US2903010A - Vacuum transfer of high density fluids - Google Patents

Description

Sept. 8, 1959 w. D. VEINOT' EI'AL VACUUM TRANSFER OF HIGH DENSITY FLUIDS Filed April 11 1955 3 Sheets-Sheet 1- INVENTORS (Jillian Vn'no? mrsm- Arron/5y;

Sept. 8, 1959 w. n. 'VEINOT E.TAL- 2,903,010

- VACUUM TRANSFER OF HIGH DENSITY FLUIDS Filed April 11, 1955 v 3 Sheets-Sheet 2 IN v/ENTORS PATENT HTTORNE') S Sept. 8, 1959 w. D. VEINOT ETAL 2,903,010

VACUUM TRANSFER OF HIGH DENSITY mums Filed April 11, 1955 V 3 Sheets-Sheet 3 Will/HM D. Vsmor CYR/L Ros/-50 5/ MM9 fa.

WUn er United States Patent VACUUM TRANSFER OF HIGH DENSITY FLUIDS William D. Veinot, Outremont, Quebec, and Cyril Robinson, Montreal, Quebec, Canada, assignors to McColl- Frontenac Oil Company Limited, Montreal, Quebec, Canada Application April 11, 1955, Serial No. 500,544

6 Claims. (Cl. 137-205) This invention relates to an improved method of transfer of high density fluids by vacuum flow through a system involving change of levels of flow of the fluid to the extent that vacuum normally applied to the flow system will not cause the fluid to flow through the change of levels to complete the transfer.

The invention is particularly concerned in the transfer of high density fluids such as tetra ethyl lead from one tank to another, such as from a tank car to a storage tank, where safety regulations either prohibit overhead transfer or specify a height above ground for the transfer piping which would prohibit the use of a vacuum to lift the fluid to the overhead height required by such regulations; and to overcome the added height and subsequent air pockets which are formed when the transfer line is taken underground from one tank to another over the intervening distance separating one tank from the other. When the high density fluid has to be transferred from say a tank car, under a roadway or intervening railroad tracks to a weigh tank or storage tank which is normally located above ground level, the fluid must first be taken up out of the tank through an inverted U then through an underground U then through another inverted U down into the tank. In order to overcome the difliculties of air trapped in the U bends a balance vacuum line and barometric leg is installed at the highest point of the U bend at the tank car and is connected to the vacuum pump of the fluid transfer system.

In order to fully understand the nature of this invention reference is made to the following detail specification and the drawings in which:

Fig. 1 is a diagrammatic showing of the invention installed between a tank car and a weigh tank.

Fig. 2 is a line diagram of a complete installation having the necessary control valves etc. for the satisfactory operation of the invention.

Figure 3 is a line diagram similar to Figure 2 but showing the vacuum balance leg brought underground.

Referring to the drawings, the line diagram shown in Fig. 1 covers a typical installation only and can be modified considerably to suit specific installations without departing from the spirit of this application. The tank 1 can be either a weigh tank or a storage tank while the tank 2 can be either a fixed tank whose location necessitates the installation of the present invention or it may be a vehicle or railroad tank car which cannot approach close enough to the tank 1 for normal transfer of fluid from one to the other because of such obstacles such as ;rail r oad tracks or roadways.

riprn ial conditions where the tank 2 can be te gloss an; tank 1, unloading of the tank 2 into nk 1 c 'acg'zzomplished by means of a direct conallaftiiinff l lowever, where the tanks 1 iCQ and 2 are separated as shown in the drawing the connecting pipe 3 has to be led underground in the form of a U tube with its connections to the tanks 1 and 2 forming inverted Us 4 and 5. It is in the inverted US that air pockets are formed. The pocket of air at 4 constitutes a break in the flow of the fluid thereby preventing a siphon-like flow to the tank l.

The normal vacuum obtained at the eductor 6 does not exceed 15 to 20 inches of mercury and due to the high density of the fluid, it is impossible to lift the fluid to the required height. In an attempt to operate the system without the balance line and barometric leg of this application, at the start of the operation, the fluid would rise to the top of the inverted U 4 and spill over, filling the lower part of U pipe 3 until the vacuum at point A is reduced by I1 and 11 to such an extent that it is insuflicient to overcome the lift at 11 The flow in the system would then stop.

In order to overcome this difliculty a barometric leg 7 is installed, extending upwards to the desired height from the highest point of the inverted U 4. The pipe leg 7 then drops down at 8 to a suitable height above ground level to extend overhead at 9, with a slight downward slope, to connect up with the eductor 6 and vacuum pump 10. Alternatively, the pipe leg 3 can drop a straight down underground to follow the fluid line 3 to connect up with the eductor 6 and vacuum pump 10, should that be found more convenient. This alternative vacuum line 9A is shown in Fig. 3 of the drawings. With the installation of the barometric leg 7 and balance line 8 and 9, complete evacuation of air from the top of the inverted U 4 is effected, permitting the complete filling up of the U pipe 3 with fluid from the tank 2. The lift in the system is now 12 and the system will continue to function to transfer the high density fluid as long as the vacuum at the eductor 6 exceeds the head h plus k One preferred embodiment of a permanent installation consists of the tank 1 having the inlet stand pipe 20 connected with the inverted U pipe 5 through the valve 21. One leg of the U pipe 5 is connected with the underground pipe 3 through a pair of valves 22 between which an H connection 23 leads to auxiliary storage tanks, not shown, controlled by the valves 24 and 25; the other leg of the U pipe 5 leads to the pump 10 through the valves 26 and 26A. Between the valve 26 and the pump 10 a T connection 27 has a branch leading to the eductor 6 whose through connection leads through the valve 28 to a circulating tank and then back to pump suction. The vacuum balance leg 3 and 9 (or alternatively 9A as shown in Fig. 3) is connected to the eductor vacuum manifold through valve 45. The branch 29 from the eductor 6 is provided with a check valve 30 and from there a vacuum line 31 controlled by the valve 32 leads to the stand pipe 20 at a point above the valve 21. Beyond the connection of the vacuum line 31 with the check valve 30, a valve 33 connects directly with the valves 34 and 35. The valve 34 controls the line 36, leading to an auxiliary storage tank, not shown, and through a valve 37, to a vent to the atmosphere. The valve 35 controls the vacuum line 38 leading to the top of the tank 1. A valve 39 in the line 33 controls a vent to atmosphere from this line.

The inverted U 4- comprises a swivel connection 40 to the vertical leg of the U pipe 3 and a swivel connection 41 to the stand pipe 42 of the tank 2 through the valve 43. The tank 2 is provided with the vent 46. Above the swivel connection 40 a valve 44 connects the top of the inverted U 4 with the barometric leg 7 and balance pipe 8 and 9 while a valve 45 is inserted at the opposite end of the line 9 adjacent its connection with the eductor 6 and pump 10.

In order to operate the system efliciently the operation of transferring high density fluid from tank 2 t tank 1 is carried out in the following manner.

After the tank 2 has been run into place it is con- 'nected up to the system by means of the stand pipe and swivel connections 40 and 41. All valves are closed. Valves 28, 33 and 35 are opened and pump til is started up to draw a vacuum on the tank 1. After a maximum vacuum has been obtained at the tank 1, valves 32, 26, 22 and 43 are opened and the system is then checked for leaks. if the system is tight, close valves 32 and 26 and open the valves 44 and 45 in the barometric leg 7 and balance line 9.

After vacuum gauges have indicated that a vacuum has been established in the tank car the vent on the top of the tank 2 is opened. Valves 44 and 45 are closed when vacuum gauges have indicated that all air has been evacuated from the top of the inverted U and valve 21 is then opened. Should the tank 1 be a weigh tank, the associated scale will indicate when the flow of fluid has started. If the tank is not a weigh tank then other gauges will indicate when the flow of fluid has started. The fluid in the tank 2 will continue to be evacuated into the system and to the tank 1 until the fluid drops to the level of the stand pipe 42.

By the use of the above described installation the hazards of transferring highly inflammable fluids such as tetra ethyl lead and the like are overcome in such a manner as to meet the requirements of restrictive 'egulations. The system disclosed also overcomes the difficulty of lifting a high density fluid such as tetra ethyl lead by vacuum means to the levels necessary when the system has to be taken underground in the manner shown.

What we claim is:

1. In a system for transferring heavy density fluid from the top of one tank to the top of a second tank comprising, a pipe extending in a series of reverse U bends underground below and between said tanks, a source of vacuum, means to connect the source of vacuum to the top of said second tank, the height of the U bends in said pipe being such that for a given magnitude of the source of vacuum applied to the said second tank, the heavy density fluid can be lifted to the height of the inverted U adjacent the first of said tanks and spill over but is insufficient to effect flow from the first to the second tank, and means to connect the source of vacuum temporarily to the top of the reverse U bend pipe adjacent the first of said tan is to evacuate the air from the said pipe and effect a continuous flow of fluid from the first to the second tank.

2. In a system for transferring heavy density fluid from the top of one tank to the top of a second tank comprising, a pipe extending in a series of reverse U bends underground below and between said tanks, a barometric leg extending upwards from the top of the reverse U bend in said pipe adjacent the first of said tanks, a source of vacuum, means to connect the source of vacuum to the top of said second tank, the height of the U bends in said pipe being such that for a given magnitude of the source of vacuum applied to the said second tank, the heavy density fluid can be lifted to the height of the inverted U adjacent the first of said tanks and spill over but is insuflicient to effect flow from the first to the second tank, and means to connect the source of vacuum temporarily to said barometric leg to evacuate the air therefrom and from pipe adjacent said first mentioned tank and effect a continuous flow of fluid from the first to the second tank.

3. In a system for transferring heavy density fiuid bends underground below and between said tanks, at barometric leg extending upwards from the top of the reverse U bend in said pipe adjacent the first of said tanks, a source of vacuum, a pipe connection connecting said barometric leg with the source of vacuum, valve means to cut off said pipe connectionfrorn the source of vacuum, means to connect the source of vacuum to the top of said second tank, the height of the U bends in said pipe being such that for a given magnitude of the source of vacuum applied to the said second tank, the heavy density fluid can be lifted to the height of the inverted U adjacent the first of said tanks and spill over but is insufiicient to effect flow from the first to the second tank, said valve means being opened temporarily to apply a vacuum to said barometric leg and evacuate the air therefrom and from the pipe adjacent said first mentioned tank to effect a continuous flow of the heavy density fluid through the system from the first to the second tank.

4. In a system for transferring heavy density fluid from the top of one tank to the top, of a second tank comprising, a pipe extending in a series of reverse U hends underground below and between said tanks, at barometric leg extending upwards from the top of the reverse U bend in said pipe adjacent the first of said tanks, a source of vacuum, means to connect the source of vacuum to the top of said second tank, the height of the U bends in said pipe being such that for a given magnitude of the source of vacuum applied to the said second tank, the heavy density fluid can be lifted to the height of the inverted U adjacent the first of said tanks and spill over but is insufficient to eifect flow from the first to the second tank, means to connect the source of vacuum temporarily to said barometric leg to evacuate the air therefrom and from the said pipe adjacent the said first mentioned tank, the vacuum created in said second tank thereafter drawing the fluid from the first tank through the reverse U bend pipe into the second tank.

5. in a system for transferring heavy density fluid from the top of one tank to the top of a second tank comprising, a pipe extending in a series of reverse U bends underground below and between said tanks, said pipe terminating in stand pipes extending downwards to adjacent the bottom of said tanks, a barometric leg extending upwards from the top of the reverse U bend in said pipe adjacent the first of said tanks, a source of vacuum, means to connect the source of vacuum to the top of said second tank, the height of the U bends in said pipe being such that for a given magnitude of the source of vacuum applied to the said second tank, the heavy density fluid can be lifted to the height of the inverted U adjacent the first of said tanks and spill over but is insufficient to effect flow from the first to the second tank, means to connect the source of vacuum temporarily to said barometric'leg to evacuate the air therefrom and from the piping adjacent the said first mentioned tank, the vacuum created in said second tank thereafter drawing the fluid from the first tank through the reverse U bend piping into the second tank.

6. In a system for transferring heavy density fluid from the top of one tank to the top of a second tank comprising, a pipe extending in a series of reverse U bends underground below and between said tanks, a barometric leg extending upwards from the top of the reverse U bend pipe adjacent the first of said tanks, a source of vacuum, a balance pipe connection connecting said barometric leg with the source of vacuum, valve means separating said barometric leg and balance pipe connection from said reverse U bend pipe and said second tank, means to connect the source of vacuum to the top of said second tank, the height of the U bends in said pipe being such that for a given magnitude of the source of vacuum applied to the said second tank, the heavy density fluid can be lifted to the height of the inverted U adjacent the first of said tanks and spill over but is insufficient to effect flow from the first to the second tank, said valve means when opened temporarily permitting evacuation of air from the said barometric leg and from the first mentioned tank and from said pipe and thereafter, when closed, shutting off the source of vacuum from the barometric leg and balance pipe connection and eifecting a continuous flow of the high density fluid through the reverse U bend pipe from the first to the second tank.

References Cited in the file of this patent UNITED STATES PATENTS Goetz Nov. 5, 1889 Thomas Aug. 27, 1935 Auter Oct. 22, 1935 Tokheim Sept. 29, 1936 Robertson Dec. 30, 1952

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