Multi stage Centrifugal Blowers as a positive pressure device:
Multi-stage technology is an oil free, quiet and simple low pressure (0-18 PSIG) gas/air compressor for flows up to 25000 cfm in a single machine. This technology has a flat performance curve offering variable flow at a constant pressure. The makes this technology perfect for aeration, VOC gas boosting, nitrogen recirculation, air knifes/blow off, fluidization, combustion gas, conveying, etc.
Multi stage Centrifugal Blowers as a vacuum device:
Multi-stage technology is an excellent oil free, quiet, and simple vacuum blower which can produce up to 17” hg vacuum with flows up to 25000 cfm. Applications include vacuum hold down, liquid extraction/drying, land fill gas extraction, vent gas boosting, vacuum conveying, process vacuum, etc. Cast iron construction and aluminum impellers make it well suited for explosive gas applications.
Multi stage Centrifugal Blowers as a vacuum devise for central Vacuum Systems:
Multi-stage technology offers a simple and quiet vacuum blower technology with variable flow and constant vacuum performance. This coupled with a high efficiency filter receiver offers industry an excellent central house cleaning vacuum system. Systems can be designed for 1 user or 25 users picking up flour to marbles or serving a process high velocity dust/waste pick up such as filling, grinding or machining operations. This type system is often qualified as low volume –high velocity system.
Fans are often qualified as high volume and low pressure devices for moving air/gas. The range of flow and pressure is very broad from 1-1,000,000 cfm and pressures from ounces to psig. There are many different types with most common being axial and centrifugal. Materials of construction are limitless with common designs in steel, alloys, and fiberglass. They fall under the typical pressures and vacuum capabilities of the multi-stage blowers however there is overlap in the performance windows of each technology. Fan applications are many and include ventilation, dust collection, gas boosting, combustion, blow off or airknife, etc.
Regenerative blower technology offers clean, simple and quiet low pressure (0-8 PSIG) air/gas compressor for flows from 0-600 cfm. The blower has an impeller mounted directly on the motor shaft with a cast aluminum housing including integral inlet/outlet manifold. This technology offers an economical solution for low air/gas flows with pressure/vacuum requirements above fans and below multistage technologies. It offers a much quieter solution to positive displacement lobe type blowers. They can be designed with excellent corrosion resistance and sealing designs to work in tough process conditions.
Pnuematic Transfer Basics
A pressure or vacuum pneumatic conveying system transfers dry, flowable, bulk solid material from one point to the other through a piping system using air and the motive force. The system usually consists of a blower/compressor, line charger which feeds the material into the convey line and a material separator. The line charger typically is either a rotary airlock, pressure tank, slide gate in vacuum, or FK screw pump or double dump valve. The air/material separator is a cyclone or baghouse type dust collection unit. Conveying systems can be dilute or dense phase or a mixed phase that is define by the material to air ratio as well as the terminal velocity of the material.
Air Pollution Control Device (bag houses/cartridge collectors/cyclones/scrubber):
Air pollution is often defined as a particulate, aerosol or gas phase pollutants or a mixture. Dry particulate can be removed from the air/gas stream by a baghouse or cartridge collector or cyclone. The baghouse uses a fabric filter media often in the form of a long tubular or envelope style bag. The cartridge collector is the same concept with the exception is uses most commonly a pleated filter which is made of cellulose or synthetic fiber media. The aerosols or gas phase pollutants can be removed from the airstream through scrubbing process which forces a scrubbing solution in contact with the air/gas stream. The chemical reaction eliminates, changes or neutralizes the contaminant. There are several other methods of removing gas phase contaminants as well including thermal treatment, carbon filtration and dry scrubbing and electro static precipitators.