US2299033A - Boiler feeder - Google Patents

Description

Oct. 13, 1942. M, E 2,299,033

BOILER FEEDER Filed May 15, 1940 I 2 Sheets-Sheet 1 Oct.' 13, 1.942. M. REED BOILER FEEDER Filed y 1:. 1940 {-63 57 :E 53 I 55 ME 3 as I 29 2 Sheets-Sheet 2 INVENT R 7 11. fix,

ATTORNEYS;

Patented Oct. 13, 1942 iJNlTEE srss parser ore-ice 2,299,033 BOILER FEEDER Llewelyn M. Reed, Devon, Conn.

Application May 13, 1940, Serial No. 334,701

- Claims. (Cl. 122456) This invention relates to a boiler feeder, and has for an object to provide a simple boiler feed system of high thermal efliciency, and also to reduce to a minimum the number of movable parts to thus increase the reliability of operation and decrease cost of installation, operation and upkeep.

Other advantages and objects will be apparent as the description proceeds.

With the foregoing and other objects in view I have devised a construction as illustrated in the accompanying. drawings forming a part of this specification. It will, however, be understood that I am not limited to the exact arrangement and construction shown, but that various changes and modifications may be employed within the scope of the invention.

In these drawings:

Fig. 1 is a front elevation of one embodiment of my improved feeding system with parts broken away to more clearlyshow the construction; and

Fig. 2 is a vertical section through the preferred type of'actuator which may be employed with this feed.

The feeder complete and ready for installation consists of the parts shown in the drawings. It comprises an upright torpedo type body or receiver I!) and a hydraulic actuator i! located outside the receiver. The boiler to which the feeder is connected is shown at [2, but for convenience in illustration and to save space the boiler is shown at considerably smaller scale than the feeder. The steam outlet pipe from the boiler is shown at I3 supplying steam to any use for which the steam is being generated, and the feed water inlet pipe to the boilerv is shown at M. In the present installation this pipe It is connected to the lower part of the receiver w,

and connected to the upper part of the receiver is an equalizing and vent line pipe H5 in which is a control valve [6 which is a combined steam and venting valve, the valve being connected by the steam supply pipe ll to the direct steam suppl pipe I 3. The upper portion of the pipe extends into the receiver l9 and upwardly within the same as shown at IE to discharge into this receiver closely adjacent the top thereof. The valve I5 is operated by hydraulic or fluid pressure on a diaphragm is, and a suitable valve member 29 shifts between upper and lower seats 2! and 22. When the valve is in its lower position on the seat 2| as shown in Fig. 1, the supply of steam from the pipe I! to pipe i5 is cut off, but the opening through the valve seat 221s open the discharge 23. Whenthe valve member 29 is raised under action of spring 24 to carry it against the upper seat 22 the vent is closed, but steam may flow from the pipes H and I3 to the pipe I 5 and be supplied to the upper part of the receiver Ill.

The upper part of the actuator H is connected to the upper part of the receiver In by the pipe 25, while the lower part of the actuator is connected by a pipe 26 with the lower part of the receiver H) through thedischarge pipe M. Within the pipe 26 is a non-return or check valve 2?. Feed water is supplied to' the pipe I from any source of supply through the pipe 28 connected tothe pipe 54 andin which is a non-return or check valve 29. Preferably the pipe 28 is offset downwardly as shown at 39 in which offset the check valve 29 ,is located so that the check valve is always submerged in the water to preventwater hammer. There is also a nonreturn or check valve 3! in the pipe M between the connection of pipe 28 thereto and the boiler E2 to prevent-the boiler pressure forcing water in the boiler back into pipe- Hi. There is a pipe 32 connected to the lower part of the receiver IE3 and, the upper part of the pipe l5 a short distance below check valve 33 in this pipe l5 which is arranged to prevent backflow from the receiver l0 into-the pipe l5. There is also a check valve 34 in the upper part of the pipe 32 to prevent flow from the pipe !5 into the pipe 32.

The actuator I l shown more in detail in Fig. 2 comprises the body 35 within which is a float chamber 36 enclosing a float 31 guided at its lower end for vertical movements by a rod 38 having sliding engagement in a spider 39 at the entrance to the supply discharge pipe 36. At its upper side the float is connected to a head 46 having a vertical elongated slot Al in which is a ro'ller i2mounted in' the body 35 against which presses at. one side a spring 53 which provides suflicient friction to hold the float in its extreme position until the water level in the chamber 36 is at its maximum, or minimum. That is, the coaction of the roller 32 and spring 43 will retain the float in its lowermost position until the water level in the. chamber 35 reaches its. maximum to operate the float to .its uppermost position; After: the float has moved to this uppermost position the. roller 42 and springlll retains it in, this position until the water level in the chamber 36 drops. sufiicient'ly to permit the float to drop to its lowermost position. These retarding operations are .also..assisted. by a spring so that pressure in the pipe l5 may vent through 55 p essed M1144 engaging e e d of t e lever connected to the float at 46 and pivoted to the body of the actuator at 41. The end of the lever has surfaces 48 and 49 at different angles against which the ball 44 seats. When the float is in its uppermost and lowermost positions the ball is pressed against these surfaces of the lever by the spring 50 tension of which may be adjusted by a screw 5| to control the times of operation of the float.

Lever 45 operates two control valves 52 and 53 which are shown as ball valves normally held on their seats by springs 54 and 55 respectively and may be lifted from these seats by the lever 45 through slidable rods 56 and 51. The valve 52 controls the supply of fluid pressure from a supply pipe 58 to the pipe 59 connected with the pipe 60 which is connected to the casing BI of the valve I6 above the diaphragm I9. A branch 62 of the pipe 60 leads to the valve 53 from which extends a vent pipe 63. When the float 31 is in its lowermost position as shown in Fig. 2 the vent valve 53 is closed and the hydraulic or fluid pressure supply valve 52 is open permitting supply pressure from pipe '58 to pass to pipe 69 and diaphragm I9 to force valve member 20 downwardly to the position shown in Fig. 1 to close the steam supply pipe H and open the vent from the pipe I5 to pipe 23. When the float is in its upper position the fluid pressure supply valve 52 is closed and the vent valve 53 is open permitting the pipe 60 to vent through the pipe 63 thus reducing the pressure on the diaphragm I9 and permitting the spring 24 to shift the valve member 25 against valve seat 22 permitting flow of steam from pipe IT to pipe I5 and cutting off communication from pipe I5 to vent 23. The check valves 33 and 34 are provided with small vent openings 64 and 65 respectively passing through the valves for venting purposes which will presently be described.

For the best and most eflicient operation the arrangement of the piping connections is very important, although of course they may be varied. Also the location of the various check valves is important as well as the type and quality of these valves. Of course the cost of the equipment varies with the type of materials used. The cheapest units are those where standard piping, fittings, etc. may be used with a welded steel receiver, but the best quality of materials should be used in the actuator and the steam supply and vent valve I6.

In operation the receiver II) is filled through the connection 28 either from a suitable receiver for feed water or from direct lines which convey condensate, makeup water, etc. This water cannot enter the actuator II from the pipe I4 because of the check valve 21, but it may flow by pipe I4 into the receiver I because the steam pressure to the pipe I is out oil by the valve 20 and the pipe I5 is connected to and venting through the pipe 23 and the top of the receiver I0 is venting through the opening 64 in check valve 33. The receiver It will receive this feed water until filled to the overflow point 25a where the pipe 25 from the top of the actuator is connected to the receiver. When the water reaches this level it flows through pipe 25 to the float chamber in the actuator I I, and during the short space of time required for the actuator to function, by rising of the float 31 to open the vent valve 53 and close the pressure supply valve 52 and thus permit steam valve 20 to open, water may continue to flow into the receiver I0, sufficient space being provided above the connection 25a so that there will always be a little steam space at the top of the receiver when the steam valve 20 opens. However, the feeder will function even though the receiver is completely flooded with water. Should this happen check valve 33 prevents the feed water passing out pipe I8 and flooding pipe I5. As described, when the water overflows through 25 into the actuator float chamber the float rises and through the operation described opens the steam valve 20 to permit steam to flow from the pipes I3 and Il into pipe I5 and through I8 into the top of the receiver III. Thus steam direct from the boiler enters the top of the receiver, and because of the proper design and proportion of the areas of the steam supply pipe and the receiver equalization of pressures in the boiler and the receiver takes place quickly, yet gradually enough to prevent shock. As soon as this equalization of pressures in the boiler and the receiver takes place the water in the receiver flows by gravity through the pipe I4 and outlet check valve 3| to the boiler. This discharge rate will be in direct proportion to the gravity head available and. to the piping arrangement between the receiver and the boiler which should be such as to reduce friction to a minimum. Also, the receiver should be located as high above the boiler as possible to get as much gravity head as possible. A tall receiver helps to increase the head and capacity or volume.

As the water flows out of the receiver I0 it also flows out of the float chamber in the actuator I I. However, the resistance through the check valve 21 in the outlet 26 from the actuator provides the necessary delay in emptying the actuator so that the receiver will entirely empty. When the actuator chamber is empty or nearly so the float 31 falls to its extreme lower position allowing the hydraulic vent valve 53 to close and opening the hydraulic or fluid pressure valve 52 thus applying pressure to the diaphragm I9 and shifting the valve 20 to its lowermost position cutting off supply of steam from the pipe I1 and opening the vent from the pipe I5 to pipe 23. Pressure in the receiver I3 is thus relieved through the pipe I5 and the vent through the valve seat 22 until thepressure in the receiver I0 is less than in the feed. water supply line 28 at which time water again flows from the feed water supply line 28 into the receiver I0 and the cycle repeats itself as long as and whenever there is water to be handled. The supply of feed Water through the pipe 28 is controlled by a'suitable feed water regulator (not shown) toautomatically maintain the water level in the boiler at the proper point. The preferred form of feed water regulator is shown in my copending application Serial No. 348,703.

It is also desirable to have an equalizing pipe line 66 connected with the upper part of the float chamber in actuator I I, and with pipe I5 behind the steam control valve I6. This carries off pressure due to flash in the actuator I I. Without this the actuator might be slow in filling and the body I0 of the feeder become flooded.

The capacity of this feeder will depend on the number of cycles per hour and these will depend upon how quickly the receiver can be filled, how much gravity head is provided, and how good the piping arrangement is. It is very important for most efficient operation that there be a direct live steam line from the boiler to the receiver independent of other lines. The small vent hole through the disc of the check valve 34 is to allow suificient steam to enter to break the column in the pipe 32 as the water runs from the bottom of thereceiver tank l0.v Whenthesteam valve 20 closesand pipe, I5 is placed in communication with pipe 23 so as to vent through this pipe when the water level in the pipe 32 and the tank [0 reaches the lower end, of this pipe, pressure in the tank, it will blow off through the pipe 32 carryin out, air and free oxygen through the pipe,32;to the venting pipe I5. Also, the small vent 64 in the check valve 33 permits venting of air fromthe very top of the receiver. This per-.

through connection H3. The lag between fillings of tank Hi is thus greatly reduced giving more rapid actionand increasin the boiler feeding capacity of the device. In other words the purpose of pipe 32 is to permit discharge of the greater bulk of the gasesunder pressure in receiver H3 at the end of the cycle of operation, thereby removing a large percentage of the air which, due to its relative weight, is at the lower part of receiver iii, and isthus for de-aeration. In prior devices feeding boilers by a similar method discharge takes place through a connection similarto pipe it or near the top of the equalizing receiver, and therefore the air expands; with the water vapor and only a small percentage of it is actually removed. Finally the accumulation of air or oxygen becomes so great that a certain quantity is captured by the water being discharged to the boiler. With pipe 32 the air or oxygen being the heavier of the two elements. is really blasted or forced out of the lower part of receiver 5 9 by the force of the steam above. The orifice G5 in the check valve 34 is preferably relatively small, as a rule not over or just enough to allow equalization of steam pressure in pipe 32 so water will flow out of the same when it flows out of receiver It. This orifice should not be a large one, and the check valve at this point prevents extreme commotion, particularly at a time when the water in receiver it is below the boiling point, and this occurs at starting up periods and when new steam is turned on new equipment and slugs of cold return water come through. As

the overflow from the receiver Ii! when it fills: r

through the pipe 25 is to an actuator which is in a separate vessel it gives rapid action which would not be possible if the actuator were in the receiver. The actuator II and steam valve l6 control shown are important as insuring positive operation of the steam valve, and also insuring sub-- stantiallycomplete filling and emptying of the receiver on each cycle thus giving maximum capacity.

The cross sectional area of the receiver i0 is: relatively small with respect to that of the steam supply pipe 5 to thus reduce the rate of surface condensation, and because of this giving much more rapid equalization of pressures in the receiver and the boiler permitting the use of smaller steam'supply pipes and requiring much less steam. for operation. For effective operation it has been found that a one inch steam supply pipe is sufficient for a ten inch diameter cylindrical tank It.

The relatively small cross sectional area of re,-

ceiver l0 torthe area of discharge pipe, I4 is also.

important as it permits rapid discharge with little tendency to swirl, which would both retard discharge and create a funnel which would entrain air, and thereby carry it into the boiler.

To get the highest thermal efliciency in boiler feeding, which is a large step toward heat balance in a steam plant, the hottest Water available must be used for feeding, and of course the right quantity must be fed to meet the load demands, and the problem of heat balance. in the boiler feed system itself is very important. This system when properly applied to a steam plant will be Very efficient as compared with other systems because the only thermal losswill be that due to radiation and this quantity will depend upon the sort of insulation employed. for the various pipes and receiver tank. And whereas by other methods of boiler feeding from 2 to 8 percent of each boilers generated energy is expended solely for feeding the makeup water to it, this system does not use over one-half of one percent of each boilers generated energy. The upkeep cost is very low as compared with pumps and other .similar apparatus, and the energy expended in pumping to overcome friction in the pump itself and to force the water against boiler pressure and against excess pressure for feed regulation does not enter into the problem of feeding by this improved system. The loss of this energy is a complete Waste, and there is a material saving of maintenance cost of this system over such systems as employ pumps and similar apparatus. This improved system is fully automatic, safe and dependable. The design of this system is so flexible that the right size unit or size and number of units can be installed at a very reasonable cost.

As previously suggested this improved system includes in addition to this feed water system a feed water regulator (not shown) which is either to control the makeup water or to control its discharge to individual boilers whichever may be the most practical, these feed Water regulators operating on changes in the water level in the boiler to control the amount of feed water fed to the boiler to maintain this level constant. If the system is used in a plant where there is low pressure condensation available and which would have to be elevated where it may enter the receiver, a suitable type of booster may be employed for this purpose. If the available makeup water in the plant is under suflicient pressure so that it will flow to the receiver another saving is effected. If hot makeup water is available so much the better, but in any case care must be taken to see that all of the feed water which is usually made up of a combination of high pressure returns, low pressure returns and makeup water, is of the highest temperature available, and this can be accomplished by conducting the lowest temperature water or condensate through some heating device, usually a closed type feed water heater, although it is just as practical in many cases touse an open type heater into which the vents from the feeders and boosters are exhausted and from which the heated water is drawn, and elevated to the receiver or receivers. All these points are very important, and if best results are to be obtained each plant should be treated as an individual case and everything be brought into coordination in accordance with the above mentioned factors.

Having thus set forth the nature of my invention, whatI claim is:

1. In a boiler feeder, an upright receiver tank located above the boiler, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe to connect the steam space with the tank in one position and to vent the steam pipe in its other position, a connection from the lower part of the tank to the steam pipe adjacent the upper part of the tank, a check valve in said connection, an actuator outside the tank comprisinga float chamber, a connection from the upper part of the chamber to the upper part of the tank, a connection from the lower part of the chamber to the outlet from the tank, a float in said chamber, means operated by the float to control the control valve, and a feed water supply pipe connected to the outlet from the tank, and check valves in the outlet from the actuator and in the connection from the tank to the boiler.

2. In a boiler feeder, an upright receiver tank located above the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe to connect the steam space with the tank in one position and to vent the steam pipe in its other position, a connection from the lower part of the tank to the steam pipe adjacent the upper part of the tank, a check valve in said connection, means dependent on the level of water in the tank to control opening and closing of the steam valve, a feed water connection from the tank to the boiler and a check valve in said connection.

3. In a boiler feeder, an upright receiver tank located above the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe to connect the steam space with the tank in one position and to vent the steam pipe in its other position, a feed water connection from the lower part of the tank to the boiler and a check valve in said connection, a connection from the lower part of the tank to the steam pipe adjacent the upper part of the tank, a check valve in said connection having a small vent opening therethrough, and means connected with the tank having operating means dependent on the level of water in the tank for controlling opening and closing of the steam valve to equalize pressures in the tank and boiler when the tank is filled and shut off flow of steam to the tank when the tank is empty.

4. In a boiler feeder, an upright cylindrical receiver tank located above the boiler, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe, an actuator outside the tank comprising a float chamber, an overflow connection from the upper part of the tank to said chamber, a connection from the lower part of the chamber to the outlet from the tank, a float in said chamber, means operated by the float to control operation of the steam valve, a feed water supply connected to the tank, the cross sectional area of the tank being relatively small with respect to that of the steam pipe to reduce the rate of condensation of steam supplied to the upper part of the tank and also relatively small with respect to the area of the outlet connection from the tank to the boiler, a check valve in the outlet from the actuator, and a check valve in the outlet connection from the tank to the boiler.

5. In a boiler feeder, an upright cylindrical receiver tank located above the boiler, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe to control supply of steam to the upper part of the tank in one position and out off steam from the tank and vent the steam pipe in its other position, a venting pipe connection from the lower part of the tank to the upper part of the steam pipe, an actuator outside the tank comprising a float chamber, an overflow connection from the upper part of the tank to said float chamber, a discharge connection from the lower part of the chamber to the outlet from the tank, a check valve in said connection, a float in said chamber, means operated by the float to control opening and closing of the steam valve, a feed water supply connected to the tank, and a check valve in the outlet connection from the tank to the boiler.

6. In a boiler feeder, an upright receiver tank located above the boiler, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe, an actuator outside the tank comprising a float chamber, a connection from the chamber to the upper part of the tank, a connection from the lower part of the chamber to the outlet from the tank, a float in said chamber, means operated by the float to control the control valve, an equalizing pipe line connected with the upper part of the float chamber and with the steam pipe connection behind the control valve, a feed water supply pipe connected to the outlet from the tank, and check valves in the outlet from the actuator and in the connection from the tank to the boiler.

'7. In a boiler feeder, an upright cylindrical receiver tank located above the boiler, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe, an actuator outside the tank comprising a float chamber, an overflow connection from the upper part of the tank to said chamber, a connection from the lower part of the chamber to the outlet from the tank, a float in said chamber, means operated by the float to control operation of the steam valve, an equalizing pipe line leading from the upper part of the float chamber to the steam pipe behind the control valve, a feed water supply connected to the tank, a check valve in the outlet from the actuator, and a check valve in the outlet connection from the tank to the boiler.

8. In a boiler feeder, an upright receiver tank, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe to connect the steam space with the tank in one position and to vent the steam pipe in its other position, a connection from the lower part of the tank to the steam pipe adjacent the upper part of the tank, a check valve in said connection having a small vent opening, a check valve in the steam pipe connection between its connection to the tank and the connection from the lower part of the tank and having a vent opening therein, a feed water supply connected to the tank, and means dependent on the level of water in the tank to control opening and closing of the steam valve.

9. In a boiler feeder, an upright receiver tank, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a check valve in said connection adjacent the tank having a vent opening therethrough, a control valve in said steam pipe to control connection of the steam space to the upper part of the tank in one position and to vent said steam pipe in its other position, a venting pipe connection from the lower part of the tank to the upper part of the steam pipe between the check valve and the control valve, a check valve in said venting pipe having a vent opening therein, an actuator outside the tank comprising a float chamber, an overflow connection from the upper part of the tank to said float chamber, a discharge connection from the lower part of the chamber to the outlet from the tank, a check valve in said connection, a float in said chamber, means operated by the float to control opening and closing of the control valve, and a feed water supply connected to the tank.

10. In a boiler feeder, an upright receiver tank, an outlet connection from the lower part of the tank to the boiler, a steam pipe connection from the steam space in the boiler to the upper part of the tank, a control valve in said steam pipe, an actuator comprising a float chamber, a connection from the chamber to the upper part of the tank, a connection from the lower part of the chamber to the outlet from the tank, a float in said chamber, means operated by the float to control the control valve, an equalizing pipe line connected with the upper part of the float chamber and with the steam pipe connection behind the control valve, a feed water supply connected with the tank, and check valves in the outlet from the actuator and in the connection from the tank to the boiler,

LLEWELYN M. REED.

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