Views:3 Author:Site Editor Publish Time: 2020-03-30 Origin:Site
In the process of daily use of plate heat exchangers, if we find that the equipment is faulty, we need to repair it in a timely manner. How can we repair the plate heat exchanger?
When removing the plate, make the plate skew to the side by 15 ° -20 °, and lift it upwards to remove it. Do not disassemble it forcibly to prevent the upper positioning groove from being deformed or damaged. Then follow the order of the piece device. The code is good. For severely deformed plates, aluminum or copper models can be used for correction. When looking at the heat exchanger plate, the plate should be free of defects such as cracks, scratches, deformation, etc. The uneven thickness error should not exceed 5%. The periphery of the plate should be lubricated and flat. The shape of the sealing groove should meet the requirements of the pattern, and its depth should allow for errors. It is 0.1mm, and its sealing surface does not allow defects such as bumps, wrinkles, distortions, scratches, etc. that affect the sealing function. The plate corrugation depth allows an error of ± 0.2mm, and its unevenness must not be greater than 1%. During the disassembly process, the offset of the width of the movable platen should not exceed 10mm, and the offset of the straight direction should not exceed 25mm. The movable platen should always be moved in parallel at all times.
Wait until the system gas, pressure, temperature and other parameters reach the repair requirements before entering the site construction. The adhesive used should also be within its useful life. For perforated plates, hydrogen arc welding can be used to repair and smooth them. Before disassembly, the medium inlet valve should be closed, and the high-pressure side valve should be closed first, then the outlet valve should be closed, the heat exchanger should be slowly cooled down to 40 ° C, and then discharged, and then the connected pipes should be removed and the whole can be lifted off. Therefore, it is also a plate heat exchanger. Because of its variety of methods, it can be applied to a wide range of fields and can be used in most heat exchange processes. If these shortcomings cannot be dealt with, the overhaul of the plate heat exchanger will collapse.
Because of the large number of plate heat exchangers and the need to arrange them one by one and replace all new pads, generally the orientation of the entire lifting device is selected during overhaul and collapsed and overhauled at a suitable location. When the scale on the plate is very thin and the scale layer is easily soluble in water, the plate can be placed in a special water tank and scrubbed with soft fiber brown hair. It can also be washed with 1-29cg / cmz of pressure water or low-pressure steam. Under no circumstances should the use of acetylene flame heating be stopped. Prior to maintenance, the gaskets to be replaced need to be carefully inspected. The appearance should be lubricated, the thickness is common, there are no transverse cracks, no bubbles, no nicks, no aging, no overlap and no traces of overlap. Remove the receiver first, and then loosen the fixing bolts in the diagonal direction. Remove the old gasket first.
The combination of various methods can meet the requirements of different working conditions, and is more targeted in application. One hand holds the electric hot air to heat the bottom of the sealing groove. When the adhesive is softened by the heat, the other hand pulls the mat up and slowly peels off. The entire heat exchanger collapsed. After the gasket is removed, the remaining glue in the sealing groove can be mounted on a tangential grinder with a stainless steel wire wheel with a diameter of 40-50mm and a width of 8-10mm, and the remaining glue can be removed to ensure that the sealing groove is smooth. For the heat exchanger body, remove the compression bolt protection sleeves and degrease all the bolts; check the sliding appearance of the upper beam and scrub it clean; check the upper roller of the movable platen to make it move sensitively; measure and stack Length "A", this dimension should be kept constant when reinstalling. Another example is the temperature and pressure resistance of the welded plate heat exchanger is significantly better than that of the detachable plate heat exchanger, which can reach 250 ° C and 2.5MPa. The plate heat exchanger can be divided into detachable, welded, brazed and other methods according to the assembly method; according to the ripples of the heat exchange plate, it can be divided into herringbone waves, flat waves, spherical waves, etc .; according to the gasket, it can be divided into Adhesive and hasp.