• Check for proper clearance. When the hopper above is emptied, a suspended feeder should be able to swing freely for a minimum of 1 inch front to back and 1/2 inch side to side without contacting any solid structure.

• Look under the feeder deck for missing liner bolts. If there are bolts missing, it is usually an indication that the liners are worn below the bolt heads and likely need to be replaced.

• Inspect suspension springs. If collapsed, they must be replaced. A good rule of thumb is that, if the space between the coils is less than 1/32 of an inch, the coil spring should be replaced.

• Look over the cables during operation to see if they are stable. If any of the cables are whipping, it may be an indication that the loading is not distributed properly. All suspension points must share the loading equally. If one of the suspension points has become loose or experiences a spring failure, it will overload the remaining springs. If turnbuckles have been used, ensure that they are locked in place by pinning, double-nutting, or tack welding. Feeder vibration can loosen the turnbuckles if they are not properly locked.

• Study the condition of the safety cables on suspended units. Ensure that they are not in contact with the feeder when the feeder is loaded with material. A good way to prevent the safety cable from interfering with material on a belt is to run the cable through a flat piece of metal conduit that is slightly wider than the feeder pan to take the sag out of the cable.

• Inspect the inside of the feeder deck for signs of material buildup. This material will affect the operation of the feeder and should be removed to prevent damage to the feeder. If inspected on a regular basis, the operators will soon become aware of the changing moisture, temperature, or material sizes that will likely cause the buildup. If sticking is a constant problem, contact the manufacturer to discuss alternate liner materials.

• Pay attention to the sound of the feeder. Normally, there is noise from the material being fed, but when the feeder is running empty, you should be able to carry on a conversation without a problem. If there is excessive noise from the feeder, there is a potential problem. There may be a loose liner or connection springs. On an electromagnetic feeder, there may be a striking condition in the drive. Check the air gap of the feeder and make sure it is to the manufacturer’s specifications. Do not over compensate this air gap setting; if it is set too wide, the feeder will draw excessive amperage and cause fuse failures.

Following these basic guidelines during routine maintenance walk-through inspections can minimize feeder downtime and help find any issues before they become problems. When found early, issues can be resolved and corrected during scheduled shut downs. AM

Carla Phelps is product manager, vibratory feeders, for Jeffrey Rader Corp. She can be contacted at cphelps@jeffreyrader.com.