How to Install Conveyor Belt?

The relative position of the top and bottom covers or surfaces of the belt should be considered when positioning the roll for threading. Once the roll of belting has been transported to the point of installation, it should be mounted on a suitable shaft for unrolling and threading onto the conveyor. Conveyor belting is normally rolled at the factory with the carrying side out.

Consequently, in mounting the roll, the belt must lead off the top of the roll if it is being pulled onto the troughing idlers or carrying idlers, but off the bottom of the roll if it is being pulled onto the return idlers. When pulling the belt onto the conveyor, the roll will turn opposite the direction indicated by the arrows on the crate. Fig. 1 illustrates a suitable method of mounting, as well as leading off the top of the roll for pulling onto the troughing rollers.

Fig. 1

In some cases, such as in mines where headroom does not permit maneuvering a roll, the belt may have to be pulled off the roll and reefed (Fig. 2). Extreme care should be exercised to see that the loops have large bends to avoid kinking or placing undue strain on the belt, and no weight should ever be placed on the belt when it is in this position. Ideally, supports should be placed at each end where the bends occur.

Fig. 2

A third method of handling the roll, where headroom for mounting on a horizontal shaft is lacking, is mounting on a turntable with a vertical spindle. The belt must make a 90-degree twist as it comes off the turntable. This method is sometimes used underground, with the turntable mounted on wheels or skids for transporting the roll of belt as it lies on its side, as well as for unrolling it at the final location.

If the belt is for replacement, the new roll can be set up as previously indicated. The old belt is clamped off and cut, and the new belt is spliced to the leading end of the old belt by using approximately one-half the usual number of plate-type fasteners. The trailing end of the old belt is hooked to a truck, tractor, mine locomotive or other means of providing traction. The conveyor drive motor is used to pull on the new belt while the towing device drags the old belt away and at the same time provides sufficient slack side tension for the conveyor drive pulley. In all cases, care should be exercised to ensure the carrying side of the conveyor is placed upward if pulling onto the top run, or downward if pulling onto the return run.

For a new conveyor installation having little or no slope, a rope or cable should be attached to a clamp at the belt end. In clamping to the end of the belt for pulling it on the conveyor, it is not sufficient to cut a hole through the belt or ears into its corners for tying on a rope. A clamp should be made to distribute the pull applied to the end across its full width.

Since the clamp must pass through places of low clearance, it usually is made of two pieces of 1/4-inch to 1/2-inch plate approximately equal to the belt width and 4 inches long. One piece is placed against each surface of the belt at the end, and bolts are placed through both plates at about 6-inch intervals and 2 inches back from the belt end. The rope is then attached to this clamp with a shackle or by welding an eye to one of the plates. The belt roll has been handled as previously described. The rope or cable is then threaded over the conveyor and attached to a towing device to pull the belt onto the conveyor.

Fig. 3

For installations with a relatively high degree of slope (12 degrees or more), the method of handling is slightly different. The roll of belt is set up as previously described. It is often found most convenient to place it at or near the head pulley, since this generally is the most accessible. Assuming the conveyor is sufficiently long to require more than one splice, the conveyor side and the return sides are threaded on separately. Care must be taken to see that conveyor side or heavier cover is up on the carrying side and down on the return run.

As the belt is fed on, the tension at the roll tends to build up due to the weight of the belt on the slope. For this reason, some method of braking is required. Customary practice is to use a belt clamp, mounted on the conveyor structure, through which the belt is threaded. Where the slope is very long, additional clamps should be spaced approximately 1000 feet apart. Where more than one clamp is used, workers are stationed at each clamp to loosen and tighten the clamps as the belt is fed onto the conveyor. Care must be exercised that the belt does not run away. As a roll runs out, another is spliced on and then fed onto the conveyor.

If the conveyor side and the return side have been fed on separately, the final splice is best made at the bottom of the slope where the ends of the belt meet, since a much lower splicing tension will serve at this point. Making the final splice at the top of the slope is entirely possible but requires proper splicing tension.

When pulling the belt onto the system, station personnel at key points along the conveyor to help avoid the belt from hanging up on the structure resulting in belt damage. Pull the belt ends until they overlap the required splicing length.

Fig. 4

To prevent the belt roll from over-running at the let-off, a braking device is often needed (Fig. 4).

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