US2532856A

US2532856A - Liquid feeding system

Info

Publication number: US2532856A
Application number: US683356A
Authority: US
Inventors: James L Ray
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1946-07-13
Filing date: 1946-07-13
Publication date: 1950-12-05
Anticipated expiration: 1967-12-05

Description

Dec. 5, 1950 J. L. RAY

LIQUID FEEDING SYSTEM Filed July 13, 1946 all/ 924a? v INVENTOR lovvvwo i, 9%1/3 ATTORNEY Patented Dec. 5, 1950 His-Chalmers Man f ct r h p Milwaukee, Wis, a corporation of Delaware Application: July I3, 1946, Serial No. 683,356

, 9 "Claims,

This invention relates to liquid feeding systems and the principal object of: the invention is the provision of newand improved systems of this un -1 V a Another objrectlof the. invention is theprovision of, a liquid feeding system which continuity of iiquid'feed ismaintained and, more particularly, to a system comprising more. than. 01 pump means and in which continuity of liquid-feed is maintainedwhen'one of the-pump means fails,

Another object of the. invention is the pro vision of a liquid feeding system in which an auxili-arypump means-is; caused to take the pumping load in response to failure of. the primary pumping means.

Another object of the invention is the provision 'of a, liquid. feeding system in which an auxiliary pump means is inmotion and in readiness to take. over the pumping load but unde normal conditions does: a negligible amount of work; and hence is; not subject tov the usual wear due to operation, nor subject to bre-a-kages: of the parts of the pump means. or its driving means, or failure of its driving means, and in general not subject to any conditions which are more likely to: cause failure of any kind when the pump means is under full, load.

Another object of the invention is the attainment of the foregoing 'objects with maximum simplicitm maximum certainty and a minimum of parts;

Other objects will appear as the description "of the invention proceeds.

The novel features of the invention andhow the objects are attained will appear from this specification I and the accompanying drawing showing one embodiment of the invention and forming a part of this. application, and all these novel features are intended to be pointed out in the claims.

In the drawings-g Fig. 1 is a principally diagrammatic. View, cerpain of the parts being in section, of a system em hpdying the invention, the parts Being in the posilti'on they assume when the system is in normal hperation; and

Fig. 2 is a View similar to 1 but with the parts in the position they assume when the primary pump means has failed.

Referring first more particularly to Fig. 1, a i h i' pump mean is i here hown as having its discharge outlet ll connected by a conduit i2, th u imm r ion f3 f d sch r e q i u The i d be fuel and the discharge 2 conduit I4 may lead to any apparatus inwhich the fuel is burned, but the liquid mayhe liquid other than fuel and be fed to any apparatus or place; where the liquid is utilized or disposed oi in any way. 7

auxiliary pump means. I5 has its discharge outlet I6 connected to the inlet ll of the primary pump means It. As here shown this connection comprises a conduit I8 connected, through a connection 19, to a conduit 20' which is in turn connected, through a connection 2l-, to a conduit 22 connected to the inlet, l -lof the primary pump means I0. Liquid may flow from a source of liquid here shown as a tank 23, through a conduit 24, through a: connection 25, to a conduit 26 connected to the inlet 21 of the auxiliary pump means I5.

The pump means In and [5 are preferably driven from. separate shafts, and the primary pump means Iii has a somewhat greater capacity than the auxiliary pump means l5. Preferably the pump means H1 and I5 are of the positive displacement type;

Bypass conduit means is provided around the m ry P p means Ill, this bypass comprising a conduit 2 78 connected to the connection I9 at one end to the inlet 29 of a check valve 30-. The outlet 31 of. the check valve has connected thereto one end of a conduit 32, the other end of which is connected to the connection I3. The check valve '39 is here shown as comprising a valve seat 33 with which a ball '34 is cooperable. The ball 34 may be biased to the seat 33 by a spring 3 5. The check valve 30 is constructed and arranged to prevent flow therethrough if the pressure at its outlet 3! is higher than at its inlet 2 9, and to permit flow therethrough when the pressure at its inlet 29 is greater than at its out let 3 'l-. Any form of check valve for performing these functions is suitable,

Bypass conduit means is also provided around the auxiliary pump means [5, this bypasscomprising a conduit 36 connected at one end to the connection 25 and at the other end to the inlet 3'! of a check valve 38. The outlet 39 of the check valve 38 has connected thereto an end of a conduit B0, the other end of which is connected to the connection 2 I. The check valve 38 is neife shown as comprising a valve seat 4| with which a hall 42 is cooperable. The ball 42 may be. biased to the seat by aspring 43. The check valve 38 is constructed and arranged to prevent flow thf ea through if the pressure at its outlet 39 is h at its inlet 31 and, to permit new therethrough when the pressure at its inlet '31 is greater than its outlet 39. Any form of check valve for performing these functions is suitable.

If desired, conduit means 44 connected to the discharge conduit at one end and leading to the tank 23 at the other, may be provided, a spring loaded valve 45 being interposed. The valve 45 is here shown as comprising a ball 46 pressed to a seat 41 by a spring 48. The spring 48 may be adjusted so that the ball 46 will not leave the seat 41 unless the pressure in the discharge conduit means I4 rises to a predetermined value in excess of a desired pressure in the conduit means. When the valve 45 opens, excess liquid flows back into the tank 23.

The operation of the system is as follows. Referring first to Fig. 1, in which the arrow indi cate the flow of liquid and the direction of flow, and assuming that the primary pump means it has the capacity of delivering 100 units of liquid flow to the discharge conduit means H! at the desired line pressure, and that the auxiliary pump means l5 has the capacity of delivering 90 units of liquid flow, it will be evident that. since the pump means Hi and I5 are connected in series by means of the conduits i8, 26 and 22, the auxiliary pump means 55 will deliver the liquid discharged thereby to the suction or inlet side of the primary pump means ill. The auxiliary pump means 55 draws then 90 units of li uid from the tank 23 through the

conduits

24, 25, these 90 units being discharged into the conduit [8, thence into the conduit 29. The primary pump means iii draws an additional 0 units of liquid from the conduit 24, into the conduit 35, thence through the check valve 38, through the conduit 40 into the conduit 22. The check valve 38 opens by reason of the negative pressure produced by the primary pump means in the conduit 22. Thus there are 100 'units of liquid flow in the conduit 22 and these 100 units are delivered to the discharge conduit I4. The check valve 33 is closed by reason of the higher liquid pressure in the conduit 32 than in the conduit 28, and hence flow is prevented in the bypass around the primary pump means Hi. It will be evident that under the hereinbefore described conditions, illustrated by Fig. 1, the auxiliary pump means does a negligible amount of work.

Referring now to Fig. 2, this indicates the primary pump means Ill as o t Of operation. the auxiliary pump means l5 continuing in operation. The liquid flow is then as indicated by the arrows. The auxiliary pump means I 5 now draws 9!) units of liquid through the

conduits

24, 26, discharging it through the conduit l8, through the now open check valve 30, into the conduit 32 and thence into the discharge conduit 4 at full line pressure. The check valve 38 orens and the check valve 38 closes because the primary pump means H3 is producing no difference in pressure as between the conduits I2, 22. The check valve 30 freely opens due to the pressure produced by the auxiliary pump means l5, and of course the check valve 38 prevents any flow from the auxiliary pump means I5 to the conduit 36.

The assumption that the ratio of capacities of the larger pump means to the smaller pump means is as one hundred to ninety was made merely for convenience in describing the operation, it being understood that this ratio may be made any other suitable value, either small or larger;

From the foregoing it will be apparent to those skilled in the art that the illustrated embodiment of the invention provides a new and improved liquid feeding system and accordingly accomplishes the objects of the invention. On the other hand, it will also be obvious to those skilled in the art that the illustrated embodiment of the invention may be variously changed and modified, or features thereof singly or collectively, embodied in other combinations than those illustrated without departing from the spirit of the invention, or sacrificing all of the advantages thereof, and that, accordingly, the disclosed embodiment is illustrative only, and the invention is not limited thereto.

It is claimed and desired to secure by Letters Patent:

1. A liquid feeding system, comprising: discharge conduit means; at least two pump means; conduit means for connecting said pump means in series to feed liquid to said discharge conduit means; bypass conduit means around a first of said pump means; check valve means, interposed in said bypass conduit means, so constructed and arranged that it prevents flow therethrough from the discharge side of said first pump means and permits flow in the opposite direction; second bypass conduit means around the second of said :pump means; and check valve means, interposed in said second bypass conduit means, so constructed and arranged that it permits flow therethrough to the inlet side of said first pump means and prevents flow in the opposite direction.

2. A liquid feeding system, comprising: discharge conduit means; at least two pump means of different capacities for feeding liquid to said discharge conduit means; means for so connecting said pump means that when both of said pump means are in operation a negligible part of the work in feeding liquid to said discharge conduit means is done by one of said pump means; and means so constructed and arranged that upon failure of the other of said pump means all of the work done in feeding liquid to said discharge means is done by said one of said pump means.

3. A li uid feeding system, comprising: discharge conduit means; at least two pump means, one of said pump means being of smaller capacity than the other; means for s0 connecting said pump means that when both said pump means are in operation a negli ible part of the work in feeding li uid to said discharge conduit means is done by said pump means of smaller capacity; and means so constructed and arranged that upon failure of the larger of said pump means all of the work done in feeding li uid to said discharge conduit means is done by said pump means of smaller capacity.

4. A liquid feeding system, comprising: dischar e conduit means; at least two pump means; conduit means for connecting said pump means in series to feed liquid to said discharge conduit means, a first of said pump means being of larger capacity than the se-"on'd of said pumn means, said second pump m ans being connected to discharge to the inlet of said first pump means: and means so constructed and arranged that upon failure of said first pump means said second pump means is connected to discharge directly to said discharge crnduit means.

5. A liquid feeding system, comprising: discharge conduit means: at least two pump means; conduit means for connecting said pum means in series to feed'liquid to said discharge conduit means, a first of s id pump means being of larger capacity than the second of said pump means,

second pump means being connected to discharge to the inlet of said first pump means; bypass conduit means around said first pump means; check valve means, interposed in said bypass conduit means, so constructed and arranged that it prevents flow therethrough from the discharge side of said first pump means and permits flow in the opposite direction; second by pass conduit means around said second pump means; and check valve means, interposed in said second bypass conduit means, so constructed and arranged that it permits flow therethrough to the inlet side of said first pump means and prevents flow in the opposite direction.

6. A liquid feeding system, comprising: discharge conduit means; at least two pump means; conduit means for connecting said pump means in series to feed liquid to said discharge conduit means, a first of said pump means being of larger capacity than the second of said pump means, said second pump means being connected to discharge to the inlet of said first pump means; conduit means for providing a bypass around said first of said pump means; check valve means, interposed in said bypass conduit means, so constructed and arranged that it is normally closed and opens in response to fluid pressure generated by the other of said pump means when said first pump means fails.

'7. A liquid feeding system, comprising: discharge conduit means; at least two pump means, one of said pump means being of smaller capacity than the other; means for connecting the pump means of smaller capacity to discharge to the inlet of the pump means of larger capacity so that when both said pump means are in operation a negligible part of the work in feeding liquid to said discharge conduit means is done by said pump means of smaller capacity; and means so constructed and arranged that upon failure of the larger of said pump means all of the work done in feeding liquid to said discharge conduit means is done by said pump means of smaller capacity.

8. A liquid feeding system, comprising: discharge conduit means; at least two pump means of difierent capacities in series for feeding liquid from a source to said discharge conduit means; means for so connecting said pump means that when both of said pump means are in operation 6 i a minor part of the work in feeding liquid to said discharge conduit means is done by one of said pump means, said connecting means including bypass conduit means from the source to a point between said pump means, and check valve means biased to closed position, interposed in said bypass conduit means and so constructed and arranged that when both of said pump means are in operation said check valve is open; and means so constructed and arranged that upon failure of the other of said pump means said one of said pump means is connected directly to said discharge conduit means and all of the work done in feeding liquid to said discharge conduit means is done by said one of said pump means.

9. A liquid feeding system, comprising: discharge conduit means; at least two pump means in series for feeding liquid from a source to said discharge conduit means, a first of said pump means being of larger capacity than the second of said pump means, said second pump means being connected to discharge to the inlet of said first pump means; bypass conduit means from the source to a point between said pump means; check valve means biased to closed positioned, interposed in said bypass conduit means and so constructed and arranged that when both of said pump means are in operation said check valve is open; and means so constructed and arranged that upon failure of the larger of said pump means said smaller one of said pump means is connected directly to said discharge conduit means.

' JAMES L. RAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,218,565 Vickers Oct. 22, 1940 2,366,388 Crosby Jan. 2, 1945 FOREIGN PATENTS Number Country Date 216,225 Switzerland 1941 703,569 France 1931