Patent GB-190428449-A (GB)
Title: Governing Mechanism for Turbines.
Inventor: WILKINSON JAMES
Filed: 1904-12-27
Granted: 1905-02-09
Abstract: 28,449. Wilkinson, J. Feb. 23, [date applied for under Patents Act, A.D. 1901]. Steam &c. turbines.- Means are described for governing a stage steam turbine by opening or closing the valves controlling the supply nozzles and at the same time opening or closing the corresponding stage valves. The fluid impact governor described in Specification No. 24,275, A.D. 1904, is used. A two-stage turbine is shown in Fig. 1 in which the supply head 1, the stage diaphragm 2, and the exhaust head 3 are held together by a ring 4 which forms a superheating -jacket and is secured by a locking- ring 8 made in segments. Steam is supplied to a passage 12, whence it is delivered to the valve chambers 14, which are bored in the supply head and are closed at their lower ends by blocks 15 provided with valve seats and with curved ways 17 directing the steam into the nozzles 18, Fig. 2. Each nozzle has a valve 19 made integral with a piston 21 and a projection 24, through all of which passes a central channel 23. A small groove 51 is cut in the piston to allow of communication between the upper and lower ends of the cylinder. The upper end of the channel 23 is controlled by a valve 50 working in a chamber 27 which is in communication with a conduit 31 formed by a grooved strip 30, Fig. 6. The superposed strips 30 are secured in a channel in the supply head by a flange 34 formed on the locking- ring 8. At one end, the strips are turned upwards and their channels open into a chamber 44 in which is a swinging D-shaped nozzle 43 supplied with steam and controlled by the governor. When the nozzle is in the position shown, the jet is discharged through the channel 49 into the first stage, and a vacuum is formed in the chamber 44 and the conduits 31. The valves 50 are thus raised, and the upper end of each cylinder 14 is put in communication through the channel 23 with the nozzle 18 so that the pressure in it is reduced and the piston and valve 19 are raised. The ejector action of the steam jet on the tubular projection 24 further reduces the pressure above the piston and withdraws any steam flowing through the groove 51. When the piston is raised, a groove 22, which communicates through a channel 26 with the passage 23, is brought over a conduit 52 which leads to the upper end of a cylinder 57 containing the controlling-piston of the corresponding stage valve 69. The upper end of the cylinder is thus exhausted, and jacket steam, supplied by the channel 64, raises the piston and opens the stage valve. When a supply valve is closed, steam from the cylinder 14 flows to the cylinder 57 and closes the corresponding stage valve. Should the load on the turbine decrease, the governor swings the nozzle 43 over one or more of the conduits 31 so that the pressure in them is increased and the corresponding valves 50 forced downwards. The passages 23 are thus closed and the pressure above the pistons increases sufficiently to close the valves 19. Into the segment of the flange 34, adjacent to the ends of the conduits 31, is let a removable block 45, Fig. 3. By the removal of this block, the segment of the flange and ring 8 can be moved radially inwards to clear the recess in the jacket so that it can be withdrawn and the other segments then removed to allow the jacket to be moved endways for inspection of the parts.