What is mean metal temperature in heat exchanger?

The metal temperature is calculated much the same way in all cases. In heat exchangers the tube metal temperature will be between the hot- and cold-side fluid temperatures. On the other hand, if one stream is cold water, with a minimum film temperature, the metal temperature will be nearer the water temperature.

What is temperature approach in heat exchanger?

WHAT IS THE APPROACH TEMPERATURE? It is the smallest difference between the temperatures of the cold and hot streams. For example, if you heat a cold fluid from 80°C up to 100°C using a hot fluid at 105°C, the approach temperature of the heat exchanger is 105-100 = 5°C. The lower approach, the higher heating area.

What are the factors are involved in designing a heat exchangers?

Designing heat exchanger The main factors affecting the performance heat exchanger tubes include: fluid velocity, tube diameter, converter tube shape (U or cross shape), converter layout order (horizontal or vertical), and Venting valve, material of tube sheet and channel and location order of input channel.

Which points need to be considered in the design selection of a heat exchanger?

Heat Exchanger Types and Selection

• Application (i.e. sensible vapor or liquid, condensing or boiling)
• Operating pressures & temperatures (including startup, shutdown, normal & process upset conditions)
• Fouling characteristics of the fluids (i.e. tendency to foul due to temperature, suspended solids …)

What is MDMT in piping?

Let’s start by understanding what MDMT is; MDMT, Minimum Design Metal Temperature, is the lowest temperature that the vessel can withstand with the chosen material and thickness. It is a critical factor in designing a pressure vessel that depends on the environment where the pressure vessel has to be installed.

What is meant by approach temperature?

The approach temperature used in a shell and tube heat exchanger is simply the difference between the outlet and inlet temperature of the cooling water stream minus the difference between the inlet and the outlet temperature of the process stream.

How do you find the approach temperature?

Q. What is “Approach Temperature”? This term refers to the temperature difference between the leaving process fluid and the entering service fluid. If air is cooled from 300 F to 100 F using 90 F cooling water, the air temperature approaches the water by 10 F (100 – 90 = 10).

What is the importance of heat exchanger?

The heat exchanger is designed to provide the required amount of thermal energy needed for either heating or cooling a fluid stream in the process. The rate of heat transfer is important for the selection of a particular type of heat exchanger.

What are the requirements of heat exchanger?

Though cost is often the primary criterion, several other selection criteria are important:

• High/low pressure limits.
• Thermal performance.
• Temperature ranges.
• Product mix (liquid/liquid, particulates or high-solids liquid)
• Pressure drops across the exchanger.
• Fluid flow capacity.
• Cleanability, maintenance and repair.

How do you calculate MDMT?

The ASME Code requires this be determined for every pressure vessel and the MDMT be stamped on the nameplate. While every pressure vessel has its own unique MDMT, this may or may not be the MDMT that is stamped on the nameplate.

What is the design temperature of a heat exchanger?

In heat exchanger, there are two type of temperatures we deal with. One is design temperature (of shell side and tube side) and Tube metal temperature. Design temperature is the temperature which the exchanger tube or shell can withstand at operating pressure without creep failure.

What is a shell and tube heat exchanger?

Shell and tube heat exchanger is used for distallation columns, boilers, evaporators and other heavy-duty high temperature and pressure chemical processes. A shell and tube exchanger can handle very high temperature even at 1000 degrees Celsius.

What is the difference between designdesign temperature and tube metal temperature?

Design temperature is the temperature which the exchanger tube or shell can withstand at operating pressure without creep failure. The design temperature basically comes under mechanical design. Tube metal temperature (TMT) is more of process design interest.

What is TMT temperature in heat exchanger?

Tube metal temperature (TMT) is more of process design interest. When the exchanger handles heat sensitive material or material that is prone to decomposition or precipitation at high temeratures, control on TMT is important besides control on the bulk fl In heat exchanger, there are two type of temperatures we deal with.