EP1832547A1

EP1832547A1 - Tap for carbonated drinks, equipped with a perfected compensator

Info

Publication number: EP1832547A1
Application number: EP06126136A
Authority: EP
Inventors: Domenico Tonati
Original assignee: TOF Srl
Current assignee: TOF Srl
Priority date: 2006-03-10
Filing date: 2006-12-14
Publication date: 2007-09-12
Also published as: ITMI20060086U1

Abstract

This invention relates to a tap of the type used for dispensing carbonated drinks, equipped with a perfected compensator designed to limit froth formation during dispensing.
Said tap, which is of the type designed to dispense carbonated drinks, equipped with a compensator (5) designed to limit froth formation during dispensing, said compensator (5) having a cone frustum shape which is inserted into the flow of the drink dispensed in such a way that said drink flows through an annular channel, contained between the outer walls of said conical compensator (5) and a pipe (4) which contains said compensator (5), which said compensator (5) includes at least one pair of channels (14, 14a), that lead from the outer surface of said compensator (5) to an axial channel (16) in the body of said compensator (5), and which said compensator (5) includes a recess (17) into which head (8a) of a gate valve (8) is at least partly inserted, is characterised in that said channel (16) has a cross-sectional shape such that the ends of said channel (16) are not covered by said head (8a) of said gate valve (8), the shape of said channel (16) being such that the cross-sectional area has a length a greater than the diameter of said head (8a) of said gate valve (8), so that at least part of the drink flows directly, without encountering any obstacles that substantially divert its flow.

Description

This invention relates to a tap of the type used for dispensing carbonated drinks, equipped with a perfected compensator designed to limit froth formation during dispensing.
Taps of this kind present the problem of limiting the turbulence of the liquid flow while the drink is being dispensed. Especially in the case of beer, turbulence generates great deal of undesirable froth in the presence of dissolved gases.
To considerably reduce turbulence, the prior art requires the drink to flow through a pipe into which a device known as a compensator, with a cone-shaped part, is inserted. In practice the pipe is cone-shaped, with a diameter that increases in the direction of flow and a conicity substantially equal to that of the compensator inserted in said pipe. This forms a toroidal pipe between the pipe walls and the walls of the compensator device. When the compensator is moved axially in relation to the pipe, the cross-sectional area through which the drink flows, and consequently the flow of the drink, is varied.
The compensator device usually also includes a cylindrical part, coaxial with said conical part, which has the function, in association with the inner walls of the pipe, of guiding the axial movement of the compensator, which said movement is obtained via an eccentric bolt, controlled by a lever external to the body of the tap, which is inserted into a recess on the side of said compensator, usually on the cylindrical part.
The drink consequently flows through said toroidal section of the pipe, and is then conveyed into two or more channels which begin on the outer surface of the conical part of the compensator, which said channels lead into an axial pipe that leads to a subsequent section of the tap, fitted with the gate valve that controls the flow of the drink.
The problem presented by the compensators according to the prior art is that they do not completely eliminate turbulence from the flow. For this reason, numerous forms of said compensators have been designed over the years, all substantially consisting of a conical part and a cylindrical part, but with channels for the passage of the drink having a variety of shapes, all designed to minimise the turbulence of the flow.
In particular, the compensator described in European patent EP 1 238 941 is equipped with at least two converging channels, which start from the corresponding inlets along the outer surface of the compensator and only converge on one another at the outlet area on the free end of the cylindrical body of the compensator, which said channels are designed to create two converging currents of the drink so that the two currents are partly mixed.
Said solution is designed to reduce the possibility of vortexes and turbulence in the drink output from the compensator.
The said arrangement of the channels reduces the turbulence of the flow, but when the compensator is in its forwardmost position in the direction of flow (ie. when it is positioned to maximise the flow, and the gate valve head is partly inserted into a cavity in the outlet area of the compensator channels to further reduce the turbulence of the flow), the edges of said head come too close to the edges of said cavity, with the result that the cross-sectional area through which the fluid flows is locally reduced. This generates a local increase in velocity that leads to a pressure reduction, and consequently the development of gas.
The present invention is designed to overcome the drawback described above, using a compensator device having an original channel shape, as claimed in claim 1, which maintains the turbulence within very narrow limits and prevents said sudden increases in velocity which cause the development of gas, and consequently froth.
The channels, which begin on the outer surface of the compensator, lead to a longitudinal channel coaxial with a wide, flattened cross-sectional area, so that when the gate valve head is partly inserted into a cavity in the outlet area of the compensator to reduce turbulence, there are always at least two passages through which the drink can flow, so as not to cause local flow accelerations and consequent gas formation.
A compensator in accordance with the present invention produces a flow virtually free of turbulence under all possible conditions of use, ie. whether large or small amounts are dispensed.
The invention will now be described according to a preferred embodiment, with reference to the annexed figures, wherein:

figure 1 shows a tap according to the invention, fitted to a dispensing line;
figure 2 shows the tap according to the invention in cross-section;
figure 3 shows the compensator device according to the invention;
figure 4 shows the flow passages in the area between the end of the compensator and the head of the gate valve.

As shown in fig. 1, (1) indicates a tap according to the invention, which is designed to be fitted to a dispensing line (2) of the type commonly used in public houses to dispense beer and carbonated drinks.
In fig. 2, tap (1) is shown according to a cross-section obtained with the vertical plane of symmetry. An inlet (3), through which the drink enters tap (1), and a pipe (4), into which a compensator device (5) according to the invention is inserted, can be seen in said cross-section.
Said pipe (4), which comprises a first cylindrical part connected to a second cone frustum-shaped part coaxial with the first part, leads into a chamber (6) that communicates with a spout (7) through which the drink is dispensed.
The passage from chamber (6) to spout (7) is controlled by a gate valve (8) driven by a lever (9). As gate valve device (8) is of known type, it will not be further described.
Compensator device (5) comprises a conical part (5a) and a cylindrical part (5b), illustrated in more detail in fig. 3. Conical part (5a) has a conicity substantially equal to that of the cone frustum-shaped part of pipe (4), so that when compensator (5) is fully inserted into pipe (4), the passage through which the drink flows is substantially closed. In practice, the two conical surfaces are not designed to effect a perfect seal, which is the task of gate valve (8), but the axial movement of compensator (5) serves to vary the cross-sectional area of the passage, and consequently to vary the flow rate of the drink dispensed.
The axial movement of compensator (5) is obtained with a cam device (10) of known type, driven by a lever (11), which engages with a pin (12) a seating (13) on one side of the cylindrical part of compensator (5), said cylindrical part (5b) having the function of guiding the axial movement of compensator (5).
Compensator (5) includes at least one pair of channels (14, 14a) which are converging and symmetrical in relation to axis (15) of compensator (5). The two channels (14, 14a) lead into an axial channel (16) which, in turn, exits from the cylindrical end (5b) of compensator (5). There is a recess (17) at said outlet.
The two channels (14, 14a) preferably have a circular cross-sectional area with a diameter d, and are inclined by an angle α in relation to the axis (15) of compensator (5).
The cross-sectional area of axial channel (16) has a length a and a width b. In practice, as shown in fig. 3, channel (16) can be made with a mill of diameter b which cuts a groove with depth c and length a. As shown in the detail illustrated in fig. 4, width b of the cross-sectional area of channel (16) must be as great as possible, compatibly with the need to avoid interference with seating (13) into which eccentric bolt (12) that controls the axial movements of compensator (5) is inserted. With the usual compensator dimensions, the ratio between a and b is between 2 and 3.
There is a circular recess of diameter D_i and depth c₁ on the end of cylindrical part (5a) of compensator (5).
According to a preferred form of embodiment, said diameter D_i is equal to length a of the cross-sectional area of channel (16).
Moreover, compensator (5) has a length H and an outer diameter D_e of 57 mm and 19 mm respectively; in other words, outer diameter D_e is a third of length H. Channels (14, 14a) have a diameter d of 6 mm and an inclination α of 30° in relation to axis (15) of compensator (5), although excellent results are also obtained with an angle of inclination α between 25° and 35°.
Longitudinal channel (16) has a cross-sectional area with a length a of 14 mm and a width b of 6 mm.
According to said preferred form of embodiment of the invention, recess (17) has a diameter D_i which coincides with length a of the cross-sectional area of channel (16), namely 14 mm. The depth c₁ of said recess (17) is 1,5 mm.
Fig. 4 shows tap (1) with compensator (5) in the fully retracted position. In this configuration, the flow rate of the drink dispensed is maximised, and head (8a) of gate valve (8) partly penetrates into recess (17) at the end of compensator (5).
Under these circumstances, the flow of drink which arrives from pipe (4), passes through the annular space between compensator (5) and said pipe (4), flows into channels (14, 14a) and reaches axial channel (16), and from there flows into recess (17), arrives at head (8a) of gate valve (8), which is partly inserted in recess (17) in said position.
The head of gate valve (8) forces the flow of the drink to deviate towards the walls of chamber (6) and flow around head (8a). This route is facilitated by the particular design of channel (16), which is flat and has a cross-sectional area with a length a greater than the diameter of head (8a) of gate valve (8), as shown in the detail illustrated in fig. 4. In practice, the ends of said channel (16) are not covered by head (8a) of gate valve (8), so that at least part of the drink flows directly, without encountering any obstacles that substantially divert its flow.
A facilitated route like the one described means less acceleration of the drink as it flows from channel (16) to chamber (6), less pressure reduction, and consequently less development of gas.
The above description clearly demonstrates that the compensator according to the invention solves the problem of limiting the reduction in flow pressure, even in the situation of maximum flow rate, thus effectively controlling froth formation under all circumstances.
The invention has been described by way of example but not of limitation, according to a preferred form of embodiment. One skilled in the art could devise other forms of embodiment, all of which fall into the ambit of protection of the following claims.

Claims

Tap of the type designed to dispense carbonated drinks, equipped with a compensator (5) designed to limit froth formation during dispensing, said compensator (5) having a cone frustum shape which is inserted into the flow of the drink dispensed in such a way that said drink flows through an annular channel, contained between the outer walls of said conical compensator (5) and a pipe (4) which contains said compensator (5), which said compensator (5) includes at least one pair of channels (14, 14a), that lead from the outer surface of said compensator (5) to an axial channel (16) in the body of said compensator (5), and which said compensator (5) includes a recess (17) into which head (8a) of a gate valve (8) is at least partly inserted, characterised in that said channel (16) has a cross-sectional shape such that the ends of said channel (16) are not covered by said head (8a) of said gate valve (8), the shape of said channel (16) being such that the cross-sectional area has a length a greater than the diameter of said head (8a) of said gate valve (8), so that at least part of the drink flows directly, without encountering any obstacles that substantially divert its flow.
Tap as claimed in claim 1, characterised in that said channel (16) has a cross-sectional area with a length a and width b such that the ratio between b and a is between 2 and 3.
Tap as claimed in claim 2, characterised in that said channel (16) has a cross-sectional area with a length a of 14 mm and a width b of 6 mm.
Tap as claimed in claim 1, characterised in that said recess (17) in said compensator (5) has a diameter D_i equal to the length a of said cross-sectional area of said channel (16).
Tap as claimed in claim 1, characterised in that said recess (17) in said compensator (5) has a depth c₁ of 1.5 mm.
Tap as claimed in claim 1, characterised in that said channels (14, 14a) are inclined by an angle α in relation to the axis (15) of said compensator (5).
Tap as claimed in claim 6, characterised in that said angle α of inclination of said channels (14, 14a) in relation to said axis (15) of said compensator (5) is between 25° and 35°.
Tap as claimed in claim 5, characterised in that said angle α of inclination of said channels (14, 14a) in relation to said axis (15) of said compensator (5) is 30°.
Tap as claimed in claim 1, characterised in that said channels (14, 14a) have a diameter of 6 mm.
Tap as claimed in at least one of claims 1 to 9, characterised in that the ratio between the outer diameter D_e and length H of said compensator (5) is one-third.