US2732627A

US2732627A - Drying apparatus for alimentary paste of

Info

Publication number: US2732627A
Authority: US
Publication date: 1956-01-31
Anticipated expiration: 1973-01-31

Description

A. FAVA Jan. 31, 1956 DRYING APPARATUS FOR ALIMENTARY PASTE 0F FI-LAMENT SHAPE FilBd D80. 19, 1952 3 Sheets-Sheet 1 mo mh mm m mm 5 mvE/m Jan. 31, 1956 'A. FAVA 2,732,627

DRYING APPARATUS FOR ALIMENTARY PASTE 0F FILAMENT SHAPE Filld D60. 19, 1952 3 Sheets-Sheet 2 HUB N a R v 1: l N VEA/ TDR AILlfl/STD FA VA A NTS Jan. 31, 1956 A. FAVA 2,732,627

DRYING APPARATUS FOR ALIMENTARY PASTE 0F FILAMENT SHAPE Filed Dec. 19. 1952 3 Sheets-Sheet 3 lA/VENToR AUG-USTo F BY #memgivl United States Patent 3 Claims. (Cl. 34-48) The present invention relates to the drying of alimentary paste in the shape of filaments and in particular it relates to a new device for drying such alimentary paste filaments.

It is a main object of the invention to provide an apparatus capable of attaining perfectly uniform drying of the alimentary paste material including its inner layers, so as to prevent subsequent cracks and damages and hence to reduce considerably the consequent waste.

It is another object of the invention to perform the drying of the alimentary paste filaments in a drying chamber adapted for this purpose by passing the material alternately through zones of said chamber through which a flow of hot air is maintained and through other zones in which there is no direct action of a hot air stream, so that the moisture present in the interior of the alimentary paste material finds time, during the passage through the latter zones, to arrive at the surface so as to be then vaporized in the successive zone by action of the hot air stream.

Another object of the invention is to lead the hot air stream vertically through the drying chamber to contact successively a number of horizontal layers of alimentary paste filaments, there being heating elements arranged between successive superposed layers, in order to reheat the air for drying action on the paste material of each layer after the air has delivered part of its heat to the alimentary paste material of the layer therebelow.

A further object of this invention is to provide a simple control means for the heating elements including a single control member capable of regulating the drying effect of the apparatus to optimum value, excluding unfavourable influences and sources of error of the kind easily arising in the presence of individual regulating members for the individual groups, owing to the plurality of regulating possibilities.

-A further object of the invention is to provide within the drying plant a passageway for the already dried material prior to its leaving the plant, in which passageway the material finds time for cooling down and adapting to external temperature, so as to avoid any sudden tem perature drops.

Finally, it is an object of the invention to provide an apparatus that may be easily adapted in size to any existing. space conditions. The apparatus according to the invention is made up essentially of a drying chamber wherein there are provided transport means for conveying the carrier rods, which enter the chamber at one point and on which the paste filaments are hung, through the chamber along a plurality of horizontal superposed runs alternately in two opposite directions and subsequently to deliver them through a cooling channel at a discharge location of the apparatus.

According to the invention, the drying chamber has ventilating means associated therewith in such a manner that airisblown or passed vertically through the horizontal runs, the effective range of these ventilating means being confined to zones which are limited'in the direction of conveyance of the carrier rods for the paste filaments, so that zones exposed to the stream of air are alternately followed by zones having still air therein.

According to the invention, in the drying chamber there are also provided a plurality of heating elements. These heating elements are arranged in horizontal layers and extend crosswise with respect to the direction of conveyanceof said carrier rods for the paste filaments. A layer of such heating elements being arranged above each of the horizontal runs along which the carrier rods are conveyed but only in those zones that contain the ventilating means and which are exposed directly to the vertical air streams.

According to another feature of the invention, the zones 01' the drying chamber having the heating elements and the ventilating means, are surrounded externally by shafts which at their upper and lower ends are in direct communication with the inside of the chamber. Said ventilating means are arranged at said lower connections of the external shafts with the inner space of the drying chamber in such manner as to suck the air from inside the chamber and to blow it under pressure through said exexternal shafts towards the upper ends thereof, wherefrom this air returns again into the interior of the drying chamber through the upper connections with the external shafts. Hence in said zones the air sucked by the ventilating means streams through the drying chamber from top to bottom contacting the paste filaments passed in horizontal direction along the individual runs and is heated by the heating elements arranged in layers corresponding to the runs along which the paste filaments are conveyed.

According to the invention, at the lower ends of the ventilated zones of the drying chamber there are provided adjustable apertures for introducing fresh air and at the upper ends there' are provided adjustable apertures for discharging or exchausting moist air, there being provided members for regulating the air feed and dis charge, these members being coupled with one another in such a way that an equal quantity of fresh air is fed and an equal quantity of moist air is exhausted from the chamber.

According to a further feature of the invention there is provided a single source of heat, from which all of the heating elements are fed.

Moreover, according to the invention, there is provided a single member for regulating said source of heat, whereby all of said elements are controlled simultaneously.

These and other characteristics of the invention as well as their advantages are more fully described in the following description with reference to the accompanying drawings in which apparatus embodying the invention is illus: trated by way of example. The figures of the drawing show:

Fig. 1 is a longitudinal sectional view of the whole apparatus embodying the present invention;

Fig. 2 is a top view of the apparatus;

Fig. 3 is a section along line A-A of Fig. 2; and

Fig. 4 is a diagrammatical representation of the cycle of the medium used to heat the heating elements in the apparatus ofFigs. 1, 2 and 3. 1

In the drawings, the reference numeral 1 designates a casing which surrounds a drying chamber consisting of heated and aired or ventilated zones 2 and of non heated and still air zones 3, a shaft 4 for the introducing of carrier rods 6 hung with paste filaments 5 to be dried, as well as a channel 7 for cooling the dried paste material. In the interior of the casing 1 there is provided a conveying or transporting device for the carrier rods 6. This transportingdevice comprises an endless chain' 8 fat each of the two sides of the casing 1. The two chains 8 are guided over pinions identified by the reference numerals 9 to'23, inclusive. In Fig. 1' it is clearly seen that the pinions 9 to 23 are arranged so that the chains 8 of the transporting device follow parallel paths each of which comprises an initial section rising in the shaft 4 and successive sections running longitudinally to and fro in the

zones

2 and 3 of the drying chamber from the top to the bottom of the casing 1 to run finally through the cooling channel 7. A return channel 3i) is disposed below cooling channel 7 and opens into the bottom of shaft 4 to return the chains 8 to the latter. To the links of the chains 8 there are fixed at determined distances bolts 31 projecting in the direction from the lateral walls of the casing 1 towards the interior of the trying chamber and at the ends 32 of which there are pivoted pendular carriers 33. These pendular carriers 33 are adapted to grip the carrier rods 6 at their respective ends and to convey them following the movement of the chains 8, through the whole apparatus.

At any suitable place outside the casing 1 there is provided a drive motor 34 (Fig. 2), which through a drive shaft 35 to which it is connected by a belt and pulley transmission,

worms

38 and 39 fixed to the drive shaft and

worm gears

36 and 37 drives the pinions 9 and 23, thus imparting motion to the chains 8. Between the motor 34 and the transmission to the drive shaft 35 there is interposed a speed regulator 40.

For the feeding of the carrier rods 6 to the above described transporting or conveying device there is provided an endless transport device formed by two chains 41 (Fig. l) the chains 41 running around spockets 42 and and 43, with the sprockets 42 being driven from the motor 34.

The transmission of motion to the sprockets 42 is obtained from the drive shaft 44 which carries the pinions 9, by means of

pulleys

45 and 46 having a belt 47 trained there-around and fixed respectively on the shaft 44 and on a shaft 43 carrying the sprockets 42. A similar arrangement including chains 49 running over

sprockets

42a and 43a (Fig. l), is provided for the removal of the carrier rods from the carriers 33 after the latter have traversed the channel 7 and this arrangement is driven in substantially the same manner as that described in connection with the chains 41. Specifically, motion is transmitted from the shaft 44a carrying the pinions 23 by means of

pulleys

45a and 46a and belt 47a to the shaft 48a carrying the sprockets 42a.

The

chains

41 and 49 are provided with pushers 50, hich, when travelling over the upper runs of the chains catch the carrier rods.

in the zones 2 of the drying chamber there are arranged rows of heating elements in superposed layers which are respectively above the horizontal planes formed by the chains 8 and extend transversely with respect to the direction of conveyance of these chains. These heating elements are constituted by pipes 51 with disc-shaped ribs 52 arranged around the external surface of the pipes. The pipes 51 are fastened at their ends by means of supports 53 to the side there are provided horizontal connecting pipes 54 which connect the corresponding ends of the pipes 51 of the rows of heating elements with one another in each layer. Said connecting pipes 54 are in communication with one another by means of ascending

pipes

55 and 56, of which the pipe 55 serves for feeding and the pipe 56 serves for removal of the heating medium to and from the heating elements.

As shown diagrammatically in Fig. 4, the ascending

pipes

55 and 56 lead by way of

corresponding pipes

57 and 58 to a tank 59 serving as a storage vessel for the heating medium. in the outlet pipes 58 extending from the heating elements there is interposed a pump 60 by means of which the heating medium is kept in continuous circulation. V

In the tank 59 there is a heating element 61, which by suitable means, for example, hot water, or electrical resistors or gas or the like, brings the heating medium in the tank to the desired temperature.

In the illustrated embodiment, the heating is effected by walls of the casing 1. At both sides Y r and so on.

means of hot water in the coiled element 61, which from a source of any kind, not shown, is fed by way of the conduit 62 and is removed by way of the conduit 63. in the feed conduit 62 there is provided a regulating member 64, such as a slide valve or the like. This slide valve 64 provides according to the inventionthe single control member governing the temperature of the

heating elements

51, 52 and which can be actuated as required either automatically or by hand.

In the case of automatic adjustment of the slide valve 64, there may be provided, as diagrammatically indicated in Fig. 3, a control member 67 in one of the

shafts

65, 66 hereinafter described, which member 67 is set to a determined temperature value established to be favourable by experience, and guards continuously the temperature of the air stream passing through this shaft. In the case of temperature variations, control member 67 imparts in any suitable manner, e. g. electrically by means of the control conduit 24, a command to the slide valve 64 so as to adjust it as required to vary the heat feed to the tank 59 in such a manner that the temperature of the medium circulating in the

heating elements

51, 52, is varied accordingly. In this way the heating of the air stream circulated by fans 68 hereinafter described, is varied as required to obtain the value set with the control member 67.

In Fig. 3 it can be clearly seen that the zones 2 of the drying chamber are surrounded, outside their lateral confining surfaces, by

vertical shafts

65 and 66, which communicate at top and at bottom with the inside of these zones 2. At the locations where the

shafts

65 and 66 open into the bottom of the inner space, there are arranged fans 68, which suck air from the inner space as indicated by the arrows 69, and blow it upwardly through the

shafts

65 and 66 as indicated by the arrows 70. The air passed upwardly through

shafts

65 and 66 returns into the inner space through the connecting

apertures

71 and 72 at the top of the

shafts

65 and 66 and is here sucked downwardly through the zones 2, as indicated by the arrows 73, Fig. 3. In this way the air first flows around the

heating elements

51 and 52 of the upper row, and acts then upon the paste filaments conducted through the drying chamber in the top layer, to be then heated again by the next lower row of heating elements The bottom of the lowermost of the zones 2 of the drying chamber is formed by a perforated plate 74 below which there is a free space 75 serving to receive the fans 68 as well as feed conduits 76 (Fig. 1) for fresh air. These feed conduits 76 open into the spaces 75 through openings 77, which by means of the slide valves 78 can be controlled as to the side of the openings which they present for the admission of fresh air. Pipes 80 open into the top of the casing portions defining the zones 2 through openings 79 for discharging used, that is, moist air, the openings 79 also being controllable by means of slide valves 81. The upper and

lower slide valves

81 and 78 respectively are mechanically coupled in a manner not shown in the drawing, so that the openings 79 and the openings 77 always present passages for air of the same cross-sectional area.

The drying chamber as a whole, including

zones

2 and 3, is confined at the bottom by a horizontal i'mperforate plate 82, which at one end is spaced from the adjacent end wall of the chamber to define a passageway 83 (Fig. l) for the conveyor chains 3 with the loaded carrier rods 6. Below the plate 82 there is disposed the panel '7, which thus is not subjected to the action of the hot drying air and through which pass the carrier rods 6 with the already dried paste filaments 5, still conveyed by the chains 8, in order to cool down the paste goods and to adapt them to the external temperature. The 'sha'ft 7 is in communication with the external atmosphere by way of the exit opening 84.

Operation of the apparatus as follows:

hereinbefore described is From an apparatus (not shown in the drawing) for extruding, hanging and, cutting alimentary paste, situated before the drying plant according to the invention, the carrier rods 6 hung with the paste filaments 5 are conveyed by the conveyor chains 41 into the lower end of the shaft 4. Here one carrier rod after the other is seized at both sides by the pendular carriers 33 and moved upwards in the shaft 4 by means of the chains 8. Then each successive carrier rod 6 (which will now be followed in its way through the apparatus) is introduced into the interior of the drying chamber, to pass from left to right, as viewed in Fig. 1, along the upper run thereof. Here it passes first through a zone 3, which has still air therein and is not under the direct action of the hot air stream, and then through a zone 2, wherein the air stream, caused by the fans 68 and heated by the

heating elements

51, 52, flows in the direction of the arrows 73 and acts on the suspended paste filaments. By the action of this hot air stream, the paste material is slightly pre-dried. Inthe subsequentzone 3, into which the carrier rod 6 considered here is next conveyed, the paste material has time to allow the moisture accumulated inside it to get to the surface. Thus, a drying period follows alternately a rest period. After passing along the first conveyor run, the carrier rod 6 is brought into the second or next lower conveyor run and is conveyed in the opposite direction, that is, from right to left, as viewed in Fig. 1. Also in this next lower conveyor run a drying period follows alternately a rest period.

Therefore, the carrier rod 6 with the paste material filaments 5 hanging thereon moves along the successive superposed conveyor runs one after the other from top to bottom until it is finally guided by the chains 8, into the cooling channel 7. Here it is no longer subjected to the action of hot drying air, the paste material being already uniformly dried throughout and has time, during the passage through the channel 7, to cool down and to adapt its temperature to the external temperature.

When arrived at the exit 84, the carrier rod 6 is taken up by the transport chains 49, which carry it away for the further working of the dried paste filaments.

As already mentioned, the circulating air stream is reheated in the zones 2 of the drying chambers between the respective layers of drying material, in order to restore its effectiveness. It is clear that the number of

heating elements

51, 52 in the individual layers is different according to need, in order to provide the optimum conditions corresponding to the stage of dryness reached by the paste material. These optimum values once experienced and adapted to the existing conditions remain as they are without having to make or to fear any changes. The only critical factor is the temperature of the air stream in the

shafts

65 and 66, which is decisive for the drying of the material freshly introduced into the apparatus, because this air stream directly contacts the upper layer. The temperature of this air stream however is determined by the combined effect of all the

heating elements

51, 52 that it contacts in the zone 2 and it is for this reason that the regulating operation simultaneously controls all of the elements.

As a matter of fact, it has been found that the critical period for the paste material is that of first drying (that is in the upper layer). If in this period drying is pushed too far, it is no longer possible to reach equilibrium of moisture exchange between the inner and outer layers of the paste filaments, because the external layers form a hard shield which prevents release of the inner moisture. The consequence is that at the end of drying the material appears to be perfectly dried externally, while internally there is still accumulated moisture, which after a certain time produces cracks and damage of the material. This circumstance, however, cannot be recognized, or can be only in a very uncertain manner, after the complete drying. For this reason, according to the invention particular care is taken to ensure that the paste material attains determined favourable qualities in the first drying stage which are easily controlled even by non-specialized and non-experienced operators, so that the material leaves the drying apparatus at the end of the drying operation, in perfect condition.

The mentioned conditions are attained by means of the apparatus hereinbefore described and mainly by means of the particularly simple simultaneous and common regulation of all of the heating elements provided in the drying chamber at suitable places and in suitable number; and reduces drying waste to an absolute minimum.

What I claim is:

1. A drying apparatus for alimentary paste in filament shape, comprising a drying chamber, an inlet opening in the said chamber, conveying means for continuously introducing through the said inlet opening rods loaded with the dough filaments, other conveying means in the inside of the drying chamber for transporting the said rods along a plurality of superposed and successive horizontal runs which alternately move in opposite directions, a plurality of horizontally spaced rows of superposed heating elements, each heater of a row being disposed over a run of said conveying means, ventilating means above and below each row of heating elements, closed circuit means for heating medium and having said heating elements connected therein, a storage vessel for the heating medium and a pump for circulating the heating medium interposed in said circuit means, a single heat source in said storage vessel, control means sensitive to the temperature of the air circulated by said ventilating means, a single regulating means actuated by said control means and acting on said source of heat, an outlet channel for the rods loaded with dough filaments and separated from the drying chamber whereby the dough filaments passing through said channel are shielded from action of the heating and ventilating means, an outlet opening and conveying means for continuously discharging the rods charged with dried filaments.

2. A drying apparatus according to claim 1; wherein said ventilating means includes vertical shafts disposed outside those portions of the drying chamber which contain the rows of superposed heating elements and communicating with the interior of the drying chamber at the top and bottom thereof, fans disposed at the locations where said vertical shafts communicate with the bottom of the interior of said chamber to exhaust air from the latter and to blow the air upwardly through said vertical shafts, pipes for feeding fresh air opening into the bottom of said portions of the drying chamber, pipes for removing moist air opening out of the top of said portions of the drying chamber, and simultaneously acting slide valves for controlling the size of the openings of said pipes into and out of said portions of the drying chamber.

3. A drying apparatus according to claim 2; wherein said heating elements are formed by pipes extending laterally across said chamber; and wherein said closed circuit means includes a first manifold connecting the adjacent ends of the heating element pipes, at second manifold connecting the other ends of the heating element pipes, at first conduit extending from said storage vessel and connected in parallel to each of said first manifolds, and a second conduit having said pump interposed therein and extending from said second manifolds in parallel to said storage vessel to return the heating medium to the latter.

References Cited in the file of this patent UNITED STATES PATENTS Bettini Mar. 17, 1953