Improvements in Regulators for Percussion Turbines or Impulse Wheels.
Year: 1893

page_text: Date of Application, 22nd Feb., 1893—Accepted, 22nd Apr., 1893
COMPLETE SPECIFICATION.
Improvements in Regulators for Percussion Turbines or Impulse
Wheels.
CHARLES LOUIS HETT of Turbine Foundry Brigg in the County of
Lincolnshire Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
-
This invention has for its object the regulation of percussion turbines or impulse
wheels by means of a water pressure or hydraulic cylinder, containing a combined
piston and valve, called shortly a piston valve.
A portion of the motive water is admitted to the hydraulic cylinder by a small
valve, which may be controlled by an ordinary centrifugal governor of good
construction or it may be worked by hand. This invention has some features in
common with that of my Patent No. 21,149 A.D. 1891. This invention is more
particularly applicable to wheels driven by two or more jets, such jets may be at a
distance apart from one another or they may be in such close proximity that the
water will combine after leaving the ports. The hydraulic cylinder may be either
vertical, horizontal or inclined.
I am aware that the motive water has been made use of for regulating the
admission of water to hydraulic motors I therefore make no claim for its
application except in conjunction with a piston valve and an impulse wheel in the
manner described in this Specification and in the accompanying drawing.
Fig. 1 shows my invention as applied to jets placed at a distance from one
another.
Fig. 2 shows its application when the jets are in close proximity to one another.
The jets may be either circular or rectangular in section.
Fig. 3 shows a cross section through the hydraulic cylinder and the small valve
cylinder.
The same reference letters apply to all the figures on the drawing.
A. A. is the percussion turbine or impulse wheel fitted with suitable
buckets, B. B. are the jets or ports, C is the piston valve which covers the whole
or any number of the ports as may be required, D is the hydraulic cylinder, E is
the small valve cylinder, and. F is the small valve, which is operated either by a
governor or by hand. On the drawing the arrangement by which the valve is
operated either by the governor or by hand is shown. If a governor is
not required, the small valve F is operated by an ordinary hand wheel and
screw or some similar arrangement, G is a screw which regulates the admission
of the water to the small valve, and also acts as a strainer to exclude any
floating matter which might interfere with the action of the valve, H is the
inlet port J. J. are the ports from which the water is led by the pipes K. K. to the
two ends of the hydraulic cylinder, L is the waste or exhaust pipe, M is a small
hand wheel working the valve F by means of a screw.
The action is as follows, before starting the percussion turbine or impulse wheel,
the small valve F is lowered by turning the hand wheel M, water is admitted into
the top of the hydraulic cylinder through the lower port J and pipe K, the piston
valve C descends and opens the jets, the opening continues until the governor rises
and thereby raises the small valve F and thus stops the flow of water into the top
of the hydraulic cylinder. If there is no governor the small valve F is raised by
the hand gear when the required speed is attained. If the speed of the impulse
wheel drops through an increase in the load, the governor lowers the valve F and
admits more water into the top of the hydraulic cylinder. On the other hand
when the speed of the percussion turbine or impulse wheel exceeds the normal

page_text: speed the governor raises the small valve F and admits the motive water into the
lower end of the hydraulic cylinder and below the piston valve C and thus closes
the ports or jets by means of the piston valve, the muff of the governor returns to
its normal or middle position. Each movement of the small valve F which admits
the motive water to either end of the hydraulic cylinder places the opposite end of
this cylinder in communication with the exhaust or waste port and pipe.
When no governor is employed the small valve F is operated by the hand wheel
or its equivalent, and water is admitted to operate the piston valve and the small
valve is closed again as soon as the piston valve has travelled a sufficient
distance to regulate the supply of water through the jets to the impulse wheel.
The screw G is set as wide open as the work will allow. The wider it is opened
the more sensitive is the action of the governor, but if too wide "hunting" is
inevitable. When once set, it is not altered unless the conditions of the work
requires it to be readjusted.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is,
The combination of a percussion turbine or impulse wheel with a water pressure
or hydraulic cylinder and a piston valve supplied by means of a smaller valve,
which smaller valve is adjusted as required either by hand or by a centrifugal
governor substantially in the manner shown on the drawing.
Dated this 21st day of February 1893.
CHAS. LOUIS HETT.