DK151175B - PROCEDURE FOR SOLVING POWDER IN A VOLUME VOLUME AND APPARATUS FOR EXERCISING THE PROCEDURE - Google Patents

Description

151175 i

The invention relates to a method of dissolving a portion of rapidly soluble powder, e.g. coffee powder, in a volume of liquid which exhibits a relatively large surface in a mixing chamber. The mixing chamber is typically included as a component of a machine for automatically mixing said media, e.g. a coffee machine.

For example, US Patent No. 3,300,094 discloses a coffee machine adapted to mix a predetermined amount of hot water and a predetermined amount of coffee powder to produce a cup of coffee when a coin is tossed into apparatus. Said as well as other known devices have the disadvantage that an effective solution of the powder in the water takes a relatively long time (typically 5 seconds for a cup of coffee) due to the methods used to introduce the two media into the mixing chamber. Typically, the powder is conveyed by means of a auger and descends into the mixing chamber while the water is introduced as a jet into the chamber.

The object of the invention is to provide a process 20 of the kind in which a substantial reduction of the time required for dissolving the powder in the water is obtained, especially by dissolving individual portions (eg 1 cup of coffee). This object is achieved by the practice of the characterizing part of claim 1, since it has been found that in this technique a single cup of coffee can be mixed in about 10 minutes.

1 second. This technique is based on an improvement in the process known from Norwegian patent No. 62 000, from which it is known to dissolve powder in water by imparting a large surface area to the water and distributing the powder over that surface.

It will be appreciated that in the case of a hot beverage, the water will be almost boiling, so that due to the large water surface in the mixing chamber, a relatively large amount of steam will be released. It is well known that steam is a disadvantage in that moisture can be deposited especially around the means for dispensing the coffee powder so that these agents are clogged. From the aforementioned US patent, there is known a method for venting the mixing chamber so that the humid air is sucked out through the bottom of the mixing chamber and does not come close to moisture-sensitive parts of the apparatus.

The invention is thus based partly on the recognition that the vent can be made so effective that the large water surface required in the process does not cause any disadvantages, but only brings about the advantage known per se in the Norwegian patent, and partly that the dosing technique known from the Norwegian patent cannot be put into practice when small powder portions have to be dissolved individually. More specifically, in the prior art, it is not possible to disperse a small portion of powder both quickly and uniformly, since a spread usually exhibits a non-reproducible initial course. By utilizing precisely the flow of air through the mixing chamber, which is generally known from the aforementioned US patent, to assist in controlling and spreading the powder, it has been found that a rapid and uniform distribution of a small amount of powder can be obtained, thus that, by combining the above mentioned techniques and utilizing the controlled air's controlling effect on the distribution of the powder, a surprisingly good result is obtained.

Claim 2 specifies preferred details for producing the known extensible fluid layer. If several cups of coffee are to be mixed consecutively, the water may possibly flow evenly through the mixing chamber, but in all cases it is a prerequisite for the invention that the powder is delivered intermittently. Precisely in this mode of operation, which is a prerequisite for mixing a single cup of coffee, a substantial reduction of the mixing time is obtained, and the reduction of the mixing time in relation to the prior art is so great that an apparently continuous mixing (in the preparation of many cups of coffee) can be provided at a rapid range of intermittent dosages according to the invention.

The invention further relates to an apparatus for carrying out the method and of the nature specified in the preamble of claim 4.

The apparatus is peculiar to the features specified in the characterizing part of claim 4 which, in combination, cause the surprising effect explained above. The mixing chamber typically has the shape of a flat bottomed vessel, which will be discussed later, but could also be shaped like a trough such that the bottom of the mixing chamber is cylindrical or spherical. The design of the bottom of the mixing chamber is, in principle, limited only by the possibility of supplying liquid such that for a moment a relatively thin layer of liquid covering the bottom of the mixing chamber is provided and is limited by the fact that it is possible to spread the powder evenly over the liquid surface. by means of the distributive effect of the air flow on the powder.

The means for introducing the liquid are preferably designed as claimed in claim 5, while claim 6 indicates preferred details of the mixing chamber according to the invention. In practice, it has been found that the uniform drop mentioned in claim 6 can be designed such that a relatively thin, coherent liquid layer is obtained over the entire bottom of the mixing chamber. In claim 7, a preferred embodiment of the means for dispensing the powder is stated.

These agents are a further development of a dosing means known per se, which is set forth in the preamble of claim 7. Thus, it is achieved that the powder is delivered effectively in a very short time, where delivery can be made particularly effective by forming the cavity of the dosing means. as claimed in claim 8, in which this particular structure cooperates well with the controlling effect of the air flow on the dispersion of the powder. It will be appreciated that there may be one or more cavities in a single cylinder, and that two or more cylinders may be used simultaneously in connection with the fact that the area of the bottom of the mixing bowl 15 can be increased correspondingly and in connection with the intake openings. for the air flow through the mixing chamber is expanded to continue to ensure uniform, instantaneous distribution of the powder.

Advantageously, the mixing bowl may be provided with the intermediate chambers mentioned in claim 20 9, which have an upwardly facing opening in use. During operation, the latter opening will be located under a stud through which the aforementioned quantity of liquid is dispensed, e.g. from a reservoir, thereby obtaining the advantage that the mixing chamber can be withdrawn as a unit of the apparatus for cleaning or eventual replacement. The mixing chamber can again be introduced into the apparatus by a simple operation so that in the preferred embodiment, it is not necessary to connect it with hoses for water supply, suction or the coffee outlet.

Claim 10 specifies a convenient design of the apparatus for carrying out the method, thereby obtaining at the same time an effective "blanket" of dry air around the dosage cylinder itself.

In a preferred embodiment of the location of the suction openings, these are arranged as a pair outside the rows of 5 holes located in claim 10, cf. the following description.

The invention will be further explained by the following description of a preferred embodiment, reference being made to the drawing, in which: 1 is a schematic view of a coffee machine provided with a blending unit according to the invention; FIG. 2 and 3. shows a section through a preferred embodiment of a mixing unit, while FIG. 4- and 5 show corresponding sections for understanding the operation of the apparatus.

The invention will now be explained in connection with a coffee machine of the embodiment shown in FIG. 1 art. The coffee machine comprises a cabinet 1 which externally has a coin drawer 2 and an opening 3 for receiving a mug 4 for receiving hot coffee from the machine.

20 At 5, a limb is provided which allows the vending chamber of the dispenser, which will be described later, to be withdrawn from the dispenser.

In FIG. 1, the principally important components are also shown inside the cabinet 1. These components comprise a water container 6 and a coffee powder container 7. The water and coffee powder are mixed in an aggregate 8 which can be withdrawn through the limb 5 and which at the rear communicates with a suction manifold 9 which is connected to a fan via a hose 10. The purpose 30 of the fan is to extract water vapor from the unit. 8, 6, air being drawn in through the air in FIG. 1, which air according to the invention is utilized to influence the dispersion of powder from a powder magazine and is sucked through the assembly 8, where the air is mixed with water vapor, after which the mixture is blown out through a hose 13. Finally, at 14 a box containing the electrical control circuits for the vending machine.

More particularly, the invention relates to the mixer assembly 8, and thus the invention is not dependent on that of FIG. 1 illustrates a coffee machine. Eg. for use in restaurant kitchens, the coin insert 2 will be replaced by a button for e.g. selecting the desired number of cups of coffee, the opening 3 being sufficiently large to accommodate a coffee pot. In large kitchens 15, certain parts, e.g. the water container, the fan and the electric control circuits are common to several mixing units 8, which can be understood by the following explanation of a preferred embodiment of the mixing unit 8 with associated coffee container 7.

20 In connection with FIG. 2 and 3. the constructive design will first be explained, after which the operation of the apparatus will be explained by the following figures. Figures 2,4 and 3,5 show sections along the lines 11 - 11 and III - III respectively.

As can be seen from the figures, the mixing unit 8 comprises a housing 15 containing a collection funnel 16 and a mixing chamber 17, which parts are preferably composed of blow molded or injection molded plastics. The collecting funnel 16 rests on some support legs 18 in the housing 15, 30 and the mixing chamber 17 has the shape of a vessel having a circumferential flange 19 in its operating position, the outer edge of which rests against a bent edge of the upper edge of the housing 15. Said edges fit into a groove in a pair of rails 20, 21 which are secured to the underside 7 of the container 7 so that the mixing unit 8 can be pulled out as a drawer, e.g. when cleaning the mixer. The mixing chamber 17 is connected to an intermediate chamber 22, which has an upward opening 23, and communicates with the mixing chamber 17 via a narrow slot 24. In the operating position, the opening 23 is flush with a hose 26 which is connected via a magnetic valve 27 with the water tank 6.

The container 7 comprises a coffee powder magazine, the bottom 10 of which comprises a pair of opposed sloping walls 28, 29 which, by means of gaskets not shown, close close to the surface of a rotatable metering cylinder 30. Under each of the sloped walls 28, 29 there is provided a substantially closed cavity by means of a screen plate 31, which 15 cavity serves as an intake manifold for air drawn through the mixer and out of the extraction manifold 9 via a filter 32. The air is sucked in through holes 33, 34 and down into the mixing chamber 17 via some holes. 35A and 35B and a pair of narrow slots 36A and 36B defined 20 between the screen plate 31 and the metering cylinder 30. Thereafter, the air flows out through a slot 37 in the bottom of the mixing chamber 17 and out of the filter 32, there being an air passage between the mixing chamber 17 and the collection funnel. 16. The air can advantageously be sucked in 25 via hoses 42 which are connected to a jacket 43 in direct heat conductive contact with the water container 6, whereby the suction the air can be preheated by passage through the chamber 43 so that the air flow through the slot 36, in addition to the later explained powder controlling effect, provides a protection against condensation being deposited on the metering cylinder 30.

The metering cylinder 30 has a shaft which is housed in a pair of opposite walls of the container 7 and which, on one side, is provided with a sprocket 38 which is engaged by a sprocket 39 in an actuating mechanism 8. The mechanism 40 is arranged to be able to rotate the cylinder 30 half a turn, whereby the coffee powder contained in a longitudinal slot 41 in the dosing cylinder is delivered to the mixing chamber 17. The powder 5 can thus be dispensed quickly in small portions (corresponding to e.g. cup of coffee), which so far has not been able to be combined with an even distribution of the powder portion over the liquid surface. By utilizing the air flow through the mixing chamber of the invention to influence the powder distribution, it is now possible to distribute small powder portions intermittently and very evenly over the liquid surface.

The operation will now be explained in more detail on the assumption that a single cup of coffee must be produced. The first thing that happens is that the solenoid valve 27 opens up for a predetermined period of time, so that the intermediate chamber 22 is quickly filled with hot water, e.g. 95 ° C. From the intermediate chamber 22, the water will flow through the slot 24 and into the bottom of the mixing chamber 17, which inclines such that it exhibits a fall away from the slot 24 and partly a fall towards the slot 37. The slot 24 is defined by height adjustable angle rail 44 such that the entire bottom of the mixing chamber is covered for a short time by a thin layer of water. In FIG. 4 and 5, the situation is shown where all the water has not yet flowed out of the intermediate chamber 22. When all the water has flowed out of the intermediate chamber and, as previously mentioned for a short moment, covers the entire bottom of the mixing chamber, the drive mechanism 40 is activated so that the metering cylinder 30 is quickly 30 is rotated half a revolution to that of FIG. 4, whereby a predetermined amount of coffee powder indicated at 47 is dispensed which, under the influence of the air flow through the mixing chamber, is uniformly distributed in the form of a thin layer over the water surface covering the entire bottom of the mixing chamber. In this method, the powder dissolves practically instantaneously and before the water, as a result of the sloping bottom of the mixing chamber, flows out through the slot 37 and down into the collection funnel 16, from which it is led to an outlet opening 45, which in the position of use is located vertically above the position shown in FIG. 1 mug 4.

By means of the shield plate 31, the air flow is controlled to assist in the desired uniform distribution of the coffee powder over the bottom of the mixing chamber, partly as a result of the slots 36A and 36B, whereby the air flow through them simultaneously ensures condensation on the dosing cylinder 30, and partly through the two rows of holes 35A and 35B extending parallel to the metering cylinder 30. It will be appreciated that some water vapor is released into the mixing chamber 17 due to the large surface area of the water, which, however, presents no problems at all. due to the described effective air flow shown by arrows in FIG. 4 and 5.

It should also be noted that the plane of the gap 37 is inclined with respect to the bottom of the mixing chamber 17, which thereby exhibits a lip 46. This deflects the flow of air through the gap 37 to the side (to the left of FIG.

2 and 4), which causes the water leaving the lower edge of lip 46 to be initially unaffected by the air flow and falls down as a "water-curtain" at least to such an extent that it effectively prevents coffee powder is dispensed from the metering cylinder 30 directly through the slot 37 without this coffee powder being in contact with the water.

The embodiment described above has a further advantage, namely that the mixing chamber is very easy to remove from the apparatus in case of cleaning or replacement.

Referring to FIG. 4, the housing 15, the collecting funnel 16 and the mixing bowl 17 are extrudedly placed in the rails 10, 21, and it is therefore essential that the intermediate chamber 22 (Fig. 3) is located below the hose 26 which is in the position of use vertically above the opening 23 in between the chamber. Also, it is important that the suction manifold 9 is arranged to receive the rear open end of the housing 15, which in the operating position is airtightly enclosed by a circumferential collar 48 on the suction manifold 9. As can be seen in the figures, the filter 32 can be arranged in it. said open end of the housing 15, thereby obtaining 10 the advantage that the filter can also be cleaned or replaced when the housing 15 is pulled out of the apparatus.

Claims (10)

Patent Claims: A process for dissolving a portion of rapidly soluble powder, e.g. coffee powder, in a volume of liquid which exhibits a relatively large surface area in a mixing chamber, characterized in that the powder is dispensed 5 and dispersed by intermittent operations and that an air flow necessary for a known liquid suction is introduced into the mixing chamber (17) such that the air flow contributes to an even distribution of the powder over the liquid surface. Method according to claim 1, characterized in that a mixing chamber (17) is used, the bottom of which has a relatively large surface area in relation to said liquid volume and that the liquid is introduced rapidly from at least one of the sides of the mixing chamber (17) so that mixing chamber The bottom of the 15 mer (17) is covered by a continuous liquid layer for a predetermined period of time, during which the powder is uniformly spread uniformly over the liquid layer. Process according to claim 2, characterized in that the predetermined amount of liquid is discharged portionwise corresponding to an operation for spreading the powder. An apparatus for carrying out the method according to claim 1, comprising a mixing chamber (17) adapted to receive a volume of liquid as well as an amount of rapidly soluble powder, e.g. a coffee powder and 25 containing liquid vapor extraction means, characterized in that the bottom of the mixing chamber (17) has a relatively large surface area in relation to said liquid volume and that means (22-24) are known per se way of introducing the liquid into the mixing chamber (17) in the form of a relatively thin layer of liquid which substantially covers the bottom of the mixing chamber (17) for a predetermined period of time and means (30) are provided for dispense and disperse the powder over the liquid layer during an operation within said time period, and 5 include in the mixing chamber suction openings (35A, B, 36A, B) for the amount of air vapor required for suction of liquid vapor, which openings are positioned so that the inflowing air contributes to an even distribution of the powder over the liquid surface. Apparatus according to claim 4, characterized in that the means for introducing the liquid comprise a narrow slot (24) located along at least one of the confining sides of the mixing chamber (17) and flush with the bottom of the mixing chamber. Apparatus according to claim 5, characterized in that the bottom of the mixing chamber (17) is substantially flat and rectangular, and that a single slot (24) is provided along one side edge for introducing the liquid into the mixing chamber, and that in the mixing chamber bottom, an oblong gap (37) located transversely of said side edge is provided for discharging the liquid containing dissolved powder, the bottom of the mixing chamber exhibiting an even decrease in directions partly perpendicularly away from the slit and partly perpendicular to the gap. Apparatus according to claim 4, wherein the means for dispensing the powder comprises at least one cylinder (30) rotatable about its axis, which is located above the mixing chamber and closes an opening at the bottom of a funnel (28, 29) containing the powder, which cylinder has at least one 30 cavity which is open to the surface of the cylinder and which can be caused to rotate within and outside the hopper, respectively, by turning the cylinder, characterized in that the bottom of the mixing chamber is rectangular and that the cylinder and associated cavity extend over the mixing chamber substantially over its full length. Apparatus according to claim 7, characterized in that the cavity extends parallel to a diametral plane of the cylinder at a distance from this plane. Apparatus according to any one of claims 4-8, characterized in that the mixing chamber is connected 10 with an intermediate chamber (16) located outside the bottom of the mixing chamber, which communicates with the mixing chamber via said slot (37) or slots, and that the middle chamber has an upwardly facing opening in use. Apparatus according to any one of claims 7-9, characterized in that a shield plate (31) parallel to the axis of the cylinder (31) is provided between the hopper and the mixing chamber, which has a slot for receiving the lower part of the cylinder so that a narrow gap 20 (36A, 36B) for suctioning air into the mixing chamber is provided between the cylinder and the edges of the slot.