Patent GB-259619-A (GB)
Title: Improvements in or relating to the automatic regulation of steam generating installations
IPC: F23N1/02
Filed: 1926-10-12
Abstract: 259,619. Loffler, S. Oct. 12, 1926. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 13, 1926.] Pressure gauges.-In a steam-generator plant more particularly for generating steam at high pressure in which combustion is regulated in accordance with the steam pressure and steam consumption, the supply of liquid, gaseous or solid fuel or air for combustion is regulated by one of the temperatures of the plant or the quantity of air for combustion is influenced by the chemical composition of the waste gases. Conjointly with the regulation of combustion, the supply of feedwater to the boiler and the pump circulating steam through the superheater are regulated and the steam consumption is indicated. In the apparatus shown in Fig. 1, the steam pressure and steam consumption are indicated on the measuring devices D, V by the ends a, b of a floating lever 1 the movement of which, due to variation of steam pressure or steam consumption, is communicated through a system of rods and levers 2 - - 6 to a fuelregulating device at B and also through rods 7, 8 to an air-supply regulating device at L. When waste gases are utilized for regulating combustion, the quantity supplied is regulated simultaneously with the air supply. The air supply is also regulated in accordance with the amount of CO2 and CO in the waste gases by connecting the lever 7 by a rod 10 to a floating lever 3 the end m of which engages with a CO2 measuring device while the end n engages a device for measuring CO. The supply of feedwater is regulated at S through a lever 11 connected to the rod 6 which controls the fuel supply. The temperature of the superheated steam is indicated on a device U by which a rod 12 connected to the rod 2 is operated to control at P the quantity of steam pumped through the superheater. During the lighting up or starting of the steam generator, the fuel and air supply regulators are disconnected from the steam pressure and consumption controls and controlled by the temperature of the superheater by disconnecting the rod 5 at g and connecting it at g' to a rod 13 pivoted to a floating lever 14 one end v of which is controlled by the temperature at the end of the superheater while the end w is controlled by the temperature at the centre of the superheater. Apparatus for transferring the rod 5 from the point g to the point g<1> is shown in Fig. 4 and comprises a bar 36 to which the rods 4 and 13 are pivoted at g, g<1>. A sliding shoe 38 on the bar 36 is provided with pivots to which the rod 5 is connected and engaging with slots 42 in a pair of side plates 39 supported in bearings 41 and adapted to be moved longitudinally to move the shoe to either of the positions at n or g<1>. The rods 6 and 8 controlling the fuel and air supplies may be operated independently by providing them with turnbuckles i, i<1>. Figs. 1 and 2, rotatable by gearing 15, 15<1> to shorten or lengthen the rods. Fig. 3 shows apparatus by which the steam pressure and consumption are indicated on the devices D, V. Steam pressure is transmitted by a piston 17 loaded by a spring 19 to a counterweighted lever 20 pivoted to a rod 21 attached to the cylinder 16 and connected at a to the floating lever 1. The pistons 24, 25 are subjected to pressure differences in the steam pipe produced by a venturi, baffle or the like and the pressure difference actuates a system of rods and levers 26 - - 31 connected at a point b to the floating lever 1. The pistons 17, 24, 25 are rotated by gearing 33 driven by an electric motor or by means of the driving gear for the steam circulating pump, when such a pump is used, to reduce friction of the pistons. Where it is desired to transmit to a distance the regulation by the indicating devices, such as the CO2 indicator, an electric servomotor 45, Fig. 6, may be used. The indicator operates a sliding contact 43 moving over motor driving a screw 46 engaging a nut 47. The latter carries a contact engaging with a contacts 44 to produce impulses operating the contact 48 corresponding to the indication of CO2. In order to indicate the steam consumption in kilograms, the steam consumption indicated at b, Fig. 1, is corrected for temperature and pressure by connecting the point a of the pressure indicator to a point q<1> of the steam temperature indicator by a floating lever 62, the latter is connected by rods and levers 63, 64, 65 to a sliding member 66 adapted to move parallel to itself in bearings 67, 68 and actuate a eliding block mounted on a lever 69 connected to the steam consumption indicator at b. The steam consumption is indicated at b<1>. The regulation of the combustion may be effected automatically or by hand by the apparatus shown in Fig. 7. The rod 6 is adapted to engage with a toothed wheel 49 on a shaft carrying a claw coupling 50, one part of which is mounted on a spindle 51 carrying a hand wheel 54 and a toothed wheel 52 engaging with a rack bar 53 for regulating the fuel supply. The hand wheel may be pulled out to disengage the coupling when it is desired to effect the regulation by hand. Pointers 55, 56 on opposite sides of a frosted-glass pane 58 indicate the rate of fuel supply. When the control is effected by hand the pointer 55 is made visible by a lamp 57. When applying the invention to a battery of boilers, the constructional details of which may vary, suitable adjustments are made in the rods and levers of the regulating apparatus shown in Fig. 1. Electrical or hydraulic apparatus may be employed instead of mechanical means to transmit the movements of the controlling apparatus to the regulating devices.