FLOW RATE MEASURING DEVICE

• Main Authors: NARAHARA HIDEAKI, NAKAGAKI KOJI, AKIYAMA TETSUO, NAKAYASU TAKESHI
• Format: Patent
• Language: English
• Published: 12.06.1991
• Subjects: BLASTING; COMBUSTION APPARATUS; COMBUSTION PROCESSES; CONTROLLING; HEATING; LIGHTING; MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; MECHANICAL ENGINEERING; METERING BY VOLUME; PHYSICS; REGULATING; REGULATING OR CONTROLLING COMBUSTION; SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES; TESTING; WEAPONS

PURPOSE:To make the title device highly accurate in measuring a flow rate in a full flow zone while allowing the use of general-purpose pressure sensors by a method wherein said device is provided with an arithmetic and control unit which outputs the signal of a flow rate calculated by adding the product of a flow rate value obtained from a fixed throttle system and a coefficient which increases as the flow rate becomes higher, to the product of a flow rate value obtained from a variable throttle system and a coefficient which decreases as the flow rate becomes higher. CONSTITUTION:An arithmetic and control unit 8 which receives inputs signals from first and second pressure difference sensors 6, 7 and a signal from an opening degree sensor 3, calculates every moment both flow rate values through a fixed throttle system and a variable throttle system on the basis of a signal from each sensor and the relation between a prestored flow rate coefficient of a fixed throttle means 2, and a flow rate coefficient with respect to the opening degree of a variable throttle means 5, such a relation being expressed in the form of a formula or a table. Furthermore, the arithmetic and control unit 8 changes over the flow rate value obtained by the fixed throttle means 2 to the flow rate value obtained by the variable throttle means 5 according to a flow rate zone, or outputs a flow rate value signal prepared by weighted mean. In addition, the unit 8 has a control function for controlling a flow rate, or a pressure difference of an opening degree of the variable throttle means to a predetermined value and is constituted so as to regulate the opening degree of the variable throttle means 5 by sending an opening degree control signal to a variable throttle driving means 4.