US2330708A - Apparatus for withdrawing liquids from closed containers - Google Patents

Description

Sept. 28,1943. F. J. HARLOW 2,330,708 APPARATUS FOR IITHDRAWING LIQUIDS FROM CLOSED CONTAINERS Original Filed June 27, 1938 INVENTOR FREDERICK 1 lIlRl-OI BY Nu/40w, MIM

- v ATTORNEYS Patented Sept. 28, 1943 APPARATUS FOR'WITHDRAWING LiQUIDS FROM CLOSED CONTAINERS Frederick J. Harlow, Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware Original application June 27, 1938, Serial No. 216,148. Divided and this application April 18, 1940, Serial No. 330,403

1 Claim.

pumping liquefied petroleum gas, such as butane,

propane or mixtures thereof. The principal trouble has been due to the fact that the usual pumping methods and apparatus often resulted in gas lock due to expansion of the volatile liquids. This gas lock Ca'lSeS pumping to cease and the bearings to become dry and overheated. In addition to objectionable interruptions in operations, the pumps frequently become either partially or completely destroyed. In a pump and driving mechanism constructed in accordance with the present invention, various types of liquids including liquefied petroleum gas, gasoline, oils, varnishes, paints, and even tar, may be readily and efiiciently pumped from closed containers. It will be merely a matter of'mechanical skill to alter j the design of this equipment in order to use it effectively with liquids of different specific gravity, volatility, and viscosty.

The primary object of this invention is to provide apparatus which eliminates all possibility of gas lock in the pump when pumping volatile liquids out of vessels such as tank cars.

Another object of this invention is to equip tank cars for transporting highly volatile liquids with individual pumps which are adaptable to being actuated by a single source of power at unloading points. In this manner, the cost of the equipment for withdrawing the liquids is materially reduced as one motor may be used to evacuate a group of cars in succession.

- A further object of this invention is to provide apparatus for discharging the liquid contents of a container by means of a pump which is submerged in the liquid. By placing the pump in direct contact with the liquid, greater eificiency of operation is obtained; and, furthermore, higher pumping capacities may be maintained. Where liquefied petroleum gas is being pumped, the pressure in the container tends to assist the pump in forcing the liquid out; and, in this manner, the output of the pumping means is appreciably increased.

A still further object of this invention is to provide apparatus for discharging. liquids from containers, which apparatus is reasonable in first cost, inexpensive to operate and maintain, and thoroughly dependable to perform its intended functions.

The above and additional objects and advantages will be apparent from the following description and annexed drawing which respectively describe, and illustrate preferred embodiments of my invention; and wherein Figure l is a vertical cross sectional view of portions of a tank car with the apparatus comprising the present invention mounted thereon.

Figure 2 is an elevation view of another embodiment of my invention.

Referring to the drawing and more particularly to Figure 1 thereof, reference numerals l0 and II indicate the upper and' lower portions, respectively, of a container for liquefied petroleum gas, such as a railway tank car. Generally, containers and tank cars of this type are provided with coverings of cork or other suitabl insulating material 12 to control the temperature of the contents thereof. At the top of the car is an opening in the form of a collar l3 having an annular flanged ring it. 'A closure I5 i removably connected to ring H by a series of bolts IS. A dom I1 is supported on closure l5 and attached thereto by bolts l8. The dome is provided with a cover I9 which is pivotally mounted to the dome at 20.

A vertical shaft centrifugal pump is represented by pump rotors 2|, drive shaft 22, and tubular shaft housing 23. While it i apparent that various types of vertical shaft pumps may be employed advantageously for the purposes of this invention, I prefer to use a multi-stage centrifugal pump of the type illustrated. It is observed that the lower portion of-the pump extends into a sump 24 in the bottom of the tank car and is braced thereto by straps or brackets 25 which eliminate undesirable vibrations ofthe pump while the car is' in transit or during pumping operations. The shaft housing 23 is connected to closure I5 by a collar 28. A connector 29, concentric with the drive shaft and containing suitable frictionless bearings, is located in closure l5. This connector supports said drive shaft and is attached to the closure by a series-of stud bolts 30. A packing gland 3|, also concentric with the drive shaft and positioned adjacent the connector is used to prevent leakage. The upper end portion .of the drive shaft is splined indi cated at 32.

A plurality of withdrawal conduits 33 are in communication with the interior of housing 23, pass through closure l and terminate in T- unions 34. Each T-union is provided with an excess flow check valve 35 and a plug 36. In the dome, opposite plug 36, are openings 31 which are normally closed by plates 36, pivotally mounted to the dome by rivets 39.

The motive power for actuating the pump is supplied by a motor 46. which in the interests of safety should be of an explosion proof type. A chain 4|, connected to the motor by an eye bolt 42 is utilized to mount or removethe motor with respect to the pump. Two legs 43 of a tripod support are shown in the drawing. The upper end of each leg is pivotedto the motor at 44 while the lower portion 45 of each leg i forked to fit over the edge of the dome. Through the agency of set screws 46, the tripod legs 43 are rigidly maintained in position on the car dome. The motor drive shaft 41 is equipped with a universal joint 48 and terminates at its lower extremity in a splined socket 49 which engages splined shaft 32 of the pump.

The practice of this embodiment of my invention contemplates equipping tank cars for the transportation of liquefied petroleum gas with individual pumps. The pump, including drive shaft 22, housing 23, pump rotors 2|, and discharge conduits 33, is supported by closure i5 and installed as a unit in the cars. Neither the closure nor the pump is removed from the cars except when it is necessary to clean the interior of the car or to repair the pump. Tank cars which have been filled with liquefied petroleum gas, on reaching their destination, are run to a siding and stopped at an unloading point where the contents of the cars are to be withdrawn. At the unloading spot, a single motor 40 is utilized to successively empty each car. Individual tank car dome covers l9 are first opened and the motor, through the agency of chain M and eye bolt 42, is readily swung over the dome by any conventional means such as a crane. The motor is then lowered to operating position so that forked ends 45 of legs 43 of the motor tripod fit on the edge of the dome and are fastened thereto by set screws 46. At the same time splined socket 49 is placed in engagement with splined portion 32 of pump shaft 22.

Plates 38 are now moved away from openings 31 in the car dome and plugs 36 are removed from T-unions 34. Discharge hose is inserted through openings 31 and connected to the T- unions in place of the plugs. With valves 35 set Q to any desired degree of opening, the motor is sump 24 in the bottom of the tank car, the 5 highly objectionable possibility of gas lock in the pump experienced heretofore is completely eliminated. Pumping continues until the tank is substantially empty, at which time the motor is stopped; valves 35 are closed; the discharge hose is disconnected and plugs 36 are reinserted in the T-unions; stud bolts 46 are loosened; and the motor is raised upwardly and swung away from the car. The dome cover is then replaced and we are ready to proceed with the evacuation of another car.

Another embodiment of this invention is represented by Figure 2 of the drawing. Here instead of having a separate pump in each container or tank car, I propose to use but one pump and one motor at the storage plant or car terminus for the purpose of withdrawing'the contents of the car. The end portion of a tank car is indicated by reference numeral 50. A flexible conduit 5| is connected to the car by means ofa coupling 52. This conduit also communicates with the interior of chamber or receptacle 53 in which is mounted a pump of the type described above. The liquid is introduced by conduit 5| into chamber 53 where it is transmitted by the pump into discharge conduit 54. As in the case of the first described embodiment of the present invention, the pump rotors 2| are submerged below the liquid level in the chamber in order to prevent gas lock. Any vapors that may form in chamber 53 pass through gas conduit 55, coupling 56, and back to the tank car.

It is to be understood that the form of this invention, herewith shown and described, is to be taken as a preferred example of the same and that various changes in size, shape and arrangefurther that the theories of operation set out, although believed to be accurate, are not to be considered as the sole basis of the operativeness of this device, but that this .device does operate successively whether or not upon the principles described herein, this invention to be limited only by the appended claim.

I claim:

In apparatus for withdrawing a volatile liquid from a railway tank car having a sump in the bottom thereof, an outlet opposite the sump and a dome, the combination comprising a closure in sealed relation with the outlet; pumping means supported by the closure and extending into the sump, said pumping means including a plurality of rotors, a drive shaft operable from the exterior of the tank car for actuating the rotors, a housing in the container concentric with the drive shaft and a spline atthe upper end of the drive shaft; discharge conduit establishing communication with the housing and the exterior of the tank car; anda motor for operating the drive shaft, said motor being constructed and arranged to be removably mounted on the tank car dome and engage the spline on the drive shaft.

FREDERICK J. HARLOW.

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