US1921498A - Feed water regulator - Google Patents

Description

Augo 8, 1933. V J BARRETT I 1,921,498

FEED WATER REGULATOR Filed Aug. 50, 1928 2 Sheets-Sheet 1 26 INVENTQR 7 z W ?7/p4 ATTORNEYS Aug. 8, 1933. J BARRETT 1,921,498

FEED WATER REGULATOR Filed Aug. 50, 1928 2 SheetsSheet 2 Patented Aug. 8, 1933 FEED WATER. nrcom'ron Joseph M. Barrett, Cleveland Heights, Ohio, as-

signor to Bailey Meter Company, Cleveland, Ohio, a Corporation of Delaware Application August 30, 1928.

27 Claims.

This invention relates to boiler feed water regulators of the generator type, in which the flow of water to the boiler is governed by the effect of a generator spanning the desired water level and in which a trapped quantity of liquid is vaporized or condensed according to variations in water'level, to produce varying pressure effects, which are transmitted to and are effective upon the feed water regulator or valve.

One object of the invention is to provide a sensitive generator, in the sense that it avoids the usual delays and is very quickly responsive to both rise and fall in water level, thereby avoiding a sudden drop by immediately increasing the water supply to the boiler, and by prompt reduction in the supply preventing a sudden rise, which might flood the boiler or carry entrained water into the steam mains.

A further object is to provide a. generator which is readily adjustable to-secure any desirable normal water level, and particularly is adjustable by relative motion between the trapped generating chamber member containing the trapped liquid and its cooperating pipe or conduit containing a water column in communication' with the water and steam spaces of the boiler.

Another object is to provide a generator type regulator including a conduit adapted for connection to the boiler in a standard position and having connected in circulating communication therewith a pipe forming a part of the generator and so fixed in a predetermined definite relation to said conduit that when the pipe and conduit are assembled in unit form they are incapable of relative adjustment, enabling the unit to be constructed and shipped to the job and there installed in the standard position with the certainty that the said pipe will bear a definite relation to the boiler and insuring the most effective and desirable operating conditions.

Still another object is to take advantage of the adjustability of the generator or its parts as a control for the normal water level, for the purpose of harmonizing the rate of water feed with any variations in pressure differential between the boiler pressure on the one hand and the steam supply main pressure on the other hand, including pressure drop through a superheater if used, all for the purpose of maintaining a proper proportioning of the water supply to the steam load without undesirable variations in normal Water level, such as are encountered in modern high pressure boiler systems, where at best the total volume of water in the Serial No. 302,967

boiler is always small and flash boiler conditions are approximated.

Another object of the invention is to safeguard the boiler in emergencies by the provision of a. Improved by-pass mechanism for fully opening the water regulating valve to supply any sudden or emergency deficiency.

b. Means operated or controlled in accordance or in harmony with the presence or absence of fire in the boiler for increasing the water feed rate, to compensate for the usual very sudden drop in water level when the fire goes out, or under like emergency conditions.

0. By-pass mechanism for controlling operation of the adjustable generator to secure emergency operation of the water regulating valve when necessary.

Other objects of the invention are to improve various features of the mechanism and system, including the provision of a special improved arrangement of by-pass mechanism for the water regulating valve, enabling it to be suddenly opened manually when desired; the use of expansible metal bellows for valve operation instead of the usual diaphragms, avoiding all disadvantages of diaphragms; and the protection of the expansible metal bellows, when controlled by the vaporization of trapped liquid, by such proportioning and arranging of parts as will prevent bellows expansion to or beyond the normal elastic limit, or, in other words, by the use of expansion bellows of over-capacity, to prevent injury thereto; as Well as improvements in the valve discs or other valve members so as to graduate the action and secure increased efiiciency.

Still another object of the invention is to provide improved pressure differential valve mechanism in the water supply main ahead of the water regulating valve, together with generator control thereof under emergency conditions, so as to provide maximum water supply to the regu-. lating valve in emergencies and avoid the usual restriction and reduction in flow when maximum flow is desirable, together with by-passing mechanism for the pressure difierential valve actuated either manually or automatically as desired.

Still other objects of the invention are in part obvious and in part will appear more in detail 1 from the description hereinafter. 05

In the drawings, Fig. 1 represents a diagrammatic elevation of one arrangement of feed water regulating mechanism embodying the invention; Fig. 2 is a sectional elevation through the two no generators and their connected parts shown in Fig. 1; Fig. 3 is a sectional elevation of a by-pass or controlling valve; Fig. 4 is a detail sectional elevatio of part of the pressure differential operating echanism for the normal control generator; Fig. 5 is a detail longitudinal section illustrating the water regulating valve and its operating mechanism; Fig. 6 is a similar view of the pressure differential valve mechanism ahead of the water feed regulating valve: Fig. '7 is a detail view illustrating a modified operator for the by-pass mechanism; and Fig. 8 is a detail section view on a larger scale, of the graduating means for the pressure differential valve.

In the drawings, 1 represents conventionally any suitable boiler in which it is desirable to maintain the normal water level indicated at A. 2 is the water feed main, 3 the Water regulating valve or regulator therefor, and 4 is the pressure difierential valve in the Water line ahead of the regulator 3.

The generator for controlling the water regulator 3 is indicated generally at 5. It is of the type in which a trapped chamber containing a suitable vaporizable liquid, such as water, is laid across or spans the normal water level, preferably being set on an incline for Well known reasons, and is in'contact or suitable cooperating heat conducting relation with a pipe or conduit 6 containing a water column in communication with both the steam and water spaces in the boiler. In the arrangement shown in Fig. 2 the chamber containing the vaporizable liquid is contained within a member 7 which is bodily adjustable vertically or longitudinally along the pipe 6, such as by being formed of concentric inner and outer tubular shell members 8, 8a with an annular cylindrical trapped chamber 9 between them closed at its ends by the flanges 10, which may be welded or otherwise connected to said tubular members. The outer shell member is finned or otherwise provided with heat radiating means 11, as is usual, and at each end the adjustable member 7 may be provided with extended dust guards 12 which move with it along the pipe 6. The trapped chamber 9 communicates by a relatively small pipe 13 with suitable motive means for the regulator 3, as will appear.

Pipe 6, with its water column in communication with both the water and steam spaces of the boiler, is usually set at an incline for amplifying the heat transfer effects, and may be connected anywhere to the boiler or its piping system. Preferably, however, the generator is constructed as a unit adapted for standard connection to any part of the boiler system so that upon installation at known or definite level an unskilled operator will be certain to place it in the proper and most eflicient position. This unit includes a vertical pipe 15 provided at its upper and lower ends with suitable connecting means, such as the angle valves 16, 17, adapted for connection to the boiler system, such as to the pipes 18, 19 communicating with the boiler above and below the water line and leading, for example, to the usual gauge glass. The pipe 15 serves as a base to which are fixedly connected, as by welding, the upper and lower ends of the pipe 6, so that to install thegenerator unit it is only necessary to set the supporting base pipe 15 with its axis vertical and connect its members 16, 17 to the boiler system in such manner that the inclined portion of the pipe 6 is at the prescribed level with respect to the desirable normal level A of boiler water. The pipe 15 therefore forms a base for supporting all of the generator parts and of the generator unit are fixed to each other so that when in assembled relation they are incapable of relative adjustment. Installation of the generator unit with pipe 15 in standard position or relation to the boiler therefore insures a predetermined definite relation of pipe 6 to the boiler, so that the engineer or boiler operator cannot disturb the relation between the two pipes or of pipe 6 to the boiler, thus insuring the most efiicient and satisfactory operating results.

The water regulating valve 3 is of the usual balanced type with its stem 20 subjected to the influence of a compression spring 21 whose tendency is to move the valve to closed position, or to the left in Fig. 5. The stem is also subject to the effect of a movable abutment 22 at one end of an expansible metal or sylphon motive bellows 23 communicating with pipe 13 before referred to. It may be assumed that the pressure differential valve 4 delivers to valve 3 water at a definite pressure value above the boiler pressure. During normal boiler operation the water column in pipe 6 stands at Water level in the boiler, so that both steam and water zones are opposite the liquid in the trapped generator chamber 9, vaporizing some of the water therein and exerting a pressure effect through tube 13 upon the bellows 23, preponderating spring 21 and moving over the valve more or less to open position, thereby supplying water in accordance with or in step with the rate of steam production. The rate of water feed is therefore a function of the pressure in tube 13, which depends upon the amount of liquid vaporized or condensed in .the trapped chamber 9. This in turn is dependent upon a number of factors at the generator, due to the rise and fall of the water column in pipe 6 and the consequent increase or decrease in the relative areas of the steam and water zones in said pipe effective upon the liquid in the trapped chamber. Upon fall in boiler water level the steam zone effective upon the trapped chamber is increased, more water in said chamber is vaporized, and the pressure in the bellows is increased to additionally open the regulating valve 3.

In these Water regulator valves it is usual to provide by-passing means, to wit, some arrangement by which the valve mechanism may be manually moved to wide open valve position so as to promptly cope'with emergency conditions requiring an increase in the water supply upon failure of some of the mechanism or for other reasons. Such by-passing means usually comprises a rotatable nut or the like, sometimes requiring from thirty to sixty tugs or operations of the operating wheel, practically impossible to accomplish in the thirty to ninety seconds available under present boiler conditions. I therefore provide the water regulator valve with improved by-passing means, including a collar or abutment 71 on the valve stem opposite which is a cam '72 on a shaft 73 mounted in a suitable frame bearing and provided with operating means on its outer end, such as the hand lever 74, or; as shown in Fig. 7, the sheave or sprocket wheel '75 over which an endless chain '76 may pass.. Rotation of the hand lever '14 through 180 or like operation of he sheave or sprocket '75 completely opens t e water regulator valve and secures maximum water flow. The sprocket wheel and chain are particularly valuable when the water regulator valve happens to be fifty feet or so above ground level on a modern boiler with high setting, because the endless chain may be permitted to hang down the full fifty feet and be accessible from any level for immediate emergency operation, without running up or down stairs. If desired, the valve stem or any part moving therewith, such as the abutment 71, may be provided with an extension 71a serving as a pointer travelling along a scale 71b on the frame to visibly indicate the actual valve position.

It is desirable upon fall in the boiler water level to secure immediate response by increase in the water feed, without retard due to sluggish flow of pressure from the generator chamber to motive bellows. Usually in these devices the pipe 13 has been made one-eighth inch I. D. In the present construction the pipe 13 is made at least one-quarter inch 1. D., with the ability to pass the wave of pressure to the bellows four times as fast as in prior constructions. Therefore, increase of water feed is considerably more rapid by the present mechanism than in prior constructions.

Moreover, to avoid flooding the boiler or any such increase in the water flow as might raise the water level in the boiler to a point where water is carried over entrained with the steam, it is desirable upon abnormal rise in water level to promptly reduce the rate of water flow. Reduction in water fiow is secured in these generator regulators by the rise of the water column in pipe 6, the corresponding reduction in the steam zone efiective upon the trapped generator chamber, and the cooling effect of the rising water column and consequent condensation of the vaporized liquid in the trapped chamber. To secure prompt response to a rise in water level I provide the pipe 6 at its upper end with a gooseneck 24 and at its lower end with a depending loop or trap portion formed by a relatively large hollow well or reservoir member 25 finned or otherwise provided with heat radiating means 26 and provided with a blow-01f pipe 2'7 at its lower end. The pipe 6 extends down to and is open at the bottom of the well 25 and the latter communicates at its upper end with the vertical pipe 15. The trap or loop in pipe 6, including the well 25, is below the point where the pipe 6 communicates with the water space in pipe 15, and hence always remains full of water even though the water level in the boiler drops abnormally to a level below said point.

During normal operation the well is entirely full of water, which is at a relative low temperature, due to heat radiation from its fins. The goose-neck 24 contains a length of pipe which is longer or at least as long as the inclined part of pipe 6 opposite the trapped chamber 9, and the well in the downwardly extending loop or'trap has a capacity at least as great as said inclined part of pipe 6.

Assuming the water level to rise in the boiler it finally, upon abnormal conditions, reaches the mouth 28 of the gooseneck, sealing said mouth and trapping vapor in the gooseneck. Such vapor promptly condenses, producing a vacuum effect and drawing in liquid from pipe 15 on the one hand and upwardly in pipe 6 on the other, with a rise of liquid in pipe 6 to a point above boiler level. This draws into the inclined generator part of pipe 6 the cooler water from the well 25, which immediately exerts its effect upon the vapor in the trapped chamber 9, condenses the same and reduces the pressure on the motive bellows, so thatthe valve 3 promptly moves over toward closed position. In ordinary operation the water may rise by two or three spurts, intermittently sealing the mouth 28 of the gooseneck and at first dragging up a small quantity of waterfrom the well 25, followed by a drop in water level in the pipe 15, opening of the mouth 28, and then a like series of steps until finally a full column of cooler water is raised in pipe 6 and the valve 3 is adjusted to meet the new condition. The action may be by separate impulses but is rapid and promptly responds to an abnormal rise in the water level. The pipe 15 may be provided with a restriction, as shown at 100, Fig. 2. The throttling effect of this restriction not only tends to prevent upward spurts or surges of the water in pipe 15, such as might prematurely seal the mouth of the .gooseneck 24, but it also has a tendency to increase effectiveness of the gooseneck 24 upon emergency rise in water level. When this occurs and the mouth 28 of the gooseneck is actually sealed by the rising water, the condensing effect occuring in the gooseneck is applied more efiectively through the pipe 6, which is not throttled, than it is through the pipe 15, which is throttled at 100, so that upon the production of a condensing effect the water rises more readily through pipe 6 than through pipe 15, with an increased tendency to convey to the generator parts the cooler water of the well 25.

The expansible metal bellows 23 does away with many objections to the leather or other diaphragms ordinarily used for operating these regulator valves. A diaphragm in one position lies in a flat or plane surface and upon increase in pressure it bulges out to concave-convex form, but the amount of motion at the crest of its arch, where it is eifective upon the valve stem, is very materially out of step with uniform variations in the liquid column in the trapped generator chamber. In other words, assuming three successive inches of variation of said liquid column, the first inch of such variation produces diaphragm motion considerably different from that produced by the last inch of column travel.

Further, diaplrragms when new have a certain resistance to flexing movement, which decreases with age, in addition to which they are difficult to hold tight, due to the creeping of the rubber at the binding edge when under compression. When they stretch, their contact area with the stem varies. A metal bellows may now be made so that within reasonable limits its longitudinal expansion is substantially proportional to the increased volume crowded into it, and within reasonable limits it can be flexed back and forth many times, even millions, without exceeding the fatigue limit of the metal. Bellows 23 is therefore so made as to provide substantially uniform valve motion for uniform variation in level of the water column in pipe 6. Moreover, to protect it against injury I preferably so relate each bellows to its trapped chamber that the bellows will accept all of the liquid in the trapped chamber before the bellows has been expanded beyond its elastic limit. In other words, the bellows is of over-capacity. Therefore, if the water level in pipe 6 drops to a point where suflicient liquid is vaporized in the trapped chamber 9, all of the water therein will be forced over into the pipe 13 and thence into the bellows, leaving the trapped chamber 9 filled with vapor. This is the maximum condition and produces maximum feed water supply from this source of water regulation. The heat transfer from the steam in pipe 6 to the vapor in the trapped chamber 9 can have no material expansive effect upon the bellows. Therefore, the latter is protected against the injury ordinarily encountered in the usual generator controls, where the trapped chamber 9 is never fully evacuated of water. In these controls for high pressure boilers, assuming a boiler built to withstand one thousand pounds per square inch, for example, it is easily possible to build up nine hundred and eighty or more pounds pressure per square inch. On a diaphragm having an area of twenty square inches, the valve and yoke structure would therefore have to be built to withstand a total of nineteen thousand six hundred pounds stress, a structure out of all proportion to the size. My metal motive bellows is never subjected to these high stresses and the valve frame and parts can therefore be made of reasonable and in fact minimum proportions.

In these regulators it is also desirable to properly proportion the feed water supply to the steam demand or load. The latter is roughly proportional to the relation between the boiler pressure and the pressure at the steam supply main, or in other words, to the steam pressure drop. If a super-heater is used there is an additional pressure drop. Accordingly, I provide means sensitive to the steam pressure drop and adapted to provide additional water supply if the pressure drop increases, or, in other words, as there is a greater demand for steam. This I accomplish, in the instance shown, by taking advantage of adjustability of the generator. It has been stated that the two parts of the generator, to wit, the member containing the trapped chamber 9 and the pipe 6 containing the boiler water column, are relatively adjustable. Of course, they may be relatively adjusted by hand in the initial installation, or from time to time, to secure any desirable water level. In the present instance I automatically adjust the two parts relatively so that when the pressure drop increases or the steam demand increases there is an adjustment of the generator to cause additional water supply, or in effect, to raise the apparent desirable water level in the boiler.

Adjustability of the generator is secured by moving the trappedchamber unit 8 relative to the pipe 6, and specifically along the same. I provide mechanism for so relatively adjusting these parts, such as a pair of cables 30 each connected at one end to one of the'arms of a pivoted lever 31, said cables passing over idler pulleys or sheaves 32 and then in opposite directions to the two ends of the adjustable generator member 7, where they are fastened. The lower ends of the cables may be secured to the lever arms at different distances from the pivot, such as by being fastened to members 33 which are adjustable longitudinally in slots 34 of the lever and are suitably adapted for securement by set screws, clamps or the like, in any position along said slots.

I also provide means for actuating the lever 31. The means shown comprises a movable abutment, such as a metal bellows 35 contained within a hollow casing 36 upon a bracket 37 on which the lever 31 may be pivoted. One end of the bellows is fixed and its opposite end is clamped by the nut 38a to the head 38b of a rod 38 connected by a link 39 with one arm of the lever 31. The chamber within the bellows communicates by a pipe 40 with the steam supply main 41, which may be in communication with the super-heater, if one is used, while the chamber on the outside of the bellows but inside of the casing 36 communicates by a pipe 42 with the boiler 1, such as with the water pipe 19, in the instance shown. Bellows 35 is subject to the effect of a compression spring 43, which at one end lies opposite the head 38b and at its opposite end is suitably attached to a nut 44 threaded upon an adjusting screw 45 having a collar 46 seated in a recess of the casing, said nut being non-rotatable and suitably guided, as by the posts 47.

By screwing up the nut until the spring is in contact with the head 38b, the device may be set so that the bellows will slowly compress through its full travel, as the pressure differential of the boiler over the steam main increases, or, it can be set in the position shown in Fig. 4, so that the differential can increase to a certain value before the bellows starts to contract. However, the main object is to provide an increase in water feed rate with an increase in steam load, all without undesirably lowering the water level in the boiler. In operation, as the steam pressure drop increases the bellows 35 finally moves over and swings the lever 31, producing through the cables 30 a pull on one end of the adjustable generator unit and moving the same upwardly along pipe 6, thereby increasing the steam zone eifective upon the trapped generator chamber with an immediate opening movement of the valve 3 by the production of the necessary pressure in the sylphon bellows 23, to provide additional water supply. When the pressure difierential drops the bellows 35 moves in the opposite direction, lever 31 is swung back in the opposite direction, the generator unit is moved downwardly, the effective water level in the boiler is dropped, and the valve 3 is more or less closed. This arrangement automatically lowers the effective water level in the boiler or in other words, increases the rate of water supply to meet an increase in the demand for steam. In its absence, as in prior constructions, it is usually necessary to permit the water level to drop several inches before there is an increase in the steam zone effective upon the trapped generator chamber 9 to cause additional opening movement of the valve 3. The present arrangement promptly in- 180 creases the generator steam zone upon a sudden demand for steam.

The arrangement so far described automatically adjusts the generator as the steam load varies. It is also possible to utilizethe same or similar mechanism for emergency conditions, such as when the fire goes out, the fuel feed is stopped, or the like. Electrically operated feeders for pulverized fuel sometimes suddenly cease operation if their current supply is cut ofi. Pumps for oil or gas fuel may suddenly stop. Under these or any other similar conditions the effect in the boiler is for the water level to very suddenly drop, a condition which demands an immediate copious water supply to bring its level up to the proper point. Therefore, I also may control the automatically adjustable generator in a manner to meet such emergency conditions, particularly by controlling the actuator therefor, to wit, the expansible bellows 35. This I accomplish by including in the conduit 40 leading to the super-heater or other steam supply main, valve mechanism which upon the occurrence of emergency conditions interrupts said communication and opens the low pressure side of the bellows to a reduced pressure, such as to at mosphere. Such an arrangement is shown in Fig. 3. In the pipe is included a valve marked generally 40a. On one side of a through opening in a cross wall 400 thereof said valve communicates by a pipe 40a with the chamber in bellows 35, while on the other side of said opening the valve communicates by the pipe 40b with the steam main or super-heater. The bellows side of the valve also communicates by a port 40w with a reduced pressure, such as atmosphere. In said valve is a double ended valve member 40:0 adapted in its upper position, shown in Fig. 3, to close the opening in the cross wall 402) and thereby interrupt communication from the bellows 35 to the steam main and at the same time open the bellows to communication with atmosphere through the port 40112, and in its lower position to close the atmospheric port 40w and open communication from the bellows to the steam main or super-heater. This valve member has a stem 48 subject to a compression spring 49 tending to move it to the first of said positions. Means is provided for moving the valve against the efiect of said spring to the other of said positions, and such means is subject to or influenced by the emergency condition it is designed to safeguard. For instance, some condition occurring simultaneously with the existence of a fire in the boiler is utilized to oppose said spring and move the valve to the second of said positions. The current supplying power for actuating a pulverized fuel feed mechanism or motors for actuating gas or liquid fuel pumps may be used to actuate a solenoid or magnet opposing the effect of the spring 49, so that when the current operating said fuel feed devices ceases, the magnet is deenergized and the spring 49 moves the valve to the upper or emergency position. In the arrangement shown, the condition utilized is the air pressure in the furnace chamber, as the result of the existence of fire therein. The valve stem 48 beyond the spring 49 extends into achamber 50 where it is connected to a diaphragm or other abutment 51 subjeot on its opposite face to the pressure in a conduit 52 having its opposite end opening into a part of the furnace where there is pressure. Spring 49 is adjusted so that the furnace pressure is sufiicient to normally hold the valve member 40m in its lower position, Fig. 3, closing communication to the atmosphere and establishing communication from the bellows chamber 35 to the superheater. If the fire goes out and the pressure in the furnace drops, the valve member 4012 rises to its upper position, the pressure in the bellows 35 is evacuated, it moves down, lever 31 is swung over and the effect, as before, is to increase the water supply to meet the sudden drop in the boiler water level.

In these feed water regulator systems, the automatic control of the water regulating valve by the means before described takes care of ordinary fluctuations in water level, and indeed, to some extent satisfies extraordinary demands for water, such as by the production 'of an abnormal pressure differential between the boiler and the steam main. Such systems usually also include a pressure differential valve in the water line ahead of the feed water regulator valve, whose function is to maintain a fairly definite value of feed water pressure over boiler pressure. This pressure differential is usually set aslow as possible so that operating movement of the feed water regulating valve produces only slight changes in the rate of feed from the pressure differential valve. In other words, if the boiler water level drops suddenly, even so much as to produce maximum wide open position of the water regulating valve, the pressure differential regulating valve will be practically unaffected, permitting water to flow to the water regulating valve and thence to the boiler only at the pressure, and consequently at the rate, at which the pressure differential valve is set. The pressure differential valve is always a restriction upon water flow and hence, under an emergency drop in boiler water level, it restricts and delays rise in level of the water in the boiler.

For the purpose of speedily restoring the water level to normal upon an emergency fall, and to dispense with all retarding or restricting effects under such emergency conditions, I provide means sensitive to abnormal fail in water level, but practically unafiected by normal fall therein, for substantially by-passing the pressure diiferential valve, or, in other words, for fully and widely opening the same under the emergency conditions referred to. The particular means shown includes a pressure differential valve sensitive to its own discharge water pressure and to boiler pressure, and arranged to thereby maintain a substantially uniform pressure of the supply to the water regulator valve, and also arranged to subject its moving valve mechanism to another force or forces upon the occurrence of emergency conditions, so as to produce a by-passing eifect and fully open the valve.

The pressure differential valve mechanism shown in Figs. 1, 6 and 8 includes a hollow casing 53 connected to the valve body 4 having a chamber therein connected on its intake side to the water supply pipe 2 and on its outlet side to the water regulating valve 3, so that water flows therethrough in the direction of the arrow B, Fig. 6. In the valve openings in the cross wall of the valve body is a balanced valve member 55 connected to a stem 56 extending through the hollow casing and at its opposite end attached to a movable abutment, such as the expansible bellows 5'7. The chamber within the valve casing is in open communication with the low pressure side of the valve, so that the water pressure beyond the valve is always effective upon the outside of the expansible bellows 57, the effect of said pressure being to tend to move the valve to the left in Fig. 6 or toward closed position. The chamber within the bellows communicates by a pipe 58 with a two-way valve mechanism, generally marked 59, of the same form illustrated in Fig. 3, so that no detailed description thereof is necessary. Said valve mechanism is shiftable to two positions, in one of which the pipe 58 is in communication with a pipeGO communicating by way of a hand valve 61 with any suitable source of boiler pressure, such as the water pipe 19, and in the second position with a pipe 62, communicating with the high pressure side of the differential pressure valve. Valve mechanism 59 includes a diaphragm or abutment effective upon its valve stem and which in this case communicates by way of a pipe 63 with suitable means sensitive to abnormal fluctuations in boiler water level, for controlling the pressure diiferential valve. The means shown for this purpose is a supplemental or additional emergency generator, marked 64,

which includes a pipe loop 65 spanning the boiler water level, as shown in Fig. 1, as well as a finned heat radiating hollow member 66 containing a trapped generating chamber holdingvaporizable liquid, such as water, such trapped chamber being in communication with the pipe 63. This emergency generator is generally similar to the generator 5, although it need not be adjustable. It is set, preferably, on an incline across what may be termed an emergency low water level, represented by the line C, Fig. 1. As shown in the drawings pipe 65 may be fixedly connected, as by welding, to the base pipe 15 and thereby form part of the standard generator unit before referred to. Proper relation between the normal and emergency generators is thereby maintained under all conditions.

The operation is as follows:

Under normal conditions the water level in the boiler is at the line A and the emergency generator loop 65 is filled with water up to that level,

so that in effect none of the liquid in the trapped.

chamber of supplemental generator member 66 is vaporized. Therefore pipe 63 transmits to the diaphragm in the valve mechanism 59 the minimum or low pressure and its valve stands in a position corresponding to the position of the valve member 47, Fig. 3, with the pipe 58 communicating with pipe 60. Consequently, the expansible bellows of the pressure differential valve mechanism is subject on its exterior to the low water pressure of valve 3 and on its interior to boiler pressure. The latter is always less than the former, so that the preponderating water pressure tends to move the valve to the left in Fig. 6,0r toward closed position. The valve 54 may also be subject to the effect of an adjustable member, such as the spring 90 at one end abutting a cbllar 91 on the valve stem, and at its opposite end an abutment 67 threaded for adjustment upon a screw rod 68 passing through a packing 69 to the outside of the casing where it is equipped with means, such as the hex head 70, for rotating it and varying the compression of the spring 90. Spring 90 maybe set so that the balance of pressures, under the normal operating conditions before referred to, provides any desirable constant pressure differential effect across the valve I 3. In other words, the net effect upon the valve stem of the boiler pressure within the bellows 5'7, the water pressure external thereto and on the supply side of valve 3, and the pressure of spring 90, holds the valve member 55 in such a position as to permit only a definite desired water supply to valve 3.

If the water level in the boiler drops abnormally to an emergency position, to or below the emergency water level C, then the liquid in the trapped chamber of the emergency generator is subjected to the effect of a steam zone in the pipe loop 65, with consequent expansion of its vaporizable liquid and the production of an increasing pressure effect upon the diaphragm of valve mechanism 59. The valve member thereof consequently moves over to its second position, closing communication from pipe 58 to. the boiler pressure pipe 60 and opening communication between pipe 58 and the water pressure pipe 62. A new condition, now arises, because the stem of the pressure differential valve is now subjected to the full pressure of the water main on the interior of the bellows 57, to reduced water pressure on the exterior of the expansible bellows, and also to the pressure of spring 90. The new pressure within the bellows 57 is greater preponderating effect which moves the valve 55 to the right in Fig. 6 to fully open position, the effect being to immediately supply to the water regulating valve 3, whatever be its position, the maximum water supply. The water level of the boiler consequently is raised rapidly and as soon as said water level rises above the emergency generator 64 the trapped liquid therein ceases to be affected by a steam zone, but is affected by the water column in the pipe loop 65, which condenses the, vaporizable liquid in the trapped chamber and reduces the pressure transmitted to the diaphragm of valve mechanism 59, so that the valve member thereof returns to its initial position, again connects pipe 58 to the boiler pressure pipe 60, and restores the pressure differential mechanism to its normal operating condition.

Manually operatable by-passing means is also provided, such as the by-pass pipe '77 provided with a hand valve 78 and connecting pipe 58 to the water pressure pipe 62. By manually closing valve 61 and opening valve 78 the same effect is secured as though the valve mechanism 59 had been operated by an increase in pressure in the trapped chamber of the emergency generator.

Some protecting means is desirable for the pressure differential valve mechanism, because sudden operation of its controlling valve mechanism 59 by the emergency generator or by the manual by-passing means will cause sudden application of full water line pressure to the interior of the bellows 57 and slam over the valve to maximum wide open position, sometimes with a rebound or whipping effect producing objectionable surges in the water lines, vibration or the like, or, unusually high water pressure may injure the bellows. I therefore provide graduating means for limiting or controlling the application of high pressure to the bellows, such as the arrangement shown in Fig. 8, where the pressure fiows from pipe 58 to the bellows 5'7 by way of a port or opening 80 through which projects an extension 81 of the valve stem provided with a longitudinally extending graduated metering groove 82 with an increasing restriction 83 near its outer end, and beyond which the extension carries a check valve 84 adapted to cooperate with a seat 85 around the opening 80. During normal operation the parts are in the position shown in Fig. 6, with a fairly uniform portion of the groove 82 forming the opening from pipe 58 to the bellows 57. With ordinary valve movements the extension 81 travels back and forth in its opening without materially affecting the pressure fiow to the bellows. However, upon emergency operation, which might slam over the valve mechanism, the restricted portion 83 of the metering groove enters the opening 80 and more and more retards pressure flow from the pipe 58 to the bellows, to slow up the final portion of the movement of the valve mechanism and avoid the chattering and vibration before referred to. In the final position of the parts the check valve 84 reaches its seat 85 and cuts off all pressure flow from the pipe 58 to the bellows 57, protecting the latter from expansion or extension beyond the safe elastic limit for which it is designed.

What I claim is:

1. A controlling generator for feed water regulating systems, comprising a pipe adapted for connection to the steam and water spaces of a than boiler pressure, so that there is an increased boiler, and a trapped generating chamber member associated in heat conducting relation there with, saidpipe at its lower end including a hollow well member communicating at its upper end with the water space of the boiler, said pipe communicating with said well near to the bottom thereof, and said well being provided with external heat radiating members.

2. In a feed water regulating system, the combination with a controlling generator, comprising a pipe adapted for connection to the steam and water spaces of the boiler, and a trapped generating chamber member associated in heat conducting relation therewith, of a feed water regulating means controlled thereby, said member being adjustable relatively to said pipe.

3. A feed water regulating system, as in claim 2, in which said trapped generating chamber member is adjustable longitudinally of said pipe.

4. A controller for feed water regulating systems, comprising a boiler, a feed water regulator therefor, controlling means for said regulator, said means including a steam and water conducting member communicating with the boiler, and an associated trapped chamber generating member operatively related to said regulator, said members being relatively adjustable to vary the boiler water level, and means sensitive to variations in a function of boiler operation for so adjusting them.

5. A controlling generator for feed water regulating systems, comprising a pipe adapted for connection to the steam and water spaces of the boiler, and a trapped generating chamber member associated in heat conducting relation therewith, said pipe and member being relatively adjustable, and means responsive to variations in a function of boiler operation for so adjusting them..

6. A controlling generator for feed water regulating systems, comprising a pipe adapted for connection to the steam and water spaces of the boiler, and a trapped generating chamber member associated in heat conducting relation therewith, said member being adjustable relatively to the pipe, operating means for moving said member along its path of adjustment, and automatic control means for said operating means.

7. In combination, a boiler, a feed water regulator therefor, a controlling generator including a pipe communicating with the water and steam spaces of the boiler, a trapped generating chamber member adjustable along said pipe to various levels, operating means for said regulator controlled by variations in pressure in the chamber of said member, and means for adjusting said member.

8. In combination, a boiler, a feed water regulator therefor, a controlling generator for said regulator, including a pipe communicating with the water and steam spaces of the boiler, a trapped generating chamber member adjustable along said pipe to various levels, means whereby variations in pressure in the chamber of said member control said regulator, and means sensitive to the pressure drop between the boiler and steam supply for automatically adjusting said member to maintain substantially uniform boiler water level by actuation of said regulator.

9. A combination as in claim 8, including means sensitive to the existence of fire at the boiler for also controlling said member to produce maximum opening of said regulator when the fire ceases. I

10. In combination, a boiler, a feed water regulator therefor, a pressure differential valve sen-' sitive to the pressure drop across the regulator for supplying water thereto, generator control means for said regulator, and control means sensitive to abnormal low water level in the boiler and effective upon said pressure diiferential valve independently of the regulator for automatically opening said pressure differential valve under emergency conditions.

11. In combination, a boiler, a feed water regulator therefor, pressure differential valve mechanism for controlling the supply of water to said regulator, automatic means for controlling said regulator in accordance with variations in water level in the boiler, emergency means for also controlling said regulator to fully open the same upon abnormal demand for steam, and emergency means effective upon abnormal fall in water level for by-passing said pressure differential valve mechanism and supplying unrestricted water flow to said regulator.

12. In combination, a boiler, a feed water regulator therefor, pressure differential valve mechanism ahead of said regulator and tending to maintain a constant pressure drop across the same, automatic control means for said regulator, and supplementary emergency control means for said pressure difierential valve mechanism sensitive to abnormal fall in water level.

13. In combination, a boiler, a feed water regulator therefor, pressure differential valve mechanism ahead of said regulator and tending to maintain a constant pressure drop across the same, generator control means for said regulator and supplementary generator control means for said pressure differential valve mechanism, said first named generator control means being located substantially at normal water level in the boiler and said supplementary generator control means at substantially emergency low water level in the boiler.

14. In combination, a boiler, a feed water regulator therefor, pressure differential valve mechanism ahead of said feed water regulator and tending to maintain a constant pressure drop across the same, and control means sensitive to abnormal drop in water level and directly effective upon said pressure differential valve mechanism independently of said regulator for controlling said pressure differential valve mechanism to increase the pressure drop across the regulator under emergency conditions.

15. In combination, a boiler, a feed water regulator therefor, pressure differential valve mechanism ahead of said regulator and tending to maintain a constant pressure drop across the same, generator control means for said regulator, and supplementary emergency generator control means for said pressure differential valve mechanism, said first namedgenerator control means being located substantially at normal water level in the boiler and said supplementary generator control means being located at substantially emergency low water level in the boiler, said emergency generator control means including a conduit spanning the water level of the boiler, and a trapped generating chambermember associated in heat conducting relation therewith and lying at an emergency low water level.

16. In combination, a boiler, a feed water regulator therefor, pressure differential valve mechanism ahead of the regulator, said pressure differential valve mechanism including a valve member, means subject to varying pressures for automatically adjusting the valve member to maintain substantially uniform pressure at the regulator, and means adapted upon abnormal drop in water level in the boiler for increasing the pressure effective to open said pressure differential valve, to thereby supply undiminished water flow to said regulator in emergency.

17. Controlling means for feed water regulating systems, comprising a boiler, a feed Water regulating device therefor, a generator type regulator for said device adapted to maintain a definite level of water and adjustable to vary such definite level in accordance with the setting of the regulator, and means sensitive to variations in a function of boiler output for adjusting the regulator to vary the water level.

18. Controlling means for feed water regulating systems, comprising a boiler, a feed water controlling device therefor, a generator type regulator for said device adapted to maintain a definite level of water and adjustable to vary such definite level in accordance with the setting of the regulator, and means sensitive to variations in a pressure drop which bears a definite relation to boiler rating for adjusting the regulator to vary the water level.

19. Controlling means for feed water regulating systems, comprising a boiler, a feed water controlling device therefor, a regulator for said device adapted to maintain a definite level of water and variable to change such definite level in accordance with the setting of the regulator, and means sensitive to variations in a function of boiler output for varying the regulator to change the water level.

20. Controlling means for feed water regulating systems, comprising a boiler, a feed water controlling device therefor, a regulator for said device adapted to maintain a definite level of water and adjustable to vary such definite level in accordance with the setting of the regulator, and means sensitive to variations in a pressure drop which bears a definite relation to boiler rating for adjusting the regulator to vary the water level.

- 21. In combination, a boiler, a feed water regulator therefor, a controlling generator for said regulator, including a pipe communicating with the steam and water spaces of the boiler, a trapped generating chamber member associated therewith and adjustable relatively thereto and sensitive to variations in boiler water level for controlling said regulator to maintain substantially constant water level, means sensitive to a function of boiler operation for adjusting said chamber member, and means sensitive to the existence of fire at the boiler. for also adjusting said chamber member.

22. A controlling generator for feed water regu lating systems, comprising a steam and water leg adapted for connection to the steam and water spaces of a boiler, a pipe communicating with the steam and water spaces of said leg, and a trapped generating chamber member associated in heat conducting relation with said pipe and spamiing the water level of the boiler, whereby normal variations of level of water in the boiler produce normally varying heat transfer effects upon said chamber member, said pipe having its lower portion provided with a cold water well having heat radiating means and a capacity at least as great as the portion of said pipe opposite the trapped chamber generating member, said pipe at its upper end including means adapted and effective only upon abnormal rise in boiler water level in said steam and water leg to abnormally raise the water level in said pipe and cause the cooler water from said well to abnormally increase the cooling eflect upon said chamber member to produce an abnormally prompt response thereof.

23. The method of controlling liquid supply to a vapor generating boiler in which it is desired to maintain a predetermined liquid level for all rates of boiler output, which includes, establishing a predetermined fictitious liquid level for the boiler for each predetermined increase or decrease in rate of boiler output, and using said fictitious liquid level to control the liquid supply in a manner to respectively supply more or less liquid to said boiler upon said increase or decrease in rate of output.

24. The method of controlling a steam generating boiler which includes establishing a desirable water level to be maintained in the boiler for all rates of output of the boiler, establishing a fictitious water level a predetermined distance respectively below or above said desirable water level for each predetermined increase or decrease in rate of boiler output, using said fictitious water level to control the feed of water to said boiler in a manner to respectively feed more or less water to said boiler upon said increase or decrease rate of output.

25. The method of controlling a vapor-generator in which it is desired to maintain a predetermined liquid level for all rates of boiler output, which includes establishing a predetermined fictitious liquid level for the generator which is progressively lower with increasing ratings, and then utilizing said fictitious liquid level to progressively increase the rate of liquid feed to the generator commensurate with said increases in ratmg.

26. The method of controlling a vapor-generator in which it is desired to maintain a predetermined liquid level for all rates of generator output, which includes establishing a predetermined fictitious liquid level for the generator for each rate of vapor outflow, and utilizing the fictitious liquid level to maintain rate of liquid infiow in substantial harmony with rate of vapor outflow 27. The method of controlling a vapor-generator in .which it is desired to maintain a predetermined liquid level Ior all rates of generator output, which includes establishing a predetermined fictitious liquid level for the generator for each rate of vapor outflow, utilizing the fictitious liquid level to maintain rate of liquid inflow in substantial harmony with rate of vapor outflow, and causing a departure from such harmony responsive to abnormal furnace conditions.

JOSEPH M. BARRETT.

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