Air-Cure Inc. RF Dust Control Filter

Air-Cure Inc. is the leader in complete dust collection systems. We manufacture and supply dust collection systems and equipment, and specialize in PRB coal both at mines and utilities. View installation pictures of RF Filter applications in our Image Gallery. (3MB PDF)

Air-Cure has a core group of engineers that have been working together in dust control for over 25 years and have over 700 installations on PRB coal dust. Air-Cure engineers have invented and built many baffle and dust containment enclosures for many processes from Rotary Car Dumps, trestle dumps, rotary breakers, batch load-outs, and zipper ducts. We are the leading supplier of dust control equipment for the mines in the Powder River Basin and for the utilities on PRB coal.

All present dust collection equipment at Powder River Company's Peabody North Antelope and Rochelle Mines have been designed and provided by Air-Cure and Air-Cure's predecessor companies. We have worked with the Powder River Coal Company for 18 years. Our team of engineers are currently assisting in solving batch load-outs, bin ventilation, and dusting problems with Powder River Coal personnel.

Designed for a variety of applications:
Light, medium & heavy dust concentrations.
Low bulk density materials.
Dust from wood, grain, glass, clay, coal & carbon black.
Metallurgical fumes.
Abrasive materials like glass cullet, taconite & soda ash.
Sticky substances like sugar or starch.

RF filter can cut power costs by as much as 75%. The cleaning system of this efficient filter is powered by an air pump rather than the conventional fan. The result is the RF filter demands only 25% of the power needed by similar filters.

Of course, the RF filter cuts more than power costs. It goes on to provide substantial maintenance savings, lower installed costs and economical operating costs.

Not only recognized by its users for cost savings, but by organizations in the fields of energy conservation and air pollution control. This filter received two first place awards for reduction of energy consumption in two national design and technology competitions.

The Air-Cure RF filter is the most cost efficient filter available; and it's simple.

Unique Design for Unmatched efficiency
Because of its design features, the RF filter is accepted and respected in a variety of industries where demanding performance is the norm. It meets and exceeds the most stringent EPA codes.

The key to the RF filter's outstanding efficiency is its unique jet tube cleaning system. The RF filter maintains a consistently high level of filter porosity without wasteful over-cleaning of the filter tubes and without blocking off any one tube for more than a fraction of a second.

Most filters are not as efficient in cleaning each tube, requiring higher horsepower, consuming more energy and building higher energy costs. By contrast, the RF filter cleaning system fires carefully calibrated pulse of air, which cleans each tube often enough, to maintain constant porosity with unmatched efficiency. At the top of the filter is a traveling plenum, which delivers a quick pulse of counter-flow air to the tubes as it moves around the filter chamber. The jet of air creates a positive snapping action of the filter tube, which shakes loose entrapped dust particles. The volume and pressure of the airbursts have been carefully computed to provide maximum shock action with enough backwash to carry the particulates away from the cleaned tube. The tubes have an oval design, which promotes better snapping, release and flushing of the entrained dust. Random sequence eliminates dust redeposition to adjacent, previously cleaned tubes. No adjacent bags are cleaned at the same time. The system is simple, effective with a minimum of moving parts to keep maintenance costs under control.

The RF filter's cyclonic design
promotes even more efficiency.

Dust laden air enters the RF filter on a tangent to the filter chamber and a circular baffle keeps the incoming air from moving directly to the filter tubes. Instead, it is spun around the lower portion of the filter; a cyclonic action that strips the heavier dust particles from the moving air and drops them directly into the hopper. Next, the air straightener vanes redirect the incoming air to a uniform upward velocity. As a result, the pre-cleaned air carries the remaining dust up through the felted filter tubes depositing the dust over the maximum surface area for maximum efficiency.

High Energy Pulse Jet (RF Filter)
vs. Standard Pulse Jet

Air-Cure's "RF" filter cleaning system creates a high-pressure wave using a high volume of air at lower pressure (71/2 psi). This fills the full length of the tube when injected into the filter tube through a mean orifice of 1/2"x 3" in area. Resulting in more cake release, more flexing of the media and more energy to overcome the normal pressure drop across the tube - and less electrical power cost to you. Whereas, the standard pulse jet using 80 to 100 psi cleaning air injects high pressure air through an 1/8" orifice to a filter tube of 10' to 14' in length. The result is a short burst of air enters the tube (less volume) with insufficient force to adequately flex the filter media for proper tube cleaning - and at higher electrical power cost to you. The standard pulse jet concentrates the cleaning action at the top of the filter tube rather than the full length of the filter tube.

No Adjacent Bags Cleaned at the Same Time
The exclusive pulsing technique in the bag cleaning system prevents re-entrainment of dust particles on a previously cleaned bag. No adjacent or neighboring bag is cleaned in sequence; time delay prevents redeposition of dust. This is accomplished without complex indexing electronics.

At the same time, this results in a more balanced environment within the filter's cleaning section, a more uniform airflow and less turbulence.

This means more efficient, thorough bag cleaning, longer bag life and more effective dust collection.

No other dust filter design can provide you with this patented feature.

Filter Bag Cleaning System
Cleaning air action is created by an unbalanced pressure across the two diaphragm valves - a secondary and primary (larger).
Click to view the closed and open positions of both diaphragms. Red positions indicate both are open, dumping cleaning air into a rotary manifold. Blue positions indicate both diaphragms are closed and sealed. The solenoid valve (atop diaphragm valve) is energized by a pre-set timer. In milliseconds it releases air pressure on the backside of the secondary diaphragm, which in turn, unbalances the air pressure on the primary diaphragm - allowing high volume air to enter the rotary manifold's plenum and exit through nozzles for filter bag cleaning.

Cleaning air supply originates from an air reservoir tank. This tank receives its air from a rotary air pump operating at approximately 7.5 psi.

Air-Cure RF filters cut
operating costs to simple minimum.

The filters begin their cost-cutting operation with a rotary air pump, which operates at approximately 71/2 psi rather than a lower pressure fan or a high pressure piston pump.

The RF filter cleaning system is an electromechanical. When the air reservoir reaches approximately 71/2 psi, a pressure or time derived pulse energizes the solenoid valve. The solenoid valve opens a diaphragm valve feeding air to the rotary manifold plenum and nozzles. The fact that the air pump is driven by a lower horsepower motor than those demanded by high pressure compressors or fans drops your energy consumption to 50% or less of that drawn by competitive units.

It's the amount of filter cloth area that determines a filter's capacity and efficiency. The more area put to work the more efficient the filter. Air-Cure's RF filter features a non-aligned arrangement of the filter tubes to provide more tubes and more filter cloth in a given area. In addition, the RF's unique cyclonic design with inlet deflector baffles and air straightener vanes permit the maximum exposure of incoming, dust-laden air to the filter media.

Maximum filter area, maximum exposure of available area, coupled with the most efficient, most effective cleaning method available anywhere results in the most cost efficient dust filter in the industry.

Proven performance throughout the industry.
The design of the RF filter is simple; to keep maintenance simple and maintenance costs low. To start, it has fewer moving parts, only a single solenoid and no mechanical indexing valves. The result: fewer components that demand routine maintenance, fewer opportunities for something to go wrong.

Furthermore, the RF filter is designed to make maintenance as convenient as possible. For example, our walk-in compartment permits easy, quick access to the filter tubes from the top or clean air side of the filter. And simply by removing two bolts, the filter tube and frame can be lifted out.

The cleaning nozzle is positioned well above the filter tubes. The alignment of the nozzle manifold is not critical. There is no close clearance to create problems. Direct contact between the manifold nozzle and bag is not required because the on-rush of air creates a very short but highly effective seal while cleaning the tube.

Finally, the RF filter's air pump system virtually eliminated the problem of cold weather component freeze-up common to high pressure pulsed filters. And, the uncomplicated air pump can be mounted at ground level where it can be easily inspected.

Uses positive filter bag grounding.
The galvanized wire tube frames are attached to the tube sheet by two machine screws, this insures a positive ground connection is always maintained with bags and cages during operation. No straps or wire are required. With two grounding screws providing positive ground there is no problem with thick paint on tube sheet or loose straps.

Air-Cure keeps costs down
while the RF filter goes up.

We've done everything possible to keep your installation and expansion costs to a minimum. It's shipped as an all-welded unit, that can be lifted as one piece during installation at your site. It can also be supplied in bolt together sections if required for installation purposes.

Download RF Filter Brochure (730KB PDF)
Download Rotary Car Dumper Brochure (250KB PDF)

 

Air-Cure Inc. RF Filter