Explosion-proof industrial vacuum cleaner

We started the project by developing the technical concept to ensure compliance with the plant’s engineering infrastructure. Sleeves filter elements were selected to collect the sugar dust. In order to choose the right amount of filter elements, a series of calculations were carried out. The number of filters, size, and filtration surface area depend on the amount of dust produced at the mill’s floor.

The filter calculations provided data for the conceptual CAD design of the vacuum cleaner. The concept of the cylindrical shape unit comprised three main modules:

• a clean chamber, 
• dust collector, 
• a centrifugal separator. 

The developed concept underwent a series of (computational fluid dynamics) CFD simulations to determine the optimal air/dust flow through the filter’s internal cavity.

In the CFD analysis, the parameters of the centrifugal separator were determined and fixed (e.g. dimensions of the funnels, the dimensions of the inlet channel, etc.). Simulations were needed to ensure the required separation and deposition of coarse dust particles in the dust collector.

Further, we analyzed and specified the requirements for the high-pressure blower. Therefore, an additional set of CFD simulations was carried out, feeding the available data of the aerodynamic resistance inside the inner cavity with installed bag filters. The simulations suggested the use of a powerful blower delivering ~30 kPa pressure.

Pulse regeneration jet cleaning (filter regeneration/cleansing) system was selected based on our expert domain knowledge.

As we finished the technical concept development, the computer simulation results were incorporated in the preliminary CAD. Further work concerned engineering development and CAD detailing.

In the engineering development of the vacuum cleaner, special attention was paid to deliver the explosion-proof design. Therefore all the equipment modules (both external and internal) were developed in compliance with the ATEX requirements (explosion-proof electrical circuits, exclusion of friction-induced and static charge sparks). Part of the solution was to cast a conductive antistatic polymer coating to the unit’s metallic surfaces. Sleeve filters also ensured antistatic protection (conductive threads woven into the fiber, grounded to the body through a conductive mount). Additionally, all electric circuits and control electronics ( a custom PLC controller) were designed in conformity with the ATEX. 

Special attention was paid to the strength of the filter’s body. We had to be 100% sure the unit will survive the burst or explosion inside the hull. Therefore we ran additional FEA method analysis to ensure its integrity under explosion loads.

Additionally, we have designed a platform with a ladder at the vacuum cleaner’s upper zone to aid maintenance/repair convenience. Another developed feature was the top cover opening, aiding maintenance technicians in replacing filters without using heavy lifting equipment.

Having finished the design, EnCata mechanical and electrical engineers produced documentation and drawings for in-house unit production.

Use of CFD simulation methods for analyzing the filtering equipment’s internal cavity as early as at Concept Phase enables a much more accurate estimate of the filter system’s aerodynamics. CFD analysis helps the most efficient design and development of any air filtration equipment: it aids in selecting the centrifugal separator and selecting the most suitable blower/fan/turbine component of the unit.