Experimental installation for investigating the parameters of an NMR tracer-flowmeter

Abstract

The system for establishing and regulating the flow comprises the tank i, the pump 3, the branches 2 and 4 and the exchangeable attachments 14. The pressure-head stabilizer system comprises the aerohydraulic filters 5 and 13 and the automatic regulator 6, which maintains pressure in the filter 5 tank at a given value by means of a reference piston manometer and a bypass valve provided with a negative feedback. The flow-measuring system comprises the throwover device 15, which is controlled by the setting timer 16, the metering vessel 20, the vibration-frequency dynamometer with a digital display 17, the reference weight 18, and the detainer 19. The system operates in the following manner. When the flow attains a steady-state condition, the dynamometer is loaded with the reference weight. After the first test filling of the tank 20 according to the developed technique, the operating time of the throwover device is selected in such a manner that the mass of the tank with the liquid is equal to that of the reference weight. This makes it possible to utilize a single dynamometer working point irrespective of the flow and to calibrate the dynamometer before each weighing. The setting of the throwover device duration of operation is carried out by means of the decade switches of the metering divider type IK3-15 with an error not exceeding hundredths of a second. The metering divider operates in conjunction with a crystal frequency generator and in accordance with a set time interval it transmits pulses to the throwover device control unit. This device is driven by means of electromagnets which receive the discharge of a capacitor battery through a thyristor. Let us note that the adopted technique made it possible to reduce the duration of a single flow-measuring cycle on an average to 1 min and to ensure an error of 0.016%.