What are the anti-vibration measures for shell-and-tube heat exchangers?

What are the anti-vibration measures for shell-and-tube heat exchangers?

Shell-and-tube heat exchangers have good heat transfer efficiency and are not prone to structural issues during use. Additionally, the equipment has a compact, small, and lightweight structure.

If it is necessary to reduce the vibration of shell-and-tube heat exchangers, some measures need to be taken, such as changing the flow velocity of fluids, or installing sound insulation boards, etc.

High heat transfer efficiency
Due to the use of corrugated tubes as heat exchange tubes, the cross-section of the flow channel inside the tubes changes continuously and abruptly. This causes the fluid to remain in a state of high turbulence even at very low flow rates, making it difficult to form laminar flow. As a result, the main thermal resistance of convective heat transfer is effectively overcome. Heat transfer both inside and outside the tubes is enhanced simultaneously, so the heat transfer coefficient is very high, generally 2-3 times that of traditional shell-and-tube heat exchangers.

Strong stress compensation capability
Due to the structural shape and thin tube wall of corrugated tubes, when the temperature difference stress between the tube side and the shell side is large, the curvature of the corrugated tubes with elastic characteristics undergoes microcosmic changes to compensate for and eliminate thermal stress. This effectively prevents phenomena such as easy cracking of heat exchange tubes in traditional shell-and-tube heat exchangers.

Strong anti-scaling ability
Because of the high turbulence of the fluid in the flow channel, it is difficult for particles in the fluid to deposit and form scales. Even if a small amount of scale is formed, the medium flows turbulently inside and outside the tubes, which strongly scours the tube wall, resulting in strong anti-scaling ability.

Compact structure, small and lightweight
Due to the very high heat transfer coefficient of the corrugated tube heat exchanger, the required heat exchange area is small. Moreover, the wall thickness of the corrugated tubes is relatively thin. Therefore, the corrugated tube heat exchanger has a compact structure, being both small and lightweight.

Reduce the flow velocity of shell-side fluid
When the natural frequency of the heat transfer tube is fixed, reducing the shell-side flow velocity can avoid exciting resonance, but this is often not allowed in production operations. If the operating conditions cannot be changed, anti-impact plates, guide cylinders, or liquid outlet distributors can be designed at the inlet and outlet pipes of the heat exchanger to reduce the flow velocity at the shell-side inlet and outlet, minimizing the fluid pulsation value.

Increase the natural vibration frequency of the tubes
Increasing the natural vibration frequency of the tubes can greatly reduce the chance of resonance. The most effective way to increase the frequency is to reduce the span- the natural frequency of the tube is inversely proportional to the square of the span. If the span is shortened by half, the natural frequency will increase by about three times. For example, if the span is reduced by 1/3, the natural frequency can be increased by 50%.

Install sound-absorbing baffles
Installing longitudinal baffles parallel to the tube axis in the shell side can effectively reduce noise. The position of the baffles should be away from the standing wave nodes and close to the wave antinodes.

Mitigate the impact of periodic vortices
Winding metal wires circumferentially on the outer surface of the tubes or arranging metal strips along the axis can weaken the impact of periodic vortices and reduce the alternating force acting on the tubes.

GNEE was founded in 2008 and is located at No.4-1114, Beichen Building, Beicang Town, Beichen District, Tianjin, China. It is an entity enterprise engaging in high-end industrial equipment manufacturing, focusing on the R&D, manufacturing and related technical services of industrial heat exchange equipment and pressure vessels.​

Since its establishment, the company has adhered to the philosophy of "achieving customers, making employees happy; embracing changes, valuing actions; there is no best, only better". With the goal of providing one-stop services to make choices easier, it has been deeply engaged in industrial heat exchange equipment for many years and has become an excellent and irreplaceable presence in the industry.

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