US3453964A

US3453964A - Casing valve assembly

Info

Publication number: US3453964A
Application number: US659467A
Authority: US
Inventors: Stanley K Hallworth
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1967-08-09
Filing date: 1967-08-09
Publication date: 1969-07-08
Anticipated expiration: 1986-07-08

Description

y 8, 1969 s. K. HALLWORTH 3,453,964

CASING VALVE ASSEMBLY Filed Aug. 9, 1967 86E INVENTOR:

26 1 84 ao av STANgEi; K. HALLWORTH I I 'ATT United States Patent US. Cl. 103-87 8 Claims ABSTRACT OF THE DISCLOSURE This specification discloses a housing assembly containing a pump and motor that are submerged in a tank or other container, such as a hold of a ship, for pumping liquid, especially liquefied gases and cryogenic liquids, into dockside storage tanks. Many of the liquefied gases, and more particularly their vapors, are flammable; and this invention has valve means that automatically close the inlet passage of the housing when the pump is lifted to remove it from the container. Another safety precaution includes provision for introducing an inert gas, such as nitrogen, into the housing assembly and into the motor bearings for purging them before removing the assembly from the liquid container.

Brief description of the invention This invention is an apparatus for pumping liquids from containers in which the pump and motor are submerged. They are enclosed in a housing assembly or casing which is lowered into the container with a discharge line connected with the housing assembly for carrying the liquid to a transport or storage facilities. Bearings of the submerged motor are cooled by the liquid which is being pumped, and there is provision for forcing gas through the lubrication passages to purge the bearings of the liquid preparatory to withdrawing of the assembly from the container after pumping liquid out of the container.

The housing assembly has a passage through which the liquid is pumped, and the inlet of this passage is at the bottom of the housing assembly and close to the bottom of the container so that substantially all of the liquid in the container can be pumped out. There are valve means for automatically closing the liquid passage of the housing assembly when the pump is lifted to move it from the container, and in the preferred construction the valve means automatically open again when the pump is lowered to the bottom of the container.

Another feature of the preferred construction is that the valve means include a plate which extends across the inlet opening of the passage to the pump, and this plate is movable toward and from the inlet opening to close and open the passage. There is a deflector on the top surface of the plate for deflecting liquid up into the inlet. The plate and deflector are part of an anti-vortex element which includes also vanes extending upward from the plate at angularly spaced locations around the plate, and there is :an annular ring in the upper end of the vanes.

A recess in the bottom end of the housing assembly provides space into which the annular ring and the vanes extend when the valve means are in closed position. Springs give the valve means a bias toward closed position and the springs and the parts that co-operate with them are all located above the vanes so as not to interfere with the flow of liquid over the top of the plate, and so as not to space the plate away from the bottom of the container in which the assembly is operating.

The motor and pump move up and down with respect to a casing of the housing assembly and the weight of these relatively movable elements is preferably used to 3,453,964 Patented vJuly 8, 1969 move the valve means into open position, against the bias of springs, when the assembly is lowered into contact with the bottom of a tank.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

Brief description of the drawing In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:

FIGURE 1 is a view, mostly in vertical section, and partly broken away, showing the apparatus of this invention;

FIGURE 2 is a fragmentary detail view of the lower right-hand part of the apparatus shown in FIGURE 1 with the parts in different positions; and

FIGURE 3 is a sectional view taken on the line 33 of FIGURE 1.

Detailed description of the invention The apparatus shown in the drawing includes a housing assembly 10 which includes an outer casing 12 having a top flange 14 to which is connected a cover plate 16 by a circle of bolts 18. At the lower end of the outer casing 12, there is an end fitting 22 attached to the casing by a circle of screws 24.

The upper part of the casing 12 may be fixed to the upper part of the tank or container by any suitable means such as flanges 12a. The lower part of the casing may be secured to the bottom of the tank by any suitable means such as cables etc.

Within the outer casing '12, and forming a part of the total assembly 10, is a motor pump assembly 28 including a motor 30 having an armature 32 attached to a hollow armature shaft 34 which rotates in anti-friction bearings 36 located both above and below the armature. The shaft 34 is connected with a centrifugal pump 40 having an impeller 42 secured to the lower end of the armature shaft 34 and having a hub extension 44 extending downward beyond the end of the outer casing .12. The centrifugal pump 40 also has a housing 48 which is rigidly connected with the upper part of the motor pump assembly by screws 50.

In normal operation the assembly 28 sits on annular surface 112. The motor pump assembly 28 hangs in the outer casing 12 by a support 52 when the motor pump assembly is lifted relative to the casing. This support includes a bolt 54 extending through the cover plate 16 and having limited axial sliding movement in the cover plate 16. A stuffing box 56 prevents the flow of fluid from the casing 12 through the opening in the cover plate '16 through which the bolt 54 extends.

In order to prevent the entire motor pump assembly 28 from rotating with respect to the outer casing 12, there are splines 60 on the outside of the pump housing 48 engaging complementary recesses in the end fitting 22. These splines leave the motor pump assembly free to move in a vertical direction with respect to the outer casing 12 so as to close the liquid passage to the casing when the pump is lifted by the support bolt 54.

The liquid passage through the apparatus includes an inlet 64 at the lower end of the pump hub extension 44. The liquid passage extends up between the hub extension 44 and the pump housing 48, the passage being indicated by the reference character 66. The passage extends through the pump impeller and then upwardly through an annular chamber 68 surrounding the motor 30. This annular chamber 68 opens through the upper end of the motor pump assembly 28 where it merges with a chamber 70 having openings 72 in the end of the motor housing.

When discharged from the openings 72 in the upper end of the motor housing, the liquid floods the entire interior of the outer casing 12 and it is discharged from the outer casing 12 through a pump discharge delivery line 76 at the top, or any other convenient location, on the housing assembly.

The apparatus has valve means for closing the liquid passage whenever the pump is lifted from the bottom of a container in which it has been used. In the construction shown, these valve means comprise a foot valve consisting of a bottom plate 80 having a center deflector 82 for deflecting horizontally moving liquid upwardly into the inlet 64 of the passage 66. Radially extending vanes 84 project upwardly from the plate 80 and there is an annular top plate 86 attached to the parts of the vanes 84 which are radially outward from the annular passage 66 leading into the pump. These vanes 84 serve as antivortex devices for the liquid being drawn into the pump; and a helical inducer 88 attached to the hub extension 44 assists in advancing the liquid upward to the impeller of the pump.

The bottom plate 80, vanes 84 and top plate 86 form an integral unit which is not connected with the rest of the assembly except by studs 90 which project upward from the plate 86 through openings in a flange 92 of the end fitting 22.

The studs 90 are angularly spaced around the axis of the assembly. Six such studs are shown in the drawing and these are merely representative of a plurality of studs.

At the upper end of each of the studs 90, there is a head 94 and a spring 96 is compressed between the head 94 and the top of the fiange 92. Thus the springs 96 give the valve means a bias toward closed position.

When the pump is lowered into a casing in a container, the pull on the support bolt 54 supports the motor pump assembly 28 until surface 110 rests on surface 112. During the last stages of downward movement housing 48 will force the plate 86 down and the motor pump assembly opens the casing valve. FIGURE 2 shows the relation of the parts with the casing valve closed and the pump just contacting plate 86.

Thus in FIGURE 2 the inlet 64 of the pump 40 is even with the flange 92, and the springs 96 are expanded, holding the studs 90 in their upward positions with the plate 86 approximately in contact with the bottom of the end fitting flange 92. The vanes 84 are in raised positions and enclosed by the lower part of the end fitting 22, and the plate 80 is in contact with the bottom of the end fitting 22 so that there is no clearance for passage of liquid between the end fitting 22 and the plate 80. The valve means are thus in closed position.

An inlet screen or frame 100 has openings 102 covered by a screen 104. The lower end of the frame 100 is in contact with the bottom 106 and all liquid flowing to the apparatus passes through the openings 102 and through the screens 104 which protect the pump from any foreign matter in the liquid.

As stated above the housing assembly or casing is supported in the tank and the pump motor assembly is then lowered into the casing. Complete lowering will force the casing valve open.

The downward movement of the motor pump assembly with respect to the outer casing 12 is limited by contact of a seat area 110 on the motor housing with an abutment surface 112 on the upper end of the fitting 22. The parts are preferably designed so that the contact of these

surfaces

110 and 112 with one another does not occur until the plate 80 is reasonably close to the bottom of the container on which the frame 100 of the screen is resting.

It is a feature of the invention that there are no obstructions under the plate 80. It is desirable to have the open clearance, through which liquid flows into the pump, as near the bottom of the container as possible so as to pump a larger percentage of the total contents from the container.

The motor pump assemblies of this invention are intended to be of substantial size and power so that they can be used for discharging the contents of ships. To provide adequate cooling for the submerged motors, the liquid pumped from the container is delivered through the passage 68 which forms a cooling jacket around the outside of the motor, but means are also provided for using the liquid to cool the bearing and the armature shaft of the motor. In the illustrated construction, this cooling is accomplished by by-passing some of the liquid back through the bearings and armature shaft. The bearings and shaft cooling is illustrated in FIGURE 1. Some of the liquid from the pump is withdrawn from the outer casing 12 through a fitting 116 at the upper righthand side of FIGURE 1. This liquid is passed through a filter 120 having both a fine mesh filter element and a magnetic separator which are at accessible locations and are easily cleanable. The filter mechanism is shown mounted topside but it could also be made part of the motor-pump assembly. After passing through the filter 120, the liquid is supplied through piping 122 to other piping 124 in the outer casing; and this other piping 124 leads back to the motor housing where the liquid is delivered to a passage 126 in the housing.

From this passage 126, liquid flows through the bearings 36 and through the armature shaft 34 in quantities sufficient to keep the bearings and shaft cool. The cooling liquid, after flowing through the lower motor bearing 36, is delivered to the pump impeller 42 and circulated back to the discharge passage with the other liquid from the pump.

The filter 120 has valves 130 for isolating it as necessary during cleaning and for shutting off the flow of liquid when the bearings are to be purged. There is a valve 132 connected with a compressed gas supply line 134 for introducing an inert gas, such as nitrogen, into the piping 122 and 124, to blow out all liquid from this piping and from the bearings 36 and the armature shaft 34 when the assembly is to be removed from a container after pumping out the liquid in the container. Because of the flammability of many liquefied gases with which this invention is used, it is desirable to remove the residual liquid from the apparatus before lifting it from the container. Means are also provided for purging the casing 12. This means is illustrated as an inert gas supply line and inert gas outlet line 142, the lines being supplied with the necessary valving. When the pump is raised a short distance the casing valve closes and it is then possible to purge the casing and motor-pump assembly of flammable fluids with inert gas. When the purging is completed the cover 16 may be removed and the pump lifted out of the casing and container without hazard. The pump may then be shifted to another tank.

The supply of power to the motor 30 is through a conductor cable 144 having a coil 146 which permits elogation and contraction to compensate for the relative movement of the motor pump assembly 28 in the outer casing 12 in the manner previously described.

The invention provides a simple and thoroughly automatic means for opening and closing the liquid passage into a submerged motor pump assembly when the assembly is placed in position for use or lifted for shifting to another location. Changes and modifications can be made in the illustrated embodiment without departing from the invention as defined in the claims.

What is claimed is:

1. Apparatus for removing liquid from a bulk container, including a housing assembly at least partly in said container, a delivery line connected to said housing assembly, a pump and a motor in the housing assembly, a support connected to the pump and motor, an inlet at a low part of the housing assembly, said inlet being part of a passage for liquid through the housing assembly to the pump, valve means commanding the passage and automatic means responsive to lifting of the pump and motor from the bottom of the assembly for moving the valve means into position to close the passage, said passage having an inlet that opens through the bottom of the housing assembly, the valve means being a plate which extends across the inlet and which has a deflector thereon for deflecting liquid upward into the inlet, spring means urging the plate toward the inlet to close the inlet, said spring means being located above the plate and above the clearance through which the liquid flows across the top of the plate to the inlet when the valve means are in open position, said spring means being operably connected with the housing assembly and the plate, said plate having anti-vortex vanes extending upward therefrom, and an annular element connected with the upper ends of the vanes and forming with the vanes a plurality of angularly related conduits leading to the inlet of said passage, a recess in the 'lower end of the housing assembly and into which the annular element of the vanes move when the plate moves toward the inlet of said passage to shut off flow of liquid into the inlet, rods extending upward from the annular element at angularly spaced locations around said element and through said recess, supporting means in the housing assembly above the recess and through which the rods extend and in which the rods are axially slidable, heads on the upper ends of the rods at some distance above said supporting means, the spring means including a helical spring on each of the rods compressed between the head of the rod and the supporting means through which the rod extends.

2. Apparatus for removing liquid from a bulk container, including a housing assembly at least partly in said container, a delivery line connected to said housing assembly, a pump and a motor in the housing assembly, .a support connected to the pump and motor, an inlet at a low part of the housing assembly, said inlet being part of a passage for liquid through the housing assembly to the pump, valve means commanding the passage, automatic means responsive to lifting of the pump and motor from the bottom of the assembly for moving the valve means into position to close the passage said motor having bearings and conduits through which some of the liquid pumped by the motor is circulated to the bearings for lubrication of the bearings, the housing assem- 6 bly including a casing into which the liquid is discharged by the pump, and a connection on a part of the housing assembly for connection with the delivery line, and gas conduits connecting with the casing for purging the casing, said conduits including one for purging liquid from the motor bearings.

3. The apparatus described in claim 2 characterized by the pump being a centrifugal pump for cryogenic liquids, said conduit for purging the bearings including an outlet through which liquid is withdrawn from the casing, a filter through which the liquid is pumped, a delivery line from the filter to the motor bearings, and a discharge outlet from the bearings into the casing.

4. A pumping system which comprises a pump and motor assembly, passage means connected to said pump and motor assem-bly for receiving the fluid pumped, conduit means connected to said passage means for circulating a part of the pumped fluid to bearing means in the pump and motor assembly, means to admit purging gas to said conduit means to purge the conduit means and bearing means of the fluid when desired.

5. The pumping system of claim 4 characterized by filter means in said conduit means.

6. The pumping system of claim .5 characterized by valve means in said conduit means to isola-te said filter means.

7. The pumping system of claim 4 in which the purging gas is nitrogen.

8. The pumping system of claim 4 in which the pump and motor assembly are submerged in the fluid being pumped.

References Cited UNITED STATES PATENTS 2,384,254 9/ 1945 Meredew. 2,978,150 4/1961 Doelcher 222-333 3,072,069 1/1963 Wittwer 103-218 3,369,715 2/1968 Carter 222-333 ROBERT M. WALKER, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,453 ,964 July 8, 1969 Stanley K. Hallworth It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 5, "bearing" should read bearings line 8, "bearings" second occurrence, should read bearing line 74, cancel "said pas"; line 75 cancel "sage having an inlet that opens through the bottom of". Colum 5, line 1, cancel "the housing assembly, same line 1, "being" should read including line 3, before "spring" insert said automatic means including line 8, "are" should read is line 13, before "a" insert and the plate line 14, before "6. insert means defining line 16, "move should read moves line 40, cancel "by the motor".

Signed and sealed this 14th day of April 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents