GB733752A - Improvements in or relating to apparatus for measuring the quantity of heat suppliedby a liquid flow - Google Patents

Abstract

733,752. Measuring quantity of heat. GAILLOUD, H. Sept. 22, 1953 [Sept. 22, 1952], No. 26163/53. Class 97 (3). Apparatus for measuring the quantity of heat supplied by a liquid flow at variable temperature, of the kind comprising a meter and a distributer operated by means responsive to the temperature of the liquid or to the difference in temperature at two points of a circuit, the distributer being adapted to direct into the meter, respectively through two closing devices controlling the flow of liquid, a part of the flow proportional to the temperature thereof, the remainder flowing through a by-pass, is characterized in that the aforesaid meter is of the type wherein the fall in pressure is proportional to the square of the speed of liquid flow therethrough, and in that the distributer is arranged in such a manner that the variable cross-sections of the closing devices (which cross-sections determine the distribution of liquid between the meter and the by-pass) are maintained so as to satisfy the following relationship automatically and independently of the speed of the liquid where A, B, C are the cross-sectional areas respectively of the closing device of the meter, the closing device of the by-pass, and a gauge of constant cross-section equivalent to the meter, #T is the temperature scale of the apparatus, #T=Tmax - Tmin, and T is the temperature of the liquid. The apparatus may be of a form responsive to a temperature difference at two points in a circuit; in this case T is the temperature difference. As shown in Figs. 1, 2, liquid enters a chamber 2 by way of a conduit 3 and passes through apertures 14, 15 in a plate 10 to cavities 4, 5. A conduit 6 leads from cavity 4 to a meter 7, and a by-pass 8 leads from cavity 5 to the outflow from the meter. Meter 7 is of the kind wherein the fall of pressure is proportional to the square of the liquid flow. A bimetallic strip 16 mounted in chamber 2 controls a plate 12 which slides across plate 10. As the temperature rises, aperture 15 is progressively covered and aperture 14 progressively uncovered, so that the liquid, at first flowing entirely through the by-pass, flows more and more, and finally entirely, through the meter. Aperture 15 is of constant width, but aperture 14 has its sides curved in such a manner that the formula stated above is satisfied. In modifications, the apertures are formed in a cylinder and covered or uncovered by a sleeve, or the apertures are both of constant width and plate 12 is moved through a lever with a cam slot therein. In a further modification, the bimetallic element is of spiral form and rotates a plate over apertures in a disc. A differential apparatus measuring the quantity of heat supplied to, e.g., a radiator, has two spiral bimetallic elements, one situated in the inflow and the other in the outflow. One element is wound on a fixed spindle but rotates the spindle on which the other is mounted, the latter element rotating a plate over apertures in a disc.