31 Shell And Tube Heat Exchanger- An Overview

In this article we will study details about shell and tube heat exchanger , how to prepare data sheet for heat exchanger , components of heat exchanger and application for it and much more.

Shell and tube Heat exchanger

As a Chemical it is necessary to have knowledge of design of shell and tube Heat exchangers. Some of design company use software for design of Shell and tube Heat exchanger. There are lot of software are available in market like , HTRI , Aspen Hysis and more . We will study design of shell and tube Heat exchanger by trail and error method . Before to study trail and error method we need to know about components of heat exchanger. So we will start this article with different components of a typical heat exchanger.

Components of heat exchanger

• Tube
• Tube sheet
• Baffles
• Shell
• Shell Cover
• Spacer
• Support
• Pass partition

Tubes

Tube is main part of a typical shell and tube Heat exchanger . Area of heat exchanger is depends on how much number of tubes , What is diameter of tubes ? To design a tube of HE we need to identify required MOC of tube , schedule of tube , Seamless or ERW ? , What is pressure rating of tube ? What is temperature rating of tube ? Length of tube , diameter of tube .

Before to consider above point first we need to decide Process side or utility side . You can think on following points before to decide Process and utility side .

• Carosiveness of Process side
• If utility is steam or heating medium then you can use utility in shell side
• If utility is water , brine or chilled water then you can use utility in tube side .

Tube sheet

Tube sheet is a sheet which hold the all tubes with a perticular distance between two tubes . We need select the MOC and thickness of Tube sheet as per our requirement. To choose MOC we should have knowledge about process parameters like pH value , temperature and pressure rating.

Shell

Another most important part of a shell and tube heat exchanger is its “Shell”. In different types of Condenser we use process in shell side . If our material is not carosive we can use material flow in shell side . We get some outer air cooling in shell and tube heat exchanger . We can choose MOC of shell like SS-316 , MS , CI etc.

Baffles

Unlike shell and tube baffles also play a important role in heat exchanger . Baffles are vanes or which play the role of giving direction and obstruction to the flow of liquid . Baffles also gives support to tube bundles. The main two roles of baffles are give directions and obstruction to flow and hold the tube bundles and give more heat transfer area to heat exchanger. In design of Shell and tube Heat exchanger we need decide baffles spacing and number of baffles also thickness and MOC of baffles. In technical data sheet of heat exchanger we need to put data like baffles spacing or number of baffles. To design a heat exchanger you should have knowledge of baffles . Hope above information is sufficient for you to gain some knowledge of baffles role in heat exchanger.

Shell Cover

Shell Cover is part of heat exchanging Equipments which cover the shell . It has Verius types . We need to select proper MOC of it as per process requment.

Pass Partition

Pass partition is partion wall or sheet which give direction to pass which results in increasing in number of pass . We need to show it in heat exchanging equipments to understand vendor how much number of pass and pass pattern.

Supports

On the basis of orientation whether horizontal or vertical we need decide type of support which is necessary for equipment. General in heat exchanging equipments we give saddle type and lug type support . Salection of support is depends upon hydraulic weigh or equipments also depends on orientation of equipment. If plant is Chemical not as per CGMP norms then we can choose MOC of support is CS. If we want a equipment as per CGMP norms then we can choose MOC of equipment is SS-304 .

applications of shell and tube heat exchanger

• It is use in distillaion as evaporator as a reboiler which play the role of boiling and evaporating crude material . For boiling and evaporating purpose we can use high pressure steam , low pressure steam , High Therm Oil as heating medium depending upon process requment.
• It is use as condenser , partiall condenser in distillaion column . Main role of it as a condenser is to condense the vapor in to liquid .
• In distillaion column it can used as sub-cooler . The main role of it is to cool the condensed liquid to a perticular temperature. For cooling purpose we can provide chilled water or cooling water to sub-cooler .
• In distillaion column it can used as pre-heater . Role of shell and tube Heat exchanger in it is pre-heat the feed material up to a perticular temperature. We can give condensed steam to it for pre-heating . Normally condensed water temperature is near about 99 Degree Celsius , so we can use it for pre-heating purpose .

how many times do we have to calculate for pressure drop in a shell and tube heat exchanger?

The number of times you need to calculate for pressure drop in a shell and tube heat exchanger depends on the specific design and operating conditions of the heat exchanger. Typically, the pressure drop in a shell and tube heat exchanger is calculated during the design phase and may be reevaluated during certain scenarios or when changes occur in the system.

Here are some key points when pressure drop calculations are typically performed:

1. Design Phase: During the initial design of the heat exchanger, engineers perform detailed calculations to determine the pressure drop in both the shell side and tube side. These calculations help ensure that the heat exchanger operates within the desired pressure limits and that it meets the process requirements efficiently.
2. System Changes: If there are significant changes in the operating conditions, such as flow rates, temperatures, or fluid properties, engineers may need to recalculate the pressure drop. For example, changes in the process flow rates or fluid properties could result in altered pressure drop characteristics.
3. Fouling and Maintenance: Over time, heat exchangers can accumulate fouling on the tube side and shell side surfaces, which can affect the pressure drop. Periodic maintenance or cleaning may be necessary, and after such procedures, pressure drop calculations might be performed to assess the heat exchanger’s efficiency.
4. Troubleshooting: In the event of performance issues or unexpected problems in the heat exchanger, pressure drop calculations can help identify potential causes or inefficiencies.
5. Optimization Studies: In some cases, engineers may perform pressure drop calculations as part of optimization studies to improve the heat exchanger’s overall performance or efficiency.

The frequency of pressure drop calculations depends on the specific application, industry standards, and operational requirements. In critical processes or industries with strict safety regulations, regular pressure drop assessments may be mandated to ensure the heat exchanger’s reliable and safe operation. In other cases, occasional assessments during maintenance or system changes may be sufficient.

Conclusion

From above article it is clear that what are the main and key parts of shell and tube Heat exchanger , what is role of them in it , how to design them also what are the some Industrial applications of heat exchangers. If you want more information about it please comment we will try our best to give you a solution as per our time .

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Some External links

types of shell and tube heat exchanger

shell and tube heat exchanger working principle

shell and tube heat exchanger – wikipedia

shell and tube heat exchanger pdf

shell and tube heat exchanger manufacturers

shell and tube heat exchanger design

shell and tube heat exchanger calculations

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