Heat exchangers and types

selection and types

1. HEAT EXCHANGERS A piece of equipment built for efficient heat transfer from one medium to another.

2. Introduction A  heat exchanger  is a piece of equipment built for efficient heat transfer from one medium to another. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing and sewage treatment.

3. Flow Arrangement  In  parallel-flow  heat exchangers, the two fluids enter the exchanger at the same end, and travel in parallel to one another to the other side.

4. Flow Arrangement  In  counter-flow  heat exchangers the fluids enter the exchanger from opposite ends. The counter current design is the most efficient.

5. Flow Arrangement In a  cross-flow  heat exchanger, the fluids travel roughly perpendicular to one another through the exchanger.

6. Types Of Heat Exchangers Double pipe heat exchanger Shell and tube heat exchanger Plate heat exchanger Plate and shell heat exchanger Adiabatic wheel heat exchanger Plate fin heat exchanger Pillow plate heat exchanger Fluid heat exchangers Waste heat recovery units Dynamic scraped surface heat exchanger Direct contact heat exchangers HVAC air coils Spiral heat exchangers

7. Types Of Heat Exchangers Double pipe heat exchanger Shell and tube heat exchanger Plate heat exchanger Plate and shell heat exchanger Adiabatic wheel heat exchanger Plate fin heat exchanger Pillow plate heat exchanger Fluid heat exchangers Waste heat recovery units Dynamic scraped surface heat exchanger Direct contact heat exchangers HVAC air coils Spiral heat exchangers

8. Double Pipe Heat Exchanger It is also known as concentric tube heat exchanger In this heat exchanger the fluid to be cooled or heated passes through the tube 2(green) and the other fluid is passed through tube 1 (red)to absorb or release the heat. Advantages: Cheap for both design and maintenance. Disadvantages: Low efficiency and requires large space.

9. Double Pipe Heat Exchanger Applications Pasteurization Digester heating Heat recovery Pre-heating Effluent cooling.

10. Shell And Tube Heat Exchanger  One set of these tubes contains the fluid that must be either heated or cooled. The second fluid runs over the tubes that are being heated or cooled so that it can either provide the heat or absorb the heat required. They are typically used for high pressure applications.(above 30 bars)

11. Types Of Shell Tube Heat Exchangers

12. Shell And Tube Heat Exchanger Application Cooling of hydraulic fluid. Cooling of engine oils. Cool or heat swimming pool water or charged air.

13. Plate Heat Exchanger It is composed of multiple, thin, slightly separated plates that have very large surface areas and fluid flow passages for heat transfer. The plates are often spaced by rubber sealing gaskets which are cemented into a section around the edge of the plates. The plates are pressed to form troughs at right angles to the direction of flow of the liquid which runs through the channels in the heat exchanger. These troughs are arranged so that they interlink with the other plates which forms the channel with gaps of 1.3–1.5 mm between the plates.

14. The plates can be replaced after getting corroded. If the temperature difference to be accquired is to be increased then it can be done by adding more plates.

15. Plate Heat Exchanger applications Water heaters Cooling tower isolation Free cooling Waste heat recovery Heat pump isolation Thermal (ice) storage systems

16. Spiral Heat Exchanger A spiral heat exchanger (SHE), may refer to a helical (coiled) tube configuration Efficient use of space. They can be easily cleaned. A Spiral Heat Exchangers (or SHE) is a coiled tube arrangement, with two channels coiled one around the another. These two channels operate in a counter-flow arrangement, offering excellent turn down ratios, while optimising flow patterns which in turn, enhance heat transfer.

17. Spiral Heat Exchanger Application Pasteurization Recuperators (Exhaust and Air Handling Systems) Sludge Treatment (Thermal depolymerisation )

18. Selection Cost 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 Materials required for construction Ability and ease of future expansion

19. Maintenance Plate heat exchangers must be disassembled and cleaned periodically. Tubular heat exchangers can be cleaned by such methods as acid cleaning, sand blasting, high-pressure water jet, bullet cleaning, or drill rods. In large-scale cooling water systems for heat exchangers, water treatment such as purification, addition of chemicals, and testing, is used to minimize fouling of the heat exchange equipment. Other water treatment is also used in steam systems for power plants, etc. to minimize fouling and corrosion of the heat exchange and other equipment.

20. Thank you Presented By:- Devidas Barge Pratik Dalvi Gopesh Chilveri Aniket Dupade