|Publication number||US3421554 A|
|Publication date||Jan 14, 1969|
|Filing date||Apr 1, 1966|
|Priority date||Apr 1, 1966|
|Also published as||DE1561999B1|
|Publication number||US 3421554 A, US 3421554A, US-A-3421554, US3421554 A, US3421554A|
|Inventors||Carter Clarence F|
|Original Assignee||Carter Eng Co|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (1), Referenced by (13), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
'Jan- 1969 c. F. CARTER METHOD AND APPARATUS FOR FILLING CONTAINERS Filed April 1, 1966 Sheet INVENTOR.
CLARENCE F. CARTER BY M,%M,WM0/m q ATTORNEYS Jan. 14, 1969 c, CAR ER A 3,421,554
METHOD AND APPARATUS FOR FILLING CONTAINERS Sheet 2 of 2 Filed April 1, 1966 VACUUM CONTAlNER 6 4 VIII 18 W INVENTOR.
n CLARENCE E CARTER BY 4194. DO,
ATTORNEYS United States Patent Int. Cl. B65b 31/02; B67c 3/16 8 ABSTRACT OF THE DISCLOSURE Method and apparatus for filling containers with powdered material by reducing the pressure in the container and utilizing the pressure differential to displace the powder from a hopper into the container. The container is evacuated through a port near the top of the container. The hopper valve is opened briefly and then closed to allow the vacuum to build up in the container while the valve is closed. After one or more filling shots, the rate at which air is drawn out of the container through the port 15 reduced, thereby causing material on the screens over the port to be dislodged before beginning another ser1es of filling shots. Also, the vacuum may be maintamed in the container at a high lever for a brief interval in order to shrink the powder that was previously deposited 1n the container.
This invention relates to a method and apparatus for filling containers with particulate material and, more particularly, to filling containers by means of a pressure differential between the hopper and the container.
Nonporous containers, such as cans, bottles and drums may be filled in accordance with conventional techniques by applying a vacuum to the interior of the container and then allowing particulate material to flow from a hopper into the container in response to the pressure differential acting on the material in the hopper. Generally, a filling head 1s applied to the mouth of the container and a hopper n which the particulate material is deposited commumcates with the container through a valve openin in the filling head. A fiuid passage in the filling head czmmunicates with the interior of the container. A vacuum pump exhausts air from the container through the passage to create a vacuum in the container. The resulting pressure diflierential draws particulate material through the valve opening and into the container. Usually a container is filled by repeatedly opening and closing the hopper valve to deposit an increment of material in the container while the valve is open and to build the vacuum back up in the container while the valve is closed. Although this apparatus operates satisfactorily for fillmg containers with most types of particulate material there is a tendency for the screens over the vacuum pas sage to become clogged while the container is being filled with material that has a very fine particle size. The vacuum pump continues to draw air out of the container as the fine particles pass from the hopper into the container and some of the particles are drawn toward the vacuum passage by the air currents. Also, the fine particles of material that are deposited in the bottom of the container may be so light that some of them are drawn toward the vacuum passage by the air currents in the container. Over a period of time, a coating of particles may be deposited on the screen covering the vacuum passage. This coating limits the level of vacuum that can be built up in the container.
In order to overcome the tendency for fine particulate material to coat the screens over the vacuum passage, it has been proposed to provide a pair of Passages and to "ice reverse periodically the flow of air across the screens during the filling cycle, as described in my earlier patent, No. 2,170,469. Although this screen clearing step overcomes the problem of coating the screens with most powdered materials, it has the disadvantage of requiring a certain amount of time during the filling cycle for circulating the air across the screens and thus the rate at which containers can be filled is relatively slow. Also, if the particles previously deposited in the container are very small, they may be stirred up by the air currents and render the screen clearing step ineffective.
Accordingly, it is an object of this invention to provide a method and apparatus for filling containers with fine, particulate material.
It is a further object of this invention to provide a method and apparatus for rapidly filling containers with fine, particulate material, by means of a pressure differential, without clogging the vacuum passages.
These objects are accomplished in accordance with a preferred embodiment of the invention by applying a vacuum to the interior of the container and then briefly opening the material supply valve to allow material to flow from the hopper into the container. When the supply valve is open, the pressure in the container rises and when the valve is closed, the vacuum builds up to a predetermined level again in the container. The portion of the filling cycle between the time when the supply valve first opens until it starts to open again is known as a shot. The buildup of the vacuum occurs as rapidly as possible in order to reduce to a minimum the filling time for the container. The periodic opening and closing of the supply valve in this manner, while continually withdrawing air from the container is repeated until the container is partially filled. This may require one or more shots.
The supply valve is again opened and closed to allow a charge of material to pass into the container, but the rate of flow of air out of the container through the vacuum line is substantially decreased, so that the vacuum builds up slowly in the container. Thus, the air currents are not strong enough to draw the particles against the screen. When the vacuum has reached a predetermined level, the rate of flow of air is adjusted to maintain the vacuum in the container at the predetermined level for a certain interval of time. The supply valve is again opened for the next shot during which material flows from the hopper into the container and the cycle may be repeated, as necessary, until the container is filled.
The apparatus for carrying out this method includes a valve arrangement for adjusting the rate of flow of air out of the container through the vacuum line in order to vary the rate of buildup of vacuum in the container and to maintain the vacuum at a selected level for a selected time interval.
This preferred embodiment is illustrated in the accompanying drawings in which:
FIG. 1 is a schematic view of the apparatus of this invention;
FIG. 2 is a cross sectional view of a filling head and container;
FIG. 3 is a cross sectional view of the filling head along the line 33 in FIG. 2;
FIG. 4 is a schematic view of the vacuum pump and valve for controlling the air flow from the container; and
FIG. 5 is a graph showing the changes in pressure in a container while it is being filled.
Referring to FIG. 1, a filling head 2 is applied to the mouth of a container 4. The container 4 is clamped between the filling head 2 and a movable platform 6. A hopper 8 on the filling head body 10 receives particulate material which is to be deposited in the container 4.
The filling head body 10 has a gasket 12 which cooperates with the mouth of the container 4 to form a seal between the container and the body 10. Particulate material flows from the hopper 8 into the container 4 through a central passage 14 in the filling head body 10. A valve 16 ismounted in the passage 14 to control the flow of material from the hopper 8. The valve 16 has a resilient sleeve 18 which is inflated by air under pressure to expand and close the passage 14. The construction and operation of the air-operated valve 16 is described in my Patent No. 2,687,145.
Arcuate recesses 20 are formed in the lower surface of the filling head body around-the passage 14. The recesses are covered by screens 22 which are secured in the filling head body 10. Passages 24 in the filling head body 10 communicate between the recesses 20 and the periphery of the body 10. The passages 24 are connected to conventional tubing 26, which is shown schematically in FIGS. 1, 2 and 3, by a threaded fitting 28. Another passage in the body 10 supplies air to the inflatable valve 16. Air is supplied through tubing 32 which is connected with the passage 30 by a conventional fitting 34 at the periphery of the body 10.
As shownin FIG. 1, air under pressure is supplied to the tubing 32 by a pump 34 and the flow of air through the tubing 32 is controlled by a valve 70. A vacuum pump 38 is connected to the tubing 26 and the rate of flow of air through the tubing is controlled by a valve 40. Of course, the pumps 34 and 38 may be a single pump with the tubing 26 connected to the vacuum side and the tubing 32 connected to the pressure side. The valve 40 is an adjustable valve that is operated by a control unit 42.
Referring to FIG. 4, the control unit 42 includes a fluid actuator 44 and a flow control system 46. The valve 40 has an inlet conduit 48 and an outlet conduit 50 which are connected to the filling head 2 and the vacuum pump 38, respectively, by the tubing 26. A valve seat 52 is provided in a partition 54 which separates the inlet and outlet conduits. A valve element 56 is supported on the end of a valve stem 58 which is mounted for reciprocating movement in a bearing 60. The opposite end of the valve stem 58 is connected to a piston 62 in the fluid actuator 44. The position of the valve element 56 relative to the seat 52 controls the rate of flow of air out of the container 4.
The control system 46 supplies air or other fluid to the actuator 44 to control the position of the piston 62. The control system 46 must be capable of moving the valve element 56 to a fully open position during the initial portion of the filling cycle. While the element 56 is being held open by the piston 62, the system 46 inflates the supplyvalve 16 at regular intervals for each shot during which material flows into the container and then the vacuum builds up again. After a predetermined number of shots, the system 46 closes the valve 56 to reduce the rate of flow through the valve 40 and thereby reduce the rate at which the vacuum is built up in the container 4. The vacuum is maintained in the container for a predetermined time interval before the supply valve is again opened. Then the valve element is displaced to a fully opened position to provide a higher flow rate through the valve 40 during the next shot.
A suitable system for controlling the supply valve 16 and vacuum valve 40 is shown in FIG. 4. Of course, other systems may be used for controlling these valves in the manner described above. The system 46 includes fluid conduits 64 and 66 which connect the pump 34 with opposite sides of the piston 62. The tubing 32 that supplies air to the inflatable valve 16 is also connected to the pump 34. A timer 68 controls the flow of air to the actuator 44 and to the valve 16. The timer is a conventional type of electrical timer that trips relays at preset time intervals. The relays in the timer are connected with solenoid operated valves for controlling flow through the conduits 64 and 66 and the tub-ing 32.
A solenoid valve 70 is operated by the timer 68 to open and close the valve 16 at predetermined intervals. A solenoid valve 72 in the conduit 64 controls flow to one side of the piston for displacing the valve element away from the seat 52. Another solenoid valve 74 in the conduit 66 controls flow to the opposite side of the piston 62. The valve 72 and 74 are three-way valves, which in one position allow air to escape from the valve when air is being supplied to the actuator 44 through the other valve. Thus, the unbalanced pressure in the actuator causes the piston 62 to be displaced in the desired direction.
The timer 68 is adjusted to close the valve 40 after a selected number of shots. This is accomplished by opening the valve 74 to supply air to the actuator 44 and allowing air to escape from the conduit 64 through the valve 72. Preferably, the valve 40 is closed at the same time that the valve 16 is inflated by operating the valve 70. In order to change the rate of build-up of vacuum in the container 4, a bypass conduit 76 is provided. The bypass conduit has a throttle valve 78. which may be adjusted to control the rate of flow of air through the conduit 64 to the actuator 44. Flow of air through the bypass conduit 76 is controlled by a solenoid valve 80. The timer 68 is set to open the valve immediately after the piston 62 has moved to close the valve 40.
The pressure conditions in the container 4 while the container is being filled in accordance with this invention are shown graphically in FIG. 5. At the point A on the graph, the valve 70 is open to inflate the supply valve 16. The valve 72 is open to supply air to the actuator 44 and the valve 74 exhausts air from the conduit 66. The valve 80 is closed and the throttle valve 78 is adjusted to produce the desired rate of movement of the valve element 56. As the first shot starts, the valve 70 is closed by the timer to open the supply valve 16 and allow powdered material to flow from the hopper 8 into the container 4. Since the interior of the container 4 is in communication with atmospheric pressure through the hopper 8, the vacuum in the container decreases as the material flows into the container. At the point B on the curve, the supply valve 16 is closed by means of the valve 70. The vacuum 40 remains open after the valve 16 closes and the vacuum rises rapidly to the point C on the curve. The first shot is then completed. A series of shots similar to the first shot may be provided.
At the point C, the su ply valve 16 is again opened by closing the valve 70, and the vacuum valve 40 remains open. The material flows from the hopper into the container as in the first shot. At the point marked D. on the curve, the supply valve 16 is closed by opening the valve 70 and the vacuum valve 40 is closed by moving the element 56 against the valve seat 52. This is accomplished by means of the timer 68 which opens the valve 74 and positions the valve 72 to exhaust air from the conduit 64. The pressure differential moves the piston 62 toward the valve seat 54 until the valve 40 is closed.
Immediately after the valve closes, the control valve 72 is closed by the timer 68 and the valve 74 is opened to the atmosphere. The valve 80 is also opened to direct air through the valve 78 to displace the element 56 away from the valve seat 52 at a sufliciently slow rate to prevent the powdered material in the container to be drawn up against the screens 22. The increase of vacuum in the container continues until the valve 40 is fully open, at about the point E on the curve in FIG. 5. Since the leakage of air into the container 4 is approximately constant when the supply valve 16 is closed, the level of vacuum in the container remains approximately constant. The time interval during which the vacuum remains constant, the interval between points E and F, is determined by the timer 68. At the point P, the next shot starts.
The time interval required for carrying out the delayed vacuum buildup depends primarily upon thesize of the container. A change in vacuum in the container from 10 inches of mercury to 24 inches of mercury for a five gallon container may require five to ten seconds, while a fifty-five gallon container may require up to fifty seconds.
This method produces better filling rates for fine materials, such as soft carbon black, paint pigments, light calcined magnesia, and aluminum powders.
One of the advantages of this invention is that containers may be filled rapidly with light particulate materials by rneans of a vacuum, without coating and clogging the vacuum outlet with particles of the material being deposited in the container. Another advantage of the delayed vacuum buildup of this invention is that the material deposited in the bottom of the container by preceding shots tends to become compacted by the gradually in-- creasing vacuum, so that a greater volume of material may be placed in the container.
While this invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.
1. A method of filling containers with particulate material comprising in sequence the steps of: withdrawing gas from the container at a first predetermined rate through a screened port to reduce the fluid pressure in the container, dispensing a quantity of the material into the container through a valve from a zone at higher pressure, closing the valve and withdrawing gas at a second predetermined rate from the container through said port, said second rate being lower than said first rate, whereby paricles of said material are dislodged from said screened port due to the lower rate of gas flow into said port during said last mentioned gas withdrawing step.
2. The method of claim 1 including mairtaining said container at a reduced substantially consant pressure for a predetermined time interval during said last mentioned gas withdrawing step.
3. The method of claim 1 wherein said first mentioned gas withdrawing step and said dispensing step are repeated in sequence prior to said last mentioned gas reducing step.
4. Apparatus for filling containers with fine particulate material comprising a hopper, filling head means, seal means on said filling head means for receiving a container and forming a fluid seal therebetween, an air discharge port on said filling head means, said port having a screen thereon, said filling head means including valve means for supplying material from said hopper to said container, passage means for conducting air through said port from a container positioned in engagement with said sealing means, means for drawing air away from said container through said port at a first predetermined rate, and means for changing the rate of flow of air through said port after a predetermined time interval.
5. The apparatus according to claim 4 wherein said flow rate changing means operates in phased relation with said supply valve means.
6. The apparatus according to claim 4 wherein said container is supported below said filling head means, whereby said material tends to fall toward the bottom of said container.
7. The apparatus according to claim 5 wherein said fiow raie changing means include-s a valve in said passage means, said valve having a first position and a second position, said valve first position providing air flow at said first predetermined rate and said valve second position providing air flow at a rate lower than said first predetermined rate, fluid means for displacing said valve from one of said posiions to the other, and timer means for operating said fluid means at predetermined time intervals, whereby said valve is initially in said first position and after a predetermined time interval is displaced to said second position, and after a second time interval is displaced back to said first position.
8. The apparatus according to claim 6, wherein said timer is operatively connected to said filling head valve means for coordinating opening and closing of said filling head valve means with said flow rate valve.
References Cited UNITED STATES PATENTS 2,642,215 6/1953 Carter l41286 X HOUSTON S. BELL, JR., Primary Examiner.
US. Cl. X.R. l4l59, 102, 286
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2642215 *||Apr 3, 1952||Jun 16, 1953||Carter Clarence F||Oscillating valve mechanism|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3683976 *||Feb 6, 1970||Aug 15, 1972||Applic Gaz Sa||Filling heads for liquid containers|
|US4185669 *||Jan 16, 1978||Jan 29, 1980||Alfa-Laval S.A.||Method and apparatus for filling a receptacle with powder|
|US4321922 *||Jan 21, 1980||Mar 30, 1982||Deaton David W||Medical receptacle with disposable liner assembly|
|US4379455 *||Sep 14, 1981||Apr 12, 1983||Deaton David W||Medical receptacle with disposable liner assembly|
|US4419093 *||Sep 14, 1981||Dec 6, 1983||American Hospital Supply Corporation||Method of receiving and disposing of fluids from the body|
|US4597420 *||Feb 7, 1985||Jul 1, 1986||At&T Technologies, Inc.||Techniques for multipoint dispensing of viscous material|
|US4624099 *||Apr 7, 1980||Nov 25, 1986||Mahaffy & Harder Engineering Co.||Packaging apparatus for making gas-filled packages from plastic film|
|US4967814 *||Jun 23, 1989||Nov 6, 1990||Westvaco Corporation||Apparatus for filling high pressure gas storage bottles with powdered activated carbon|
|US8113245 *||Jan 24, 2006||Feb 14, 2012||Commissariat A L'energie Atomique||Device for filling a container with at least one type of powder material|
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|EP2347959A1 *||Jan 18, 2011||Jul 27, 2011||OPTIMA filling and packaging machines GmbH||Method and device for filling|
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|U.S. Classification||141/7, 141/59, 141/286, 141/102|