GB2045193A - Conveying articles along channels by air flow - Google Patents

Abstract

An air conveyor system for the transfer of containers comprises a pair of spaced side walls 44A, 46A joined to a top wall 64, to form an inverted channel through which the containers can roll, a row of airjets 78, 80 in each side wall connected to receive pressurised air and direct it at an angle on to the opposite ends of the containers, the air from the jets, and additional air if necessary flowing into the space above the containers and between the containers to an exhaust below the containers, a positive air pressure being maintained above and between the containers to maintain the containers separated from one another while being transported. The containers rest on guide rails 32, 34 beneath the channel. <IMAGE>

Description

SPECIFICATION Improvements in and relating to air conveyor systems This invention relates to air conveyors for the transfer of containers from one location to another.

One of the disadvantages of existing conveyors is that where a high volume of articles is to be moved, the articles, packages, cans and the like are subjected to damage caused by the articles colliding with one another due to the high velocities the articles reach.

The present invention seeks at least to reduce and preferably to eliminate such damage.

According to the present invention there is provided a method of conveying containers and a conveyor system for containers, both as defined in the claims appended hereto.

The invention will now be described in detail, by way of example with reference to the accompanying drawings in which Figure 1 is a view in elevation, with portions broken away to conserve space, of a length of an air conveyor according to the invention; Figure 2 is a top plan view of the air conveyor with portions broken away to conserve space; Figure 3 is a cross sectional view in elevation of Figure 2 along line 3-3 to an enlarged scale; Figure 4 is a cross sectional view in elevation along line 4-4 of Figure 3; Figure 5 is a cross sectional plan view along line 5-5 of Figure 3; Figure 6 is a diagrammatic illustration of a supplemental air supply arrangement, and Figure 7 is a diagrammatic illustration of the conveyor of this invention being used to merge several different sources of containers with one feed line.

Referring to Figures 1 and 2 of the drawings, the conveyor is shown as essentially a horizontally positioned U-shaped channel 10 although the channel may be inclined above the horizontal and would not ordinarily be used in a vertical position but could be. The inlet end 12 of the conveyor 10 is fed cans 14 from an elevator output. The cans may be gravity fed from the elevator output via upper and lower guide rails shown as 16, 18 and 20,22 supported in spaced relation to either end of the cans 14 as by spacing elements 24 and 26.

Referring more particularly to Figure 3, the guide rails 16, 18 and 20, 22 connect respectively with guides 28,30 and 32,34. The guides and channel are seen to be supported by means of elongated plenum chambers 36 and 38 positioned to either side of the guides and having sides 44 and 46 secured together in spaced relation throughout the length thereof by a plurality of spacer elements 40 and 42 secured to sides 44 and 46 of respective plenum chambers 36 and 38 by means of bolts 48 and the like. The sides 44 and 46 of the plenum chambers are also seen to be common to the U-shaped channel or chamber 50 of the conveyor and are each seen to form a side thereof identified as 44A and 46A respectively.The lower guides 32 and 34 are secured to sides 44A and 46A by means of a stud and nut 52 and 54 while upper guides 28 and 30 are secured thereto by means of a stud and nut 56 and 58. L-shaped brackets 60 and 62 are supported on the studs and nut 56 and 58 and in turn support the top 64 of the channel between guides 28 and 30 in closed relation. The top is supported on the brackets by means of bolts and nuts 66 and 68 which provide for vertical adjustmentand positioning of the top with respect to the guides and the can 14.

A plurality of holes 70 and 72 are provided in the sides 44A and 46A of the U-shaped channel in spaced serial relation essentially parallel to the longitudinal dimension. Jet boards 74 and 76 are secured to sides 44A and 46A by suitable means such as bolts and the like and positioned to register with holes 70 and 72. The jet boards are provided with jet openings 78 and 80 therethrough to coincide with holes 70 and 72. The jet openings are preferably located above the centerline of the container and normally positioned at an angle to direct air passing therethrough from the plenum chambers 36 and 38 to chamber or channel 50 in a downstream direction. The angle of the jets for reference sake will be referred to as the angular deviation from a line normal to the surface of the jet board, with 0 being at right angles thereto.

Air is introduced into the plenum chambers 36 and 38 via conduits 82 and 84 connected to a suitable blower or blowers, not shown. Air at a positive static pressure is forced through the plenum chambers and the connecting jet openings into the U-shaped conveyor channel 50. The angles of the jet openings may be uniform throughout the length of the conveyor or they may be selectively of varied angles to provide a desired result. In transporting a 12 fluid ounce aluminum can horizontally, the angle ofthejet openings are found to be preferably from about 80two about 1 from the normal although angles from 5" to 50 may find utility with other and various cans and containers.The containers are preferably of cylindrical shape although variations therefrom may be made with suitable changes in the conveyor.

The jets are positioned in a vertical direction in the jet boards such as to be, with the cans at rest, slightly above the centerline of the cans. The air being introduced into the U-shaped channel from each plenum 36 and 38 through the jet openings 78 and 80 is of such velocity and volume to provide lift to the cans such that they barely ride on or slightly above the guides 32 and 34 and a positive pressure with respect to and greater than the ambient atmosphere is produced and maintained in the channel space 86 above and between the cans.For a 12 ounce aluminum can, i.e. an aluminum can which will hold 12 fluid ounces, jet angles are preferably about 8 to about 11 from the normal to the longitudinal dimension of the U-shaped channel and with a static pressure in the plenum chambers 36 and 38 of from about 1.0 inches of water to about 3.0 inches of water and the jet openings 78 and 80 should preferably be about 1/4 inch diameter up to about 3/8 inch with an intermediate preferred range of from about 7/32 inch to about 11/32 inch but may be about 1/8 inch up to about 3/4 inch for conveying other and various cans and containers. For jet openings 1/4 inch or larger, the velocity of air issuing from a jet is not increased by increasing the size of the jet opening but the volume of air (CFM) may be increased and the attendant energy.

Two forces are utilized to produce the desired end result of transporting containers along the horizontal while maintaning a spacing therebetween and yet provide for maximum throughput or storage of containers while avoiding surges during transport. Aforce is applied to the cans by the airjets impinging on the ends of the cans and as well a force is applied by the very volume (CFM) of air introduced into the channel. These forces need to be balanced for best operation of the conveyor. If the forces applied to the containers by the velocity transport component of the air jets and the volume transport component is excessive compared to the volume (CFM) pressure component, the cans will close up resulting in unwanted can-to-can contact. The pressure above and between the cans must be established and maintained greater than ambient pressure.

This is accomplished by selection of the appropriate jet angle, jet size and static pressure of the air supply for a particular container. Generally the greater the angle that the jet opening assumes with respect to a line normal to the longitudinal dimension of the U-shaped channel, the greater the volume (CFM) that is required to maintain a greater than ambient pressure in the space 86 between the containers and the top 64 of the channel. Where the volume of air introduced into space 86 is not sufficient to keep the containers separated, a supplemental volume of air may be introduced into the space 86 as by means of another plenum chamber 88 with an opening or openings 90 in top 64 along the length thereof, see Figure 6.

A fairly close spacing must be maintained between the top 64, sides 44A, 46A and the can 14, being preferably not greater than about 1/8 inch for a 12 ounch aluminum can. A spacing of as much as one quarter of an inch while not the preferred, may be satisfactory in certain applications.

As indicated above, air jet angles can be used up to as great as about 50 ; however, this will require a higher volume of air either by using larger jet diameters or by using supplemental air introduced between the cans 14 and the top 64 to keep the cans separated in transport. If the force applied to the cans by the jet transport vector is greater than the pressure between the cans, the cans will close up.

The jet angle, size, and static pressure in the plenum are chosen to provide substantially uniform pressure throughout the can train. By using air jets at different angles and sizes along the can train, selected variations of pressure can be selectively provided.

As will be explained later in greater detail, the angle of the jet openings may be variable or may be different in difficult sections of the conveyor for the purposes to be explained. Such variation will permit the transport of differing number of cans per foot and thus will allow merging cans from one source with cans from a different source into one train.

Reference is now made to the tables wherein data is presented of the several variables that have been made in the method and apparatus of this invention illustrating, and not by way of limitation, examples of the practice of the invention. All of the data was recorded in the transport of a 12 ounce aluminum can and it will be obvious to one skilled in the art that certain changes will need to be made where other and different size and weighted cans or containers are conveyed in accordance with the invention.

Tables Vl through IX, for example, show data resulting from the use of a jet angle of 9" from normal with jet sizes ranging from 7/32 inch to 5/16 inch in diameter. For example in Table IX, the use of a 5/16 inch diameter jet at an angle of 9" provided the best operation with an average cubic feet per minute of air per jet of 1.85 CFM providing an average jet vector transport velocity of 555 FPM at a static pressure of 1 inch water at the open end of the cans and 1.3 inch water at the closed end.The static pressure in the top under dynamic operating conditions between the cans was .05 inch water and between the top and a can .14 inch water to provide a delivery of 950 cans per minute with a speed of 216 feet per minute for the can train while the maximum attainable speed of a single can was 266 FPM, i.e. Table IX, item C, shows 950 CPM Cc 4.4 CPF, gives 216 FPM as the speed of the can train while the speed of a single can is 266 FPM under the same conditions. It is an important aspect of the present invention that the single can speed may be attained and maintained over great distances without the usual expected increases in speed. The conveyor provides graduated speed control, either an increase, or decrease. The speed of a single can may be selected for the desired recovery time of the can train, see Table XVIII.Thus, the conveyor provides means for controlling and regulating the gentleness in one can overtaking another while still maintaining the capability of moving the can train at the desired CPM production rate. With the conveyor of this invention the cans can be conveyed in mass, as a continuous train or on an intermittent basis with the desired gentleness for the article being conveyed. The conveyor may be completely emptied of cans and when the flow is released, the conveyor will fill at the single can per foot rate and then resume the desired can train production rate. It is important to note that the static pressure in the plenum adjusts for cans being conveyed. The cans can be stopped completely in the conveyor without adverse effects and because there is a complete absence of moving belts, ropes, cables to convey the cans, burnishing, marking and the like thereof will not occur. The safety of the operation is also greatly enhanced. With the constant pressure on the cans, the conveyor may be started up at full production rate, unlike mechanical conveyors which have to be brought up to speed gradually. The noise levels are vey substantially reduced because of the separation of the cans with air such that damage to cans is eliminated.

NOTE: Tables I through XII are based upon using a 2.625 inch can diameter with 4.4 cans per linearfoot TABLE I Can Train Avg. SP SP Jet Jet Jet Static Pr. CPM or Column Single Can Avg. CPM Avg.Vel Vector BTN AT Dia. Degree Centers O.E. C.E. Rate Speed FPH Speed FPM Per Jet Per Jet Vel Can Can Remarks 7/32 8 1" 1.0 1.4 400 91 142 .96 3723 517 .05 .14 poor 7/32 8 1" 1.2 1.6 500 114 130 1.04 4022 559 .02 .07 poor 7/32 8 1" 1.4 1.8 800 182 176 1.11 4301 597 .05 .13 fair 7/32 8 1" 1.6 2.0 750 170 181 1.18 4563 634 .05 .13 fair TABLE II 1/4 8 1" .9 1.3 550 125 120 1.21 3561 494 .04 .11 poor 1/4 8 1" 1.0 1.5 525 119 153 1.26 3723 517 .05 .11 fair 1/4 8 1" 1.2 1.7 575 131 162 1.36 4022 559 .05 .12 fair 1/4 8 1" 1.4 2.0 725 165 203 1.50 4452 616 .05 .12 fair TABLE III Can Train Avg. SP SP Jet Jet Jet Static Pr. CPM or Column Single Can Avg. CPM Avg.Vel. Vector BTM AT Dia.Degree Centers O.E. C.E. Rate Speed FPM Speed FPM Per Jet Per Jet Vel Can Can Remarks 17/64 8 1" 1.0 1.4 975 222 187A 1.41 3723 517 .06 .12 good 17/64 8 1" 1.2 1.6 975 222 206 1.52 4022 557 .06 .12 good 17/64 8 1" 1.4 1.8 975 222 226A 1.63 4301 597 .06 .15 good 17/64 8 1" 1.6 2.0 1075 244 285 1.73 4563 634 .06 .15 fair TABLE IV 9/32 8 1" .9 1;;2 850 193 230B 1.46 3400 472 .07 .10 very good 9/32 8 1" 1.1 1.5 875 199 230 1.66 3873 538 .07 .10 very good 9/32 8 1" 1.4 1.7 950 216 292 1.79 4161 578 .10 .16 good 9/32 8 1" 1.6 1.9 975 222 333A 1.90 4432 616 .10 .16 good TABLE V 19/64 8 1" .9 1.2 650 148 214 1.63 3400 472 .05 .10 good 19/64 8 1" 1.1 1.4 750 170 226 1.78 3723 517 .05 .10 good 19/64 8 1" 1.3 1.6 825 188 285 1.93 4022 559 .05 .11 good 19/64 8 1" 1.5 1.8 900 204 285 2.06 4301 594 .05 .11 fair TABLE VI 7/32 9 1" 1.0 1.3 -0- .96 3723 580 poor 7/32 9 1" 1.2 1.7 675 153 218 1.04 4022 627 poor 7/32 9 1" 1.4 2.0 850 193 255B 1.15 4432 691 fair 7/32 9 1" 1.7 2.2 875 199 307 1.21 4685 730 fair TABLE VII Can Train Avg. SP SP Jet Jet Jet Static Pr. CPM or Column Single Can Avg. CPM Avg. Vel. Vector BTM AT Dia. Degree Centers O.E. C.E.Rate Speed FPM Speed FPM Per Jet Per Jet Vel Can Can Remarks 1/4 9 1" .9 1.2 725 165 222 1.21 3561 555 fair 1/4 9 1" 1.1 1.4 775 176 266 1.26 3723 580 .06 .10 fair 1/4 9 1" 1.3 1.6 825 188 266 1.36 4022 627 .07 .10 good 1/4 9 1" 1.5 1.8 850 193 315B 1.46 4301 670 .05 .15 fair TABLE VIII 9/32 9 1" .8 1.1 825 188 230 1.38 3227 503 .03 .10 fair 9/32 9 1" 1.0 1.3 975 222 285A 1.53 3561 555 .06 .11 good 9/32 9 1" 1.2 1.5 1025 233 285 1.72 4022 627 .06 .14 good 9/32 9 1" 1.4 1.7 1100 250 342 1.84 4301 670 .10 .15 very good TABLE IX 5/16 9 1" .8 1.1 850 193 226B 1.67 3227 503 .05 .10 fair 5/16 9 1" 1.0 1.3 950 216 266C 1.85 3561 555 .05 .14 very good 5/16 9 1" 1.2 1.5 1075 244 324 2.09 4022 627 .08 .14 good 5/16 9 1" 1.4 1.7 1100 250 428 2.23 4301 670 .07 .14 fair TABLE X 7/32 10 1" 1.0 1.3 900 204 230 .96 3723 647 .02 .10 fair 7/32 10 1" 1.1 1.5 700 159 285 1.00 3872 673 .05 .10 fair 7/32 10 1" 1.3 1.7 800 182 260 1.08 4161 724 .05 .15 poor 7/32 10 1" 1.5 1.9 can pack too tight to .05 .15 poor allow separation to operate TABLE XI Can Train Avg. SP SP Jet Jet Jet Static Pr. CPM or Column Single Can Avg. CPM Avg.Vel. Vector BTM AT Dia. Degree Centers O.E. C.E. Rate Speed FPM Speed FPM Per Jet Per Jet Vel Can Can Remarks 1/4 10 1" 1.1 1.5 750 170 244 1.31 3872 673 .04 .10 poor 1/4 10 1" 1.3 1.7 825 188 272 1.41 4161 724 .09 .15 fair 1/4 10 1" 1.5 1.9 875 199 292 1.50 4432 771 .07 .14 fair 1/4 10 1" 1.7 2.2 875 199 333 1.59 4685 815 .05 .14 fair TABLE XII 9/32 10 1" 1.0 1.3 825 188 240 1.60 3723 647 .02 .09 Fair 9/32 10 1" 1.2 1.5 900 204 300 1.72 4022 699 .03 .09 Fair 9/32 10 1" 1.4 1.7 925 210 324 1.84 4301 748 .05 .15 Fair 9/32 10 1" 1.6 1.9 1000 227 363 1.96 4563 793 .05 .14 Fair TABLE XIII Can Train Avg.SP SP Jet Jet Jet Static Pr. CPM or Column Single Can Avg. CPM Avg.Vel. Vector BTH AT Dia. Degree Centers O.E. C.E. Rate Speed FPM Speed FPM Per Jet Pet Jet Vel Can Can Remarks 5/16 10 1" 1.0 1.3 775 176 272 1.93 3723 647 .05 .10 very good 5/16 10 1" 1.2 1.5 925 210 315 2.09 4022 699 .05 .11 very good 5/16 10 1" 1.4 1.7 950 216 352 2.23 4301 748 .05 .12 good 5/16 10 1" 1.6 1.9 950 216 428 2.37 4563 793 .05 .12 good TABLE XIV 11/32 10 1" .9 1.2 975 222 285A 2.17 3400 591 .09 .14 good 11/32 10 1" 1.1 1.4 1025 233 292 2.38 3723 647 .10 .15 better 11/32 10 1" 1.3 1.6 1100 250 342 2.66 4161 724 .10 .16 best 11/32 10 1" 1.5 1.6 1150 261 352 2.75 4301 748 .10 .16 fair TABLE XV Can Train Avg. SP SP Jet Jet Jet Static Pr. CPM or Column Single Can Avg. CPM Avg. Vel Vector BTN AT Dia. Degree Centers O.E. C.E.Rate Speed FPM Speed FPM Per Jet Per Jet Vel Can Can Remarks 5/16 11 1" 1.0 1.2 750 170 307 1.85 3561 680 .05 .15 poor 5/16 11 1" 1.2 1.4 900 204 342 2.01 3872 739 .05 .16 poor 5/16 11 1" 1.4 1.6 900 204 352 2.16 4161 794 .05 .15 poor 5/16 11 1" 1.6 1.8 975 222 413A 2.30 4432 846 .10 .16 poor TABLE XVI 11/32 11 1" .9 1.1 825 188 260 2.17 3400 649 .05 .15 fair 11/32 11 1" 1.1 1.3 875 199 315 2.38 3723 711 .05 .16 fair 11/32 11 1" 1.3 1.5 1075 244 352 2.57 4022 760 .05 .10 good 11/32 11 1" 1.5 1.7 1075 244 375 2.75 4301 821 .05 .11 good TABLE XVII Can Train Avg. SP SP Jet Jet Jet Static Pr. CPM or Column Single can Avg. CPM Avg. Vel. Vector BTN AT Dia. Degree Centers O.E. C.E.Rate Speed FPM Speed FPM Per Jet Per Jet Vel Can Can Remarks 3/8 11 1" .9 1.1 1100 250 342 2.61 3400 649 .10 .20 good 3/8 11 1" 1.1 1.4 1200 273 363 2.86 3723 711 .10 .20 good 3/8 11 1" 1.3 1.6 1250 284 400 3.09 4022 768 .10 .20 very good 3/8 11 1" 1.5 1.8 1250 284 428 3.31 4301 821 .15 .20 fair TABLE XVIII Cans per Minute and Train Speed vs. Single Can Speed Data Train Single Table CPM FPM FPM No.Item 975 222 187 lil A 975 222 206 Ill A 975 222 226 lil A 975 222 333 IV A 975 222 285 VIII A 975 222 285 XIV A 975 222 413 XV A 850 193 230 IV B 850 193 226 IX B 850 193 255 VI B 850 193 315 VII B TABLE XIX Space Space Occupied Between Stage CPM FPM CPF by Can-lnch Cans-lnch 1 140 488 2.0 5.25 6-3/4 2 280 390 2.5 6.56 2-3/4 3 420 325 3.0 7.87 2 4 560 279 3.5 9.18 15/16 5 700 244 4.0 10.5 1/2 6 840 232 4.2 11.02 1/4 7 980 222 4.4 11.55 7/64 Another use of the conveyor of the present invention will now be illustrated.Where a large number of cans or containers are moved from a mass storage or from several sources to be fed in a single file, an Air Single Filer apparatus can be used such as that covered in applicant's copending application Serial No.869,371, filed January 13, 1978, for AIR OPERATED CONVEYOR APPARATUS. As illustrated diagrammatically in Figure 7, a series of Air Single Filer conveyors 98A and 98B are serially connected and each conveyor is receiving, for example, 140 cans per minute to be merged together and provide a feed of 140n cans per minute from the last conveyor where n is the number of Air Single Filers or can streams to be merged. The first Air Single Filer 98A is fed 140 cans per minute and delivers 140 cans per minute to a conveyor 10A of this invention.The conveyor 10A is provided with jet opening sizes and angles and operating conditions to provide approximately 2 cans per foot with each can travelling at about 488 feet per minute, Table XIX. The output from conveyor 1 OA is merged with the throughput of another Air Single Filer 98B with an infeed of about 140 cans per minute and delivers 280 cans per minute to conveyor 10B. The conveyor 10B is provided with jet opening sizes, angle and operating conditions to provide about 2-1/2 cans per foot travelling at 390 feet per minute. The output from conveyor 1 OB is merged with the throughput of another Air Single Filer 98C, not shown, having an infeed of about 140 cans per minute and delivers 420 cans per minute to conveyor 10C, not shown.The conveyor 1 0C is provided with jet opening sizes, angles and operating conditions to provide about 3 cans per foot travelling at 325 feet per minute. The output from conveyor 1 0C is merged with the throughput of still another Air Single Filer 98D, not shown, having an infeed of about 140 cans per minute and delivers 560 cans per minute at approximately 279 feet per minute. Thus, it is seen that the conveyor of this invention can be tailored by selection of jet opening size, angle and operating conditions to perform merging operations as well as accumulator operations between other pieces of equipment. The positive pressure between the cans in each section 10A-10B and the like will be uniform throughout the length of each section but may be different from section to section. Table XIX sets forth the geometry of the conveyor system referred to above using cans that are 2.625 inches in diameter. The Air Single Filer 98A and 98B is shown as a first 2 foot section 1 00A and 1 00B with a portion 1 102A and 1 02B of the side walls perforated, shown dotted, for container control with jets at an angle of 30 and a depth to accommodate 3 container diameters plus 3/4 inch. The second section 1 04A and 104B, also 2 feet, has jets at an angle of 20 and a depth to accommodate 2 container diameters plus 3/4 inch. The conveyor 20A is shown as utilizing 10 jet angles and may be of any convenient length. The height in conveyor 1 OA will accommodate only one container diameter as described above.

It will also be appreciated that the air jet nozzles may be of variable angles as set forth in applicant's copending application such that different angular settings may be made as well as providing for selectively changing the angle of one or more jet nozzles during use as by means of microprocessor control and the like.

Claims (17)

1. An air conveyor system for the transfer of containers from one location to another while substantially avoiding contact therebetween which comprises an air conveyor having a pair of elongate side walls held in spaced relation to define a channel with the side walls being spaced apart a distance slightly greater than the height of the container, a top co-operating with the side walls to define an inverted U-shaped channel, a plenum adapted to be connected to a source of air under pressure attached to each side wall in coextensive relation thereto, a plurality of openings through the side walls communicating the plenums with the channel and positioned along a line substantially parallel to the lower extremity of the side walls, said openings comprising air jet nozzles angularly disposed to direct jets of air forwardly against the containers and at a point just above the axis of rotation of the containers at rest, and the lower extremity of the U-shaped channel being open with guide rails attached to either side wall and spaced from the top a distance slightly greater than the diameter of the container to be transferred.

2. The conveyor system of claim 1 wherein said air jet nozzles are angularly positioned at an angle of from between 5" to 50 from a line normal to the side wall in the direction of container travel.

3. The conveyor system of claim 2 wherein the angle of the air jet nozzle is in the range of from 8" to 11 from a line normal to the side wall in the direction of container travel.

4. The conveyor system of any preceding claim wherein said air jet nozzles are selectively positioned at different angles along the length of the conveyor.

5. The conveyor system of any preceding claim wherein, in use, the space between the containers and the top of the channel is not greater than about 1/4 inch.

6. A method of transporting a plurality of containers which comprises providing an inverted U-shaped channel having side walls and a top with cross sectional dimensions just slightly greater than the profile of the containers to provide a highly restricted air flow path between the containers and the sides and top of the channel, introducing containers into the channel while injecting air through longitudinally spaced jet openings in the side walls positioned at a downstream angle to impinge on the ends of the container and introducing air under pressure into the space between and above the containers while exhausting air from between and above the containers and from the channel through an open bottom at a rate to provide and maintain a positive pressure between and above the containers sufficient to maintain the containers separated one from another while being transported.

7. The method of claim 6 wherein the introduction of air between the containers is sufficient to provide a greater than ambient pressure therebetween.

8. The method of claim 6 or claim 7 wherein the air is introduced into the channel at an angle of from 5" to 50 with respect to a line normal to the side wall in the direction of container travel.

9. The method of claim 8 wherein the air jet angle is in the range of from 8'to 11 .

10. The method of any one of claims 6 to 9 wherein supplemental air is introduced into the space between the containers in addition to air supplied via the air jet nozzles.

11. The method of any one of claims 6 to 10 wherein the air jet nozzles are of a uniform size of from 7/32 to 11/32 inch in diameter.

12. The method of any one of claims 6 to 11 including the step of maintaining a spacing between the top of the channel and the container of not greater than about 1/4 inch.

13. The method of operating the conveyor system according to claim 1 wherein the air volume supplied to the inlet of the plenum in relation to the total cross sectional area of the air jet nozzles along with the static pressure to be maintained across the jet nozzles are selected to provide a substantially uniform static pressure in the channel throughout its length.

14. The conveyor system of any one of claims 1 to 5 wherein, for merging a plurality of streams of containers into a single feed line, a plurality of single filer means are provided each for receiving a plurality of containers in mass at its input and discharging the containers serially in a single file at its output, said air conveyor being adapted to receive the containers from one single filer and discharge the containers to the output of a second single filer at predetermined speed and spacing to accommodate the containers received from the second single filer and merge same with the output of the first single filer.

15. The method of merging containers from a plurality of sources which comprises feeding the containers into a plurality of single filer means each adapted to receive a plurality of containers in mass at the input and discharge the containers serially in a single file at its output, and feeding the output of each single filer means to merge with the output of the next serial single filer means, the containers being conveyed from the output of a single filer means to the next single filer means by the method according to any one of claims 6 to 13.

16. An air conveyor system substantially as herein described with reference to Figures 1 to 5 or Figures 1 to 7 of the accompanying drawings.

17. A method of conveying containers, the method being substantially as herein described.