Even the plate heat exchanger will have problems in the course of one year, requiring repairs, especially its seals, to see if it has loosened. This paper introduces the points for attention in the maintenance of plate heat exchangers.

    Plate heat exchanger is an important component of heat exchange technology in equipment of process industry. An elastomeric gasket (see Table 1) sealed between each plate is a vulnerable part and is also an easy ageing part under natural conditions. Its service life has an important influence on the service life of plate heat exchangers. If the seals are hardened and the original elasticity is lost, the heat exchanger will not work properly.

     The following factors have an important bearing on the service life of an elastic gasket:

        How does the heat exchanger work (continuous or discontinuous)

        The heat dissipation of the medium and the use of detergents are corrosive

        Maximum operating temperature

       Maximum work pressure

       The stress of the elastomeric gasket is greater due to excessive pressure and uneven pressure

       Natural aging

    The softening of an elastic gasket is related to pressure and temperature. When the gasket loses its elasticity, the heat exchanger will drip. In some of the products, in order to solve the leakage phenomenon caused by the aging of the gasket, allowing the heat exchanger sealing performance adjustment, namely again combined heat exchanger tightening bolt, pressing force adjusting each heat exchanger between the elastic sealing pad, solve the leakage problem. The maximum and minimum stresses are allowed on the plates of heat exchangers with this function. For the new heat exchanger sheet group, the minimum allowable stress shall be used to secure the connection. As each film heat exchanger number can be one or more times to adjust the heat exchanger tightening force, every time when tightening the nut can be screwed in the 3mm, and in the process of tightening the adjustment sheet always pay attention to the stress, and is only allowed to heat exchanger without working pressure, tightening force under the condition of room temperature adjustment, prevent leakage.

    There is no heat exchanger produced the stress range of adjustment in the nameplate, general stress values are given in the drawing, in this kind of screw plate heat exchanger, tightening torque in any case should not be less than the numerical drawing, because the assembly quality, assembly and deformation of plate heat exchanger. When the tightening torque reaches the required numerical value, the elastomeric gasket can be replaced by a planned method. There is a spare set of seals for plate heat exchangers used in important production equipment and corrosive medium. When the warehouse temperature is 18 degrees centigrade, the seal of the plate heat exchanger can be stored for about 3 years in the transparent plastic package.

     Fixed seal

    In principle, the seals are divided into two categories: bonding, fixing and non bonding. The shape of the gasket shall be consistent with the shape of the plate seal. It must be pointed out that the bonding method does not have any effect on the sealing function.

    Non-adhesive sealing
        ■ Alignment: place the sealing ring in place
        ■ Put in: make the sealing ring enter the sealing groove properly
      ■ Compression: in the sealing groove, there is a groove structure with a decreasing cross section so that the sealing ring can be correctly positioned

     Adhesive seal
    According to the use purpose and seal quality of the seal pad, the mixed sealant and non-harmonizing sealant can be used for different manufacturers. Prior to adhesion, steam airflow should be used to thoroughly remove residual adhesives and residual gaskets. The residual adhesive and residual seal on the surface of the plate heat exchanger must be used with fire. Adhesive in large quantities, should be ready to seal the liquid nitrogen pools, frozen ready for plate heat exchanger with gasket is dry processing furnace, heating temperature should be up to 160 ℃, if there are conditions, dealing with the plate heat exchanger for chemical cleaning, to ensure that thoroughly remove residues in the plate heat exchanger in combination with surface adhesion of the gasket.

    It is possible to know whether the sealing pad is installed correctly according to the observation hole of the bee room of the plate heat exchanger.

     A chemical cleanser should be used for the combination of plate heat exchanger (e.g., acetone). Also, chemical cleaners must be used to remove the softeners and adhesion coatings that are adhered to the sealing gaskets. Apply the adhesive to the middle of each bonding surface. Depending on the width of the seal pad, the width of the binder is about the width of a match, and then apply the adhesive to the whole surface of the adhesive to make full use of the whole bonding surface. Depending on the type of binder for certain ventilation drying time, and then into the seal, will each plate heat exchanger stacked together, tighten the screw tighten, or stacked with heavy pressure on the heat exchanger group. Depending on the type of adhesive, the hardening time is approximately 8 ~ 20 hours. For harmonic adhesives, screw tightening and heating hardening are necessary.

The main steps of the replacement of rubber parts are:

This station label: guangzhou force and, force and heat exchanger, force and plate heat exchanger, spiral plate heat exchanger