US2103225A - Boiler feed apparatus - Google Patents

Description

Dec. '21, 1237.

V. E. M COY ET AL BOILER FEED APPARATUS 2 Sheets-Sheet l I Filed June 6, 1935 fmjezzfanz UeFZ/EMC C0 J, wider-@072,

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1937. v. E. M COY ET AL BOILER FEED APPARATUS Filed June 6, 1935 2 Sheets-Sheet 2 [XerLE'Mc @y, I

WM MMMQLM Qpy Patented Dec. 21, 1937 UNITED STATES PATENT OFFICE.

BOILER FEED APPARATUS Verl E. McCoy, Chicago, 111., and Ralph W. Anderson, Wauwatosa, Wis.;l said McCoy assignor to Wilson Engineering Corporation, Chicago, III... a corporation of Delaware Application June 6, 1935, Serial No. 25.218

3 Claims.

This invention pertains to boiler feed apparatus for various types of boilers, including locomotive boilers.

One of the advantages and objects of the invention is the provision of means for assuring a high temperature to feed water being delivered a the water temperature to a temperature that might be uneconomical tomaintain in the supply tank. a

' Other objects and advantages of the invention will become apparent from a perusal of the specification.

The drawings show a preferred form of the invention and a modified form thereof.

Fig. 1 is a side elevation showing a locomotive with one form of the invention applied thereto;

Fig. 2 is an enlarged detail view in cross section of a mixer employed in that form of the invention;

Fig. 3 is a side elevation showing a locomotive with another form of the invention applied thereto;

Fig. 4 is a sectional view on the line 4-4 of Fig. 3;

Fig. 5 is an enlarged detail view in section of a mixer employed in the modified form of the invention;

Fig. 6 is a partial sectional view on the line 6-6 of Fig. 5; and

Fig. 7 is a side elevation showing part. of a third form of the invention.

Referring first to Figs. 1 and 2, pipe. 1 is connected with the source of feed water leading to the pump 2, the latter being driven by steam supplied through the pipe 3. The pump delivers D the feed water into the pipe 4 through a check valve 5, interposed in the line to'prevent reverse flow of the water and thence into Venturi-type mixer generally designated at 6. From the mixer, the water then passes through a boiler stop and check valve 1 into the water space in the boiler. The pump is intended to deliver water into the pipe 4 at a pressure higher than the boiler pressure, and irr any case will deliver the water into the boiler whether or not heat is added to it in the mixer.

The mixer consists of a noz zleli, a chamber 9, and a Vjenturi tube l-l. I w

A pipe i2 is connected with the steam space of the boilerv for delivering live steam preferably": at V or near the boiler pressure into the chamb er oi the mixer. A valve -l-3will ordinarily be inter posed in the pipe I2'so that thesteam may be shut ofi manually from this pipe. whenever desired, or a remotely eontrolled valvemay be em- I ployed if desired. Also, if desired, a check valve 14' may be positioned in the pipe l2 to'prevent the feed water from flowing into the steam space, but permitting steam to' flow toward the mixer.

In the usual operation of the devicawhen the feed water pump starts, the water delivered by the pump will have its static pressure temporarily decreased as it passes through the chamber 9 between the nozzle and the V-enturi tube. mixer is so designed that this pressure will be lowered at least a few pounds below the pressure of the steam supplied by the pipe l2, hence this pressure difierential will entrain steam from the pipe 12 and mixing of the steam and waterv will occur in the Venturi'tube; V from the Venturi-tube its static pressure is' re stored to approximately its former pressure.

The feed water delivered by the pumpmay have a temperature ranging anywhere' f-rom atmospheric temperature up to approximately its atmospheric boiling point, depending upon the amount of heat supplied to it previously in the supply tank or elsewhere. In any event, however, the admixture of the live steam with this water will raise itstemperature greatly and will assure thedelivery of the feed water into the boiler at temperatures'which will not be-solow as to be harmful. The temperature increasethus obtained may range in practice anywherefrom 50 to 150 F. ormore, up to the-boiler tempera ture.

Not only is thetemperature of theiwa-tierraised I vision is not'i ece'ssary. The boiler-steam pres- V The I As the-water emerges sure may be maintained at all times in the pipe l2 and thelive steam may thus be held ready for use any time the feed pump starts. In this manner the automatic mixing of live steam with the feed water will be assured without requiring any complicated mechanism. Whenever the pump stops, the flow of steam through the pipe 2 also will stop, the check valve 5 serving to prevent the escape of steam back toward the pump.

In the other form of the invention shown in Figs. 3 to 6, inclusive, provision is made for using exhaust steam whenever it is available and live steam when the exhaust steam supply is lacking, for heating the water immediately prior to its entry into the boiler.

A pipe 2| is connected with a source of feed Water, for example a tender tank, or a special feed water compartment, and leads to the pump 22, the latter being driven by steam supplied through the pipe 23. This pump delivers the feed water into the pipe 24 through a check valve 25 which is interposed in the line to prevent reverse flow of the water and thence into a Venturi type mixer, generally designated as 25. From the mixer, the water then passes through a boiler stop and check valve. 21 into the water space in the boiler. The pump is intended to deliver water into the pipe 4 at a pressure higher than the boiler pressure.

The mixer consists of a chamber 28 into which a nozzle 29 projects. A needle valve 3i is employed to regulate the effective area of the nozzle and is secured to a piston 32 located in the cylinder 33. A pipe 34 is connected with the steam space in the boiler and maintains boiler pressure constantly on the adjoining side of the piston. The pipe 24 is connected with the inlet port 35 and delivers water into the chamber 33 always at a pressure higher than the boiler pressure. In

order that the pump pressure, acting through the holes 31, may not drive the piston to the left and open'the nozzle wide, a spring 38 is located as shown to partially offset the excess of water pressure. It will be of such a strength that when the pump stops and the water pressure at the port 35 ceases, the needle valve will close, but will open when the pump starts. As the velocity of the pump is increased and the water pressure thereby increases, the needle valve will recede from the nozzle outlet. Thus by regulating the effective area of the nozzle aperture the pressure of the water delivered from the nozzle into the chamber 28 may be held within close enough limits as to assure that the jet of water projected into the frustro-conical members 39 will produce a high vacuum in the chamber whereby exhaust steam at any available pressure may thus be introduced through and between the cones into the water stream. Also, this method of regulating the nozzle orifice avoids placing an undue load on the pump when it is operating at full capacity.

Preferably the members 39 are formed integrally with the Venturi tube 4!, with suitable spacing and apertures as shown, and the tube is connected with the pipe 42 for delivering water into the boiler. The exhaust steam which is drawn into the water stream will be condensed thereby and will, when an ample supply of the exhaust steam is available, impart enough heat to prevent the introduction of harmfully cool water into the boiler.

Should the supply of exhaust steam be insufficient for properly heating the water, or be entirely lacking, as may happen when the engine is drifting, means are provided for introducing live steam to supplement or replace the action of the exhaust steam. Accordingly, a pipe 43 is connected to the steam space in the boiler and to the vacuum chamber in the mixer and is provided with a thermostatically controlled valve 44 Whose temperature sensitive element is disposed in the pipe 42. Hence when the feed water emerging from the Venturi tube is below a predetermined desired temperature, the valve 44 will become opened and live steam will be introduced into the water in amount sufficient to create the water temperature desired.

The exhaust steam which is supplied to the mixer will ordinarily be picked up from the exhaust of the cylinders, a pipe 45 being provided for this purpose and being connected to the cylinder exhaust duct in any suitable manner. The point of connection and the manner of connection are not important. This pipe will preferably be installed, as shown, either on the exterior of the boiler shell, or it may be located inside the front end. At its highest point a vacuum relief valve 46 of ordinary and suitable construction will be installed to admit air to this pipe, should a partial vacuum therein occur. The mixer is connected by a short pipe 47 to the pipe 45.

It is contemplated that when the pump is starting some water will be spilled by the mixer until the velocity of the water jet is sufficient to cause all of the water to bridge the gap and enter the Venturi tube. This spilled water will be allowed to flow into the pipe 48 and will be conducted rearwardly through the check valve 49 preferably back into the feed water supply tank, tender tank or other storage space for feed water, but might be allowed to spill on the ground. Because of the position of the connection of pipes 41 and 45, none of the spilled water may go over into the pipe 45 and enter the engine cylinders. Also the top or the loop in the pipe 45 is high enought so that, when the locomotive is on the steepest downgrade that may be encountered and when the forward end of the locomotive is downhill any water which might flow forwardly through the pipe 48 and leak past the check valve 49 cannot enter the engine cylinders.

The second described form of the invention has the particular advantage of using exhaust steam, a waste product, for raising the temperature of the feed water. When the mixer is properly designed the feed water from the tender tank can be raised in temperature from 32 F. to the saturation temperature of the exhaust steam available for heating.

In the operation of the apparatus shown in Figs. 3 to 6, inclusive, whenever the feed pump is started by opening the steam supply valve located in the cab, the water delivered through the pipe 24 will, in a short time, producev a vacuum in the chamber 28 and draw in exhaust steam and cause it to be mixed in the Venturi tube with the feed water, if exhaust steam is available. Otherwise, in the absence of exhaust steam or due to an insufiicient supply of exhaust steam, the delivery of water into the pipe 42 at a temperature below some predetermined temperature will cause the valve 44 to open up and admit live steam directly from the boiler into the mixer. Hence at all times the apparatus insures that feed water delivered into the boiler will not have a harmfully low temperature. The capacity of the mixer and the supply of steam will be such that enough steam can always be added to sufficiently increase the feed water temperature for the protective purposes desired;

Fig. '7 illustrates a third embodiment of the invention. In this form of the invention the mixer shown in Fig. 5 is employed with the exception that the live steam supply pipe 43 is omitted. This modified mixer is generally indicated as 26 in Fig. '7. The apparatus shown in this figure is intended to replace the apparatus shown in the similar area of Fig. 3, the pipe 24 being connected to the pipe 24, the pipe 48 being connected to pipe 48, 45' to 45, the relief valve 46 being identical with and a substitute for the relief valve 46. In this modification, live steam from the boiler, acting through the pipe 34' regulates the needle valve, while the water is supplied to the mixer from the pipe 24, while the exhaust steam is supplied by the pipe 41'. The Venturi tube 4| is connected to the pipe 42' and delivers the water through a check valve 59, thence into the entering end of another Venturitype mixer which is identical in design with the mixer shown in Fig. 2. This mixer is designated 6' and has a Venturi tube H which delivers the water through the stop and check valve 21' into the boiler.

I3 supplies live steam from the steam space in the boiler to this second mixer. This modified form, therefore, consists substantially of the mixers shown in Figs. 2 and 5 arranged in series, omitting the live steam supply to the exhaust steam mixer and supplying the live steam only into the second mixer. With this arrangement, feed water having a temperature even as low as 32 F. may receive a boost in temperature up to the saturation temperature of whatever exhaust steam is available for heating. Whether or not this water is then sufiiciently heated, it will, in its passage through the second mixer, have its static pressure sufi'iciently lowered so that live steam from the boiler may be mixed thereinto, as will be understood from the previous description of Fig. 2. In the second mixer the water may receive a further boost in temperature which may range up as high as a 150 F. increase, depending upon the proportioning of the parts. Thus when a high pressure boiler is being fed with the apparatus now being described, the feed water temperature may be raised as high as 300 F. and higher, a part of the heat being recovered from the exhaust steam and additional heat being supplied by live steam to make certain that feed water cannot enter the boiler at such a low temperature as to do damage therein.

Referring now to Fig. 3, the pump 22 when running is always delivering a considerable amount of exhaust steam, hence arrangements are herein made to condense that steam by connecting the pipe 5!, as shown, to a jet condenser 52 and causing the exhaust steam to inject water from the pipe 5| into the return pipe 48. Thus the heat of this exhaust steam is saved.

While the invention is illustrated as being applied to a locomotive, it is obviously capable of being used with other boilers, including stationary boilers of various kinds. Furthermore, the drawings and specification illustrate and describe merely a few embodiments of the invention. Va-

A pipe l2 controlled by the valve' riations and other modifications of the invention are contemplated and may be employed without any departure from the spirit and scope of the means including a pump for withdrawing feed I 7 water from a supply source and delivering it at a pressure exceeding the existing boiler pressure, means for temporarily increasing the water velocity and decreasing the static water pressure to a range below the pressure of exhaust steam from the locomotive cylinders, means controlled by the delivery pressure-of said pump for regulating said water pressure and velocity, means for introducing cylinder exhaust steam into said water while at said lowered pressure, and means for decreasing the velocity of the water and raising its pressure after said introduction of exhaust steamto an excess over the boiler pressure and delivering the same into the boiler.

2. In combination with a locomotive boiler, means including a pump for withdrawing feed water from a supply source and delivering it at a pressure exceeding the existing boiler pressure, means for temporarily increasing the water velocity and decreasing the static water pressure to a range below the pressure of exhaust steam from the locomotive cylinders, said means including a nozzle and a valve for regulating the effective area of the nozzle, means controlled by the delivery pressure of said pump foroperating said valve to regulate the flow of water through said nozzle for controlling said static water pres sure, means for introducingcy linder exhaust steaminto said water while at said lowered pressure and means for decreasing the velocity of the water and raising itspressure after said introduction of exhaust steam to an excess'over the boiler'pressure and delivering the same into the boiler.

3. In combination with'a boiler, means including a pump for delivering feed water' at a pres sure exceeding the boiler pressure, a mixer in cluding a chamber, a combining tube and a jet for projecting the water delivered by the pump through the chamber into the tube, means for introducing cylinder exhaust steam into said in the jet, a cylinder having a piston therein rigidly connected with said valve, the side of the piston toward said valve being exposed to the delivery pressure of the pump, a pipe communieating from the steam space in the boiler to the opposite end of said cylinder to subject said piston to the boiler pressure, a pipe connected for delivering water from the pump to the intake end of said jet, and a pipe connected with the combining tube for delivering a mixture of water and steam into the boiler, said piston serving to operate said valve to increase the effective area of the jet as the pump delivery pressure increases and decrease said area as said pump pres sure decreases. V

' VERL' E. MCCOY.

RALPH W. ANDERSON.

' chamber, a needle valve for regulating the orifice

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