US2546434A - Automatic liquid drain - Google Patents

Description

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March 27, 1951 Filed Oct 9, 1945 March 27, 1951 R. E. FARNSWORTH AUTOMATIC LIQUID DRAIN 2 Sheets-Sheet 2 Filed Oct. 9, 1945 INVENTOR R.E- E IRNSWORTH ATTORN EY Patented Mar. 27, 1951 UNITED STATES rATENT OFFICE 8 Claims.

The invention relates to a device for draining means for effecting the removal of any liquid without involving a loss of gas or the lowering of its pressure.

Another object is to provide a liquid drain device which is constantly conditioned for the automatic removal of liquid from a chamber containing a gas under relatively high pressure.

A more specific object is to provide for the removal of liquid from a purging or liquid-trapping tank of a gas-compressing system.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth or be apparent in the following description thereof, and in the accompanying drawings, in which,

Figure l is an elevation of a gas-compressing system embodying the features of present inven provided chemically or electrolytically usually contain water vapor or other vapors 01' gases which may condense under the pressure finally imposed on the gas being compressed. The present method and means has been particularly designed for automatically removing any liquid from the bottom of a purge tank or the like without any loss of the gas or affecting the pressure in the compressor system including the tank, it being noted that compression pressures up to 3,000 pounds per square inch are frequently used charging free containers with compressed gas.

In the illustrated apparatus, the bottom l3 of the tank It is formed as a liquid-collecting basin having a bottom drain opening at which a drain pipe !5 is connected, said pipe having a T fitting tion, portions of certain elements of the apparatus being shown in section. 7

Figure 2 is an enlarged fragmentary sectional view at the stepped line 2-2 in Figure 1.

Figure 3 is a top view of a liquid trap element of the apparatus, the view being taken at the line 33 in Figure 1.

Figure 4 is a fragmentary sectional elevation taken at the line 4- 3 in Figure 3.

Figure 5 is a section at the line 5-5 in Figure 4.

Figure 6 is an enlarged fragmentary view at a balance beam of the system, liquid and gas valves of the structure being shown in axial section, and said valves being conditioned as when the liquid-removing means is inoperative.

Figure 7 is a view similar to Figure 5, but shows the liquid valve conditioned for a liquid flow therethrough and the gas valve in side elevation.

The liquid-draining device of my invention is particularly disclosed as being applied in a gascompressing system wherein a compressor II of multi-stage type is arranged to supply compressed gas through a pipe i2 into a tan; 83 from which the gas may be distributed under pressure through a discharge pipe it while any liquid carried by the inflowing gas collects in the bottom of the tank, such a tank being known in the art as a distributing or purge tank. One usual source of liquid deposited in a purge tank is the lubricant used in the compressor; said lubricant may, for instance, comprise water or an aqueous soap solution used as a lubricant in compressors for oxygen, or other lubricants used in compressors for other gases. Furthermore, air or supposedly pure gases interposed therein at its lower point and having the lowest opening thereof closed by a screw plug It; the plug it may be removed for a gravity draining of the tank l3 when the tank pressure is relatively low or completely relieved. A normally open shut-off valve H is provided in the pipe l5 for closing when the pipe i5 is not to be used or when the tank 13 is to be drained by a removal of the screw plug it. The gas supply pipe i2 is shown as extending substantially to the bottom of the tank cavity, While the tank discharge pipe It extends from an upper point of the tank cavity; this is a usual arrangement for purge tanks receiving and discharging gases under pressure and facilitates the separation of any liquid from the incoming gas.

The drain pipe [5 discharges into a gravity trap unit l8, and the top of the trap cavity is connected by means of a pipe 26 through a normally open valve 59 and a valve 25 to atmosphere or to the intake 22 for the compressor, the latter being shown. The bottom of the trap cavity is connected by a pipe 23 to a valve 24 through which trapped liquid may be discharged through a pipe 25 under atmospheric pressure and into a pipe 26 through which the liquid may be conveyed to apoint where it is wasted or used; the pipe 26 is shown as comprising a stand-pipe providing a funnel 26 at its top for receiving liquid falling from the bottom end of the pipe 25. It will be understood that the trap unit it and valve it are interposed in the liquid flow line provided by the pipes 15 and 23 and 25 taken in order.

It will now be particularly noted that the trap unit it comprises a flask member 21 providedwith a bail 28 by which it is suspended from one end of a, beam member 29 which is pivotally supported at an intermediate point thereof from a fixedly disposed hanger 3|, the beam being ately adjacent their connections to the flask maintained in a generally horizontal position by a suitable means such as a counterweight 32 mounted on its other end. The present counterweight 32 comprises a cylindrical bucket which is provided with a supporting bail 33 which it is hung on the beam end, and the cavity of the counterweight 32 may contain sand 36 and/or other suitable materials for providing an adjusted counter-balancing of the flask unit for its lowering after a predetermined weight of liquid is in the flask cavity. The weight of liquid required in the container 2? for lowering the trap unit it is preferabl such as will substantially half. fill the container, and such a lowering of the trap unit is arranged to open the normally closed valve 2 for the escape of liquid through the pipes 23 and 25 at a rate determined by the degree of opening of the valve 24 operating as aneedle valve.

To permit the required up and down move- .ment of the trap .unit, its connections with the pipes 15 and 2t and 23 must be appropriately flexible and offer aminimum or" resistance to the movement of the trap unit as the amount of liquid therein varies. ,As particularly illustrated, portions of the pipes 55 and 25 immediill are respectively formed as helical coils l and 20' which have their axes substantially parallel to the upright line of possible movement of the trap unit and offer a minimum resistance to such .movement; the present coils i5 and 20' are axially aligned and generally alike whereby an axial compression of one is generally compensated for by a like axially stretching of the other as the tra ,unit moves.

The liquid discharge pipe 23 is given the required flexibility the provision therein of. a helical portion 23', having its axis generally perpendicular to the line of movement of the trap unit. The pipes l5 and 2e and 23 may comprise relatively small and flexible tubing of required strength for the pressures which may exist therein.

In the disclosed trap structure, the connections for the pipes 15 and 28 and 23 are provided through a plug or cork 35 sealediy fixed in the neck 2'? of the flask 21, and said neck provides oppositely directed earstt to which the ends of the bail 28 are rigidly attached by and between nuts 3! threadedly engaging the ears. The top of the bail 28 is swingaoly looped over a suitable seat provided across onebeam end, a sininar mounting being provided for the counterweight bail at the other beam, end. lvlutually aligned trunnions 38 extend oppositely from an intermediate point of thebeam 29 above the center of gravity of the beam and its load, said trunnions providing downwardly-directed knife edges 38 for engaging seats at the bottoms of V notches 39 provided by members ll or the han er 3 By particular reference to the showings of Figures 2 and 6, it will be noted that the present hanger 3% comprises a-base member by which the hanger may be secured to a fixed support (not shown), and the members ll, which are generally C-shaped, are. bolted to the base at transverse flange portions 4! at their tops and provide. the notches 3?; at top points of their lower ends to provide a horizontal support axis for the beam. The hanger members ll mount the valve 2 by a clamped engagement of the valve body 2 2' between them in adjusted posi- --tion in a generally horizontal line; bolts 13 extend through" and between the hanger members 45 for securing the valve body in a longitudinally adjusted position on the hanger.

The body 2d of the valve 2% is generally tubular and has a stepped bore providing a seat for the conical tip of a reciprocable valve plug H which is movable through the larger bore portion, the valve assembly functioning as a needle valve. A compression connection a5 is provided for the pipe 23 at the extremity of the smaller bore portion, the arrangement'being such that the pressure in the pipe 23 is arranged to urge an unseating of the valve plug it. The larger body bore portion is enlarged immediately adjacent the valve seat, and the pipe is connected to the body at said enlarged bore portion for a lateral discharge or" liquid from t. e body through i this pipe. The stem of the plug lit extends axial" viding a flat plug-contacting face in a plane which preferably includes the axis of 1y from the valve body 24 through a suitable packing or stuffing box it.

It will now be noted that the extending end of the valve plug l -lie arranged for its constant bearing engagement with an upward extension or arm :31 of the beam 29, said extension proil extending swinging and center of gravity of the beam. When no liquid is to escape through the valve 24, the beam is arranged to be so positioned that the beam extension ll is operative to hold the valve shut against any liquid flow from the pipe '23. When the beam is rocked by reason of the sufficient accumulation of liquid in the flask '2? to pull down the beamend which carries the flask, the needle valve plug it is released for its pressure displ cement to the escape of liquid through and from the pipe 25.

The valve is is arranged to be open continuously during the operation of the present apparatus for effecting a very slight relief 0: the tank pressure through the pipe ill whereby the tank pressure may cause the expulsion of liquid from the bottom of the tank through the pipe portion leading to the flask Z? for its trapping in the'fiask. It will be'understood that t. e pressure in the trap system is arranged to be just enough lower than that in the tank l3 that the pressure difierential between the tank and flask is sufficient to expel liquid from the tank bottom as it is deposited thereat, said liquid being accompanied by a certain amount of the gas for escape through the valve It in accordance with the setting of the latter.

The valve 2i normallyprovides an open passage for the gas therethrough and arranged to be automatically closed by the action of the beam 2% as controlled by the position of the trap unit when the flask contains appreciably more than .the desired limited amount of liquid, as

may tend to occur on account of a pressure discharge of liquid from the bottom of the tank E3 following an accumulation of liquid in the tank 53 while there is no liquid flow through the apparatus, it being necessary that the liquid level in the flask be prevented from reaching the flask outlet to the pipefit through which gas normally escapes from the flask to, and through the valve Hi. When the valve ii is closed, the valve 2:3 is fully open, whereby the tank pressure will force the liquid from the trap to eventually so lower the liquid level in the trapas topermit a raising of the unit under the influence of the counterweight 32 to finally eilect an'opening of the valve 21 for the resumption of gas flow through the valve is and the func ioning of the rimary automaticcontrbl. -It will-be understood that when the present apparatus is operating for compressing a gas and delivering the same through the tank l3, the trap unit will constantly hunt a position in which the drainage action therethrough is generally continuous, whereby the action comprises an automatic weighing-out process, and the bottom of the tank I3 is kept clear of liquid.

The present valve 2! comprises a body having threadeolly engaged sections it and defining a chamber 5! which is partitioned by a flexible diaphragm or disc Inlet and discharge openings 53 and 5 are provided in the bottom of the section 49 at tubular nipples for connecting the valve at a point in the pipe 23 between the valve 19 and the compressor intake 22. The inlet opening 53 is opposite the center of the disc 52 and terminates in a tubular boss 55 providing a valve seat at its end against which the disc is arranged to be mechanically engaged to close the gas escape line from the flask through the valve l9 and so prevent any fiow of liquid into the pipe 20.

The diaphragm 52 is normally spaced from the boss 55, and a member 56 is slidably engaged through the section id for projection against the diaphragm center to positively seat a diaphragm against tie boss in its passageclosing position. The member 5% has a discengaging head 56' and a smaller stern portion 56 extending from the section 48 for depressing engagement when the passage through the valve is to be closed. In the assembly of the present apparatus, the valve 2i is fixedly mounted with the upper end of its stem 5%" disposed for displacing engagement by the beam arm which carries the trap unit should the flask of the unit contain more than a permitted weight of liquid. The valve 2! may be fixedly supported in its operative position in any suitable manner, its vertically adjusted support from an arm 5? depending from a hanger member ll being particularly shown whereby this valve is unitarily associated with the valve 2 It will now be particularly noted and understood that the present device is usable in connection with purge tanks from which many different kinds of gases are supplied for supplying free containers with the gas. For example, a gas to be so handled may comprise acetylene, oxygen, nitrogen, helium, hydrogen, sulphur dioxide, carbon dioxide, and others, most of such gases being either injurious to life and/or being too valuable to waste; the disclosed connection of the pipe 20 to the intake of the compressor ii is therefore usually desirable as a means to salvaging the gas escaping through the valve l9. Also, in

applying the present device to gas-compressing systems handling different gases, the delivery pressures of the different gases handled may vary considerably, hence the disclosed use of a regulator type valve for controlling the gas and liquid flow to and through the weighing-out flask 2? provides for a ready adaptation of the same device to high-compression apparatus for different gases by reason of the permitted adjustability of the valve [9 to provide an appropriate liquid-purging action with respect to a tank l3.

From the foregoin description taken in connection with the accompanying drawings, the advantages of the construction and use or" the present device will be readily understood by those skilled in the art to which the invention appertains. While I have described the principle of operation, together with an arrangement which 6 I now consider to comprise a preferred embodiment thereof, I desire to have it understood that the disclosure is primarily illustrated, and that such changes and developments may be made, whendesired, as fall within the scope of the following claims.

I claim:

1. In combination with a vessel in a flow line for compressed gas and in which liquid carried by the gas may be deposited, a discharge pipe for the deposited liquid, a liquid-discharge valve for said pipe, a liquid trap interposed in said pipe between its discharge valve and the vessel to receive the liquid, mealns supporting said trap for its lowering displacement as a unit when the trap contains more than a predetermined weight of the liquid, and means utilizing the position of the trap to so control said liquid-discharge valve that the weight of liquid in the trap is automatically held to a predetermined value.

2. In combination with a flow line for compressed gas, a vessel providing a basin in which liquid carried by the gas may be deposited, a fluiddischarge pipe from the bottom of the basin, a

liquid-discharge valve in said pipe, a liquid trap interposed in said pipe, and a valve means providing for a regulated constant and limited escape of gas from the trap whereby the fluid pressure in the trap is maintained at a value very slightly less than that of the vessel to provide a continuous limited flow of gas with the deposited liquid from the vessel into the trap while its normal gas pressure is maintained in the vessel and the liquid-discharge valve is open.

3. In combination with a flow line for compressed gas, a vessel providing a basin in which liquid carried by the gas may be deposited, a fluid-discharge pipe from the bottom of the basin, an adjustable liquid-discharge valve in said pipe, a liquid trap interposed in said pipe, a gas-discharge pipe leadin from said trap, and a regulator valve means in said gas-discharge pipe providing for a constant and adjustably limited escape of gas therethrough from the trap whereby the trap pressure is enough lower than the pressure in the vessel as .to provide a continuous and limited flow of gas and the deposited liquid from the vessel into the trap.

4. In combination with a flow line for 06hpressed gas, a vessel providing a basin in which liquid carried by the gas may be deposited, a iluid-discharge pipe from the bottom of the basin, a liquid-discharge valve in said pipe, a unitary liquid trap interposed in said pipe and yieldingly supported for its lowering when it c0ntains a predetermined weight of liquid, means providing for a constant and limited escape of gas from the trap for producin a flow of gas with deposited liquid from the vessel thereinto, and means whereby a lowered disposal of said trap conditions the liquid-discharge valve for the discharge of the liquid from the trap at a uniform rate when and while the weight of liquid in the trap has a predetermined value.

5. In combination with a flow line for highly.

compressed gas, a vessel providing a basin in which liquid carried by the gas may be depos. ited, a fluid-discharge pipe from the bottom of the basin, a liquid-discharge valve in said pipe, a liquid trap interposed in said pipe, a gas-dis charge pipe leading from said trap, a valve means in said gas-discharge pipe providing for a constant and adjustably limited escape of gas therethrough from the trap, means supporting said trap for its lowering as a unit when the weight ofliquid therein reaches a predetermined value, and means for actuation by the lowered trap to open the liquid-discharge valve for the discharge of liquid from the trap by the action of the trap pressure.

6. A structure in accordance with claim 5 wherein the means supporting the trap for its lowering for opening the liquid-discharge valve comprises a counterbalanced beam member.

7. In combination with a flow line for compressed gas, a vessel providing a basin in which liquid carried by the gas maybe deposited, a fluid-discharge pipe from the bottom ofthe basin, a liquid-discharge valve in said pipe, a liquid trap interposed in said pipe, a gas-discharge pipe leading from said trap, means in said gas-discharge pipe providing for a constant and limited escape of gas therethrough from the trap, means supporting said trap for its lowering when the Weight of liquid therein exceeds a predetermined value, means for normal actuation by the lowered trap to open the liquid-discharge valve for the discharge of liquid from the trap by the action of the trap pressure, and means automatically operative to close said gas-discharge pipe beyond said opening when the weight of liquid in the trap substantially exceeds that required for ef- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 399,427 Moore Mar. 12, 1889 609,284 Losure Aug. 16, 1898 855,243 Green et al. May 28, 1907 925,438 Mount June 15, 1909 1,450,561 Parker Apr. 3, 1923 1,547,429 Ludeman July 28, 1925 1,581,636 Hilger Apr. 20, 1926 1,941,030 Williams Dec. 26, 1933 1,995,075 Murphy Mar. 19, 1935

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