EP2814739A1

EP2814739A1 - System and method for dispensing particulate material

Info

Publication number: EP2814739A1
Application number: EP12707138.9A
Authority: EP
Inventors: Carlo LOTTI; Mario Besana; Vittorio VERONELLI
Original assignee: CBC (Europe) Srl
Current assignee: CBC (Europe) Srl
Priority date: 2012-02-15
Filing date: 2012-02-15
Publication date: 2014-12-24
Also published as: WO2013121247A1

Abstract

The present invention relates to a system and a method for filling particulate material from a source container into a destination container, wherein said material is in the form of a fine particulate powder. The system comprises an air mixer funnel which allows the quick connection to an outlet opening of a particulate source container and can dispense the particulate material by creating a uniform flow that guarantees the particulate powder flowing without stacking.

Description

System and method for dispensing particulate material

Field of the invention

The present invention relates to a system and a method for dispensing particulate material from a source container into one or more destination containers, wherein said material is in the form of a fine particulate powder.

State of the art

Different methods are known in the art which make use of dispensing devices for filling containers of particulate material from a source container. This operation is mostly correlated with the need of conveying the particulate stored in the source container into smaller receptacles intended for a more practical handling.

Known methods of dispensing materials in powdered form incorporate funnel- shaped devices, wide at their inlet and narrow at their outlet, and generally utilize gravity for dispensing said material. Other solutions comprise the use of screw conveyors which guide the powder to the exit of the filling funnel, while in some other applications compressed air is filled inside the dispenser device for fluidizing the material and enhancing its flowing properties. Agitating or vibrating means are also used to unblock the funnels to prevent blockages, but they result inevitably in a very complex system requiring particular maintenance and involving high costs.

Examples of such systems and of their analogous embodiments are described e.g. in the publications indicated below. U.S. Pat. No. 5,337,794 describes a powder filling apparatus and a method for filling a container with powder. The toner container is filled by conveying toner from a supply hopper through a nozzle with a valve on the end. The valve is disposed at the bottom opening of the nozzle to release and close the opening of the nozzle by the vertical movement of the valve element.

U.S. Pat. Appl. 2004/011425 discloses a method and an apparatus for directing toner from a hopper containing a supply of toner. The apparatus includes a conduit member connected to the hopper and having a discharging end for permitting a toner to be moved there through, a conveyor device located at least partially within the conduit member for moving the toner from the hopper in a toner moving direction towards the container and a nozzle device including a nozzle member for directing the toner from the conveyor to cleanly fill the container. A miniature vibrator assists in providing the flow of particulate material from the hopper to the container.

U.S. Pat. No. 5,095,338 teaches a developer which discharges used carrier particles using a magnetic valve. Discharge of developer material from the developer housing is controlled by a permanent magnet and an electromagnet positioned adjacent an exit port in the developer housing. The permanent magnet generates a magnetic flux field in the region of the exit port to form a developer material curtain which prevents the passage of developer material from the exit port. When the electromagnet is energized, it generates a magnetic flux field which attracts developer material from the developer material curtain. Upon de-energization of the electromagnet, the developer material attracted to it is discharged.

U.S. Pat. No. 4,561 ,759 discloses a device for filling and filtering toner from a supply container. A filter basket is disposed in the region of the filling opening which is closed from the feed container by a filter mesh and an electric vibrator connected thereto by a linkage which can be automatically triggered at the beginning of a filling operation. U.S. Pat. No. 4,976,296 teaches a filling machine for filling containers with particulate material using a nozzle having an outlet end for delivery of particulate material to a container. The nozzle is encircled by a downwardly facing seal to engage the upper open end of the container. The nozzle has an outer annular cavity terminating in an annular port around the open end of the nozzle in which a relatively high vacuum is drawn to evacuate the container and draw material through the passageway into the container. The nozzle has an inner annular cavity terminating in a porous wall encircling the discharge end of the nozzle in which a relatively low vacuum is drawn to adhere material in the nozzle to the wall to terminate flow through the nozzle.

EP 11 15036 describes a powder discharging device for discharging coloring powder from a powder container via an outlet formed in the container, the powder container including a deformable bag storing the colouring powder, a position maintaining device configured to maintain the position of the bag, and a mounting portion configured to removably mount the bag. A gas is fed into the bag in order to fluidize the coloring powder and cooperates with the position maintaining device to maintain the position of the bag.

In all the above cases the main issue which affects the effective filling operations of the particulate material is the unavoidable clogging of the powder at the discharge opening of the dispensing units, with particular reference to funnels, with consequent blocking of the material flow. This is mainly due to the fact that even in the fluidized form, i.e. even with the application of pressurized air, the streams of material formed inside the dispensing units are made of randomly oriented fluxes which generate particle collisions responsible of non-uniform discharge of material and consequent formation of deposit rests. Object of the invention

The present invention seeks therefore to avoid the mentioned disadvantages and has the primary object of providing a system and a method for dispensing particulate material into a destination container, allowing a controllable, uniform flow of material without the risk of blockages and clogging which may interrupt its discharge.

A further object of the invention is to provide a particulate material filling device which can be easily coupled and adapted to the particulate containers - the one to be emptied and to the one to be filled - in an easy and quick way, thus limiting the operation time and costs and contemporarily avoiding any leakage of material.

It is still a further object of the invention to provide a method which reflects the above needs.

Disclosure of the invention

The above-cited objects are solved by means of a system for filling particulate material from a source container into a destination container, according to the subject-matter of claim 1. Additional advantages are defined in the dependent claims. The present application discloses also a method which makes use of the described system, as defined in claim 13.

The system and the method according to the present invention will be now explained in details with particular reference to the attached figures. The system according to the present invention includes an air mixer funnel 1 which comprises an air inlet nozzle A extending from the inside of a main body B of the funnel 1 into the source container 8, wherein said nozzle A is provided with perforations a^ to a_n with n integer >1 , through which air flows inside the main body B and/or the source container 8.

The system may further comprise

• an adapter 6 coupled with the main body B and

• a ring 7, engaging the adapter 6 or the main body B for connecting the air mixer funnel 1 with an outlet opening 9 of a particulate source container 8.

For a better understanding of the relative positions and orientations of the cited components, reference is made to the attached figures.

As it can be seen from Fig.1 , the main body B of the air mixer funnel 1 has an upper part b1 with cylindrical cross-section and a lower part b2 having a frustoconical cross-section. The air inlet nozzle A is in the form of a hollow tube extending from the inside of the main body B into the opening 9 of the source container 8. The nozzle A comprises a number of perforations ai to a_n with n being an integer greater than 1 , distributed along its length at equal distances. Additionally, a further perforation a_t is provided on the tip of the nozzle A. Air is injected into the nozzle A through an opening 4 in the upper part b1 of the main body B by means of an air inlet device 2 as depicted in Figures 3, 3a and 5.

This kind of configuration allows to form a vortex of blown air which facilitates the emptying of the source container 8 and, at the same time, fluidizes uniformly and more efficiently the particulate material, so that a downwardly directed flow of particles into the main body B of funnel 1 is formed.

The main body B has an upper part b1 having cylindrical cross-section and a lower part b2 having a frustoconical cross-section.

As shown in Fig.2 the particulate material flowing inside the funnel 1 is dispensed through a particulate suction opening 101 discharging into a sealable connection tip 102 extending outside the main body B.

The arrangement of perforations along the air inlet nozzle A is shown in Fig.4. Said perforations are distributed at equal distances from each other such that the distance between perforations a_n and a_n+i is always the same. In a preferred embodiment, the perforations are grouped in a number of four holes individuating a plane which is perpendicular to the longitudinal axis of the nozzle A. Fig.4a is a cross section along the aforementioned plane of holes and shows a further embodiment wherein an additional hole a_t is provided on the tip of the nozzle A. The air inlet device 2 of Fig.5 is connected to an air pump 15 provided with a control unit 16, which regulates the air pressure and the material flow. The flow of air between the pump 15 and the air nozzle 2 is secured by means of a one-way valve 20 positioned on the air conduct 21 as shown in Fig. 7, which prevents the flow-back of particulate material.

The air inlet device 2 is optionally provided with means 5 for the discontinuous insufflations of air, said means being preferably in the form of a spring engaged by a steel ball. This system allows to stop the flow of air into the air inlet nozzle A thus controlling more accurately the quantity of air and the insufflating time.

The internal walls of the frustoconical lower part b2 of the main body B may optionally show a pattern of curved grooves (not shown) radially converging into the middle of said lower part b2 in direction of the particulate suction opening 101.

The effect of the particular configuration of the perforations ai to a_n and/or a_t is the following: when particulate material fills the main body B, the powder tends to form agglomerates on the bottom and becomes more compact, with the risk of clogging and thus compromising the discharge process.

Compressed air is then pumped through the perforations ai to a_n in a direction which is perpendicular to the main body longitudinal axis. With the action of air, the particulate is therefore blown and fluidized, the agglomerates disrupted and the material is accelerated centrally in direction of the suction opening 101.

At this point, a uniform vortex of powder centered on the suction opening 101 and moving in direction of the main body lower part b2 is formed, wherein the particulate is accelerated longitudinally. Further collisions within the particulate material disaggregate the remaining agglomerates and the particulate material reaches the suction opening 101 where is then sucked inside by Venturi effect and thus discharged through the sealable connection tip 102. The flux of particulate material from the tip 102 can be interrupted simply by stopping the pumping of compressed air through the air inlet device 2. Tests performed with the additional presence of grooves on the internal walls of the lower part b2 have shown that the discharging of fluidized powder is more efficient and quick, due to the additional guidance provided by the radial configuration of the grooves, which allow the particulate powder to reach a higher tangential speed on exit.

As shown in Fig. 6 the system of the present invention may further comprise an adapter 6, which can be coupled to the main body B. This adapter 6 engages the main body B and is sealed to the source container 8 outlet opening 9 by means of the ring 7 (Fig. 6a). The adapter 6 allows to fit the air mixer funnel 1 to every kind of opening of a particulate source container, thus rendering the system according to the present invention a quick to set and universally applicable device. Making now reference to Fig. 7, to collect the discharged particulate in the destination container 14, the sealable connection tip 102 can be connected to a particulate discharge tube 12 which is fixed to an inlet opening 13 of said particulate destination container 14. In order to avoid unwanted leakage of powder when the filling operation has been stopped, the tube 12 comprises a discharge blocking system 121. When the adapter 6 is not used, the ring 7 seals directly the main body B to the opening 9 of the source container 8.

In addition to the system described above, the present invention provides also a method for filling particulate material from a source container 8 into a destination container 14.

The method comprises the following steps:

i. connecting an outlet opening 9 of the source container 8 with the air mixer funnel 1 as described above, wherein the particulate material flows inside the air mixer funnel main body B;

ii. fluidizing the particulate material in said main body B and/or in the source container 8 by blowing compressed air thorough the air inlet nozzle A;

iii. collecting the fluidized particulate material into the destination container 14.

Preferably, air is blown discontinuously through the air inlet nozzle A into the main body B and/or in the source container 8.

The system and the method described above can be applied to any kind of particulate material. Applicants have discovered that the present invention finds a very advantageous application for toner powders. Toner powders require in fact several precautions for their handling and use during recycling of exhausted laser printer cartridges by professional recyclers. A major problem has been identified in handling large containers (typically from 1 kg to 10 kg) to transfer the toner into smaller containers of preset weight to match the specific gram-fill required by each model of printer cartridge or to refill directly these cartridges with the correct amount of toner.

The physical characteristics of toner powders makes them easy to clog and stuck so that specific design, rather expensive and not easy to handle filling machines have been developed for dosing of these materials. The system described is a novel approach allowing the operator to transfer the toner directly from the large container into a cartridge or another smaller container with simple operation and lower costs. Brief description of the drawings

The main features of the invention and their advantages will be rendered more evident by referring to the appended drawings, which are intended as being merely explanatory and are therefore not limiting for the present disclosure.

They show:

Fig.1 : side view of the air mixing funnel 1 ;

Fig.2: cross-section of the lower part of the main body B;

Fig.3: cross-section of the cylindrical section b1 of the main body B showing the opening 4 and the connection with the air inlet nozzle A;

Fig.3a: cross section of the main body B perpendicular to the longitudinal axis;

Fig.4: longitudinal section of the air inlet nozzle A;

Fig.4a: cross section of the air inlet nozzle A perpendicular to the longitudinal axis;

Fig. 5: longitudinal section of the air inlet device 2;

Fig. 6: longitudinal section of the adapter 6;

Fig.6a: connection ring 7;

Fig.6b: connecting sleeve for ring 7;

Fig.7: schematic representation of the particulate filling apparatus according to the present invention;

Fig.8: a schematic view of the control unit 16 and air pump 15.

The opening 101 of Fig. 2 discharges into the sealable connection tip 102. The sealable connection of the tip 102 may be of any suitable shape, and may take advantage of known sealing profiles, including threaded portions and light friction fits. It may also take the form of a flat or contoured plate, or any shaped surface which corresponds with another surface to reduce leakage of dust particles during dispensing of particulate.

Fig. 6 is a longitudinal section of the adapter 6 which engages the air mixer main body B. The opening of a particulate material source container is connected with the upper part of the adapter, which is also provided with a protruding contoured profile 61 for engaging the ring 7.

Fig. 6a shows a side view of the ring 7 when it engages the outflow opening of a source container. Fig. 6b depicts a longitudinal section of the sleeve which allows the ring 7 to be connected to the adapter 6.

Fig. 7 provides a schematic view of the apparatus according to the present invention. A source container 8 in the form of a bag or a hopper of particulate material is hanged in a vertical position, so that the powder material flows in direction of the outlet opening 9. Here, the air mixer 1 according to the present invention is connected to said opening 9 through the adapter 6 and sealed with the ring 7. Compressed air is pumped by the air pump 15 and regulated by the control unit 16. The air flow is secured by means of the one way valve 20 which can open/close the flux by idle operations and prevents the particulate material flow-back.

The particulate discharge tube 12 connected to the sealable connection tip 102 and fixed to an inlet opening 13 of the particulate destination container 14 is provided with a discharge blocking system 121 which blocks the particulate flow. The discharge tube 12 and the system 121 are not restricted to particular materials or configurations. For instance, when the discharge tube 12 is a flexible silicone tube, the discharge blocking system 121 can be e.g. a pinch clamp. Fig. 8 offers a schematic representation of the control unit 16 comprising the built-in air pump 15. The control unit provides regulated power to a built-in air pump 15 (preferably 1 10 l/h capacity, 120 mbar max. pressure) connected to the air mixer funnel 1 through a tube 21. The unit is operated by one touch start/stop button 71 and provides selection means 74 for choosing continuous operation or intermittent operation depending on user requirements of flow and particulate characteristics. Additionally, it provides electronic adjustment of air flow power 73 and operating time adjustment 72 (e.g. from 10 sec. to 2.5 min.) to allow best fitting to each specific quantity requirement and to prevent excessive air overflow inside the destination container 14.

In addition to the above components, the apparatus of the present invention may also comprise weighing pre-dosage system to allow the in-line control of the amount of particulate discharged.

The operative conditions which have been applied during the process of filling of particulate have been optimized for minimizing both the time for filling the destination containers and the quantity of lost particulate at the end of the procedure. The best results have been obtained by applying inside the air mixer funnel 1 an air pressure of between 0.5 and 2.5 bar. The air has been blown discontinuously according to a "slow" or a "fast mode": the "slow mode" foresees a 5Hz frequency with a duty-cycle at 10%, whilst in the "fast mode" the frequency of blown air is at 10Hz with a duty-cycle of 10%. The duration of air impulses for the "slow mode" is 10ms ON and 190ms OFF, and for the "fast mode" is 10ms ON and 90ms OFF. For some toners it has been observed that the use of deionized air enhances the process of filling the destination containers since it increases and speeds up the fluidization of the particulate inside the air mixer funnel 1. Examples

The following examples show the values referring to the filling of different quantities of particulate into destination containers by use of the device according to the present invention. The source container contains for all the examples 10Kg of particulate to be transferred. In each table which sums up the results obtained by the filling procedure, the first column on the left indicates how many grams of particulate have been added to each destination container. The second column indicates the total number of containers which have been filled with the respective particulate quantity. In the column on the right it has been indicated the sum of the weight of particulate filled in all the containers of each kind.

Example 1

The first example relates to the filling process of 40 to 45g of particulate into destination containers. The source container contains 10 Kg of particulate.

Table 1 below reports the values obtained. Only 2.8% of the initial particulate quantity has been lost during the operations.

Table 1 Example 2

The second example relates to the filling process of 150 to 155g of particulate into destination containers. Table 2 below reports the values obtained. Only 2.5% of the initial particulate quantity has been lost during the operations.

Table 2

Example 3

The third example relates to the filling process of 300 to 305g of particulate into destination containers. Table 3 below reports the values obtained. Only 1% of the initial particulate quantity has been lost during the operations.

Table 3 Example 4

An analogous attempt made for filling toner quantities ranging between 90 and 95g from a source container of 10Kg has given the following results:

Table 4

During the filling operations only 1.9% of the initial toner quantity has been lost.

Results

From the above examples it is clear that the apparatus and method of the present invention provide a quick and reliable way of filling the destination containers with particulate in a reproducible, simple and cost-effective way, which can be adapted each time to the specific procedural needs as required by the volumes of the destination container used.

Claims

1 . System for filling particulate material from a source container (8) into a destination container (14), the system including an air mixer funnel (1 ) which comprises an air inlet nozzle (A) extending from the inside of a main body (B) of the funnel (1) into the source container (8), wherein said nozzle (A) is provided with perforations (ai) to (a_n) with n integer >1 , through which air flows inside the main body (B) and/or the source container (8).

2. System according to claim 1 ,

wherein the perforations (ai to a_n) of the air inlet nozzle (A) are positioned so that air flows in perpendicular directions with respect to the inlet nozzle longitudinal axis.

3. System according to claim 1 or 2,

wherein the air inlet nozzle (A) further comprises a perforation (a_t) on its tip.

4. System according to claim 1 ,

wherein the main body (B) has an upper part (b1 ) having cylindrical cross-section and a lower part (b2) having a frustoconical cross- section.

5. System according to one of claims 1 to 4,

further comprising an air inlet device (2) for insufflating air into the air inlet nozzle (A), coupled to the air inlet nozzle (A) through an opening (4) in the upper part (b1) of the main body (B).

6. System according to claim 5,

wherein the air inlet device (2) is provided with means (5) for the discontinuous insufflation of air.

t

7. System according to any one of the preceding claims,

wherein the lower part (b2) of the main body (B) comprises a particulate suction opening (101 ) discharging into a sealable connection tip (102) extending outside the main body (B).

8. System according to claim 7,

wherein the internal walls (3) of the frustoconical lower part (b2) of the main body (B) show a pattern of curved grooves (1 1) radially converging into the middle of said lower part (b2) in direction of the particulate suction opening (101).

9. System according to claim 7 or 8,

further comprising a particulate discharge tube (12) connected on one side to the sealable connection tip (102) of the air mixer funnel main body (B) and on the other side to an inlet opening (13) of the particulate destination container (14), wherein said tube (12) comprises a discharge blocking system (121 ).

10. System according to one of claims 5 to 9,

further comprising an air pump (15) provided with a control unit (16), said air pump (15) being connected to the air inlet device (2).

1 1. System according to one of the preceding claims,

wherein said particulate material is toner.

12. System according to any one of the preceding claims,

further comprising:

• an adapter (6) coupled with the main body (B) and

• a ring (7) engaging the adapter (6) or the main body (B) for connecting the air mixer funnel (1) with an outlet opening (9) of the particulate source container (8).

13. Method for filling particulate material, preferably toner, from a source container (8) into a destination container (14), comprising the following steps:

iv. connecting an outlet opening (9) of the source container (8) with an air mixer funnel (1) according to one of claims 1 to 10, wherein the particulate material flows inside the air mixer funnel main body (B);

v. fluidizing the particulate material in said main body (B) and/or in the source container (8) by blowing compressed air thorough the air inlet nozzle (A);

vi. collecting the fluidized particulate material into the destination container (14).

14. Method according to claim 13,

wherein air is blown discontinuously through the air inlet nozzle A into the main body (B) and/or in the source container (8).

15. Use of a system according to one of claims 1 to 12 for filling toner.