A pneumatic conveying system and a method and use for collecting objects and transporting them to a collecting unit including cleaning means

Abstract

A pneumatic conveying system (1) and method for handling objects (2) and transporting them through convey lines to a collecting unit (3). It comprises at least one loading unit (4) adapted to receive said objects (2) and in gas / air flow connection to an inlet convey line (5) and an outlet convey line (6). The outlet convey line (6) is air / gas flow connected by conveying lines to a discharge convey line (7) from where the objects are led to the collecting unit (3). The system (1) comprises an air / gas pump (9) generating an air / gas flow through the inlet convey line (5) into the loading unit (4), a control system (10), pressure means for providing a negative air / gas pressure in the outlet convey line (6), a number of nozzles (30) placed in the wall of the conveying lines between the loading unit (4) and an outlet (14). The nozzles (30) are connected to a liquid / water source (31) and allows communication between the inner of the lines and the liquid / water source (31) whereby liquid / water droplets / spray are entering the inner of the conveying system (1).

Description

[0001] A pneumatic conveying system and a method and use for collecting objects and transporting them to a collecting unit including cleaning means

[0002] The present invention relates to a pneumatic conveying system for handling objects and transporting the objects through convey lines to a collecting unit, the system comprises

[0003] - at least one loading unit adapted to receive said objects through a receiving opening and in gas / air flow connection to an inlet convey line and an outlet convey line, air / gas flow allowed to pass through the inlet convey line, the loading unit(s) and the outlet convey line,

[0004] - said outlet convey line air / gas flow connected by conveying lines to a discharge convey line from where the objects are led to the collecting unit through an outlet of the discharge convey line,

[0005] - said system comprising an air / gas pump adapted to generate an air / gas flow through the inlet convey line into the loading unit,

[0006] - and that the system further comprises a control system.

[0007] The invention also relates to a method for collecting and transporting objects through a pneumatic conveying system from at least one loading unit through convey lines leaving the convey lines through an outlet of a discharge convey line and to a collecting unit where the objects are collected, an air / gas flow is flowing from an inlet convey line into the loading unit(s) and further to an outlet convey line and an air / gas pump is pumping air / gas through the inlet convey line, and a control system is controlling the pressure in the pneumatic conveying system.

[0008] Further the invention relates to the use of the pneumatic conveying system for performing the method.

[0009] The objects may be items such as empty beverage bottles and cans of any size and material such as plastic, steel, aluminum, glass, plastic said objects often recycling waste material. The objects may also be disposable packaging.

[0010] Pneumatic conveying systems are used for transporting different kinds of material such as food, corn and granulates. Generally, air is blown through pipes via a pressure blower or similar in order to move the material through the pipe. In this way the material in question can be moved from one point to another.

[0011] US 6164491 B discloses a pneumatic product vending and delivery system. The system transports products such as bottles from a remote storage location to a vending terminal where a costumer may select a specific bottle through a control panel. A blower assists in transporting the bottles through the tube. The system is not adapted for transporting empty packaging such as bottles and cans from a delivery station to a container.

[0012] US 4180354 A discloses a pneumatic tube transmission system for transmitting a carrier in which an object is placed from one terminal to a remote terminal to allow delivery of the carrier into an open remote terminal. When the carrier is being transferred from the first terminal to the remote terminal, the carrier is positioned in the first terminal and the blower is activated to de liver positive pressure air through the first airline. A second airline draws a partial vacuum on the second end of the transmission line at the remote terminal. This forces the carrier to move through the line to the remote terminal where the object is removed from the carrier. The system is not suitable for transporting objects continuously.

[0013] BE 710678 A discloses a pneumatic tube system where a suction in the tube sees to that objects such as bottles are transported through the tube. The system requires that each object is placed in the tube one by one.

[0014] A container return system is generally arranged to collect waste containers for recycling. This may include used emptied beverage bottles and cans, or other waste material.

[0015] The container return system must collect large numbers of waste material for recycling in a short period of time. In many installations, the container return system delivers the received objects to a backroom receiving facility and the required space here can be considerable. Further it can also require means for sorting and storing the received objects. The space requirement and the complexity cause cost to the system.

[0016] In a typical installation, the crushed or compressed objects are transferred to a box and stored in plastic bags. The plastic bag is replaced when full. This also requires available space to store the full plastic bag and is time consuming. Further the container return system is often stopped when the box is full and needs to be replaced by an empty one.

[0017] In order to handle recycling packages such as bottles and cans it is common to transport the objects on a transport band. This transport band runs from a delivery station where the customer enters the bottle / can and to a box where the bottles / cans are selected. Such system is known from EP 0612046 A.

[0018] It comprises a front panel comprising a receiving opening for the bottles / cans and a transfer conveyer to transport the bottles / cans to a collecting box.

[0019] These systems are quite time consuming for the customer as the system is fed one by one, that is the customer must wait for one bottle / can to disappear before a new one is fed to the system. Further the collecting boxes are filled in short time and must be replaced by a new one. This is also timerequiring and requires staff just for emptying the boxes. Further, rest liquid and rest food from the waste material make the inside of the system dirty so it is necessary to stop the system and to clean it now and then.

[0020] With other words it is desirable to develop an improved convey system for collecting and transporting waste material in such a way that the waste material can be handled without any delay and the system is self-cleaning, whereby no further interruption of the system takes place. The waste material is transported away from the delivery station so fast that the user just can empty large portions of the waste material into the delivery station without any risk for overloading the system.

[0021] The present invention seeks generally to improve pneumatic conveying systems for collecting and transporting objects such that the abovementioned insufficiencies and drawbacks of today's conveying systems are overcome or at least it provides a useful alternative.

[0022] Up to this day, prior art has failed to teach a simple and yet reliable and inexpensive conveying system which in a safe and reliable manner, without substantially increasing the cost of the system, is able to satisfy the abovementioned much desired characteristics of the mentioned conveying system. According to the invention, a pneumatic conveying system is provided, as per the introductory part of this specification, and which system further comprises pressure means for providing a negative air / gas pressure in the outlet convey line, and a number of nozzles placed in the wall of the conveying lines and / or the loading unit in a region from the loading unit and to the outlet, which nozzles are adapted to be connected to a liquid media source placed outside the convey lines, the nozzles allowing communication between the inner of the lines and the liquid media source whereby liquid droplets / spray are entering the inner of the conveying system.

[0023] In general, the liquid media source comprises a liquid media having cleaning or disinfecting or odor removing or otherwise benefactory abilities. The liquid media may be a cleaning media such as water or an aqueous or organic solution comprising cleaning, disinfecting, or odor removing components.

[0024] The pressure devices may comprise any type of air-source such as a blower, air pump, fan, or other device capable of creating a pressure differential and for forcing air or other gas, under pressure, through the convey line. As such, the pressure devices are configured to generate a positive air- pressure for purposes of introducing air into the first convey line and an air flow with a certain laminar flow velocity in the loading unit and for causing an under-pressure in the outlet convey line. This causes the objects introduced into the convey lines to travel through the convey lines. The means for providing a negative pressure generate a negative air pressure within the outlet convey line below an ambient atmospheric pressure. The air / gas pump is required to generate a pressure above ambient pressure inside the inlet convey line.

[0025] As the waste material - such as empty plastic bottles or cans - drop down in the loading unit and reaches the bottom part of this, the laminar flow in the loading unit caused by the pressure difference between the inlet convey line and the outlet convey line is sucked into the outlet convey line and passes through the injector and further to the discharge convey line. From here it is dropped down into the collecting unit which is typically a big container placed outside the building where the system is placed.

[0026] In this way the convey system can operate through the whole day without any interruptions, as such a container can hold more than 150 times what a bag used in the known systems is capable of. Further, the system does not require staff inside the building to be responsible for watching the system being full and stopping it each time a box / bag is full. The full container - placed outside the building where the system is placed - is driven directly away without bothering any inside-staff. An additional benefit is that the plastic bags used in the existing systems are not necessary.

[0027] The system combines pneumatic vacuum transport and pneumatic overpressure transport, and the control system controls the two pressures in such a way that we have nearly even pressure (0,9-1 bar) in the loading unit, and a laminar flow through the loading unit of around 10-40 m / second. The waste material is in this way pushed into the inlet convey line, where the under-pressure sucks the material to the discharge convey line from where it is dropped down into the container. An injector let the material pass through, while the injector also causes an under-pressure in the outlet convey line, as the pressurized air from the pressure blower passes through the injector.

[0028] There may be more than one loading unit. If two loading units are used, they are connected to each other by a pipe / tube and the inlet convey line is connected to the first loading unit while the outlet convey line is connected to the second loading unit. As the objects are dropped down into the loading unit, they often leek liquid or food rest which is quite sticky. For that reason, there is a need for cleaning the system inside. Further, the objects are often compressed / crushed / punctured before they are led into the tubes of the conveying system, which increases the need for cleaning the tubes inside as the crushed objects will leek food-rest or liquid in larger amounts. These residues are sugary, sticky and greasy and will adhere to the inside of the tubes. So, after a while typically every second hour a day the system must be stopped in order to clean the inside and there are such needs for stopping the pneumatic transport system if it is not cleaned. This problem overcomes the invention by having nozzles placed in the wall of the tubes and or the loading unit allowing liquid media to enter the inside of the system.

[0029] The nozzles are placed in the wall of the pneumatic tubes and the loading unit and advantageously quite near or in the wall of the outlet convey line. Several nozzles are placed with a certain distance between each other in order to work over a larger area. The nozzles are connected to a liquid media source, typically a water source. The liquid media leaves the liquid media source under pressure, when the liquid media source is opened. The liquid media is then spraying through the nozzles into the inner of the tubes / convey lines / loading unit and the droplets / liquid dust is carried along by the gas flowing through the convey system. The droplets / dust are in this way cleaning the inside of the convey system and the need to stop the system for cleaning it is hereby reduced or quite unnecessary. The number of nozzles is typically between 2-10. The liquid media source may comprise water from the publicly accessible water system, or it may comprise water from a specific water reservoir where means for providing pressurized water is established. The nozzles and pressure cause the water to atomize and is sucked further into the system cleaning it and traveling through it by the laminar airflow inside the system.

[0030] The liquid media is typically supplied from the liquid media system through a valve such as a solenoid valve which is controlled by the control system. When the valve is opened the liquid passes through the tubes connected to the nozzles and further through some or all the nozzles. In this way all the nozzles are spraying liquid into the system.

[0031] According to one embodiment several nozzles are at least placed in a second convey line - which is air / gas flow connected to the discharge convey line and directly connected to the outlet convey line - said nozzles are placed with a distance between each other in a longitudinal direction of the second convey line. By "directly" is to understand that there is a physical connection between the outlet convey line and the second convey line.

[0032] The nozzles are advantageously placed in the very beginning of the transport of the objects but may also be placed near the outlet of the system and there between.

[0033] When the nozzles are opened, and water from the water source is under a certain pressure in order to enter the nozzles, droplets and spray are made and will travel through the inner of the lines due to the gas flow. Since they are placed at the start of the system a cleaning of the entire system will take place. The sticky substances from the objects such as rest of beer and soda will be washed away.

[0034] According to one embodiment, at least one nozzle is placed in the outlet convey line and or the loading unit.

[0035] According to one embodiment, the liquid media source is a pressurized liquid media source. According to one embodiment, the nozzles are all connected to a valve having an open position and a closed position said open position allowing liquid to flow through all or some of the nozzles. In the closed position of the valve, no liquid enters the nozzles and therefore not the system. The valve is connected to the nozzles by tubes. The valve is typically a solenoid valve.

[0036] According to one embodiment, the open or closed position of the valve is controlled by the control system.

[0037] The control system may control many parameters of the system. Not only the gas / air pressure of the inside of the conveying system but also the pressure of the water and the opening and closing of the valve.

[0038] According to one embodiment, the pressure means comprise a pressure blower for providing pressurized gas / air, said pressure blower air / gas flow connecting with the discharge convey line, the pressure blower is by a first convey line air / gas flow connected to an injector and arranged to form a negative air / gas pressure in the outlet convey line.

[0039] According to one embodiment, the control system is configured to control the air / gas pressure from the pressure means, and the pressure from the air pump, by said pressure the objects pass from a bottom part of the loading unit(s) through the outlet convey line and further through the injector and the discharge convey line into the collecting unit.

[0040] According to one embodiment, the injector gas / air flow is connected by the second convey line to the outlet convey line, the injector is further gas / air flow connected to the discharge line, said injector allowing the objects to pass through the injector and leave the injector through the discharge convey line.

[0041] The pressurized air passes through the injector and to the discharge convey line, to which it is directly connected. As the injector also has a connection to the outlet convey line of the collecting unit through the second convey line, the flow from the blower through the injector makes an underpressure or a negative pressure in the second convey line and thereby in the outlet convey line of the loading unit. The objects are also passing through the injector.

[0042] According to one embodiment, the control system is adapted to control the pressure in the system in such a way, that a laminar airflow in the loading unit is around 10-40 m / s preferably 20-30 m / s.

[0043] According to one embodiment, the pressure in the outlet convey line is below ambient atmospheric pressure, and the pressure in the inlet convey line is essentially above ambient atmospheric pressure.

[0044] The control system may ensure that the air flow velocity in the loading unit is suitable, that is around 10-40 m / s, preferably 20-30 m / s and more preferably 25-30 m / s. This is done by regulating the pressure in the inlet convey line and the outlet convey line. When the waste material leaves the loading unit the under-pressure or negative pressure in the outlet convey line ensures that the waste material is sucked up to the injector and from the injector is pushed out caused by the airflow from the pressure blower passing through the injector.

[0045] The flow is approximately laminar, which ensures that the objects do not stop the system but pass through it without getting tangled together. According to one embodiment, the pneumatic conveying system may comprise a compactor adapted to compress and / or puncture the objects before the objects reach the loading unit.

[0046] Before the objects are dropped into the loading unit, they may be advantageous to compress the objects, depending on which objects are transported in the system. Further, sometimes it is advantageous to puncture the objects, which also can be done in a compactor before dropping them into the loading unit. When applying a compactor, the objects may leak more liquid / food rests making it even more important that the system has self-cleaning devices incorporated.

[0047] According to one embodiment, the objects are deposit objects such as bottles and cans in can bottle and can deposit recycling systems and / or disposable packaging.

[0048] "Deposit recycling" means recycling of materials where consumers pay a deposit.

[0049] The invention also concerns a method for collecting and transporting objects through a pneumatic conveying system as described in the introductory part of the description, where a suction is provided in the outlet convey line connected to the loading unit, which suction is provided by pressure means, and nozzles connected to a liquid media source - and placed in the wall of the convey lines and / or the loading unit in a region from the loading unit and to the outlet - are spraying droplets or liquid dust into the inner side of the convey system when liquid media is flowing to the nozzles and the droplets / spray / liquid dust are transported through the convey system by the air / gas flow towards the collecting unit and during their travel cleaning the inside of the convey system.

[0050] According to one embodiment, a plurality of nozzles are placed in a second convey line and / or a wall of the loading unit - which is air / gas flow connected to the discharge convey line - and directly connected to the outlet convey line the nozzles spraying droplets / liquid dust into the inner of the lines, when liquid is flowing into the nozzles, and the nozzles are placed with a distance between each other in a longitudinal direction of the lines distributing the liquid over a certain area.

[0051] By having the nozzles placed in the wall of the loading unit and / or just after the outlet convey line the washing process of the convey system takes place immediately. If the nozzles are placed in a distance from the outlet convey line, there would be an area where no cleaning process took place.

[0052] According to one embodiment, at least one nozzle is placed in the wall of the outlet convey line and / or the loading unit and cleaning the inside of the outlet convey line and the convey lines with pressurized droplets / spray / liquid dust when the liquid is flowing into the nozzle(s).

[0053] According to one embodiment, the pressure means comprise a pressure blower to which the outlet convey line is air / gas flow connected and the pressure blower blows air / gas through a first convey line, through an injector causing the suction in the outlet convey line, the control system is controlling the pressure inside the conveying lines so the pressure inside the inlet convey system is above an ambient atmospheric pressure, and the pressure inside the outlet convey line is below an ambient atmospheric pressure providing an air / gas flow velocity in the loading unit, whereby the objects are moved through the conveying lines into the collecting unit and liquid droplets / spray are traveling through the system when the nozzles are in open position.

[0054] According to one embodiment, a second convey line is provided between the injector and the outlet convey line a suction in the outlet convey line as the pressurized air from the pressure blower flows through the injector. According to one embodiment, the control system is controlling the opening or closing of a regulator such as a valve, said valve connected to the nozzles, and when the valve is opened by the control system it allows liquid to pass into some or all the nozzles and from here into the system as droplets / liquid dust and the airflow transport the droplets / liquid dust through the system to the outlet thereby cleaning the inside of the system.

[0055] According to one embodiment, a laminar airflow is obtained around 10-40 m / s preferably 20-30 m / s, and the pressure inside the outlet convey line is below ambient atmospheric pressure, and the pressure inside the inlet convey line is essentially above of an ambient atmospheric pressure.

[0056] According to one embodiment, objects may be fed into the loading unit in a continuous stream i.e. without the flow of objects being constituted of separate items.

[0057] According to one embodiment, the discharge line comprises at least one first portion with a diameter dl placed directly in connecting with the injector, and a second portion with a diameter d2 placed in a distance to the injector said d2>dl. By changing the diameter of the discharge line bigger, the pressure inside the line / tube is reduced. The laminar velocity is around 10-15 m / sec in the region with the diameter d2. Hereby the material falls down into containers in a regulated manner, and without it being pushed out of the system with too much force. It falls quite easily into the container.

[0058] The two regions respectively with diameter dl and d2, are connected by a tube connecting piece e.g. a conic transition tube.

[0059] According to one embodiment, the loading unit comprises a horizontal tube comprising the bottom part of the loading unit connecting the pneumatic inlet and outlet convey lines directly with each other, and the loading unit further comprises a hopper placed above the tube and connected to the tube and with an opening in the bottom allowing the objects to drop down into the tube through an opening in said tube.

[0060] The tube is typically an integrated part (made in one) of the inlet and outlet conveying lines with an opening in the top for receiving the objects to the bottom part. The loading unit comprises a hopper comprising an opening in the bottom matching the opening of the tube. The hopper is typically connected to the tube by welding the lower edge of the hopper to the outside wall of the tube.

[0061] According to one embodiment, the receiving-opening of the loading unit points in the opposite direction of gravity.

[0062] According to one embodiment, the collecting unit is a container with a space-volume of at least 2 m3, preferably more than 2 m3, more preferably more than 10 m3placed at an outlet of the discharge line for catching the objects falling down in said container.

[0063] Using big containers - normally placed outside the building where the system is placed - removes the need to collect the material in bags. The material simply drops down into the big container as it is, that is compressed or not compressed. The need to stack bags with the material for recycling is hereby removed.

[0064] The big containers can be as large as 6, 5*2, 5*3 m3that is 48,75 m3. The big container may alternatively be a big plastic bag attached to the outlet.

[0065] According to one embodiment, all the convey lines including the inlet convey line, the outlet convey line and discharge convey line are pneumatic transfer tubes. By "pneumatic transfer tubes" is to understand, that the tubes are transporting under-pressure or over-pressure gas / air and are able to withstand the different pressures.

[0066] According to one embodiment, a negative pressure or equal pressure is provided in the upper part of the loading unit.

[0067] By having a slight negative pressure in the upper part of the loading unit odor will be sucked out with the material flow.

[0068] Brief description of the drawings

[0069] FIG. 1 is a perspective view of a pneumatic conveying system according to the invention.

[0070] FIG. 2 is a perspective view of a loading unit of the pneumatic conveying system shown in fig 1.

[0071] FIG. 3 is a sectional view through an injector of the pneumatic conveying system shown in fig 1.

[0072] Fig. 1 shows a pneumatic conveying system 1 according to the invention, where an object 2 such as a plastic bottle is thrown down into a loading unit 4 to be transported through the conveying lines of the system. The object 2 is typically delivered from a delivery station placed in a store, where the customer delivers bottles / cans back to the store in order to have the waste objects 2 recycled. An object 2 is also seen in fig. 1 leaving the system through an outlet 14 of a discharge convey line 7. The objects 2 - delivered to the system 1- may be delivered in a continuous flow. The customer may simply empty a whole sack of objects 2 into the loading unit 4 at the delivery station as the system 1 is able to receive and handle the objects 2 without any delay as the objects 2 is automatically removed from lower part of the loading unit 4 one by one.

[0073] The pneumatic conveying system 1 comprises the loading unit 4 that receives the objects 2. The loading unit 4 is explained in detail with reference to fig 2. The loading unit 4 is physically connected to an inlet convey line 5 - a tube - and an outlet convey line / tube 6. A flow of air or gas passes through the inlet convey line 5, the loading unit 4 and the outlet convey line 6. The outlet convey line 6 is flow connected with an injector 11 through a second convey line 12, which is also air / gas flow connected to the discharge convey line 7. A pressure blower 8 provides pressurized gas / air and is through a first convey line 18 air gas connected with the injector 11 and thereby the discharge convey line 7.

[0074] The pressure blower 8 forms a negative pressure inside the outlet convey line 6 and the second convey line 12 which is fluidly connected to an inlet of the injector 11, due to that the air blower 8 establishes a gas / air flow from a side opening or a radial opening to the outlet of the injector 11.

[0075] An air / gas pump 9 generates an air / gas flow through the inlet convey line 5 into the loading unit 4. A strong airflow is then obtained at the bottom part of the loading unit 4, normally around 10-40 m / s, due to the pressure in the outlet convey line 6 is below ambient atmospheric pressure (suction), and the pressure in the inlet convey line 5 is above ambient atmospheric pressure. Thereby the objects 2 pass from a bottom part of the loading unit 4 through the outlet convey line 6 and further through the injector 11 and the discharge convey line 7, through the outlet 14 of the discharge convey line 7 into the collecting unit 3. Normally, the pressure inside the convey lines is controlled by a control system 10 e.g. by controlling the effect of pressure blower 8 and to air pump 9.

[0076] The discharge convey line 7 of the embodiment comprises a first portion 15 with a diameter dl of the tube of around 200 mm placed directly in connecting with the injector 11. A second portion 16 with a diameter d2 of the tube of around 400 mm is placed in a distance to the injector 11. The two pieces are connected to each other with tube connection piece which in the shown embodiment is a conic transition-tube. By increasing the diameter of the tube close to the outlet 14 of the discharge convey line 7 , the flow velocity of the air / gas is reduced at the outlet 14, and the objects 2 simply falls down into the container placed under the outlet 14 instead of being blown out of the outlet 14.

[0077] The cleaning system for cleaning the inside of the conveying system 1 comprises nozzles 30 connected to a source 31 of liquid media via tubes 32. The liquid media may be water such as tap water or demineralized water, or the liquid media may be an aqueous solution comprising a cleaning component such as soap, or an odor removing component, or the liquid media may be an organic liquid for removing organic-soluble components from the inside of the covey lines. Also, there system may comprise more than one source of liquid media and the liquid media supplied to the system may change between two or more sources during one cleaning operation.

[0078] The nozzles 30 are in the shown embodiment placed in the wall of the second convey line 12 where one nozzle 30 is placed just after the outlet convey line 6. The other nozzles 30 are placed with a distance between them in the longitudinal direction of the line. Other nozzles 30 are placed closer to the outlet 14. The nozzles could also be placed in the wall of the loading unit 4 and the outlet convey line 6.

[0079] The nozzles 30 may be connected to a valve 33 having an open position and a closed position, where the open position allows liquid cleaning media to flow from the liquid cleaning media reservoir 31 to flow to all some or to all the nozzles 30 and through them. The open or closed position of the valve 33 may be controlled by the control system 10.

[0080] The nozzles 30 allow - when controlled by the valve 33 and the valve 33 is opened - that water- droplets / dust / spray to enter into the inside of the pneumatic conveying system 1 and are carried by the air flow through the system 1 and clean the inside of the system from residuals that the objects 2 have introduced into it. These residues being sugary, sticky and greasy and adhering to the inside of the tubes and devices and now removed by the flow of the liquid media dust / droplets.

[0081] The nozzles 30 may alternatively or also be placed in other areas such as in the wall of the outlet convey line 6 and in the wall of the loading unit 4.

[0082] One or several nozzles 30 may also be placed in the wall of the discharge line 7 depending on how greased the system 1 becomes, which in turn depends on the contents of the objects 2.

[0083] Fig. 2 illustrates an embodiment of a loading unit 4. This embodiment of the loading unit 4 comprises a hopper 20 configured to receive objects 2 which hopper 20 is physically connected to an approximately horizontal tube 19 constituting a bottom part of the loading unit 4, the objects 2 are guided into the horizontal tube 19 by the hopper and driven there by gravity. The tube 19 is fluidly connected to the two convey lines 5,6 creating a connection between them. The hopper 20 is placed above the tube 19 and is connected directly to the tube 19, the hopper 20 comprises an opening at the bottom allowing objects 2 to enter from the hopper 20 into the tube 19 through which comprises a corresponding opening. The whole construction may be supported by a frame 21. The tube 19 provides a the bottom of the loading unit / hopper 4,20.

[0084] Fig 3 shows a sectional view through the injector 11. The arrows show the airflow through the injector 11, fig. 3 also illustrates how an object 2 passes into the injector 11 as a result of the suction provided by the airflow - from the pressure blower 8 - through the injector 11. When an object 2 has passed through the injector 11, the object 2 is carried out of the conveying line due to the pressurized air / gas from the pressure blower 8.

[0085] The objects 2 may be compressed or punctured by a device such as a compactor / dual roller before they are dropped down in the loading unit 4. This device is not shown in the figures.

Claims

Claims1. A pneumatic conveying system (1) for handling objects (2) and transporting them through convey lines to a collecting unit (3), the system (1) comprising- at least one loading unit (4) adapted to receive said objects (2) through a receiving opening and in gas / air flow connection to an inlet convey line (5) and an outlet convey line (6), air / gas flow allowed to pass through the inlet convey line (5), the loading unit(s) (4) and the outlet convey line (6),- said outlet convey line (6) air / gas flow connected by conveying lines to a discharge convey line (7) from where the objects are led to the collecting unit (3) through an outlet (14) of the discharge convey line (7),- said system (1) comprising an air / gas pump (9) adapted to generate an air / gas flow through the inlet convey line (5) into the loading unit (4),- and that the system (1) further comprises a control system (10) characterized in that it further comprises- pressure means for providing a negative air / gas pressure in the outlet convey line (6), -and a number of nozzles (30) placed in the wall of the conveying lines and / or the loading unit (4) in a region from the loading unit (4) and to the outlet (14),- said nozzles (30) are adapted to be connected to a liquid media source (31) placed outside the convey lines, the nozzles (30) allowing communication between the inner of the lines and the liquid media source (31), whereby liquid media droplets / spray are entering the inner of the conveying system (1).

2. A pneumatic conveying system (1) according to claim 1 characterized in that several nozzles (30) are placed at least in a second convey line (12) - which is air / gas flow connected to the discharge convey line (7) and directly connected to the outlet convey line (6) - said nozzles (30) are placed with a distance between each other in a longitudinal direction of the second convey line (12).

3. A pneumatic conveying system (1) according to claim 1 or 2 characterized in that at least one nozzle (30) is placed in the outlet convey line (6) and / or the loading unit (4).

4. A pneumatic conveying system (1) according to any of the previous claims characterized in that the liquid media source (31) is a pressurized liquid media source.

5. A pneumatic conveying system (1) according to any of the previous claims characterized in that the nozzles (30) are connected to a valve (33) having an open position and a closed position, said open position allowing liquid media to flow through all or some of the nozzles (30).

6. A pneumatic conveying system (1) according to claim 5 characterized in that the open or closed position of the valve (33) is controlled by the control system (10).

7. A pneumatic conveying system (1) according to any of the previous claims characterized in that the pressure means comprise a pressure blower (8) for providing pressurized gas / air, said pressure blower (8) air / gas flow connecting with the discharge convey line (7), the pressure blower (8) is by a first convey line (18) air / gas flow connected to an injector (11) and arranged to form a negative air / gas pressure in the outlet convey line (6).

8. A pneumatic conveying system (1) according to according to any of the previous claims characterized in that the control system (10) is configured to control the air / gas pressure from the pressure means, and the pressure from the air pump (9), by said pressure the objects pass from a bottom part of the loading unit(s) (4) through the outlet convey line (6) and further through the injector (11) and the discharge convey line (7) into the collecting unit (3).

9. A pneumatic conveying system (1) according to claim 7,8 characterized in that the injector (11) is gas / air flow connected by the second convey line (12) to the outlet convey line (6), the injector (11) is further gas / air flow connected to the discharge line (7), said injector (11) allowing the objects (2) to pass through the injector (11) and leave the injector (11) through the discharge convey line (7).

10. A pneumatic conveying system (1) according to any of the previous claims characterized in the control system (10) is adapted to control the pressure in the system (1) in such a way, that a airflow in the loading unit (4) is around 10-40 m / s preferably 20-30 m / s.

11. A pneumatic conveying system (1) according to any of the previous claims characterized in the pressure in the outlet convey line (6) is below ambient atmospheric pressure, and the pressure in the inlet convey line (5) is essentially above ambient atmospheric pressure.

12. A pneumatic conveying system (1) according to any of the previous claims characterized in that the pneumatic conveying system (1) further comprises a compactor such as a dual roller adapted to compress and / or puncture and / or crush the objects (2) before the objects (2) reach the loading unit (4).

13. A pneumatic conveying system according to any of the previous claims characterized in that the objects (2) are deposit objects such as bottles and cans in can bottle and can deposit recycling systems and / or disposable packaging.

14. Method for collecting and transporting objects (2) through a pneumatic conveying system (1) from at least one loading unit (4) through convey lines leaving the convey lines through an outlet (14) of a discharge convey line (7) and to a collecting unit (3) where the objects are collected, an air / gas flow is flowing from an inlet convey line (5) into the loading unit(s) (4) and further to an outlet convey line (6) and an air / gas pump (9) is pumping air / gas through the inlet convey line (5), and a control system (10) is controlling the pressure in the pneumatic conveying system (1) characterized in a suction is provided in the outlet convey line (6) connected to the loading unit (4), said suction is provided by pressure means, and nozzles (30) connected to a liquid media source (31) - and placed in the wall of the convey lines and / the loading unit (4) placed in a region from the loading unit (4) and to the outlet (14) - are spraying droplets and / or liquid dust into the inner side of the convey system (1) when liquid media is flowing to the nozzles (30), and the droplets / spray / liquid dust are transported through the convey system (1) by the air / gas flow towards the collecting unit (3) and during their travel cleaning the inside of the convey system (1).

15. Method according to claim 14 characterized in that at least several nozzles (30) placed in a second convey line (12) and / or a wall of the loading unit (4) - which is air / gas flow connected to the discharge convey line (7) and directly connected to the outlet convey line (6) - are spraying droplets / liquid dust into the inner of the lines when liquid media is flowing into the nozzles, and the nozzles (30) are placed with a distance between each other in a longitudinal direction of the lines distributing the liquid media over a certain area.

16. Method according to claim 14 or 15 characterized in that at least one nozzle (30) is placed in the wall of the outlet convey line (6) and / or the loading unit (4) and cleaning the inside of the outlet convey line (6) and the convey lines with pressurized droplets / spray / liquid dust when liquid media is flowing into the nozzle(s).

17. Method according to claim 14, 15 or 16 characterized in the pressure means comprise a pressure blower (8) to which the outlet convey line (6) is air / gas flow connected, and the pressure blower (8) blows air / gas through a first convey line (18), through an injector (11) causing the suction in the outlet convey line (6), the control system (10) is controlling the pressure in the conveying lines so the pressure in the inlet convey system (5) is above an ambient atmospheric pressure, and the pressure in the outlet convey line (6) is below an ambient atmospheric pressure providing an air / gas flow velocity in the loading unit (4), whereby the objects (2) are moved through the conveying lines into the collecting unit (3) and liquid droplets / spray are traveling through the system (1) when the nozzles (30) are in open position.

18. Method according to claim 17 characterized in that a second convey line (12) between the injector (11) and the outlet convey line (6) provides a suction in the outlet convey line (6) as the pressurized air from the pressure blower (8) flows through the injector (11).

19. Method according to claim 14, 15, 16 or 17 characterized in that the control system (10) is controlling the opening or closing of a regulator such as a valve said valve (33) connected to the nozzles (30), and when the valve (33) is opened by the control system (10) it allows liquid media to pass into some or all the nozzles, and from here into the system (1) as droplets / liquid dust where the airflow transport the droplets / liquid dust through the system to the outlet thereby cleaning the inside of the system (1).

20. Method according to claim 14,15,16,17,18 or 19 characterized in that a laminar airflow is obtained around 10-40 m / s preferably 20-30 m / s, and the pressure in the outlet convey line (6) is below ambient atmospheric pressure, and the pressure in the inlet convey line (5) is essentially above of an ambient atmospheric pressure.

21. Use of the pneumatic conveying system (1) according to claims 1-13 for performing the method according to claims 14-20.

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