US 3583446 A
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United States Patent  Inventor FrankE.Rush,Jr.
Newark, Del.  Appl. No 739,286 122] Filed June 24, 1968  Patented June 8, 1971  PROCESS AND APPARATUS FOR LOADING 2,156,834 5/1939 Berry 141/105X 3,868,584 l/1959 Faust l37/604X 2,908,227 10/1959 McDougall v 137/604X 3,042,071 7/1962 Van Tuyl l l. l3 /604X 3,132,774 5/1964 Soffer o ZZZ/402.22 3,167,091 1/1965 Holdren 137/604 Primary Examiner-Herbert F. Ross AtrorneyFrancis J, Crowley ABSTRACT: In the process of loading pressurized dispensing containers with a fluid product and a normally gaseous propellant or combination of propellants, the improvement consisting in causing pipeline streams of said fluid product and said propellant or combination of propellants to mix under critical conditions in a tee of critical design thus premixing the components before they enter said container; and apparatus for carrying out the premixing.
PATENIEIJ JUN a I97I 3583,2145
sum 1 UF 2 FIG- 2.
VALVE IN OPEN POSITION PATENTEU JUN 8 IHYI 3; 583446 sum 2 OF 2 +-VALVE OPEN E2 5 PO ION PROCESS AND APPARATUS FOR LOADING CONTAINERS BACKGROUND The usual commercial practice of loading pressurized dispensing containers with fluid or semifluid products consists in filling a usually evacuated container at least about half full with the fluid product and then pressurizing the propellant or mixture of propellants into the partially filled container. When the container is filled through an open end and is subsequently closed by crimping the top in place, the process is called under-the-cap filling. Alternatively, the assembled container, usually evacuated, is sometimes charged in part or entirely through the valve. The large volume loader generally prefers the under-the-cap process carried out in large automatic machines. The small volume loader often prefers through-thevalve loading because of the lesser investment in machinery.
A number of propellants either alone (except as noted) or in combination are in current use: dichlorodifluoromethane, dichlorofluoromethane, l,2-dichlorotetrafluoroethane, octafluorocyclobutane, chloropentafluoroethane, trichlorofluoromethane, chlorodifluoromethane, l, ldifluoroethane, vinyl chloride, nitrous oxide (in mixture with liquefiable propellants), carbon dioxide, nitrogen (in mixture with liquefiable propellants), and low boiling normally gaseous hydrocarbons such as isobutane or propane.
For use in dispensing products intended for human consumption, the U.S. Food and Drug Administration allows octafluorocyclobutane, chloropentafluoroethane, nitrous oxide, nitrogen, propane, and carbon dioxide to be used as propellants.
Propellants or mixtures of propellants which are condensable at ambient temperature at a pressure less than the bursting pressure of the container can be conveniently loaded in the liquid phase without danger of bursting the container. Commonly used propellantssuch as carbon dioxide and nitrous oxide, however, have vapor pressures much higher than the bursting pressures of the usual commercial dispensing containers. As a rule, gases which do not condense at pressures below the allowable pressure for the container cannot be charged in sufficient quantity to expel the contents unless they are at least slightly soluble in the fluid or semifluid product. Noncondensing gases, even though soluble in the fluid product, cause difficulties in loading because of the slow rate at which they dissolve. In practice it has been found necessary to shake the container while it is being charged with soluble high vapor pressure gases either alone or (frequently) in mixture with condensable gas propellants. The high initial pressure which prevails before the soluble propellant has'dissolved sometimes ruptures the container.
ln loading products which foam on expulsion, such as diary cream, dessert toppings, purees and shaving soap, the containers must be shaken for up to a minute regardless of the propellants used in order to insure foaming on expulsion.
The contents of containers filled nearly full often cannot be mixed even by prolonged shaking.
Because of high initial pressure and/or inability to mix by shaking, containers for some products, for example, dairy cream, are filled only about half full.
Of all the steps of loading, the step of shaking takes the most time. Some commercial loaders have installed multiple shakers to serve a single loading line.
There was, therefore, a need and it is an object of this invention to provide a device and a process for the loading of pressurized dispensing containers with a fluid or semifluid product and a propellant or propellant mixture without shaking the container. It is a further object to provide a means for filling pressurized dispensing containers nearly full.
SUMMARY OF THE INVENTION These and other objectives are accomplished according to the subject invention by, in a process for loading pressurized dispensing containers through the valve with fluid products and normally gaseous propellants, premixing streams of such fluid products and propellants under turbulent conditions in close proximity to said container and while en route to loading for a time sufficient to achieve substantially complete mixing.
The novel T-mixer apparatus of this invention has a substantially straight conduit or passageway in its housing for conveying the fluid product to the container; and, preferably at right angles and connecting thereto, a side inlet or conduit to feed the propellant(s) into the passageway.
Dimensions, stream velocities, pressure drops, etc., are critical dependent variables as hereinafter discussed.
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an overall plan view of one embodiment of the T- mixer apparatus complete withpiping arrangement;
FIG. 2 is a cross-sectional view of the T-mixer embodiment of FIG. I in operable engagement with a dispensing container valve; and
FIG. 3 is a cross-sectional view of another embodiment of the T-mixer apparatus in operable engagement with a dispensing container valve.
DETAILED DESCRIPTION OF INVENTION Drawings Referring in more detail to the two embodiments shown by way of example in the accompanying drawings;
FIGS. 1 and 2 show one embodiment of the T-mixe'r generally comprising'T mixer housing 10, together with a typical pipingarrangement 12, fluid product conduit or passageway 14 and propellant side inlet conduit 16. The upstream end" of housing 10 is internally threaded (at 18) to receive a suitable piping arrangement I2. The enlarged portion of side inlet conduit [6 is'alsothreadediat 20) for connection to suitable propellant supply means (not shown). D,, D, and D 'refer, respectively, to the inner diameters of the upstream portionof conduit 14, the downstream portion of conduit l4 and the side inletconduit' 16. Housing 10 has'a recess 22 at the downstream end adapted to slidably receive the tip of the dispensing container valve 24. The shape of the recess (-here'cylindrically shaped) is-determiried by the configuration of the container valve. The valve shown in FIGS. 2 and 3 is a conventional Clayton valve (see U.S. Pat. No. 3,l32,774 for further discussidn'of Clayton valves). Recess 22 is provided with O-ring 26 to slidably engagevalve 24 to ensure an airtight seal when in operation. In this embodiment housing 10 has a cylindrical, elongated portion 28 concentric within and extending beyond recess 22so' that the downstream portion of passageway l4will fit within and extend down into'valve tube 24 when'in loading position.
Theernbo'dirnentof FIG. 3 is identical tothat of FIG. 2except'that housingl'llis not provided with an'elongated portion (28) as in FIG. 2. Instead, the dispenser valve 24 itself serves as thedownstreamor tailpipe section of the passageway 14. An additional Okingse'al 30'is provided in this embodiment at the upper end of recess-2210 assure an airtight closure.
It is to beunderstood that this invention may be adapted to be used with various types of valves, though Clayton-type valves-arepreferred for foamy products. This invention may also be adapted foruse in under-'the-cap filling of dispensers.
In both embodiments, conduits l4 and 16 are each preferably cylindrical, i.e., have circular cross sections. However, other cross-sectional shapes (e.g. elliptical) could obviously be employed if desired.
Determination of Apparatus and Process Variables It is found that propellants or mixtures of propellants, preferably liquefied, can be mixed with'fluid or semifluid products [liquefied normally gaseous fluids are'also operable] in a T-mixer of critical dimensions and under critical conditions while the components are en route to a pressurized dispensing container, thus making it unnecessary to shake said container during filling and permitting the filling of containers nearly full. The propellants listed above are typical propellants operable with this invention.
Operable fluid products include all fluid or semifluid products which can be expelled from a pressurized dispensing container. The viscosity of such products comprises the range from about i to about 1500 centistokes. Examples of such fluid products are dairy cream, dessert toppings, purees, shaving soap, paints, lacquers, hair sprays, perfumes, cosmetic preparations, cocktail components, fruit juices, flavors, adhesives, cleaners, etc. Products containing particulate matter may also be loaded as, for example, paint or lacquer containing metallic glitter" such as aluminum flakes, purees containing food particles such as tomato pulp, cosmetic preparations containing talc, etc. lt is understood that the particle size must be small enough to pass through the mixer.
Dimensions, stream velocities and pressure drops are critical dependent variables which must be calculated for each mixing and loading application. The loading time (time to load one container) is also usually critical (for high vapor pressure propellants) and must be found empirically for each loading application.
By low vapor pressure propellants are meant those which condense at use temperatures at pressures below the burst or,
allowed upper pressure of the container. Those which do not condense are high-pressure propellants.
The total pressure of the system as packed in the container depends not only on the vapor pressure of the propellant but also on the solubility of the propellant in the medium with which it is packed. For example, hydrocarbon propellants are essentially insoluble in aqueous media. Thus the gauge pressures developed in a container loaded with an aqueous product and a condensing hydrocarbon propellant will be close to the pressure the liquefied propellant would exert if it alone were in the container. On the other hand, the gauge pressure in a container packed with a hydrocarbon propellant and an organic solvent, eg a lubricating oil, would be much lower because of solubility of the propellant in the solvent. Fluorinated propellants are regarded as insoluble in water but soluble in some organic materials such as butter fat. Carbon dioxide and nitrous oxide are high-pressure propellants and are slightly soluble in aqueous media.
The following table shows the vapor pressures of the propellants listed above. Thus the pressures shown are approximately those one would expect to measure in a dispenser containing liquefied propellant and a fluid to be dispensed in which the propellant is insoluble. Were the propellant soluble in the fluid, the observed pressures would be lower by an amount proportional to the solubility.
745.3 Critical temp. 97.7 F. 837.8 Critical temp. 87.8 F.
Nitrous oxide Carbon dioxide lsobutane 30.3 Critical temp. 94.7" F. Propane 1096 Critical temp. 259.8 F. Nitrogen Veryhigh pressure-noncondensable at temperatures above Z32.6 F.; its 3 critical temperature.
Commercial dispensing containers vary considerably in their ability to withstand internal pressure. For example, small pressurized glass dispensing bottles now in the trade are customarily pressured to not more than about 20 p.s.i.g. at room temperature. The bottles are usually coated with polyvinyl chloride as a safety precaution. On the other hand, sheet metal dispensing cans will withstand much higher pressures.
The generally accepted bursting pressure for common 3-, 6-, and l2-fl. oz. sheet metal dispensing cans is about 2l0 p.sii.g.; that for l6-, 20-, and 24-fl. oz. cans is about 185 p.s.i.g.
The Interstate Commerce Commission regulates the loading and allowable pressures in dispensing containers in interstate commerce as shown in Agent T. C. Georges Tariff No. 19 (issued Aug. 5, i966) par. 73.306 (pp. 99,
Compliance with regulation 73.306 (3) ii, which states, Pressure in the container must not exceed 180 p.s.i.g. at F.," is illustrated below in Example 3. Dichlorodifluoromethane is an insoluble (in water), condensable propellant (i.e. most of the propellant in the can is liquefied). Therefore, the gauge pressure of the can will be essentially the vapor pressure of the propellant (the water contributes little to pressure). The vapor pressure of this propellant at l30 F. is seen in the table above to be 181 p.s.i.g., slightly over the allowable upper limit. Mixture of dichlorodifluoromethane with lower vapor pressure 1,2- dichlorotetrafluoroethane, another insoluble (in water), condensable propellant, brings the total gauge pressure below the maximum allowed by the ICC.
The pressures of mixtures of insoluble condensable propellants can be estimated by application of Raoults Law which states that in an ideal case the partial vapor pressure of a constituent is proportional to its mole fraction in the liquid. There are also means for estimating overall pressures in systems in which the propellant is soluble in the fluid to be dispensed. In practice, it is generally more satisfactory to arrive at correct pressures in such systems by trial and error.
The high-pressure propellants, i.e. those which will not condense at pressures below the allowable pressure of the container, pose special problems. For example, nitrogen, which is only slightly soluble in any fluid medium, must be used only in small amount either alone or in mixture with other propellants of lower vapor pressure or must be used in a very strong container, impractical for ordinary dispensing of fluid products.
Nitrous oxide and carbon dioxide are high-pressure propellants which, however, are soluble in aqueous medium, the most common fluid to be dispensed. Frequently, however, it is impossible to compress enough propellant of this kind into a practical dispenser to expel the contents, without exceeding the upper pressure limit of the container. It is, therefore, generally preferred to mix these propellants with lower pressure, usually fluorinated, propellants.
Even though solubility of the above propellants alone or in mixture with, for example, insoluble propellant acts to lower the dispensers gauge pressure, it does not follow that they can be loaded with the same ease as are the liquefied propellants. This is so because solution of the soluble propellant requires time and, in the process of the prior art, shaking of the container.
in loading propellant mixtures containing one or more soluble high vapor pressure propellants, the loading time fixes the other variables and thus must be considered first. When the pressurized mixture is injected into the container, dissolved propellant immediately begins to come out of solution and to collect in the free space of the container during the early part of the filling cycle. These gases are compressed in the head space as the container fills. Should the container be filled slowly, then high pressures analogous to the initial pressures of the conventional process are developed.
It has been found that initial pressure can be minimized in the process of the invention by filling containers rapidly so that the dissolved gas has little time to come out of solution. The examples below demonstrate the experimental estimation of the maximum allowable filling time for various containers and charging mixtures.
The designer in considering optimum filling time will balance. within the safe maximum filling time, considerations of output rate and the cost of pressurizing the propellant and the fluid or semifluid product.
Liquefied propellants with vapor pressures less than the containers allowable pressure can be loaded by the process of the invention at any convenient rate whether the propellants are soluble or not. Having established the filling time, the designer fixes the inside dimensions of the, preferably circular cross section, upstream portion of straight run conduit 14 of the T-mixer, such that flow is definitely turbulent. Turbulence begins at a Reynolds number (N of about 2,100. However, a value of at least about 3,000 is preferred. Velocity and Reynold's number having been determined, the required value for D,, the inside diameter of the circular upstream straight run cross section is easily calculated from any of the following three relations (in consistent units):
D upstream diameter of conduit 14 V fluid or semifluid product linear velocity G fluid or semifluid product mass velocity V,p
W weight rate offluid or semifluid product flow p fluid or semifluid product density n, fluid or semifluid product viscosity N Reynolds number in upstream portion of conduit 14 The diameter D of the preferably circular cross section of the side run conduit 16 at junction with the straight run is then determinable since the mass velocity (V 1 of the preferably liquid propellant should be about 2.7 times (:0.7) the mass velocity (V,p of the stream in the straight run for best mixing results. [Chilton and Genereaux in Trans. A. I. Ch. E., 25, 102-22 (1930), reported 2.7 to be the optimum ratio for gases. It has since been found that the same ratio is also applicable for liquids] Both lower and higher ratios decrease the efficiency of mixing. Higher ratios cause the propellant stream to cross the straight run stream and move without mixing along the far wall. A smaller ratio causes the propellant stream to move without mixing along the near wall. At much higher (and impractical) ratios, mixing again becomes efficient.
The section of the straight run conduit 14 downstream from the junction with the side run conduit 16, hereinafter called the tailpipe, is ordinarily of the same diameter as the section upstream. However, if there is a large increase in viscosity of the fluid or semifluid product upon mixing with the propellant or propellant mixture, the downstream section's diameter D should be modified to insure turbulent flow according to the above equation.
1f the Reynolds number in the tailpipe is at least about 3,000, then a length of at least 8 diameters, preferably at least 10 diameters, is sufficient to insure substantially complete mixing (at least about 97 percent).
Because of greater mixing efficiency, it is preferred to deliver the propellant stream to the straight run section 14 in the liquid state. This consideration may affect the choice of pressure on the propellant stream. Generally, however, the pressure drop required for the delivery of the mixture to the container within the allowable filling time, rather than the condensation pressure of the propellant, is controlling.
The required pressure drop along the path of the propellant stream 16 can be calculated for various velocities (and thus filling times) by the approximate equation following (in consistent units):
man e i where:
V, fluid velocity in the straight run V fluid velocity in the tailpipe V fluid velocity in the side run p,, p p fluid densities g dimensional constant (gravity) AP= pressure drop in the examples, the tailpipe (downstream section of conduit 14) was attached directly to foam valve-equipped dispensing cans for through the valve loading. The tailpipe 28 of the T-mixer embodiment of FIG. 2 was inserted into the tube of the valve 24 and a rubber ring seal 26 closed the space between the tailpipe and the tube as shown in FlG. 2. In using the embodiment of FIG. 3, the tube of the valve 24 itself served as the tailpipe. Closure was also effected by ring seals at 26 and 30. Since the inside diameter of the effective tailpipe" section was greater in the latterassembly, higher throughputs could be accommodated and larger dispensing cans could be filled without high initial pressure.
In Examples 1, 2 and 3, pressure drops through slots in the foam valve itself were insignificant. When a more viscous vegetable fat topping was loaded in Example 4, the pressure drop though the valve became significant and was considered in selecting an overall pressure drop.
EXAMPLES The critical dimensions of the mixers used for the following examples, derived according to criteria presented above,
Figure 2 Embodiment Passageway l4:
Inside Diameter (D, and D three thirty-second inch-no change in diameter throughout the length. Length: for convenience 2 /4 inches (design criteria required only 1% inches). Side Conduit 16: D 0.015 inch diameter.
Figure 3 Embodiment Filling 1 Propellant time, Fluid AP, AP, lbs./ Valve AP, sec. lbs./sq. in. sq. in. lbs/sq. in.
Included in fluid and propellant'AP-values.
EXAMPLE 1 (Using Figure 2 Embodiment) This example demonstrates the loading of commercial Clayton foam valve (as described in US. Pat. No. 3,132,774) equipped dispensing cans of various sizes with pure water and a. mixture 'of octafluorocyclobutane, an insoluble propellant, and nitrous oxide, asoluble propellant. The results are approximately those which one could expect with aqueous-based products generally.
It is seen that the initial pressure is roughly proportional to the loading time because of flashout at longer loading times.
Containers were loaded through the valve to octafluorocyclobutane-flashed cans.
Solenoid valves were installed close to the T-mixer in the straight run and in the side run lines. An electric timer opened the valves simultaneously for fixed periods.
Can pressure was measured by a pressure gauge attached to the Clayton valve.
A. 16 fluid ounce, water pressure 200 p.s.i.g.
I3. 12 fluid ounce, water pressure 200 p.s.i.g.
Filling time, sec 1.0 2. 5 3.0 Net weight of contents, grams. 120 216 245 Approx. percent full..- 30 54 61 Initial pressure. p.s.i.g 5'.) 125 143 Pressure after 1 inn, p.s.1.g 102 128 Pressure after 24 hrs., p.s.i.g. 40 F 6U 92 C. 6 fluid ounce, 200 p.s.i.g. water pressure Filling time, see 1 1. 5 2. O 2. 5 2. 7 Net weight of contents, grams. 101 130 125 177 186 Approx. percent full 45 58 56 80 83 Initial pressure, p.s.i,g 43 97 125 151 166 D. 6 fluid ounce, 250 p.s.i.g. water pressure Filling time, sec 1.0 1. 5 1. 7 1. 9 Net weight of contents, grams 115 168 185 200 Approx. percent full 52 75 83 90 Initial pressure, p.s.i.g.. 73 126 135 158 Pressure after 24 hrs., p.s.i.g., 40 F 39 61 71 86 E. 3 fluid ounce, 250 p.s.i.g. Water pressure Filling time, sec 0.8 1.0 1.1 1. 2 Net weight or contents, grains 97 117 122 127 Approx. percent full 67 81 84 88 Initial pressure, p.s.i.; 104 109 131 146 Pressure after 24 hrs. p.s.i.g.. 40 F 63 1 Some bulging in cans from overpressure.
EXAMPLE 2 (Using Figure 2 Embodiment) Filling Time, sec 0.8 1. 1. 2 1. 3 1. 4 Net Weight of Contents, grams 89 99 114 121 128 Approx. percent full 61 68 79 84 88 Initial pressure, p.s.i.g.. 89 93 109 126 126 Pressure after 24 hrs., p.s.i.g., 40 F 60 62 67 81 79 Number of Containers 2 2 8 8 14 Overrun (percent) was measured on product from two isecond filled cans before storage. Results were 276 percent and 285 percent. Overrun of band-whipped cream is generally about 200250 percent. Overrun is computed as follows:
[volume of foam (cc.) wt. of foam (gms.)] 100 Wt. of foam (grams) The quantities for the calculations were obtained by filling a tared container of known volume and weighing the filled container.
Seven cans loaded as above in 1.4 seconds were stored at 40 F. and seven other cans were stored in a conventional food freezer. At various times after loading random cans were removed, equilibrated to 40 F., and stiffness and drainage were measured. After testing, the cans were returned to the refrigerator and to the freezer. Thus, all cans in the freezestorage series except the first underwent repeatedrefreezing.
The stiffness of dispensed whipped cream was measured with a modified Model A Curd Tension Meter manufactured by the Cherry Burrel Corporation of Cedar Rapids, Iowa. The modification consisted in replacing the curd knife with a 1 square inch circular plunger. Stiffness of hand-whipped cream is generally about l50200.
Drainage is expressed as the volume'of drained liquid (cc.)
per gram of foam in l hour. The measurement consists in placing a convenient amount'of foam on a tared 8 mesh screen, reweighing to estimate the weight of the foam, and allowing the screen to stand for 1 hour on a funnel. The fluid which drains from the screen is collected and its volume is measured.
Stored at 40 F.
Time After Packaging Drainage (1 hour) (days) Stiffness (cc/gram) 2 200 0 s 230 o 7 230 0 l0 230 0 I2 230 I 0 I7 250 0 19 220 v o Stored Frozen Time After Packaging Drainage (l hour) (days) Stiffness I (cc./gram) 2 225 0 5 240 0 7 340 0 i0 340 0 l2 320 0 i7 330 0 I9 320 Storage at freezing temperature increased the stiffness of the whipped cream. The stiffness was considered in all cases to be satisfactory, and all products had the appearance. of conventionally whipped cream.
upper limit for commercial shaving soap dispensing con-.
tainers, the foamed product was not packaged but was collected and examined at atmospheric pressure. The foam was stable and had good cell structure. (See earlier discussion regarding ICC regulations).
In a second experiment a propellant mixture of 57 wt. percent dichlorodifluoromethane and 43 wt. percent 1,2-
dichlorotetrafluoroethane was used. The vapor pressure of this propellant system is 57 p.s.i.g. at room temperature and the mixture could be safely loaded into 12 fluid ounce commercial dispensing cans via the Clayton foam valve. An average net weight of 300 grams, corresponding to 77 percent full, was charged into the cans in 2.5 seconds.
The dispensed foam was of good quality.
EXAMPLE 4 (Figure 3 Embodiment) Charging of Pressure Containers with Vegetable Fat Topping:
A typical vegetable fat topping consisting of the following ingredients was prepared.
Components l, 2, and 3 were melted and mixed together. A mixture of components 4, 5, and 6 was added to one-half the total water. The water mixture was heated to 160 F. and while being stirred, the melted mixture of components 1, 2, and 3 were added. After stirring for minutes more, the mixture was cooled to 100 F. and homogenized at 800 p.s.i. Component 7 was dissolved in the remaining water with slight heating and blended with the rest of the components.
The topping mixture and chloropentafluoroethane propellant, each supplied to the T-mixer at 250 p.s.i.g., were charged through Clayton foam valves to commercial 24-ounce dispensing cans.
Overlnitial Drainage, run, Stili- Net wt.,
Filling time, sec. pressure 2 hr. percent ness grams The overrun was modest. Had greater overrun been desired more propellant would have been charged to the containers by supplying the propellant at higher pressure to the T-mixer and/or by enlarging the side run orifice within design criteria.
The foregoing description has been given for clearness of understanding only and no unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described, for obvious modifications will occur to those skilled in the art.
1. In a process for loading a pressurized dispensing device through a valve with fluid products and normally gaseous propellants, the improvement comprising continuously feeding and substantially premixing streams of such fluid product and propellant under turbulent conditions in close proximity to said device while en route to loading,
1. developing the ratio of the mass velocity of the gaseous propellant to the mass velocity of the fluid product to be 2.7:07 or greater,
2. causing the turbulence of the gaseous propellant and the fluid product to be at least about 3000 Reynolds number with a mixing section of at least 8 diameters in length and providing the gaseous propellant and the fluid product entry lines to be of sufficient size to permit loading the container to at least 70 percent of capacity before the pressure in the container reaches a value that is about twice the equilibrium pressure of the loaded container.
2. claim 1 wherein said propellant is in a liquid state.
3. Claim 2 wherein said propellant has a vapor pressure greater than said device's allowable pressure and wherein said streams are mixed and loaded rapidly enough to prevent substantial vaporization of said propellant.
4. Claim 2 wherein part of said premixing occurs within said valve.
5. Apparatus for continuously feeding and substantially premixing streams of fluid product and propellant in close proximity to and while en route to being continuously loaded into a pressurized dispensing device through the valve thereof comprising: A housing; a substantially straight passageway extending therethrough for continuously receiving and conveying said fluid product stream through said valve; inlet means in said housing opening into said passageway at substantially right angles for continuously receiving and conveying said propellant stream into said passageway; and a cylindrically shaped means located in the downstream end of said housing adapted to slidably receive said valve such that said valve and passageway are in register; said passageway between said inlet means and said dispensing device extending at least 8 to 10 diameters in length; said passageway having no valve for flow restriction; said inlet means and said passageway between said inlet means and said dispensing device having diameters such that a predetermined turbulent flow is achieved for a predetermined loading velocity.
6. Claim 5 wherein the diameter of said passageway for a given fluid product and desired degree of turbulence is directly proportional to the required loading velocity as determined by the relationship D=(4w)/(1ruN where w is the weight rate of fluid product flow, p. is the fluid product viscosity and N, is the Reynolds number.
7. Claim 6 wherein said housing is further provided with a cylindrical, elongated passageway section concentric within and extending beyond said recess which is adapted to fit within said valve when the valve is positioned within said