Dust Collector Theory and Design
Adapting to Application Requirements
Dust control and dust collector / filter design requires multiple design considerations to be taken into account, for instance: Air volume, filter area, ambient conditions, cleaning cycle, flow management, fluid mechanics and element geometry are all crucial. Product characteristics such as particle size and shape, toxicity, bulk density, bonding, agglomeration and moisture content also play an important part in the design process.
Therefore, not only is it necessary to choose the correct media for the product being handled, it is also important to select the correct cartridge or bag/sock format and appropriate cleaning system for the application.
Our design expertise covers the latest techniques in LEV systems and capture hood design. We have full 2D and 3D CAD design facilities. We provide specific application expertise, by focusing upon customer requirements, using either ‘off-the-shelf’ or bespoke solution, providing the most appropriate and cost effective results.
If required we can carry out stack dispersal and stack height calculations, for compliance with local authority or environmental regulations, Part A or B processes. EPA (1990). D1 guidance (Dispersion) notes are used for stack height calculations, using estimated emission results and guideline concentrations. MCERTS Stack emission monitoring can be carried out to confirm results and performance guarantees. Click: Stack and Continuous Monitoring Systems
Our unique understanding and in-depth knowledge of both Industrial Ventilation Systems together with Hazardous Area Classification and DSEAR Risk Assessments enables us to offer solutions to control potentially explosive atmospheres for fumes, vapours, gases and dusts and reduce extents of zones and in so doing possibly saving many thousands of pounds. This also enables a single source supply for area classification / zoning, and design of General and Local Exhaust Ventilation, Monitoring and Control Systems for handling of potentially explosive / flammable atmospheres.
We can design/supply/install airflow control and monitoring / alarming systems for use in potentially explosive atmospheres. This includes supply of ATEX pressure, flow sensors and systems requiring duty/standby, battery backup or supervisory control systems.
Some advantages of cartridge filters over bag / sock dust collector filters.
Cartridge Technology offers extremely compact solutions (up to 50% saving in footprint area) and efficiency guarantees, which are not achievable with the use of conventional bag type medias
Due to the reduced core volume of a cartridge filter compared with an equivalent bag element, the effect of a given quantity of cleaning air is much greater, leading to improved cleaning efficiency. The development of the compressed air cleaning wing systems (for cartridge filters), provides cleaning at lower pressure with lower noise, compared to reverse pulse-jet filters, providing enhanced cleaning and saving on compressed air usage. See below.
Higher filtration efficiencies can be obtained with cartridge filter media compared to filter bag needle felts and membranes: PTFE membranes can be applied to the base polyester, of cartridge filters offering much greater efficiencies (100% down to 0.5 µm) with excellent product release characteristics. Nano and micro-fibre membranes can also be applied more readily to the base polyester, of cartridge filters media.
Maintenance on conventional bag house type filters can be a lengthy, dirty and intricate procedure. There are also health and safety issues to be considered – particularly if the products being handled are of a toxic nature. Cartridge technology has enabled much simpler and easier filter replacement, offering much faster, cleaner and simpler solutions – not least is the consideration that for a given filter area, the number of filter cartridges is far less than the equivalent bag type solution. For hazardous / toxic dusts safe change filter solutions are generally easier to implement with cartridge filter technology and fixings.
Spun-bonded polyester with / without surface treatments, can be cleaned with steam pressure washers; however surface treatments may be compromised / damaged.
Some advantages of bag/ sock filters with respect to cartridge filters
Bag filters are generally lower cost than cartridge filters (although more filters are required for same air-flow). For processes requiring regular filter changes (due to product changes), this may be advantageous.
Readily agglomerating and/or oily dusts can ‘stick’ within cartridge filter pleats, preventing efficient filter cleaning.
Bag filters (Needle felts) can be easily washed, however surface membranes can be damaged in the washing process.