Process Bath Heaters

A process bath heater allows a user to indirectly heat process liquids and gases by submerging a process coil into a heated bath solution.

A process bath heater is a simple and safe method for indirectly heating various process mediums. A bath solution is heated by a fire tube style burner submerged at the bottom of the heater vessel. The bath solution then heats a submerged process coil, in which the flowing process medium is heated. Water-glycol mixtures are very common solutions for most low-temperature heating applications, and can typically be used up to 250F. Salt melts can be used to meet the higher operating temperature requirements in some specialized applications.

Water Bath Heaters

A process bath heater allows a user to indirectly heat process liquids and gasses by submersing a process coil into a heated bath solution.

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Fire Tube

Fire Tube

Immersion tube in a water-filled vessel, transporting hot gases or liquids from the burner during.

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Heater Vessel

Heater Vessel

Heat energy is transfer from fire tube to bath fluid. Water and water-glycol solutions are used for bath operating temperatures to ~350F. Heat transfer salts can be used for bath operating temperatures to ~800F.

Heater Vessel

Heater Vessel

Natural convection creates fluid circulation within vessel due to the density variation between the hot and cold bath fluid

Heater Vessel

Heater Vessel

Bath fluid transfers heat energy to the process heating coil. The coil then heats the process fluid inside it.

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Coil

Coil

Absorbs energy from the hot water to heat the process fluid.

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Bypass Valve

Bypass Valve

Controls process temperatures to keep bath temperatures consistent.

Features & Benefits:

No potential for direct contact between the products of combustion and the user process

Safe operation for combustible or hazardous processes

Flexible operating temperature and pressure range

Atmospheric operation for low temperature applications

No fluid or energy loss to make-up water, steam traps, or blow down

Saving in maintenance and energy costs relative to typical open loop steam systems

Many burner and fuel source options

Force draft fire-tube burners can be utilized for high efficiency and low NOx requirements

Design Features

 

Fuel Source and Burner Flexibility Standard or engineered burner configurations are available for use with both traditional and alternative fuel sources. Low emissions burners can be supplied to meet all emission requirements (e.g., Low NOx, Best Available Control Technology).
Advanced Control Systems Complete control systems are engineered to optimize system safety and performance. Sigma thermal can supply simple and cost effective standard panels, as well as full process automation and PLC based combustion control / BMS.
Coil Configuration Flexibility Coil flow path and metallurgy are engineered for each customer’s process requirements. Sigma Thermal has extensive experience in process coil design for multi-phase fluids, viscous hydrocarbons, suspended solids, and various gaseous mixtures.

mact emissions compliance

Water Bath Heater

The bath solution is heated by a fire tube style burner submerged at the bottom of the heater vessel. Water-glycol mixtures are very common solutions for most low-temperature heating applications, and can typically be used up to 250F.

Salt Bath Heater

The principals of operation of a salt bath heater are similar to that of a water bath heater. A fire tube burner is submerged at the bottom of the heater vessel with a process coil submerged at the top. In lieu of water or water-glycol a molten salt is used. Molten salts can be used at much higher operating temperatures; as high as 1,000F. The higher operating temperature capability does come with challenges. The freezing point of these salts can be close to 300F.

Direct Fired Reboiler

weir bath heaterSometimes referred to as a weir bath heater, this is a slight variation of a traditional water bath heater that does not utilize a process coil. This type of heater is most commonly used as a direct fired reboiler for amine and glycol solutions. The bath vessel contains a fire-tube and a weir at the end of the fire-tube. The process fluid is circulated through the bath vessel in direct contact with the fire-tube. After the process fluid is heated, it falls over the weir where the return line sends it back to the process user.