Evaporator hammering
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Horizontal evaporator, negative pressure of -8 kPa, temperature of 150°C, feed temperature of 78°C. The feed pipeline keeps making hammering noises; the feed valve is located on the evaporator, and the vibration is quite intense. I don’t know how to make adjustments to eliminate this hammering sound
It should be a liquid-phase feed; the feed must be introduced below the liquid level.
1. The description is really too detailed. 2. Is your heating medium steam? It may be that the steam trap system is not functioning properly, which causes vibrations to be transmitted to the feed valve.
Is it continuous feeding? Continuous feeding is likely caused by improper setup of the feed inlet – for example, it being placed below the liquid level, the pipeline being too thick, resulting in a high flow rate and fast feeding, etc.
Obviously, it is due to the two-phase flow. “Negative pressure of -8 kPa, temperature of 150°C, feed temperature of 78°C. Two-phase flow occurs behind the valve, resulting in vibrations; this is not greatly affected by the position of the feed pipe’s outlet. The following solutions can be considered: 1. Reduce the feed temperature: change it from 78°C to 60°C and observe the operational results. 2. Evaluate the control valve to determine whether its normal opening degree is appropriate. 3. Reduce the diameter of the pipe downstream of the control valve. 4. Calculate the effects of two-phase flow and vibrations
Upstairs is correct; the liquid has flashed.
Two simple methods to check if it can be solved: 1) Place the feed inlet below the liquid level； 2) Add a distributor at the feed inlet ；
When the material enters the negative-pressure area, its boiling point decreases; this may lead to rapid vaporization on a large scale, resulting in flashing and significant vibration of the equipment.
Obviously, it is due to the two-phase flow. “Negative pressure of -8 kPa, temperature of 150°C, feed temperature of 78°C. Two-phase flow occurs after the valve, resulting in vibrations; this is not greatly affected by the position of the feed pipe’s outlet. The following solutions can be considered: 1. Reduce the feed temperature from 78°C to 60°C and observe the operational results. 2. Evaluate the control valve to determine whether its normal opening degree is appropriate. 3. Decrease the diameter of the pipe downstream of the control valve. 4. Calculate the effects of two-phase flow and vibrations. Does the original poster have any data on these aspects? I hope the original poster can provide some assistance; thank you
Reply to 8# zhao*ao*ng: It’s obviously due to the two-phase flow. “Negative pressure of -8 kPa, temperature of 150°C, feed temperature of 78°C. Two-phase flow occurs after the valve, resulting in vibrations; this is not greatly affected by the position of the feed pipe’s outlet. The following solutions can be considered: 1. Reduce the feed temperature from 78°C to 60°C and observe the operational results. 2. Evaluate the control valve to determine whether its normal opening degree is appropriate. 3. Decrease the diameter of the pipe downstream of the control valve. 4. Calculate the effects of two-phase flow and vibrations. Does the original poster have any data on these aspects? I hope the original poster can provide some assistance; thank you
Reply to 5# jlchina: It’s obviously due to the two-phase flow. “Negative pressure of -8 kPa, temperature of 150°C, feed temperature of 78°C. Two-phase flow occurs after the valve, resulting in vibrations; this is not greatly affected by the position of the feed pipe’s outlet. The following solutions can be considered: 1. Reduce the feed temperature from 78°C to 60°C and observe the operational results. 2. Evaluate the control valve to determine whether its normal opening degree is appropriate. 3. Decrease the diameter of the pipe downstream of the control valve. 4. Calculate the effects of two-phase flow and vibrations. Does the original poster have any data on these aspects? I hope the original poster can provide some assistance; thank you