US2630757A

US2630757A - Combined type series pump for flashable liquids

Info

Publication number: US2630757A
Application number: US17282A
Authority: US
Inventors: Cartier Effie Mae; Norman J Gundlach
Original assignee: INDEPENDENT ENGINEERING COMPAN
Current assignee: INDEPENDENT ENGINEERING COMPAN; INDEPENDENT ENGINEERING COMPANY Inc
Priority date: 1948-03-26
Filing date: 1948-03-26
Publication date: 1953-03-10
Anticipated expiration: 1970-03-10

Description

March 10, 1953 L.. R. CARTIER 2,630,757

COMBINED TYPE SERIES PUMP'FOR FLASHABLE LIQUIDS Filed March 26, 1948 /A/l/EA/ To E: lon/EL CART/ER;

Patented Mar. 10, 1953 COMBINED `rrrr: SERIES PUMP Fon FLASHABLE LIQUms Lionel R. Cartier,

OFallon, Ill.; Effie Mae Cartier and Norman J. Gundlach, executors of said Lionel R. Cartier, deceased, pendent Engineering Company,

assig'nors to Inde- Inc., OFallon,

Ill., a corporation of Illinois Application March 26, 1948, Serial No. 17,282 i Claims. (Cl. S-5) The present invention relates to a pump for flashable liquids. For example, the pump of this invention is especially valuable in connection with the pumping of liquid oxygen that has a very low boiling point, resulting in a problem of vapor locking in the pump due to evaporation of the liquid oxygen to vapor within the pumping chambers. Such vapor locking restrictsor prevents the pump from drawing in a full charge of liquid to be pumped.

It is an object of the invention to provide a pump that will not cause flashing of the liquid, without requiring the use of pressure above the liquid in the liquid supply tank.

It is a broad object of this invention to provide a pump that will prevent sudden vaporization, or indeed any substantial degree of vaporization, oi a highly volatile liquid being pumped, especially where such vaporization results from the increase in temperature on the suction stroke of the pump in the liquid drawn into the pumping chamber, sometimes coupled with a reduction in flash point of the liquid resulting from any substantial reduction in pressure on the liquid `entering the pumping chamber.

A specific object of the invention is to provide a pump having an intake loading means that will maintain a pressure on the liquid being taken into the pump to assure ,substantially full liquid charge to the pump, even `if some liquid in the pumping chamber evaporates as a result, for example, of heat generated onthe preceding compression stroke.

A more specific object of the invention is to provide a pump of the piston or plunger type,

having a loading means that causes the intake chamber to be loaded under a certain pressureY that will prevent obstruction of intake because of vaporization of the liquid. More particularly, it is an object of the invention to provide a pump of` the foregoing kind having a loading chamber that entraps a `charge of liquid but doesV not substantially increase its loading chamber is so interoperated with the pump that it positively discharges the entrapped amount of liquid into the intake chamber of the pump during the suction stroke.

A further object of the invention 1s to` attain the foregoing charging of the intake chamber of the pump by a loading means without increasing the temperature of the liquid, and to interrelate the operation of the loading means, so that the loading chamber may be charged with liquid during the compression stroke of the pump, and may eject the charge ofliquid, by application temperature; and which of pressure, into the intake chamber during the suction stroke.

A particular object of the invention is to provide, in connection with a plunger type of pump, a loading chamber that obtains a charge o liquid by moving against the liquid, and without substantial increase of temperature during the charging process.

Other objects of the invention will appear in the description to follow,

In the drawings:

Fig. 1 is an elevation of the pump; and

Fig. 2 and Fig. 3 are, respectively, upper and lower diametrical sections of the pump.

The pump comprises a main cylinder Ill that h'as a bore from end to end providing various cylindricalV chambers, as will appear. (The term cylinder used herein is not speciiically limited to circular shapes, although for conventionally-` known reasons, pump cylinders are usually circular in cross section.) The lower end of the pump cylinder is of reduced diameter to provide a pump or displacement chamber I2, wherein a piston or plunger reciprocates Ias will appear. At the upper end of the displacement chamber I2, the bore flares outwardly at I3 to provide a seat for a tapered packing seat element. This aring portion I3 terminates in a somewhat wider cylindrical portion I4 to receive packing. Above the packing portion I4, the bore widens out to a diameter I5 that may continue evenly to the top of the main pump cylinder I0.

A plunger or displacement member, here in the form of a piston I8, is attached to a piston rod I9, `and is disposed within the displacement chamber I2. The piston rod has a reduced extension that is threaded as at20, and over this reduced extension place by a nut 2l. It is preferred to use the illustrated structure of the piston I8 with the packing rings, rather than a plunger with clear--` then applied above the packing seat 23, and with-- in the packing area of the pump cylinder bore.-

the piston may be built up `by a plurality of rings formed by alternate brass and leather washers or carbonrings clamped intoV with the flare t3. The packing seat '23 :may beA A packing gland 25 is applied above this packing, This packing gland is shaped to receive a generally tubular packing gland extension 26 that is preferably rabbeted to fit over a projecting end on the primary packing gland 25. As indicated, the ypacking gland extension 26 is supplied with a plurality of radial ports 21, for a purpose to appear.

The upper end of the tubular packing gland extension 26 receives an upper 'piston rodadjusting gland 38, rabbeted for an intertas indicated. This upper adjusting gland is flanged outwardly at 3l above the top of thepump'cylinder I3, and may have a relatively loose t within the upper bore l5 of the .pump cylinder. As indicated, the piston rod I9 passes through the foregoing elements, and upper adjusting gland 30.

The outside surface of the upper partof 'the pump cylinder lll receives, on opposite sides, two tubular rod guides 33 that.-m'ay be slightlyiiattened at their contact surfaces against. the, pump cylinder I G. They are `secured to the pump cylinder, it having beenrfound that silversolder along theextended interfaces is sulicient forthe purpose. These two rod guide tubes project abovezthe'top of the-pump cylinder lil, and pass through the flange 3| of the upperadjusting gland 30, -wh-ich may slide on the tubes. Above the flange 3|, the two tubes .are ceive packing ring adjusting caps ..35 thatm-ay be turned, they-.being lfiexagonal in external shape,vto force the ange .3i and the severalelements offthepacking extension down to compress the packing 24 properly against the piston rod I9 to prevent leakage.

The piston rod adjusting gland 3.5 has a recess 31 inits upper surface. This recess isadapted to receive packing fastened firmly into. position by a packing gland 39, that is attached .by screws 40fto the uppersurface of `theupper gland .30. This affords-a packing gland at the top .of the piston-rod.

The-piston rod I9, at its upper end, is reduced and threaded, asshown at 42. A crosshead type of -adapter 43 vis threaded overthe threaded extensionr42, and above this the piston rod .is threaded into adrive member 44, by means of which .the piston maybe attached to.a suitable source of power for its reciprocation. .The drive.

member 44 is inset into a recess in the crosshead 43,'and these Vparts may-be welded together, 'as indicated at 45.

.The pump cylinder le, withinthe .upper part I5 of its bore, has a plurality of ports .46.through its wall. Adjacent its top, it has tapped openings 41 thatcanreceive screws for attachingthe pulnpvto` a support.

There is an expansible and contractible loading-chamber forming loading means connected with the displacement chamber i2. Ithere is illustrated in-the form of a xed piston member and a movable cylindertelescopedover the xed piston, butvit will be understood that this .choice of arrangementis-not essential. As illustrated, the bottom end of the displacement chamber I2 in Y.the .pump cylinder VIl] is .enlarged to provide an internally threaded portion that receives .a tubular extension 58, this. element .being threaded at .its upper end for interengagement with the aforesaid bottom end of the pump hexagonal ange 5l enables the two parts .to be joined. This tubular extension lhas its Youter end'designed to act as the xed plunger, over which a liquid loader cylinder-52 is fitted toreabove vthe top of .the

threaded to recylinder IE). A.

-.33. The rods ciprocate. The liquid loader cylinder 52 is anged at 53. A pair of connecting rods 54 have their lower ends threaded into the flange 53 and locked by lock nuts 56. The rods 54 pass upwardly through guide tubes 51that are attached tothe outside wall of the pump cylinder ID similarly to the attachment of the upper guide tubes guide tubes 33, and pass through the crosshead l`43,fto whichthey are attached by suitable nuts 58 u'and 59. The lower threaded connection of these guide-rodsf54 .into the liquid loader cylin- -der 5'2 provides foran adjustment of the rods.

Also, adjustmentmay be made at the top in thezmanner obviouszfrom the drawings.

iThe `movable loader cylinder 52 has intake `.ports illthrough its. bottom wall. It also provides va guide for a loader Valve stem 6I, at the top constitutes the ixedpistomhas a bore extend-r ing fromend to end, so asto provide a passage between the loading and vdisplacement chambers. The upper-end of this bore is drilled down to -a valve seatv65 that may receive. a ball check valve 61. This .valveis enclosed into the upper part of the passage byatubular nut 88, the lower end of which .will prevent escape of the .ball rt1 but is'notched so as not to obstruct the flow of liquid pastrthe ball when itis in its upper position.

Below the valve seat66, the inner bore of the .element50 isreduced asat-, ,and terminates in Ya lower enlargement, the shoulder being notched at 1-0 to prevent a seal-off by a ball check valve`1l. This ball valve is retained by a fitting 12 that is tubular andprovides a suitable upper edge against which theball valve v1l may seat. Obviously, types of check valvesother than ball check valvesmay be used. The tting 1-2.is.threaded into the lower end ofthe fixed piston element .50. Itisevident that the tubular element V58, connecting the loading chamber with the displacement chamberlZ, provides an outlet from the `loading vchamber 4andan inlet to the displacement chamber.

The displacementfchamberlZ has an outlet 15 to ywhich a-short tube 15 is attached. This tube enters an elbow v1.1 that, in turn, receives a tting 18. The upper end of the elbow 11 aiTordsa shoulder providing a valve seat to receive a ball check valve 8| that is conned within a chamberilinfthe tting 13. The upper endlof this chamber is notched at V83. VA reduced .portion v'84 continues the opening through Y the `iltting 18 and aifordsan upper valve seat to receive an vrupperrball valve or checkV valve 86. This .upper ball valve is confined-by a `tting .81 ,threaded into the tting '18 and notched obstruction .of iiow when the'.

at 88 to prevent valve ball 86 rises againstit. An'outlettube 90 canllead. oir the .liquid vbeing. pumped.

Operation 54 continue upwardly through the the problems that are solved by this pump, because of its great likelihood of flashing into vapor during the pumping operation. In a typical installation, the pump will be supported so that the top of the liquid oxygen supply tank comes approximately to the bottom of the guide tubes 33. If the liquid tank is within an outer shell, then the pump may be given support by screws that enter holes 41 that are provided adjacent the top of the pump cylinder Il] on opposite sides thereof. The drive member 44 is attached to a suitable source of power so that it may be reciprocated. i

The drawings show the piston or plunger I8 in its upper position, that is to say, at the upper end of its stroke. In this position, the moving loader cylinder 52 is also in its upper position. It will be assumed that the displacement chamber I2 is charged with liquid oxygen.

When the piston descends, the liquid oxygen Within the chamber I2 is prevented from return egress through the fixed piston 50 because of the ball valve 6l that seats on the seat 65, and the additional ball valve 1I that seats in the tting 12. Consequently, liquid in the chamber I2 is ejected under pressure through the outlet 15. It then passes the ball valve 85 and the ball valve 88. These last two valves BI and 86 check the return flow of the liquid so that it is caused to pass into the outlet pipe 30.

In the downward movement or of the piston I37 which is attached to the crosshead member 43, the rods 54 are likewise caused to descend. These rods are attached to the moving cylinder 52, which therefore descends during the downstroke of the piston. In the down or charging stroke of the cylinder 52, the valve 62 will be caused to lift from the seat 63, so that an additional lcharge of liquid oxygen flows inwardly without substantial increase in temperature through the ports 60 to enter the moving cylinder 52. A factor involved in this action is the movement of the moving cylinder` 52 against the liquid, so that the inertia factor adds to the charging pressures instead of subtracting from them. This action is more likean entrapment of liquid than it is like the sucking of liquid produced by the suction stroke of the piston. As a result, there is no substantial opportunity for the oxygen to rlash into vapor as a result of serious temperature increase or pressure drop.

When the piston I8 reaches the bottom of its stroke, the moving cylinder 52 will likewise be at the bottom ci its stroke, and a new charge of liquid will be entrapped within the moving cylinder 52. Incidentally, the check valve 1I prevents the descent of the moving cylinder 52 from drawing liquid downwardly. When the moving cylinder 52 is at the bottom of its stroke, the valve 63 again clos-es, and will be maintained closed thereafter during the upstrcke, by action of the entracped liquid against it.

Thereafter, the piston I8 will be caused to ascend again on a suction stroke, and also the moving cylinder 52 will be caused to ascend at the same time on its discharging stroke. The normal suction action of the piston I8 in the present pump becomes more of a withdrawal action that permits liquid, previously entrapped by the moving cylinder 52, to enter the displacement chamber I2. The ascent of the moving cylinder 52 along the fixed piston causes the liquid entrapped by the valve B2 within the moving cylinder 52 to be moved upwardly, without reduction of pressure or rise of temperature to any subpressure stroke stantial degree, past the check valves 1I and 51 to charge the piston chamber I2. The two check valves prevent return flow of the liquid from the chamber.

With this arrangement, the liquid is initially entrapped Within the cylinder 52 without substantial rise in temperature or reduction in pressure to cause it to flash therein. Then it is positively discharged into the pumping chamber I2,` so that, even if there is sufcient heat in the pumping chamber I2 from the previous compression stroke, and consequent flashing of some liquid into vapor, the charging force will nevertheless cause full charging of the pumping chamber with liquid. It may be observed that the diameter of the fixed plunger 5D is greater than that of the movable piston I8. Hence the cylinder 52 can assuredly ll the displacement chamber I2 ci' the pump. The low pressures in the operation of the loading cylinder 52 may limit the amount of liquid taken into it on each loading operation, but its size is great enough yet to assure illing` of the displacement chamber I2 with enough pressure to avoid or overcome the effects of hashing therein. Preferably, as shown, no sealing is used between the `cup 52 and the piston 5B, as. this makes the arrangement more flexible, and may provide an avenue of leakage for any excess of liquid in the cylinder 52 over the capacity of the displacement chamber.

Liquid is restrained from passing upwardly by the piston rod because of the packing 24. Such liquid as may escape around the packing 24 -to lwithin the packing gland extension 26 can readily escape through the

ports

21 and 46, as either a liquid or a gas, depending upon temperature and pressure conditions. The escape of liquid through the top of the pump is prevented by the presence of Ithe packing 3'1.

As already noted, the positional relationship of the cylinder 52 to the piston I5 is adjustable by means of the lower connection of the connecting rods 54 to the flange 53 of the moving cylinder 52, or by means of the upper connection including the nuts 51 and 58 that attach the rods 54 to the crosshead member 43.

The principal packing 24 may be tightened by turning down the packing nuts 36 that, as previously noted, have hexagonal exteriors, as shown in Fig. 1. 36 down will force the flange 3| of 'the topmost gland member 30 down. Such movement is transmitted through the extension 26 to the gland member 25 and thence to the packing 24. Furthermore, the upper packing gland 31 may be adjusted by turning the screws le down to tighten the same.

`it is fairly evident that the pump can be readily disassembled for repair or replacement'of any of its parts. And, ir" it is to be used in a place where it is not necessary to maintain the temperature conditions, the moving cylinder 52 may be disconnected, and thereafter the pump used in conventional manner.

What is claimed is:

1. In a pump for lashable liquids, a displacement chamber, an outlet therefrom, a displacement member movable inwardly and outwardly of the displacement chamber on pressure and suction strokes, respectively, a movable loading cylinder, a plunger iixedly connected with the displacement chamber, the loading cylinder being mounted telescopically over the loading plunger and movable over the same, to vary the internal capacity of the loading cylinder, passage For example, turning these cap nutsl means connecting the interior of vthe loading cylinder and the displacement'chamber, check valve means in the passage means admitting now from the cylinder to the displacement chamber, check valved passage means into the loading cylinder to admit liquid to the loading cylinder when it moves in a capacity-enlarging direction, and means connecting the loading cylinder and displacement member for movementof the loading cylinder in a capacity-enlarging direction when the displacement member is moving on its pressure stroke, and for movement of the loading cylinder in a capacity-reducing direction When the displacement member is moving on its suction stroke.

2. The pump of claim l, wherein the passage means connectingv the loading cylinder andthe displacement chamber is disposed through the fixed plunger.

3. The pump of claim 1, wherein the means connecting the loading cylinder and displacement member comprises means to apply movement to the displacement member, and rod means connecting the movement applying means and the movable cylinder, and means to adjust the effective length of the rod means to vary the distance between the movement applying means and the cylinder and hence to vary the position of the movable cylinder with respect for any position of the displacement member.

4. In a pump for ,flashable liquid: a displacement chamber, a displacement member operable therein on-a suction stroke and a pressure stroke, an outlet from the chamber, loading means in the'form of'relatively movable, telescopic cylinder *andl plunger members, providing an expansible 'loading chamber, inlet check valve means opening through one "of said members to admit ilow into vthe loading chamber, means interconnecting the loading meansiand the displace-ment member, to expand the loading chamber onthe pressure stroke of the displacement member and to contract the loading chamber on the suction strolie of the displacement member, said loading chamber being expansible to collect a charge or liquid to be pumped, check-valved passage means connecting the loading chamber and the displacement chamber, the contraction of the loading chamber operating to force the charge through the passage means into the displacement chaniber, the inlet check `valve means o'f the loading means chamber including a freely movable tappet valve, opened by the liquid during the expanding movement of the loading chamber, and closed by the collected liquid during the contracting chamber.

5. In a pumping apparatus, a displacement Vchamber and a displacement member movable movement of the loading to its xed plunger collected in the chamber on pressure and suction strokes to decrease and increase respectively the volume of the chamber, an inlet into lthe chamber, an outlet from the chamber, an inilow valve means in the inlet, operable to admit inflow therethrough into the chamber but prevent outflow therethrough from the chamber, and means to load the chamber upon the suction stroke of the displacement member, including a loading cylinder member and Va Vloading plungerV member, one of which loading `members lis xedly attached to the displacement chamber and the other of which is movable, the loading members being intertted so that the relative movement between theloading plunger member and the loading cylinder member in one vdirection expands the fluid capacity ,of V.the loading cylinder member, and relative movement in the other direction contracts said fluid capacity, the inlet of the displacement chamber being connected into the loading cylinder, and being an outlet from the loading cylinder, an inlet to the loading cylinder having an inlow valve therein operable to admit inflow-but prevent outflow through the said inlet, the effective displacement of the loading cylinder being at least as great as that of the displacement chamber, and means interconnecting the movable loading member and the displacement member for movement or" the movable loading member in a direction to increase the .loading cylinder capacity when the displacement member moves on Vits pressure stroke, Aand to decrease said capacity when' the displacement member moves on its-suction stroke.

6. The combination of claim 5 in which the eiective displacement or" the loading cylinderis of the displacement chamber.

7. The combination of claim v5, and outoW valve means in lthe outlet of the displacement chamber operablefto admit outflow but-prevent inow through vthe outlet.

LIONEL R.. CARTIER.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 795,892 Caverno Aug. 1, 1905 949,940 Myers Feb. 22, 1910 1,034,353 Gerstenberg .July 30, 1912 1,046,167 AFloyd Dec. 3, 1912 1,930,731 Thompson. Oct. 17, 1933 `2,284,505 Zehner May 26, 1942 2,433,812 Hastings, Jr., etal. Dec.,30, 194'? FOREIGN PATENTS Number Country ,Date

509,169 France, v Jan. 27, 1920