Method and device for changing number of running pump

Abstract

Abstract PURPOSE: To move the point of changing number of pumps for each resistance curve securely by the pressure difference between pump suction pressure for a set pressure value and pump discharge pressure or the value of pump discharge pressure. CONSTITUTION: Water is supplied from a distributing reservoir 1 to pumps 2 connected in parallel and then conveyed via piping 3 to users 4, 5 of genrally different resistance curves. On the discharge side of the pumps 2, a pressure detector 6 and a flow quantity detector 7 are provided, signals p from this pressure detector 6 are compared with the signals P of a pressure setter 8 by a comparator 6' and supplied to a number changing control device 9. On the other hand, signals q from the flow quantity detector 7 are compared with signals Q from a flow quantity setter 10 by a comparator 7' and supplied to the number changing control device 9. For example, when the signal p is lower than a set pressure P 1 , the second pump starts and stops at a pump change-over point C 1 , but a flow quantity q is compared with a set flow quantity Q and the second pump starts when the flow quantity is at Q 4 and stops at Q 3 . COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Masakatsu Ooya
• 👤 Tsuyoshi Tomita
• 👤 Koichi Naoi

Bibliographic Details