Naismith pump (chlorine compressor)

I have also been considering this frequency conversion in order to save energy on Nash pumps; I hope you can look into it

Found this post; let’s take a look together

The Naga pump is a positive-displacement pump; it has no characteristics of a centrifugal pump, nor does it possess such features! The relationship between the speed of a centrifugal pump and its flow rate, head, and power is respectively proportional, quadratic, and cubic! Therefore, using an inverter with centrifugal pumps saves energy and allows for controllable flow rate! Nash pumps are not acceptable!

The water ring vacuum pump belongs to the category of vane-type machines; energy conversion is achieved through the rotation of the impeller, and the power consumed is primarily used to give the water ring the kinetic energy of the compressed gas. During the suction phase, the impeller converts the mechanical energy obtained from the drive mechanism into kinetic energy of the water ring that rotates against the inner wall of the pump, thereby creating a suction cavity to draw in gas. The energy conversion during this phase is similar to that in centrifugal pumps, with the shaft power being proportional to the cube of the rotational speed. During the exhaust phase, the kinetic energy acquired by the water ring is converted into kinetic energy that drives the impeller to rotate, as well as pressure energy used to compress the gas; the working principle during this phase is similar to that of a hydro turbine. Taking everything into account, it is believed that for a pump of a certain specification, the shaft power is approximately in a quadratic relationship with the rotational speed. 　　German industrial standards: DIN 28431 \"Acceptance Rules for Liquid Ring Vacuum Pumps in Vacuum Technology\" and China’s national standard GB/T 13929 \"Test Methods for Water Ring Vacuum Pumps and Water Ring Compressors\" both stipulate that when testing and accepting pumps, if the actual rotational speed deviates from the designed speed by no more than 3%, the impact coefficient of this speed variation on shaft power can be calculated using a quadratic relationship. 　　Since the volume of air is proportional to the square of the rotational speed, it is not advisable to increase the intake volume by raising the rotational speed. For example, in the 2BE series of pumps, which are most commonly used in various industries in our country and have a capacity of 40 m3/min (with a maximum pressure of 33 mbar), at an operating speed of 740 r/min – the usual speed – the gas flow rate at an inlet pressure of 400 hPa is 39.6 m3/min, while the shaft power is 53 kW ； When the rotational speed increased to 820 r/min, it rose by 10.8%; the gas volume was 43.7 m3/min, an increase of 10.4%, showing a linear increase. Meanwhile, the shaft power was 64 kW, an increase of 21%, indicating an approximately quadratic increase.

Can frequency conversion actually be used? Can’t understand it