The GLB-200 shell and tube heat exchanger is suitable for steam-water, water-water, and other heat exchange conditions. The following Q&A is based on on-site operation and maintenance experience.
Check the shell for leakage, whether the flange connections are tight, and whether there is abnormal displacement of the supports. Observe the pressure gauge and thermometer readings. If the pressure difference between inlet and outlet increases by more than 0.05 MPa compared with the initial value, cleaning should be arranged. Record the secondary-side outlet temperature once a week. If the deviation exceeds ±5°C from the design value, the cause must be investigated.
When the metal wall temperature difference between the tube side and shell side exceeds the allowable range of the material, a fixed tubesheet structure will generate relatively large thermal stress. In this case, a floating-head or U-tube structure with expansion joints should be selected to absorb the thermal expansion difference. The GLB-200 shell and tube heat exchanger can use a fixed tubesheet under working conditions with a temperature difference of ≤50°C; when it exceeds this, the selection should be adjusted according to the above principle. During operation and maintenance, if cracks are found in the tubesheet welds, it is necessary to recheck whether the actual temperature difference has exceeded the limit.
According to the fouling coefficient of the medium, it is generally inspected every 3 to 6 months. If the pressure drop increases by 15% or the heat transfer coefficient decreases by 20%, cleaning should be carried out. During cleaning, avoid using high-concentration acid solutions to prevent corrosion of the tube bundle.
Drain the internal medium, fill with dry nitrogen for protection, or use full-water maintenance and regularly test the water quality. Apply anti-rust grease to the flange sealing surfaces.
