US1472931A - Feed-water-control system - Google Patents

Description

Nov. s, 1923. 1,472,931

D. B. MORISON FEED WATER CONTROL SYSTEM Filed Nov. 27. 1922 2 Sheets-Sheet 1 A l/vvE/iiroz- DONALD E). MOQ ISON YMQm/Qwmw D. B. MORISON FEED WATER CONTROL SYSTEM 7 Nov. 6 1923.

Filed Nov. 27 2 Sheets-Sheet 2 Patented Nov. 6, 1923.

some]; Beans Moaison,

or HAnTLnn'ooL, ENGLAND.

FEED-WATER-CONTROL SYSTEM.

Application filed November 27, 1922.. Serial No. 603,602.

To alien/1.0m 2'2. may concern:

Be it known that I, DONALD BARNS Mom- SON, of Hartlepool, in the county of Dun ham, England, have invented certain new and useful Improvements in Feedater- Control Systems, of which the following is a specification.

This invention relates to feed water control systems of the kind in which a tank or vessel contains a float which controls the supply of supplementary water into the system.

The invention consists broadly in the provision in association with a main condenser, and a pump for withdrawing condensate from the main condenser and discharging it directly to the suction of the boiler teed pump, of a head tank having a pipe connected up to the suction side of the feed pump and means controlled by a float within the head tank for controllingthe operations of the feed pump. The float Within he head tank may also be utilized for automatically controlling a bye pass back to the main condenser or other suitable situation.

The invention further consists in the utilization of the float in the elevated tank for operating a valve to effect hydraulic i control of a further valve or valves for regulating the flow of water into or from the system.

The invention also comprises apparatus whereby the control of the supply of waterinto the feed system is operated hydraulically under the control of the float. A throttle valve arranged on the discharge side of the feed pump may be operated in similar manner and my invention also contemplates a system wherein a valve admitting water to the feed system and a' valve throttling the discharge from the systemare'bothhydraulically controlled from the same float operated valve. In feed water systems it is often desired to maintain a certain pres sure orhead of water on the suction side of the feed pump, and for this purpose the tank or vessel referred to is arranged at such a height as will produce the desired pressure on the suction side of the pump. It is also usual to provide a valve for admitting water from the feed or reserve tank into the condenser or condensate pump suction so that a supplementary supply of water may be admitted when required. In ac pressure on the suction side of the feed pump rises.

cordance with the present invention the float is arranged to hydraulically control this valve in such a manner that when the float is in its normal'positio'n the valve ad mitting water into the system is closed, while when the float'falls below its normal position the valve admitting water into the system is opened and the supplementary water admitted immed'iatjely restores the by raising the level of the water in the tank. -When desired, the float may operate in a similar manner a throttle valve placed on the discharge side of the feed pump, so that thevalve is closed by the falling float when the level of water in the tank is lowered, and opened when the water level Thus, should the demands of the boiler be such that the waterre'quired is in excess" of the condensate discharged from the condenser, and the float in'the tank falls, the valve on the discharge side of the feed. pump is throttled until the supplementary water enters the system and restores the pressure on the suction side of the feed pump, thus any serious reduction of pressure in the system is avoided and a supply of water suflicient tor the boilers is always available.

Fig. 1 illustrates diagrammatically oneconvenient form of my invention showing the method ofcontrolling-the supply of water into the system, and Fig. 2 shows diagrammatically a modified 'fo'rm of'Fig. 1, in which the float also controls the thr'ot" tle val r-e arranged on the discharge side of V the feed pump.

In Fig. '1, (bis the condenser from'which the condensate is removed by the extraction pump Z) which discharges directly, or other- I wise, into the suction of the boiler feed. pump 0 which discharges to the boilers through the pipe 91.. (Z is a tank which is arranged at such a height as will give thedesired pressure at the suction of the feed pump c,'and e is the valve which controls the admission of water into the system. In the illustration, the valve 6 is shown admitting water into the suction of the cons densate pump, but the admission may be ar- 105 ranged elsewhere if desired. For example, the valve 6 may be connected to the main condenser. As will be seen from the drawing the valve e which is shown as of the piston type, is lifted by a spring, but is normally held closed by the pressure of water from the elevated tank with which it is in communication by way of valve is and pipe 7. g is a leak-cit pipe through which the escape of water is controlled by the valve h. When the plant is working under normal conditions the level of the water in the elevated tank (Z remains practically constant, any excess passing through the over-flow pipe j into the feed tank or elsewhere. When however, the load on the main engine is reduced and the condensate discharged by the extraction pump 6 is insuflicient for the requirements of the plant, the level of the water in the tank (Z falls, the float closes the valve when the upper side of the piston in the valve 6 is relieved of the pressure of water and the spring opens the valve which admits water from the feed or reserve tank Z into the system. As soon as the load on the main engine increases and the water is more than suflicient for the requirements of the boilers, the level rises in the tank (Z, the valve 70 is opened, and the pressure on the piston of the valve 6 is increased when the valve closes and the supply of supplementary or additional water is cut off.

In Fig. 2 the valve 6 is controlled by the float and operates in a similar manner to that described in Fig. 1. As the level of water in the tank (Z falls the pressure of water in the pipe f is lowered by reducing the quantity of water flowing through the valve 72 until the falling float closes the valve 70 and the pressure of water in the pipe f is completely relieved.

l-Vhen the pressure in the pipe f falls the valve 6 opens and admitswater from the feed or reserve tank Z into the system. At the same time the falling pressure on the top of the piston of the valve m allows the spring to close the valve in and so throttle the discharge from the feed pump 0 until sufficient water has entered the system on the suction side to restore the level of water in the tank (Z.

The valves 6 and m come into operation when the water in the tank (Z is at a predetermined level which may be the same or different for each valve, but such levels may be varied by varying the leak-ofi through the valve it.

Although I have shown by way of example certain constructions, it is to be understood that the valves 6 and m and the various parts may be constructed in any convenient manner so long as they permit of the operation herein described.

hat I claim and desire to secure by Letters Patent is 1. A feed water system comprising a condenser, a pump to which condensate from the condenser flows, an elevated tank and a connecting pipe between said elevated tank and the suction pipe of said pump.

2. A feed water system comprising a condenser, a pump to which condensate from the condenser flows, an elevated tank, a connecting pipe between said elevated tank and the suction side of said pump, a float in said tank, a valve directly operated by said float, said valve operating to effect control of the feed water system.

3. 9 feed water system comprising a condenser, a pump to which condensate from the condenser flows, an elevated tank, a connecting pipe between said elevated tank and the suction side of said pump, a float in said tank, a valve directly operated by said float, said valve operating to effect hydraulic control of a valve for regulating the flow of water to the feed system, from a source of supply. 4 A feed water system comprising a condenser, a pump to which condensate from the condenser flows, an elevated tank, a connecting pipe between said elevated tank and the suction side of said pump, a float in said tank, a valve directly operated by said float, said valve operating to effect hydraulic control of a valve for regulating the flow of water from the feed system to the boilers.

5. A feed water system comprising a. condenser, a pump towhich condensate from the condenser flows, an elevated tank, a connecting pipe between said elevated tank and, the suction side of said pump, a float in said tank, a valve directly operated by said float, said valve operating to effect hydraulic control of a valve for regulating the flow of water from the feed system to the boilers, a supply tank, a. pipe connection between said supply tank and the suction side of the feed system, a valve in said pipe for controlling the flow oi water to the feed system from said supply tank under control of said hydraulic control valve and said float operated valve.

In testimony whereof, I aflix my signature.

DONALD BARNS Monrsou.

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