water ring vacuum pump technical parameters
What are the technical parameters of water ring vacuum pump commonly used in the market? The following are the technical parameters of water ring vacuum pump:
1、 Flow: the volume of liquid discharged by the pump in unit time, expressed by Q. Unit: L / S = 3.6m3/h
2、 Head: unit weight of liquid through the pump energy is called head. The head of the pump, including the suction head, is approximately the pressure difference between the outlet and the inlet of the pump. The head is expressed by H, and the unit is meter (m). The pressure of the pump is expressed in MPa (MPA), H = P / ρ. 1MPa = 10kg / cm2
3、 Pump efficiency: refers to the effective power of the pump and shaft power ratio. η = PE / p the power of the pump usually refers to the input power, that is, the power transmitted by the prime mover to the pump shaft, so it is also called shaft power, expressed by P. Effective power is the product of pump head, mass flow and acceleration of gravity. E = ρ GQH (W) or PE = γ QH / 1000 (kw) ρ: density of liquid transported by pump (kg / m3) γ: gravity of liquid transported by pump γ = ρ g (n / m3) g: acceleration of gravity (M / s) mass flow QM = ρ Q (t / h or kg / s).
4、 What is NPSH? What is suction distance? When the pump is working, the liquid at the inlet of the impeller will produce vapor due to a certain vacuum pressure. Under the impact of liquid particles, the vaporized bubbles will erode the metal surface of the impeller, thus damaging the metal surface of the impeller. At this time, the vacuum pressure is called vaporization pressure, and the NPSH refers to the excess energy of the unit weight of liquid at the suction of the pump that exceeds the vaporization pressure. The unit is marked with meter and (NPSH) r. Suction head is the necessary NPSH Δ H: that is, the vacuum degree that the pump is allowed to absorb liquid, that is, the allowable installation height of the pump, in meters. Suction head = standard atmospheric pressure (10.33 m) - NPSH - safety value (0.5 m) standard atmospheric pressure energy pressure pipeline vacuum height 10.33 M.
5、 The characteristic curve of the pump is usually called the performance curve or characteristic curve of the centrifugal pump, which indicates the relationship between the main performance parameters. In essence, the performance curve of the centrifugal pump is the external manifestation of the movement law of the liquid in the pump, which is obtained through the actual measurement. The characteristic curve includes: flow head curve (Q-H), flow efficiency curve (Q - η), flow power curve (q-n), flow NPSH curve (Q - (NPSH) r). The function of the performance curve is any flow point of the pump, and a group of relative head, power, efficiency and NPSH values can be found on the curve. This group of parameters is called working state, which is called work state for short The working condition of the highest efficiency point of centrifugal pump is called the best working condition point, which is generally the design working condition point. Generally, the rated parameters of centrifugal pump, that is, the design operating point coincides with or is very close to the optimal operating point. It is very important to know the performance parameters of the pump because it can not only save energy but also ensure the normal operation of the pump.
6、 The performance of the pump is measured, the flow is measured by precision worm flowmeter, and the head is measured by precision pressure gauge. The suction head was measured with a precision vacuum gauge. vacuum pump reminds you that the power must be measured by precision shaft power machine. The rotational speed was measured with a tachometer.