US1698127A - Air lift - Google Patents

Description

Jan. 8, 1929. 1,698,127

G. c. ENGSTRAND AIR LIFT Filed Aug. 5, 192 s INVENTOR:

Patented Jan. #8, 1929.

UNITED s'mrss a trace.

GUNNAR C. ENGSTRAND, 0F BROOKLYN, NEW YORK, ASSIGNOR; BY MESN'E ASSIGN- MENTS, TO SALVAGE PROCESS CORPORATION, OF NEW YORK, N. Y., A CORPORA- TION OF NEW YORK.

AIR LIFT. I

Application'filed August 5, 1926. Serial No. 127,342.

My invention has for its object to provide an apparatus and a method whereby viscous material can be pumped at acommercial pumping rate without interruption of service.

It has for its object to furnish an air lift emptying out in a suction tank from which tank the viscous material is pumped by a transfer pump. v

It has also for its object to provide an air lift supplied with an intake nozzle the-submergence of which can be varied as the nature for the material to be pumped may require;

I have discovered that at a certainsubmergence a certain material can be pumped at a commercial rate'of pumping. I have also discovered that when a commercial nozzle.

-By increasing or decreasing the depth to which the intake nozzle is submerged a'point is found at which the air admittance is so sealed that a sufficiently high-air inrush velocity will develop so as to break up the viscous material. I

My invention also provides means Whereby the vacuum in the'air lift can be temporarily increased above the vacuum existing in the suction' tank.

In the drawing ratus.

Figure 2 is an end elevation of thesame. Referring to the drawing in which like reference characters designate corresponding parts, 1 represents the air lift whlch terminates in the cylindrical fitting 2 fromv which fitting the air is, exhausted by the vacuum pump 4 through the line 3'.

The fitting 2 has the discharge leg 5 appended. The discharge. 5 is provided with the check valve 6 and is at its end connected to tank 9. I

The tank 9 is also connected withthe vacuum line 3 through the by pass line 7 which is provided with the pressure regulating valve'8.

The tank; 9 is also provided mospheric relief valve 10.

A strainer 11 extends longitudinally through the tank 9 and the material pumped has to pass through the same before it falls with the atentirely clog the line.

Figure 1 shows a plan view of the appato the bottom of the tank from which it is removed by the transfer pump 13 through the pipe line 12. The pump 13 is connected to the discharge pressure line 14, through which line the material pumped is finally disposed of. I

The intake end 15 is supplied with the internal reducing sleeve 16, and the pipe 17 forms a conductor through which atmospheric air is admitted to the formed annular space around said internal sleeve. A float 18 regulates valve 19 which is provided in the steam line to the pump.

The operation is as follows :The vacuum pump 4 is started and the suction end is insorted into the material to be pumped. By

means of lowering or raising the intake end a point will be found at which the bottom of the annular spacesurrounding the internal reducing sleeve is so sealed bythe material which is sucked up into the transmission line that the 'air in passing out from'the said annular space 'will attain a velocity sufficiently high to break up the viscous material-which passes into the transmission line.

A point is soon reached where the sucked up spray will interfere with the air current in the air lift line 1, whereupon the sucked up viscous .material will adhere to the inside of the air lift and in accumulating will soon It is to be noted that the vacuum in the air lift is the same as that existing in the tank 9 as long as the by pass valve 8 is open. This valve however is so; regulated and connected that. it will automatically close when the vacterial clogs thea-ir lift the vacuum will rapidly increase in the transmission line thus causing the clogging materialslug to travel through the line at a great velocity. It is to be noted that the valve 8 will not close before, the vacuum in the air lift reaches a certain point and it is therefore of the greatest importance to keep the tank 9 nearly full during the pumping so that the air space left in the tank will be small. By so doing it is possible to considerably reduce the capacity of the vacuum pump which intermittently must exhaust the air space in the suction tank in addition to the air lift until the vacuum necessary for the closing of the valve 8 is reached. I

The float, 18 which is housed in the tank is connected to the regulating valve 19 .in such a manner that the valve will. open or close'as the liquid level in the tank rises or recedes" and the pump will speed up or slow down accordingly. The liquid level in the tank is thus kept constant during'the pumping and the regulating float is so arranged that the air space in the tank is as small as possible. The time the vacuum pump requires to exhaust the air space decreases with its volume and as the pump must repeatedly exhaust this space in addition to the vacuum line whenever a sealing slug is built up in the line as previously described, a considerable reduction in the size of the vacuum pump will be attained when the air space is small.

The employment of a pressure regulating valve operated from the vacuum line makes it imperative to use a small air space with a small capacity vacuum pump. Were acheck valve instead of a pressure regulating valve used the size of the air space would be immaterial as the vacuum in the tank would always be equal to the maximum vacuum in the vacuum line and no repeated exhausting of the space would occur.

It is to be pointed out that if a slug is allower to form at the intake end so that the viscous material is not thoroughly mixed with air the slug will adhere to the transmission line most tenaciouslyand its progress will be so impeded that the pumping rate will become too slow for commercial purposes. By admitting air so that the viscous material is initially blown in a spray when entering the line the viscosity of the sealing slug is materially reduced and the pumping rate becomes commercial. A 4 hose will pump only five barrels an hour when the air is not allowed to mix with the material, but

it will pump more than fifty barrels an liourv when the viscous material is initially blown into a spray. a

I do not wish to myself to the specificdetails of construction as it is manifest that variations and modifications may be made in the adaptation of the device to various conditions without departing from the spirit and scope of my invention.

I claim i In a pumping apparatus a low suction tank, anair lift discharging in said tank, a by pass connecting the top of the suction tank to the air lift and a pressure regulating valve which will close the by pass when a predetermined vacuum is reached i the air lift and in the low suction tank.

GUNNAR O. ENGSTRAND.

be understood as limiting

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