Speed control method for pump in variable speed operation

Abstract

Abstract PURPOSE: To enable economical operation even when the discharge pressure of a pump is varied markedly by installing a flow rate detector on the upper stream side of the pump and a pressure detector on the lower stream side and comparing the difference of the both signals with the signal from the differential pressure. CONSTITUTION: A flow rate detector 10 is installed the upper stream side of a pump 1, and a pressure detector 9 is installed on the lower stream side, and in an adder 12, the signal from the pressure detector 9 is subtracted from the signal from the flow rate detector 10, and the output is compared with the signal from an adder 6 by means of a high selector 13. Therefore, in the operation where the flow rate more than at a point 16 is necessitated, the signal from the adder 12 becomes larger than the signal from the adder 6, and the signal of the adder 12 is selected in the high selector 13, and the operation along overload line 15 is formed. Thus, even if the discharge pressure varies markedly, economical operation is permitted. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Osamu Nagano
• 👤 Shigenobu Yamada
• 👤 Daisaku Hirata

Bibliographic Details