Problems with the plate heat exchanger in water ring vacuum pumps

Water ring vacuum pumps typically use plate heat exchangers, mainly due to their high efficiency, small size, and ease of cleaning and maintenance. Plate heat exchangers are favored because they effectively increase the heat exchange area through closely arranged metal plates, thereby improving heat exchange efficiency. The calculation of the heat exchange area involves many factors, including but not limited to the fluid’s temperature, flow rate, physical properties, and the amount of heat exchange required. Generally, a preliminary estimate can be made using the following formula: \ where \( Q \) is the heat exchange rate (in watts or kilowatts), \( U \) is the overall heat transfer coefficient (in W/(m·K)), \( A \) is the heat exchange area (in square meters), and \( \Delta T \) is the average temperature difference (in K). If the current heat exchange efficiency seems insufficient, consider increasing the area of the heat exchanger. However, before making such replacements or modifications, it is indeed necessary to recalculate to determine whether the new heat exchanger can meet the operational requirements and ensure that the overall performance of the system remains unaffected. Switching to other types of heat exchangers, such as shell-and-tube heat exchangers, may be feasible, but this will depend on the specific operating conditions, space constraints, and budget considerations. Each type of heat exchanger has its appropriate application scenarios as well as advantages and disadvantages; therefore, it is advisable to conduct a thorough technical and economic comparison and analysis before making a decision to replace it. If possible, it would be a wise decision to consult a professional thermal engineer or a technical consultant in the relevant field. .

The type of heat exchanger to use depends on the composition of the medium; plate heat exchangers offer high efficiency and low costs. For larger heat exchangers, it’s not necessary to conduct calculations – simply scale them up appropriately based on the motor power. Additionally, it’s important to check whether there are condensable gases in the gaseous medium; in such cases, it’s also possible to use cold water instead of cooling water

Even if not a senior expert, shouldn’t they say a few words too? Under the same conditions, it is a fact that ordinary plate exchangers achieve better heat transfer performance than ordinary tube exchangers. Additionally, because the internal channel area is smaller, plate exchangers are more prone to clogging; as a result, they require higher standards regarding water quality. Water ring pumps also have high requirements for the quality of the working fluid, which makes plate exchangers a more suitable choice. But in reality, there aren’t many cases where plate heat exchangers are specified; instead, shell-and-tube heat exchangers are frequently specified. So plate heat exchangers are not used in most cases. The calculation of the heat exchange area of heat exchangers has already been answered by a senior expert on the second floor; there’s no better answer than that. However, in most cases, the selection can be made based on experience; qualitatively speaking, as long as there are no requirements such as the outlet temperature on the hot side being too close to the inlet temperature on the cold side, using a larger plate heat exchanger will certainly lead to improvements. If specific operating conditions can be provided (such as operating vacuum level, shaft power, and the flow rates and properties of the fluids on the cold and hot sides), it should be possible to conduct a more in-depth analysis.

The plate exchanger is compact and takes up little space, but cleaning it of scale is troublesome, and chemical cleaning is not very effective.

I can do the calculations on my end; just send me the flow rate and temperature, and I’ll help select the appropriate design.

Excuse me, just a reminder: don’t forget to check for issues related to non-condensable gases and any blockages in the piping system. After that, decide whether a redesign is necessary.

Water ring pump working fluid heat exchanger: where does the non-condensable gas come from? It’s just a simple water-to-water heat exchange……

The plate heat exchanger must be scaled up, which has reduced its heat exchange efficiency. Replacing it with another type would make cleaning more difficult; it’s better to disassemble it and clean it.

Our workshop has a tank with a capacity of about 500 liters; inside this tank there are coiled tubes through which cold water is passed for cooling. The water ring vacuum pump draws water from the bottom of the tank and returns it to the upper part of the tank.

Please provide the vacuum pump model, heat exchanger area, circulating water temperature and flow rate, as well as the suction temperature; I can help with the calculations