Heat Exchangers

Heat exchangers are devices that take heat energy from one stream and pass it on to another stream which is in deficit of this heat energy. It tends to equalize the temperatures if both the streams are at same mass flow rate and both sides of the heat exchanger have same fin area in the direction of flow.

Capri manufactures heat exchangers which exchange heat between two fluid streams. Such types of heat exchangers are called direct contact heat exchangers.

Direct contact heat exchangers involve heat transfer between hot and cold streams of two phases in the absence of a separating wall. Such heat exchangers can be classified as:

  • Gas – liquid
  • Immiscible liquid – liquid
  • Solid-liquid or solid – gas

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Most direct contact heat exchangers fall under the Gas- Liquid category, where heat is transferred between a gas and liquid in the form of drops, films or sprays.

Such types of heat exchangers are used predominantly in air conditioning, humidification, water cooling and condensing plants.

PHASES

CONTINUOUS PHASE

DRIVING FORCE

CHANGE OF PHASE

EXAMPLES

Gas – Liquid

Gas

Gravity

No

Spray columns, packed columns

   

Yes

Cooling towers, falling droplet evaporators

Forced

No

Spray coolers/quenchers

Liquid flow

Yes

Spray condensers/evaporation, jet condensers

Liquid

Gravity

No

Bubble columns, perforated tray columns

Yes

Bubble column condensers

Forced

No

Gas spargers

Gas flow

Yes

Direct contact evaporators, submerged combustion