The Thermal and Pressure Engineering range of firetube hot water boilers employ a well tried and proven design concept based on the reverse flame combustion technology. This reverse flame combustion method provides an economical and highly efficient three pass gas flow system. The design incorporates a large pressurised combustion chamber allowing the first two passes of gas to be made in the combustion chamber itself. The scrubbing action of the reversing flame causes the gases to enter and re-enter the high temperature flame zone many times before making the third and final pass through the smoke tubes. Dimples in the smoke tubes further slow the passage of the combustion gases providing additional efficient heat transfer.
A major criteria in this design is the careful balance between radiant heating surfaces and secondary convection heating surfaces to ensure optimum efficiency when firing on either gas or oil.
Because of the use of a pressurised combustion system, the firetube hot water boiler operation is completely independent of exhaust stack draught. Exhaust stack sizes are therefore reduced with consequent installation savings.
This firetube hot water heater incorporates an extremely easy to clean design, as all heating surfaces can be reached easily simply by opening the burner door. This hot water boiler can be cleaned whilst still hot and still in service completely eliminating the need to shut down the system. An important feature of continued efficient operation, as each millimetre of soot or fouling reduces efficiency by 7%.
These firetube hot water heaters are of wet back construction with an insulated firing door for maximum heat retention and to reduce the possibility of condensation in the combustion chamber.