When Ford decided it was time to refurbish and upgrade two primer ovens and systems at its Dagenham plant in Essex, UK, the company looked to the future. Against a worldwide background of rising concern over environmental issues and pollution, Ford decided to make use of the opportunity to reduce VOC emissions.
They aimed for a system which would meet emission regulations for the foreseeable future, recognising that better environmental controls would enhance relations with the local authority and the community.
However, they also achieved an added bonus - the system designed and installed for Ford by Haden Drysys Environmental resulted in a significant improvement in oven efficiency.
The brief given to Haden by Ford was to strip out all the existing heating equipment on the two primer ovens and install new zone heaters. In addition, Haden was to introduce a VOC abatement system for each oven using recuperative oxidisers. The entire contract had to be completed in a three week shutdown period.
A NEW CONCEPT
Haden’s answer was a new oven temperature control system. Under the new system, the first zone of each oven is served by an indirect gas fired heater. However, all other zones are indirectly heated by the hot clean exhaust gases leaving the recuperative oxidiser, using three stainless shell and tube heat exchangers.
HIGH THERMAL EFFICIENCY
Hot waste gases from the stoving ovens pass into the recuperative oxidisers, where they are heated further to oxidise VOC to carbon dioxide and water vapour. Well over 99% of the VOC in the exhaust gases is eliminated at this stage.
Before being vented to atmosphere, the clean exhaust gas is passed through the six heat exchangers which transfer heat from the gases back into the ovens. The process has a very high thermal efficiency, which represents a very significant saving in fuel costs.
A TECHNOLOGY WITH A FUTURE
All Haden recuperative oxidisers are designed to achieve a high level of thermal Haden Drysys International Limited is registered in England No. 291950 a Haden MacLellan Holdings company efficiency, whether by primary heat recovery to the incoming contaminated air or by secondary recovery. For this reason alone, Ford’s decision to make use of this technology to improve oven efficiency is unlikely to be the last - especially as this is a flexible technology with varied applications.
The entire turnkey contract was completed on time during the shutdown period, so that no production was lost. As a result, Ford have not only made their ovens future-proof with regard to environmental legislation, but they have also made valuable efficiency gains. Two important goals have been achieved in one - impressive engineering by any standards.