Problem: A secondary cleaner may be less effective if the belt has low tension; is not flattened as it crosses the cleaning blades; or if the belt is flapping in the area where the cleaner is installed. With low tension, the cleaner blades cannot be correctly tensioned for blade-to-belt contact. If the belt is not flat, the cleaner blades will not make full contact across the belt's width. And if the belt is flapping, the cleaner blades can't do a consistent cleaning job. A hold-down roller is the solution. But there may be confusion or questions as to where the hold-down roller should be positioned in relation to the cleaner for best results.

Solution: Unfortunately, there is no "one answer" for adding a hold-down roller. Each cleaner installation must be evaluated on two factors: location of the cleaner on the conveyor and specific running characteristics of the conveyor. Three general guidelines will help you position the hold-down roller in the best location:

1. If the cleaner is installed within a 2-foot span behind the head pulley, snub pulley, or return roller, put the hold-down roller behind the cleaner (Fig. 1).

2. If the cleaner is located in front of a snub pulley or return roller, position the hold-down roller in front of the cleaner (Fig. 2).

3. If the cleaner is installed in a location by itself, the hold-down roller should be located in front of the cleaner (Fig. 3). In all cases, the hold-down roller should be about 6" to 8" from the spot where the cleaner makes contact with the belt.

Handy Hint: When in doubt, flatten it out. It will never hurt to flatten the belt. It makes the cleaner's job easier and more consistent. And it will maximize the cleaning performance.