What is a direct contact heat exchanger give some examples?

In a direct contact heat exchanger, the exchange of heat takes. place by direct mixing of hot and cold fluids. And the transfer of heat takes. place simultaneously. Example: cooling towers, jet condensers, direct contact feed.

What is direct and indirect heat exchanger?

Recuperative heat exchangers Indirect contact heat exchangers keep the fluids exchanging heat separate by the use of tubes or plates etc.. Direct contact exchangers do not separate the fluids exchanging heat and in fact rely on the fluids being in close contact.

Which of the following is a direct type heat exchanger?

Explanation: Spray and Tray type is a Direct Contact Type heat exchanger which involves the transfer of heat between two immiscible fluids by bringing them into contact at different temperatures.

What are the 4 types of heat exchanger?

4 Types of Heat Exchangers and Applications

  • Double Tube Heat Exchangers: Double tube heat exchangers use what is known as a tube within a tube structure.
  • Shell and Tube Heat Exchangers:
  • Tube in Tube Heat Exchangers:
  • Plate Heat Exchangers:

What is direct type heat exchanger?

Direct-contact heat exchangers (DCHEs) make use of gas-liquid phase change heat exchanger within the working fluid. That is to say, DCHEs put to use heat transfer between two kinds of fluid in the absence of a partition.

What is heat transfer by direct contact called?

Conduction is the transfer of energy from one molecule to another by direct contact. This transfer occurs when molecules hit against each other, similar to a game of pool where one moving ball strikes another, causing the second to move.

What is direct heating?

Direct heating can fundamentally be defined as the control of thermal energy absorbed or rejected through manipulation of exogenous factors. In other words, it involves placing an SMP into a hot environment.

What is direct heating process?

In direct heating systems, heat is generated directly within a material by passing electric current through it, or by causing controlled exothermic reactions, or by exciting atoms or molecules inside the material by electromagnetic radiation (e.g., microwaves).

What is difference between lmtd and Amtd?

We can use AMTD approach when the temperature drop at inlet and outlet are same ie, in case of balanced heat exchanger (heat capacity rates are equal), like gas turbine applications. When is LMTD invalid? LMTD is required when Temperature difference of hot and cold fluid across length of tube varies.

What is meant by fin efficiency?

Fin efficiency is defined as the ratio of actual heat flow of the fin to that which would be obtained with a fin of constant temperature uniformly equal to the base surface temperature, that is, one with infinite thermal conductivity.