Title:
ROOT BEER POSTMIX DRINK DISPENSER
United States Patent 3584762
Abstract:
A carbonated postmix drink dispenser in which syrup under pressure is jetted through carbonated water under pressure to a zone of atmospheric pressure while the major portion of the carbonated water is segregated under pressure and aerated with minute air particles as it is expanded by CO2 ebullitions at atmospheric pressure prior to final mixing with the major portion of the syrup.
US Patent References:
Foam controlling beer faucet
Howard et al. - January 1936 - 2028283
Double stroke variable control fluid dispensing valve
Chudnow - January 1962 - 3015420
Combined liquid spray and aerator
Corlett et al. - November 1966 - 3286935
Swivel spray aerators
Moen - August 1967 - 3334818
Foam controlling beer faucet
Howard et al. - January 1936 - 2028283
Double stroke variable control fluid dispensing valve
Chudnow - January 1962 - 3015420
Combined liquid spray and aerator
Corlett et al. - November 1966 - 3286935
Swivel spray aerators
Moen - August 1967 - 3334818
Inventors:
Vantroba, Robert W. (Wauconda, IL)
Allen, Donald L. (Skokie, IL)
Allen, Donald L. (Skokie, IL)
Application Number:
04/781008
Publication Date:
06/15/1971
Filing Date:
12/04/1968
View Patent Images:
Export Citation:
Assignee:
The Golconda Corporation (Chicago, IL)
Primary Class:
Other Classes:
137/170.400, 222/129.100, 239/428.500
International Classes:
B67D1/00; B67D5/56
Field of Search:
239/427.5,428,428.5,432,433,434.5 222/129.1,129.3,145,190,1 137/170.1,170.2,170.4,170.5 99/79
Primary Examiner:
Reeves, Robert B.
Assistant Examiner:
Lane H. S.
Claims:
What we claim is
1. A root beer dispenser comprising a draft head including a dispensing nozzle and defining two passageways separately conducting root beer syrup and carbonated water under pressure to said nozzle,
2. The dispenser defined in claim 1 in which said said dispensing nozzle is enlarged radially below said pressure reducing means to define a shoulder where the carbonated water leaves the pressure-reducing area, and
3. A carbonated drink dispenser comprising a draft head including a dispensing nozzle and defining two passageways separately conducting syrup and carbonated water under pressure to said nozzle,
4. The drink dispenser defined in claim 3 in which said pressure-reducing means forms with the internal wall of the dispensing nozzle a space having diverging walls at the outlet of said conduits, and
5. The drink dispenser defined in claim 3 in which the wall of said dispensing nozzle includes a wall section of reduced diameter defining an upper shoulder,
6. The drink dispenser defined in claim 5 in which said wall section of reduced diameter defines a lower shoulder and forms a part of a discharge passage having diverging walls connected to said conduits, and
7. In a carbonated drink dispenser, a dispensing nozzle for aerating a potable carbonated liquid received by it under pressure,
8. The nozzle defined in claim 7 in which the wall of the nozzle includes a section of reduced diameter defining an upwardly facing shoulder, supporting said wall portion of said wafer, and
9. The nozzle defined in claim 7 in which the wall of the nozzle includes a section of reduced diameter defining a downwardly facing shoulder defining in part said enlarged flow area space,
10. The nozzle defined claim 7 in which the head portion of said pressure-reducing wafer is supported on said wall portion by a neck portion providing space between them, and
11. The nozzle defined in claim 10 including a nozzle concentric with said control passage for hydraulically driving some carbonated liquid through said central passage by a flavoring liquid that is ejected from said concentric nozzle under pressure.
12. The process of dispensing a post mix beverage of syrup and carbonated water into a glass to provide a foam head of long duration thereon comprising:
13. The process defined in claim 12 including the step of mixing the syrup and carbonated water by gravity flow along an inclined wall for minimum turbulence.
14. The process of postmix dispensing a beverage of syrup and carbonated water in a glass to provide a foam head having gas particles of minuteness equivalent to premixed syrup and carbonated water comprising:
15. The process defined in claim 14 in which the last mentioned step includes jetting the syrup through the high-pressure space through carbonated water and into intimate mixture with the aerated water at said low pressure.
16. The process defined in claim 14 including confining the flow of the carbonated water in the low-pressure space to collect and expand rapidly released CO2 gas as minute bubbles in the liquid phase of the carbonated water and
1. A root beer dispenser comprising a draft head including a dispensing nozzle and defining two passageways separately conducting root beer syrup and carbonated water under pressure to said nozzle,
2. The dispenser defined in claim 1 in which said said dispensing nozzle is enlarged radially below said pressure reducing means to define a shoulder where the carbonated water leaves the pressure-reducing area, and
3. A carbonated drink dispenser comprising a draft head including a dispensing nozzle and defining two passageways separately conducting syrup and carbonated water under pressure to said nozzle,
4. The drink dispenser defined in claim 3 in which said pressure-reducing means forms with the internal wall of the dispensing nozzle a space having diverging walls at the outlet of said conduits, and
5. The drink dispenser defined in claim 3 in which the wall of said dispensing nozzle includes a wall section of reduced diameter defining an upper shoulder,
6. The drink dispenser defined in claim 5 in which said wall section of reduced diameter defines a lower shoulder and forms a part of a discharge passage having diverging walls connected to said conduits, and
7. In a carbonated drink dispenser, a dispensing nozzle for aerating a potable carbonated liquid received by it under pressure,
8. The nozzle defined in claim 7 in which the wall of the nozzle includes a section of reduced diameter defining an upwardly facing shoulder, supporting said wall portion of said wafer, and
9. The nozzle defined in claim 7 in which the wall of the nozzle includes a section of reduced diameter defining a downwardly facing shoulder defining in part said enlarged flow area space,
10. The nozzle defined claim 7 in which the head portion of said pressure-reducing wafer is supported on said wall portion by a neck portion providing space between them, and
11. The nozzle defined in claim 10 including a nozzle concentric with said control passage for hydraulically driving some carbonated liquid through said central passage by a flavoring liquid that is ejected from said concentric nozzle under pressure.
12. The process of dispensing a post mix beverage of syrup and carbonated water into a glass to provide a foam head of long duration thereon comprising:
13. The process defined in claim 12 including the step of mixing the syrup and carbonated water by gravity flow along an inclined wall for minimum turbulence.
14. The process of postmix dispensing a beverage of syrup and carbonated water in a glass to provide a foam head having gas particles of minuteness equivalent to premixed syrup and carbonated water comprising:
15. The process defined in claim 14 in which the last mentioned step includes jetting the syrup through the high-pressure space through carbonated water and into intimate mixture with the aerated water at said low pressure.
16. The process defined in claim 14 including confining the flow of the carbonated water in the low-pressure space to collect and expand rapidly released CO2 gas as minute bubbles in the liquid phase of the carbonated water and
Description:
BACKGROUND OF THE INVENTION
Heretofore premix root beer, drafted from a vat, has established a visual public acceptance standard of a foam "head" which is difficult to reproduce by a postmix dispensing root beer, i.e., mixed when dispensed, which is more desirable for health and sanitation reasons. An enduring foam head of less than one-fourth of the height of the drink is looked for. More head then that is deemed to be "skimping" on the beverage notwithstanding the increase of cost to supply additional CO 2 that is substantially lost in an unsuccessful endeavor to increase head duration. Less then 15 percent on postmix root beer has not been enduring nor considered by the public to be adequately carbonated.
Foaming agents have been employed to hold the head by they objectionably change the taste. Root beer cold enough to provide some duration of ebullition is too cold and generally considered to be too sharp in its taste for the first few swallows and too flat for the last few swallows. Correct temperature and carbonation can be provided for taste by the foam head substantially disappears within a minute. Mechanical endeavors to make a higher head by pouring the mix against the bottom of the glass only make the head less enduring and flattens the taste. Pouring against the side of the glass provides a smaller head that is a little more enduring but with a metering dispenser does not fill the glass adequately.
SUMMARY OF THE INVENTION
We have discovered that if the loss of CO 2 by ebullition and rapid expansion at the time of postmix reduction of pressure upon the carbonated water is relied upon and utilized to provide the carbonated water with a fine porosity the CO 2 is not entirely lost and can be combined with or substantially replaced by fine particles of air, with the result that the desired carbonation is retained substantially the same as in premix draft root beer and the duration of the foam head is generally longer than that for premix dispensing. The fine particles of air are entrained by a surface tension that is not subject to ebullition as the carbonated beverage warms towards room temperature during the time the serving is being intermittently tippled. The air remains entrained to preserve the head as long as nine minutes and also tends to retard the escape of CO 2 gas in the foam enough that continuing ebullition of CO 2 and the carbonated liquid maintains a visual head that is satisfactory. Moreover, the size of this head can be adjusted to be initially greater or less than the premix head for approximately the same duration for different communities Also the ultimate amount of CO 2 contained in the drink for taste acceptance in various communities can be varied without substantially changing the height of the foam head.
The beverage syrup is propelled from an orifice with approximately 10 p.s.i. pressure, for a brief distance through a chamber filled with carbonated water under pressure and out through an opening into another compartment at atmospheric pressure. Carbonated water is simultaneously discharged into and from the chamber under pressure. A minor portion is carried with the syrup by the major portion thereof is discharged through a plurality of pressure-dropping conduits and past air-syphoning openings to aerate the carbonated water at the time the pressure thereon is reduced to atmospheric pressure. The aerated water flows along with the syrup into a glass where final mixing occurs preferably with minimum turbulence. For the prolongation of aerated foam the aerating effect can be varied by simple adjustment. The proportion of syrup to carbonated water can also be adjusted by applied pressure upon the syrup and the amount of resulting foam can be controlled by the operator as it leaves the nozzle by varying the angle of the sidewall of the glass contacted in drafting the same as is done with premix dispensing.
A primary object is to provide substantially identical taste and look in a beverage whether dispensed as a premix or a postmix product; another object is to provide a root beer beverage with which different characteristics thereof can be varied according to different communities. A further primary object is to provide a premix-type beverage whose ingredients are handled under complete health and sanitation conditions even over long periods of storage between dispensings; and the equipment can be quickly and completely cleaned in brief periods of time.
Other and further objects including apparatus, simplicity and ease of manufacturing and servicing will become apparent from the drawings, and the description of the embodiments illustrated therein.
In the drawings:
FIG. 1 is a side elevational view of a beverage-dispensing head, partly in section, embodying the invention;
FIG. 2 is an enlarged longitudinal sectional view of a nozzle embodying the invention;
FIG. 3 is a cross-sectional view taken on line 3-3 in FIG. 2;
FIG. 4 is a longitudinal sectional view of the lower portion of a beverage dispensing nozzle embodying a modification;
FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 4;
FIG. 6 is a longitudinal sectional view similar to FIG. 4 showing another embodiment of the invention;
FIGS. 7 and 8 are cross-sectional views taken in opposite directions as indicated by the arrows 7-7 and 8-8.
FIG. 9 is a perspective view of the pressure reducing wafer shown in FIGS. 6 to 8; and
FIG. 10 is a graph relating foam head duration along the ordinate with respect to the relative axial position of the pressure reducer wafer as the abscissa.
Referring now to the drawings in further detail, reference and incorporation of the disclosure of YUZA U.S. Pat. No 3,373,937 is hereby expressly made for the operation of the construction shown in FIG. 1 herein up to the point that syrup is conveyed to the syrup nozzle 10 under pressure and carbonated water reaches the interior of the dispensing nozzle 12 under pressure. It is sufficient here to indicate that an above-counter drink-dispensing head 14 is supported on a draft arm upright 16 through which carbonated water at approximately 100 p.s.i. pressure at 40° F. and syrup at approximately 10 p.s.i. pressure are supplied separately to solenoid valves (not shown) that are controlled simultaneously by a switch arm 18 when a glass is pressed against it below the dispensing nozzle 12. From the valves the carbonated water flows through passage 20 to a flow-controlling device 22, then outwardly and downwardly over the inner wall 24 of the nozzle 26. The syrup is conveyed through the passage 28 as adjustably controlled by a needle valve 27 to the syrup nozzle 10 for axial discharge downwardly through an orifice 30, which is about 0.093 of an inch in diameter and about one-half inch long. Preferably the nozzle 26 is transparent and is threadably mounted at 32 for removal and cleaning, and the nozzle 10 is threadably mounted at 34 to remove for cleaning also when nozzle 26 is removed.
As more particularly shown in FIG. 2, the inner wall 24 is conical and converges downwardly to a surface of revolution having an upper portion 36 of a diameter approximately 0.717 of an inch, an intermediate portion 38 of a diameter approximately 0.600 and a lower portion 40 of a diameter of approximately 0.687 of an inch. The intermediate diameter portion provides an upper shoulder 42 and a lower shoulder 44. Openings from the atmosphere outside of the nozzle to the lower portion 40 are provided immediately below the lower shoulder and in FIGS. 1 and 2 comprise radially directed slots 46 about 0.047 of an inch wide in a vertical direction. In this embodiment there are three slots which can be made by circular saw cuts with a metal-cutting saw approximately 1 inch in diameter.
A pressure reducing wafer 48 rests upon the upper shoulder 42 and is provided with 12 equally spaced holes 50 that are 0.040 of an inch in diameter Below the wafer and within the intermediate portion 38 is a head member 52 having a diameter of approximately 0.531 of an inch and a height of about 0.156 of an inch with a supporting neck 54 that is 0.281 of an inch in diameter. These dimensions provide a space 56 of 0.031 of an inch below the openings 50 connected to a flow passage of 0.0625 of an inch at 58 between the periphery of the head and the wall portion 38. The corners 61 of the head are rounded to a one-sixteenth of an inch radius and the lower face 60 of the head is approximately coplanar with the bottom surface 63 of the slots 46 at a location which for purposes of describing FIG. 10 may be referred to as the No. 1 station. A central opening 62 approximately 0.100 of an inch in diameter, extends through the pressure-reducing wafer 48, and it will be noted from FIG. 4 that the pressure-reducing wafer 48 can be made either as an integral member or as an assembly of two elements threaded together as at 64 where further adjustment can be provided if desired.
In FIGS. 6 to 9 a pressure reducer wafer 48A is provided which is bodily adjustable as to relative height location with the aeration openings 46. In providing this the shoulder 42A is provided with cam ramps 70 which engage cooperating cam elements 72 on the lower marginal edges of the wafer 48. Adjustable rotation of the wafer to activate the cam means is accomplished by the hole 62A being provided with a hexagonal shape to receive an Allen wrench. Furthermore, to provide an adjustable securement of position, the wafer is made slightly oversize and is radially split at 74 to yield inwardly and frictionally engage the walls of the portion 36 to hold any adjusted position and height on the cams 72.
Referring again to FIGS. 4 and 5, downwardly converging drill passages 76 can be used in place of the saw cut slots 46 to open into and below the lower shoulder 44 for aeration of carbonated liquid passing said shoulder. There are 24 passages 76, each approximately 0.040 of an inch in diameter and are drilled from the inside outwardly at approximately 45°. The shoulder 44 provides an excellent "starting" contour for the drill points in the drilling operation. This places the outlets of the passages 76 at the proper position in relation to the annular flow passage 58.
In operation FIG. 10 is referred to in which the curve indicates that aeration is an important factor when the carbonated water begins to disassociate and releases CO 2 at the major reduction of pressure to atmospheric pressure. Time of foam head duration is shown in seconds as the ordinate while the station location of the pressure reducer wafer with respect to the slots 46 is represented along the abscissa. Station 1 is shown in FIG. 2 and each successive station, 2, 3 and 4 is one thirty-second of an inch higher, established either by washers (not shown) placed between the shoulder 42 and the bottom of the wafer 48A or rotation of the wafer 48A to activate the cams 70 and 72 to provide the increments of measurement indicated.
Thus, it is to be observed that the greatest duration of approximately 9 minutes occurs with the lower face 60 one thirty-second of an inch above the bottom surface 63 of the slots 46 or one-sixteenth of an inch below the shoulder 44 where the beginning of the rounded lower marginal corner 61 of the head disposed colevel with the lower shoulder 44. This relates the essentially critical location in which the parallelism of the intermediate wall 38 and the circular wall of the head terminates at the same level below which pressure reduction occurs in a widened space into which air is aspirated as the pressure upon the carbonated water is reduced to atmospheric pressure.
Although in some respects we are not able to account fully for the improved results which are obtained by the method and apparatus of this invention, and although it should be understood that any attempt to analyze the theory which is believed to be responsible for these results is to be construed not as defining a mode of operation but merely as a possible explanation of certain physical phenomena which have been observed. The operation appears to be one in which the presence of air in the region where initial ebullition of CO 2 , due to reduction of pressure, provides the greatest entrainment of small particles of air which endure for a long period of time. Upstream of this point, the moving column of carbonated water is quite solid and downstream of this point the water particles otherwise can reunite after the expansion and release of CO 2 due to the ebullition during which minute air particles were not entrained.
It is well known that aeration of water at a water faucet is not very enduring in a glass nor is aeration significant with water passing through a venturi with an air inlet at the throat, but in the present invention minute air particles are entrained to provide enduring foam. Furthermore, with the further gradual ebullition of CO 2 after final mixture in the glass, the entrainment of the air particles in the carbonated water persists in the presence of the syrup mixture along with the liberated CO 2 that remains in the foam head.
In operation, syrup under a pressure of 5 to 15 p.s.i. is directed from the nozzle 10 through the opening 62 and as it passes through the carbonated water in the space defined by the upper wall portion 36, it marginally entrains some of the carbonated water and carries it through the opening 62.
While this is occurring the large portion of the carbonated water is being aerated with fine particles of air in that fine particles of air find space for entrainment by the ebullition of CO 2 and its expansion with turbulence breaking up the solidarity of the water. This portion of the mixture tends to shield the central stream of syrup and carbonated water and mixes therewith as it moves into the glass. Mixture of the two liquids is not finally accomplished until in the glass where the syrup tends to augment ebullition providing foam.
The question of duration is directly related to surface tension at the interfaces of the gas bubbles and the liquid. The smaller the bubbles or particles of gas are, the greater is the surface tension that lengthens the duration of the foam head on the beverage. The unusual minuteness of the gas bubbles in a mixture of carbonated water and syrup is established at the point of pressure reduction on the carbonated water where both release and rapid expansion of CO 2 along with turbulence of the air and water developed thereby comminute or establish unusually small particles of entrained air and a high surface tension factor for long duration of a satisfactory head on a glass of root beer beverage.
Throughout the specification and drawings, various dimensions and pressures have been indicated for purposes of illustration. These may be varied, especially if compensatory changes are made in other elements within the inventive concept set forth, and, having described several embodiments of the invention and suggested the manner in which they are believed to function and operate, it will be apparent to those skilled in the art that various uses, modifications, and changes may be made therein without departing from the spirit and substance of the invention.
Heretofore premix root beer, drafted from a vat, has established a visual public acceptance standard of a foam "head" which is difficult to reproduce by a postmix dispensing root beer, i.e., mixed when dispensed, which is more desirable for health and sanitation reasons. An enduring foam head of less than one-fourth of the height of the drink is looked for. More head then that is deemed to be "skimping" on the beverage notwithstanding the increase of cost to supply additional CO 2 that is substantially lost in an unsuccessful endeavor to increase head duration. Less then 15 percent on postmix root beer has not been enduring nor considered by the public to be adequately carbonated.
Foaming agents have been employed to hold the head by they objectionably change the taste. Root beer cold enough to provide some duration of ebullition is too cold and generally considered to be too sharp in its taste for the first few swallows and too flat for the last few swallows. Correct temperature and carbonation can be provided for taste by the foam head substantially disappears within a minute. Mechanical endeavors to make a higher head by pouring the mix against the bottom of the glass only make the head less enduring and flattens the taste. Pouring against the side of the glass provides a smaller head that is a little more enduring but with a metering dispenser does not fill the glass adequately.
SUMMARY OF THE INVENTION
We have discovered that if the loss of CO 2 by ebullition and rapid expansion at the time of postmix reduction of pressure upon the carbonated water is relied upon and utilized to provide the carbonated water with a fine porosity the CO 2 is not entirely lost and can be combined with or substantially replaced by fine particles of air, with the result that the desired carbonation is retained substantially the same as in premix draft root beer and the duration of the foam head is generally longer than that for premix dispensing. The fine particles of air are entrained by a surface tension that is not subject to ebullition as the carbonated beverage warms towards room temperature during the time the serving is being intermittently tippled. The air remains entrained to preserve the head as long as nine minutes and also tends to retard the escape of CO 2 gas in the foam enough that continuing ebullition of CO 2 and the carbonated liquid maintains a visual head that is satisfactory. Moreover, the size of this head can be adjusted to be initially greater or less than the premix head for approximately the same duration for different communities Also the ultimate amount of CO 2 contained in the drink for taste acceptance in various communities can be varied without substantially changing the height of the foam head.
The beverage syrup is propelled from an orifice with approximately 10 p.s.i. pressure, for a brief distance through a chamber filled with carbonated water under pressure and out through an opening into another compartment at atmospheric pressure. Carbonated water is simultaneously discharged into and from the chamber under pressure. A minor portion is carried with the syrup by the major portion thereof is discharged through a plurality of pressure-dropping conduits and past air-syphoning openings to aerate the carbonated water at the time the pressure thereon is reduced to atmospheric pressure. The aerated water flows along with the syrup into a glass where final mixing occurs preferably with minimum turbulence. For the prolongation of aerated foam the aerating effect can be varied by simple adjustment. The proportion of syrup to carbonated water can also be adjusted by applied pressure upon the syrup and the amount of resulting foam can be controlled by the operator as it leaves the nozzle by varying the angle of the sidewall of the glass contacted in drafting the same as is done with premix dispensing.
A primary object is to provide substantially identical taste and look in a beverage whether dispensed as a premix or a postmix product; another object is to provide a root beer beverage with which different characteristics thereof can be varied according to different communities. A further primary object is to provide a premix-type beverage whose ingredients are handled under complete health and sanitation conditions even over long periods of storage between dispensings; and the equipment can be quickly and completely cleaned in brief periods of time.
Other and further objects including apparatus, simplicity and ease of manufacturing and servicing will become apparent from the drawings, and the description of the embodiments illustrated therein.
In the drawings:
FIG. 1 is a side elevational view of a beverage-dispensing head, partly in section, embodying the invention;
FIG. 2 is an enlarged longitudinal sectional view of a nozzle embodying the invention;
FIG. 3 is a cross-sectional view taken on line 3-3 in FIG. 2;
FIG. 4 is a longitudinal sectional view of the lower portion of a beverage dispensing nozzle embodying a modification;
FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 4;
FIG. 6 is a longitudinal sectional view similar to FIG. 4 showing another embodiment of the invention;
FIGS. 7 and 8 are cross-sectional views taken in opposite directions as indicated by the arrows 7-7 and 8-8.
FIG. 9 is a perspective view of the pressure reducing wafer shown in FIGS. 6 to 8; and
FIG. 10 is a graph relating foam head duration along the ordinate with respect to the relative axial position of the pressure reducer wafer as the abscissa.
Referring now to the drawings in further detail, reference and incorporation of the disclosure of YUZA U.S. Pat. No 3,373,937 is hereby expressly made for the operation of the construction shown in FIG. 1 herein up to the point that syrup is conveyed to the syrup nozzle 10 under pressure and carbonated water reaches the interior of the dispensing nozzle 12 under pressure. It is sufficient here to indicate that an above-counter drink-dispensing head 14 is supported on a draft arm upright 16 through which carbonated water at approximately 100 p.s.i. pressure at 40° F. and syrup at approximately 10 p.s.i. pressure are supplied separately to solenoid valves (not shown) that are controlled simultaneously by a switch arm 18 when a glass is pressed against it below the dispensing nozzle 12. From the valves the carbonated water flows through passage 20 to a flow-controlling device 22, then outwardly and downwardly over the inner wall 24 of the nozzle 26. The syrup is conveyed through the passage 28 as adjustably controlled by a needle valve 27 to the syrup nozzle 10 for axial discharge downwardly through an orifice 30, which is about 0.093 of an inch in diameter and about one-half inch long. Preferably the nozzle 26 is transparent and is threadably mounted at 32 for removal and cleaning, and the nozzle 10 is threadably mounted at 34 to remove for cleaning also when nozzle 26 is removed.
As more particularly shown in FIG. 2, the inner wall 24 is conical and converges downwardly to a surface of revolution having an upper portion 36 of a diameter approximately 0.717 of an inch, an intermediate portion 38 of a diameter approximately 0.600 and a lower portion 40 of a diameter of approximately 0.687 of an inch. The intermediate diameter portion provides an upper shoulder 42 and a lower shoulder 44. Openings from the atmosphere outside of the nozzle to the lower portion 40 are provided immediately below the lower shoulder and in FIGS. 1 and 2 comprise radially directed slots 46 about 0.047 of an inch wide in a vertical direction. In this embodiment there are three slots which can be made by circular saw cuts with a metal-cutting saw approximately 1 inch in diameter.
A pressure reducing wafer 48 rests upon the upper shoulder 42 and is provided with 12 equally spaced holes 50 that are 0.040 of an inch in diameter Below the wafer and within the intermediate portion 38 is a head member 52 having a diameter of approximately 0.531 of an inch and a height of about 0.156 of an inch with a supporting neck 54 that is 0.281 of an inch in diameter. These dimensions provide a space 56 of 0.031 of an inch below the openings 50 connected to a flow passage of 0.0625 of an inch at 58 between the periphery of the head and the wall portion 38. The corners 61 of the head are rounded to a one-sixteenth of an inch radius and the lower face 60 of the head is approximately coplanar with the bottom surface 63 of the slots 46 at a location which for purposes of describing FIG. 10 may be referred to as the No. 1 station. A central opening 62 approximately 0.100 of an inch in diameter, extends through the pressure-reducing wafer 48, and it will be noted from FIG. 4 that the pressure-reducing wafer 48 can be made either as an integral member or as an assembly of two elements threaded together as at 64 where further adjustment can be provided if desired.
In FIGS. 6 to 9 a pressure reducer wafer 48A is provided which is bodily adjustable as to relative height location with the aeration openings 46. In providing this the shoulder 42A is provided with cam ramps 70 which engage cooperating cam elements 72 on the lower marginal edges of the wafer 48. Adjustable rotation of the wafer to activate the cam means is accomplished by the hole 62A being provided with a hexagonal shape to receive an Allen wrench. Furthermore, to provide an adjustable securement of position, the wafer is made slightly oversize and is radially split at 74 to yield inwardly and frictionally engage the walls of the portion 36 to hold any adjusted position and height on the cams 72.
Referring again to FIGS. 4 and 5, downwardly converging drill passages 76 can be used in place of the saw cut slots 46 to open into and below the lower shoulder 44 for aeration of carbonated liquid passing said shoulder. There are 24 passages 76, each approximately 0.040 of an inch in diameter and are drilled from the inside outwardly at approximately 45°. The shoulder 44 provides an excellent "starting" contour for the drill points in the drilling operation. This places the outlets of the passages 76 at the proper position in relation to the annular flow passage 58.
In operation FIG. 10 is referred to in which the curve indicates that aeration is an important factor when the carbonated water begins to disassociate and releases CO 2 at the major reduction of pressure to atmospheric pressure. Time of foam head duration is shown in seconds as the ordinate while the station location of the pressure reducer wafer with respect to the slots 46 is represented along the abscissa. Station 1 is shown in FIG. 2 and each successive station, 2, 3 and 4 is one thirty-second of an inch higher, established either by washers (not shown) placed between the shoulder 42 and the bottom of the wafer 48A or rotation of the wafer 48A to activate the cams 70 and 72 to provide the increments of measurement indicated.
Thus, it is to be observed that the greatest duration of approximately 9 minutes occurs with the lower face 60 one thirty-second of an inch above the bottom surface 63 of the slots 46 or one-sixteenth of an inch below the shoulder 44 where the beginning of the rounded lower marginal corner 61 of the head disposed colevel with the lower shoulder 44. This relates the essentially critical location in which the parallelism of the intermediate wall 38 and the circular wall of the head terminates at the same level below which pressure reduction occurs in a widened space into which air is aspirated as the pressure upon the carbonated water is reduced to atmospheric pressure.
Although in some respects we are not able to account fully for the improved results which are obtained by the method and apparatus of this invention, and although it should be understood that any attempt to analyze the theory which is believed to be responsible for these results is to be construed not as defining a mode of operation but merely as a possible explanation of certain physical phenomena which have been observed. The operation appears to be one in which the presence of air in the region where initial ebullition of CO 2 , due to reduction of pressure, provides the greatest entrainment of small particles of air which endure for a long period of time. Upstream of this point, the moving column of carbonated water is quite solid and downstream of this point the water particles otherwise can reunite after the expansion and release of CO 2 due to the ebullition during which minute air particles were not entrained.
It is well known that aeration of water at a water faucet is not very enduring in a glass nor is aeration significant with water passing through a venturi with an air inlet at the throat, but in the present invention minute air particles are entrained to provide enduring foam. Furthermore, with the further gradual ebullition of CO 2 after final mixture in the glass, the entrainment of the air particles in the carbonated water persists in the presence of the syrup mixture along with the liberated CO 2 that remains in the foam head.
In operation, syrup under a pressure of 5 to 15 p.s.i. is directed from the nozzle 10 through the opening 62 and as it passes through the carbonated water in the space defined by the upper wall portion 36, it marginally entrains some of the carbonated water and carries it through the opening 62.
While this is occurring the large portion of the carbonated water is being aerated with fine particles of air in that fine particles of air find space for entrainment by the ebullition of CO 2 and its expansion with turbulence breaking up the solidarity of the water. This portion of the mixture tends to shield the central stream of syrup and carbonated water and mixes therewith as it moves into the glass. Mixture of the two liquids is not finally accomplished until in the glass where the syrup tends to augment ebullition providing foam.
The question of duration is directly related to surface tension at the interfaces of the gas bubbles and the liquid. The smaller the bubbles or particles of gas are, the greater is the surface tension that lengthens the duration of the foam head on the beverage. The unusual minuteness of the gas bubbles in a mixture of carbonated water and syrup is established at the point of pressure reduction on the carbonated water where both release and rapid expansion of CO 2 along with turbulence of the air and water developed thereby comminute or establish unusually small particles of entrained air and a high surface tension factor for long duration of a satisfactory head on a glass of root beer beverage.
Throughout the specification and drawings, various dimensions and pressures have been indicated for purposes of illustration. These may be varied, especially if compensatory changes are made in other elements within the inventive concept set forth, and, having described several embodiments of the invention and suggested the manner in which they are believed to function and operate, it will be apparent to those skilled in the art that various uses, modifications, and changes may be made therein without departing from the spirit and substance of the invention.