John Thompson is a name synonymous with well-engineered industrial boilers, with roots going back to the industrial revolution of early 19th century England. Backed by a boiler manufacturing history
of over 140 years in numerous countries worldwide, the John Thompson factory near Cape Town has, for the last 60 years produced a wide range of Package Firetube Boilers for both local and international markets. Boiler designs have been developed continuously during this period to improve efficiencies and reduce emissions, in line with global environmental requirements.
The current steam boiler ranges, shown here, are all designed and manufactured in Cape Town, in compliance with the latest international design codes and are particularly suitable for local conditions. The boiler trade names are:
- coal/biomass-fired, outputs up to 22t.h (13.8MW)
- oil/gas-fired, outputs up to 40t.h (25.1MW)
- wood-fired, outputs up to 6t.h (3.8MW)
- oil/gas-fired, outputs up to 6t.h (3.8MW)
Steam pressures are available from 7 to 32 bar, dependent upon boiler size.
The Europac, Enviropac and Simpac designs are all direct-fired, three-pass, wetback type, while the Redipac is the reverse flame-fired type.
All boilers incorporate spiral-tube technology, which enhances convective heat transfer and reduces the boiler flue-gas outlet temperature to only 15 °C above steam saturation temperature at full load. This enables thermal efficiencies of up to 85% when coal-fired, 91% when gas-fired and 92% when oil-fired to be achieved - without an economiser. The firetubes are all spiralled in the John Thompson factory on their own specialised machine.
All boilers also incorporate corrugated furnaces, which are manufactured on a custom-built furnace-corrugating machine. These have superseded the plain furnace with bowling hoops and bar stiffeners. Apart from production advantages, the corrugated furnace also increases the radiant heating surface of the boiler. This results in lower tube-plate and tube-end metal temperatures at the inlet to the first tube-pass.
In addition to the four standard ranges of package firetube boilers, watertube boilers and waste-heat boilers are designed and manufactured to suit customer requirements; as well as ancillary plant including ash conveyors, multi-cyclone grit collectors, economisers, de-aerators, pressure vessels, pipe work systems, ducting and chimneys.