Plate Heat Exchanger Troubleshooting Plate Heat Exchanger Common Failure Analysis and Solutions
Cause analysis and solution of plate heat exchanger failures
I. Leakage between the plate and the frame or outside the frame
Leakage at the joint: Loosen the interface parts and check from the outside. If no fault can be found, please disassemble the heat exchanger and find the fault.
Cause analysis: 1. There is a gap (corrosion) in the joint part of the end piece hole; 2. The sealing part of the joint part is dislocated; 3. The joint part is distorted by the force of the pipe; Hole (corrosion).
Solution: 1. Change the joint; 2. Fix the sealing ring; 3. Hold up the pipe; 4. Change the sealing gasket; 5. Change the end piece.
Second, leakage between plates
Mark the leakage area between the two plates, disassemble the heat exchanger to determine the leakage location (through the spots) ) The sealing gasket is not damaged and gradually loosened, and the sealing gasket is not dislocated.
Cause analysis: 1. The sheet group was clamped too far, causing damage to the gasket groove; 2. The gasket was dislocated; The plate is placed upside down; 6. The slotted hole of the gasket means the double-layer seal is corroded; 7. The gasket is cracked or worn, aged, and corroded.
Solutions: 1. Change single and multi-piece; 2. Re-bond the gasket; 3. Change the plate; 4. Re-clamp; 5. Change the plate; Change the gasket.
Three, internal leakage between media
It means that the two media in the heat exchanger have leaked from the high-pressure side medium to the low-pressure side for some reason . The method of detecting leakage is to test the low-pressure side medium frequently and judge from the change of its composition. Shutdown inspection method: 1. Disassemble the frame, scrub the plates, observe and inspect the missing pieces (light transmission, coloring, visual inspection, etc.); The side of the plate that should not have water can be judged to have cracks in the plate.
Solution: Change single or multiple sheets, clean single or multiple sheets, and replace sealing gaskets.
Four. Low heat exchange efficiency
That is, low flow rate and high pressure drop The signs are as follows: 1 Pressure drop problem (note that Low flow rate, caused by high pressure drop); 2 Heat exchange efficiency problem: that is, normal flow rate.
1. The problem of pressure reduction; 2. The problem of heat exchanger efficiency: measure the inlet and outlet temperature and flow rate, and measure 6 times at 10 minutes interval for each measurement, and change the measurement points of each measurement group in sequence.
Cause analysis: 1. Internal blockage; 2. Flow tank blockage; 3. Side flow caused by incorrect placement of plates; 4. Slow circulation (flow) due to strong medium viscosity; 6 Plate fouling; 7 Bypass flow caused by incorrect placement of plates; 8 Actual data is different from the calibration data; 9 The flow rate is different from the calibration value; 10 Failure during condensation can be caused by non-condensable gas vapor The dryness is too low, the condensing steam arch valve or the weather is too low, the steam control valve is faulty; 11 There is gas in the heat exchanger; 13 There is a problem with the system design.
Solution: 1. Disassemble the heat exchanger to clean the interior; 2. Disassemble the interface to clean the outlet; 3. Rearrange the plates; 4. Re-select or adjust the working conditions; 5. Exclude non-condensed gas; 6. Disassemble the heat exchanger and clean the plate to change the plate arrangement; 7. Change the flow rate or requirement; 8. Exhaust gas and replace the condensate discharge valve or air pump to replace the steam control valve; 9. Modify the system.
