US1587172A - Liquid-level-controlling device - Google Patents

Description

June 1 1926.

F. 'W. MULLER LIQUID LEVEL CONTROLLING DEVICE Filed Dec, 15. 1923 v ATTORNEY Patented June 1, 1926.

FREDERICK W. M'ULLER, OF I'IOBOKEN, NEW JERSEY.

LIQUID-LEVEL-CONTROLLING DEVICE.

' Application filed December 15, 1923. Serial No. 680,929.

My invention relates generally to the automatic control of the level of a body of liquid by the maintenance of the same between predetermined narrow limits and is more specifically designed to so control the level of a body of liquid in a closed tank, under pressure from a superimposed body of gas, which liquid is being forced into said tank from a source of supply under pressure. The most commonly occurring form of apparatus to which my said invention is applied is a standard type of automatic bottle filling apparatus usually employed for handling carbonated liquids such as beer or mineral waters, ginger ale, etc.

In such bottle filling apparatus the carbonated liquid is fed to a closed tank under pressure and is maintained under pressure therein by a superimposed body of gas exert ing what is known in the art as counterpressure thereon. This counterprcssure is initially established in said tank by introducing a supply of compressed air or carbonic acid gas when the apparatus is put in operation and this body of gas is subsequently increased by air taken from the bottles being filled, and, to a certain extent, by gas escaping from the carbonated liquid,

' though this liberation of gas from the liquid should be kept down to a minimum in good practice. The excess gases so accumulating are released from time to time by some suitable counter pressure control apparatus such as disclosed in my pending application Serial No. 674,539 filed Nov. 13th, 1923, or by an ordinary safety valve. For simplicitys sake no such apparatus is illustrated or described herein, it constituting no part of my present invention. Any fall of'such count-erpressure below the predetermined minimum, due to leakage or other cause, is counteracted, by admission of a fresh supply of gas from the source of initial supply. In suchbottle filling apparatus it is important that the level of the liquid in the tank be maintained approximately at a constant level as the rapidity with which said liquid iiows into the bottles is determined by the hydrostatic head thereof, and even operation of the device therefore requires that said head of liquid be always uniform and constant. The best form of apparatus, at present known to me, embodying my present invention, is illustrated in the accompanying sheet of drawings in which:

Fig. 1 is a side elevation of a form of hottle filling apparatus with my present invention applied thereto, parts being broken away and others shown in section,

Fig. 1'' is an enlarged detail side elevation with parts broken away, showing more clearly the rotatable joints in the pressure fluid connections.

Fig. 2 is an enlarged detail sectional view of the liquid supply controlling valve, and

Fig. 3 is a similar view of t 1e gas pressure cont-rolling valve for operating said liquid supply valve.

Throughout the drawings like reference characters indicate like parts. A, represents general y a standard type of bottle fillin apparatus having the tank 1, partly filled with the gas charged liquid, supported by frame 49, which frame also supports a revoluble spider 2, operated by worm gear 3, carrying vertically reciprocating bottle supports or stirrups 40, raised and lowered automatically by compressed air motor devices 41, so that each bottle 36, is in turn lifted and connected to the interior oftank 1, in order that liquid may flow into and fill the bottle. Compressed air is supplied to the motor devices 41 by piping 4, controlled by hand valve 5, the pressure being indicated by gauge 6. v

7 is a conduit usually of about an inch diameter controlled by a valve apparatus generally represented by B supplying the carbonated liquid under pressure to the liquid containing zone of tank 1. According to my invention the quantity of liquid delivered is kept down to the requirements of consumption by automatic control of a valve in casing 8, said valve being so constructed and operated that there is practically no constriction of the flow of liquid when it is opened, and its opening and c osing are quickly performed so that there is also no wire drawing of the liquid at these stages of its operation.

The carbonic acid or other gas for counterpressure is initially supplied to tank 1 through pipes 1a and 12, controlled by hand operated shut-off valve 15, the degree of such counterpressure existing in the tank at all times being indicated by gauge 17. A standard 18 supports pipes 4:, 12 and 1a, which, as well as pipe 11, which is connected to the stationary valve B, are immovable and therefore must have some kind of rotary joint connection with revolving tank 1. One possible arrangement of piping for this pur pose is diao'ranunatically illustrated in Fig. 1, where 34 is a short, vertical tubular member connected at its top to pipe 4:, and 38 is an outer tubular member concentric with 37 and connected at one side to pipe 11. The annular space between 37 and 38,fron1 which pipe 11 leads, is closed at its top. but at its lower portion opens into a similar annular space between inner tubular member 3'? and the upper portion of standpipe 39, which standpipe is set in a central opening in tank cover 1. A gastight connection between member and the upper end of st'indpipe 39 is formed by the rotary stalling box 38. Pipe 42 leads from the top of: valve (1 to the annular space between 3?, 38 and the upper part of The lower portion of 39 reduced in diameter sufiiciently to form a ro tary gas-tight joint 37" with the lower end of 37. Pipe 12 passes through the side walls of the upper portions of 3'? and and then downwardly through the lower, open end of 87 into the lower portion of standpipe 39 where it' is flanged outwardly to form a rotary, gastight joint 12 with the reduced lower portion of Pipe 9 leads -from the side of valve Q to the said reduced lower portion of 39 and connects with the annular space between pipe 12 and said lower portion of 39 at a point between joints 37 and 12. Evidently standpipe 39 and pipes 9 and 12 will rotate with tank 1 about tubular members 38 and 37 and pipe 12, while 1naintaining gas-tight connections with them. onsequently the counter pressure from pipe 12 is freely admitted at all times to the interior of tank 1 while compressed air from pipe t may pass through tubular member 37 and the medial portion of standpipe 39 to pipe 9, from which it branches through at to the stirrup actuating apparatus L1 and through valve l (when that valve is open) to pipe 4-2, and thence through the annular space about 37 to pipe 11 and valve B.

A crossover connection between pipe systoms 4- and 12 is controlled by valve .18. Normally this valve is closed, but it' the aid of the compressed air used to operate the stirrups 4h), is required to supplement a falling countenpressure ot' the carbonic acid gas, the valve 18. is temporarily opened.

Liquid under pressure enters casing); 8 of valve apparatus B through pipe 19 having the dtw'nwardly turned discharge end 20 which may be closed by the pulling upward of plate valve 21, carried by strap supported from flexible diaphragm 23, which extends across the upper portion of easing 8. The pressure of liquid in the lower and main portion of easing 8 would, if unopposed. liitt diaphragm 23 and hold valve 21 closed, this liquid pressure equalling the back pressure from tank 1, when valve 21 is closed, and the feeding pressure in supply pipe it) when the valve is open. To open said valve it is therefore necessary to create. an opposing pressure in the closed chamber in the upper portion of easing 8 above diaphragm 23, sutlicient to overcome the liquid pressure below said diaphragm.

According to my present invention this opposing valve operatin pressure is supplied by a body of gas confined in said upper chamber above the diaphragm and connected through pipe 11 to some source of substantially uniform air or gas or other fluid pressure which is normally high enough to hold valve 21. open, but which may be automatically reduced when it is necessary to close valve 21 and thus temporarily shut off the supply of liquid to tank 1 to prevent the level of liquid therein rising above the predetermined maximum height. In the apparatus here illustrated the relative variations in these opposing pressures on the two sides of diaphragm 23 are produced by intermittently exhausting the air or gas or other fluid in the upper chamber through a valve apparatus generally represented by C, in Figs. 1 and 1 and in detail in Fig. This apparatus comprises a tubular valve 27 and exhaust port 29 in the casing 10. Ordinarily, i. (3., while liquid is flowing to tank 1 through pipe 7, the necessary pressure is maintained above diaphragm 23 by air or gas entering through pipe 9 connected to nipple 9 in said casing 10. As shown pipe 9 is connected to pipe t which supplies compressed air to the stirrup operating cylinders 41, 1-1, but this arrangement is shown for sin'iplicity and said pipe 9 may be connected to some other separate source of more constant pressure if the fluctuations in pressure in pipe 4; are found to be too great. The essential point is that the normal fluid pres- 1P8 applied to the upper surface. of diaphragm 23 shall be always suliicient when tally exerted to overcome the liquid pressure on the under side of the diaphragm and normally hold valve 91 wide open so as to permit the onward flow of liquid to tank 1. to fill the bottles being successively connected thereto. Thoiug'h valve 21 is thus normally held wide open any excessively rapid inflow of liquid is prevented by the coimterpressure in tank 1.

In the particular Form of actuating valve (Figs. 1 and 1), here shown in Fig. 3 in detail, for controlling the pressure of fluid on the upper side oi. the diaphragm in the valve casino 8 there is a casing 10 mounted on the cover 1 of tank 1, connected at its upper end by tubular gland 11" to pipe 9. Packings S2 and 31 hearing; on tubular valve 27 prevent the compressed air in pipe 9 from escaping to the exhaust port 29, or flowing into tank 1, where the counterpressure is usually somewhat below that in pipe Packing 33 prevents the compressed air in pipes 11 and 412 from escaping through port 29 except when the port 28 is raised above packing 32 or port 35 is lowered below packing 33. These packings are held in position by glands 11*, 11 and 11 which are forced downward against the bottom of casing by screw cap 30.

Float 16 in tank 1 rests on the surface of the liquid therein and is adjustably connected to the lower end of tubular valve 27 by screw plug 3t which also closes the lower end of said tubular valve. Its upper end is open, as shown, and is always in communication with pipe 11. i

To avoid too sudden movements of valve 21 which might strain diaphragm 23, the dashpot apparatus composed of piston in cylinder 24: and connected to valve 21 by hollow piston rod 26 is provided. As the bore in 26 extends through both valve 21 and piston 25 it serves as a relief passage for the dashpot. If the area of piston 25 is made equal to that of a cross section of pipe-end 20, valve 21 is balanced even when closed, and so may be opened by a slight excess of pressure on the upper surface of diaphragm 23.

The operation of the described apparatus is as follows: Valve tube 27 is adjusted with reference to float 16 so that when the latter rests on the liquid in tank 1 at the desired level, port 28 will be just below packing 32. This allows compressed air from pipe 9 to pass through port 28 to the interior of valve 27, and thence through pipes 11 and 41-2 to the closed chamber above diaphragm 23 As the pressure in pipe 9 is maintained at a degree above that of the counterpressure in tank 1, which is approximately equal to that of the liquid in casing 8, supply valve 21 is now held open and the supply of carbonated fluid for normal. operation of the bottle filling machine flows into tank 1. If, however, the liquid level in tank 1 rises from any cause, float 16 rises with it, forcing tubular valve 27 upward, and the moment port 28 passes packing the supply of compressed air from pipe 9 through pipes 11 and 42 to the chamber abovediaphragm 23 is cut off. Not only is said chamber cut off from. the compressed air pressure, but it also is con nected to exhaust port 29. This instantly reduces the air pressure on the upper surface of diaphragm 23 and, as the liquid pressure on its under surface is substantially constant, the diaphragm rises, lifts valve 21 against the lower end 20 of supply pipe 1S), and shuts off further flow of liquid to tank 1; Whenever thereafter the flow of liquid from tank 1 to the bottles being filled has lowered. said liquid level therein back to normal, float 16 drops with it, pulling down tubular valve 27 until port 28 comes below packing 32, thereby restoring normal pressure on the upper surface of diaphri E which then falls, opening valve 21 and reestablishing the normal flow of liquid to tank 1. 1

If it is deemed advisable to provide means for automatically closing valve 21 when the liquid level in tank 1 falls nearly to the bottom, as in case of great leakage, and so prevent waste, this may be accomplished by locating another port in tubular valve 27 at a point such that just before float 16 touches the bottom of tank 1 said port will fall below packing 33 and exhaust all press ire above diaphragm 23, thus closing valve 2 Among the advantages of the invention may bcmentioned the positive control and accurate maintenance of the liquid level, independent of counter pressure variations in the tank, the possibility of accurately ad justing said level by graduatingthe connection between float 16 and valve 27, prevention of any flooding of the tank when the counterpressure falls from leakage of gas, and maintenance of a uniform speed of the bottle filling operations as a result of the constant liquid level in the tank.

All these things tend to avoid surging of the carbonated liquid and endless variations of pressure thereon, which is most important because that prevents liberation of ti eicontaned gases and insures full charges thereof being delivered with the bottled liquid.

Obviously other forms of liquid controlling valves B could be substituted for that shown, and other forms of air or gas or other fluid valve G, without materially modifying the above described general. method of operation, or departing from the underlying principle of the invention as above explained.

Thus other forms of motor devices for actuating the liquid control valve 21 n'iight be substituted for the flexible diaphragm 23, and other forms of fluid control valve 11'" ll be substituted for tubular valve 27. This latter form of valve, however, has certain advantages in that it can he moved through the flexible packings 31, 32, and 33 by the rathersmall force which float 16 is capable of exerting, and also in that it is a quick acting valve, due to its beingslightiy m balanced. This latter characteristic develops from the fact that there is an unbalanced pressure of compressed air from pipe 11 on the top of plug 3%. Therefore, when the tube 27 rises so that air begins to leak through port 23 above packing 32, slightly reducing the pressure in pipe 11, and consequently on the top of plug 3 1, the normal resistance of this unbalanced pressure to the further rise of tube and float reduced, and

the rapid coi'npletion of opening of port 28 is promptly ensured as the pressure in pipe 11 is more and more rapidly exhausted. Conversely, when the float 16 falls and port Q8 begins to open below packing 32 so that aif pressure is admitted again to pipe 11 from connection 0, this builds up pressure on top of plug 34f, and accelerates the downward travel of the valve, producing quick opening again.

This prompt and full opening of the air valve, to either the pressure inlet 9 or to the exhaust port 29, is highly beneficial in that it quickly, and sharply, varies the fluid pressure on the upper side of diaphragm 23, with the result that said diaphragm is quickly flexed to its fullest possible extent and consequent y the plate valve 21 is either given a quick tull openino', or is quickly closed from a position of hill opening. In this way there is avoided any wire-drawing of the carbonated liquid through a partly opened valve, which wircwlrawing would produce agitation of the liquid and consequent liberation of the contained gas-a result always to be avoided if possible.

laying described my invention, I claim:

1. In .a bottle filling machine comprising; a tank adapted to contain a liquid with which bottles are to be tilled and means for maintaining; a substantially uniform pressure of gas in the said tank, the combination, with said tank, of a conduit for supplying; said liquid to said tank, a valve con trolling; said conduit, and means for operat slid valve comprisin a pressure operatcd device connected to a source of fluid separate from said tank and a second valve in said connection, which said second valve is associated with said tank and operable by variations in the fluid level in said tank to either open said connection to said separate source of fluid or to close the said connection and reduce the pressure on said pressure operated device.

2. In an apparatus of the character described the con'ibination of a container for liquids, a valve controlling the flow of liquid to said container, a motor device for opening and closing; said valve 0 erated by variations in pressure of an ad acent body of fluid distinct from, and not connected with, said liquid container, a source of supply of such fluid under pressure connected to said motor device, a valve casing provided with an exhaust port and containing a valve adapted to alternately connect said motor device with the said source of fluid pressure or with said. exhaust port, and a float in the liquid container operatively connected to said, fluid controlling valve whereby when said float rises, some of the fluid, the variations in pressure of which ctuate the motor of said liquid controlling valve, is discharged through said exhaust port and the liquid controlling valve closed,

and when the float falls, said exhaust portis closed, the valve operating motor is con nectcd to the source of fluid pressure, and the liquid controlling valve is opened.

The combination of a container adapted to hold a body of liquid under the pressure of a superimposed body of gas, a supply pipc extending to said container from a source of supply of liquid under pressure, a valve in said pipe adapted to be operated by variations in the opposing pressures ot said liquid and ot' a separate body of fluid not connected with said liquid container, at float in said container and means whereby the movements of said float may produce variations of: pressure in said last mentioned body of fluid.

4-. In a bottle filling; machine of the type described, the combination, with a pressure tank containing liquid and a pipe through which such liquid is supplied to said tank, of a valve controlling" the flow of liquid through said pipe normally closed by the back pressure of said liquid, a chamber associated with said valve separate from and tree from connection with said tank, a device for opening said valve operable by pressure in said chamber, a connection from said chamber to a source of supply of fluid under pressure higher than the above mentioned back pressure of the liquid in said tank, a second valve which is located in said connection and controls it, and a float in said tank controlling said second valve.

5. A conibination such as set forth in claim l in which said second fluid controlling valve is provided with an exhaust port. and connects said chamber to the source of fluid supply when said float falls at predetermined distance, but shuts oil said connection and opens said exhaust port from said chan'iher when said float rises a predetern'iined distance.

6. A quick acting valve apparatus for alternately admitting or exhausting fluid undcr pressure to or from a closed chainl'ier, which valve apparatus comprises, in combination, a casing adapted to be connected at one open end to said chamber, which easing contains an annular packing, and is pro vided with an inlet port on the side or said packing" furthest from its open end, and with an outlet port on the opposite side of said packing, a tube mounted in and movable endwise through said packing, opening at one end into the open end of the casing, closed at its other end, and having a port in its side, and motor means for reciprocating said tube endwise through said packing so that said port may passfroni one side to the other of said packing.

7. A combination such as set forth in claim 6 in which the motor means comprises a float in a body of liquid subject to varia- FRED, "W MULLER.

tions of level.

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