Shell and Tube Heat Exchanger

Shell and tube heat exchanger consist of a series of stainless steel tubes. 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. A set of tubes is called the tube bundle and can be made up of several types of tubes: plain, longitudinally finned, etc. Shell and Tube heat exchanger are typically used for high pressure applications (with pressures greater than 30 bar and temperature greater than 260°C.This is because the shell and tube heat exchangers are robust due to their shape.

There are several thermal design features that are to be taken into account when designing the tubes in the shell and tube heat exchanger. These include:

Tube diameter: Using a small tube diameter makes the heat exchanger both economical and compact. However, it is more likely for the heat exchanger to foul up faster and the small size makes mechanical cleaning of the fouling difficult. To prevail over the fouling and cleaning problems, larger tube diameters can be used. Thus to determine the tube diameter, the available space, cost and the fouling nature of the fluids must be considered.

Tube length: heat exchangers are usually cheaper when they have a smaller shell diameter and a long tube length. Thus, typically there is an aim to make the heat exchanger as long as physically possible whilst not exceeding production capabilities. However, there are many limitations for this, including the space available at the site where it is going to be used and the need to ensure that there are tubes available in lengths that are twice the required length (so that the tubes can be withdrawn and replaced). Also, it has to be remembered that long, thin tubes are difficult to take out and replace.

Tube thickness: The thickness of the wall of the stainless steel tube is usually determined to ensure:

There is enough room for corrosion
That flow-induced vibration has resistance
Axial strength
Availability of spare parts
Hoop strength (to withstand internal tube pressure)
Buckling strength (to withstand overpressure in the shell)

Tube pitch: when designing the tubes, it is practical to ensure that the tube pitch (i.e., the centre-centre distance of adjoining tubes) is not less than 1.25 times the tubes' outside diameter. A larger tube pitch leads to a larger overall shell diameter which leads to a more expensive heat exchanger.

Tube corrugation: this type of tubes, mainly used for the inner tubes, increases the turbulence of the fluids and the effect is very important in the heat transfer giving a better performance.

Tube Layout: refers to how stainless steel pipe are positioned within the shell. There are four main types of tube layout, which are, triangular (30°), rotated triangular (60°), square (90°) and rotated square (45°). The triangular patterns are employed to give greater heat transfer as they force the fluid to flow in a more turbulent fashion around the piping. Square patterns are employed where high fouling is experienced and cleaning is more regular.

Baffle Design: baffles are used in shell and tube heat exchangers to direct fluid across the tube bundle. They run perpendicularly to the shell and hold the bundle, preventing the tubes from sagging over a long length. They can also prevent the tubes from vibrating. The most common type of baffle is the segmental baffle. The semicircular segmental baffles are oriented at 180 degrees to the adjacent baffles forcing the fluid to flow upward and downwards between the tube bundle. Baffle spacing is of large thermodynamic concern when designing shell and tube heat exchangers. Baffles must be spaced with consideration for the conversion of pressure drop and heat transfer. For thermo economic optimization it is suggested that the baffles be spaced no closer than 20% of the shell’s inner diameter. Having baffles spaced too closely causes a greater pressure drop because of flow redirection. Consequently having the baffles spaced too far apart means that there may be cooler spots in the corners between baffles. It is also important to ensure the baffles are spaced close enough that the tubes do not sag. The other main type of baffle is the disc and donut baffle which consists of two concentric baffles, the outer wider baffle looks like a donut, whilst the inner baffle is shaped as a disk. This type of baffle forces the fluid to pass around each side of the disk then through the donut baffle generating a different type of fluid flow.

Stainless Steel Tubing, Nickel Alloy Tubing, Brass Alloy Tubing, Copper Nickel Pipe Material Grades
Austenitic Austenite Stainless Steel SUS 304 S30400 Stainless Steel Tubing Tubes Pipe 304L S30404 Stainless Steel Tubing Tubes Pipe SUS 304H S30409 Stainless Steel Tubing Tubes Pipe 304NG Stainless Steel S30432 Super 304H Stainless Steel Tubes SUS 305 Stainless Steel Tubing Tubes Pipe Manufacturer SUS 309S S30908 Stainless Steel Tubing Tubes Pipe 310S S31008 Stainless Steel Tubing Tubes Pipe 316 S31600 Stainless Steel Tubing Tubes Pipe 316L S31603 Stainless Steel Tubing Tubes Pipe 316Ti S31635 Stainless Steel Tubing Tubes Pipe S31700 317LStainless Steel Pipe SUS 321 S32100 Stainless Steel Tubing Tubes Pipe SUS 321H S32109 Stainless Steel Tubing Tubes Pipe 347 S34700 Stainless Steel Tubing Tubes Pipe 347H S34705 Stainless Steel Tubing Tubes Pipe 253MA S30815 Stainless Steel Tubing Tubes Pipe 353MA S35315 Tubing Tubes Pipe ASTM A564 A693 630 S17400 Stainless Steel Tubing Tubes Pipe Super-Austenitic Stainless Steel 904L N8904 Stainless Steel Tubing Tubes Pipe 254 SMo S31254 Stainless Steel Tubing Tubes Pipe Duplex Stainless Steel S32101 Stainless Steel Tubing Tubes Pipe 2205 Duplex Pipe S32205 SA789 A789 S31803 Stainless Steel Tubing Tubes Pipe S32304 Stainless Steel Tubing Tubes Pipe manufacturer	2507 Super Duplex Steel S32750 Stainless Steel Tubing Tubes Pipe S32760 Stainless Steel Tubing Tubes Pipe Ferritic Ferrite Stainless Steel ASTM A268 405 S40500 Stainless Steel Tubing Tubes Pipe ASTM A268 409 S40900 Stainless Steel Tubing Tubes Pipe ASTM A268 430 S43000 Stainless Steel Tubing Tubes Pipe Manufacturer Martensitic Martensite Stainless Steel ASTM A268 410 S41000 Stainless Steel Tubing Tubes Pipe ASTM A268 410S S41008 Stainless Steel Tubing Tubes Pipe Manufacturer AISI 416 Stainless Steel Tubing Tubes Pipe AISI 420 S42000 Stainless Steel Tubing Tubes Pipe EN 10269 EN10302 1.4913 X19CrMoNbVN11-1 EN 10269 EN10302 1.4938 X12CrNiMoV12-3 Incoloy Alloy Tubing A286 Nickel Alloy Tubing Nickel Alloy 20 N08020 Nickel Alloy Tubing Tubes Pipe Incoloy 800 N08800 Nickel Alloy Tubing Tubes Pipe Incoloy 800H N08810 Nickel Alloy Tubing Tubes Pipe Incoloy 800HT N08811 Nickel Alloy Tubing Tubes Pipe Incoloy 825 N08825 Nickel Alloy Tubing Tubes Pipe Incoloy 901 N09901 Nickel Alloy Tubing Tubes Pipe Incoloy 925 N09925 Nickel Alloy Tubing Tubes Pipe Incoloy 926 N08926 Nickel Alloy Tubing Tubes Pipe Stockholder Inconel Alloy Tubing Inconel 600 N06600 Nickel Alloy Tubing Tubes Pipe Inconel 601 N06601 Nickel Alloy Tubing Tubes Pipe Inconel 625 N06625 Nickel Alloy Tubing Tubes Pipe Inconel 706 N09706Nickel Alloy Tubing Tubes Pipe Inconel 718 N07718 Nickel Alloy Tubing Tubes Pipe Inconel X-750 N07750 Nickel Alloy Tubing Tubes Pipe	Hastelloy Alloy Tubing Hastelloy B N10001 Nickel Alloy Tubing Tubes Pipe Manufacturer Hastelloy B2 N10665 Nickel Alloy Tubing Tubes Pipe Hastelloy B3 N10675 Nickel Alloy Tubing Tubes Pipe Supplier Hastelloy C4 N06455 Nickel Alloy Tubing Tubes Pipe Hastelloy C22 N06022 Nickel Alloy Tubing Tubes Pipe Supplier Hastelloy C276 ASTM B622 N10276 Nickel Alloy Tubing Tubes Pipe Hastelloy X N06002 Nickel Alloy Tubing Tubes Pipe Factory Hastelloy G Nickel Alloy Tubing Tubes Pipe Hastelloy G3 N06985 Nickel Alloy Tubing Tubes Pipe Nimonic Alloy Tubing Nimonic 75 N06075 Alloy Tubing Tubes Pipe Nimonic 80A N07080 Alloy Tubing Tubes Pipe Nimonic 90 N07090 Alloy Tubing Tubes Pipe Suppliers Monel Nickel Alloy Tubing Alloy 200 N02200 Nickel Alloy Tubing Tubes Pipe Alloy 201 N02201 Nickel Alloy Tubing Tubes Pipe Monel 400 N04400 Nickel Alloy Tubing Tubes Pipe Monel 401 N04401 Nickel Alloy Tubing Tubes Pipe Manufacturer Monel R 405 N04405 Nickel Alloy Tubing Tubes Pipe Monel K 500 N05500 Nickel Alloy Tubing Tubes Pipe Exporter Brass Alloy Seamless Tubing Tube Pipes C28000 Brass Alloy Seamless Tubing Tube C44300 Brass Alloy Seamless Tubing Tube C68700 Brass Alloy Seamless Tube Tubing Copper Nickel Alloy Pipe C70600 Copper Nickel Pipe C71500 Copper Nickel Pipe