GB1216206A - Improvements relating to heat meters - Google Patents

Abstract

1,216,206. Heat meters. FERRANTI Ltd. Aug.20, 1969 [Aug. 24, 1968], No.40569/68. Heading G1D. An integrating meter for measuring the quantity of heat exchanged between a fluid passing through a heating system and its surroundings comprises two temperature sensors for sensing the temperatures of the fluid on entering the system and that on leaving to position a table 29, which is movable in a direction normal to the plane of Fig.3, in accordance with the difference between these two temperatures, the table 29 carrying a constant speed motor 30 driving a pinion 31 and thus a gear wheel 32, an edge of a rotatable disc 34 being in contact with the flat face of the gear wheel 32, so that the speed of rotation of the disc 34 is dependent on the radial positions of its edge with respect to the gear wheel 32 and thus on the measured temperature difference, a pear-shaped streamline body 14 mounted for axial movement over a restricted range in a pipe 11 which carries the fluid, the body being mounted on a rod 15 connected to a lever 18 pivoted on a knife edge 19 and coupled to spring 23 whereby the body 14 is urged towards the upstream end of its range of axial movement but will assume a position in its range of movement corresponding to the mass flow of fluid along the pipe 11, the lever 18 also being connected by a pivoted lever 21 to a carriage 38 carrying a pair of freely rotatable wheels 39 (only one shown) mounted on parallel axes with each other, are wheel 39 being also in contact with the face of the disc 34 and the other wheel 39 with the face of a further disc 36, the radial position of the contacting point of the wheel 39 with respect to the disc 36 being dependent on the mass flow of fluid and the disc 36, which is coupled to a register being driven from the disc 34 through the wheels 39, so that the net speed of rotation of the disc 36 will be proportional to the integral with respect to time of the product of mass flow of fluid through the heating system and the temperature difference between the fluid on entering and leaving the system. The pipe 11 forms the supply pipe for heating fluid to the system. The temperature sensors are preferably in the form of liquid filled jackets as 49 surrounding the fluid supply and return pipes, the liquid being thermally expansible and the jackets being each connected by tubing. to a cylinder and piston actuator. The two cylinder and piston actuators are arranged to act in opposition to each other to control the position of the movable table 29 whereby it will be positioned in response to the difference in the two temperatures sensed by the sensors. The rod 15 is slidable in a boss 16 in the pipe 11 and an adjusting screw is provided for the tension in the spring 23 whereby the sensitivity of the mass flow rate sensor can be adjusted. The disc 36 is arranged to drive a register type of indicator through a gear-box (not shown).