John Thompson’s Package Boilers business unit recently completed a contract for the conversion from high voltage electrode boiler plant to coal-fired boilers at SA Breweries’ Newlands brewery in Cape Town.
The process steam for the brewery has been provided for many years by a single large electrode boiler, but this has become uneconomical due to the steeply rising cost of electricity.
Before making the conversion the brewery was required to commission an environmental management plan to ascertain the impact of the proposed coal-fired boilers on the environment.
The brewery overlooks the Newlands cricket ground and is situated close to residences in the suburb and is required in terms of the environmental regulations to maintain emission of particulates at under 120 mg/Nm3. The conversion project included bag filters to limit emissions from the coal- fired plant.
SAB however set the limit more strictly at under 50 mg/Nm3 in line with its own environmental policy.
John Thompson was awarded the contract in April last year and completed it at the end of September this year. The electrode boiler has been replaced by two of John Thompson’s latest high efficiency 10,5 t/h Europac coal-fired package boilers. The ongoing output of these primary boilers is supplemented by a 3,2 t/h Enviropac biogas-fired boiler that the division supplied and installed under an earlier contract.
John Thompson provided the emission control equipment as part of the conversion contract, with each coal-fired boiler being served by its own reverse-pulse bag filter. The bag filters were designed and supplied by John Thompson based on in-house technology well-proven at local power stations.
During acceptance tests conducted by an independent company the maximum particulates emissions on both boilers were well below the required limit.
A 25 t/h twin furnace oil-fired boiler was retained for standby purposes. Other equipment supplied and installed by John Thompson under the contract included an accumulator, a coal- and ash- handling plant, a feedwater storage tank, a 31 m high chimney stack and interconnecting ducting.