US1308515A - wallace amd m - Google Patents

Description

G. F. WALLACE AND M. F. TIERNAN. METHOD OF AND APPARATUS FOR PUMPING CORROSIVE LIQUIDS.

APPLICATION HLED MAR. 14. 1918.

4 SHEETSSHEI:[ I.

Patented J My 1, 1919.

C. F. WALLACE AND IVL F. TIERNAN. METHOD OF AND APPARATUS FOR PUMPING CORROSIVE LIQUIDS.

APPLICATION FILED MAR. 14. I918. v I.308,515. Patented July1,1919.

4 SHEETSSHEET 2.

INVENTORs C. F. WALLAC'E AND M. F. TIERNAN.

METHOD OF AND APPARATUS FOR PUMPING CORROSIVE LIQUIDS. APPLICATION FILED MAR. 14. 19111. L38 5 1 5,, Patented July 1, 1919.

4 SHEETSSHEET 3.

IN VENTORS (Mr/e: E lla/Mae I 1 A? NEY C. F. WALLACE AND M. F. TIERNAN.

METHOD OF AND APPARATUS FOR PUMPING CORROSIVE LIQUIDS. APPLICATION FILED MAR. I4; 19H}.

moww, Patented July 1, 1919.

4 SHEETSSHEET 4.

I N VEN TORG (inf/6S E Wallace Ill till

Alli

- purrinn STATES rnrnui nut ient.

CHARLES F. WALLACE, 0F TQIVIIKINSVILLE, AND MARTIN F. TIERITAN, OF JAMAICA, NEW YORK.

Specification of Letters Patent.

METHOD OF AND APPARATUSQFOR PUMPING CORROSIITE LIQUIDS.

Patented July i, ioia.

Application filed March 1%, 1918. Serial No. $822,303.

' which a barrier of inert liquid is kept constantly interposed between the corrosive liquid and the pump chamber or cylinder of the pumping apparatus.

By our improvement We prevent the en trance of the corrosive liquid into the said.

pump chamber and thus prevent any damage to the pump, the piston and its packing.

It is well known that the pumping of corrosive liquids has a very deleterious effect upon the pump chamber and pistons, whenever the solutions come into contact therewith; This deleterious action is notonly due to the corrosive action of'the liquid as such,

but also to the fact that any material on the inside walls of the cylinder and the piston, which had been attacked while the solution was in contact therewith, is scraped oif by the piston when the latter makes its return stroke. Thus constantly fresh surfaces of the metal are exposed to the corroding action of the liquid, so that not only the cylinder walls and the piston rapidly deteriorate, but leakage of the solution occurs around the packing.

One of the objects of our invention is to do away with these disadvantages by entirely preventing the corrosive solution from entering the pump chambers-and providing a barrier consisting of a column of inert liquid between the said pump chamber and the corrosive solution. We cause the said barrier or column of inert liquid to be established and maintained by the action of the pump itself, theipump being so arranged that the )iston toward the end of its suction stroke raws a certain quantity of inert liquid. The corrosive liquid is-thus automatically forced away from the pump piston while the latter makes its suction strokeand thus forms the barrier. In introduclng the quantity of inert liquid, care 18 taken that the rate of supply thereof exceeds the rate of difi'usion of the liquids into each other.

Other objects of our invention will appear. from the following specification and claims.

Our invention is illustrated in the accompanying drawings. I

.Figure 1 of the said drawings is a diagrammatic view illustrating the principle of our invention.

Fig. 1 illustrates a modified construction of the, cylinder and piston installation with pipe connections.

Fig. *2 is a view partly in elevation and partly in vertical longitudinal cross section of a pumping system embodying our invention.

Fig. '3 is a plan view partly in section along the staggered line 3-3 of Fig. 2, also partly broken away to show the connection to the valve chambers.

Fig. 4 is a horizontal section through the upper part of the valve chamber along the line H of Fig. 5 showing the connection of the outlet valves to the pumping system.

Fig. 5 is a longitudinal cross section along the line 55 in Fig. 4:.

Fig. 6 is a cross section along the line 66 in Fig. 5 of the corrosive liquid admission valves.

Referring to the diagrammatic outline of our pumping system in Fig. 1, 5 represents .a pumping cylinder which is provided with a lining l and a cylinder head 6 held in position by nuts 7. Within the said cylinder 5 there is fitted areciprocating piston 1, which is made liquid tight by means of the usual stuffing box 2 and packing 3.

Within the said cylinder there is located a port 8, which communicates with a pipe 9. The said pipe 9 is intended to serve as a solution reservoir of rather large capacity andfor this purpose it is arranged in the shape of a coil 10 having a series of superimposed windings. A double valve cham'ber V is provided with a pair of valves 14' and 15, and the lowermost extremity of the said pipe line 9 enters into the said valve cham- All her below the valve A port or passa 20 in the valve chamber V leads from a port below the valve 15 to a point above the valve 14.

Connected to the chamber below the valve 1% is a pipe 13 which leads into a tank 11, which serves as a storage chamber for the corrosive solution 12 to be pumped, and connected to the chamber above the valve 15 is a discharge pipe 16. The above mentioned cylinder 5 is also provided with a second port 17 and connected to this port 17 is a pipe 18 provided with a check valve 19. the said pipe 18 serving for the introduction of inert liquid into the cylinder. The mate-- rial of pipes 9, 13 and 16, coils 10, valves 14 and 15, lining of valve chamber V and tank 11 is such that it is not attacked by the corrosive solution.

As an alternative for the port 17, I 111a;- provide a fitting 17 in the pipe 18 for con.- nection to the pipe 9, the said pipe 18 h aving a restricted portion 18*, as shown in Fig. 1

The operation is as follows:

When the piston 1 starts on its suction stroke it is evident that a certain quantity of corrosive solution 12 will be pumped up from the tank 11 and will pass through pipe -13 and under the valve 14:, which will be lifted up by the suction, into the coils 10 of the pipe 9. We make the capacity of the said coils 10 such that it is larger than that y of the pump chamber itself, so that no corrosive liquid can be drawn into the pump chamber.

As the piston 1 continues on its travel it opens the port 17 which communicates with the pipe line 18 and through which there is introduced into the pumping cylinder an inert liquid of any suitable nature, which has no corrosive action on the pumping cylinder and piston.

It is evident that the said inert liquid will fill" the pump chamber and that part of the pipe line 9 which is not occupied by the corrosive solution and will thus interpose a layer of inert solution between the piston in the pump cylinder and the said corrosive solution.

When the piston makesits return stroke it closes the-port 17 and the check valve 19 in the pipe line 18, preventing the inert liquid from being forced back again into the feed line. It will then exert pressure on the liquid remaining in the cylinder and will force it into the pipe line 9, which consequently forces a corresponding part of the corrosive solution out'of the outlet pipe 16, by reason of the fact that the inlet valve 14 is forced closed on' its seat while the outlet valve 15 is simultaneously opened, owing to the pressure exerted thereupon.

When the fitting having the restricted portion 18 is used, as shown in Fig. 1, in lieu of the arrangement shown in Fig. 1, the operation is substantially the same as above.

described, except that the inert liquid is drawn into the cylinder during the entire suction stroke, the area of the said port being proportioned to admit substantially the same volume of liquid during one stroke as would be admitted by the port 17 with the arrangement shown in Fig. 1.

With the next stroke of the pump the action of the mechanism will repeat itself as described above, it being evident that there is always a wall of inert liquid interposed between the corrosive liquid and the pump cylinder, so that the moving parts therein and the chamber itself will not be attacked by the said corrosive solution.

It will be appreciated that a small quan tity of inert liquid is drawn into the pumping chamber upon each suction stroke of the pump, and that the return of such liquid along the pipe 18 is prevented by the cheek value 19, from which it follows that small quantities of inert liquid are discharged from the pump cham'ber into the pipe 9 upon each pumping stroke when the device is in operation, thus continually renewing the inert liquid in the portion of the said pipe which is adjacent to the pumping chamber and producing a slow flow of such liquid along the pipe 9 and past the outlet valve 15, along and mixed with the corrosive liquid being pumped, the proportion, arrangement and adjustment of the parts be ing, as hereinbefore stated, such that the in-- ert liquid will be supplied to the pumping chamber and caused to flow llu refrom through the pipe 9 at a greater ra e than the rate of diffusion of the corrosive and inert liquids into each other.

Figs. 2, 3, 4, 5 and 6illustrate a form of apparatus Which we have found to be very eflicient for carrying out our method. The pumping unit P rests on a base plate 20 and is directly supported on a stand 21 of cast iron or other suitable material. Motion is romnmnicated to the pumping parts by means of a shaft 22 driven by any suitable prime mover (not shown). The said shaft rests in suitable bearings 23 and 24 and carries a worm, which meshes with the worm wheel 26 disposed upon a shaft 27. Th" shaft 27 transmits its motion to the pumping system by means of cranks 28, 28 and connecting rods 29, 29, which are suitably fastened to the cross-head 30, whieh i t is connected to the piston 31 of the double acting pump,

The pump is provided with two cylinders 32 and 32 arranged opposite to each other and provided with linings 33, 33. The said cylinders are closed by covers 37, 37 which are fastened to the cylinders by means of screws 38, 38. The other s de of the cylinder is provided with the usual stufling boxes 34, 31 and packing mateiial 35, 35, and the said packing material being compressed as desired by the press screws 36 and 36.

At the rear portion of each one of the said cylinders there is provided a port 39,39, by means of which the suction of the pump is exerted upon the liquid to be pumped. At a suitable distance in front of them are arranged the ports 40, 40 which serve for the introduction into the cylinders of the pumping system of the inert liquid. The said inert liquid is led into the cylinders 32, 32' by means of a pipe 41 which branches into the two arms 42, 42 as shown. Each of the respective arms is provided with a check valve 43, 43'. I

As shown in Fig. 2, the port 39' communicates with a pipe 44', which in turn communicates with a coil 45. This coil is composed of material unattacked by the corrosive solution to be pumped. The nature. of the corrosive solution to be pumped will determine the nature of the material which composes the said coil 45. Thus, for instance, in the case of pumping chlorin solutions, the said coils may be made of rubber tubing or silver tubing. The said coil All 45 and the corresponding coil 45, belonging to the second pump cylinder, are disposed within a space provided inthe casings 16, 46, the remainder 01 the said spaces being filledwith some suitable packing material 4:7, 47', which will allow a certain limited movement and expansion of the .said coils, while securely supporting them. As thus constructed it is clear that the pump proper can be made of cast iron or other suitable material, the coils being separate detachable units while preferably constructed of material that will not be attacked by the solution pumped, yet-may be made of any inexpensive suitable material which on deterioration may be replaced at a reasonable cost.

As shown in Figs. 4t and 5, the ends ot the said coils 15, 4.5 communicate respectively by means of nipples 18, 48", with the outlet valve chambers 49, 49, which are connected to each other by the passage 61 and discharge into the common (mtlet pipe 50, as shown in Figs. 3 and 4. The said outlet valve chambers 49, 49 communicate at their bottom by passages 62 and 62' with the inlet valve chambers'51, 51' shown in Fig. 6,

which are fed by the solution inlet pipe 52, which in turn communicates with a reservoir (not shown) containing the corrosive solution to be pumped. The valve chambers 51 and 51 are also connected by a passage 63. Valve disks 53, 53' are held on their seats by suitable springs 55 and 55. Likewise the valve disks 5% and 54' are normally held on their seats by springs as at 56.' It is obvious the valves must be constructed of material resisting the corrosive action of the liquid to be pumped, and tor this reason it has beenfound very desirable in practice to construct the valves as separate detacha ble units. As shown, the valve unit V is detachably secured to the pumping unit P by a bolt 60.

It will be evident that the operation of the system of pumping shown in Figs. 2,

3, 4, 5 and 6 is exactly the same as that ex plained when referring to the diagrammatic view of Fig. 1. lit is evident that at each stroke of the pump, liquid will be sucked in from the storage reservoir through the pipe line 52, the suction opening the valve 53" while closing the valve 54, whereby the corrosive solution is allowed to enter into the coil 45. While the piston continues its stroke, inert liquid is admitted into the cylinder 33through pipe 42' and port 40.

At the same time the corresponding valve 54: will be opened and a corresponding amount of solution forced out through the outlet pipe 50. At the same time the piston 31 is, on its return stroke, in the cylinder 33, and it therefore forces out of the cylinder the inert liquid contained therein. and received by the prior stroke. This results in forcing the corrosive liquid through the pipe 45, and opening the valve 54:, at the same timeclosing the valve 53, thus discharging the corrosive liquid through the outlet .plpe 50.

lit is, of course, obvious that the action of the pump is alternating, that is, on the same thus constitute an inert layer between thecorrosive liquid and the pump chamber.

1t is understood that we do not limit ourselves to the specific form of construction shown in Figs. 2, 3, A, 5 and 6, as it 1s evident that various modifications and changes of form may be introduced therein without departing from-the spirit 01' our invention. I

Having now describedour invention what we claim as new and desire to secure by Letters Patent is:

1. The method of pumping a corrosive liquid which consists in confining a body of corrosive liquid and another body of noncorrosive liquid adjacent thereto, the volume of corrosive liquid being greater than the volume of non-corrosive liquid, subjecting said bodies of liquid to suction to first supply additional non-corrosive liquid and additional corrosive liquid to their respective bodies, and second subjecting said bodies of liquids to pressure to force a portion of said non-corrosive liquid from the combinedbody thereof.

2. The method of pumping a corrosive liquid which consists in confining a body of corrosive liquid and another body of noncorrosive liquid adjacent thereto, first employing suction to supply the said liquids to their respective bodies, the rate of supply of non-corrosive liquid exceeding the liltt of diifusion of the liquids into each other. then employing pressure to move one body of liquid by means of the other.

3. In a device of the kind described, a piston pump, an intermediate connection between the pump and the source of liquid being pumped, means whereby upon one stroke of the pump the liquid will be drawn into said intermediate connection and upon the opposite stroke of the pump the liquid will be forced out of said connection, the relative volumes of the intermediate connect ion and the pump displacement being such that the liquid being pumped will never enter therein, and means for continually adding small quantities of liquid to the liquid within said intermediate connection.

4. In a device of the class described, a pumping device, a conduit through which a corrosive liquid may be made to flow, an inlet and a discharge valve for controlling the flow along said conduit, a conduit communicating with said first mentioned conduit between said valves and leading to said pumping device said latter conduit adapted to contain non-corrosive liquid, the capacity of which conduit is greater than the displacement per stroke of said pumping device, and means for causing a continual slow flow of non-corrosive liquid through said last mentioned conduit and into the stream of corrosive liquid flowing through said first mentioned conduit.

5. In a device of the class described, a pumping device, a conduit through which a corrosive liquid may be made to flow, an inlet and a discharge valve for controlling the flow along said conduit, a conduit communicating with said first mentioned conduit between said valves and leading to said pumping device and adapted to contain a non-corrosive liquid, and the capacity of which conduit is greater than the displacement per stroke of said pumping device, and means for supplying successive small quantities of non-corrosive liquid to the non-corrosive liquid contained within said last mentioned conduit.

6. In a device of the class described, a pumping device, a conduit through which a corrosive liquid may be made to flow, an inlet and a discharge valve for controlling.

the flow along said'conduit, a conduit communicating with said first mentioned conduit between said valves and leading to said pumping device and adapted to contain a non-corrosive liquid, and the capacity of which conduit is greater than the displacement per stroke of said pumping device, and means for supplying a small quantity of non-corrosive liquid to the pumping chamber on each stroke of said pumping device.

7. In a device of the class described, a pumping device, a conduit through which a corrosive liquid may be made to flow. an inlet and a discharge valve for controlling the flow along said conduit, a conduit communicating with said first mentioned conduit between said valves and leading to said pumping device and adapted to contain a noncorrosive liquid, the capacity of which conduit is greater than the displacement per stroke of said pumping device, a pipe through which a non-corrosive liquid may flow into the pumping chamber of said pumping device upon each suction stroke thereof, and a check valve for preventing the flow of non-corrosive liquid through said pipe in reverse direction.

8. In a device of the kind described, a pump comprising a cylinder, a piston, an intermediate connection between the cylinder and the source of liquid being pumped, valves whereby upon one movement of said piston liquid will be drawn into said intermediate connection'and upon the opposite movement the liquid will be forced out of said connection, the relative volumes of the intermediate connection and the piston dis placement being such that the liquid being pumped will never enter said cylinder, and means for continually adding small quantities of liquid to the liquid Within said intermediate connection.

9. In a device of the kind described, a pump comprising a cylinder, a piston, a detachable intermediate connection between said cylinder and the source of liquid being pumped, means for supplying successive small quantities of a neutral inert liquid to said cylinder, and valves actuated by the piston for controlling the flow of liquid to and from said intermediate connection.

10. In a device of the kind described, a pump comprising a piston, a coiled intermediate connection, a cylinder portion and an annular chambered ortion for inclosing said coiled intermediate connection.

11. In a device of the kind described, a pump comprising a piston, a detachable intermediate connection, a cylinder portion, a chamber independent of and within which said intermediate connection is located, and a valve structure for controlling the flow of liquid to and from said intermediate connectionl Leoenit tachable intermediate connection independent of and inclosed by the pump casing, and a valve structure detachably secured to said pump and connected to said intermediate connection, said valve structure being arranged to control the flow or liquid to and from said intermediate connection.

13. In a device of the kind described, a pump comprising a piston, an intermediate 7 connection, a base portion, and a body por tion chambered to inclose said intermediate connection and having a cylinder formed therein for said piston.

1a. In a device of the kind described, a pump comprising a piston, an intermediate connection, a base portion, and a body portion chambered to inclose said intermediate connection and having a cylinder formed therein for said piston, valves for controlling the flow of liquid to and from said intermediate connection, the valves and the intermediate connection being detachably secured to facilitate replacement and constructed of materials adapted to resist erosion by the liquid being pumped.

ln a device of the hind described, a pump comprising a piston, a cylinder, an

intermediate connection between the cylinder and the liquid being pumped, means for introducing .an inert liquid to said cylinder, and valves whereby upon one movement of said piston liquid will be drawn into said intermediate connection and the inert liquid will be permitted to enter said cylinder and upon the opposite movement of said piston the liquid drawn into the intermediate con* nection will be discharged therefrom.

16. lln a device of the kind described, a multiple pump having pistons, cylinders, intermediate connections associated with said cylinders and detachably connected thereto, and chambers independent of and within which said intermediate connections are housed, and a single valve structure detachably connected to the pump arranged to individually control the flow of liquid to and from each intermediate connection.

- lln witness whereof, we have hereunto set our hands at the borough oi llllanhattan, city and State of New York, this 1st day oi" March, 1918.

CHARLEF l l llllilifltil l. Millttlllhl F, Tlltllliltblld. ln the presence ol lsnenn ltronanns, llrrn ill, Gnanarr,

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