EP1452223A1

EP1452223A1 - Mixing device and method for mixing products applying such a mixing device

Info

Publication number: EP1452223A1
Application number: EP04075579A
Authority: EP
Inventors: Jan M. L. Vercammen
Original assignee: Egemin NV
Current assignee: Egemin NV
Priority date: 2003-02-25
Filing date: 2004-02-24
Publication date: 2004-09-01
Also published as: BE1015384A3

Abstract

Mixing device for the continuous in-line mixing of a granulated material (2), in particular a powder, in a liquid (3), characterised in that it mainly consists of an injector-type mixer (4) with at least one injector-shaped feed-through duct (5) for the liquid (3) and at least one supply duct (6) for the granulated material (2) connected onto it on the one hand, whereby a continuously controlled dose-measuring element (7) is provided between the above-mentioned supply duct (6) and the supply element (8), which is provided with a control element (12), for the continuous supply of a controlled mass flow of the granulated material (2) from the supply element (8), in order to obtain a required mass ratio at the outlet of the injector-type mixer (4).

Description

The present invention concerns a mixing device and a method for mixing products applying such a mixing device.
In particular, the invention aims a mixing device for mixing a granulated material, in particular a powder, in a liquid.
Mixing processes whereby a granulated material, in particular a powder, must be mixed in a liquid, are used in a large number of fields. An important field here is the food sector, for mixing food products.
What is important hereby, is that a mixed product is finally obtained with a certain mass ratio.
In practice, especially in the food sector, use is often made of an injector-type mixer to this end with at least one injector-shaped feed-through duct for the liquid and at least one supply duct for the granulated material connected onto it. Onto the supply duct is connected a funnel-shaped tube in which, while the liquid flows through the injector-shaped feed-through duct, the granulated material is poured in manually. Thanks to the underpressure created in the injector, the granulated material is then sucked into the liquid.
It is known that with this mixing technique, no constant mass ratio can be guaranteed at the outlet of the mixer.
In order to nevertheless obtain the required mass ratio in the end product, a mixing tank is provided after said mixer, and the proceeding takes place in batches by each time putting a certain mass of granulated product in a certain amount of liquid, whereby one also makes sure that the mixing is at least so much faster in the above-mentioned mixer that the granulated product is used up entirely before all the liquid of the above-mentioned mass has flown through the mixer. Next, there is a re-mixing in the mixing tank, as a result of which a uniform mass ratio is obtained for the total amounts.
This known technique is disadvantageous in that a usually voluminous mixing tank is required on the one hand, and one can only proceed in batches on the other hand, which, as is known, has several disadvantages compared to a continuous in-line process.
The present invention aims a mixing device having good mixing qualities and which makes it possible, among others, to exclude the above-mentioned disadvantages of the known techniques.
To this end the invention, according to a first aspect, provides a mixing device for the continuous in-line mixing of a granulated material, in particular a powder, in a liquid, which mixing device mainly consists of an injector-type mixer with at least one injector-shaped feed-through duct for the liquid and at least one supply duct for the granulated material, which supply duct (6) is connected onto a supply element for the granulated material (2) whereby a continuously controlled dose-measuring element is provided between the above-mentioned feed-through duct and the supply element, which is provided with a control element, for the continuous supply of a controlled mass flow of the granulated material from the supply element. This combination of characteristics offers the advantage that a very precise dose measuring of the granulated material in the above-mentioned mixer becomes possible, such that a better controlled mass ratio, and also a more uniform mixing is obtained.
The controlled dose-measuring element preferably consists of a controlled valve, allowing for a very accurate dose measuring of the granulated material in a smooth manner.
More in particular, a pulse-controlled valve is preferably applied, whereby the pulses provide for example for a movement of the above-mentioned valve between at least two positions, and preferably between an open and a closed position. The use of such a pulse-controlled valve offers the advantage that the granulated material is subjected to vibrations at least at the valve, preventing the granulated material from coagulating, as a result of which the supply could be interrupted.
According to the most preferred embodiment, the above-mentioned valve comprises a conical valve disc, whereby the granulated material is supplied as of the top side of the above-mentioned valve disc. Such a valve helps to prevent coagulation and allows for a very accurate dose measuring.
More in particular, a valve is preferably applied which is marketed under the brand name SEMENENKO VALVE, which type of valve is also described in American patent No. 6,341,715.
The above-mentioned supply element preferably consists of a container, in particular a silo. The controlled dose-measuring element, i.e. in particular the above-mentioned valve, is then preferably situated at the bottom in the outlet opening of the container or silo.
According to a major preferred characteristic, the above-mentioned injector-type mixer is connected onto the above-mentioned supply element via an air-tight, in other words a vacuum connection. Such an air-tight or vacuum connection offers the advantage that larger inclusions of air in the granulated material between the supply element, i.e. the silo, and the injector-type mixer are excluded, such that a continuous supply of a constant mass flow of granulated material to the mixer can be guaranteed with great certainty.
The mixing device preferably also comprises a controlled dose-measuring element for the liquid supplied to the injector-type mixer, such as for example a metering pump. This offers the advantage that the supply of the granulated material as well as the liquid supply can be controlled via a control unit, and that a required mass ratio can be set at any time.
It should be noted that the combined use of two controlled dose-measuring elements, for the supply of the granulated material, for example powder, and for the liquid respectively, is also particularly advantageous for mixing a granulated material in a liquid, in combination with other mixers than the above-mentioned injector-type mixer. For, thanks to this combined use is also obtained an arrangement allowing for a very well controlled mixing, which makes it possible, for example, to realise a continuous in-line mixing without any mixing tank or the like being further required.
According to a second aspect, the present invention also provides a mixing device for the continuous in-line mixing of a granulated material, in particular a powder, in a liquid, which mixing device at least consists of the combination of a mixer in which the granulated material and the liquid are brought together; a first controlled dose-measuring element via which the liquid is supplied to the mixer; and a second dose-measuring element controlled by a control element via which the granulated material is supplied to the mixer with a controlled mass flow.
Further, the invention also concerns a method for the continuous in-line mixing of products, whereby a granulated material, in particular a powder, is mixed in a liquid, characterised in that one of the above-mentioned mixing devices of the invention is applied to this end. As mentioned above, this method is particularly useful to realise an in-line mixing, whereby such in-line mixing is preferably realised without any buffer action or re-mixing.
Although the invention can be applied in all sorts of fields, it is particularly advantageous for mixing food products.
In order to better explain the characteristics of the invention, the following preferred embodiments are described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:
figure 1 represents a mixing device according to the invention, partially schematically represented;
figure 2 represents another embodiment of a mixing device according to the invention, further schematised.
As represented in figure 1, the invention concerns a mixing device 1 for mixing a granulated material 2, in particular a powder, in a liquid 3.
This mixing device 1 at least consists, as is represented, of an injector-type mixer 4 with at least one injector-shaped feed-through duct 5 for the liquid 3 and at least one supply duct 6 for the granulated material 2 connected onto it on the one hand, and a supply element 8 for the granulated material 2 connected onto the above-mentioned supply duct 6 via a controlled dose-measuring element 7 on the other hand.
The controlled dose-measuring element 7 consists of a controlled valve, having a valve disc 10 which can be moved by means of a drive element 9. This controlled valve is preferably pulse-controlled, whereby the pulses provide for example for a control between an open and a closed position. These open and closed positions are obtained for example as the valve disc 10, as indicated by the arrow in figure 1, can be moved up and down, whereby a circular passage 11 is formed around the valve disc 10 in open position. The control takes place by means of a control unit 12 which provides for the necessary control signals, possibly as a function of different parameters, such as sensor data and the like.
According to a variant which is not represented here, the valve disc 10 can also be controlled in another way. Further, use can be either or not made of an additional vibration mechanism which is not represented here in order to prevent the granulated material 2 from coagulating and thus its supply from being blocked.
As represented, the dose-measuring element 7 preferably comprises a conical valve disc 10, in particular a valve disc 10 with a conical top side 13.
In the given example, the above-mentioned supply element 8 consists of a container, in particular a silo, which narrows at the bottom towards an outlet opening 14, whereby the above-mentioned dose-measuring element 7 is situated at said outlet opening 14.
The mixer 4 is connected to the above-mentioned supply element 8 via an air-tight connection 15.
In the given example of figure 1, the mixing device also comprises a controlled dose-measuring element 16 for the liquid 3, in this case in the shape of a metering pump which is also controlled by the control unit 12.
The working of the mixing device 1 from figure 1 can be easily derived from the figure and the preceding description, but it will be briefly explained hereafter for clarity's sake.
Via the dose-measuring element 16, liquid 3 is forced through the mixer 4 in a dosed manner, i.e. with a certain flow rate, in particular through its feed-through duct 5 embodied as a jet nozzle. The dose-measuring element 7 is simultaneously controlled in an appropriate manner by the control element 12, such that a certain mass flow of granulated material 2 goes through the passage 11, which is systematically sucked along with the liquid 3 via the connection 15 and the supply duct 6. In this manner, a controlled in-line mixing becomes possible, whereby fixed mass ratios at the outlet of the mixer 4 can be guaranteed.
It should be noted that the dose-measuring element 16 is not strictly necessary and that it will be either or not used as a function of the necessity thereof. For it is not excluded to supply the liquid 3 to the mixer 4 at a constant, known flow rate, whereby the dose-measuring element 7 will then be controlled accordingly. There could also be a flow measurement in the liquid supply which is then used to control the dose-measuring element 7 in proportion to the measured flow rate.
Figure 2 represents a more developed embodiment of a mixing device 1 according to the invention, whereby parts of the same name are indicated with the same reference numbers.
Apart from the parts which have already been described by means of figure 1, the mixing device 1 of figure 2 comprises at least one additional mixer 17 of the in-line continuous type, downstream of the mixer 4. Via this mixer 17 can be obtained a further homogenisation of the mixture, at least if this would still be necessary.
The additional mixer 17 is preferably of what is called the high shear type. In particular, this mixer 17 preferably has a polygonal mixing chamber, in which are situated fast rotating stirring elements accomplishing shearing forces. Such a type of mixer 17 is for example marketed under the brand name 'TYPHOON high shear in-line mixer' of the company TYPHOON ROERTECHNIEK B.V. from the Netherlands.
As is represented, a supply line 18 can be connected to the additional mixer 17 in order to dose additional components, for example by means of a metering pump 19.
Further, the device 1, as is represented, can be equipped with the necessary sensors 20 working in conjunction with a control unit 21, by means of which the homogeneity can be controlled. This control unit 21 can possibly provide data with which the above-mentioned control unit 12, which is not represented in figure 2 however, can be controlled in an appropriate manner.
Further, use can be made of additional pumps, such as the pump 22, in order to maintain the required pressure in the circuit.
The working of the mixing device 1 from figure 2 is mainly similar to that in figure 1, with this single difference that a re-mixing takes place in the mixer 17.
It is clear that different variants are possible. Thus, for example, the supply element 8 must not necessarily be formed of a fixed silo, but it may be formed of any container-shaped element whatsoever, for example also of a flexible container bag or the like which is provided with a discharge opening at the bottom and which is connected to a dose-measuring element 7 via this opening.
Depending on the application, the mixing device 1 according to the invention can offer several advantages, a number of which will be summed up hereafter:

The mixing device 1 can be built in in a transfer line, in other words it can be implemented in an existing production line, as no special room has to be provided for mixing tanks.
Such a mixing device 1 can be cleaned in-line.
Mixing by means of a one-off flow-through principle is possible.
The granulated material 2 can be supplied in an automatic, dustproof and vacuum-resistant manner without any intervention of an operator. Hence, the risk of an operator getting into contact with the granulated material 2 when shaking out bags containing this material 2, as used to be the case, is excluded now, which is of major importance in a large number of applications, since frequent contact with certain materials 2 often causes allergies.
By using a vacuum-tight connection 15, also the formation of foam can be excluded, as no large inclusions of air can be sucked into the liquid 3.
The component parts, such as the injector-type mixer 4 and the additional mixer 17 can be easily exchanged, such that when recipes are adapted, whereby other mixing characteristics are aimed at, one does not need a new equipment.
The mixing device 1 can be made compact.
The mixing device 1 does not need start-up or preparation tanks.
The mixing device 1 allows for a continuous mixing, such that a batch process can be excluded.
In case the entire powder content has been dosed, it is possible to obtain a complete sealing by means of the dose-measuring element 7, such that air being sucked into the liquid 3 can be at all times excluded, so that the formation of foam is avoided or at least minimised.

The present invention is by no means limited to the above-described embodiments given as an example and represented in the accompanying drawings; on the contrary, such a mixing device and the above-mentioned method can be made according to different variants while still remaining within the scope of the invention.

Claims

Mixing device for the continuous in-line mixing of a granulated material (2), in particular a powder, in a liquid (3), characterised in that it mainly consists of an injector-type mixer (4) with at least one injector-shaped feed-through duct (5) for the liquid (3) and at least one supply duct (6) for the granulated material (2) connected onto it, which supply duct (6) is connected onto a supply element for the granulated material (2) whereby a continuously controlled dose-measuring element (7) is provided between the above-mentioned supply duct (6) and the supply element (8), which is provided with a control element (12), for the continuous supply of a controlled mass flow of the granulated material (2) from the supply element (8), in order to obtain a required mass ratio at the outlet of the injector-type mixer (4).
Mixing device according to claim 1, characterised in that the controlled dose-measuring element (7) consists of a controlled valve.
Mixing device according to claim 2, characterised in that the controlled valve is provided with a vibration mechanism.
Mixing device according to claim 2 or 3, characterised in that the controlled valve is pulse-controlled, whereby the pulses preferably provide for a control between an open and a closed position.
Mixing device according to any of claims 2 to 4, characterised in that the valve has a conical valve disc (10).
Mixing device according to any of claims 2 to 5, characterised in that a valve is applied which is marketed under the brand name SEMENENKO VALVE.
Mixing device according to any of the preceding claims, characterised in that the above-mentioned supply element (8) consists of a container, in particular a silo.
Mixing device according to any of claims 1 to 6, characterised in that the above-mentioned supply element (8) consists of a silo which narrows at the bottom towards an outlet opening (14), whereby the controlled dose-measuring element (7) is situated in said outlet opening (14).
Mixing device according to any of the preceding claims, characterised in that the above-mentioned mixer (4) is connected to the above-mentioned supply element (8) via an air-tight connection (15).
Mixing device according to any of the preceding claims, characterised in that it also comprises a controlled dose-measuring element (16) for the liquid (3).
Mixing device according to claim 10, characterised in that the controlled dose-measuring element (16) for the liquid (3) consists of a metering pump.
Mixing device according to any of the preceding claims, characterised in that at least one additional mixer (17) of the in-line continuous type is provided downstream of the aforesaid mixer (4).
Mixing device according to claim 12, characterised in that the additional mixer (17) is of what is called the high shear type.
Mixing device according to claim 13, characterised in that the additional mixer (17) is of the type which has a polygonal mixing chamber, in which are situated fast rotating stirring elements accomplishing shearing forces.
Mixing device according to any of claims 12 to 14, characterised in that a supply line (18) for dose-measuring additional components is connected to the additional mixer (17) .
Mixing device for the continuous in-line mixing of a granulated material (2), in particular a powder, in a liquid (3), characterised in that it at least consists of the combination of a mixer (4) in which the granulated material (2) and the liquid (3) are brought together; a first controlled dose-measuring element (16) via which the liquid (3) is supplied to the mixer (4); and a second dose-measuring element (7) controlled by a control element (12) via which the granulated material (2) is supplied to the mixer (4) with a controlled mass flow.
Method for the continuous in-line mixing of products, whereby a granulated material (2), in particular a powder, is mixed in a liquid (3), characterised in that a mixing device according to any of the preceding claims is applied to this end.
Method according to claim 17, characterised in that it is used to realise an in-line mixing, without any buffer action or re-mixing.
Method according to claim 17 or 18, characterised in that it is used for mixing food products.