Containment Tips * Dust Control * Suppression * Environmental Solutions * Industrial Construction

Dust control is critical in increasing production as well as reducing maintenance cost. Its importance ranges from improved productivity, due to less unscheduled downtime, to increased performance of equipment, reducing maintenance cost.

More importantly, but not necessarily considered, is the long-term effects fugitive dust and spillage has on the human element. Studies reflect significant savings in medical cost as well as workman compensation cost when effective dust control measures are in effect.

• Accomplish with the use of impact cradles and sealing cradles.
• Install said cradles with idlers (steel cans as specified by CEMA) at each end to minimize belt drag and reduce horsepower requirements, usually impact idlers are suggested, minimum CEMA C.
• Alternative is to use idlers either standard or impact at 8-12" centers, however it will not eliminate all sag but can be relatively effective.
• Belt support should cover actual impact/load area as well as a distance equal to three times the belt width from impact area to ensure proper sealing.

• Determine length, usually 4-5 times belt width, and also design such that the side chutes are easily replaced. One method is to flange side chutes just above the area required for skirting.
• Chute height minimum of 18” to help reduce velocities (if room permits higher is usually better), the use of dust curtains can assist with air velocity reductions (if room permits). The curtains can be made of various materials such as nylon strips or old belting slit at ½” increments. The purpose is to allow material to accumulate and then drop to the belt. The larger the slits the more likely build-up will occur do the less movement, where as narrower slits will create its own vibration (movement) to release the attached particulate back onto the belt. In addition the use of curtain, as stated, reduces the velocity of the air, thus allows dust collector or dust suppression system to be more effective as well as minimizing the particulate size for the collector or suppression to contend with. The collector can be a centralized unit or a self-contained single pick-up point unit.
• Chute width such as to allow proper skirting system, usually 3-4” on each side. There are number of variations of skirting available, the two piece Apron Seal™ is our recommended style.
• Install tailgate 24”- 48” long, 18”-24” in height to help prevent rear spillage and dusting, install with access door at top of unit to assist with clean-up for unexpected occurrences, also install deflection plate to prevent airborne product to reach back of tailgate.
• Minimize impact by use of deflector plates, rock boxes etc.
• Keep chutes in-line for proper loading, if not possible the use of deflectors, liners, baffles, shapers, screens, grizzly bars, horseshoe plates and training gates can assist with ensuring balanced loading pattern.
• Use of wearliner to help prevent product from spilling and assist with material containment. Said liner to start as close as 3/16" above belt (at back of chute beginning of wear plate) and increase to as much as ¾” –1” above belt (at exit point). This is to prevent material from being lodged between belt and wearliner.

• There are a variety of sealing systems available such as rubber, urethane and UHMW, all have advantages and disadvantages. It is important to review for each application.
• One recommendation is the dual seal, available in either rubber or urethane.
• Use clamps, which are easy to install and to replace, try to match clamp length with side chute length. Be cautious as to the durability for the specified application. Size of clamps should take tonnage and belt speed into consideration.

• Design should be such as to allow for multiple belt cleaners, this pertains to both installation and required future maintenance. If room does not allow for dual system, then place single belt cleaner such that it removes a majority of the carry back within the head chute, the secondary should be mounted in such a manner as the debris removed drops to an area accessible for easy clean-up outside the head chute area. Also install a push down roller above contact point of cleaner to belt to promote maximum contact between belt and blade.
• Design of chute back plate should be a minimum of 9" behind point of contact of secondary cleaner to allow for maximum flow ability of product removed top cover belt.
• Use of wing style tail pulley with straps to limit vibration, however drum pulley is preferred, thus eliminating said vibration.
• New style trackers should be considered if belt misalignment is present.
• Installation of V-Plow or Diagonal Plow to protect tail pulley from any unexpected debris which may have fallen onto the underside of belt and could damage said tail pulley.
• If necessary consider using liner to increase wear life as well as flow.
• Chute angle should be greater the angle of repose of said material.
• Though not specifically related to sealing of transfer point it is important to make sure the transition from the tail pulley to the transfer chute is such not to cause stress to belting. One rule is to allow transition to be two times bet width.
• Design with access cover which is easily sealed.
• Seal all open holes, especially at points where cleaners' mainframes exit chutes. One easy and economical method is to cut rubber piece to seal around mainframe and attach with silicon. Therefore, when it is easily removed and replaced when maintenance is required.
• With respect to containment, we are not limited to the above referenced recommendations. There are a number of recommendations not covered in this paper, which can be considered. The above is a guideline to follow and modify to your specific needs. However, by following above suggestions the use of dust collection and/or dust suppression will be greatly enhanced. The result will be improved performance of dust control systems as well as improved housekeeping.
• Each application must be reviewed and the equipment best suited should be installed prior to determining/installing/modifying the dust control system. With properly sealed transfer point and head chutes the cost of installing and operating the dust control system are significantly lowered, both from initial cost and operating cost.