CASE STUDY - VOC EMISSIONS FROM A FLEXOGRAPHIC PRINTING PRESS
A flexographic printing press from the Middle East contacted u...
CASE STUDY - VOC EMISSIONS FROM A FLEXOGRAPHIC PRINTING PRESS
A flexographic printing press from the Middle East contacted us for a Regenerative Thermal Oxidiser to be installed in its premises for the disposal of VOCs (Volatile Organic Compounds) carried by the hot air which is used to dry the printing ink. This is a statutory requirement in this country where the VOC content of the outgoing air should not exceed 50 mg/Nm3.
The RTO derives its name from its design. VOCs have a high calorific value and burn well when ignited. 2 bed systems are usually the most common due to their relative simplicity. As heat is recovered through the ceramic beds, fuel requirement or the running cost of the RTO is practically nil, except for electric power needed for the fans.
The design of the RTO should be such as to allow every 2 minutes or so transfer of the gas entry from one ceramic bed to the other. This is primarily to facilitate raising the temperature of the unused bed which would have cooled somewhat during the 2 minute interval. Sometimes consideration of butterfly/poppet valve seal temperature resistance may post some limitations to the 2 minute transfer. In such a case, the PLC programme can be made to shift the beds once the outlet temperature reaches a certain maximum.
The client was pleasantly surprised to find that the RTO technology provided by us was as good if not better than what was usually offered by other similar manufacturers. Additionally, the competitive
The RTO Regenerative Thermal Oxidizer was provided with an automatic and manual damper for the inlet of gas and an emergency stack, in case of excessive pressure build up in the ceramic beds for any reason. There are butterfly/poppet valves as required to control the flow of the gases, a bag filter, in case the waste gas carries any dust particles and a PLC panel for automatic operation of the entire system and a stack of 12 m height. The whole system is operated using a HMI screen.
Due to the large size of the equipment, it would not fit into any standard container for shipment. A couple of flat rack containers used and the system was loaded on this and other standard containers.
The installation and commissioning of the plant was in a location which was completely new to our team. However, since most of the work was done in Haat?s shop, it was only a simple matter of putting the system together at the site and it was up and running quickly.
The regenerative thermal oxidiser was tested and commissioned and performed well and achieved the desired results with the client being happy with the low capital and running costs and the performance.
“Haat can be relied on to meet urgent requirements.” – Sanjay Tulshyan, Managing Director, Technical Associates, Nepal.
