US2785537A - Freon filling method and apparatus - Google Patents

Description

March 19, 1957 Filed Sept. 28, 1954 A. B. MOJONNIER FREON FILLING METHOD AND APPARATUS 2 Sheets-Sheet 2 FREON FILLING METHQD AND APPARATUS Albert E. Mojonnier, Chicago, ill.

Application September 28, 1954, Serial No. 458,729

6 Claims. (Cl. 621) This invention relates to a method and. apparatus for filling containers with. a measured. quantity of liquefied gas.

Various products, commonly referred to as aerosols, are presently packaged in pressurized containers with a compressed liquefied gas which serves as a propellant.

The propellant used is a gas, such as Freon, which hasv a vapor pressure higher than normal atmospheric pressure, at the temperature which the product is to be dispensed, so that the propellant maintains the product in the container under its elevated vapor pressure. When the dispensing valve on the container is opened, the product is dispensed through the valve under the pressure in the container.

The amount and type of propellant used varies with the product being dispensed and it is therefore necessary to provide a dispenser which is adaptable to accurately dispense different quantities of propellant into the container. One method of filling uses refrigeration to cool the ingredients and the propellant to a temperature at which the propellant is a liquid at normal atmospheric pressures. This method is satisfactory for packaging ingredients which could be subjected to low temperatures: without freezing; it is not adaptable for loading. those products containing cold-sensitive. ingredients.

It has also been proposed to use a pressure filling apparatus for loading measured quantities of the propellant into the containers. Such dispensers include a measuring cylinder and an adjustable stroke piston for discharging the propellant from the cylinder into the container under pressure. In order to dispense an accurately measured quantity, it is necessary that the measuring cylinder be filled with the propellant in its liquid form only, and not part liquid and part gas. In prior fillers, the propellant was introduced into the measuring cylinder directly from the shipping drums in which the propellant was under its own vapor pressure. It has been ascertained that the propellant, under its own vapor pressure, partially expanded as it entered the measuring chamber and this pro duced variations in the quantity of propellant measured by the pressure filler and therefore caused variations in the quantity of propellant dispensed into the cans.

An important object of this invention is: the provision of an improved apparatus for dispensing measured quantities. of a propellant into aerosol containers.

Another object of this. invention is the provision of an apparatus, in accordance with the foregoing object, which will dispense the propellant at the ambient. tempera ture so that the aerosol concentrate is not subjected to freezing temperatures.

A further object of this invention is the provision of an apparatus including a pressure filler for dispensing. measured quantities of propellant into containers, with a novel pump apparatus for elevating the propellant pres sure befiore being introduced into the pressure filler to a point well above the vapor pressure of the propellant at the ambient temperature thereby preventing expansion of the propellant as it enters the pressure filler whereby the 2,785,537 Patented Mar. 19, 1957 latter receives and dispenses an accurately measured quantity of the propellant in its liquid form.

Still another object of this invention is the provision of an apparatus, in accordance with the foregoing object, in which the pump is operated in accordance with the rate at which propellant isdispensed, thereby preventing re circulation of the propellant by the pump and consequent heating of the propellant.

These, together with various ancillary objects and advantages of this invention will be more readily appreciated, as the same becomes: better understood, by reference to the following detailed description when taken in connection with the accompanying drawings wherein:

Fig. l is a diagrarmnatickview of the propellant dispensing apparatus;

Fig. 2 is a longitudinal sectional view through the pressure dispenser; and

Fig. 3 is a longitudinal sectional View through the pumping apparatus for delivering propellant under pressure to the filler.

Reference is now made more specifically to the accompanying drawings and in particular to Fig. 2 thereof wherein there is illustrated one type of pressure filler 10 for filling the containers such as the can '1" (see Fig. 1) with propellant. The filler includes a crimper bell 11 having a downwardly facing opening 12 shaped to receive the upper end of the container to be filled. Such con tainers, as fed to the filler I0, are partially filled with aerosol concentrate and have a normally closed dispensing valve 8. The pressure filler is arranged to force the propellant such as Freon, under pressure, through the container valve and into the container. The container valve recloses, after the external pressure from the filler it) is released, and the propellant partially vaporizes in the container to establish its vapor pressure therein and maintain the concentrate at that pressure.

A valve adapter i2, having. a valve engaging end 13 shaped to sealingly engage the valve on the container, is removably disposed in the bore 14 to permit interchanging of the valve adapters for the several different types of dispenser valves on the containers. In the form of the filler shown in the drawings, the adapter has a flange 15' adapted to be seated on the shoulder 16 and a check valve including a valve guide block 17 is disposed in the bore 14 in overlying relation to the adapter. A valve plate 18 having a downwardly facing valve seat 19 is mounted in the bore 1'4 and guidably supports the stem 21 of the valve 22. A spring 23' is provided to normally urge the valve to its closed position and is arranged to permit opening of the valve when the pressure applied to the upper side: thereof exceeds a preselected value to be described more fully hereinafter.

The crimper bell 11 is attached to the lower end of the measuring cylinder 25' and communicates therewith through a passage 26. A piston 27 is :reciprocably disposed in the cylinder and the piston rod 2-3 thereof extends through the cylinder head 29. in order to selectively vary the amount dispensed by the filler, provision is made for adjusting the piston stroke and for this purpose, the rod 28 is externally threaded and carries a collar 2? which is adjustable therealong. The collar is locked in its adjusted position by a plug and set screw assembly 31 and is arranged to engage the cylinder head on the dispensing. stroke of the filler to limit the downward travel. of the piston and thus control the amount of propellant dispensed in. each stroke. Alternatively, the filler could. be arranged to adjustably limit the travel of the piston on the upstroke thereof duringwhich the measuring. cylinder is filled. Propellant is introduced into the measuring cylinder from a conduit 33 which communicates with atransverse passage S5 at the upper end of the rod, an axial passage 36 being provided in the nod and piston to communicate passage 35 i with the measuring cylinder.

The piston 27 is reciprocated in any desired manner and, as shown in the drawings, is connected through a coupling 38 to the piston rod 39 of a pneumatically operated motor 41 (see Fig. 2).

, Heretofore, the liquefied gas propellant has been introduced into the measuring cylinder directly from the shipping drums in which the propellant is in liquid form under its vapor pressure. When filling containers in this manner, variations in the quantity of propellant dispensed into the cans by the filler was noted. This was determined to be caused by the vaporization of a portion of .the liquefied gas as it was introduced into the measuring cylinder. Therefore, at the start of the filling cycle, the measuring cylinder was only partly filled with liquefied gas, the remainder being the vaporized propellant. When the filler piston was thereafter moved in a dispensing stroke, the vaporized part of the gas was merely compressed, and a charge of liquefied gas, less than the adjusted volume of the measuring cylinder, was introduced into the cans.

In order to prevent this flashing of the liquefied gas as it enters the pressure filler, provision is made for compressing the liquefied gas, as it is taken from the. shipping drums, to a pressure Well above the vapor pressure of the gas under ambient temperatures. Consequently, the small reduction in pressure on the liquefied gas, as it is fed into the pressure filler, is insufficient to lower the pressure on the propellant below the vapor pressure thereof, so that no expansion occurs.

As illustrated in Fig. 1, the liquefied gas is withdrawn by a pump 44 from the shipping drum (not shown) through a conduit 45, shut-off valve 46, check valve 47, and conduit 48. The check valve 47 is arranged to permit flow from the drum to the pump and closes to prevent return flow. A pressure gauge 49 is provided for checking the Freon supply pressure. The pump is driven by an hydraulic motor 52 which is arranged so that the operation of the pump is stopped when the discharge pressure reaches a preselected value. This eliminates the necessity of bypassing the excess pump discharge fluid, when the discharge pressure reaches a preselected maximum, as occurs in continuously operated pumps. Such by-passing of the discharge of the pump causes heating of the fluid passing through the pump and, in the case of the liquefied gases, would tend to increase the vaporization of the propellant as it entered the filler, thereby reducing advantages of compression in the pump.

The compressor pump 44 illustrated is a reciprocating type pump and the fluid motor used for operating the pump is also of the reciprocating type, it being understood that other pump and motor arrangements, such as a rotary type fluid pump and a rotary fluid motor, may also be used. The pump 44 is of conventional construction and includes a cylinder 53 communicated at its lower end with propellant inlet conduit 48. A piston 54 is disposed in the cylinder and carries a poppet valve 55 arranged to close on the up-stroke of the piston and to close on the down-stroke of the piston. The piston is connected by a piston rod 58to a tube 59 having a sealed lower end 61, which tube extends through the packing gland 62 at the upper end of the pump cylinder 53. The pump is of the double acting type and the tube 59 has a smaller crosssection than the pump cylinder53 so that on the up-stroke of the pump, a volume of the fluid above the piston 54, equal to the difierential in the displacements of the piston 54 and the tube 61, is delivered through the pump discharge passage 63. On the downstroke of the pump, the fluid below the piston is forced through passage 56 ports 57 in the piston. The tube 59 entering the pump cylinder displaces a volume of the fluid above the pump cylinder equal to the displacement of the tube.

The fluid motor is conveniently directly connected to the pump and includes a cylinder 71 connected by legs 72 to the upper end of the pump cylinder. The tube 59 extends upwardly through the sealing ring "it? into the motor cylinder and is formed with a valve seat 73 at the upper end thereof. A piston head 74 is secured to the upper end of the tube and has passages 75 extending therethrough. A double acting valve is mounted on the piston head and includes an annular flanged valve ring 76 slidably mounted on the piston head arranged to close the ports 75 when the ring is raised. The ring is connected by rods 77 to an exhaust valve 78 which cooperates with the valve seat 73 to control fluid flow through the tube 59 to the exhaust ports 79 located intermediate the ends thereof. A spring 81 is located adjacent the upper end of the motor cylinder and engages the exhaust valve 78, when the piston reaches the upper end of its stroke, to close the exhaust valve and move the valve ring 76 away from ports 75 to open the latter Compressed air, which is provided from a suitable compressor through air inlet conduit 82 (see Fig. 1), an adjustable pressure regulator 83, shut-off valve 84 and conduit 85, then flows through ports 75 into the motor cylinder above the piston head 74. This forces the piston head '74- and tube 59 down. When the piston head reaches the lower end of its stroke, a disk 86 carried by the piston head engages the lower end of the motor cylinder and moves the valve ring 76 upwardly to close the ports 75 and open the exhaust valve 78. The compressed air then urges the piston head upwardly.

The pressure developed by the pump is thus determined by the air pressure supplied to the fluid motor and the relative areas of the pistons in the fluid motor and pressure pump. In the apparatus illustrated, the areas of the two pistons are made equal so that the fluid motor will operate the pressure pump until the discharge pressure on the propellant delivered by the pump equals the air or other fluid pressure applied to the motor. Under those conditions, the pressure developed by the motor equals the opposing pressure in the pump, and the motor operation stops. As soon as the pump discharge pressure is released, as when propellant is delivered to the filler, the pump will again operate to maintain proper pressure on the propellant.

The pump apparatus is so arranged as to permit adjustment of the discharge pressures on the propellant, as is necessary in the handling of propellants having different vapor pressures. This is achieved without the necessity of regulating or otherwise throttling the pump discharge which would tend to cause heating of the propellant. Since the motor only operates until the pump discharge pressure equals the air pressure supplied to the motor, or bears a predetermined ratio thereto determined by the areas of the pump and motor pistons, the pump discharge pressure is easily controlled by varying the pressure applied to the fluid motor, as by the adjustable pressure regulator 83.

Provision is made for smoothing the pulsations from the pump 44. The output of the pump is delivered through passage 63 and check valve 87, which is arranged to prevent return flow to the pump. The fluid flowing through the check valve passes through conduit 88 and through a manual shut-01f valve 89 to the upper end of an accumulating tank 91. A pressure gauge 92 is provided in the line 88 to permit checking of the pressure in the accumulating tank. The propellant from the lower end of the tank is passed through conduit 93, shut-off valve 94, conduit 95, check valve 96 and conduit 33 to the pressure filler. Check valve 96 is arranged to prevent return flow from the filler to the accumulating tank.

An air cushion is provided in the accumulating tank 91 and for this purpose, a charge of compressed air is supplied from the air compressor, through conduit 101, adjustable pressure regulator 102, shut-0E valve 103 and bleed-off valve 104 to the top of the tank. A high pressure arenas? glass: gauge 105 is provided on the tank to permit checking the liquid level in the accumulating tank.

As previously described, the filler piston may conveniently be operated by a pneumatic motor 41. As shown in Fig. 1, pressurized air issupplied alternately to opposite ends of the motor cylinder-through conduit 107, multipleport valve 108 and conduits 109* and. 110. Valve 108 may be of any conventional construction which, one position thereof, will apply pressurized air fromconduit 107 to. conduit 110 and simultaneously communicate conduit 109 to the exhaust conduit 111;, and which, in the other position thereof," connects. conduit 107 to conduit 109, and connects conduit 110 to exhaust conduit 111. An air bleed-ofi valve 115 is connected by conduit 116 to the passage 35 in the pressure filler to permit bleeding of air from the filler 10.

The operation of the pressure filling system will now be described in filling containers with a propellant such as Freon-12 which has a vapor pressure of about 70 p. s. i. at 70 F. The air regulator valve 83 is set to a preselected pressure such as 135 pounds per square inch gauge, well above the vapor pressure or the liquefied gas at the ambient temperature. Valve 46 is then opened to allow the propellant to flow from the drum, through conduit 45 into the pressure pump 44 and valve 89 is opened to allow propellant to flow from the pump to the accumulating tank. Valve 84 is then opened to admit air to the fluid motor 52 which operates to fill the accumulating tank and compress the 'air above the Freon in the tank. When the accumulating tank has been filled to a preselected level, valve 84, which controls the supply of compressed air to the fluid motor 52, is closed to stop the motor. The valve 103 is then opened and pressure regulator 102 set to apply head pressure on top of the liquefied gas in the tank, which pressure is measured on gauge 92. Valve 84 is then reopened to apply air pressure to the fluid motor 52 which operates until the propellant pressure in the accumulating tank is equal to the air pressure of 135 pounds per square inch gauge supplied to the motor 52. Valve 94 is then opened and the propellant permitted to flow to the filler. Valve 115 is then opened to bleed off any air in the filler and when the propellant begins to flow therethrough, the valve is closed.

As the propellant flows into the filler 10, the measuring cylinder moves downwardly under the pressure of the propellant until the piston 27 reaches its upper limit. The pressure on the propellant then builds up in the measuring cylinder until it equals that in the accumulating tank, at which pressure the propellant is entirely in its liquid state. The valve 108 is then operated to apply air pressure to the fluid motor 41 to urge the filler piston downwardly. During the initial portion of the stroke of the piston 28, the measuring cylinder moves with the piston until the bell 11 engages the top of the container 7. Thereafter, the piston 27 moves in the measuring cylinder to force the propellant past check valve 22 and the container valve 8 into the container. As is apparent, spring 23 is designed to hold the valve 22 closed under the pressure of the propellant from the accumulator, and opens when the pressure in the filler is raised by the piston 27 during the dispensing stroke. Check valve 96 prevents the propellant from flowing from the filler 10 to the accumulating tank, during the dispensing stroke, and opens on the up-stroke of piston 27 to admit another charge of propellant into the filler.

As the propellant is dispensed by the filler, the pressure in the tank is reduced. The air pressure applied to the motor 85 then exceeds the pressure on the propellant delivered by the pump whereupon the fluid motor 52 operates to drive the pump 44 and replace the propellant withdrawn from the tank. When it is desired to change the pressure on the propellant in the accumulating tank, as when handling diiterent propellants having different vapor pressures, the regulator 83 is adjusted to vary the air pressure supplied to the fluid motor which, in turn,

3 changes themaximum discharge pressure'of the pump 44. as previously described.

When it is desired to drain thesystem, the air and propellant inlet valves 84* and? 46 respectively are shut off. Valve103 is then opened allowing :air pressure from the main air supply line to force the propellant out of the accumulating tank as it is dispensed by" thepressure filler 10. When theaccumulati-ng tank is empty, valve 103 is closed and valve 104-opened to bleed-oflithe air pressure in the tank and. in the line to the pressure filler.

I claim:

1. In an apparatus for filling containers with a measured quantity ofliquefied gas comprising, a pressure filler including a measuring cylinder and means including a piston in the cylinder for intermittently dispensing a selectively variable quantity of liquid from the cylinder under pressure, a pump for delivering the liquefied gas to the pressure filler under a pressure greater than the vapor pressure of the liquefied gas at the ambient temperature to prevent expansion of the liquefied gas as it enters the filler, a fluid motor operatively connected to said pump to drive the latter, and means for applying fluid under a preselected pressure to the motor whereby the motor operates the pump until the pump discharge pressure bears a predetermined relation to the fiuid pressure applied to the motor.

2. The combination of claim 1 wherein said means for applying pressure to said motor includes a pressure regulator which is selectively adjustable to vary the pressure applied to the motor and thereby correspondingly vary the pump discharge pressure.

3. The combination of claim 1 including an accumulator tank connected to the pump outlet to receive compressed liquefied gas therefrom and for delivering the liquefied gas to the filler, and means for applying pressure to the liquefied gas in the accumulator to maintain the gas therein at a pressure greater than the vapor pressure of the liquefied gas at the temperature of the liquefied gas in the accumulator.

4. In an apparatus for filling containers at ambient temperature with a measured quantity of liquefied gas comprising, a pressure filler operable to measure and dispense a selectively variable quantity of liquid under pressure, a pump for compressing the liquefied gas to a preselected pressure greater than the vapor pressure of the gas at ambient temperature to prevent expansion of the liquefied gas as it enters the filler, an air motor operatively connected to said pump to drive the latter, an accumulator tank communicating with said pump to receive compressed liquefied gas therefrom and for delivering the liquefied gas to the filler, means for supplying air under a preselected pressure to said motor to thereby operate the pump until the pump discharge pressure bears a predetermined relation to the air pressure applied to the motor and the latter stops, and means for introducing a charge of air under pressure into said accumulator tank to maintain the liquefied gas therein at said preselected pressure.

5. The method of supplying liquefied gas from a shipping drum containing the gas under its vapor pressure to an intermittently operated filling apparatus arranged to measure a quantity of liquid under pressure and dispense the same comprising, passing the gas from the drum through a compressor to the filling apparatus, operating the compressor with a fluid motor to compress the gas and completely liquefy the same, and regulating the pressure on the fluid supplied to the fluid motor to a value such that the output torque of the fluid motor equals the torque required to operate the compressor when the compressor discharge pressure is a preselected pressure above vapor pressure of said gas at ambient temperatures.

6. The method of supplying liquefied gas from a shipping drum containing the gas under its vapor pressure to an intermittently operated filling apparatus arranged to measure a quantity of liquid under pressure and dis- '7 pense the same comprising, passing the gas from the drum to a compressor, operating the compressor with a fluid motor to compress the gas to a preselected pressure above the vapor pressure of the gas at ambient temperature and completely liquefy the same, accumulating the liquefied gas from the compressor in a confined zone having a capacity which is small as compared to that of the drum, maintaining the liquefied gas in the confined zone under the pneumatic pressure of a gas which is gaseous at the temperature and pressure of the liquefied gas in the zone, regulating the pressure on the fluid supplied to the motor to a value such that the output torque of the motor equals the torque required to operate the compressor when the til compressor discharge pressure equals said preselected pressure, and passing the liquefied gas from said zone to the gas at said preselected pressure.

References Cited in the file of this patent UNITED STATES PATENTS Re. 19,054 Heylandt Jan. 16, 1934 2,252,300 McGrath Aug. 12, 1941 2,252,939 McCoy Aug. 19, 1941 2,387,894 Fannin Oct. 30, 1945 2,641,399 McBean June 9, 1953 2,670,605 Van Zandt et a1. Mar. 2, 1954

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