FABRICATION OF HEAT EXCHANGERS
[EIRI/EDPR/1020] J.C.9659
INTRODUCTION
Heat exchangers are devices whose primary responsibility is the transfer (exchange) of heat, typically from one fluid to another. However, they are not only used in heating applications, such as space heaters, but are also used in cooling applications, such as refrigerators and air conditioners. Many types of heat exchangers can be distinguished from on another based on the direction the liquids flow. In such applications, the heat exchangers can be and be parallel-flow, cross-flow, or counter current. In parallel-flow heat exchangers, both fluid involved move in the same direction, entering and exiting the exchanger side by side. In cross-flow heat exchangers, the fluid paths run perpendicular to one another. In countercurrent heat exchangers, the fluid paths flow in opposite directions with each exiting where the other enters. Countercurrent heat exchangers tend to be more effective than other types of exchangers.
Aside from classifying heat exchangers based on fluid direction, there are types that vary mainly in their composition. Some heat exchangers are comprised of multiple tubes, whereas others consist of hot plates with room for fluid to flow between them. Its important to keep in mind that not all heat exchangers depend on the transfer of heat from liquid to liquid, but in certain cases use other mediums instead.
Types of Heat Exchangers
Shell and Tube Heat Exchanger
Shell and tube heat exchangers are comprised of multiple tubes through which liquid flows. The tubes are divided into two sets: the first set contains the liquid to be heated or cooled. The second set contains the liquid responsible for triggering the heat exchange and either removes heat from the first set of tubes by absorbing and transmitting heat away in essence, cooling the liquid or warms the set by transmitting its own heat to the liquid inside. When designing this type of exchanger, care must be taken in determining the correct tube wall thickness as well as tube diameter, to allow optimum heat exchange. In terms of flow, shell and tube heat exchangers can assume any of three flow path patterns.
Plate Heat Exchanger
Plate heat exchangers consist of thin plates joined together with a small amount of space between each plate, typically maintained by a small rubber gasket. The surface area is large and the corners of each rectangular plate feature an opening through which fluid can flow between plates, extracting heat from the plates as it flows. The fluid channels themselves alternate hot and cold fluids, meaning that heat exchangers can effectively cool as well as heat fluid they are often used in refrigeration applications. Because plate heat exchangers have such a large surface area, they are often more effective than shell and tube heat exchangers.
Regenerative Heat Exchanger
In a regenerative heat exchanger, the same fluid is passed along both sides of the exchanger, which can be either a plate heat exchanger or a shell and tube heat exchanger. Because the fluid can get very hot, the exiting fluid is used to warm the incoming fluid, maintaining a near constant temperature. A large amount of energy is saved in a regenerative heat exchanger because the process is cyclical with almost all relative heat being transferred from the exiting fluid to the incoming fluid. To maintain a constant temperature, only a little extra energy is need to raise and lower the overall fluid temperature.
Adiabatic Wheel Heat Exchanger
In this type of heat exchanger, an intermediate fluid is used to store heat, which is then transferred to the opposite side of the exchanger unit. An adiabatic wheel consists of a large wheel with threads that rotate through the fluids both hot and cold to extract or transfer heat.
COST ESTIMATION
Plant Capacity 30 Nos/Day
Land & Building (500 Mtr.) Rs. 57.50 Lac
Plant & Machinery Rs. 16.00 Lac
Working Capital for 3 Months Rs. 62.23 Lac
Total Capital Investment Rs. 1.46 Cr
Rate of Return 32%
Break Even Point 57%
CONTENTS
INTRODUCTION
USES AND APPLICATION
B.I.S. SPECIFICATIONS
MARKET SURVEY
PRESENT MANUFACTURERS/SUPPLIERS
SPECIFICATION OF HEAT EXCHANGER
B.I.S. FOR METAL JACKETED GASKET
MANUFACTURING PROCESS
PUNCH PRESS
PROCESS FLOW CHART
PLANT LAYOUT
SUPPLIERS OF RAW MATERIALS
SUPPLIERS OF PLANT AND MACHINERY
APPENDIX – A:
01. PLANT ECONOMICS
02. LAND & BUILDING
03. PLANT AND MACHINERY
04. OTHER FIXED ASSESTS
05. FIXED CAPITAL
06. RAW MATERIAL
07. SALARY AND WAGES
08. UTILITIES AND OVERHEADS
09. TOTAL WORKING CAPITAL
10. TOTAL CAPITAL INVESTMENT
11. COST OF PRODUCTION
12. TURN OVER/ANNUM
13. BREAK EVEN POINT
14. RESOURCES FOR FINANCE
15. INSTALMENT PAYABLE IN 5 YEARS
16. DEPRECIATION CHART FOR 5 YEARS
17. PROFIT ANALYSIS FOR 5 YEARS
18. PROJECTED BALANCE SHEET FOR (5 YEARS)
