Patent GB-677259-A (GB)
Title: Improved arrangement for the volumetric measurement of fluids
Inventor: INGHELBRECHT MICHEL
IPC: G01F5/00
Filed: 1949-10-18
Abstract: 677,259. Gas meters; liquid meters. COMPAGNIE GENERALE DE GAZ ET D'ELECTRICITE. Oct. 18, 1949 [Oct. 19, 1948], No. 26774/49. Classes 54 and 69 (i). Apparatus for the volumetric measurement of fluids comprises a main conduit and a bye-pass in which a measuring instrument is situated, the main conduit being provided with a main constriction controlled by the pressure downstream of the measuring instrument and the pressure downstream of the constriction so as to keep said pressures equal, the main and byepass conduits each having a variable auxiliary constriction downstream of the main constriction and measuring instrument respectively, both auxiliary constrictions having passages the cross-sectional area of which may be varied in constant proportion, the latter constrictions being controlled in dependency of the pressure drop caused by at least one of them. A gas flow pipe 1, Fig. 2, is divided into an auxiliary branch 3 having a meter and a main flow pipe 2. The main flow pipe 2 has a constriction 5, the controls for which are connected with the auxiliary branch 3 downstream of the meter by a duct 7 and a point upstream of the constriction by a duct 7<SP>1</SP>. Constrictions 8, 10, the controls for which are connected by a duct 13 to a point in the main flow pipe 2 and by a duct 14 to a point near the junction of the main flow pipe 2 and auxiliary branch 3, are arranged in the main flow pipe 2 and the auxiliary branch 3 at points upstream of this junction. Another variable constriction 31, the controls for which are connected with the atmosphere and the junction of the main pipe 2 and auxiliary branch 3 may be provided on the upstream side of the meter. The invention may be applied to a town's gas meter (Fig. 3) in which gas passes from a delivery duct 1 to a space 20 which leads to an auxiliary duct 3 and a main duct 2. A valve 21 between the space 20 and the main duct 2 is controlled by a spring 28, a diaphragm 22, one side of which is connected with the main duct 2 by a channel 25 and a second diaphragm 23, one side of which is connected with the downstream side of a measuring device 134 by a channel 27. Gas passing into the auxiliary duct 3 then passes through a pressure regulator 30 provided with a valve 31 regulated by a diaphragm 34 the position of which is determined by the gas pressure in the utilisation duct 9 and atmospheric pressure. Gas leaving the pressure regulator 30 by a duct 33 is measured by an instrument 134, which includes a slide valve 41 actuated by a diaphragm 42 which separates two measuring chambers 43, 44. Gas entering the first chamber 43 causes gas in the second chamber 44 to be discharged through ducts 45, 47 and also causes the slide valve 41 to move so that gas can enter the second chamber 44 and cause gas to be discharged from the first measuring chamber 43 through ducts 46, 47. Gas in the main duct 2 is joined by gas from the measuring device 134 in a device 50 comprising a constriction 51 for the main gas current and a constriction 52 for the auxiliary gas current. The two constrictions 51, 52 are controlled by conical elements 54, 55 respectively, connected together and controlled by a diaphragm 56 one side of which is at the pressure of gas in the main duct 2, the other side being at the pressure in the utilisation duct 9.