GB701339A - Improvements in or relating to the measurement of the heat content of a flowing medium - Google Patents

Abstract

701,339. Measuring heat quantities. AKTIEBOLAGET ELEKTROLUX. Dec. 5, 1951, No. 28483/51. Class 97(3) In determining the heat content of a liquid such as hot water flowing through a conduit 10, Fig. 3, part of the liquid flowing through the conduit 10 or, as shown, through a flow path 14 in shunt therewith is tapped off through a capillary pipe 12, cooled at 33 and mixed with the liquid flowing through the conduit 10 or flow path 14, the difference between the original temperature of the liquid and that of the mixture being integrated over a time interval to indicate the heat content of the liquid passing through the conduit 10 during the time interval. In a hot water installation a union 20 containing a nozzle 13 is inserted in the supply conduit 10 and water entering the shunt path 14 passes through a filter 35 into a vessel 23 which is provided with a thermometer pocket 27 in a cover 25. A throttle plate 11 inserted in a nipple 31 of vessel 23 lies between the vessel 23 and a similar one 24, the latter having a cover 26 containing a thermometer pocket 28 and having a screw shaped mixer 30. The capillary pipe 12 connecting vessels 23, 24, has a portion cast in a metal body 33 contacting a cold water conduit 34. The flow through the flow path 14 is a fixed fraction of that through conduit 10 and is proportional to the square root of the pressure drop across plate 11 whilst the flow through pipe 12 is proportional thereto. An insulation casing 36 is provided which may enclose the conduit 34. In a modification the plate 11 is replaced by a nozzle consisting of a shorter or longer pipe so as to provide the resistance thereof with components proportional to the flow and to the square of the flow. Also the extra pressure losses which occur with high pressure drops may be balanced by rounding off the internal edges at each end of pipe 12. In measuring the properties of the different flow paths a cock 51, Fig. 4, is provided on the end of conduit 10, the cock when open having a small flow resistance compared with the pressure at 56. The point 50 of a threaded valve needle 46 may be screwed into the aperture of the throttle plate 11 and a plate 49 carried by a valve stem 45 may be screwed into the aperture in plate 13, covers 48, 47 being provided to prevent unauthorized adjustment. A manometer 52 may be connected to the conduit 10 on each side of throttle plate 13 by means of pipes 53, 54.