US2582753A - Apparatus for emptying reservoirs - Google Patents

Description

Patented Jan. 15, 1952 2,582,753 APPARATUS FOR EMPTYING RESERVOIRS Armand Pierre Herbelleau, Paris, France, assignor to Societe dite: Societe Nationale dEtude ct de Construction dc Moteurs dAviation, Societe Anonyme, Paris, France, a French company Application March 23, 1948, Serial No. 16,583 In France March 31, 1947 The present invention relates to apparatus for emptying a liquid from a tank.

It is an object of the invention to provide an apparatus which avoids the formation of an emulsion such as in known apparatus for emptying a liquid contained in a tank, wherein the suction opening of the emptying pump is uncovered and this pump sucks in air which mixes with the liquid which if the latter is emulsifiable, there is then, formation of an emulsion, which is undesirable.

According to the invention, an apparatus for emptying liquid from a tank comprises in combination with the tank, a pump for emptying the liquid from the tank and means for short-circuiting and connecting together the delivery side and the suction side of the said emptying pump as soon as the level of the liquid in the tank sinks below a predetermined level. In such an apparatus, the tank to be emptied is never completely emptied, and, as a result, the opening of the suction pipe of the emptying pump is always covered with liquid. Thus the emptying pump never sucks in air and emulsification is avoided in the emptied liquid.

According to the invention, also in the apparatus a first pipe leads from the bottom of the tank with a pump arranged in said pipe, and a second pipe branches from the said pipe on the suction side of said pump and bypasses said pump. A three-way valve device is common to the delivery side of said pump and the emptying pipe of the apparatus for putting into connection either the delivery side of the pump and the emptying pipe of the apparatus or the delivery side of the pump and the above said second pipe. Means are also provided for moving the valve of the three-way valve device into the position in which it makes connection between the delivery pipe of the pump and the emptying pipe of the apparatus when the liquid in the tank is above the said mentioned predetermined level and for moving the said valve in the other position in which it cuts the said connection and makes simultaneous connection between the delivery pipe of the pump and the above second pipe when the liquid in the tank sinks below the predetermined level.

Numerous apparatus can be constructed in accordance with the principle above defined and two types of apparatus of this kind are herein described by way of example.

According to one of these types, the three-way valve device includes a slide-valve movable in a cylinder. Said slide valve is subjected on'one of its faces to they action of a spring and on its opposite face, when the level in the tank is above Claims. (Cl. 103-11) a predetermined level, to the high pressure of the liquid of the tank as delivered by an auxiliary pump connected to a suction pipe which opens into the tank at the above predetermined level.

' A delivery pipe connected to said cylinder. is provided with a calibrated opening and delivers said liquid into the upper part of the tank. When the level of the liquid in the tank has sunk below said predetermined level, a low pressure air is delivered by the same pump and freely escapes into the upper part of the tank through said delivery pipe of the same auxiliary pump.

Numerous apparatus can be constructed in accordance with the principles above defined. The diagrammatic drawings appended, given by way of example and which do not in any way limit the scope of the present invention show, in Figs. 1-4, apparatus of the first form above described with an auxiliary pump and slide valve.

Fig. 1 is a diagrammatic view of a unit of apparatus of the first form, the plant being in that state of working corresponding to the periodof emptying of the tank.

Fig. 2 is similar to Fig. 1 and shows the same apparatus in that state of operation corresponding to the working of the emptying pump in short circuit with itself.

Fig. 3 shows, on an enlarged scale relative to the preceding figures, the bottom part of the cylinder of the three-way valve device.

Fig. 4 represents, in longitudinal section, one form of the emptying pump and the additional pump.

In these different figures, the same references denote the same parts.

I is the tank to be emptied, for example, an oil tank and 2 is the emptying pipe connected to the bottom of this tank. Said pipe 2 is permanentl connected to the suction pipe 3 of the emptying pump 4 of the oil tank and, temporarily,- through a by-pass 5 and a three-way valve device to the delivery pipe 6 of said emptying pump 4. The three way valve device includes a'cylinder I and a slide valve 8. 9 is the emptying pipe of the tank apparatus which is permanently connected to the cylinder 1.

I0 is an auxiliary pump which controls the slide-valve 8 in the cylinder I. Said pump It) includes a suction pipe 'H which opens into the tank at a level 12 above that of the lowest point. of said tank and a delivery pipe 13 opening at [4 into one of the bottoms of the cylinder 1. A pipe I6 is permanently connected at one of itsends to the bottom part of the cylinder 1 adjacent to the opening M through a calibrated port 24 and 25. A spring 2 suction of the said pump.

- 'side of said pump l7 and at its opposite end, said pipe 16 is open in the upper part of the tank I to be emptied.

Three ports I9, 20, 2| are arranged sidewise along the cylinder 1 with the port 19, the port nearest the plane bottom 22 of said cylinder 1 opposite to the bottom It, connected to the emptying pipe 9 of the apparatus; the intermediate port 20 is connected to the delivery pipe 6 of the emptying pump 4 and the port 2!, the port furthest removed fromrsaid bottom22, is connected to the by-pass 5 for the return to the suction of the said pump. The bottom part iii of the cylinder 1 is provided with above mentioned ports l4 and H.

The slide valve 8 is provided with two heads 6 is arranged betweenthe 1 and the head 24 and the bottom 22 of cylinder bottom 15 of the same head 25 is in front of the cylinder with 23 referring cluded between both heads 22 and 24.

. The apparatus operates as follows:

(w) As long as the 61 contained in the tank to be emptied covers the suction orifice l2 of the auxiliary pump I 0, the oil'delivered by this pump exerts its pressure on the head 25 of the slidevalve 8 and pushes it back, compressing the spring'26 carrying the slide-valve '8 into the position of Fig, 1 where it establishes communication between the delivery pipe 6 of the'pump 4 and the emptying pipe 9 whereby emptying is effected.

.(b) When the oil contained in the tank l uncovers the suction orifice l2 of the auxiliary pump 10, this pump only sucks in air, which flows through the calibrated orifice H of the delivery pipe IB at a speed much above that at which oil from the reservoir previously flowed out through the same orifice and brings about a sharp fall in pressure onthe free head 25 of the slide-valve 8 so that said slide-valve is pressed back by its spring 26 and places itself in the position of Fig.2 where it cuts the communication between the pipes 9 and 6, and where. it provides atthe' same time a connection between this delivery pipe 6 and the pipe 5 of return to the From that time, the evacuating pump 4 functions in the =circuit 3-43, 6.--20,1'23- -2l, 5--3 thus formed with the quantity of liquid which finds itself int-he bottom part of the tank I below the opening l2 of the suction pipe H of the auxiliary pump 10.

This working ceases as soon asthe'oil conto the section in,-

paratus or the delivery side of said pump and the above mentioned second pipe and means for moving the valve of said three-way valve device in the position in which it makes connection between said delivery pipe of said pump and said emptying pipe when the liquid in said tank is above a predetermined level and for moving said valve in the other position in which it cuts the said connection and makes connection between the deliverypipe of said pump and the above mentioned second pipe when the liquid in the tank has sunk below a predetermined level.

2,. Apparatus for .emptying liquid from a tank comprising in combination a tank, a first pipe leadingfrom the bottom of said tank, a first pump arranged in said pipe, a second pipe branchingfrom said pipe on the suction side of said pump and Icy-passing said pump, a third pipe leading from the inside of said tank at a predetermined level about the bottom of the same,- an auxiliary pump arranged in said third pipe, an emptying pipe forthe apparatus, a threeway- 'valve device comprising a cylinder connected. sidewise with the above mentioned first and tained in the tank covers again the suction orifice i2 of the auxiliary pump 40. V

Preferably, the emptying pump. and the auxiliary pump are driven by a common pump.

:Ili'ig. 4 showsa common driving shaft 2'! of the. two pump gear wheels 28 and 29 respective ing pipefor the apparatus, a three-way valve device common to the delivery side of said first pipe, said second pipe and said emptying pipe for putting into connection either the, delivery and emptying pipe of the apsecond pipes and said emptying pipe, a slidevalve arranged in said cylinder, a spring arranged between said slide-valve and one bottom of said cylinder, a delivery pipe connected to said second pump and issuing into the chamber of said cylinder which is opposite to said spring, a calibrated bleed pipe for evacuating in the upper part of'said tank liquid delivered into said chamber :by said auxiliary pump as long as the level of the liquid in the tank is above the upper end of said'third' pipe in said tank, said liquid being then under pressure in said chamber of said cylinder and keeping said slide valve against said spring in the position in which said slide valve connects said delivery pipe of said first pump with said emptying pipe of the apparatus and said calibrated bleed pipe evacuating afterwards air delivered bysaid second pump into the same chamber of said cylinder when the level of the liquid in the tank sinks below the said upper end of said third pipe with said air then escaping through the calibrated bleed pipe into the upper part of the tank, whereupon the corresponding fall in pressure in said chamber of the cylinder enables the spring to move the slide valve to cut the connection between the delivery pipe of the the emptying pipe of the apparatus and to make connection'between the delivery side of said first pump and the above mentioned second pipe.

1-3; Apparatus for emptying liquid. from a tank comprising' in combina on .a tank, a first pipe leading-from the bottom .of said tank,1a first. pump' arranged in said pipe, at second pipe branching from said pipe 0n the suction sidenf said pump and by-passing said pumpka third pipe'leading from the inside of said tank at-a predetermined level above the bottom of the same, an auxiliary pump arranged in said third pipe, an emptying pipefor the apparatus, a threeway valve device comprising a cylinderconnected sidewi'se with second pipes and said emptying'pipe of the'apparatus, .a slide-valve arranged in said cylinder, the said slide-valve being-provided with a central waisted portion, the depth of which is such that the Y. waisted portion-is adapted to bridge the entrance of said first'mentioned pipe to, and r the entrance of said' emptying pipelfrom, the cylinder at. one end of its travel andthe entrance of both said firstpipe and second by-pass pipes the above mentioned first and r at the other end of its travel, a spring arranged between said slide-valve and one bottom of said cylinder, said third pipe connected to said auxiliary pump being connected with the chamber of said cylinder which is opposite to said spring, a calibrated bleed pipe for evacuating into the upper part of the tank liquid delivered in said chamber by said auxiliary pump as long as the level of the liquid in the tank is above the upper end of said third pipe in said tank, said liquid being, at that time, under pressure in said chamber of said cylinder and keeping said slide valve against said spring in the position in which said slide valve connects said first pipe of said first pump with said emptying pipe of the apparatus and said calibrated bleed pipe evacuating afterwards air delivered by said auxiliary pump into the same chamber of said cylinder when the level of the liquid in said tank sinks below the upper end of said third pipe, said air then escaping through said calibrated bleed pipe into the upper part of said tank, whereupon the corresponding fall in pressure in said chamber of said cylinder enables said spring to move said slide valve to cut the connection between said first pipe of said first pump and said emptying pipe of the apparatus and to make connection between the delivery side of said first pump and the above mentioned pipe.

4. Apparatus for emptying liquid from a tank comprising in combination a tank, a first pipe leading from the bottom of said tank, a first pump arranged in said pipe, a second pipe branching from said pipe on the suction side of said pump and by-passing said pump, a third pipe leading from the inside of the tank at a predetermined level above the bottom of the same, an auxiliary pump arranged in said third pipe and driven by the same drive as the first pump, an emptying pipe for the apparatus, a

three-way valve device comprising a cylinder connected sidewise with the above mentioned first and second pipes and said emptying pipe, a slidevalve arranged in said cylinder, said slide-valve being provided with a central waisted portion, the depth of which is such that the waisted portion is adapted to bridge the entrance of said third pipe to, and the entrance of said emptying pipe from said cylinder at one end of its travel and the entrance of both said first pipe and said second by-pass pipe at the other end of its travel, a spring arranged between said slide-valve and one bottom of the said cylinder, said third pipe of said second pump issuing in the chamber of said cylinder which is opposite to said spring, a calibrated bleed pipe for evacuating into the upper part of said tank liquid delivered into said chamber by said auxiliary pump a long as the level of the liquid in the tank is above the upper end of said third pipe in said tank, said liquid being, at that time, under pressure in said chamber of said cylinderv and keeping said slide valve against the spring in the position in which said slide valve connects said first pipe of said first pump with said emptying pipe of the apparatus and the said calibrated bleed pipe evacuating afterwards air delivered by said auxiliary pump into the same chamber of said cylinder when the level of the liquid in said tank sinks below the upper end of said third-pipe, said air then escaping through said calibrated bleed pipe into the upper part of said tank, whereupon the corresponding fall in pressure in said chamber of said cylinder enables said spring to move said slide valve to cut the connection between said first pipe of said first pump and said emptying pipe of the apparatus and to make connection between said first pipe of said firstpump and the above mentioned second pipe.

5. Apparatu for emptying liquid from a tank comprising in combination a tank, a first pipe leading from the bottom of said tank, a first pump arranged in said pipe, a second pipe branching from said pipe on the suction side of said pump and by-passing said pump, a third pipe leading from the inside of said tank at a predetermined level above the bottom of the same, an auxiliary pump arranged in said third pipe and driven by the same drive as said first pump, an emptying pipe for the apparatus, a three-way valve device comprising a cylinder connected sidewise with the above first and second pipes and said emptying pipe, a slidevalve arranged in said cylinder, said slide-valve being provided with a central waisted portion, the depth of which is such that the waisted portion is adapted to bridge the entrance of said first mentioned pipe to, and the entrance of said emptying pipe from, said cylinder at one end of its travel and the entrance of said first pipe and said second by-pass pipe at the other end of its travel, a spring arranged between said slidevalve and one bottom of the said cylinder and said third pipe of said second pump issuing in the chamber of said cylinder which is opposite to said spring, a calibrated bleed pipe for evacuating into the upper part of said tank liquid delivered in said chamber by said auxiliary pump as long as the level of the liquid in the tank is above the upper end of said third pipe in said tank, said liquid being, at that time, under pressure in said chamber of said cylinder and keeping said slide valve against said spring in the position in which said slide valve connects said first pipe of said first pump with said emptying pipe of the apparatus and said calibrated bleed pipe evacuating afterwards air delivered by said auxiliary pump into the same chamber of said cylinder when the level of the liquid in the said tank sinks until the said upper end of said third pipe, said air then escaping through said calibrated bleed pipe into the upper part of said tank, whereupon the corresponding fall in pressure in said chamber of said cylinder enables said spring to move said slide valve to cut the connection between said first pipe of said first pump and said emptying pipe of the apparatus and to make connection between the delivery side of said first pump and the above mentioned second pipe, and the body of both pumps and the cylinder of said slide valve forming a unitary block.

ARMAND PIERRE HERBELLEAU.

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

UNITED STATES PATENTS Number Name Date 28,307 Sanderson et al. May 15, 1860 683,630 Westinghouse Oct. 1, 1901 1,699,194 Junkus Jan. 15, 1929 2,354,693 Martin Aug. 1, 1944

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