| 摘要 |
FIELD: mechanical engineering; pumps. ^ SUBSTANCE: method comes to measuring pressure differential at pump inlet and vapor in cavitation zone of pumped liquid initiated by Venturi cavitation tube with pinched section placed on bypass line. Bypassing of part of liquid in bypass line is provided by means of shutoff cocks, auxiliary pump and liquid flowmeter. Dependence of maximum flow rate of liquid through cavitation tube from pressure at inlet is set experimentally. Preliminarily pressure of saturated vapors of liquid at handling temperature is determined and, using corresponding formulas, time of staying of liquid in metastable state in cavitation tube depending on flow rate is found. Basing on time of staying of liquid in metastable state in pump calculated by corresponding formula maximum flow rate through cavitation tube providing adequacy of metastable conditions of cavitation in pump and cavitation tube is determined, said maximum flow rate being set on cavitation tube by means of cocks. Pressure differential is found - difference in pressure at pump inlet and pressure in neck (pocket) of cavitation tube-determining sought for positive suction head of pump. ^ EFFECT: improved efficiency of method owing to taking into account conditions of no equilibrium of cavitation in pump and increased reliability of measurements of positive suction head of pump. ^ 1 dwg |
