US2213206A - Coating apparatus - Google Patents

Description

Sept. 3, 1940. H p, CULVER 2,213,206

COATING APPARATUS Filed Aug. 24, 1938 3 Sheets-Sheet l o im I A; M 6% mm \\\\mm \\m\ Sept 3, 1940. H. P. cULvl-:R 2,213,206

GOATING APPARATUS Filed Aug. 24, 1958 4 3 Sheets-Sheet 2 NP RMK Sept 3, 1940- H. P. cULvl-:R

COATING APPARATUS Filed Aug. 24, 1958 3 Sheets-Sheet 5 l QA, MVM

Patented Sept. 3, 1940 UNITED STATES ooA'rnvG APPARATUS Howard Paul Culver, Detroit, Mich., assignor to The American Paper Bottle Company, Toledo, Ohio, a corporation of Ohio Application August 24, 1938, Serial No. 226,536

4 Claims. (Cl. 62-102) This invention relates to apparatus for,cool ing containers and like articles, and particularly to apparatus for rapidly cooling and solidifying coatings applied in molten condition to the Walls 5 of empty paper containers,

In application 172,025, filed October 30, 1937, in the names of Ira J. Shader and James E. Earp, tnere is disclosed a method of and apparatus for applying to all wall surfaces of an empty paper conta-incr a coating of a substance, such as paraiiin, in molten condition, which substance solidies or setsl upon cooling. In accordance with the method therein set forth an empty paper container, one end of which is closed, is immersed in l5 a bath of molten paraffin or parairin co-ntaining substance, or some other substance which is liquid when at elevated temperatures and which solidiL fles upon cooling to room or ordina-ry temperatures, the purpose being to provide the container with a smooth, homogeneous, liquid-repellent coating, which will eliminate the possibility of contact of any liquid subsequently introduced into the container with the -brous walls of the container.A The said apparatus embodies means for g5 subjecting different portions of the freshly coated container to the cooling action of different media, the upper portion, which is only one ply in thickness, and hence comparatively easily cooled, being subjected to the cooling action of a stream of air which has itself been previously reduced in temperature by refrigerating means, vand the lower portion or bot-tom of the container, which is several plies in thickness and also is more heavily coated, being subjected to the action of a body of liquid, for instance water, which liquid body is likewise maintained at a low temperature by cooling or refrigerating means.

'I'he cooling operation is carried out within a casing or housing having an aperture for the introduction of 'freshly coated containers and a second aperture for the discharge of such containers after 'the coatings have solidified and, in the operation of the mechanism, containers are introduced rapidly in succession through the inlet aperture and withdrawn at the same rate through the outlet aperture. In the case of the apparatus disclosed in the aforementioned application the means employed for effecting cooling of the circulated air stream and cooling of the body of liquid within the housing comprises a refrigerating mechanism primarily designed and intended for use with brine as a circulating refrigerant medum, the brine being cooled to the desired temperature by means located without the housing, circulated through the housing, and thence returned to the cooling apparatus for re-cooling or removal of the heat absorbed thereby during its passage through the housing.

In its general features the present invention is quite similar to that disclosed in the application 5 referred to and above brieily described. However, instead of the cooling mechanism provided by the prior invento-rs to effect the cooling of the air and liquid for the purposes specified, a speciallydesigned refrigerationapparatus of the com- 10 pression-expansion type is provided. Thus, in acccrdance with the present invention, a refrigeration apparatus is employed in which the refrigerant used may exist in gaseous o-r in liquid form, depending upon the temperatures and pressures 15 to which it is subjected. A 'refrigerating lappa-- ratus of this character necessarily includes a compressor, a condenser, a closed circuit which includes the compressor, the condenser, the work circuit or cooling coil, and various control instrugo mentalities. In general refrigerating apparatus of this type is o-ld and well-known and no broad claim of novelty is made therefor. However, in adapting this type of refrigerating mechanism specifically to the cooling of freshly coated con- 25 tainers or like objects, numerous changes have been made which greatly facilitate the operation of the apparatus in lthe performance of its intended functions. These novel features will be hereinafter specifically pointed out and claimed. 30

One embodiment of the invention is illustrated in the accompanying drawings but it will be appreciated by those skilled in the art that this is set forth by way of example only and that, Within the importof the invention, numerous minor w changes in the design and arrangement of its component elements may be effected.

In the drawings:

Figure 1 is a longitudinal vertical section taken through the lower portion of the housing for the o container cooling mechanism, showing certain elements of the refrigerating apparatus employed;

Figure 2 is a horizontal section through the housing taken o-n the line 2-2 of Figure 1;

Figures 3 and 4 are transverse sections through the housing, taken respectively on lines 3-3 and 4-4 of Figure 2; Y

Figure is a section on line 5 5 of Figure 2, theparts shown, however, being illustrated upon 50 a somewhat larger scale; and

Figure 6 is a side elevation of the refrigerating apparatus employed, portion of this apparatus being diagrammatically illustrated and the housing being omitted. 55

The means for circulating a gaseous stream, for instance a stream of air, through the housing, cooling it at one point, and passing it over the coated containers at another point, comprises no portion of the present invention in and of itself, being fully disclosed in the prior application above mentioned. Likewise the broad concept of subjecting the bases of the containers to the action of a liquid comprises no portion of the present invention. For a full and complete description of the air circulating means reference may be had to the application previously referred to, and a brief description only of the housing and air circulating means need here be given.

As readily perceived from an inspection of Figures 1 to 4, inclusive, the housing comprises an elongated box-like body portion I0 and a top I'I which preferably is readily removable to permit access to the interior of the housing. At the ends of the housing, and formed partly in the body I0 and partly in the top I I, are aligned rectangular apertures, one of which is indicated at I2 in Figures 3 and 4, for the introduction of containers which have been freshly coated and the discharge of completely cooled containers, respectively. A series of containers passing through the housing is indicated in Figures 1 and 2, these containers being moved in the direc.- tion of the arrow A (Figure 1) by conveyor means which is not illustrated. The entering containers, indicated at C, are shown to be resting upon a heated trackway I3 and the containers indicated at C are shown with their lower ends immersed in a body of liquid which is artificially cooled. During the time that each container is passing through the housing practically all portions of the walls thereof, both exterior and interior surfaces, are subjected to the action of a cool stream of air the effect of which is to solidify or harden the molten paran or other molten coating substance which has been applied thereto just prior to introduction of the container into the cooling chamber. A fan for the circulation of this stream of air is indicated at I4, this fan causing air to circulate in a closed circuit, in the direction indicated by the small arrows in Figure 4. The details of the air circulating means need not be here described, and it is only necessary to say that the air delivered by the fan passes upwardly on the right-hand side of the longitudinally extending substantially vertical division plate I5, thence transversely and downwardly, as directed by the inclined vanes I6 and the undersurface of the cover II, so as to sweep over the surfaces of the line of containers C and C', and to some extent into the interiors of these containers, thence downwardly on the left-hand side of the central partition I5 to the intake ports of the fan.

As this air stream passes upwardly toward the containers, and again as it passes downwardly from the containers to the fan, it passes through banks of finned tubes, indicated at I1, so that the air stream is cooled both as it approaches the containers and as it leaves the containers. The bottoms of the containers C' are immersed in a body of water indicated at I8, this water being contained in a longitudinally extending horizontally disposed pan I9. Extending through the pan in a longitudinal direction are a plurality 0f tubular ducts 2U through which is passed a refrigerant, this nest of tubes 2U comprising portion of the cooling system to be hereinafter more fully described. In the operation of the apparatus the body of water I8 is maintained at a temperature slightly above freezing, in order that this body may exert the maximum cooling effect upon the bottoms ofthe containers.

In Figure 6 of the drawings the mechanism for cooling the circulating air and cooling the water in the pan I9 is most clearly illustrated. This cooling system is of the compression-expansion type, embodying a compressor diagrammatically indicated at 25, a condenser diagrammatically indicated at 26, and a closed circuit which includes both compressor and condenser, as well as the work performing conduits or pipes, and the various control instrumentalities commonly used in association with such circuits. The refrigerant used may for example be ammonia, which exists as a gas at certain temperatures and pressures, and as a liquid at lower temperatures and higher pressures. The refrigerant passes through this circuit in the direction of the arrows shownI being forced by the compressor 25 into the condenser 26 and issuing from the condenser into receiving tank 2B', from which tank it passes into conduit 21 and then downwardlyv through this conduit to the horizontally disposed chamber 28 which is so designed, and is so positioned in the system, that it accommodates the refrigerant in both its liquid and gaseous forms.

The refrigerant in liquid form will pass into conduit 21 under relatively high pressure, for instance a pressure of approximately 165 pounds per square inch. At the discharge end o1" this conduit, however, there is positioned valve means for controlling the flow of liquid refrigerant to the chamber 28, this control means being diagrammatically shown in Figure 6. Thus a float controlled valve is indicated at 29 and a float operatively connected thereto is indicated at 30.

This oat controlled valve may be of any desired construction and it functions to maintain the level of the liquid refrigerant within the chamber 28 at approximately that which is indicated in Figure 6 by the dotted line 3|. When the liquid level falls, the float 30 descends and the valve device 29 opens to permit the inflow of liquid refrigerant, but when the liquid level 3l is restored, the valve device 29 is closed in the usual manner to prevent further inow.

From the bottom of the chamber 29 there projects downwardly a tube or conduit 32 which is in communication with a header 33 extending transversely of the housing I0. Communicating with the header 33 are the inlet ends of the transversely extending series of tubes or conduits I1 which pass forwardly and rearwardly in a serpentine manner and have their discharge ends in communication with a header 35 upon which is mounted spaced blocks 35 having flat horizontal upper faces. Each horizontal reach of each tube 35 is slightly inclined to the horizontal so that gas bubbles, which may form for instance in the lowest reach, may work their way upwardly to the header 36. Communicating with the header 36 is a relatively short second header 31 upon which are mounted spaced blocks 38, the vertical passages indicated at 39 (Figure 5) formed in these blocks serving to bring into communication the parallel headers 35 and 31. The blocks 38 are rigidly secured to the blocks 36 by bolts or screws, the heads of two of which are indicated at 40 in Figure 5.

Communicating with the duct 31 and header 38 are the plurality of tubes 20' which pass through the water pan I9 adjacent the bottom thereof, these tubes being disposed in close relationship and extending horizontally from the header 38 to the header 4|, into which all of the tubes 20 discharge. One end of header 4| is extended laterally and terminates in a longitudinally extending portion 4|' which is connected to chamber 28 by detachable coupling 42, the point of discharge of the refrigerant. passing from the header 4I .into the chamber 28 being located above the level of the liquid 3| in that chamber.

Rising from chamber 28 is an uptake 43 of relatively large diameter which constitutes a portion of the conduit for leading gaseous refrigerant to the intake side of 'the compressor 25, the uptake 43 being of relatively large diameter in order that it may comprise, in effect, a separating chamber lor gas and liquid. In the gaseous refrigerant return line, beyond the uptake 43, is a pressure regulator 44 and this regulator is so adjusted that the pressure of the gaseous refrigerant in uptake 43 and in chamber `28 will approximate, where ammonia is employed as a refrigerant, 50 pounds per square inch, which pressure will ensure maintenance of the desired temperatures in the various parts of the Work circuit. The pressure indicators and cut-oil valves 'lustrated in the drawing are of conventional form and need not be described in detail, the pressure indicator being indicated at 45 and cutcfl valves at 46 and 41.

Water is supplied to the pan I9 through a water pipe or duct'li, having an adjustable metering valve 48; from a suitable source of supply, this water passing through a chamber 49 which encircles the refrigerant uptake 43 and being cooled while in said chamber to a low temperature. It will .be appreciated that each container passing through the water in the pan I9 will, whenremoved, carry some small drops of water with'it, hence the necessity for maintaining an inflow. The inflow of water will likewise cause the pan to quickly ll in the event that all containers are removed therefrom, at the termination of a run, and hence insure that a satisfactory'body of water is in the pan at the beginning of a further run. Any excess water flowing into the pan will escape from its lefthand end (Figure 1) and will fall onto the return flow trough I9 and thus be conducted from the housing.

Extending downwardh7 from the header 33 is a downtake 50 and communicating with the bottom of this downtake is a horizontally extending drain pipe 5I having a discharge orifice 52 controlled by a valve 53. By opening the valve from time to time oil which collects in the sump or downtake 50 can be removed, s-uch oil being introduced into the 'refrigerant by the compressor and, being heavier than the refrigerant, settling to the lowest point in the system.

It will be observed that thel pan I 9 and the series of horizontally extending pipes 20, together with the headers 31 and 4|, lie above the level 3| of the liquid within the chamber 28.

Ordinarily therefore liquid refrigerant will not rise from the header 35 into the header 31 and hence will not fill the pipes or ducts 20. In the operation of the apparatus, however, small bodies of liquid refrigerant are entrained by the gases which are generated in the various ducts I1 for the liquid refrigerant, these bodies passing upwardly from the header 35 to the header 31, together with the rising gas, and being conducted through the tubes. 2U to the header 4| and thence back to the gas and liquid chamber 28. The effect of the refrigerant passing through tubes 20 is to maintain the temperature of the water body-in the pan I9 at approximately33 F., or just above freezing. so that the cooling effect of the liquid on the container bottoms is as great as possible. The ends of pan I 9 are attached to the headers 31 and 4I, respectively, and as these headers are detachably connected to the headers 35 and the chamber 28, respectively, it follows that the pan I9 'and the associated tubes 2and headers 31 and 4I4 comprise a unit which may be readily removed from the apparatus for cleaning and repair, a very desirable feature of such an apparatus.

The refrigerant circulatory system described is provided with several features which safeguard it and prevent damageunder unusual conditions. Thus it may happen that automatic control valve 44 fails while the machine is in operation. In order to prevent loss of bottles or containers upon such an occurrence a by-pass around the valve 44 is provided, which by-passl is ,equipped with a manually operable needle valve 6I. When automatic valve 44 fails valve 6I may be opened and manually adjusted to maintain the desired temperatures until such time'as the machine can be stopped and valve 44 repaired.. A conduit controlled by a needle valve 60 isprovided to permit the introduction of refrigerant into chamber 28 in the event that valve 29 fails to open. This valve may likewise be manually controlled to regulate the temperature in the cooling system until such time as valve 29 can be repaired.

A second by-passaround valve 44 is provided,

' the pressure in which is controlled by a safety lvalve 62. This valve will open when, due to failure of automatcvalve 44, an excessive pressure builds up in the uptake 43. The system is also provided with a trap 63 in which scale and other solids' may collect and from which such substances may, from time to time, be removed.

In the event that it is desired to remove the refrigerant from the machine this can easily be accomplished by closing valve 41 and operating the compressor, whereupon the gas is gradually withdrawn from the cooling coils, condensed and stored. This processI can be expedited, if desired, by heating the cooling coils, for instance with steam or hot water.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. The combination with a container cooling mechanism of the type including a casing having means therein for circulating a stream of air over the walls of a container passing therethrough, a body of liquid in which containers may be successively partially immersed and a conduit for a refrigerant having a portion disposed in the path of the stream of air and a second portion, in series with the first portion, disposed in heat exchanging relationship with said body of liquid, of a chamber for a refrigerant to which the ends of said conduit are connected, means for maintaining within said chamber a body of liquid refrigerant of predetermined depth, and means for withdrawing gaseous refrigerant from the upper portion of said chamber, the arrangement being such that liquid refrigerant passes from the chamber into one end of said conduit and gaseous refrigerant passes from said conduit -into the chamber.

2. The combination with ,a container cooling mechanism of the type including a casing having means therein for circulating a stream of air over the walls of a container passing therethrough, a body of liquid in which containers may be successively partially immersed and a conduit for a refrigerant having a portion disposed in the path of the stream of air and a second portion, in series with the first portion, disposed in heat exchanging relationship with said body of liquid, of a chamber for a refrigerant to which the ends of said conduit are connected, means for maintaining within said chamber a body of liquid refrigerant of predetermined depth, and means for withdrawing gaseous refrigerant from the upper portion of said chamber, the arrangement being such that that portion of the conduit which is disposed in heat exchanging relationship to the body of liquid normally contains gaseous refrigerant and that portion over which the cooling air passes normally contains liquid refrigerant.

3. The combination with a container cooling mechanism of the type including a casing having means therein for 'circulating a stream of air over the Walls of a container passing therethrough, a body of liquid in which containers may be successively partially immersed and a conduit for a refrigerant having a portion disposed in the path of the stream of air and a second portion, in series with the rst portion, disposed in heat exchanging relationship with said body of liquid, of a chamber for a refrigerant to which the ends of said conduit are connected, means for maintaining Within said chamber a body of liquid refrigerant of predetermined depth, and means for withdrawing gaseous refrigerant from the upper portion of said chamber, the arrangement being such that that portion of the conduit which is disposed in heat exchanging relationship to the body of liquid is of less crosssectional area than that portion over which the cooling air passes, for the purpose set forth.

4. The combination with a container cooling mechanism of the type including a casing having means therein for circulating a stream of air over the walls of a container passing therethrough, a body of liquid in which containers may be successively partially immersed and a conduit for a refrigerant having a portion disposed in the path of the stream of air and a second portion, in series with the first portion, disposed in heat exchanging relationship with said body of liquid, of a chamber for a refrigerant to which the ends of said conduit are connected, means for maintaining within said chamber a body of liquid refrigerant of predetermined depth, and means for withdrawing gaseous refrigerant from the upper portion of said chamber, the arrangement being such that portion of the conduit which is disposed in heat exchanging relationship t the body of liquid has its ends connected to headers, one such header being detachably connected to the discharge end of the other portion of the conduit and the second header to the said chamber.

HOWARD PAUL CULVER.

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