Providing a complete filtration system for odour removal

DESOTEC designed the system to meet the client’s specifications and German safety and emissions standards. It took four to six weeks to build on site, and has the following main features.

1. It is a valve system based on a lead-lag configuration. The first filter adsorbs the VOCs until the carbon is saturated, with a second filter in place as polishing step. The valve system is used to divert emissions to the second filter while the first is exchanged by DESOTEC’s truck with the replacement filter. Once the new filter with fresh carbon is put in place, it takes on the role of polishing filter. When this second filter is saturated, emissions are rerouted back to the first filter while the second is exchanged.
   This is cost-effective, as it enables clients to use filters until they are fully saturated and avoid any downtime while filters are exchanged. The valves could also be used to bypass the filters altogether in the event of a problem.
2. There are two fans, placed in parallel, which can automatically adjust their speed depending on how many production lines are running to improve energy and cost efficiency. Only one fan is in operation at a time, with the second as a back-up in case of a fault in the first.
3. The fans are contained in noise boxes, with a limit of 75 dB at one metre’s distance. As the fans are near the factory entrance, the client wants to keep noise levels low.
4. The system includes an INERTI-BOX to detect hotspots. These hotspots could occur when a high concentration of VOCs is adsorbed by the carbon, causing the filter bed to glow. This is a safety feature developed by DESOTEC that incorporates a carbon monoxide (CO) sensor. If CO is detected, the valves to the related filter will automatically close, and the filter will be filled with nitrogen to displace the oxygen and prevent fire. After a cooling down period, the filter can be put in operation again.
5. It has a VOC monitoring system, so the client can see when a filter is becoming saturated and arrange for it to be exchanged. This enables the client to comply with emissions limits at all times, rather than wait for an external monitoring company to visit and then potentially have to exchange the filter as a matter of urgency.
6. As well as the mechanical and engineering scopes, DESOTEC designed and installed the full electrical scope according to the client’s specifications. This allows control of the system from either the dedicated electrical cabin, or from the plant’s main control room.

Despite all these features and associated work such as ducting, the final installation is very compact.