environments . . . . . . . . . . . . . . . . 40
Product News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Science Technology
Gabriel Fedorko, et al.
Dynamic Damage of Rubber-Textile Belts in
Pipe Conveyor Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

3. 20 bulk solids handling · No. 4 · 2015
Conveying Transportation
Pipe conveyors were initially designed
by a Japanese conveyor company in
the late 1970’s as an innovative solu-
tion to enclosed conveyor system solu-
tions. In 1990 the bulk material industry
received approval to freely use this tech-
nology. This allowed for large leaps in
technology, making pipe conveyors a
more effective way of conveying bulk ma-
terial. However this did not last as pipe
conveyors are perceived to be more ex-
pensive and difficult to maintain. In the
following sections it will be shown that
pipe conveyor solutions are not only via-
ble but more effective then troughed
belts in many respects.
Description of Mechanisms
Pipe conveyors are simply troughed con-
veyors which form an enclosed pipe. This
is achieved by increasing transition idler
angles and eventually six roll idler configu-
rations on a specified diameter. The tran-
sition distance at the tail and head end of
the conveyor is responsible for gradually
shaping the belt. This change in shape
from trough to pipe has had far reaching
effects on the design and equipment used
in bulk material conveyance.
Pipe Conveyors: Advantages
Pipe conveyors provide effective solutions
for a variety of problems faced in the in-
dustry, this includes
Pipe Conveyors
for Infrastructure Projects
Innovative Solution for Conveyor Systems
Ckit was approached by a customer to prepare a research paper on the advancements
of conveyor design and manufacturing. This report focuses on the successes, shortfalls
and solutions to pipe conveyor design, manufacturing and related. This article outlines
the theory, design, operating and manufacturing procedures for pipe conveyors.
SACHIN RAMJEE, PHIL STAPLES *
slip is reduced by the idler configura-
tion.
ƒƒ Greater rate of elevation is obtained
due to the increased contact between
belt and material.
ƒƒ Has better belt edge damage control,
due to improved belt training.
ƒƒ Weather resistance to wind and rain is
improved as the material is enclosed,
therefore gantry does not require covers.
ƒƒ Ecologically/environmentally friendly as
it is able to pass around sensitive areas
and negotiate remote terrain.
Picture:©CKitEngineering
ƒƒ Spillage free transportation of material
is obtained due to the enclosed belt.
ƒƒ Material build-up on idlers is reduced,
decreasing maintenance, as no material
is spilled during transit.
ƒƒ Pipe conveyors fit into narrow areas
and save space in congested areas. This
is possible due to a circular belt profile,
allowing the gantry width to be re-
duced.
ƒƒ Can negotiate tight horizontal and ver-
tical curves because the material is en-
closed within the pipe and cross belt
* S. RAMJEE , P. STAPLES
CKit Engineering (Pty) Ltd., Bedfordview 2008,
Republic of South Africa
Tel. +27 114527347, E-Mail: info@conveyorkit.com
Fig. 1: Pipe conveyor installation

4. 21bulk solids handling · No. 4 · 2015
Conveying Transportation
Fig. 2: Pipe conveyor forming
Disadvantages
The formation of the pipe conveyor does
not come without its disadvantages; how-
ever these often become negligible in light
of the large improvements to that the
pipe provides.
ƒƒ Pipe conveyors have larger power re-
quirements due to the large additional
amount of idlers
Fig. 4: Pipe conveyor concept
Fig. 3: Gantry- and Trestle-type conveyor structures
ƒƒ Larger belt widths are required to form
a pipe diameter capable of conveying
the same material as a troughed con-
veyor (considering both belts run at the
same speed)
ƒƒ Overloading and over-sized particles are
more likely to cause problems in the sys-
tem. This is because of the limited space
available within the closed pipe com-
pared to open troughs of standard sys-
tems.
ƒƒ Due to the completely enclosed ar-
rangement of the belt and idlers main-
tenance and removal of the belt is more
difficult.
Comparison between Pipe
and Troughed Conveyors
Carry Capacity
Table 1 shows the carrying capacity of
pipe and conventional conveyors. This ex-
ample allows for 70% fill factor and a belt
speed of 4 m/s for a material density of
1000 kg/m3
.
From this we find that the belt width of
pipe conveyors is far larger than that of
conventional conveyors for the same ton-
nage. This must be carefully considered
when choosing between pipe and
troughed conveyors because of the cost of
belting.
Route Layout
From the analysis in Fig. 4 we find that the
pipe conveyor allows for fewer transfer
points because it is capable of negotiating
tighter curves and inclines. The increase in
horizontal and vertical curves further in-
creases the power requirement. Conven-
tional conveyors will require large inclines
to feed into the following transfer increas-
ing the power requirements. From this we
see that depending on the route, length
Table 1: Conveyor Capacity Comparison
Belt Width
[mm]
Pipe Diameter
[mm]
Capacity Pipe
Conveyor [t]
Equivalent Belt
Conveyor [t]
1000 250 500 1300
1200 300 720 1900
1400 350 1000 2600
1600 400 1300 3500
1800 450 1600 4450
2000 500 2000 5500
2400 600 2850 8400

5. 22 bulk solids handling · No. 4 · 2015
Conveying Transportation
and curves either pipe or conventional
conveyors will be used.
Power Requirements
The basic power comparison (Table 2) was
carried out for a conveyor running 2000 t/h
at 4 m/s. The route includes multiple hori-
zontal curves with 5000 m radius.
Fig. 5: Route comparison
ƒƒ The belt strength must be sufficient to
transmit the power across the span of
the conveyor.
ƒƒ The belt carcase must be able to sup-
port the material duty, conform to the
idler configuration when empty
(troughability) and allow for enough
flexibility to wrap around pulleys.
ƒƒ The quality of the belt cover must be
suitable to withstand the physical and
chemical effects of the material being
conveyed. This includes abrasion, tem-
perature of material and corrosive ef-
fects.
In order to calculate the power require-
ments and choose a suitable belt for the
conveyor; calculation of the belt tension is
required. Factors to be considered are
ƒƒ Friction factors of the system such as
belting material and pulley construc-
tion.
ƒƒ Material and belt mass per unit
length.
ƒƒ Conveyor profile with regards to ho­
rizontal and vertical curves.
ƒƒ Conveyor configuration with regards
to idler spacing and pulley configura-
tion.
Equations are formulated to calculate
the effects of each of the above considera-
tions:
where
Table 2: Power Requirements
Pipe Conveyor
2000 mm wide
1600 KW
Belt Conveyor
1200 mm wide
1200 KW
Table 5: Idler number
Pipe
Conveyor
2m spacing 5000
Belt
Conveyor
3m carry spacing 1664
6m return spacing 832
Table 3: Belt weight
Pipe Conveyor 45 Kg
Belt Conveyor 30 Kg
Table 4: Belt weight
Pipe Conveyor
2000mm wide
ST 1200
Belt Conveyor
1200mm wide
ST 2000
We expect the power consumption of
the pipe conveyor to be higher due to
added idler friction and large belt mass.
This does not make the troughed convey-
or a better solution; it simply shows the
difference in supplied power.
Structural Components
Above we noticed that to carry a similar
amount of material on a pipe required a
wider belt than that of conventional con-
veyors (Table 3). Below we see that the
required belt grade/rating for pipe con-
veyors are lower than that of the conven-
tional conveyor (Table 4). The tension
within the belt in order to pull the belt is
distributed across the belt, for this reason
the rating of the belt is lower for pipe con-
veyors because a wider belt it used.
Idler spacing is to be kept lower for pipe
conveyors in order to maintain the shape
of the pipe. This drastically increases the
number of idlers and brackets (Table 5),
which in turn has significant effects on the
cost of the conveyor.
Pipe Conveyor Theory
Pipe Conveyor Calculations
Belt Tension
Belt tension calculation for pipe convey-
ors is carried out in the same fashion as
troughed conveyors. Two major proper-
ties of the belt to consider is what pro-
vides the tensile strength of the belt (rein-
forcement of a carcase) and the belt re-
sistance to surface damage (i.e. elastomer-
ic cover grade). Belt selection considera-
tions include:

6. 23bulk solids handling · No. 4 · 2015
Conveying Transportation
Fig. 9: Older idler panel design
where
where
Power Requirements
The power requirements for pipe convey-
ors are calculated in the same manner as
troughed conveyors. We find that for a
straight inclined conveyor the power re-
quirements for the troughed belt are low-
er than that of the pipe. The additional
power is as a result of forming the belt
and increased friction between the belt
and idler sets. When considering curved
profiles, power consumption increase as a
result of changing the horizontal direc-
tion of material within the pipe.
Power requirements increase with the
number of transfer points; this is due to
the increased power to raise the conveyor
to the required height for transfer to the
next conveyor. Pipe conveyors require
fewer transfers as they are capable of ne-
gotiating tighter curves (smaller radius).
For this reason pipe conveyors gain an ad-
vantage of lower power consumption
when conventional troughed conveyors
would require many transfer points.
Conveyor Profile
Due to the enclosed pipe profile and 6
idler support configurations, pipe convey-
ors are capable of negotiating tighter
curves, with a smaller radius. When tilting
the frame on horizontal curves, material is
safe within the pipe reducing spillage at
these points. This also has its shortfall in
Fig. 6: Pipe conveyor curve
Fig. 7: Pipe forming and opening equipment
Fig. 8: Issues with six idlers on two sides (left) and on one side (right)
that the greater change in di-
rection causes a larger ten-
sion in the belt and power re-
quirement of the drive.
A comparison of troughed
and pipe conveyor routes is
shown in the corresponding
section above.
Idler Design and
Mounting
The idler configuration main-
tains the shape of the belt and
provides support for the belt-
ing over the profile. The bot-

7. 24 bulk solids handling · No. 4 · 2015
Conveying Transportation
Fig. 10: Belt training (a( and b)) and idler adjustment for belt training (c)
tom three idlers support the load and the
top three to keep the pipe form. For this
reason, idler configuration for pipe convey-
ors has been the subject of many discus-
sions over the years. Major concerns are:
ƒƒ Large friction between the belt and id­
lers increases power demand and wear.
ƒƒ Belt training to reduce pipe rotation
which allowing leaks in the pipe.
ƒƒ Idler and support structure alignment to
ensure minimal belt wear and friction.
Idler configurations consist of two sets
of three idlers in a hexagonal shape. Origi-
nally Idlers were all placed on one side of
the support panel, this caused idler inter-
ference and belt edge wear. To ensure this
does not happen, Ckit proposed the new
Idler configurations which are discussed
in the last section.
Belt Training Procedure
Belt training is important to pipe convey-
ors in order to prevent belt fouling with
the structure, chute work etc. This will re-
sult in permanent damage to the structure
and belt. Furthermore belt alignment is
used to keep the overlap in the belt at the
vertical top of the pipe form. This is done
to reduce spillage, as seen in Fig. 9.
Belt training is to be carried out for
three conditions, no-load, partial-load
and full-load. Training of the belt is done
by one person to reduce redundancies
and duplication.
The testing procedure is as follows
1. Station personnel along the length of
the conveyor to monitor the pipe rota-
tion.
2. Station personnel at the head and tail
end to monitor the pipe forming
3. The belt overlap is monitored with ref-
erence to the structure , making sure it
does not rotate more than 20° clock-
wise or anti-clockwise
4. If the belt rotation is greater than 20°
belt training is required.
The procedure for belt training is as fol-
lows:
1. Training of the belt is carried out by one
person to reduce redundancies and du-
plication of idler adjustments.
2. Training the belt requires the responsi-
ble person to rotate and position the
bottom idler of the configuration.
3. Training of the belt begins at the tail end
of the conveyor.
4. First adjustment is to the tail pulley, then
loading and transition section, and along
the carry side to the head end pulley.
5. Once at the head-end section, training
follows the belt through the take-up,
drive and head pulley.
6. Training is complete once the return
belt has been adjusted.
Fig. 10: Tilted idler resistance
a) b) c)

8. 25bulk solids handling · No. 4 · 2015
Conveying Transportation
Fig. 11: Added tension due to curve
Effects of Idler Support Structure Alignment
Idler support structures have a large im-
pact on the running of pipe conveyors
and can be the difference between success
and failure of a project. Correct mounting
of the idlers result in lower power con-
sumption and less wear on equipment.
From experiences in India of poor erection
of idler support structures we find that
Ckit Contributions to Pipe
Conveyors
Idler Mounting
Ckit has developed idler brackets mount-
ing whereby one set of three idlers is on
the front of the bracket and one set of
three is at the back of the bracket. This
reduces belt pinching between idlers
which cause belt edge damage. This also
reduces the interference between idlers,
which often occurs when mounted on a
single side.
The mounting of the idlers has also
been modified to decrease its mass while
maintaining rigidity; this reduces the load
bearing pressure on the trestles. This re-
duction has a major effect on the trestle
and footprint design. The smaller frames
allow it to be easily mounted within the
triangular gantry area (Fig. 12).
Triangular Gantry
To reduce the mass of the gantry, the
cross-section was changed to a triangle,
this allowed for less steelwork with the
same rigidity (Fig. 13).
Maintenance Trolley
Ckit designed and developed self-pro-
pelled maintenance trolley has been a
revolutionary design for conveyor tech-
nology. It allows for maintenance person-
nel to easily perform inspections and
maintenance on damaged idlers and re-
lated structures.
The trolley is large enough to carry all
equipment and spares, making mainte-
nance quicker and therefore reducing
downtime. The trolley is driven via hy-
draulic motors and is supplied with a
power generator to carry out mainte-
nance where required. nFig. 12: New light weight idler panel design
Fig. 13: Triangular gantry construction Fig. 14: Maintenance trolley
further resistance is added through tilt re-
sistance (Tt). This model is currently being
analysed by our team in order to minimize
its effects. The model is based on the pre-
requisites presented in Fig. 10.
As material flows through horizontal
curves, we find that the change in direc-
tion of the material increases the required
power. This is based on the analysis ac-
cording to Fig. 11.

9. 26 bulk solids handling · No. 4 · 2015
Conveying Transportation
Appendix: Frequently asked Questions
1. Q: Can a pipe conveyor convey material vertically? A: No, the pipe conveyor can be inclined at up to 20% greater grades than a trough
belt conveyor; however, vertically conveying is not possible.
2. Q: What is the maximum length of a pipe conveyor? A: The longest pipe conveyor installed is approximately 5,2 km in length and con-
veys petroleum coke at approximately 300 tph in a 12 in (300 mm) diameter
pipe. Krupp Robins, Inc. in the USA supplied this conveyor. Conveyor Kit’s
longest pipe conveyor is a 450 mm diameter pipe with a conveying capacity of
1800 tph. The transport distance is 3,2 km. This conveyor is at Indo Gulf in
India. Current technology is making pipe conveyors of up to 10 km in length
feasible.
3. Q: Can a pipe conveyor negotiate a 90° bend? A: Yes. Currentlytechnology enables us to engineer pipe conveyors to deflect
through a horizontal angle of 90°. An example of this is the Indo Gulf pipe con-
veyor designed by Conveyor Kit. The layout of each specific installation must be
checked to ensure that a sharp bend can be accommodated.
4. Q: What is the maximum lump size, which can be handled
in a pipe conveyor?
A: The rule-of-thumb is that the pipe diameter should be four times the maximum
lump size. Depending on the percentage of larger lumps however, this can be re-
duced to three times maximum lump size. The largest diameter pipe conveyor
supplied by Conveyor Kit has been 450 mm. Pipe diameters of 500 mm and larg-
er are theoretically feasible.
5. Q: What is the belt speed of a pipe conveyor? A: The belt speed, pipe diameter, capacity, site conditions, material characteristics
and lump size are selected for each specific installation. The greatest belt speed
on a Conveyor Lit pipe is 4,2 m/s on a 900 m long, 2500 tph installation at Rich-
ards Bay, South Africa. Belt speeds of 6 m/s and more are possible but may not
be practical.
6. Q: What are the advantages of using a pipe conveyor rath-
er than a troughed conveyor?
A: Pipe conveyor technology has come far in the last 50 years or so and presently is
on par with trough conveyor technology. As such, these conveyors can be com-
pared. The choice of conveyor for any application should be weighed up against
the specific criteria and objectives of each customer and/or site. The pipe con-
veyor has the following generic advantages:
a. The belt encloses the material on the carry-side. This eliminates spillage and
protects the environment and product conveyed.
b. On the return-side the belt encloses the dirty side and eliminates spillage
along the conveyor. This is advantageous environmentally and reduces on-go-
ing clean-up costs.
c. The pip conveyor can negotiate tight horizontal and vertical curves thereby
eliminating transfer points and multiple troughed conveyors to perform the
same duty of one pipe conveyor.
d. Material can be conveyed along the top and bottom strands simultaneously,
along the same route, without spillage or contamination of the product.
e. The pipe conveyor is cost-effective. In some instances the pipe conveyor has a
lower total capital cost than multiple troughed conveyors with transfer build-
ings, etc.
7. Q: Is the pipe conveyor belt similar to the troughed con-
veyor belt?
A: The required flexibility in a pipe conveyor belt to form and maintain the tubular
shape is partially dependent on the belt design. The pipe conveyor belt is thus
different to the troughed conveyor belting. There are a number of suppliers of
pipe conveyor belting worldwide and pipe conveyor OEM’s often recommend
specific suppliers for spare purposes.
8. Q: How many suppliers of pipe conveyors are there world-
wide?
A: There are approximately six major suppliers of pipe conveyors worldwide, with
substantial reference installation.
9. Q: How is the overlap of the carry-side belt prevented
from rotating in the structure?
A: The overlap is maintained a the top segment of the structure by:
a. Ensuring straight belt splices.
b. Ensuring the structure and idlers are correctly aligned.
c. Correctly manufactured belt i.e. equal tension across full belt width and the
carcass is straight.

10. 27bulk solids handling · No. 4 · 2015
Conveying Transportation
i. Correct spacing of idlers.
ii. Employing training idlers.
iii. Sufficient belt tension.
Note: It is usually acceptable for the overlap to rotate approximately 20°to either
side of the top-dead-centre.
10. Q: What would be the cause of the belt opening up along
the closed section?
A: Inadequate belt tension, overfilling, stiff belt (new?), incorrect belt selection or
idler spacing too large.
11. Q: Why does the return-side belt form a smaller diameter
after the first two months, and no longer touches the
upper rollers? Is this serious?
A: The overlap of the return-belt is at the bottom of the tubular belt. The weight of
the belt itself tends to cause the width of the overlap to increase as one belt
edge “wraps” inside the other, thereby reducing the pipe diameter marginally.
This phenomenon is “normal” and begins to occur within a month or so of hot
commissioning, as the belt’s rigidity reduces with service. This does not usually
impede reliability or the operation of the conveyor.
12. Q: How frequently should idlers be spaced? A: The pitch or the carrying and return idlers can vary along a conveyor and may
be different for each conveyor. Typical idler pitch can vary from 0,5 m to 2 m.
13. Q: Can multiple loading points be used on a pipe convey-
or?
A: Yes, provided these loading points are not located on a curve and there is ade-
quate room to open and re-close the belt.
14. Q: What criteria are important for idlers? A: The total rolling resistance is greater for pipe conveyors than for troughed con-
veyors due to the greater number of idlers employed. Thus it is important that
roller do not have too high resistance and breakaway force. Roll diameter varies
from typical 80 mm to 150 mm depending on the duty, belt speed and locally
available standard roll diameters. Conveyor Kit generally uses 14 mm diameter
rollers or greater.
15. Q: The edges of our belt are chipped and pieces have
been ripped out of the edges. What causes this and
how can this be eliminated? *
A: Some pipe conveyors employ all six rollers on the same side of each panel. In
this case the roll face length is selected to enable the rolls to butt-up against
each other. It is possible that your belt edge is being trapped between the two
rolls and is rubbing against the panel, damaging the belt.
Conveyor Kit generally uses 3 idlers on each side of the panel and in doing so, the
roll length overlaps so that it is impossible for the belt to rub on the panel.
* Please see also the article by Fedorko et al on page 44.