US2474952A

US2474952A - Apparatus for heating and drying granular material in a continuously flowing stream

Info

Publication number: US2474952A
Application number: US556533A
Authority: US
Inventors: William J Miskella
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-09-30
Filing date: 1944-09-30
Publication date: 1949-07-05
Anticipated expiration: 1966-07-05

Description

ly 5, 1949- w. J. MISKELLA 2,474,952

APPARATUS FOR HEATING AND DRYING GRANULAR MATERIAL IN A CONTINUOUSLY FLOWING STREAM Filed Sept. 30, 1944 4 Sheets-She et 1 ly 5, 1949. w. J. MISKELLA 2,474,952

APPARATUS FOR HEATING AND DRYING GRANULAR MATERIAL IN A CONTINUOUSLY FLOWING STREAM Filed Sept. 30, 1944 4 Sheets-Sheet 2 y 5, 1949. w. J. MISKELLA APPARATUS FOR HEATING AND DRYING G MATERIAL IN A CONTINUOUSLY FLOWING STREAM Filed Sept. so, 1944 RANULAR 4 Sheets-Sheet 4 w yzsM Patented July 5, 1949 UNITED STATES PATENT OFFICE APPARATUS FOR HEATING AND DRYING GRANULAR MATERIAL m A ooNTmU- OUSLY FLOWING STREAM William J. Miskella, Cleveland, Ohio Application September 30, 1944, Serial No. 556,533

7 Claims. 1

My invention relates to heating and drying apparatus, and, in particular, to a novel oven for heating and drying granular material such, for example, as powdered plastic.

In the manufacture of articles from synthetic materials, such as those commonly called plastics, one of the difiiculties to surmount is the removal of the excess moisture in the raw material. However, the presence of this moisture is not readily detectable from a physical examination of the plastic powder, and chemical tests I frequently must be made, which take time and add to the manufacturing costs. At the present time it is the custom to detect the presence of moisture by forming an article from the raw material and then subjecting it to inspection and tests to detect physical flaws caused by undesirable moisture. When moisture is found the material is dried before being used for further manufacturing operations. This empirical approach to the problem of moisture removal has its very obvious drawbacks.

Should a piece be finished from a raw material containingv an excess amount of moisture, its surface is very apt to possess flaws, or there may be hidden structural weaknesses which will permit the article to fracture while in use. If this moisture is removed prior to the forming operation, these flaws and defects can be substantially eliminated, thereby materially reducing the cost 2 cylinders withlarger or an increased number of mold cavities.

The practical application of infra-red radiated heat for the removal of moisture from powdered plastic and for preheating the material prior to the extrusion or molding operations was not possible prior to my invention. With my heating and drying oven it is commercially feasible to dry the powdered material for the purpose of removing the excess moisture. During the drying the material is heated, and, if used immediately, some savings are gained in the forming operation. My invention, therefore, makes possible the use of infra-red heat in a practical commercial drying oven for the inexpensive and efiicient tinuous flowing stream.

of manufacturing the plastic article by reducing the number of rejections at the inspection line.

Some of the raw plastic materials, such as the acetates, are hygroscopic on cooling after drying under certain climatic conditions. Therefore, it

is essential that the forming operation be comthe plastic before the start of the forming opera- I tion, or that some means be provided for feeding the heated raw material directly to the machine which performs the forming operation. v

For molding processes, the raw plastic material a must be heated prior to the time that it isplaced in the feed cylinder ofthe injection molding machine. When the plastic is preheated before being fed to the machine, it permits a reduction in the molding pressure and gives a more even and efficient operation. Moreover, when my novel heating and drying oven is used directly with a 55 parent from the following description taken in molding machine, it is possible to use larger feed Another object is to provide an apparatus in which the rate of supplying the granular material can be carefully regulated.

Another object is to provide an apparatus in which the temperature can be regulated to give the desired amount of heat.

Another object is to provide an apparatus which is self-cleaning in the event that it is desired to change the material being treated.

Another object is to provide a machine inwhich the change from the treatment of one raw material to the treatment of another is readily accomplished.

Another object is to provide an apparatus which may be used directly with various types of plastic forming machines.

Another object is to provide an apparatus in which theevaporated moisture and volatile substances are removed from the material being treated in such a way that they do not .cake

the apparatus.

the treatment of a continuous stream of flowing material which has a minimum of moving parts. Another object is to provide an apparatus wherein the controls may be located at a point remote from the apparatus.

Another object is to provide an apparatus whichhas a rugged construction and yet which is economical to manufacture.

Other objects and advantages will become ap- Another object is to provide an apparatus for conjunction with the accompanying drawings, in which,

Fig. 1 is a side elevational view of the heatin and drying apparatus of my invention mounted for use with a standard type injection molding machine;

Fig. 2 is a longitudinal cross-sectional view taken somewhat in front of the center line of the heating and drying apparatus with some parts being shown in elevation and illustrating a modified means for receiving the heated and dried material;

Fig. 3 is an end elevational view of the apparatus as viewed from the left in Fig. 2.

Fig. 4 is a cross-sectional view taken substantially on the line 4-4 of Fig. 2;

Fig. 5 is a horizontal sectional view and may be considered as being taken substantially on the line 5-5 of Fig. 2;

Fig. 6 is a detailed sectional view of the resilient mounting for the vibrating tray;

Fig. 7 is a fractional side elevational view showing the details of the hopper adjustment;

Fig. 8 is a wiring diagram illustrating the manner of connecting the apparatus to a 220 v. source of electrical power; and

Fig. 9 is a wiring diagram illustrating the manner of connecting the apparatus to a 110 v. source of electrical power.

In the drawings I have shown a preferred embodiment of my invention, andin Fig. 1 the heating and drying apparatus indicated generally by the numeral I8 is shown applied to a standard injection molding machine 12 which is of the type manufactured by the Reed-Prentice Corp,

= of .Worcester, Massachusetts. In general, the

heating and drying apparatus comprises a feed hopper I4, an oven section l8, and a vibrating tray l8 which is passed completely through the oven section, and which is fed from the hopper l4 and empties its contents of treated material into a hopper 28 on the molding machine (Fig. 1) or into trays 22 (Fig. 2).

The operating portions of the apparatus are supported by a frame 24 having a pair of

end elements

26 and 28. The element 28 is formed of a pair of uprights 30 of general channel section with the legs of the channel facing outwardly, and connected by

cross members

32, 34 and 36. The upright endelement 28 is likewise composed of a pair of vertically disposed channels 38 connected by

cross channels

48, 42 and 44. The

end frame elements

26 and 28 are connected longitudinally by

channels

48 and 48. The frame members may be welded at their junctions, and this construction is preferred because it eliminates the use of overlapping flanges and connecting angles. which would be necessary in the event that the frame were of bolted or riveted construction.

The oven section l8 occupies the upper portion of the apparatus, and the heat used in the oven is obtained from a bank 58- of infra-red lamps 52. Each of the lamps 52 is supported by a socket 54 which is secured to a shallow wideweb sheet metal channel 55, which is welded to a deeper sheet metal channel 58 having turned in edges 68 forming flanges at the outer ends of the leg members of the channel (see Fig. 4). I

An insulated reflective panel 82 is separated from the channel 58 by a number of bolts and wing nuts 84 confining a spring between the reflective panel 82 and the flange 80. By the use of this nut, bolt, and spring assembly the position of the insulated reflective panel 82 relative panel. This panel comprises a sheet metal face 55, coated with a reflective material, and a back plate 88. The

plates

88 and 88 have their edges turned toward each other, and these flanges are welded to a welding strip I0. To receive the enlarged portions of the infra-red lamps 52 there are appropriately spaced openings in the panel which are fitted with reflective frusto-conical shaped ringsv 12 having flanges to secure them to the

plates

88 and 88. The space between the

plates

88 and 88 is fllled with suitable insulating material 14.

The deep sheet metal channel 58 which supports the bank of lamps and the reflective panel is itself supported by the frame 24. Near each corner of the channel 58 there is positioned a long bolt 18 which is passed through a suitable hole in channel member 48. At its upper end the bolt is threaded and is provided with a nut 18 and washer 88. and a spring 82 is confined between the channel 48 and the washer 80. The proper height for the bank of lamps within the oven section l8 may be regulated by adjusting the nut 18. As the bolt I8 has its head 84 preferably welded to the channel members 56 and 58, the spring 82 confined between the channel 48 and the washer 88 gives the bank of lamps and the reflective panel a floating and shock absorbing support so that any vibrations in the apparatus will not be transmitted to the lamps to insure that they will not be damaged.

As seen most clearly in Fig. 2, the tray I8 is positioned directly below the lamp bank 50, and

comprises a heavy bottom plate 88 which has the surface faced toward the lamps 52 absolutely smooth and preferably plated with a reflective substance such as chromium or cadmium. The tray I8 is slanted down toward the outlet end at the right, and a pair of side plates 88 are bolted thereto by bolts 98. The side plates likewise are perfectly smooth, so that the tray will present no obstruction to the free flow of granular material throughout its entire length. At the inlet end an end plate 92 is secured to the side plates 88 by a pair of wings. 94 which may be welded or bolted to the plates 88. The lower edge of the end plate 92 is formed with a flange 98 which rests firmly on the upper surface of the plate 88.

- The plate 88 is made of a very heavy section so that it will absorb heat from the lamps 52 and then transfer this stored heat to the granular material as it passes through the apparatus while the machine is operating. Thus, the granular material is heated by the direct and reflected rays from the lamps 52 and by contact heat transfer from the plate 88. The plate 88, therefore, is a heat storage means for insuring that the lower layer of the granular material will be properly heated and dried.

The tray I8 is vibrated forwardly and rearwardly in the direction of the flow of material,

by a standard type of magnetic vibrator or pulsator 88. The one illustrated is model V-9 manufactured by the Syntron Company of Homer City, Pennsylvania. The tray is mounted on suction cups I88, I82 disposed near its inlet and outlet ends. andis vibrated 'on these mountings; the suction cups I88 are secured to the channel 34 and the suction cups I82 are secured to the channel 42. As seen most clearly in Fig. 6, each suction cup is provided with a bolt I04 which is molded in a boss I06 formed at the upper end of the cup. The bolt I04 is threaded into a ward and rearward vibratory motion tothe tray I8, it is mounted upon a pair of triangular plates H0. The plates IIO are bolted to the underside of theplate 86 by flanges II2 and bolts H4; flanges H6 are formed on another edge of the plates H and are welded or bolted to a plate II 8 to which the vibrator 88 is fastened by bolts I20. By positioning the vibrator 98 more closely to an upright position, the efiect of the pulsating element in the vibrator maybe used to carry the tray I8 very slightly forwardly and also very slightly rearwardly in a direction parallel to the flow of the granular material.

As the granular material is passed through the tray I8 and is subjected to infra-red radiated heat from the lamps 52 and to the heat which is stored in the plate 88, its temperature is raised and it loses the undesirable excess moisture and also a small amount of volatile substances. These evaporated substances carry with them from the powdered plastic a small amount of very fine plastic dust; this is particularly true when ground up and re-used plastic is being treated. In order to prevent the gumming or caking of the reflective surface of the'panel 62 and the faces of the lamps 52, I have found it desirable to pass a stream of air through the oven space between the panel 62 and the vibrating tray I8. For this purpose I use a small blower I22 which is secured to a'plate I26 closing the outlet end of the machine, leaving an opening I26 for the passage of the outlet end' of the vibrating tray I8 and the granular material. It is not necessary to drive. the air through the space between the tray and the panels in any great volume, and it is sufficient if there be a slow, continuous circulation of air through the oven space. It will be noted that this space becomes gradually more confined toward the inlet end of the machine where there is positioned a chimney I28 to exhaust'the contaminated air. This arrangement provides for a slight increase in the speed ,of the air flow at this point and also for sumcient turbulence of the air at the right end of the apparatus (Fig. 2) so as to clear out those spaces which are immediately adjacent the blower outlet.

The chimney I28 is formed of a pair of sheet metal members I30 and I32 (Figs. 2 and 5). The sheet I32 extend-s between and is held against the outer or rear flanges of the upright channels 30 and its lower edge I33 is at approximately the level of the panel 62 so as to form with the tray I8 and the webs of the channels 30 a large opening facing the space between the lamp bank and the tray I8. The plate I30 is bent as shown in Fig. 5; it has a wide central portion I34 which forms the back wall of the chimney and is bent forwardly at I36 to provide the side walls thereof. Flanges I38=are bent outwardlyfrom the side walls, and bolts I40 secure the plates I30 and I32 to the channels 30. Below the lower edge I33 of the plate I32 there are spacer strips I42 of the same thickness as the plate I32 which prevent the lateral escape of contaminated air and to compensate for the fact that the plate I32 is cut off at I33. It is advisable to exhaust the chimney I28 directly into a conventional laboratory type chimney I44 so as to prevent the passing of the contaminated air into the room in which this apparatus is being used.

The hopper I4 is formed of an upper section I46 and a lower section I48, and is preferably made of sheet metal construction throughout. Intermediate the two sections there is provided a gate I50 to shut off the flow of material from the hopper when desired, and to prevent the flow of material from the hopper while it is being secured on the apparatus. the lower section IE8. is slightly larger than the lower end of the upper section I06, so that there will be no spilling of the granular material while the gate I50 is in openposition (Fig. '1). A window i 52 is provided in the upper section H6 so that the operator can observe when the sup ply of material in the hopper is running low and can gauge the operation of this apparatus and A the molding machine to which it might be attached.

The hopper is removable, and its vertical position is adjustable so that the flow of material therefrom can be regulated with extreme accuracy. Near the upper end of the chimney there -is provided a pair of studs I58 at either side of the chimney I28, and at the upper forward edge of the hopper section I46 a pair of plates I56 are welded to the side walls of the hopper, each plate having a bayonet slot I58 cut therein to engage the studs I54.

As seen most clearly in Fig. 3, the lower edge of the section I06 of the hopper is turned'outwardly at I60, and'the upper edge of the hopper section is turned outwardly at'I62. A strip I64 the thickness of the gate is confined between the outer edges of the flanges I and I62, and this assembly is covered by a deep chanel shaped strip I66 and is secured by bolts I68. The strip I66 and its enclosed flanges extend beyond the front edge of the hopper a distance slightly shorter than the width of the side walls I36 of the chimney I28.

At its lower edge the chimney I28 is provided with a pair of angles I10 which have their lower flanges I12 directed outwardly and their up wardly directed flanges I14 welded to. the inner I face of the side walls I36 of the chimney. The

flange I12 is provided with anopening through which is passed an adjustment bolt I16. A pair of nuts I18, I80, disposed oneither side of. the flange I12, lock the bolt I16 in the adjusted position,

When the hopper I4 is positioned on the ma- ,chine the studs I54 are slipped into the bayonet I -slot I58 in the plate I56 and the hopper is dropped downwardly until the channel I66 engages the upper end of the adjustment screw' I16. This positions the opening I82 a. predetermined distance above the upper face of the plate 86. So

that the vertical adjustment may be made without trial and error, a scale I84 may be etched in the sidewalls I36 of thechimney. The front wall of the hopper rests against the wall I34 of the chimney and prevents rotational movement of the hopper; furthermore, these walls act as a heat exchange medium between the exhaust air and the granular material in the hopper.

Each side of the apparatus ,is enclosed by a pair of removable'gates'l86 and I88 sliding in The upper end of slots I80 which are formed by a flange I82 on the

channels

30 and 88 and the angle I84 welded to each of the channels 30 and 38. The gates I86 and I88 join on a line which is substantially parallel and at the height of the vibrating tray I8. During the normal use of themachine it would be unnecessary to remove the gate I86. but it is usually desirable to have the gate I88 readily removable so that a quick inspection of the tray I8 may be made whenever it is desired to change the hopper from treating one plastic to the treatment of another so that the operator can be certain that tlie tray I8 is perfectly clean.

It has been stated that it is feasible, and very often desirable, to use this apparatus directly with injection molding or other forming machines, in which case the apparatus would be mounted so that the vibrating tray I8 would feed directly into the hopper of the forming machine. However, when this is not desirable. or due to some characteristic of the forming machine is not possible, I prefer to feed the plastic into trays or pans 22. In Fig. 2 I have shown a means for supporting these trays at the outlet end of the machine, which comprises a sheet metal housing I88 provided with a pair of rails 200 for supporting a tray. A second tray 22 fits readily below the rails 200 into the lower portion of the housing.

It might also be desirable to make this apparatus movable and to that end it may be mounted on a wheeled table, the upper portion of which is shown in Fig. 2. The frame 24 is bolted directly to the table top 20-2, which in some instances may be secured directly to the legs 204, 206. However, for reasons which will become apparent irmnediately hereinafter. I prefer to make the machine tiltable to a very slight degree, and at the front edge a hinge 208 connects the table top 202 and the front legs 206. At the rear of the machine a pair of angles 2I0 are bolted to the legs 204 and are adapted to be engaged by an adjustment screw 2I 2 which is threaded through a boss 2 formed on an angle 2I6 which is in turn bolted or otherwise suitably secured to the channels 30. By adjusting the thumb screws 2I2 I can raise or lower the inlet end of the machine, thereby placing the vibrating tray I8 at a definite angle relative to the hori-- zontal. This adjustment is found to be important because at times it is necessary to shut off the machine and stop the vibrator 88. When this occurs there should be no flow of granular material from the tray I8 into the trays 22 or into the molding machine hopper. Should the angle be too steep for a particular material, the natural forces acting on it will cause at least a. slight flow, regardless of the fact that the tray I8 is not being vibrated. Therefore, the angle to which the tray I8 should be adjusted is one at which the material being processed will not move when the tray is at rest, but which is sufficient to allow material to flow from the tray just as soon as the vibrator 98 is operated. In general, however, I have found that a grade of about 1 to 9 is practical for the treatment of most types of plastic material. and when the tray I 8 has been placed in this position further adjustment is usually unnecessary.

This apparatus is completely electric in its operation and two wiring diagrams for the apparatus are clearly shown in Figs. 8 and 9. In Fig. 8 I have shown a typical wiring circuit illusto the lamps from a 220 volt source. and for supplying current to the vibrator 88 and to the blower I22 from a volt source. The 220 volt source of electric current is indicated by the reference numeral 220. and that line is controlled by a single-throw double-pole switch 222 connected to the inlet side of a variable current controller 224. One connector 226 leads from the outlet side of the controller 224 to four pairs of lamps 52, each pair being arranged in series, as the customary heating lamp is one which utilizes a current of only 110 volts. Connected in series with each pair of lamps 52 is a switch 228 by which any definite number of pairs of lamps can be ener-.

gized at a given time.

By closing any number of the switches 228, the number of lamps which are to be used is selectively determined, and by adjusting the control on the controller 224 the amount of current supplied to the lamps in use may be regulated. It has been found in actual practice that the determination of the amount of current to obtain a particular amount of heat through a given number of lamps is empirical, and, consequently, a small amount of trial will be necessary before the optimum operating conditions are obtained. After these conditions have been determined, control dial 260 on the controller 224 may be set to reproduce them as desired.

The source of 110 volt current is indicated generally by the reference numeral 230, and a pair of conductors 232 lead directly to the control box 234 for the vibrator 88. The control box 234 is provided with an oif-and-on switch 236 and a speed adjustment control knob 238 which may be manipulated to adjust the intensity of the vibrations given by the vibrator 98. A switch 240 is positioned in series with the blower I22 and its motor, and this circuit also includes a pilot or indicating light of small wattage 242. It has been found in practice that it is desirable to segregate the control switches 222, 236 and 240 for the lamps, vibrator and blower, respectively, but it is, of course, feasible to include in this circuit a master control switch and such a switch may be added to the circuits by any person skilled in the art.

The only difierence between the circuit in Fig. 9 and that in Fig. 8 is that the current supplied to the lamps 52 is from a 110 volt source indicated by the reference numeral 250. One outlet connection v252 from the controller 224 leads to one side of four pairs of lamps, the lamps in each pair being connected in parallel. and the four pairs being connected in parallel. Each pair of lamps is controlled by theswitch 254 which is in series with the conductor 252 and the pair of lamps 52. The remainder of this circuit is the same as that shown in Fig. 9 and like reference numerals indicate like parts.

In each of Figs. 8 and 9 there is a dot and dash line 256 which is to designate that that portion of the circuit which is below the line may be positioned at a point remote from the machine itself, and the usual plug and socket connections may be used to connect the controls to that part of the machine which they control. Furthermore, all of the elements of the control circuit illustrated below these lines 258 may be included in a single control box 258 such as that shown in Figs. 1, 2, and 3. The control box 258 may be located on the machine or at some remote point where it may be readily accessible to the operator.

trating proper connections for supplying current 76 The operation of this apparatus will now be described in sofar as it is concerned with the heating and drying of'plastic material, it being understood, of course, that this machine is quite capable of being used for similarly processing other granular material.

The apparatus is conditioned for operation by first turning on the lamps 52 through the switch 222 and adjusting the current controller 224 so that a proper amount of heat is obtained. The lamps are turned on prior to passing any material through the oven section so that the plate 86 will be heated to a considerable extent, storing therein a certain amount of heat which will be used in processing the plastic material. At the same time, the adjustment screw I16 is turned so that the proper distanc between the opening I82 in the lower end of the hopper and the upper surface of the plate 86 will be obtained when the hopper is in its lowermost position. A hopper I4 filled with the particular plastic to be processed is positioned on the machine by slipping the studs I54 into the bayonet slot I58 in the plate I56. As soon as the hopper is in position the gates I86, I88 should be lowered and the hopper gate I50 opened to spill the material onto the surface of the tray I8. The machine is now ready for actual treatment of the material. The

switches

236 and 240 controlling the vibrator and the blower circuits are closed, and the speed of the vibrator is regulated by the knob 238 so that the proper rate of flow of plastic material through the tray I8 will be obtained and maintained. This rate of flow can be a mere trickle. or it can be to such an extent that the tray I8 will be substantially filled. The rate of flow depends upon the amount of heat which is necessary to remove the excess moisture and to preheat the granules of plastic. v Once the machine has been adjusted for a particular plastic it will operate until the hopper is empty, unless sooner shut off. This form of operation is generally used when the apparatus feeds directly into the hopper 22 of a molding machine I2 such as illustrated in Fig. 1.

When the machine is being used to fill the trays 22 'as shown in Fig. 2, it might become necessary during the changing of the trays 22 to terminate the operation of the vibrator for an instant. However. the arrangement of the trays in Fig, 2 is such that it should not be necessary gumming of the reflective surface of the insulated panel 62 and the exposed surfaces of the lamps 52. This removal is important because the heat of these bulbs will fuse any particles of plastic which would rise and contact their exposed surfaces. i

If it is desired to change from the treatment of one plastic to the treatment of an entirely different plastic, or to the treatment of a plastic of the same class but of different color before the hopper lb has been emptied, the gate I is pushed to closed position cutting off the supply of plastic from the hopper .to the tray. Because a small amount of plastic granules will be in section I48 of the hopper, the tray is further vibrated under the action of the vibrator until all of the plastic which was being treated is removed fro the portion I48 of the hopper and from the tray I8 and is deposited either in the hopper 20 of the molding machine or in one of the trays 22. The machine is thus self-cleaning because the tray I8 has no internal projections which would cause piling up of little mounds of plastic granules at any point. When no more plastic is being fed from the outlet end of the tray I8 the vibrator circuit is broken and also the blower circuit. If desired the lamps 52 can be left on to restore to the tray I8 whatever heat may have.

been lost during the previous treatment. The hopper I4 is removed by lifting it vertically to clear the lower edge of the hopper from the end 92 of the tray and then swinging it outwardly to remove the stud from the bayonet slot. Another hopper containing another plastic can immediately .be slipped into place and the operation continued by moving the switches in the blower and vibrator circuits to closed position.

While I have described the present invention particularly in connection with the plastic industry, it will be apparent that this apparatus has other uses in connection with drying other granular materials. Consequently, there is no intention to limit the use of this machine to processing powdered plastics. Further, I have described the preferred and only one commercial embodiment of this machine, and it will be apparent to those skilled in the art that numerous modifications and small changes may be made in this apparatus without departing materially from the spirit and scope of my contribution to this art. I, therefore, wish to be limited only by the scope of the appended claims. What I claim as new and desire to secure by United States Letters Patent is:

1. Apparatus for drying and heating granular material in a continuous flowing stream, comprising a frame, a tray mounted on said frame so as to be vibrated without imparting substantial vibration to said frame, a vibrator mounted on the under side of said tray for vibrating said tray forwardly and rearwardly parallel to the direction of flow of the granular material, means for feeding the granular material to said tray, a plurality of heating lamps carried by said frame and arranged to direct their rays toward the surv face of said tray and the granular material thereon, means forming a plurality of walls supported by said frame and enclosing said lamps so as to form with said tray a tunnel-like space, the wall adjacent said lamps and opposite said tray having a reflective surface, and blower means for passing a stream of air between said plurality oflamps and said tray to remove the moisture and evaporated volatile substance given off by the heated material.

2. Apparatus for drying and heating granular material in a continuous flowing stream, comprising frame means, an internally smooth tray mounted on said frame means and slanted down toward its outlet enl and adapted to convey the granular material through the apparatus, said tray being mounted for vibratory movement, means for vibrating said tray forwardly and rearwardly in a direction parallel to the di-;

rection of the flow of the granular material, a plurality of heating lamps having an insulated reflective panel filling the spaces between the lamps'resiliently mounted on said frame means to direct the heat rays from said lamps toward.

said tray, panel means closing both sides and the outlet end of the apparatus, a hopper mounted at the inlet end of the apparatus and adapted to feed the granular material to said tray at an even rate, and a blower for circulating air through the space between said tray and said lamps to remove the moisture and evaporated volatile substances given off by the heated granular material.

3. Apparatus for drying and heating granular material in a continuous flowing stream, comprising a frame, a slanted tray mounted on said frame so as to be vibrated without imparting substantial vibration to said frame, means for vibrating said tray forwardly and rearwardly parallel to the direction of flow ofthe granular material, a plurality of heating lamps supported by said frame and mounted so as to direct their heat rays toward said tray, a plane heat insulated reflective panel filling the space between said lamps and mounted on said frame and spaced from said tray, a hopper having a small outlet opening at its lower side for feeding the granular material to said tray at an even rate, means mounting said hopper on said frame so that its outlet is above the higher end of said tray, and means including a wall forming member closing one end of said frame, a pair of wall members carried by said frame and arranged at the sides of said tray for closing the sides of said frame, whereby a tunnel-like space is formed by said tray, said panel, said wall forming member and said pair of wall members, and a blower for passing a stream of air through said space and between said lamps and said tray to remove the moisture and evaporated volatile substances givenofi by the material being heated and dried.

4. Apparatus for drying and heating granular material in a continuous flowing stream, comprising a frame, a slanted tray mounted on said frame for longitudinal vibratory movement,.

means for vibrating said tray forwardly and rearwardly parallel to the direction of flow of the granular material, a plurality of heating lamps supported by said frame and mounted so as to direct their heat rays toward said tray, a plane:

heat insulated reflective panel filling the spaces between said lamps and mounted on said frame and spaced from said tray, a hopper having a small outlet opening at its lower side for feeding the granular material to said tray, a wall forming member closing one end of said frame, adjustable means mounting said hopper on said wall forming member so that its outlet is above the higher end of said tray, said last mentioned means including a pair of slotted plates carried' by said hopper, a pair of studs carried by said member and engaging in said slots, a thumb screw carrying element on said member, a bearing plate on said hopper above said element anda thumb screw threaded into said element so that its upspace and between said lamps and said tray to remove the moisture and evaporated volatile substances given off by the material being heated:

and dried.

5. Apparatus for drying and heating'granular material in a continuous flowing stream, comprising an enclosed housing. a tray having inlet and outlet ends mounted in said housing and through, a plurality of infra-red lamps mounted in said housing and positioned to direct infrared rays upon said tray and upon the granular material carried thereby, means forming a chimney positioned at one end of said housing so that the lower inlet end of said chimney is adjacent the inlet end of said tray, blower means positioned to introduce clean air into said housing between said tray and said lamps and to remove impurities through said chimney, a hopper having its outlet opening positioned above the inlet end of said tray, and means for removably mounting said hopper on said chimney forming means, said mounting means including means for adjusting the height of said hopper so as to regulate the rate of flow of the granular material from said hopper into said tray.

6. Apparatus for drying and heating granular material in a continuous flowing stream, comprising frame means, a housing enclosing said frame means, a tray mounted within said housing and upon said frame means and adapted to carry the granular material therethrough, said mounting comprising suction cups secured'to the underside of said tray'and to said frame means, and a plurality of infra-red lamps mounted in said housing to direct infra-red rays upon said tray and upon the granular material carried thereby, and means for vibrating said tray forwardly and rearwardly in a direction parallel to the flow of granular material so as to cause all portions of the material to be exposed to the direct rays of the lamps or to contact said tray.

7. Apparatus for drying and heating granular material in a continuous flowing stream, comprising a frame, a housing enclosing said frame and provided with inlet and outlet openings, an internally smooth tray mounted on said frame within said housing and projecting through said openings, said tray being slanted down toward the outlet end thereof so as to convey the granular material through said housing, said tray being mounted for vibratory movement, means for vibrating said tray forwardly and rearwardly in a direction parallel to the direction of the flow of the granular material, a plurality of spaced heating lamps having a heat insulated reflective panel filling the spaces between the lamps, said lamps being mounted within said housing so as to direct theirheat rays toward said tray, a hopper removably mounted on the outside of the housing and having an outlet opening above the inlet end of said tray, said hopper adapted to feed the granular material to said tray at an even rate, and a blower for circulating air through said housing and the space between said tray and said lamps to remove the moisture and evaporated volatile substances given off by the heated granular material.

WILLIAM J. MISKELLA.

REFERENCES orrnn The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS (Other references on following page) Number Number 14 Name Date Weyandt July 6, 1943 Weyandt Jan. 25, 1944 Goodwin et a1 Apr. 25, 1944 Olsen May 23, 1944 Naeher et a1. Aug. 15, 1944 Naeher et a1 Aug. 15, 1944 Muller et a1 Oct. 10, 1944