Sieving and screening powdered products greatly contributes to dust generation, not only when product is poured or dumped on to the sieve screen, but when the sieve applies high powered vibration to the mesh screen.
Farleygreene are all too aware that dust control has become an ever-increasing concern for manufacturers in a variety of industries where product processed in bulk can produce a large amount of dust. Regulatory standards are also becoming increasingly tight as inhalation of airborne dust particles are contributing to poor health of operators. Heavier dust particles that settle on equipment also add to the risk of fire and explosion, as well as contributing to unnecessary maintenance and a shorter lifetime for costly equipment.
DUST CONTAINMENT
Farleygreene have developed a range of different solutions that help control dust when sieving and screening. Their Sievmaster range offers a variety of different sieves designed to handle various requirements within manufacturing. The most popular product for plant operators is their Slimline sieve, available in four different diameters depending on the throughput requirement. The two smallest Slimline sieves are also sold with a sack tip option, as the ‘Sievmaster Easilift’, designed for processing powders in bulk from sacks or containers. Providing a sack rest table and hooded enclosure, sacks up to 50kg can easily be cut and emptied into the sieving compartment. When in use, the sack tip hood remains vibrationally isolated from the sieve, minimising impact on the operator and generation of airborne dust from dispensing the product. A dust-tight seal to the sieve is maintained thanks to the metal detectable silicone diaphragm seal. The hood is available with a pneumatically assisted door that can be closed when the sieve is in use to suppress dust as powdered product falls into the vibrating sieve below. This helps keep the dust contained and prevents it from entering the surrounding atmosphere, protecting the operator, preventing loss of product and mitigating the risk of contaminates entering the sack tip station when not in use.
DUST EXTRACTION
The standard dust hood is fitted with a Ø150mm dust extraction port, ready for connection to an external extraction system to draw air-borne product into the hood and away from the operator during sack tipping. Alternatively, local dust extraction units can be built directly into the dust hood itself. These are available in two varieties; either with an electric fan or a pneumatically powered vacuum pump. Both draw air through a set of filters and feature reverse jet purge cleaning. This means that when the dust hood door is closed, a powerful pulse of air is sent back through the filters, blowing any trapped product off them to fall down to the sieve, minimising loss of product.
EXPLOSIVE RISKS
In order to prevent any explosive risks from powder generated during processing, Farleygreene Sieving equipment conforms to the latest ATEX requirements and can be certified for Zones 20, 21 and 22, depending on options.
Several Earthing options are also available including, 430 Chrome steel earth clips and food-grade conductive mesh ring gaskets. However, one of the more popular options is the direct mesh earthing bar which screws directly into the mesh ring through a slot in the body of the sieve. This offers a way of ensuring the mesh is properly earthed without having to open the sieve.
HYGIENE CONCERNS
Particularly for the food industry, the generation of excessive dust can also contribute to hygiene concerns as equipment can be more difficult to keep clean. Therefore, a significant advantage of a combined sieve and sack tip station is that transfer between separate machines is eliminated, reducing the risk of contamination or product leakage.
Earlier this year, Farleygreene released a new product to their sack tip range, the Easilift Ultra, designed specifically for the hygiene conscious food industries. The hood on the Ultra version is rounded with fewer crevices, improving product flow and cleanability. The externally mounted sack tipping table mitigates the risk of contamination of the product from the outer surface of the sacks or containers, and folds away when not in use to minimise surface areas prone to dust collection. The door has also been designed without welding to reduce deformation and provide a flatter sealing surface, ideal for dust suppression. It is also worth noting that this more hygienic style hood is also available with the pneumatically assisted door and integrated dust extraction system.
Nearly all materials handled in bulk generate dust, but these containment and control solutions offered by Farleygreene can help manufacturers take preventative action to keep operators safe.
Farleygreene have been designing and manufacturing sieving equipment at their UK factory since 1976, supplying machinery to some of the world’s largest manufacturing companies. To learn more contact us here or call +44 (0) 1256 474 547.