Indirect Bath Heater Water expansion tank

Indirect bath heaters are mainly used in the oil and gas industry to heat process fluids. The mechanism takes place indirectly through a bath (utility bath) as opposed to heating directly by flame or furnace (direct fire-tube heaters).  The use of a bath promotes uniform heating and reduces the chance of hotspots. Due to the indirect nature of bath heaters the safety risks are much lower (combustible streams isolated) compared to direct fire-tube heaters, they can therefore be used in hazardous areas where safety is a concern.

The “indirect” name comes from the fact that a fire-tube is submerged in a bath that provides Tube-fire heater heating through the bath Uniform heating medium to a submerged coil containing the process stream. Usually the bath fluid is water but depending on the climate and heating requirements it can also be oil (capable Forced draft heat exchanger of heating process fluids to higher temperatures) or a mixture of water and glycol (used in colder climates Water expansion tank to lower the freezing point).

Hotspots often occur in direct fire-tube heaters Combustion stream as a result Heating efficiency Burner water bath of carbon build up on the fire side of the tubes. If left unchecked this build up can be a source Pressure drop in gas of process fluid degradation and may lead to ruptures, explosions and leaks.

Typically, FARAN’s Furnace gas heating indirect bath heater Gas station pressure drop s achieve around 50-55% heating efficiency. This relatively low efficiency compared to direct fire-tube heaters is a result of the number of heat transfer steps involved. Typically Water expansion tank indirect bath heaters are used where the flow rate of the process stream is low and operations Radiant and convective may be unattended, they could also be used to prevent coke formation on the tubes when low heat Furnace gas heating fluxes are required.

Variety of applications:

1.     Gas dew point heating: Heating efficiency high-pressure natural Water expansion tank gas heating upstream pressure regulation stations preventing condensation phenomena Radiant and convective due to Joule-Thompson effect.

2.     Heating of high-pressure natural gas upstream pressure regulation in order to prevent external icing formation.

3.     Fuel gas Forced draft heat exchanger super-heating upstream gas turbines.

4.     Gas heating Pressure drop in gas downstream low temperature storages.

5.     Hydrate prevention.

6.     Viscosity Radiant and convective reduction: Crude oil heating treatments to facilitate degassing and dewatering.

FARAN’s Indirect Bath Heaters main parts:

-       Main body

-       The coil or tube bundle Indirect glycol heater

-       The water Gas condensate expansion tank

-       The fuel Heating efficiency feed line

-       Burner (gas type, oil type or bi-fuel)

-       The fire-tube

-       Chimney

-       Burner management Heater shell system panel

-       Skid frame Indirect water heater and service platform

-       Insulation

The heater shell Uniform heating contains the fire-tube that allows a rapid heat transfer (both radiant and convective) Natural draft heat exchanger from the flame to the hot medium. The heat is transferred from the bath to the coil / tube bundle and the safely to the gas or the oil. The expansion tank allow the hot medium to be contained for the Indirect water heater thermal expansion due to the temperature increase. Level gauges and transmitters advise when additional Uniform heating water or hot medium is required and give alarms in case of overfilling.

Forced draft Vs Furnace gas heating natural draft:

Natural draft burner relies on a stack to create negative pressure at the burner inlet, Combustion stream which induces as much air as is required for combustion. These heaters are popular for remote Heater shell locations and/or locations with limited or even no power supply available.

Forced draft heaters are ideal whenever there is a low emission requirement, utilizing small bore fire-tubes in conjunction Heat exchanger with a combustion air fan. High velocities in small bore fire tube reduce the dead gas film region Tube-fire heater along the fire walls. This results in a reduced tube areas compared to their large bore counterparts, Tube-fire heater therefore, overall heater size is minimized creating a significantly smaller footprint while offering Gas condensate superior burner control compared to natural draft style heaters.

FARAN Process & Energy Furnace gas heating engineering company is able to design and manufacture different size of indirect water bath heater  which vary from 90 kW up to 10MW.