Patent GB-194370-A (GB)
Title: Improvements in means for measuring and delivering gas at a known rate
IPC: G07F15/00
Filed: 1921-12-06
Abstract: 194,370. Trade, Secretary of the Board of, and Boys, C. V. Dec. 6, 1921. Addition to 180,080. Gas meters.-Relates to modified apparatus, for use in connection with the recording gas calorimeter described in the parent Specification, for maintaining constant the volume of gas, if measured at standard temperature and pressure and saturated with water vapour, passed in unit time by a gas measuring and delivering device operating at substantially atmospheric pressure, notwithstanding possible deviation of the gas measured from predetermined conditions of barometric pressure and temperature. The gas is passed through a saturator S, containing porous material which is kept wetted with water, before entering the measuring element X, Figs. 1 and 4, which consists of a constant volume meter drum loosely mounted on a spindle Z which is driven from a water-wheel A controlled by a clock escapement through epicyclic gearing 0, R, S, T and reduction gearing V, W. The epicyclic gearing comprises a pinion R, Figs. 1 and 6, gearing with a sun wheel 0 and a ring of teeth S carried by a spur wheel D on a sleeve which is driven by the water wheel A. The sun wheel 0 is controlled by an integrator K which is held stationary or receives motion in one direction or another according as the gas is at standard temperature and pressure or varies therefrom. The motion of the integrator is transmitted to the sun wheel through gear wheels Q, P, the latter of which is mounted fast on a sleeve which also carries the sun wheel O. The integrator receives motion in one direction or another or is held stationary according to the position of a ball M resting between the integrator and an inclined disc F which is rotated by a wheel E gearing with the wheel D which is driven from the water wheel A. The ball is held at the centre of the inclined disc or is moved to one side or the other of the centre by a pivoted forked arm N which is operated by the rise and fall of an air bell N<5> consequent upon changes in atmospheric temperature and pressure, the air in the bell being saturated with water vapour. The forked arm N is preferably provided with a pointer N<2> which moves over a scale N<3> graduated to show variations of volume due to variations of temperature and pressure from standard. The pinion R is carried upon an arm T mounted on a shaft U which drives, through reducing gearing V, W the spindle Z upon which is loosely mounted the measuring drum. The epicyclic gearing is asymmetrical and gives a greater reduction to the motion received from the integrator than it gives to the motion received from the water-wheel, thereby increasing the mechanical advantage of the integrator and enabling the meter spindle to be satisiactorily controlled by the frictional drive of the ball M. The meter drum has solid end discs a<5>, a<6> instead of the usual aprons, and a plurality of radial partitions forming the measuring chambers and extending between the outer wall of the drum, in which are formed the inlet and outlet apertures for the chambers, and a central closed chamber a<7>, Fig. 4, which serves to render definite the capacity of the chambers and to impart buoyancy to the drum. For enabling the water level in the glass bell within which the drum works to be accurately ascertained and set, a clip b<5> mounted on the sleeve in which works the spindle Z carries a series of adjacently mounted upwardly pointed pins b<6> so supported that while some points lie beneath the surface of the water, others break through the surface. A stop a<14>, Fig. 1, is clamped to the spindle Z so as to engage with a stop a<15> attached to the drum when the latter, in consequence of any failure of supply of gas while the spindle is still kept rotating, screws itself along the spindle until it is so prevented from continuing its motion. Thereafter rotation of the drum will forcibly turn the drum and cause water to be lifted in the compartments and the resistance so offered will stop the clock. If subsequently the gas supply is continued, the drum screws itself to the other end of the spindle, as described in the parent Specification and closes the gas inlet pipe a<9>. If water has to be added to maintain the water level in the measuring chamber, the necessary water is drawn from the saturator S so that it may already be saturated with any soluble constituents of the gas.