Pulse Jet Pointers
Vol. 3, No. 3

We have known a few optimists in our day who made no provision for the discharge of collected dust from the dust collector — thinking, perhaps, that they could move on to another place of employment before the problem sought resolution! For all you pessimists and realists, here are some considerations for successful dust removal:

1. What is the differential pressure between the hopper and atmosphere? Quiescence is essential in the hopper area. Any updraft due to leakage from the discharge device will disturb the dust, causing it to rise back to the collection area, and eventually plug the collector or cause carryover.
2. Can the process be shut down, or must the hopper be emptied while dust collection continues?
3. How accessible is the hopper? Must the valve be automated or can it be manually controlled?
4. What is the nature of the dust itself — abrasive, sticky, explosive, fluffy, toxic? Angle of repose (what slope it will slide down by gravity)?
5. What is the bulk density of the dust, and the rate at which it is generated?

Example #1
A dust collector in a metalworking shop, serving a few nearby operations, a fan creating only a few inches static pressure (water gauge), production schedules that can be suspended long enough to shut down the fan, easy access to the hopper for operation of the valve, dust that is not hard to handle with a bulk density and rate of generation within the capacity of the hopper for once a day servicing. The answer — an SBM manual slide gate (see photo).

Example #2
A pneumatic conveying system operating at six inches of mercury, no shutdown allowed during production, hopper not accessible for manual control of the valve, dust in the "difficult" category, and generated at the rate of hundreds of pounds per hour. The answer — a Rotor Rotary Airlock (see photo).

Slide valves are cast aluminum, carbon steel or stainless. They can be operated manually, or by chain wheel, rack & pinion, or air cylinders. They are designed to seal against almost any pressure experienced in dust collection applications, and have slide mechanisms that do not jam with dust. Rotary Airlocks, sometimes called "star valves," are available in various combinations of rotor and body in cast aluminum, cast iron, carbon steel or stainless. Tungsten carbide coatings for wear are also available. Produced in a variety of configurations with tapered rotor, offset construction, and heavy duty components, they have outboard bearings and triple packing rings with the option of an air purged lantern ring. Flanges are drilled for any specified bolt pattern, square or round. The drives are OSHA guarded, and motors are furnished to any specification. We also offer ni-hard pipe bends with replaceable wear plates and various types of diverter valves.

The answer —Bin Activators. These clever devices combat hopper bridges, clinging and ratholing problems. Equipped with an infinitely variable customer-programmed pulse timer, they provide groups of pulses at rates determined by field conditions. These units are stocked for immediate delivery.

· Home · Products · Typical Projects · Parts · Company History · FAQ ·  Customer Service ·  Contact Us · Site Map

Since 1921, Industrial Dust Control, Ventilation and Process Equipment

 Copyright © 2000-2007. Beckert & Hiester Inc.