The mechanical expansion of spiral plate heat exchanger is to use the pressure of the ball of the tube expander to make the metal wall at the end of the tube subject to internal extrusion and expansion. When the metal of the outer wall of the tube and the hole wall of the tube plate deforms, the deformation of the tube is far greater than the deformation of the hole wall, so that the tube will have flow plastic deformation. When the tube expander is removed, the hole wall shrinks elastically. Hold the expanded part of the tube tightly, so that the tube is closely connected with the tubesheet. In order to make the pipe resistant to certain pulling stress, the extended part of the pipe can also be turned out of the bell mouth shape with the help of the flanging expander to prevent the pipe from being pulled out of the pipe hole during operation.

Inserting lath or rods at the tube gap of spiral plate heat exchanger to limit the movement of tubes can increase the natural vibration frequency of tubes. This method can prevent vibration in the U-shaped tube area of spiral tube heat exchanger. No tubes are arranged at the notch of baffle plate, so that each baffle plate can support tubes. Compared with the tubes in the spiral plate heat exchanger with baffles, the span of the tubes in the central part is shortened by one time, which greatly increases the natural frequency.

In addition, support plates can be set between baffles to further increase the rigidity of tubes without substantial influence on heat transfer and pressure drop. In addition, support plates can also be set between baffles of spiral plate heat exchanger to further increase the rigidity of tubes without substantial impact on heat transfer and pressure drop. Reducing the gap between tubes and baffle holes and thickening the baffle plate can not substantially change the natural vibration frequency of tubes, but can reduce the sawing effect of tube baffles and increase the damping of the system. If the baffle material is softer than the pipe, sometimes the damage can be reduced.