Pipe Conveyor FAQ

  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 conveys petroleum coke at approximately 300 tph in a 12” diameter pipe. Krupp   Robius, 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. Currently technology enables us to engineer pipe conveyors to deflect through a horizontal angle of 90°. An example of this is the Indo Gulf pipe conveyor 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 reduced 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 larger 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 Richards 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 rather 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 compared. 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 conveyor has the following generic advantages:
    1. The belt encloses the material on the carry-side. This eliminates spillage and protects the environment and product conveyed.
    2. On the return-side the belt encloses the dirty side and eliminates spillage along the conveyor. This is advantageous environmentally and reduces on-going clean-up costs.
    3. 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.
    4. Material can be conveyed along the top and bottom strands simultaneously, along the same route, without spillage or contamination of the product.
    5. The pipe conveyor is cost-effective. In some instances the pipe conveyor has a lower total capital cost than multiple troughed conveyors with transfer buildings, etc. 

  7. Q: Is the pipe conveyor belt similar to the troughed conveyor 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 worldwide?
    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:
    1. Ensuring straight belt splices.
    2. Ensuring the structure and idlers are correctly aligned.
    3. Correctly manufactured belt i.e. equal tension across full belt width and the carcass is straight.
      1. Correct spacing of idlers.
      2. Employing training idlers.
      3. Sufficient belt tension.

      Note: It is usually acceptable for the overlap to rotate approximately 20°to either side of the top-dead-center.

  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 conveyor?
    A: Yes, provided these loading points are not located on a curve and there is adequate 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 conveyors 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 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