Project RC – Ducting System Design and Installation with Drop Out Box to allow reuse of Existing Filter

The client in Ellesmere Port is involved in creating novel recycled glass products, emphasising the energy savings of using recycled product over creating new.

As part of a new trial, the company had used an existing filter but suffered a fire due to carryover of debris in the recycled material. As part of further investments into an extended trial plant, the client wanted to ensure that they did not have a repeat fire and were encouraged to take preventative measures by the fire brigade and their insurers.

The solution was to replace the ducting in the revised plant layout, incorporating a drop out box before a fire detect and suppression system. In tandem, the drop out box would remove the majority of larger airborne matter such as parts of bottle labels and the spark detect and arrest system would ensure any sparks passing are caught and extinguished.

The ducting was designed to connect to the existing conveyor hood, then on to the drop out box inlet and over to the filter, designed within the constraints of the existing plant, to accommodate the spark detectors and quench system requirements.

Manufactured from 4mm mild steel, continuously welded and flanged and bolted, the ducting is of rigid construction for longevity.

Detection ports and water nozzle ports are designed into the ducting in specific locations.

The drop out box consists of a series of impingement plates, a low velocity section to encourage particulate drop out and a series of removable mesh plates. The collected matter drops to a removable bin, which is designed to be forklifted to any location or simply wheeled away.

Erection involved three men for two days, using a telehandler and cherry picker to lift ducting sections which had been built up on the ground. The cherry picker allowed easy access for fitting.

The drop out box and interconnecting ducting are installed similarly. A hot works permit was obtained before welding the ducting transformer to the existing filter. Furthermore, the transition piece was designed oversize to slow down the gases entering the filter but also to allow welding of the transformer to a smaller cut out, minimising the risk of sparks entering the filter.

The Spark detection and arrest system was fitted following the main mechanical works and commissioned shortly after. This system should now off robust protection the bag filter and allow the plant to run without interruption.

Additionally, Filter Designs measured up the plant to allow the detailed ducting design. This was fabricated locally and installed using local labour.