29 Mar 2020

Treatment of Failure of Plate Heat Exchanger

29 Mar 2020

1 clean the sealing groove of plate heat exchanger

Sealing gasket plays a key role in all parts of plate heat exchanger. In most plate heat exchangers in China, paste the gasket into the gasket groove with adhesive, and finally form a "paste" closed framework [3]. Especially for BR02 plate heat exchanger, the adhesive between the bonding plate and the sealing gasket is 401 instant dry adhesive which is used to bond rubber and plastic. The bonding strength between BR02 plate heat exchanger and stainless steel plate is the most suitable. When replacing the gasket, first place the plate flat on the plate, then use a screwdriver to gently pry off the gasket and slowly tear it off. As for the residual adhesive in the gasket groove, stainless steel cleaning ball or wire brush shall be used in combination with acetone. After comprehensive brushing, water shall be used for washing.

2 disassembly and maintenance method of plate heat exchanger

For plate heat exchanger, according to the maintenance time and situation, personnel can be arranged to the site for disassembly and maintenance, or overall disassembly, hanging the corresponding position, and then disassembly and maintenance. Before disassembly and maintenance, carefully measure the clearance a between two pressing plates with a tape measure to facilitate standby. Secondly, use spanner to loosen fastening nuts evenly in order, and then remove the clamped screw. Finally, move the movable pressing plate to one end of the column, lift the plate, push the plate to the notch of the upper guide rod, and take out the plate with front or back tilt.

3. Method of disassembling plate heat exchanger

When removing and installing the plate heat exchanger, tighten the bolts evenly. During the installation of each bolt, check the length of each side of the plate. After the bolts are tightened by hand as far as possible, a special torque wrench shall be used to tighten the bolts according to the corresponding sequence until the bolts are fully tightened. Finally, according to the above steps, tighten the plate of the heat exchanger to the required length, and use a metal ruler to measure the length of the plate. It is forbidden to reinforce the plate heat exchanger during operation or under the pressure of filling medium. At the same time, make sure that the plate bundles are parallel in operation, so as to avoid the deformation of the plate, which leads to the sealing failure of the gasket of the heat exchanger. In case of leakage during the use of plate heat exchanger, tighten the bolts in time. If the leakage problem is not stopped, it is necessary to stop tightening the bolts and replace the leakage plate surface. When the plates are disassembled, the plates with hot and cold medium shall be disassembled together.

4. Chemical flushing method

Compared with stainless steel plate heat exchanger, it is forbidden to use hydrochloric acid or hydrochloric acid substances, such as cleaning powder, cleaning agent, etc., to carry out chemical cleaning of residual dirt. It is particularly important to note that it is forbidden to dismantle the whole plate equipment for cleaning, because: these residual dirt is not completely dissolved, a few are still left in the structural gap, and cannot be cleaned. This will damage the machine.

In addition, the chemical cleaning of acid and alkali neutralization has not been fully developed. In order to solve this problem, we can choose the method of peach crisp detergent or nitric acid comprehensive inhibitor to wash, and adjust its temperature properly, which is beneficial to speed up its cleaning speed. Chemical cleaning method is less used in plate heat exchanger which is difficult to disassemble and clean.

All in all, plate heat exchanger is a kind of high-tech and advanced equipment with high efficiency. The method of disassembly and maintenance is helpful to find and solve the corresponding problems in time. However, due to the structural characteristics and maintenance requirements of plate heat exchanger, only careful and serious work can ensure the smooth completion of the maintenance process, so as to ensure the stable operation of plate heat exchanger.