US2217169A - Machine for forming solid carbon dioxide - Google Patents

Description

. Oct. s, 1940. RHILL 2,27,.s9

MACHINE. FOR FORMING SOLID CARBON DIOXIDE Original Filed Nov.- 29, 1937 2 Sheets-Sheet 2 attorneg Patented Oct. 8,

Reuben Hill, Los Angeles, Calif., assignor to Leo M. Harvey, La Canada, Calif.

Application November 29, 1937, Serial No. 171.048

- Renewed June 23, 1939, v

17 Claims. (Cisa-121 This inventin relates to machines tor forming solid carbon dioxide. L

In order to maintain refigeration of a container, andmore particularly one requiring trans portation, it is a common practice to sdispose the container in a pa'cking formed by blocks or ragments of ice or ot solidified carbon dioxide.

such practice consumes considerable time in preparing and positioning such packing, and the interstices between the blocks or fragments, and between the packing and the container materially detract from the refrigerant efiect and also re- Q duce the hold-over interval or period of refrigeration.

solidifying carbon dioxide, asa continuous mass,

in intimate and continuous contact with a container, so as to cool the latter with a maximum emciency and oier a maximum resistance .to sublimation. i

Another object is to provide a machine for depositing a jacket of solid carbon dioxid'e in a substantially surrounding relation to a container,

imposing a very low temperature upon the container and its contents, and eliminating the time and labor requiredin prior methods of applying refrigerant packings, and minimizing required refrigerant. e i i Another object is to form a reirigerant space between' an inner and an outer container, and toprovide for the 'delivery of liquid carbondioxide to such space, and the consequent tormation therein of a jacket orsolid carbon dloxide for maintaining a prolonged low temperature cooling of the inner container.

' A further object is to provide for a 'ready removal oi the inner container from the outer one,

to iacilitate loading or unloading of the inner container. g 40 A further object is to provide a machine comprising an enclosure wherein a container may be' `;acketed with solid carbon dioxide, said machine comprising, valve mech'anism for controlling the flow of fluid carbon dioxide to such enclosure. A further object is to provide !or a' di'scharge from such chamber in gaseous form, of such carbon dioxide as falls to solidity, and to utilize such gaseouscarbon dioxlde in precooling liquid carbon dioxide delivered to said chamber.

These and various other obj'ects are'attained by the construction hereinaiter described, and' illustrated in the accompanying drawings, 'where- 55 elevation.

Fig 1 is a view oi the improved machine in side Fig. 2 is an isometric view of a package, com prising inner and outer containers showng the inner' one partially withdrawn from the outer.

Fig. 3 is a cross sectional view, taken on the'line 3-3'of Fig. 1, and showing said containers, as inserted in a 'receiver stationaryon the ma-- chine. v

Fig. 4 is another isometric view of said package, as seen from the rear. g

Fig. 5 is a cross sectional View, taken 'on the line' 5-5 of Fig. 1, showing valve mechanism controlling the flow of liquid .carbon dioxide.

. In these views, the reference character l designates a rectangular receiver, adapted to form 'An object' of the invention is toprovide for v an enclosure for a package or receptacle com- 15 prising inner and outer containers 2 and 3, .which are also preferably rectangular; 'said receiver and the outer container are formed preferably of a heat insulating material such as are common, and the inner container is formed of sheet metal, zo sufllciently thin to readily transmit heat. Doors 4, 5, and 6 serve to give access to the front ends of the receiver I, and to the inner and o'utercontainers, said doors being preferably 'hinged and 4 The' outer con- 25 walls, and spacer blocks 8 are interiorly attached to the door .and rear wall of such container. said strips and blocks are preferably so proportioned as to provide ior equal spacing of all walls of the two containers'. V

For delivering liquid carbon dioxide into the space between the containersz and 3, one or more nozzles 9 are carried by and forwardly project from a circular manifold l0,.exteriorly secured Y to the tear wall of the receiver I, four ot such nozzles being preferablyemployed, as illustrated.

'These nozzles pass snugly through the receiver I, and project through'oversize openingsil in the rear wall of the container 3, so as to 'freely extend some distance between the sidewalls and top and bottom walls of the two `containers. Liquid carbon dioxide is delivered tothe manifold through 'a coil |2 from an expansion chamber IS, and a delivery connection ll to said chamber leads out of a housine ii !or valve mecbanism controlling the flow. It is preferred to further employ said housing as'a base for the receiver l, and to enclose the manifold o, coil l2, and expansion chamber' !3 in a hood IS, formed of heat insulating material, and preferably mounted jointly on the rear end portions of the receiver and said housing.

Valve mechanism within the housing IE (see Fig. 5) comprises a base plate I'l, a valve casing I 3 carried by such base plate, a valve member l9 controlling flow through said casi'ng, a lever 20 pivoted on the base plate at 2| and effective at one end on the nee'dle` va1ve,'a spring-pressed plunger 22 hearing on the other end portion of said lever, and tending to close the valve, and a lever 23 for opening 'the valve, pivoted 'on the base plate and rigidly carrying at its pivotal axis a pinion 24, meshing with a rack bar 25, slidably guided on the base plate.- An end portion of said rack bar is slotted lengthwise to accommodate a pin 25 carried by the lever 20, said slot pernitting the rack bar and its actuating lever to be returned immediately by a spring 21 to a normal position, after the valve member s has been fully unseated. For holding the valve member unseated, a. latch arm 28, pivoted at 29 on the base plate, is formed with a sear 30 and is acted upon by a spring` 3l, serving to engage the sear 30 with sear 32 on the lever 20, on shifting of the latter to its valve-opening. position. It is preferred to form the latch arm with an extension projecting through an opening 33 in the housing- I 5, said extension serving as a trip'arm to permit of manual unlatching of the valve member, if desired. The opening 33 also serves to allow the actuating lever 23 to project from the housing IS V to permit'of its convenient manipulation.

The valve mechanism further, comprises a device, mounted on the base plate l'l for automatically tripp g the latch arm 28, after a predetermined lapse of time, to permit closing of the valve. As disclosed in Fig. 5, this device employs a plunger 34, operatively engaged, at its mid portion `by one endof a. lever 35, whereof the other'end is operativ'ely connected by a link 36 to an arm 31 on the actuating lever 23. such 'connection is preferably establi'shed by engaging a pin 38 on said arm in aslot 39 of the link, thus avoiding interference with automatic' recovery by the lever of its normal position, following a Valveopening control. The lever is pivoted between its ends on the base plate, as indicated at' 40 and carries, between its pivot and link-engaging end a roller 4l, adapted to coact with the springpressed end portion of the latch arm 28" to trip the latter, responsive to a certain rocking of such lever. One end of the plunger 34 is under pressure of a coiled spring 42, whereby a piston43 on the other end of said plunger and working in a dash-pot cylinder 44, is urged toward 'an end wall of such cylinder. Adioining such cyliudeiis a chamber 43 from which a restricted pa'ssage 43 opens through said end wall, the degree of re-- strlction being preferabiy regulable by a metering A suitable liquid, preferably oil, oocu pies the space between the piston 43 and said -cylinder end wall and aso`fllls the chamber 43,

v at least to thelevel of the passage' 45. Upon 'retraction of the pisten from said cylinder end wall,

liquid may'be'freely drawn into the cylnder from ,the chamber 45,' by way of a port (Fig. 5) controlled by .a check valve 48, spr -prema to re-'- sint outfl'ow. Approach of the pistonto the cylinder end wall imposes a pressure on the liquid in the cylinder that supplements the check \valv e more. of the corks 32 will yield the piston may not approach the cylinder end wall faster than the trapped liquid escapes through the passage 46.

While any suitable source of liquid carbon dioxide may be employed, it is preferred to cradle a tank 49 of such liquid' on a stand 50 which mountsthe machine at a. convenient elevation. such tankis terminally provided with a valved fitting 5l from which a delivery connection 52; preferably flexible, leads to the valve casing 18.

To cradle said tank, as described, it is preferred to invert the tank and engage its valved end with a recessed main support 53, which is apertured to" accommodate the fitting 5l, and is equippedwith a pair of opposed trunnions 54, journaled in cross bars forming a lower portion of the stand. When thus engaged with said main support, the tank may be readily tilted to laterally rest against a bar 55 terminally engaging a" pair of hooked .keepers 56 carried .by thegstand 59 respectively surmounting said receiver and,

the hood I 64. Gas failing to form snow escapes fromthe container 3 through the openings |,l and fiows between said container and the receiver to the vent duet 51. As best appears in Fig. 4, a

channel 60 may extend in the top wall of the container 3 from the rear edge to the center portion of said wall, to facilitate the escape of gas.

A vent SI in -the bottom of the hood IS serves to discharge gas to the atmosphere. Since the gasthus passed through the hood is at very low temperature, it effectively precools the liquid carbon dioxide flowing through the expansion chamberT3' and coil I2. The chamber l3, in afl'ording the car-bon dioxide a'. limited expansion before reaching the nozzles, also exercises a precooling efl'ect. and the manifold n provides for a still further -precoolng, in affording additional expansion of the carbon dioxide. In case; for any reason, the described prvision for a free escape of gas fails to function, the resultant buildingup 'of gas pressure will disengage th duct 51 froni one or both of the flttings 58 and' 53 to relieve such pressure.

Fig.. 4* illustrates how the openings I l in the receiver 3 may-be clowd by corks 62 or the like,

after removal of 'a charged package from the ma-- china. This prevents access of relatively warm air to the charge of solid carbon dioxide, and re tains in the package cold gas 'resulting-from sublimation.. 'In case gas accumulated in a pack-` age acquires 'any considerable pressfe. one or to relieve such pressure. e V

In operation of the machine. after insertion n the receiver of one of the packages comprised by the containers 2 and 3, and after closing of'the doors 4, I, and 3, the lever 23 is downwardly rocked by 'the operator, until the sears of the latch arm' 23. and le'ver 23 interengage to latch the valve member clear of its seat. This actuatio'n of the lever 23 is further'eflective, through the link 33 and lever 33, to shift the plmger 34 from its illustrated postonxmg. 51, to a position (not shown) compressing the spring 42 and shifting the' piston 43"toward the open 'end of its. cylinder. Buch travel of the piston'draws a considerable charge in a frozen or other refrigerated state, the maof liquid into the cylinder, the 'check valve yielding to admit same. Upon release of the lever 23, the spring 42 immediately initiates a return travel of the plunger, and the time required to complete such travel is determined by the setting of the metering pin 41, since this controls -the' rate of liquid discharge from the cylinder. As the plunger complets its return travel, the roller 4! trips the latch .arm 28, and the valve member is immediately seated, responsive to the spring-pressed plunger 22.

Thus it is seen that the valve`mechanism is semi-automatic in its operation, the valve being manually opened, and automatically latched in open'position, and closing of the valve occurring automatically upon a predetermined lapse of time.

Opening of the valve establishes a flow of liquid carbon dioxide to the nozzles 9, and in its discharge into the space between the containers 2 and 3, gasiiication of the liquid follows from relief of pressure. lifhis change of .form is productive of an intense cooling effect, resulting at once in a further transformation of the major portion of the carbon dioxide into snow particles. These adhere to the spaced walls of the two containers, rapidly accumulating thereon "until the entire space is occupied by a mass of tightly packed carbon dioxide-snow. The dash-pot timing device will be regulated to automatically cut off carbon dioxide delivery upon a time lapse, sufiicient for formation of the described charge of snow.

When the machine is employed to refrigerantly charge a considerable number of similar packages, of the type shown in Fig. 2, a regulation of the timing device to suit one thereof, sufiices for all, Since the "holdoverfi or prolongation of refrigerant'efiect, is dependent on the Volume of snow with which a packageis charged by the machine, it follows that packages may be designed with difierent accommodations for snow, to pre'- determinedly differentiate their, holdover periods. Adjustment 'of the metering pin 41 permits of radily regulating the period of carbondioxide flow to conform withthe charging capacity of any particular package orlgroupof packages.

In event of failure of the automatic features of the machine, or if, for any reason, an operator desires to interrupt a package-charging operation, the exterior extension of the latch'arm 28 permits of manually cutting off the flow of carbon dioxide.

The charging of packages with a refrigerant, as-

described, is useful in various ways A package so charged assures maintenance of a predetermined ly low temperature ,within the inner container for a definite period, 'which may be predetermined to protect perishable. commodities throughout shlpment to a certain destination. The protective temperature may be above or below the freezing point of the commodities, according tothe design of the package. i

If it is necessary for a consignee to further prolong refrigeration ofi commodities delivered to him chine readily permits of such prolongationl Dehydrationof commodities by the carbon di- ;oxide is prevented by scaling of the former from .the latter, within the innermetallic container.

- While a rectangular package has been shown and described, it is apparent that the receiver I may be designed to accommodate packages of any other shape.

The invention is presented as including all such modifications and changes as come within the scope of the following claims.

What I claim is: r

1. A machine for forming solidified carbon dioxide comprising a chamber for receiving a package formed with a space for the reception of the refrigerant, a .nozzle 'for discharging carbon dioxide into said space, a duct for delivering carbon dioxide to the nozzle, a valve controlling the nozzle, means normally urging the valve to itsclosed position, a latch operable to hold the valve open, a time controlled device for releasing the latch after a predetermined interval of time, and means for opening the valve operable to condition said device for operation.

2. A machine for forming solidified carbon dioxide comprising a chamber for receiving a package formed with a space for the reception of the refrigerant, a manifold at the exterior of the chamber, spaced nozzles communicating With the manifold and adapted to discharge into said space,'a hood housing the manifold, a Conduit conducting carbon dioxide to the nozzles and 'passing through the housing, a valvecontrolling in the conduit.

3. A machine for forming solidified carbon dioxide comprising a chamber for receiving a package iorrned with a space for the reception of the refrigerant, a duct for delivering carbon di-.

oxide to said space 'to refrigerate' the same, a coil interposed in the duct, a valve controlling the duet, and an automatic control mechanism for the valve.

4. A valve mechanism comprising a valve, a control lever for the valve,'spring means acting 'on the lever to close the valve, a shiftable part 'for Operating the valve, a latch releasably engageable with the part to hold the valve open,' 'and time delay means for retardantly releasing the latch,

5. A machine for forming solid carbon dioxide comprising a chamber wherein the solidification occurs, me'ans for conduc'ting fluid carbon dioxide to the chamber, a valve controlling the conducting means, means normally closing the valve, a latch for holding the valve open, a timing mechanism for releasing the latch after a predetermined time interval, and a common means for opening the valve and conditioning said timing mechanism for operation.

6. A machine for forming solidified carbon dioxide comprising a chamber for receiving a package forme of the refrige ant, said chamber'having an admission opening through which the package may be inserted and withdrawn, a. closure for the opening, a. nozzle discharging in the chamber positioned to supply carbon dioxide to said space when the package is arranged in the chamber, and 'means for conducting carbon dioxide to the nozzle.

. `7. A machine for refrigerating packages comprising a chamber forlreceiving a, package, nozzle means for discharging fluid carbon dioxide into the package' in the chamber, a line .conducting carbon dioxide to the nozzle* means, valve' means' controlling said line, means normally yieldingly closing the valve means, means for opening the valve means, and means made' operative by actuation of the last named means; for delaying.

the cloing of the valve means.

'8. A machine for refrigerating packagescomprising a chamber for receiving a package, nozzle means for discharging fluid carbon dioxide into with a space for-the reception the package in the chamber, a line conducting carbon dioxide to the nozzle means, valve means controlling said line, means.normally yieldingly closing the valve means, means for opening the valve means, and dash pot means made operative by actuation of the last`named means for delaying the closing of the valve means.

9. A machine for rei'r'igerating packages com'- prising a chamber for receiving a package, nozzle means for discharging fluid carbon dioxide into the package in the chamber, a line conducting carbon dioxide to the nozzle means, valve means controlling said line, means normally yieldingly closing the valve means, Operating means for opening the valve, time delay means for delayingthe closing of the valve means, and an operative connection between the Operating meansand the time delay means conditioning the time delay means for operation when the valve means is opened and f'ein'g the Operating means for return upon conditionin of the time delay means.

10. In a device tor !orming s'olidifled carbon dioxide, nozzle means for discharging carbon dioxide, means !or conducting fluid carbon dioxide to the nozzle means, valve means controlling the -conducting means, means normally yieldingly holding the valve .means closed, releasable means !or holding the valve means open, Operating means for opening the valve means' and putting the releasable holding means into operation, and time delay means tor releasing the releasable holding means at the end of a predetermined interval of time.

11. In,a device for forming solidifled carbondioxide, nozzle means for discharglng carbon dioxide, means for conduct'ing fluidtcarbon dioxide to the nozzle means, valve means controlling the conducting means, means normally yieldingiy holding the valve means-closed, releasable means for holding the valve means open, Operating means for openingthe valve'means and putting the releasable holding means into operation, and time delay means 'for releasing the releasable holding means at the end of a predetermined interval of time, the time delay means including manually regulable means for varying said intervaL 12. A machine -for refrigerating a package I) comprising a receiver i'or the package, nozzle means for' discharging carbon dioxide into the ackage when the package is in position in the eceiver, a line conducting fluid carbon dioxide to the nozzle means, means interposed in said line allowingpartial expansion of the carbon dioxide, a housingenclosing said interposed means. and means tor conducting the carbon dioxide to the nozzle means, a coil interposed in said line,

a housing enclosingthe coil, and means for conducting the carbon dioxidethat falls to solidify in the package i'rom 'the receiver to the housing I to cool the coil.

14. In a device for !orming solidifled carbon dioxide, discharge means for discharging the carbon dioxide, valve means for controlling the discharge means, means urging the valve means to the closed position, Operating means for open- 'ing the valve means, releasable means Io'r holding thevalve means open, time delay means operablejto release said releasable means after a given time interval, and means for restoring the Operating means after operation.

. 15. Adevice for refrigerating a package having an inner container and an outer container arranged around the inner container to leave a space between the container, the device com-- prising a receiver having an opening for receiving and positioning the package, discharge means V positioned to discharge carbon dioxide into said space when the package is positioned in the opening," and means controlling the discharge means.-

16. A device for refrigerating` packages' com prlslng a receiver having a chamber for receiving a package, the chamber being shaped to cooperate with the package to hold the same in a given position, discharge means for discharging.

carbon dioxide into the package when the package is -ln-the chambeu and a control for the discharge means.

17. A device tor reirigerating packages comprising a receiver having a chamber for receiving a package, the chamber being shaped `to cooperate with the package to' hold the same in a given position, discharge means for discharging carbon -dioxide into the package when the package is in the chamber, and a manually conditioned time governed control tor the discharge means operable to' cause the discharge` of carbon dioxide tor a given period.

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