Venting issues of centrifugal dump pumps
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Conventional centrifugal unloading pumps usually require air release and priming before starting. The standard procedure is to open the bypass vent valve installed between the pump outlet and the check valve; once the material reaches the vent valve due to gravity, the valve is closed, and then the pump is started (some steps are omitted). Question: Some material is discharged with each exhaust process, and the manufacturer does not take this material away, nor can we handle it ourselves. I would like to ask if anyone has any good piping methods that allow the pump to be started without the need for intentional venting? Or should a self-priming pump be chosen?
You use centrifugal pumps for unloading – what kind of material are you unloading? We are working on a project that involves using centrifugal pumps to unload trucks. We learned earlier that these pumps are not effective at ensuring complete unloading; is there a better pump suitable for this task?
This post was last edited by yangyong1980 on 2016-3-9 at 11:47. For a centrifugal pump, the simplest, safest, and most environmentally friendly approach is to open the outlet valve or the return valve; by utilizing the principle of a U-tube, waiting for about a minute will suffice, after which the outlet valve can be closed. Start: lol
Our company experiences such problems with salt and acid unloading pumps as well; since they are located near the neutralization tank, a small amount of material ends up in the tank. . If you want to save money, you can pour the discharged material back into the tank truck. . . . . It seems these losses are unavoidable for now
As the original poster said, a self-priming pump would work as well. A self-priming pump only needs to be filled with liquid the first time it is used; no further filling is required afterward, as the pump chamber will already contain the fluid. It can be used right away on the second use.
A self-priming pump indeed only needs to be filled once, which is advantageous in terms of material savings. From another perspective, its stability and safety seem to be lower than those of centrifugal pumps. All the unloading pumps in our factory are centrifugal pumps; given the special properties of the materials handled, such as methanol, acetic acid, hydrochloric acid, sulfuric acid, etc., the performance of these pumps is satisfactory. Suction pumps are generally used for water, and they tend to experience many problems, such as cavitation, excessive vibration, and seal leakage. It seems that repairing centrifugal pumps is relatively easy!
I understand what you mean, and I’m also thinking about whether this approach is appropriate. What I’m thinking now is to add a vent pipe with a diameter of 15 to the tank; when venting, open all the valves fully, and then start the pump after closing the vent valve. What I don’t understand is: 1. Can a self-priming pump solve this problem? (The distance from the tank truck to the pump is about 25 meters, with a U-turn in between that crosses the road). 2. What are the disadvantages of self-priming pumps compared to these ordinary horizontal centrifugal pumps?