The plate and frame heat exchanger is a welded plate heat exchanger without sealing gaskets between the plates, which can form a large heat transfer area in a highly compact space. The reasonable setting of the process ensures a reasonable match between the heat transfer efficiency of the equipment and the resistance loss. The shell adopts a hexahedral detachable structure, which can also meet the process requirements of mechanical cleaning and chemical cleaning inside the equipment. If the plate and frame fully welded heat exchanger does not meet the process requirements, we should check whether the original design parameters, design calculations, and assembly are correct, and then decide whether to increase or decrease the heat exchange area of the plate and frame fully welded heat exchanger and change the process combination. If the plate-and-frame all-welded heat exchanger starts to operate normally, it will deviate from the process requirements after a period of operation: the pressure drop increases or decreases; the medium outlet temperature increases or decreases. The way to deal with this failure is:
(1) Please check whether the inlet parameters of the cold and heat medium of the plate and frame fully welded heat exchanger are consistent with the original design value. If it does not match, try to adjust to the original design value. If the inlet parameters have been changed and cannot be adjusted to the original design value, the design calculation should be re-conducted and the heat exchange area of the plate and frame fully welded heat exchanger should be increased or decreased or the process combination should be changed.
(2) If the inlet parameters of the cold and hot media are consistent with the original design values, but the outlet parameters cannot reach the design values. The plate and frame fully welded heat exchanger should be shut down, and the plate and frame fully welded heat exchanger should be disassembled to check whether there is any blockage or plate fouling between the plates, and deal with it in time.