Water Bath Heater

Explore the equipment

Heat high-pressure gas upstream of a pressure letdown station so that Joule-Thomson cooling across the choke does not drive the gas below its hydrate formation temperature. An indirect bath transfers heat from a fire tube to a process coil through a water bath, so flame never contacts the process stream.

Components

• BurnerBNR-101

  Fires into the submerged fire tube.

• Fire tubeFT-101

  Carries combustion gases through the bath, transferring heat to the water.

• Water bathBATH-101

  Intermediate heat transfer medium between fire tube and process coil.

• Process coilCOIL-101

  Carries high-pressure process gas through the bath to pick up heat.

• Low level switchLSL-101

  Detects loss of bath level and trips the burner.

• Relief valvePSV-101

  Protects the bath shell from overpressure.

• Exhaust stackSTK-101

  Vents products of combustion to atmosphere.

Operating states

• Startup

  Bath level confirmed, purge complete, pilot proven, burner brought to low fire while bath temperature climbs to setpoint.

• Normal operation

  Burner modulates on bath temperature. Heat passes from fire tube to bath to process coil. Gas leaves the coil warm enough that letdown does not form hydrates.

• Shutdown

  Burner secured, post-purge completed, bath allowed to cool. Process flow may continue until the coil outlet approaches hydrate conditions.

Failure scenarios and safeguards

• LESSLevel

  Low level switch trips the burner before the exposed fire tube reaches damaging temperature.

• NOFlow

  High bath temperature cuts the burner, and the relief valve protects the coil against thermal expansion of trapped gas.

• MORETemperature

  High temperature trip cuts fuel; relief protects the shell and the low level trip provides a second line of defence.

• NOCombustion

  Flame supervision closes the fuel valve on loss of flame and forces a full purge before any re-light attempt.

• OTHER THANContainment

  Gas detection alarms and the operator shuts in the unit; relief protects the bath from the pressure of the released gas.