Discussion on the use of siphon tanks at the front end of pumps
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In water treatment, output pumps are installed in the neutralization tank, and siphon tanks or check valves are usually placed at the inlet end. I would like to know what the advantages of using siphon tanks are
The main goal is to improve the suction capacity. But no valves should be installed at the front end.
1. Operating a siphon tank is more convenient than using a check valve. 2. Inspecting the siphon tank is easier than inspecting the check valve, and it also avoids the troubles caused by leaks in the check valve.
Reply to 2# sysd8203: The check valve I’m referring to is one other than those devices placed in front of water pumps such as siphon tanks; it’s also the type of valve used in pumps that rely solely on bottom discharge valves
Reply to 3# zhangyingcang: In the case of a leak in the siphon tank, isn’t it difficult to detect such a problem until the mechanical seal is damaged? We currently use two types of systems: siphon and bottom discharge, but the performance of both isn’t very good, and the mechanical seals fail frequently.
The poster is referring to the vacuum water lift tank, right? It seems that for vacuum water lift tanks, it is essential to ensure airtightness; otherwise, it is very difficult to achieve an adequate flow rate. Once the inlet, exhaust valves, and the tank itself are properly sealed, it is quite reliable and convenient to use. (We have used them quite a lot) In situations where there are many solid impurities, the vacuum water intake tank has clear advantages. The bottom valve gets clogged easily, and it’s quite troublesome to clean. Leaks in vacuum water intake tanks result in negative pressure, making them difficult to detect. However, it can be determined by listening to the sound during pump startup and inspections. (Cavitation produces intermittent noises, and no-flow idling can also be easily detected by current and sound.) When manufacturing a vacuum water lift tank, its volume must be made larger (it cannot operate if its volume is smaller than that of the inlet pipe).
Reply to 6# pzhmotor, thank you.
In general, for the cold pumps in low-temperature methanol washing units, the flushing scheme for the mechanical seals in practical applications uses PLAN 11+52+62, which refers to a series arrangement of double-end face mechanical seals. Fifty-two of them require buffer tanks, which provide a buffer fluid for sealing the atmosphere side (usually methanol at room temperature). There is a valve above the buffer tank, which should be kept open to ensure that the pressure of the buffer fluid is lower than that of the medium. There is a sight glass on the buffer tank, and manufacturers usually mark a line near this sight glass; this line represents the normal liquid level required for the mechanical seal to operate properly. If the liquid level is above this normal level, it indicates that the mechanical seal on the medium side is leaking, allowing the medium to enter the buffer tank. As a result, the pressure inside the buffer tank increases, and the pressure switch installed on the tank will trigger an alarm due to this rise in pressure. If the liquid level is below this normal level, it indicates that the mechanical seal on the atmospheric side is leaking, causing the buffer fluid in the buffer tank to leak into the atmosphere; in this case, the level switch installed on the buffer tank will trigger an alarm due to the drop in liquid level ； Among them, 62 require nitrogen purging to prevent freezing on the atmospheric side.