What are they and what is their purpose?
Indirect water bath heaters are used for the heating of a process fluid.
They are used to increase the fluid temperature according to the process requirement.
Typical and most common applications are either in the RMS (reducing and metering station) or in the fuel gas treatment plant for fuel gas supply to power plant.
Water bath heaters are indirect type because the heat generated by the combustion of a fuel is transferred to the process gas through a medium. This medium can be either water or a mix of water and glycol or diathermic oil.
Indirect water bath heater consists of the following parts:
– atmospheric shell which contains water, complete of expansion tank
– coil, installed inside the shell, where process fluid passes through
– flame pipe, installed inside the shell, where combustion takes place
– stack for exhaust smoke emission
– burner for the combustion of fuel gas.
Mechanical design and construction
Indirect water bath heater is designed according to API 12 K.
Coil, that is the pressure part of heaters, shall be designed according to the most common international codes such as ASME VIII div.1, ASME B31.3 or EN rules.
Indirect water bath heaters are normally made of carbon steel, with the required corrosion allowance.
Indirect water bath heater sizing is carried out according to API 12K rules; efficiency can be selected from a minimum of 75% up to 90% by means of sizing program, to guarantee thermal efficiency and process performance.
Accessory and instrumentation
Indirect water bath heaters are supplied complete with all necessary valves, instruments, control panels and all accessories necessary for safe operation.
In 45 years of life Forain has produced a lot of indirect water bath heaters which have been installed in almost all the countries of the world in onshore plants.