A breath of fresh air from Dustech
Industrial air pollution control equipment specialists Dustech Engineering have installed a new dust collector and bag cleaning system at Gypsum Industries’ plasterboard factory in Kingscourt, Co. Cavan.
The client’s existing electrostatic precipitator had been running since 1979, handling elevated-temperature exhaust gases from mills and kettles used in the production of gypsum for the manufacture of wallboard and plaster.
Dustech were commissioned to custom design and develop a dust-filtration solution at the factory to minimize the aging air cleaner’s irregular shutdowns, which were affecting production. This was achieved by designing and installing a top bag loading pulse jet fabric filter – Model TE 0512 – with a total needlefelted fabric area of 2,430m2. This is essentially a ‘very large cabinet’ mounted over twin lower trough hoppers.
The upper casing of the filter includes a lower inlet dirty gas area with central enlarged drop out and baffles to distribute incoming dirty air evenly into the filter elements, which are suspended on the dividing cell plate. Elsewhere, there is an upper clean-air compartment, accessed by hinged lift-up doors, which shield the jet pipes and Prosnap fix filter bags.
As the particulate matter builds up on the outside of the filters, it is periodically removed by momentary pulses of high-pressure compressed air directed through the venturis on each individual bag top.
These shape the initial pulse and induce secondary air into a large ‘bubble’ of air that travels down inside the bag, opposing normal flow but expanding the bag, thereby casting off the collected dust mat and causing the agglomerated fines to fall into the lower hopper.
Reliable control of the bag cleaning system is essential for optimum operation and conservation. The system incorporates: twin 54-way sequence timer units with microprocessor management; manifold pressure transducers; and in-duct broken bag detectors. These vital components ensure an alarm is raised when the solenoid-activated diaphragm pulse valves fail and when bags need to be replaced.
Dustech have designed a complete system that is easy to access and maintain. The roof of the filter, for example, is fitted with a weather-protective housing, fully enclosing the pulse valves and bag change outs. There is also full insulation of all surfaces, including trace heating to the hoppers, to help prevent condensation and moisture problems.
