Reverse Pulse Dust Collectors: Operating Principle, Components, Conditions, Problems and Solutions

In global practice, reverse pulse cleaning is considered a rather outdated regeneration method, as it is suitable only for easily cleanable dusts and does not allow high filtration velocities. The permissible filtration rate should not exceed 0.5–0.9 m/min.

This regeneration method is applicable for cartridge or bag-type dust collectors.

Cleaning of filter elements is required in any dust collector, as particulate matter accumulates on their surface during operation and needs to be regenerated.

In a reverse pulse dust collector, used when solid deposits accumulate on the inner surface of a bag or cartridge, the airflow is reversed by supplying fresh or cleaned air for regeneration. To perform reverse pulsing, the filter is either sectionally or fully isolated. The airflow used for regeneration is typically up to 10% of the cleaned gas volume.

Within the collector body, each bag or cartridge is equipped with a dedicated tube through which compressed air is delivered in pulses at predetermined intervals. The reverse airflow dislodges the layer of dust formed on the inner surface of the bag or cartridge, causing it to fall into the hopper, from where it is removed using a screw conveyor or other extraction device.

The spent purge air is discharged back into the unfiltered gas duct through the supply pipe.

To enhance regeneration efficiency, the reverse pulse jet dust collector is often equipped with a mechanical shaking system. A specially designed shaker mechanism moves the top cover, to which the filter element is attached, up and down, assisting in dislodging the dust.

• Housing: Made of steel or stainless steel, hermetically sealed. Must withstand the operating pressure and temperature. Designed with consideration of airflow to minimize turbulence.
• Filters: The primary component for contaminant capture. Can be bags or cartridges.
• Valves: Control the delivery of the reverse pulse. Their frequency is set according to solid particle loading.
• Hopper: Container where dislodged dust falls after cleaning. It may be equipped with rotary or slide valves for continuous particulate removal.
• Fan: Creates airflow through the system, ensuring movement of contaminated and cleaned air. Duct design minimizes pressure losses and turbulence.

During the design process, it is necessary to optimize the filtration area: the larger the area, the lower the load on each element and the smaller the differential pressure. The design should allow easy replacement of filters and cleaning of the dust collector. Sealing prevents pollutant leakage and ensures safe operation. Condensate drains may be installed if the gas is humid. The use of anti-adhesive coatings for sticky or aggressive particles improves filtration performance. A modular construction facilitates easy system scalability.

A modular dust collector reverse pulse design enables scalable configurations, with easily replaceable filters, optimized ducting, and efficient pulse valve control.

Due to the complexity of the design, pulse-jet cleaning is used only for the regeneration of thick filter materials such as felt, wool, or sometimes high-strength synthetic fabrics. For bag manufacturing, fiberglass or needle-punched felt is commonly used. The choice of material is determined by the composition of the particulate-laden gas, which may sometimes be chemically aggressive. Thin or weak materials may rupture or wear prematurely due to the dynamic air pulse.

The gas temperature is limited by the thermal resistance of the filter media. For standard felt, the permissible operating temperature is typically 120–150 °C.

Use of the system is limited to gas streams that do not contain aggressive chemical components, abrasive particles, or sticky solids, which could clog the air-purifying element or accelerate its wear.

In a dust collector reverse pulse system, the pressure must be selected according to the thickness and strength of the filter element. Excessive pressure can cause mechanical damage to the filter, while insufficient pressure does not provide effective cleaning. The optimal pulsing frequency is determined based on differential pressure measurements and dust concentration.

The system is designed for cyclical cleaning, with pulse intervals adapted to particulate load and the properties of the filtration media. Continuous operation without cleaning is not permissible, as it leads to increased differential pressure and reduced throughput.

Advantages of this technology include simplicity, high filtration performance, and the ability to operate in an almost continuous mode.