The tube sheet is a plate with drilled holes where the tubes are fixed either by welding or grooving to provide proper holding of tubes in the plate. The plate is welded to shell and provides partition to the shell side and tube side fluid.
When matter undergoes phase change (vapour to liquid, liquid to solid, solid to gas, etc.) the amount of heat associated with unit amount of matter either added or removed at constant temperature and pressure is known as latent heat of phase change. Sensible heat is the amount of heat that must be added or removed to raise or drop the temperature of a substance or mixture of substances.
When two fluids at different temperatures are brought into direct or indirect contact, the heat flows from a body at high temperature to that at lower temperature, this flow of heat is called as heat transfer.
Heat flux is defined as the rate of heat transfer per unit area. It is denoted by Q, the units of heat flux is kcal/hr.
The heat exchanger that is used to cool a fluid by means of a coolant (generally water) is termed as a cooler. It involves the removal of sensible heat from process fluids.
The heat exchanger, which is used to condense vapour or mixture of vapours in presence or absence of non-condensable gas, is termed as a condenser. The vapour condenses and changes its phase from gas to liquid. It involves the removal of latent heat with the help of suitable cooling media.
Approach temperature is the terminal point temperature difference between hot and cold fluids. For e.g. If Thi and ThO is inlet and outlet temperature of hot fluid and Tci and Tco is the inlet & outlet temperature of cold fluid then Thi –Tco is called as approach temperature.
A heat exchanger is an equipment that transfers heat from hot fluid to cold fluid.
The thermal designing is done with the help of specialised heat Exchanger design software developed by HRS group. The manufacturing of the unit is done by using various mechanical design standards like ASME Section VIII, Div (I), TEMA, etc.
The standard sizes available are Tubes diameter: 18mm, 19.05 mm (3/4”), 25.4mm (1” ) Length of tube: 1meter, 1.5 meter.2 meter, 3 meter, 4.5 meter, 6 meter, and 9 meter tube on customer request.
The main components of shell and tube heat exchanger are:
- Shell
- Tubes
- Tube sheet
- Bonnet or channel
- Baffles, Tie rods & Spacers
- Nozzle
- Saddle support
Heat exchangers are used for various operations in the industry for cooling, chilling, evaporation, condensation, heating, reboiling etc.