The self-priming pump discharges air slowly each time it operates; how can this be improved? How to operate it if using a vacuum pump to draw water?
Thread Content
This post was last edited by lee2033 on 2019-12-23 at 18:19. A 50-inch diameter self-priming sewage pump is used for mobile water pumping; the inlet pipeline consists of about 5 meters of vertical pipe and around 20 meters of horizontal pipe. Each time the self-priming pump is started, it takes more than twenty minutes to remove all the air from the inlet pipe. Due to practical constraints, the water inlet pipeline has to be this long. What methods can be used to improve it? The simplest method is to install a foot valve at the bottom of the water inlet pipe to retain water, but since the pump is used mobilely, it is not possible to keep the water inlet pipe filled with water. Moreover, the conditions at the site are not suitable for using submersible pumps, as it is not an open water surface; instead, water is drawn in from the sewage outlet. Currently, we are considering using a vacuum pump to evacuate air and draw in water. Is it necessary for the vacuum pump to be used in conjunction with a gas-water separation tank? I have seen before pump houses for irrigation and drainage using water-ring vacuum pumps to draw water into centrifugal pumps; it seems that no gas-water separation tank was used, with the vacuum pump being used directly for exhaust. Once the water had been pumped out, the vacuum pump was turned off and the centrifugal pump was started. But after looking up the operating procedures for water ring vacuum pumps online, it says that such pumps cannot be used for pumping water and that a gas-water separation tank is required Also, is the vacuum water intake tank the same as a siphon tank? Will using it to help absorb water and release air make it faster? Could someone provide their structural diagrams so I can study the principles behind them? Thank you!
Search for it by yourself; there are many discussions on this topic in the forums that you can refer to. Also, can’t the inlet pipeline of this pump be made shorter? Centrifugal pumps are good at discharging but not at sucking in
Should we try to divide the flow into two paths behind the self-priming pump? One path should be connected to a diaphragm pump along with the valves at both ends, and the other path should also have a valve. First, fill it with water via Route 1, then switch to Route 2 to connect
May I ask, what is the speed of a diaphragm pump when used for exhaust? Since there is no gas supply on site, pneumatic diaphragm pumps cannot be used; only electric diaphragm pumps are an option. The manufacturers of diaphragm pumps say that electric diaphragm pumps operate more slowly than pneumatic ones, so they may not be as effective for exhaust purposes as self-priming pumps
It’s okay if the electric motor runs a bit slowly; just start both of them at the same time. It’s still better than adding a vacuum pump.
The siphon tank is as shown in the figure; the material to be used is selected based on the operating conditions, while the size of the siphon tank is determined by factors such as the pump diameter and the suction height.
The diaphragm pump manufacturers say that the suction height of electric diaphragm pumps is shorter than that of pneumatic ones; considering that the inlet pipe is relatively long, it’s possible that the exhaust performance of electric diaphragm pumps is even worse than that of self-priming sewage pumps Do you mean that the outlet pipe of the self-priming pump splits into two branches, with one of those branches connecting to the diaphragm pump?