Design And Analysis Of Heat Pipe Heat Exchanger For Stenter Machine

Abstract

Stenter machine is one of the well-known machine in textile industry. One of the process of Stenter machine is heat setting of the fabric which is done by combustion of natural gas, thermic oil, steam etc. The quality of the fabric is to be maintained and care is to be taken that the fabric is not stained by contaminated air or due to oil content in the system. Huge amount of gases are exhausted from the Stenter machine which can be as high as 3000 m3/hr. The exhaust gases can be in the temperature range of 80-200°C depending on the process and type of fabric. This high energy of the exhaust gases can be recovered and can be given to the fresh air so that the amount of fuel required to heat the fresh air taken for compensation of the exhaust air could be decreased and thus some amount of energy can be saved. The energy can be recovered from exhaust gases by using various types of air to air heat exchangers viz. heat pipe heat exchanger, shell and tube heat exchanger, plate fin heat exchanger etc. M/s InspirOn Engineering Private Limited, Odhav manufactures Stenter machine and uses typical design of air to air heat exchanger. In the present study, design of heat pipe heat exchanger as an alternate design for existing heat exchanger is presented. Heat pipe for heat pipe heat exchanger is designed and is checked for various limits viz. sonic limit check, entrainment limit check, boiling limit check, viscous limit check in extreme conditions of exhaust gases. As the application range of temperature is very wide (viz. 80-200°C) in exhaust gases, the heat pipe heat exchanger is designed for 200°C and is checked for working at 80°C. Depending on requirement 4 different options of heat pipe heat exchangers are proposed. To predict the performance of the heat pipe heat exchanger, the heat pipe is fabricated and experiments were performed at different flow rates and inclinations of heat pipe with electric heater as power input. The analysis was done by recirculating the water through heat exchanger, passing the water once through the heat exchanger as well as with stagnant water. The collection efficiency of heat pipe was obtained as 47-49% at different flow rates. The instantaneous efficiency of heat pipe was found in the range of 86-94% at different flow rates.