US2975912A

US2975912A - Charging device

Info

Publication number: US2975912A
Application number: US677885A
Authority: US
Inventors: Stanley L Handforth
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-06-19
Filing date: 1946-06-19
Publication date: 1961-03-21
Anticipated expiration: 1978-03-21

Description

March 21, 1961 s. l.. HANDFORTH 2,975,912

CHARGING DEVICE Filed June 19, 1946 2 Sheets-Sheet 1 FIE. 1.

March 21, 1961 s. HANDFORTH 2,975,912

CHARGING DEVICE Filed Jun@ 19, 1946 2 Sheets-Sheet 2 INVENTOR.

Sn/e/ L. Hndforzb CHARGiNG DEVICE Stanley L. Handforth, Wilmington, Del., assigner to the United States of America as represented by the United States Atomic Energy Commission Filed .lune 19, 1946, Ser. No. 677,885

9 Claims. (Cl. 214-17) The present invention relates to apparatus for convey- `ing radioactive materials'into a vessel surrounded by massive barrier walls.

in the manufacture of plutonium by neutronic bombardment of natural uranium, a product is formed containing plutonium and radioactive by-products. The high radioactivity of the resulting material necessitates its maintenance and handling in vessels adequately shielded to protect personnel in the vicinity.

Since the radioactive materials emit gamma radiation which imparts radioactivity to `all materials of construction exposed to this radiation, it is necessary that handling equipment be capable of removal from the barricaded zone without necessitating the entry into the Zone of mechanics or laborers.

It is an object of the present invention to provide a charging apparatus `for introducing charges of radioactive material into a barric-aded tank or reactor. A further object is to provide such an apparatus which is operated entirely from the exterior of the barricaded zone. A further object of the invention is to provide such an apparatus which is 'readily accessible -for mechanical adjustment and repair. Still further objects of the invention will appear from the following description thereof and detailed illustration by a specific embodiment.

The invention contemplates a tank entirely surrounded and roofed by a massive radiation barrier which contines the affected Zone. Beneath this barrier `and below the level of the tank a channel extends into the barricaded zone. This channel is iilled with a liquid which impedes the passage of gamma radiation. In the top of the reaction tank'a charging hole Vis provided located in alignment with the channel. The massive barrier extends downward into the channel below the liquid level therein so as to form a liquid seal VWhere the channel passes under the barrier.

A conveyor comprising a pivoted bent aum is supported at one end by a pivot outside the barrier and above the channel so that the free end of the arm is movable' from a position below the liquid level in the channel outside the affected zone to a second position above and in proximity to the charging hole. In swinging from the rst position to the second position the arm passes through the liquid seal. A receptacle, such as `a bucket or cage, is pivotally fastened to the'free end of the arm so that the receptacle will remain in a vertical position during movement of the arm and so that it can be rotated from lan upright position to an inverted dumping position. Rotating means are provided outside the aiiected zone for controlling the motion of this receptacle.

Radioactive material is conveyed to the vicinity of the reaction tank by way of the channel and is temporarily stored outside the barricaded Zone under '-a suflicient depth of liquid in the channel to prevent danger to operators located above the channel. Radioactive material is conveniently stored in perforated containers `and may be conveyed along the channel by means of a monorail arent Figure 2 is a plan view of the same apparatus with gear cases removed to sow the primary gear trains. In both iigures the wall structure has been cut away to permit a complete showing of the apparatus.

In the drawing the numeral 1 designates Va reaction tank into which it is desired to charge radioactive material. Tank l is entirely surrounded by a massive concrete barrier wall 2, which contines the affected zone. Tank :1 is provided with a charging chute 3 which is closed by a hinged lid 4 shown in open position in the drawing.A

This lid projects substantially `beyond the edge of the charging chute and is arranged so as to settle by gravity into its normal securely closed position. A three-sided hood 3a is provided around the chute. In Figure l the near side has been removed to permit a complete` view of the lid 4.

Extending beneath wall 2 and in line with chute 3 is la channel 5, which is normally filled with water to a level above the bottom edge of wall 2 so as to form a liquid seal. Located directly over channel 5 and in line with chute 3 is a monorail 6 for conveying radioactive material to loading position A, indicated by broken lines. The radioactive material may be transported in perforatedY containers 7.

Mounted outside the affected zone and supported on bearings 8 and 9 is a shaft 1t) which carries a U-shape'd arm or elbow 1l. The curvature of this elbow is such that its free end can move between dumping position B,- illustrated in solid lines, and loading position A, without collision with wall '2. The slight slope of wall 2 above channel 5 permits relatively close positioning of chute 3` With respect to the wall. The weight of Varm 1.1 is balanced on shaft "16 by a counterweight 12. Rotation fof shaft 10 and corresponding displacement of arm'll are effected through gears i3 and I14 and power unit 1S comprising a motor and suitable reduction gears. Gears 13 and 14 are housed in a case le. A pointer 17 ismounted on shaft lil and indicia on gear case 16 show the position of arm 11 so that the operator can readily determine when this arm has reached its loading station :or its dumping station.

At its free end arm 1l carries a shaft Z0 to which is aixed a bucket 2l, counter-weight 22, and sprocket 23. ln Figure 2, lidl 4 has been cut 'away to show the bucket structure. The rotation of shaft Ztl is controlled by a chain and sprocket linkage comprising a continuous chain 24 operating on sprocket 23 and following the arm` l1 back to sprocket 25. Sprocket 25 is rigidly mounted on a tubular shaft 26 mounted on shaft lil "and is controlled through a suitable gear train 27 by operating hand-crank 28. The gear train 27 also drives a pointer on an indicator 29 showing the positionv of bucket 211. Chain 24 is held in position on arm 11 by idlersV 30, 31, 32 and 33. Bucket 2l is provided with a latch 34 for holding container 7 in position. f An empty container '7 may be removed from the bucket 21 by raising latch 34 and merely lifting the container from the larger bucket by means of a pole hook. Latch` 34 in the form illustrated is designed for retention iii latching position by gravity. When a'small container is inserted in the larger bucket, 4this latch automatically permits the smaller container to pass and then drops Patented Mar. 2l, 1961 d by gravity into locking position. For removing the container, it is necessary to raise the handle of the latch by means of a pole hook or similar device. While the latch can be designed readily for gravity operation for both locking and unlocking, it is desirable to determine definitely that it is in latching position before transferring it from the loading station to the dumping station in order. to avoid the possibility that a container 7 may be lost into chute 3 when bucket 21 is inverted. The buckets 7 and 2l Imay be provided with perforations to permit water to drain from the buckets as they rise above the water in the channel. This is not necessary to the successful operation of the :charging device, however, and solid buckets may be used when introduction ot water into reaction tank 1 is not objectionable.

In order to avoid travel of arm 11 and bucket 2l beyond the desired loading and dumping positions, stoppins 35 and4 36 of conventional type may be employed. As a safety precaution, limit switches of conventional design may be provided to prevent operation of power unit 145 when bucket 2l is not in vertical position. Like wise conventional limit switches may be used in place of or in addition to manual control for limiting the movement of arm 11.

The operation of the apparatus is as follows.

By means of the power unit 15, arm l1 is brought to loading station position A. By means of monos-ail 6 a charge of radioactive material in container '7 is brought forward along channel until it is directly over bucket 21 and is then lowered into place in the bucket. Latch 34 falls into place by gravity. Unit l5 is then operated .to swing arm 11 toward the dumping station position B. When arm l1 reaches the dumping station B as indicated by pointer 17, the arm is stopped. During this movement the sprocket 2S remains stationary so that bucket 21 remains vertical. Hand-crank 28 is now rotated to turn 4bucket 21 'clockwise to the dumping position shown in broken lines in Figure l.

As arm 11 swings from loading station A to dumping station B, it contacts the lid 4 and raises this lid to uncover chute 3. Uponrotation of bucket 2l the lid is opene-d still more Widely so that it permits material in the bucket to flow through chute 3 into tank i. Latch 34 holds container 7 in bucket 2.1 during the discharging operation.

`After the-bucket 21 is discharged, hand-crank 2.8 is Irotated to restore the bucket to vertical position as shown by indicator 29 and the power unit 15 is actuated to rcturn the arm and bucket to loading station A. Cover 4 -returns to closed position by gravity.

By continuingr the movement of arm 11 beyond loadingA station A, it is possible to raise bucket 2 above the water level outside of Wall 2. This is illustrated by broken lines at C. The arm may be Imoved to this position whenever it is desired to inspect the bucket or the end of the arm or to make repairs on this equipment.

It will be understood that I intend to include variations andvmodifcations of the-invention and that the preceding example is illustrative only and in no wise to be construed as limitative upon the invention, the scope of which is defined in the appended claims, wherein l claim:

l. An apparatus for handling radio-active material, comprising a liquidcontaining channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and confining an aected zone and extending into the channel and below the liquid leveltherein so as to form a liquid seal, a bent arm pivoted outside the affected zone and having a free end movable between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a receptacle mounted. on the free end of said bent arm.

adapted to rotate between an upright position and a dumping position, and means controllable externally of d 4said affected zone for rotating said receptacle and said bent arms independently.

2. An apparatus for handling radioactive material, comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and confining an affected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm pivoted outside the aifected zone and having a free end movable between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a receptacle mounted on the free end of said bent arm and motatable between an upright position and a dumping position, and means located externally of said affected zone for rotating said receptacle between said two positions.

3. An apparatus for handling radioactive material, Comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and confining an affected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm pivoted outside the affected zone and having a free end movable between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a receptacle mounted on lche free end of said bent arm and yrotatable between an upright position and a dumping position, means for maintaining the receptacle vertical during movement 4of the arm between said two positions, andI means located externally of said affected zone for rotating saidy receptacle between said two posi-- tions.

4.l An apparatus for handling radioactive material.l comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall Surrounding said tank and coniiniugV an affected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm pivoted outside the affected zone andhaving a free end movable. between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a receptacle mounted on the free end of said bent arm and rotatable between an upright position and a dumping position, means for maintaining the receptacle vertical during movement of the arm between said two positions, means located externally of said affected zone for rotating said receptacle between said two positions, and a latch on the receptacle arranged for retaining a container upon inversion of the receptacle.

5. An apparatus for handling radioactive material, comprising a liquid-containing channel for submerged storage of 'radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surounding said tank and conning an affected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm. pivoted outside the affected zone and having afree end movable between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, said free end being provided with an axle having a receptacle and sprocket fixed thereto, a crank located externally of said affected zone for actuating said chain and thereby rotating said sprocket and receptacle between two positions, and means located externally of said affected zone for indicating the position of said receptacle.

6. An apparatus for handling radioactive material, comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel :and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and conining an affected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm pivoted outside the atected zone and having a free end movable between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a receptacle mounted on the free end of said bent arm and rotatable between an upright position and a dumping position, means located externally of said affected zone for rotating said receptacle between said two positions, visual indicators located externally of said affected zone. for indicating the position of the free end of said bent arm and the angular position of said receptacle.

7. An apparatus for handling radioactive material, comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and conining an aiected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm pivoted outside the attected zone and having a free end movable between a position below the liquid level in the channel outside the atected zone and a second position proximate to said charging hole, a receptacle rotatably mounted on the free end of said arm, a sprocket rigidly mounted with respect to said receptacle, a second sprocket located outside of said affected zone and arranged to remain stationary during rotation of said arm, a chain connecting the two sprockets, means located externally of said affected zone for rotating the second-mentioned sprocket, and visual indicators located outside the aiected zone for indicating the position of said bent arm and the angular position of said receptacle.

8. An apparatus for handling radioactive material, comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and conning an affected zone and extending into the channel and below the liquid level therein so as to forrn a liquid seal, a bent arm pivoted outside the affected zone and having a free end movable between a position below the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a bucket rotatably mounted on the free end of said arm, a sprocket rigidly mounted with respect to said bucket, a second sprocket located outside the aiected zone and arranged to remain stationary during rotation of said arm, a chain connecting the two sprockets, means located externally of said alected zone for rotating the secondrnentioned sprocket, visual indicators located outside the `aiected zone for indicating the position of said bent arm and the angular position of said bucket, and a latch on said bucket arranged for retaining a container upon inversion of the bucket.

9. An apparatus for handling radioactive material, comprising a liquid-containing channel for submerged storage of radioactive material, a tank to contain the radioactive material located near the channel and having a charging hole located at a level above the liquid level in the channel, a barrier wall surrounding said tank and confining an aiected zone and extending into the channel and below the liquid level therein so as to form a liquid seal, a bent arm pivoted outside the atected zone and having a free end movable between a position lelow the liquid level in the channel outside the affected zone and a second position proximate to said charging hole, a bucket rotatably mounted on the free end of said arm, a sprocket rigidly mounted with respect to said bucket, a second sprocket located outside the alected zone and arranged to remain stationary during rotation of said arm, a chain connecting the two sprockets, means located externally of said affected zone for rotating the second-mentioned sprocket, visual indicators located outside the affected zone for indicating the position of said bent arm andthe angular position of s-aid bucket, a latch on said bucket arranged for retaining a container upon inversion of the bucket, a closure for the tank charging hole having a projection engageable by engaging means on said arm to remove the closure to a position exposing said charging hole, and means for returning the closure upon disengagement of said projection.

Maring Nov. 6, 1934 Crosby May 20, 1947