How is the shaft power of a plunger-type metering pump calculated?
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How is the shaft power of a plunger-type metering pump calculated?
Effective power of a reciprocating pump = density of the liquid being transported * g * volumetric flow rate of the reciprocating pump * head of the reciprocating pump / 1000. Shaft power of a reciprocating pump = effective power of the reciprocating pump / efficiency of the reciprocating pump
:)Not a professional in this field, so I can’t provide theoretical assistance to you； As I understand it, for a metering pump, one first needs to know the pump’s torque, and then calculate the shaft power of the pump.
How is the head of a reciprocating pump calculated?
The head of a reciprocating pump is given by the formula: h0 + (p_surface + p_true) / r + 2 – (w1)² / (2g). Where: h0 is the head difference between the inlet and outlet of the pump, in meters； p-table — Pump outlet pressure, Mpa ； p_true – reading of the vacuum gauge at the pump inlet, in Mpa ； w1——Volume flow rate at the pump inlet, m/s ； w2 —— volumetric flow rate at the pump outlet, m/s ； g——acceleration due to gravity ； r — liquid density.
The plunger pump is a type of positive displacement pump; therefore, P axis =10 to the power of 5 * (Pd – Ps) * Q / 102η, where Pd is the outlet pressure in Mpa, Ps is the inlet pressure in Mpa, and Q is the flow rate in m3/s
The power calculation for reciprocating pumps is different from that for other types of pumps. It can be said that existing books and materials do not provide detailed formulas for this, as the movement speed of the plunger follows a sine curve (which is related to the ratio of the connecting rods), and the output power PV also varies. The usual calculation method involves first determining the average power using standard techniques, and then multiplying it by a coefficient that is typically between 1.57 and 2.2 (the peak power is 3.14 times the average power); this value varies from manufacturer to manufacturer.