Dust Suppression Hopper DSH

The Dust Suppression Hopper (DSH) prevents the formation of dust clouds during the transfer of bulk solids.

DSH operating in the exact same environment as the telescopic bellows, demonstrating its performance.

Originally developed to tackle dust emissions at a fertilizer plant, the DSH is now used for a range
of materials including:
• Foodstuffs – salt, sugar
• Minerals and quarry products – bauxite, gravel, kaolin, sands, soda ash
• Grains and stock foods – corn, barley, sorghum, soya beans, wheat
• Fertilisers– superphosphates, lime, potash

This list is far from exhaustive and recent additions include compressed wood pellets and other pelleted products for the biomass industry. In general suitable materials are dry, granular and free flowing, as fine, sticky powders do not perform so well.

The design of the DSH marks a radical departure from conventional telescopic bellows and produces a denser, less aerated flowing material phase.

A conical outer hopper is suspended from the top frame of the unit by a Patented Suspension system. Within the hopper is Patented Device designed to control the flow through the hopper. As material flows into the DSH its weight causes action on the suspension system and the outer hopper lowers relative to the Flow Control Device. The continuous oscillation up and down during discharge maintains the characteristic solid-looking stream of product.

Unlike a telescopic bellows a DSH is installed directly beneath a feed point, suspended at some height above a target, such as a lorry filling bay. Aside from the constrained up and down movement of the hopper this height is maintained throughout discharge. Most of the complexities associated with the telescopic bellows design are therefore eliminated. The DSH has no internal moving parts and requires no utilities for operation.
The way in which the DSH operates leads to material discharge in the form of a densified, almost solid stream containing very little air. As material flows into the hopper, from the feed silo, natural agitation and settling lead to limited air release. Then, because the material is pushed out of the annulus against the opposing pressure of the suspension system it undergoes a further ‘squeezing’ action. The result is a ‘condensed’ stream of material that is extremely tolerant of fall height. During transfer any dust present is entrained, and drawn down into the material column, and there is minimal dust emission when the product hits the ground. The squeezing out of air also largely
eliminates segregation.
The simplicity of the DSH translates into low maintenance costs and the almost complete
prevention of dust release for a many industrially significant bulk materials. However, the DSH, like many newer technologies, can carry a higher upfront capital cost. This raises the question of how to financially assess different options for bulk materials loading and how to put a value against the potential benefits afforded by alternative systems.

The Dust Suppression Hopper (DSH) prevents the formation of dust during loading operations tackling this potential problem at its source. Experience suggests that this technology not only solves critical HSE issues but also pays its way with economic benefits accruing in the form of reduction in clean-up, maintenance and product loss.