Cement Dust: Methods of Air Cleaning, Filters and Systems, Silo Aspiration and Safety Measures

The following systems can be used to cleaning cement dust:

• bag filters;
• cartridge dust collectors;
• cyclones.

A typical bag filter functions as a proficient dust absorber cement operations rely on, with its construction comprising a carbon steel housing, a collection hopper, structural supports, filter bags, a valve assembly, and an automated cleaning mechanism.

In operation, polluted flow is drawn into the unit through an inlet duct and directed through the filter bags. These bags are commonly made from materials such as PTFE, fiberglass, or polyester, chosen for their high efficiency in trapping fine and dangerous particulates. The cleaned flow is discharged through an outlet, while the collected solids build up on the bags' outer surface. To ensure consistent performance and avoid a significant increase in pressure drop, this accumulated pollutant layer is regularly cleaned off the bags by an automated cycle.

A cartridge dust collector traps particulate matter on the outer surface of its pleated media, which is mounted in quick-release cassettes or modules. This configuration is vital for protection from cement dust in enclosed spaces, since the clean flow that passes through the microporous filter can be safely returned to the workshop atmosphere. The fundamental operating principle and design share significant similarities with a bag filter. These collectors provide superior collection efficiency for micron and sub-micron-sized particles, successfully capturing the particle dust cement dome enclosures and similar facilities produce.

The assembly of the unit includes a support frame or platform for installation, a primary housing with separate inlet and outlet ducts, a port for connecting the compressed stream line, and an internal chamber that contains the plate for mounting the cartridges.

Available cartridge shapes include cylindrical, flat, conical, or oval, which are listed here from most to least preferred and effective. To handle a range of particle sizes, the inlet area can be equipped with a deflector. This component guides heavier, coarse particles down into the hopper, stopping them from contacting and prematurely clogging the cartridges.

An automated pulse-jet cleaning system is integral to the unit. Comprising an atmosphere receiver, diaphragm valves, tubing, and nozzles, it delivers short (0.1-0.2 sec), high-pressure (up to 8 bar) blasts of compressed stream to dislodge airborne particles from the cartridges. Situated directly below the filter chamber, the collection hopper can be outfitted with optional features such as an automatic or manual discharge valve, a fully automated evacuation structure, and a vibratory shaker to prevent the compaction and cementation of fine solids. Overall operation is managed by a comprehensive control and automation system, which integrates sensors for monitoring differential pressure, impurities level, and other critical parameters.

Cyclones are integrated with bag filters or cartridge collectors, serving as a primary pre-cleaning stage for the dust cement industry. In this configuration, the cyclone module removes the bulk of the coarse solids before the air proceeds to the secondary, fine-filtration stage.

Cyclones operate on an inertial-vortex principle. Polluted air enters the unit through a tangential inlet at the top. As the flow passes through the volute, it is set into a rapid, swirling motion. This vortex intensifies within the cylindrical-conical body, forcing solid particles outward by centrifugal force toward the inner walls. The particles lose kinetic energy upon contact, settle into the boundary layer, and descend by gravity into the collection hopper. The cleaned stream then reverses direction in a central upward spiral and exits through the top outlet, directed to a secondary filter for final polishing.

The following table will assist in selecting the optimal design for your dust dedusting for cement requirements.

Table - Comparison of Characteristics

Essential cleaning and safety protocols mandate the use of Personal Protective Equipment (PPE), local exhaust ventilation, and pollutants extraction systems. These form the foundation for comprehensive dust control cement plant operations.

A systematic cleaning procedure is critical for effective dust control in cement plants. The process should begin with a thorough dry-cleaning stage using industrial vacuums and brushes to remove the bulk of the particulate matter, followed by a controlled wet wiping or mopping of surfaces to capture residual fine particles.

Effective cement control dust flow measures at storage facilities require improved paving systems, regular cleaning of roads and grounds, and a vehicle speed limit of 15 km/h. In dust-generating areas, handling equipment must be fully enclosed, with exhaust ventilation extracting stream from beneath the covers.