US3194498A - Humidifying system - Google Patents

Description

July 13 1965 G. 1 MINER ETAL 3,194,498

HUMIDIFYING SYSTEM Filed May 17, 196s 2 sheets-sheet 1" ARTHUR MAGSON AT To EY July 13, 1965 G. MINER ETAL HUMIDIFYING SYSTEM 2 Sheets-Sheet 2A Filed May 17, 1965 INVENTORS GEORGE L. MINER ARTHUR MAGSON United States Patent O 3,11%,498 llUl/llDiitiYlli-IG SYSTEM George L. Miner, Warwick, and Arthur Magson, Cumberland, Rl., assignors to Grinnell Corporation, Providence, Rl., .a corporation of Delaware Filed May 17, 1963, Ser. No. 281,203 9 Claims. (Cl. 2216-44) This invention relates to improve-ments in humidifying systems of the kind wherein the moisture is delivered into the atmosphere from atomizer nozzles which are supp-lied by air and water under pressure and which produce a iinely divided water spray. Conventionally, such atomizers are located near the ceiling of an enclosure, :and their spray is line enough to evaporate before the droplets therein can reach objects in the enclosure, for example textile looms in a weave shed. Such machines must be run in an artiiicially high relative humidity, but they would be damaged or would produce inferior textiles if the droplets reached them before evaporating.

More particularly, this :invention relates to improvements in humiditying systems employing atomizers of the k-ind'in which the water and air under pressure are delivered to a mixing chamber in the atomizer `adjacent the atomizer discharge orifice. The signicance of this is that in such atomizers the water pressure in the system must exceed the a-ir pressure as long Ias the water valve in each atomizer is open so that the air will not be forced back into the water system. These water valves :are conventional in pressure atomizers and are essentially spring loaded relief valves which open and admit water to the mixing chamber when the water pressure reache-s a predetermined value. There are no corresponding air valves in these atomizers so that air pressure lcd to the atomizers merely enters the mixing chamber and then escapes through the discharge oriiice Auntil the atomizer water valve opens, whereupon the mixture of :air and water escapes from the orilice.

One feature of the present invention is that it provides a novel arrangement for maintaining the water pressure entering the nozzle mixing chamber at a higher value than the air pressure entering the mixing chamber as long as the atomizer water valves are open.

There are other types of atomizers in use today for which systems of' a substantially different nat-ure are required because they are of the Vacuum type or semipressure type. In both these other types the water is discharged directly from the water system into atmosphere without first being discharged into a mixing chamber inside the atomizer. The yair under pressure is also discharged directly to atmosphere, but closely adjacent to the water discharge and byV this proximity the moving air educes the water stream and breaks it up. In such atomizers there is no danger that the air pressure can enter the water system and hence the air pressure often exceeds the-watel pressure.

Pressure type atomizers of the kind used with the present invention have certain advantages over the vacuum or semi-pressure" atomizers. @ne such advantage is that they use appreciably less air for 4a given amount of water discharged, but wherethese pressure type atomizers have been used in the past diiliculties have been encountered in satisfactorily relating the water and `air pressures to keep the water pressure higher when the atomizer water valves are open. these earlier syste-ms in relating the water and :air pressuers to maintain the optimum air-to-water ratio during the turning on, running, and shutting off of the atomizers.

With respect to this above-mentioned air-to-water ratio, the best quality waterspray is achieved when the ratio of the cubic feet of lair per hour to the pounds of water per hour delivered is in the neighborhood of 8: 1. Values for Further difficulties have been encountered in 3,194,49 Patented July i3, 1955 ICC this ratio as low as 4:1 and as high as 12:1 can-be tolerated, but when the ratio drops below 4:1 the spray becomes too coarse to evaporate quick-ly, `and droplets tall on the surfaces in the enclosure being humidified. When the ratio exceeds 12:1 the spray quality does not suffer (nor is it significantly better than at 8:1) but the amount of air used is so great that there is `a wasteful ineiiciency. Another feature of the present invention is that it provides 'a novel arrangement for .so relating the water and air pressures that the `most advantageous air-to-water ratios are maintained, and this result is achieved with inexpensive equipment during the critical turning on and shutting off periods as well as during steady on conditions.

One or" the characteristics of these systems is that they operate intermittently. Normally, the atomizers are turned oit, but when the humidity detector senses that the relative humidity in the enclosure has fallen below the desired level it activates the system to turn on the atomizers. Between the time when the atomizers begin to discharge and the time when the atomizers are running at full capacity the spray discharge builds up from zero to full rate. This period of time is short, being in the order of a second or so, but even in this time it is important that the `air-to-water ratio be within the desired limits yand that the air pressure does not exceed the water pressure while the atomizer water valves are open. Similarly, when the humidity detector senses that the relative humidity in the enclosure has been restored to the desired level by the system operation it cle-activates the system to turn olf the atomizers, and again there is a short period of turning-off time during which the relative pressures of air and water must be controlled to assure that the air-t-o-water ratio is maintained and that the air pressure does not exceed the water pressure until the atomizer water Valves are closed. The present invention provides a simple and inexpensive system for controlling these conditions during these initiating, running, and terminating periods.

In general, one system according to the present invention has a first valve which is located in the main air line from the air supply to the atomizers and which valve iis opened by the humidity detect-or. A restriction lassociated with this iirst valve provides a pressure drop between the upstream and downstream sides. When the air pressure on the downstream side reaches a certain value it operates a second valve which is in a sepa-rate air line conducting air pressure from the air supply to the surface of water in a closed water supply tank. This air pressure on the water surface builds up the water pressure to the atomizers which receive water from the tank. The certain air pressure on the downstream side of the first valve and the other air pressure on the tank .are related by the restric- .tion so that the water pressure .at the atomizers is higher than the air pressure at the atomizers when the water valves in the atomizers are open.

In general the proper air-to-water ratio is maintained by proper selection of the restriction which relates the air and water pressures, since the water pressure is derived from or controlled by the same pressurized air supply.

At the shut olf, the system maintains the atomizer water pressure higher than the atomizer air pressure (at least until the atomizer water valve closes) by retardinggthe drop in air pressure in the water tank to make sure that the water pressure remains above the air pressure at the atomizer. The drop in air pressure in the tank results from the opening of a first exhaust port when the first valve is closed by the humidity detector. When the water pressure at the atomizer drops low enough to shut the water valve therein the air pressure on the downstream side of the iirst valve is low enough to rapidly exhaust the air pressure on the-water tank through a second exhaust port. The drop in air pressure on the downstream side of the first valve results from the air escaping from the atomizers. During this shut-down, the proper air-towater ratio is initially maintained by regulating the rate at which air escapes from the water tank via the rst exhaust port relative to the rate at which air escapes from the atomizers and is later maintained by regulating the rate at which air pressure escapes from the water tank via the second exhaust port.

In this system being generally described some fixed pressure differential can be achieved by locating the water tank a certain distance above the level of the atomizers (which are usually all at about the saine level). yThis head cannot be so'great that it opens the Water valves in the atomizers, but a signicant amount of head makes possible the use of a larger restriction associated with the first valve.

It is an object of the present invention to provide an improved humidifying system for pressure-type atomizers in which the water pressure is maintained above the air pressure during discharge in a novel way and in which the air-to-water ratio is controlled in a novel way.

Another object of the invention is to provide a system in which the water pressure is at least in part derived from air imposed on aclosed Water tank, this air pressure coming from the same source which supplies air to the nozzles.

Another object is to provide a system of the kind described in which a restriction in the air supply line assists in maintaining the air pressure in the water tank at a higher level than the air pressure at the nozzles.

Another object is to provide a system of the kind described in which the actuation of a humidity detector admits supply air pressure to the actuator of a normally closed valve which when open admits air pressure to the nozzles from such supply.

Another object is to provide a system of the kind described in which nozzle air pressure of a certain amount closes a relativelylarge water tank air exhaust, whereby the air pressure in the tank quickly reaches full supply pressure.

Another object is the adjustment of these various corn-V ponents so that when the water pressure at the nozzles reaches a predetermined value it has already exceeded the l' air pressure in the nozzles.

Another object is to provide a relatively small water tank air exhaust which is opened when the new humidity condition causes the supply of air pressure to the tank to be stopped.

Another object is to provide an accelerator which causes the valve controlling air to the atomizers to close quickly when the humidity detector indicates the proper relative humidity has been achieved.

Another object is to provide a system of the kind described which is simple in construction, reliable in performance, easily installed and adjusted and convenient to maintain and repair.

Other objects will appear hereinafter.

The best mode in which it has been contemplated applying the principles of the present invention are shown in the accompanying drawings, but these are to be deemed primarily illustrative for it is intended that the patent shall cover by suitable expression in the claims whatever of patentable novelty exists in the invention disclosed.

In the drawings:

FIGURE 1 is a side-elevation View of one embodiment of the present invention with certain components shown in cross-section;

FIGURE 2 is an enlarged cross-sectioned side-elevation View of the discharge nozzle used in the system of FIGS. 1 and 4;

FIGURE 3 is an enlarged cross-sectioned side-elevation view of a valve controlling the large exhaust port for the water tank;

Y FIGURE 4 is a View like FIG. l, but showing another embodiment of the invention;

haust for the water tank, and

FIGURE 6 is a fragmentary cross-sectioned side-elevation View of the orifice plate used in the system of FIG. 5.

Referring now to the embodiment of FIG. 1, the discharge nozzle 10 is one of many which are usedrin a system of this kind but'which are not shown here because one such nozzle is suflicient to describe the operation of all. Air under pressure is brought to the nozzle by pipe 12 which connects to air manifold pipe 1d. Water under pressure is brought to the nozzle l@ by pipe 16 which connects to water manifold 1S.

FIGURE 2 shows how nozzle 1t) is constructed. Water under pressure entering chamber 2t) Vfrom pipe 16 acts on diaphragm 22 which is normally held in the position shown by compressed spring 24. The amount of spring compression is adjusted by nut 24 so that diaphragm 22 is not moved to the left by water pressure in chamber 2@ until this pressure reaches a predetermined value, for example, 28 p.s.i. in a typical system. Above 28 p.s.i. the diaphragm movement moves cylinder 25 which is attached to the diaphragm at one end and which has a soft valve seating member 28 at the other end. This movement opens the valve aperture 3d which was closed by the seating member 28 and permits water from chamber 2@ and pipe 16 to pass along passage 32 and through orifice 34 into intermediate chamber 36. This chamber 36 is also supplied with air under pressure which reaches, it from pipe l2 via passages 38 and dit. Air and water are fdischarged from the intermediate chamber to atmosphere through the orifice 42.

From the foregoing it will be understood why pressure atomizers of this kind are subject to air entering the water system if the water valve 2.8-30 is open and if the air pressure in the -intermediate chamber 36 exceeds the water pressure. In such case air can Venter orifice 34 and pass along passage 32, through valve 28-30 (assumed to be open) and thus reach pipe I6. The disadvantage of air in the water system is that it forms an air cushion, and subsequent decreases in water manifold pressure during the'atomizer shut-oit result in large movements of Water back into the water supply because of the expansion of the compressed air trapped in the water system. Such movements of large amounts of water may take so much time that the water pressure drops slowly at a time when more rapid pressure drops are desired. Turning now to the operation of the rest of the system :of FIG. 1, 44 designates generally a humidity detector of conventional design the construction of which is wellknown to persons skilled in this art. It will suffice to explain that when the relative humidity in the enclosure served by the syst-em Yfall below the desired level an electric signal is generated in leads 46 which connect to a solenoid operated three-way valve 48 in pipe 5t). This signal opens this valve and allows air pressure from a main air supply pipe 52 to enter the actuator 54 via pipe 56 and also to enter pipe 58 through restriction 60.

The electric switch of the humidity detector 44 is operated by fluctuations in air pressure brought to the detector via pipes 62 and 64. More particularly, a humidity 'sensitive element in the detector varies the amount of opening of a bleed orifice in a first chamber supplied by pipe 62. The orifice opening is also effected by pressure in a second feed back chamber fed by pipe 64. The pressure fluctuations in the first chamber actuate the electric switch. The AMCO K-Z Control referred to at the end of the specification has such a construction.

Air pressure admitted to actuator 54 opens the valve 66 against the force of a spring 68 therein and permits supply air pressure in line 52. to enter the air manifold 14. A metering device in the form of an orifice plate 7d provides a pressure drop from the supply pressure to a lower value for the manifold 14. The pipe 52, plate 7d and valve 66 of FIG. 1 are `the same in construction and operation as the pipe 148, plate 156 and valve 122 of FIG. 6.

AirV pressure admitted to pipe 58 passes through water trap 72A and is exhausted through port 74 in normally open auxiliary valve 76.

This valve 76 is held open by a spring 78 (see FIG. 3) which holds seating member 80V away from seat 32 and through cylinder 8 4 holds diaphragm 86 to the left against the force of much weaker spring S8. When air pressure in air manifold 14 reaches a certain level, for example about p.s.i., it acts through pipe 9i) on diaphragm 86 and overcomes the spring 78, thereby closing the seating member 80 on its seat 82. Thereafter air in pipe 92- cannot exhaust through port 74, and as a result pressure in watertank 94 builds upt This tank is located with the water level therein about twofeet above the level of the atomizer heads so that there is always a slight water pressure at these heads, even when there is no air pressure in the water tank 94. This head is not suiiicient alone, however, to open the Water valves 28-30 in the heads.

Water is supplied to the tank through a water supply line 96 and a oat valve 98. The pressure inline 96 contributes to the pressure in the tank in the sense that the pressure in line 96 must be at least as great as the pressure in the tank 94, and operation of the float valve 98 in the tank effectively controls the introduction of water under pressure to the tank. A sight glass 100 is furnished so that the water level in the tank can be seen.

The water pressure thus derived builds up more rapidly in pipe 18 than the air pressure in air manifold 14 because of the fact that the orifice plate 70 produces a lower pressure in 14 than in 52, and even though a restriction 60 is between 52 and tank 94 the air volume of piping 50, 58, 92 and tank 94is so much smaller than the air volume of manifold 14 that the pressure in tank 94 rises faster than the pressure in manifold 14, and exceeds the air pressure by the time the water pressure at the atomizer reaches 28 p.s.i. Another reason why the water pressure rises so much faster than the air pressure is that the water valves in each atomizer `are closed, whereas the air reaching the atomizers can escape. This slows down the increase in air pressure at the atomizer.

Having achieved 28 p.s.i. the water pressure at the atomizer opens thewater valves in the atomizers and the atomizers -begin to discharge. In this initiall period the water andl air pressures continue to increase to their full operating values which in a typical system of the kind shown in FIG. 1 are approximately 32.5 p.s.i. and 30 p.s.i., respectively.

When the humidity detector 44 determines that the relative humidity has been restored to the desired level by the atomizer discharge it closes valve 4S which connects pipe 50 to an exhaust port 48a. As a result the air pressurein actuator 54 drops rapidly below the point where itovercomes spring 68, and valve 66 closes, shutting off air, from the supply to manifold 14. This closing of valve 66 is accelerated in the embodiment of the drawings by the provision of an air chamber 102 under the diaphragm 104 in the actuator 54 and by a connection 106 from the air manifold 14 to the chamber 132. Since the pressure in air manifold 14 is quite high before valve 66 has closed some of this pressure in chamber 1112 plus spring 68 causes the valve 66 to close much more quickly than it would with the spring alone when air is exhausted from upper chamber 108 of the actuator 54. A pressure reducing device 110 is located in line 106 to provide a pressure in chamber 102 which is less than the air manifold pressure.

As in the case of turning the atomizers on, it is desired during the turning off to maintain the water pressure at the atomizer higher than the air pressure there at least until` the atomizer water valves close. This result is achieved in the embodiment of FIG. l because the exhaust port 48a provides the only escape for air pressure on the tank 94 until valve '74k opens, and restriction 60 controls this exhausting. Valve 74 does not open until air pressure in manifold 14 drops to about 20 p.s.i. This latter drop results from the air in the manifold 14`escaping from each` nozzle, and restriction 60 is set so that water pressure at atomizers does not fall below manifold (14) pressure at least until water pressure at atomizers is below 28 p.s.i. at which value water valves in atomizers close. Once these atomizer water valves all close both the air and wat-er pressures can. be lowered quickly in a convenient fashion, for example by having valve 76 open at 20 p.s.i. in manifold 14 and provide a larger (than restriction 611) exhaustl for the air pressurein the tank. Pressure in manifold 14 will continue to drop by the eX- hausting of air through. nozzle orifices 42.

Pressure guages 112 and114 on the water line 18 and air manif-old 14 respectively assist in the adjustment of the system to achieve the relative pressure values at the proper times as described.

FIGURE 4 shows another embodiment of the invention which is like that of FIG, l in all major respects, but in which the tank 116 initially receives airpressure from air manifold 118 and later exhausts to manifold 118 when valve 1,20 is closed. More particularly, opening valve 1211 opens valve 122, and air pressure begins to build up in air manifold 11S. This air pressure also begins to build up in tank 116 because auxiliary valve 123 is in the position shown in FIG. 5 until the air pressure in manifold 113 and line 124 reaches a certain value, for example 20 p.s.i. In position of valve 123 which is shown the air pressure from pipe 124 passesfr-om chamber 126 along passage 12d, through valve aperture 139, through passage 132 and out along pipe 134. The passage 128 is suiciently restrictive so that when the pressure in pipe 124 reaches a predetermined value air cannot escape along the passage 12S fast enough and diaphragm 13:6y is moved downwardly against the force of spring 138 to close the soft seating member 140cm the aperture 130. Simultaneously, this movement of the diaphragm lowers seating member 142 away from aperture 144-to open the same and connect pipe 146 with pipe 134.

Thus at the predetermined pressure in manifold 118 air pressure from the supply 143 is conducted to tank 116 via pipe 151i, valve 12d, pipe 152, restriction 154, pipe 146, valve 123 and pipe 134. This predetermined pressure and the setting of valve 154 are selected so that when valve 123 operates as above described the air pressure in pipe 146 already exceeds the air pressure in the manifold 113 or at least exceeds this manifold pressure before the manifold pressure reaches the pressure of operation of the atomizer water valves.

Upon the closing of valve 12? to achieve a turning off of the atomizers 153, valve 122 closes and the manifold air pressure begins to drop. However, until this manifold air pressure reaches theA operational value of valve 123 air in the tank 116 has to exhaust through ports 12661 via restriction valve 154 whichis set so that, even while dropping, the pressure in tank 116 is held aboveL the air manifold pressure at least until the water pressure at the nozzles is below the value at which the water valves therein close. Water reaches the nozzles 153 through a pipe 1611, water manifold pipe 162, and connecting pipes '164.

After the air pressure in manifold 118 drops to the predetermined value at which valve 123 operates, pipe 134 is again connected to pipe 124 and thereafter further venting of tank 116 is into the 'air manifold. In view o-f this it is preferred that the restriction valve 154 be set so that the pressure in 146 is somewhat higher than the pressure in 124 when the latter has dropped to the predetermined value.

One feature of the arrangement of FIG. 4 as thus described is that if during removalof the airV pressure from tank 116 the air trapped in the water system (for example, at high peints along with manifold 162) expands and drives water back along pipe134it might getinto air manifold 118 or air pipe 146. To prevent this the water trap 166 is used. In FIG. 1 such water can escape through exhaust port 74. Y

The humidity detector 168 in FIG. 4 is in all respects the same as the one shown in FIG. l.

It will be understood that although only one atomizer head 1t), 153 is shown in FIGS. 1 and 4, respectively, there would be many such heads in an actual system each connected to the water and air pipes inthe same manner as those shown. v

From the foregoing descriptions of the operations of the embodiments shown a person skilled in this art would be able to select components and adjust them without vexperimentation to obtain the operations described. However, as an aid to readers the components shown in FIG. 1 may be as follows: Pipe 52-1 inch; pipe 14-1 inch and reducing along its length; pipes Si), 56, 5S, 92, 9i), 166, 64, 62., 16, i12-1A inch; pipes 96, 18-1/2 inch; humidity detector 44AMCO K-Z Control manufactured by American Moistening Company of Providence, Rhode Island; solenoid valve Ltid-ASCO Three- Way Solenoid Valve, 1A inch, made by Automatic Switch Co. of Floram Park, New Jersey; valve 66-AMCO Two-Way Air Valve, Model C, 1% inches, manufactured by American Moistening Company of Providence, Rhode Island; orifice plate 70-% inch; restriction 60-1/16 inch aperture adjustable; valve 76-AMCO Monitor Valve, 1/8 inch; atomizer lil-AMCD Aeromiser, 1960 style; water `supply pressure-40-45 p.s.i.; air pressure supply- 33 p.s.1.

What we claim is:

1. In combination with an atomizer nozzle having means for receiving a first fiuid in gaseous state at a first pressure and a second fluid in liquid state at a second pressure which is higher than that of said first pressure, for mixing said gas and liquid together in said nozzle, and for discharging said uids therefrom as a iinelydivided mist or spray, apparatus for controlling and correlating the pressures of said fluids in said nozzle, said apparatus comprising:

(A) a source of said gas under pressure,

i (B) a source of said liquid,

(C) first and second conduit means connecting said gas and liquid sources respectively to said atomizer nozzle receiving means,

(D) third conduit means connecting said gas source to said liquid source,

(E) fiow control means, adapted to be activated by a humidity responsive means, for controlling the admission of said gas from said gas pressure source into said first and third conduit means,

(F) auxiliary valve means in said third conduit means, operable in response to a predetermined value of pressure of said gas in said iirst conduit means for controlling the iiow of said gas in said third conduit means to said liquid source,

(G) fiow restricting means between said gas pressure source and said first conduit for causing said first iiuid to be delivered to said nozzles first -iiuid receiving means at said first pressure and for establishing a pressure differential between said gas pressures in said first and third conduit means, and

(H) flow restricting means in said third conduit means for controlling the rate of fiow of said gas therethrough,

whereby gas upon being admitted into said first and third conduit means by said flow control means in response to a moisture requirement in the atmosphere controlled by said apparatus, ilows through said first conduit means to said atomizer nozzle gas receiving means, and coincident therewith, ows through said third conduit means to said auxiliary valve means by which, upon the attainmentdof said predetermined pressure in said first conduit means, said gas is directed onto said liquid source to pressurize the same and cause said liquid to be delivered through .8 y said second conduit means to said atomizer nozzle liquid receiving means at said second pressure. f f

2. In combination with an atomizer nozzle having a chamber for mixing a first iiuid in gaseous state with a second fluid in liquid state, having means fork receiving said gas at a iirst pressure, having separate means for Vreceiving said liquid at a second pressure which is higher than said first pressure, and having means for discharging said tluids from said mixing chmber as a iinely divided mist or spray, apparatus forcontrolling and correlating the pressures of said iiuids'in said nozzle, said apparatus comprising:

(A) a source of said gas` under pressure,

(B) a source of said liquid,

(C) first and second conduit meansV connecting said gas and liquid sources respectively to said atomizer nozzle receiving means,

(D) third conduit Ameans connecting said gas Source to said liquid source,

(E) flow control means, adapted to be activiated by a humidity responsive means, for controlling the admission of said gas from said gas pressure source into said first and third conduit means,

(F) auxilliary valve means' in said conduit means, operable in response to a predetermined value of pressure of said gas Vin said first conduit means yfor controlling the flow of said gas in said third conduit means to said liquid source,

(G) fiow metering means between said gas pressure source and said first conduit means for reducing the pressure in said iirst conduit means substantially below the pressure of said gas pressure source, for causing said gas to be delivered to said gas receiving means at said first pressure and forv establishing a pressure differential between said gas pressures in said iirst and third conduit means, respectively', and

(H) adjustable flow Vmetering means in said third conduit means for controllingwtherate of flow of said gas therethrough in either direction,

whereby gas, upon being admitted into said first and third conduit means by said tlow control means in response to a moisture requirement inV the atmosphere controlled lby said apparatus, fiows at a reduced pressure through -said first conduit means to said atomizer. nozzle gas receiving means, and coincident therewith flows extending from said third conduit to said auxiliary valve means', at which, upon the attainment of said predetermined pressure in said first conduit means, said gas is admitted into said liquid source by said auxiliary valve means, thereby pressurizing said liquid source and causing said liquid to be deliveredV through saidV second conduit means to said atomizer nozzle liquid receiving means at said second pressure. Y

3. In combination with an atomizer nozzle having a chamber for mixing a iirst fluid in gaseous state with a second fluid in liquid state, having means for receiving said gas at a first pressure, having separate means for receiving said liquid at a second pressure which'is higher than said rst pressure, and having means for discharging said uids from said mixing chamber as a finely divided mist or spray, apparatus for controlling and correlating the pressures of said fluids in said nozzle, said apparatus comprising: Y Y

(A) a source of said gas under pressure,

(B) a source of said liquid, Y

(C) first and second conduit means connecting `said gas and liquid sources respectively to said atomizer nozzle receiving means, p

(D) third conduit means connecting said gas source to said liquid source, 1

(E) iiow control means, adapted toy be activated by a Vhumidity responsive means, for controlling the admission of said gas fromsaid gas pressure source into said first and third conduit means, said flow control means comprising: j Y

( 1) a control valve in said first conduit means,

(2) pilot valve in said third conduit means, and

(3) humidity sensing means for sensing said fluctuations in relative humidity in said atmosphere and for controlling the operation of said concontrol valve and pilot valve means in response to said fluctuations,

(F) auxiliary valve means in said third conduit means, operable in response to a predetermined value of pressure of said gas in said iirst conduit means, for controlling the flow of said gas in said third conduit means to said liquid source,

(G) an orifice between said gas pressure source and said first conduit means for reducing the pressure in said rst conduit means from the gas source pressure to said first pressure, and for establishing a pressure differential between said gas and liquid pressures in said first and second conduit means respectively, and

(H) adjustable flow metering means in said third conduit means for controlling the rate of flow of said gas therethrough in either direction,

whereby gas, upon being admitted from said gas pressure source into said first and third conduit means by said control valve and said pilot valve means, respectively, in response to actuation of said humidity sensing means, ilows through said rst conduit means and arrives at said atom-1 izer nozzle ga-s receiving means at said first pressure, and coincident therewith, iiows through said third conduit means to said auxiliary valve means, where, upon the attainment of a minimum pressure in said rst conduit means, it is admitted to said liquid source by said auxiliary valve means thereby pressurizing said liquid source and causing said liquid to be delivered through said second conduit means to said atomizer nozzle liquid receiving means at said second pressure.

4. In combination with an atomizer nozzle having a chamber for mixing a first fluid in gaseous state with a second fluid in liquid state, having means for receiving said gas at a rst pressure, having means for receiving said liquid at a second pressure which is higher than said rst pressure, and having mean for discharging said fluids from said mixing chamber as a finely divided mist or spray, apparatus for controlling and correlating the pressures of said gas and liquid in said nozzle, said apparatus comprising:

(A) a source of said gas under pressure,

(B) a source of said liquid comprising a closed container partially lled with said liquid,

(C) iirst and second conduit means connecting said gas and liquid sources respectively to said atomizer nozzle receiving means,

(D) third conduit means connecting said gas source to said container,

(E) ow control means, adapted to be activated by a humidity responsive means, for controlling the ad mission of said gas into said first and third conduit means, said ilow control means comprising:

(1) a control valve iuV said first conduit means having gas openated actuator which is connected to said third conduit means, which operates in response to a predetermined gas pressure in said third conduit means to open said control valve, and which operates in response to gas pressures below said predetermined pressure to close said control valve,

(2) pilot valve means in said third conduit means for admitting said gas from said source into said third conduit means when said pilot valve means is in one position of movement and for blocking said admission and venting said third conduit means downstream from said pilot valve means when Said pilot valve means is in another position of movement, and

(3) humidity sensing means for sensing said iluctuations in relative humidity in said atmosphere and for controlling the position of movement of said pilot valve means in response thereto,

(F) auxiliary valve means in said third conduit means between said liquid container and said control valve actuator connection and operable in response to a predetermined gas pressure in said first conduit means downstream side of said control valve, for controlling the admission of gas pressure to said liquid container,

(G) means for establishing a pressure diferentia] between said gas and liquid pressures in said first and second conduit means respectively, and

(H) adjustable low metering means in said third conduit means between said auxiliary valve means and said control valve actuator connection for controlling the rate of flow of said gas therethrough in either direction,

whereby gas pressure from said gas pressure source, upon being admitted into said third conduit means by said pilot valve means in response to actuation of said humidity sensing means and subsequently into said first conduit means by said control valve in response to a predetermined value of pressure of said gas in said third conduit means, iows through said first conduit means to said atomizer nozzle gas receiving means, and coincident therewith, flows through said third conduit means at a controlled rate to said auxiliary valve means where, upon the attainment of a minimum pressure is said first conduit means, said gas is admitted to said liquid container by said auxiliary valve means, thereby pressurizing said liquid container and causing said liquid to be delivered through said second conduit means to said atomizer nozzle liquid receiving means at said second pressure.

5. The combination as recited in claim 4 wherein said liquid container comprises:

(A) a sealed tank containing a quantity of liquid therein and having:

(l) a gas inlet to which said third con-duit means is connected, and

(2) a liquid outlet to which said second conduit means is connected.

6. The combination as recited in claim 5 wherein said means for establishing said pressure diiferential between said gas and liquid pressures comprises means for so 1ocating said t-ank relative to said atomizer that the liquid level in the tank is a predetermined distance above the level of said atomizer.

7. The combination as recited in claim 5 wherein said means for establishing said pressure ditierential between said gas and liquid pressure comprises a restriction in said first conduit means for reducing the pressure of said gas therein from the gas source pressure, whereby said first pressure has a value -less than the pressure of said gas at said gas source.

S. The combination as recited in claim 4 wherein said control valve actuator has a piston-like member separating two actuator pressure chambers and is provided With means for accelerating the rate of closing of said control valve.

9. The combination as recited in claim 8 wherein said means for accelerating comprises a conduit connecting one of said actuator pressure chambers to said first con duit means at a point downstream of said control valve.

References Cited by the Examiner UNITED STATES PATENTS 1,270,159 6/18 Hodge 236-44 1,585,536 5/26 DArcy 236-44 EDWARD l. MICHAEL, Primary Examiner.

ALDEN D. STEWART, Examiner.

Claims (1)

1. IN COMBINATION WITH AN ATOMIZER NOZZLE HAVING MEANS FOR RECEIVING A FIRST FLUID IN GASEOUS STATE AT A FIRST PRESSURE AND A SECOND FLUID IN LIQUD STATE AT A SECOND PRESSURE WHICH IS HIGHER THAN THAT OF SAID FIRST PRESSURE, FOR MIXING SAID GAS AND LIQUID TOGETHER IN SAID NOZZLE, AND FOR DISCHARGING SAID FLUIDS THEREFROM AS A FINELY DIVIDED MIST OR SPRAY, APPARATUS FOR CONTROLLING AND CORRELATING THE PRESSURE OF SAID FLUIDS IN SAID NOZZLE, SAID APPARTUS COMPRISING: (A) A SOURCE OF SAID GAS UNDER PRESSURE, (B) A SOURCE OF SAID LIQUID, (C) FIRST AND SECOND CONDUIT MESN CONNECTING SAID GAS AND LIQUID SOURCES RESPECTIVELY TO SAID ATOMIZER NOZZLE RECEIVING MEANS, (D) THIRD CONDUIT MEANS CONNECTING SAID GAS SOURCE TO SAID LIQUID SOURCE, (E) FLOW CONTROL MEANS, ADAPTED TO BE ACTIVATED BY A HUMIDITY RESPONSIVE MEANS, FOR CONTROLLING THE ADMISSION OF SAID GAS FROM SAID GAS PRESSURE SOURCE INTO SAID FIRST AND THIRD CONDUIT MEANS, (F) AUXILIARY VALVE MEANS IN SAID THIRD CONDUIT MEANS, OPERABLE IN RESPONSE TO A PREDETERMINED VALUE OF PRESSURE OF SAID GAS IN SAID FIRST CONDUIT MEANS FOR CONTROLLING THE FLOW OF SAID GAS IN SAID THIRD CONDUIT MEANS TO SAID LIQUID SOURCE,

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