What should be noted when using a water-bath vaporizer?
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Water bath vaporizers are generally used to reheat liquid nitrogen produced by reciprocating low-temperature, high-pressure nitrogen pumps. The principle involves using high-temperature steam to exchange heat with the liquid nitrogen, with desalinated water being used in this process. Hot high-pressure nitrogen is obtained. However, in production, since high-pressure nitrogen is used in large quantities in subsequent processing steps, the operation of a single reciprocating high-pressure nitrogen pump is not sufficient to maintain the required pressure; therefore, two high-pressure nitrogen pumps are usually used together. With the operation of two nitrogen pumps, a large amount of liquid nitrogen enters the water bath vaporizer. So what is an appropriate temperature setting for the water bath vaporizer itself? Is a temperature of 50 to 60 degrees Celsius suitable? What are the potential hazards of setting the temperature of the water bath vaporizer too high? ? ?
The water-bath vaporizer, classified by heating method, belongs to the category of indirectly heated vaporizers. Based on their working principle, they can be further divided into \"steam-heated bath vaporizers,\" \"electrically heated bath vaporizers,\" and \"circular hot water bath vaporizers.\" In general, it involves heating the water in the vaporizer to heat the liquid gas flowing through it, thereby vaporizing it to meet the user’s requirements. Applicable media: liquefied natural gas LNG, liquefied petroleum gas LPG, liquid oxygen LO2, liquid nitrogen LIN2, liquid argon LAr, liquid carbon dioxide LCO2, and others. Vaporization capacity: 10~20,000 M3/h (per unit); higher vaporization rates can be achieved by using multiple units in parallel. Work stress:
The normal temperature is set between 60 and 65 degrees Celsius; setting the temperature of the water bath vaporizer itself too high should not cause any harm
A carburetor temperature of 50 to 60 degrees is a bit low; it’s usually 70 degrees or higher. However, the temperature shouldn’t be too high either, as that can have an impact on the internal pipes of the equipment!
If there is enough steam, setting it at 50 degrees will suffice, so that the outlet temperature can reach twenty to thirty degrees. During operation, none of the interlocks can be disabled; this type of pump has had problems, with the outlet pipeline freezing and cracking – this is something that must be taken into account. Also, monitor the water level in the evaporator at all times to ensure there is overflow.
When in use, the water temperature in a water-bath type vaporizer should not be too high; it should be kept around 60 degrees. This is because both the piping system and the pressure vessels have designated temperature limits, which are there to prevent damage to the equipment due to excessively high temperatures, as well as leaks caused by thermal expansion and contraction of the piping flanges； Also, be careful to prevent the water temperature in the water-bath type vaporizer from dropping too low, as this can cause frosting in the outlet pipes or even freezing and cracking of those pipes, thereby affecting normal operation ；
The temperature of the carburetor must be controlled in accordance with the specified limits. If the temperature is too high, energy is wasted; if it’s too low, care must be taken to prevent the carburetor from freezing. Some other units assumed that the readings regarding the carburetor temperature were inaccurate and ignored them, resulting in the carburetors freezing up, which took several days to thaw.
The temperature here is around 50 degrees, but the operation must be carried out slowly. In case of an emergency, the flow rate of the liquid also needs to be controlled carefully; if it is too fast, it can lead to overpressure in the pipelines or the activation of the safety valves.
For our water-bath vaporizer, a temperature of over 35 degrees is sufficient; an interlock should be activated if the temperature drops below 20 degrees. There is also an interlock in place when the temperature of the nitrogen exiting the water-bath vaporizer is low.
Excessively high temperatures, large amounts of low-temperature liquid, incomplete heat exchange, rapid vaporization of the liquid, and a high coefficient of thermal expansion – all these factors, combined with a fixed heat exchange area in the water bath vaporizer, can cause severe vibrations in the pipes. Such intense vibrations can damage the welds, and high-pressure gases pose a great danger
Doesn’t this happen when the temperature is low? Isn’t carburetor vibration caused by the condensation of water vapor?