US2246772A - Pump - Google Patents

Description

J. 5;. ABERCROMBIE 2,246,77 2-' June 24, 1941.

PUMP,

Filed Feb. 8, 1938 4 Sheets-Sheet 2 LIEJE- i i I 4/ James $.fikercromble; yvzmon ATTOIIRNEYS June 24, 1941.

J. S. ABERCROMBIE PUMP Filed Feb. 8. 1938 4 Sheets-Sheet 3 17 J8 29v 7 M 57 34 35 33 32 7 44 5/ I; I I 45\ l 55 as l 43 J6 5 J 36 3/ James l 5. flbercrombie.

INVENTOR BJW ATTORNEYS June 1941- J. 5. ABERCROMBIE PUMP Filed Feb. 8, 1938 4 Sheets-Sheet 4 I 28 IN I 3a l5 '39 J? M a 42 m a James S. fibercrom'bie.

INVENTOR ATTORNEYS Patented June James S. Abercrombie, Houston, Tex, assignor to Abercrombie Pump Company, Houston, Tex, a

corporation of Texas Application February 8, 1938, Serial No. 189,322

Claims.

This invention relates to pumps.

It will be found particularly useful in pumps designed for pumping abrasive and corrosive fluids of thegeneral type disclosed by Letters Patent of the United States to Charles D. Stephens 1,832,258, dated November 1'7, 1931. A conventional pump of this type adapted for use as a mud or slush pump in deep well drilling includes a barrel, inlet and outlet means therefor controlled by. inlet and outlet valves, respectively, a hollow expansible member within the barrel,

and a reciprocable piston to actuate fluid confined within the expansible member to cause an expansion and contraction thereof whereby fluid is drawn into and forced out of the barrel.

It is highly desirable in pumps of this general type that the hollow expansi-ble pumping member remain in substantially the same position as it expands and contracts radially in all directions. It is highly objectionable for the hollow expansible pumping member to be substantially moved toward the intake or exhaust ports because such movement may result in the hollow expansible pumping member being blown through the port toward which it is moved.

This invention has for one of its general obiects theprovision of a new and improved pump wherein the expansible hollow pumping member will 'not move objectionably toward either the intake port or the exhaust porti It is also dangerous to permit solid matter in the slush being pumped to settle in the bottom of the barrel and thereby interfere with the free expansion of the hollow expansible pumping member; and this invention has for another of its general objects the provision of new and improved means to sweep the solid matter in the slush out of the barrel so that such deposits may not occur.

Otherobjects will hereinafter appear.

The problem of keeping the expansible hollow pumping member substantially in the same posiv tion as it expands and contracts has arisen principallybecause the pump barrel; must be made relatively small with respect to the hollow expansible pumping member, and when the barrel is relatively small the pump must be operated operated at a high speed because the slush can readily reach the exhaust port without carrying the expansible member along with it. And if the barrel be made relatively small and the pump made to pump slowly, the expansible member will not be moved toward the exhaust port on the exhaust stroke because the slush will have time within which to flow around the pumping member and into the exhaust port without. forcing the pumping member itself toward the exhaust port. But in actual practice the barrel cannot be made relatively large'because slush usually contains a substantial volume of gas and if the barrel is relatively large with respect to the displacement of the pumping member, the expansion and contraction of the expansible pumping member will serve merely to expand and contract the gas within the slush the barrel,

' and the quantity of liquid pumped, if any, will at relatively high speeds in order to pump the desired volume of slush. A relatively, small pump" barrel and a high speed of operation contribute,

to excessive movementoi the pumping member toward the. exhaust-port for the following reasons: If a largebarrel is used in a pump of this type, the pumping member will not be moved toward the exhaust port even tho the pump be be objectionably small. And as the barrel must be made small the pump must be operated at relatively high speeds to pump the desired volume of slush. 1}

In addition to the foregoing, if the exhaust valve and the inlet valve are held! open during the operation of the pump by stones or the like,

then the slush under high pressure on the outside of the outlet port will rush inwardly through the outlet port, through the barrel, and then through the inlet port, and if the barrel is relatively small, the slush will carry the pumping member into the inlet port. A number of pumping members have been thus ruptured.

It is also true that in the event the inlet valve alone is held open by a stone or the like, the pump on the stroke which would lotherwise be the exhaust stroke will force the mud back through the inlet valve against a pressure which is practically zero as compared with the extremely high pressure under which the fluid is normally discharged through the exhaust valve,

and this will cause therdischarge stroke to be extremely fast, whereby the mud will be forced back through the inlet valve, and if the pumping barrel is small the mud rushing toward the inlet opening will carry the expansible member against the inlet opening and force out through said opening.

To accomplish one of the general objects of this invention above stated, that is to prevent the objectionable movement of the pumping member toward either port, the pumping member in accordance with this invention has been taken out of the path of the fluid passing through the pumping barrel and placed in a chamber in pump is so constructed that the fluid on the discharge stroke rather than the inlet stroke will be made to wash out the bottom of the barrel, thereby not only washing the solid matter off the bottom of the barrel, but washing it off with a greater pressure differential and washing it completely out of the barrel. Thus, for example, in the case of a pump capable of delivering fluid at three thousand pounds per square inch pressure where the pressure actually being delivered is, say, two thousand pounds, there exists a differential possibility of one thousand pounds pressure available for washing the debris out of the barrel on the discharge stroke, as against perhaps two to five pounds where the washing takes place on the intake stroke.

In the drawings:

Fig. l is a longitudinal vertical cross section through one barrel of a pump constructed in accordance with this invention, showing the expansible member in contracted position.

Fig. 2 is a vertical cross section taken along the line 2--2 of Fig. 1.

Fig. 3 is a view similar to Fig. 1 showing the expansible member in partially expanded position with the exhaust valve open.

Fig. 4 is a view similar to Fig. 2 taken along the line 4-4 of Fig. 3.

Referring now more in detail to the drawings, the numeral l indicates the pump barrel having a pumping chamber 2 therein, this chamber having an opening 3 at its lower end leading to the combined inlet and exhaust passageway 4. It is to be noted that at the point at which the passageway 4 empties into the chamber 2, the lower wall 5 of this passageway is disposed substantially tangentially with respect to the lower portion of the chamber 2 so that fluid entering or leaving through the opening 3 will enter or leave in a direction substantially tangential with respect to the pumping chamber.

Communicating with the passageway 4 and extending laterally therefrom is the intake pas sageway 6, and the combined intake and outlet passageway is continued as at 1, extending upwardly from the passageway 4 to substantially embrace one side of the pumping chamber 2,

v being separated therefrom by a relatively thin wall. This intake and outlet passageway I terminates at a position directly above the upper-, most portion of the pumping chamber for a purpose which will presently be set forth. The

8 which is constantly urged toward closed position by means of a spring 9, and which when closed seats against a valve seat member I]. The valve seat member "I is held in place by a cage which is in turn secured in position by means of a cap member [2. The cap member: I2 is fastened down by studs l3 and is provided with a ring [4 by which it may be lifted from its seat. In its lower surface the cap inlet passageway i is controlled by an inlet valve member l2 has a recess lined with rubber or some similar material [5, and adapted to receive the stem 16 of the valve 8. The lining material I 5 serves to prevent the stem l6 from making a metal to metal contact with the cap member l2 and thus serves to reduce the friction of operation of the pump. The passageway through the valve seat member leads to the inlet manifold I! through which fluid is drawn into the pump. The valve 8 is preferably provided with a sealing ring about its outer edge as indicated at l8 so that it may more perfectly seal against the valve seat member.

The intake and exhaust passageway at its upper end communicates with an outlet opening controlled by an exhaust valve I9 similar in all respects to the inlet valve just described. This valve I9 is adapted to seat against the valve seat member 20 which is in turn held in place by the cage 2|, the cap member 22 and the studs 23 in the same manner as just described in connection with the inlet valve. The cap .member 23 likewise has a ring 24 by which it may be lifted from position and the valve I9 is at all times urged toward seating position by means of a spring 25. The stem 26 of the valve I9 is adapted'to be received and guided by engagement within a recess in the lower surface of the cap member 22 which recess is lined by some shock absorbing material 21 such as rubber or the like. The exhaust valve I9 leads to the exhaust pipe 28 by which the fluid pumped is conducted to the well or to the point at which the pressure fluid is desired.

In addition to the opening 3 at the lower side of the pumping chamber, a second openit has been found desirable that the opening 3 be largerthan the opening 29, so that more fluid will be drawn into the chamber through the opening 3, than through the opening 29. As an explanation for this, it is noted that if the ports were of the same size, on the intake stroke there would theoretically be the same amount of fluid drawnin through the upper opening as through the lower opening, because the passageways to these respective openings from the inlet port are of substantially equal length. However, on the exhaust stroke if both openings were of the same size, a much greater amount of fluid would be forced outwardly through the upper opening than through the lower opening, because of the fact that the upper opening is much closer to the exhaust port, and fluid flowing through this upper opening does not have to overcome the frictional resistance encountered in flowing through the passageways 4 and I. If this were-permitted, there is some likelihood that the expanslble member might be forced against the upper exhaust opening 29 because of the much more rapid flow toward.

ceive the packing abutment ring 33 and form a stumng box. Within this stuffing box and against the ring 33 there is placed a packing 34 which in turn receives the gland 35. The member 30 is heldin its position in the end of the pumping barrel by means of a nut 38. The

gland 35 is urged against the packing 34 by means of a packing nut 31 likewise threaded into the member 30.

Passing through the stufllng box just described is a piston 35 which is movable longitudinally into and out of the pumping barrel. The member 35 has a part extending into the pumping barrel and provided with lateral heat dissipating fins 39 and at its inner end with an outwardly flanged portion 45 adapted to receive the inturned flange 4| on the inner end of the expansible pumping member 42. end, the outer flange 43 of the expansible pump- At its -opposite the opening at the lower side of the chamber. Neither will the fluid which is below the expansible member be forced to flow around the expansible member to reach an outlet port at the upper side thereof. In either instance, the fluid willflow toward the port which is closest. Thus, if ,the exhaust line should brea'k outside the pump, or if for some other reason the back pressure against which the pump is operating should be suddenly relieved and an. extremely fast exhaust stroke should be caused, the pumped fluid, flowing as it would in both directions out of the pumping chamber, would not tend to carry the expansible pumping member against one of these ports, but would tend to cause it to remain centrally located, and thus avoid the possibility of this member being forced into one of the ports and ruptured thereby.

ing member is clamped against the end portion of the pumping barrel by means of a clamping ring 44 having a thin flange 45. fltting within the end of the pumping member. This member 44 is held in clamping position by means of a head 46 secured in place by any suitable securing means. A plug 41 controls access to the filling passageway 48 for introducing pumping fluid into the interior of the expansible member 42,

and a plug 49 likewise controls the outlet pas-v drained from sageway 50 whereby fluid may be within the expansible member.

g The barrel head 46 is provided with an opening adapted to receive the packing abutment ring 5|, and provide a stufling box for the reception of the packing 52. The gland 53 which seats against the packing 52 is urged into position to nut 54. When this packing nut 54 is tightened it causes the packing 52 to form a seal about the piston rod 55 by which the piston 38 is moved into and out of the pumping barrel to cause the operation of the pump.

The barrel head 46 likewise carries the rods 56 having a clamping ring 51 at their inner ends whereby the inner flange of the expansible member may be clamped against the part 40 to form a seal between the inner end of the expansible member and the pumping barrel.

In connection with the foregoing, it is to be noted particularly that as the piston 38 and piston rod 55 are moved to the right, as seen in 'Figs. 1 and 3, the expansible pumping member will be expanded in the manner indicated in On the other hand, if the inlet valve should be held open and an extremely fast discharge stroke caused thereby, the same result will occur, because not only the outlet port, b'ut also fluid from the pumping chamber in such in-' stance would, therefore, have the same effect as in the previous example, and the expansible pumping member would not be forced against one of the outlet openings.

Inthe event thatboth the inlet and outlet valves should for some reason be held open, and a great amount of fluid from the outlet side of the pump be caused to flow rapidly through the pump to and through the inlet port, this would not, as in the previous constructions, cause the expansible pumping member to be forced against the inlet port and ruptured thereby, but instead this flow would take place throughv the passageways l and 6, and would not mate-- ble pumping, member to be forced against such opening, said member would not be forced through the opening'and punctured, because the fluid would still have the other outlet through which it might flow. The size of the ports 3 and 29 are, however, so proportioned that at extremely high pumping speeds the reduced size of the port 29 will cause a head loss between the interior of the chamber 2 and the outside of this port which will be substantially equal to the head loss through the port .3, and through the passageways 4 and I. The sleeve willthus be caused to expand equally in an upward and downward direction.

It will be appreciated that by the foregoing there has been provided a" device in which the flow outwardly through'the opening 29 so that th'e fluid which is above the expansible member at the end of the suction stroke will not be forced to flow around the expansible member and into tendency for the expansible pumping member to be blown through the inlet or exhaust opening has been substantially eliminated, and whereby it is consequently made'possible to materially reduce the size of the pumping chamber and increase the efficiency of the pump. By increasing the efficiency of the pump in reducing the clearance in the manner specified, it has been possible to build pumps of greater capacity and operating at higher speeds and higher pressures than heretofore without materially increasing the weight of the pump. The cost and weight of the pump for a givensize has also been materially reduced,

and a greater range of designs for high pressure operation made possible.

I claim:

1. A pump having a barrel, inlet means for said barrel, outlet means for said barrel, an expansible member within said barrel, means to expand and contract said member to draw fluid into said barrel through said inlet means and to expel it from said barrel through said outlet means, said} pansible member within said barrel, means toexpand and contract said member to draw fluid '20 direction substantially tangential to its inner' into said barrel through said inlet means, and to expel it from said barrel through said outlet means, said barrel including a fluid opening, entirely independent of said inlet and outlet means, through which fluid is introduced into and exhausted from said barrel in a direction substantially tangential to the inner surface of said barrel.

3. A pump including a barrel, inlet and outlet means for said barrel, a chamber in said barrel,

an expansible pumping member in said chamber todraw. fluid into saidbarrel through said inlet means and to discharge it from said barrel through said outlet means, said chamber having upper and lower ports, said upper port being smaller than said lower port, through which ports fluid may flow simultaneously into said chamber and simultaneously out of said chamber to control the movement of said pumping member in said chamber.

4. A pump including a barrel, inlet and outlet means for said barrel, a chamber in said barrel, an expansible pumping member in said chamber to draw fluid into said barrel through said inlet means and to discharge it from said barrel through said outlet means, said chamber having upper and lower ports, said upper port being smaller than said lower port, through which ports fluid may flow simultaneously into said chamber and simultaneously out of said chamber whereby said pumping member is prevented by the fluid from moving more than predetermined distances toward said ports. I

5. A pump including a barrel, a chamber in said barrel, an outlet means above said chamber, an inlet means below said outlet means, and an expansible pumping member in said chamber to draw fluid into said barrel through said inlet means and to discharge it from said barrel through said outlet means, a passageway in said barrel connecting said outlet means and said inlet means, a relatively small port in the upper portion of said chamber in direct communication with said outlet means, and a relatively large port in the lower portion of said chamber, said ports communicating with said passageway whereby fluid may flow simultaneously into and out of said chamber through said ports to control the movement of said member.

JAMES S. ABERCROMBIE.

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