Knowledge base
The two workhorses for moving heat between liquids are the plate exchanger and the shell and tube exchanger. Both separate two circuits and both are found in engine rooms, power plants and process plants, but they are built differently and behave differently. This guide explains what each is, where each is the better choice, and the questions that decide between them.
Two Ways Of Building The Same Job
A plate exchanger is a pack of thin corrugated plates with the two liquids flowing in alternate narrow channels. A shell and tube exchanger is a bundle of tubes inside a cylindrical shell: one liquid runs through the tubes, the other around them. The plate type puts a large surface into a small volume; the tube type is a sturdier, simpler, larger construction.
Where The Plate Exchanger Wins
Compactness and efficiency. For the same duty a plate exchanger is smaller and lighter, holds less liquid, reacts faster to load changes and can bring the two liquids closer in temperature. Many designs can be extended with more plates, and the gasketed kind opens for cleaning. Where space is tight, as on a skid, a platform or inside a building, this is usually decisive.
Where Shell And Tube Wins
Toughness. A tube exchanger tolerates higher pressures and temperatures, dirtier liquids, gases and vapours, and rough operating conditions better than a plate unit with its narrow channels and gaskets. It is the usual choice for heavy industrial duties, for steam, for aggressive or fouling fluids and for very large duties. The price is size, weight and the space needed to pull the tube bundle out for cleaning.
How To Decide
Start from the fluids and the conditions, not the price. Clean, treated water or glycol at moderate conditions points to plates; fouling, gases, high pressure or high temperature point to tubes. Then ask how much space there is and whether the duty will grow. Plates are the answer more often than not in cooling circuits for engines and power plants, and tubes where the conditions rule plates out.
TECS Engineering designs and delivers plate heat exchanger solutions for engine, power plant and industrial cooling circuits. Send the fluids, the flows and temperatures and the conditions of the site, and the engineering team will answer.
In Short
- Plate: compact, efficient, quick; extendable and, in the gasketed kind, openable
- Shell and tube: robust, for higher pressure and temperature and for dirtier fluids
- Plates for clean liquids and tight space; tubes for harsh duty and large size
- Tube bundle needs room to be withdrawn for cleaning
- Decide from the fluids and the conditions first, the price second
- Most engine and power plant cooling circuits suit plates
What To Send With An Enquiry
- The two fluids and their cleanliness
- Heat duty, flows and temperatures
- Pressure and temperature on each side
- Space available and how the unit will be reached for cleaning
- Whether the duty may grow
- Site conditions and any material specification
Questions We Are Often Asked
Which is more efficient, plate or shell and tube?
The plate exchanger, because the plates give a large surface in a small volume and keep the liquids turbulent. It brings the two liquids closer in temperature for the same size.
Which handles dirty liquids better?
The shell and tube exchanger. Its wide passages and sturdy construction tolerate fouling and solids that would block the narrow channels of a plate unit.
Which takes less space?
The plate exchanger, usually by a large margin for the same duty.
Which can be extended later?
The gasketed plate exchanger, by adding plates within the limits of its frame. A tube exchanger is built to a fixed size.
Which is used for engine cooling circuits?
Plate exchangers are very common there because the circuits are closed and treated; shell and tube units are used where the conditions are harsher.
Contact Us
Send us the heat duty, the fluid temperatures and flow rates, the ambient conditions and the installation limits. We answer with a design proposal - or write to us on WhatsApp.
