US1374874A - Process and apparatus for drying materials - Google Patents

Description

E. BASSLER. PROCESS OF AND APPARATUS FOR DRYING MATERIALS.

APPUCATION HLED MAR, 2A. l9l6- RENEWED JUNE TS. 1919.

Patented Apr. 12 192 1.

E. M, BASSLER.

PBOCESS OF-AND APPARATUS FOR DRYING MATERIALS. APPLICATION FILED v1.24. I916- RENEWED JUNE-216.1919.

1,374,874. Patented Am-. 12 1921.

6 SHEEIS-SHEET 2.

. E. M. BASSLER.

PROCESSOFAND APPARATUS FOR DRYING MATERIALS. APPLICATION EILED MML'24, I9l6- RENEWED JUNE 15, I919- 1,374;3j74, Patented Apr. 12, 1921..

6 SHEElS-SHEET 3.

E. M. BASSLER.

I PROCESS OF AND APPARATUS FOR DRYING MATERIALS. APPLICATION FILED MAR. 24,'isl6. RENEWED JUNE :6. 1919. 1,374,874.

Patented Apr. 12, 1921. 4

6 SHEETS-SHEET 4- E M. BASSLER. PROCESS OF AND APPARATUS FOR, DR Yl NG MATERIALS. APPLICATION FILED MAR 24, l;9 l 6-' RENEWED JUNEJG. 1919- 1,374,874. mama Apr. 12, 1921, s snms-snm 5.

umrso STATES nnwm u. mssnna, or MILWAUKEE; Wisconsin,

mcnss AND Arrm'rnsroa DRYING mn'rnms.

Specification of Letters Patent.

Patented Apr. 12, 1921.

Application filed larch B4, 1918, Serial No. 86,368. Renewed June 16, 1919. Serial No. 804,725.

To an whom it mag concern."

Be it known that I, EDWIN M. ,BASSLEB, a citizen of the United States, and resident of Milwaukee, in the county of Milwaukee and State of -Wisconsin, have invented a new and 'useful Process of and Apparatus for Drying Materials, of which the following is a specification.

This invention relates to a process ofand apparatus for drying materials.

As my invention relates to a process of drying materials, the object of the inven-,

tion is to provide an improved process of drying material by means of a forced circulation of hot air, whereby the drying of the.

material may proceed 'as a continuous operation, and whereby, also, the material when thoroughly dried will be cooled tosuch an extent that it willbe in condition forjpacking or storing.

As my invention relates to improved apparatus for practising said process, the object of the invention is to provide means for conveying the material to be dried in the form of a laye.- of desired thickness, together with means for creating and passing a current of air heated to a desired high temperature monsistent with. safet from combustion, successively through said layer of material in the reverse direction to that in which said layer of material is being conveyed, said means for creating-a current ofquired for raising, said air to the desired initial temperature.

To effect the foregoing objects, my improved process and apparatus comprise the various features, combinations of. features and details of construction hereinafter described and claimed.

In the accompanying drawings,

in which my invention is fully illustrated,

Figure l is a side View of the admission end of a conveyer forming part of a drying apparatus of my invention adapted for the practice of my improved rocess.

Fig. 2 is a side viewo a ortion'of said conveyer intermediate its on s.

Fig. 3 is a side view of the discharge end of said conveyer showing the machinery for driving the conveyer and other apparatus assoclated with said conveyer.

Fig. 4 1s .a sectional side View of the discharge end of (the conveyer ,on the line 44 of Fig. 6.

' Fig. 5 is a top plan view of a portion of mission end of the conveyer.

Fig.-.9 is a fragmentary top plan view of the conveyer belt from the. F1 8;and

1g. 10 is a fragmentary View of the maposition 9--9,

' .chinery house showing an adjustableventilator for admitting air to said machinery house.

In the accompanying drawingsl have, for purpose of illustration, shown an apparatus for the practice of my improved'process particularly designed and adapted for drglng alfalfa and the like.

aid apparatus comprises a' conveyor designated, as a whole A, which comprises a trunk or casing B, preferably rectangular 1n crosssection, and a conveyer belt 0 mounted within said trunk or casing and which extends lengthwise through the same. As shown, said conveyer. belt C is of a familiar type comprising chainbelts 1 and 2 at opposite sides of .said conveyer belt, which are adjusted to sprocket wheels 3 and i rotatably mounted at the admission and discharge ends, respectively, of the trunk or casing B both the upper and lowerlaps of which are supported on track rails 5,5, by means of brackets 6 secured to links of said chain belts at spaced. intervals, said brackets having anti-friction rollers 7 mounted at the ends thereof which run upon said track rails 5, 5.

Secured to the links of said chain belts 1 and 2 are slats 8, which form the supporting or carrying surface of said conveyer belt C. Where the chain belts 1 and 2 are spaced a considerable distance apart, as in apparatus for drying alfalfa and the like, said slats 8 are also preferably secured in proper spaced relation by means of a canvas belt- 9 to which said slats 8 are bolted or riveted between the chain bolts 1 and 2.

'Said canvas belt 9 is adjusted to pulleys 10 and 11 rotatably mounted at the admission and discharge ends of the conveyer, corresponding to the sprocket wheels 3 and 4, respectively.

As shown the sprocket wheels 3 and pulleys 10 at the admission end of the conveyer are mounted on an idle shaft 12, while the sprocket wheels 4 and pulley 11 at the d1scharge end of the conveyer are secured to rotate with a shaft 13 which is adapted to be driven by means of driving connection with a suitable source of power, preferably through the medium of a variable speed device, in the manner presently described To provide for maintaining a desired tension on the conveyer belt C, the shaft 12 is mounted in suitable take-up boxes, indicated at c, a, mounted at the admission end of the conveyer trunk'or casing. Any desired or approved take-up device, of which several different kinds are available, and may be purchased in the open market, may be used for this purpose and need not, therefore, be described in detail.

The conveyer trunk or casing B is preferably cut away for a considerable distance longitudinally thereof above the top lap of the conveyer belt C at both the admission and discharge ends of said conveyer, thus exposing the carrying surface of said conveyer belt C and reatly facilitating depositing the materizfi to be dried upon said conveyer belt at the admission end of the conveyer and its removal therefrom at the discharge end of the conveyer. In a machine for drying alfalfa and the like, which is of considerable len h-a desirable size being about 150 feet rom center to center of the sprocket wheels 3 and 4-said casing B will preferably be cut away for from 14 to 16 feet at both its admissionand discharge ends.

The trunk or casing B is preferably made of sheet steel and is reinforced or strengthened by cleats or 'braces 14 secured thereto at intervals of a few feet throughout its length and, excepting as hereinafter particularly pointed out, the sides of said trunk or casing are entirely closed. Also, to prevent excessive loss of heat from radiation, I contemplate covering the exterior of the conveyer trunk or casing B with a layer of asbestos or other suitable non-conductor of heat.

The conveyer A is supported upon a suitable foundation, consisting, preferably, of wood sills 15 which extend lengthwise of the conveyer, trunk or casing B and which are preferably embedded in a concrete floor b, the concrete imparting stability to the structure and the sills 15 affording convenient means for making attachments to said foundation.

Secured to the tsides of the conveyer trunk or casing B above the conveyer belt C and B, substantially concentric projecting inwardly over th lateral ed es of said conveyer belt and in closeproximity to the upper surface. thereof are guards 16. Said guards are preferablytmade of sheet metal and are inclined, forming, in effect fillets which close the spaces between the lateral edges of the conveyer belt C and th sides of the conveyer trunk or casing B, thus preventin the conveyed material from falling throug said spaces.

The front or admission end of the conveyer trunk or casing B above the conveyer belt C is open and the rear end thereof is closed preferably b means comprising a member which is reely movable toward and from the conveyer belt 0, gravity operating to maintain said member in contact with said conveyer belt or the material thereon, thus permitting said member to adjust itself automatically to varying thicknesses of the layer of material to be dried, supported on said conveyer belt. In the drawings, the line 0 indicates the top of the layer of conveyed material:

As shown the closing means or closure for the rear" or discharge end of,said conveyer comprises a drum 1? which is 'adaptedto ride upon theexposed upper surface of the conveyer belt Cor of the layer of material supported thereon, defined by the line 0 and which is mounted to rotat freely in the ends of arms 18 pivoted at 19 to the outer sides of the conveyer trunk or casing B. The drum 17 is counter-balanced by means of counter-weights 20 on the arms 18, said counter-weights being preferably adjustable lengthwise of said lever arms, thus providing for varying the ressure of said drum on the'conveyer belt andthe material supported thereon, so that the weight of said drum shall not break or injure said conveyed material. The surface of said drum runs in close proximity to the surface of a segmental shield 21 secured in fixed position on the rear end ofthe trunk or casing with the pivots 19 of the lever arms 18. Said shield 21 is continuous between th sides ofthe conveyer trunk or casing B and the ends of the drum 17 extend into close proximity to the sides of said trunk or casing. Attached to the shield 21, preferably adjacent to its upper edge, is

a curtain 22 which depends at the front or inclosed side of the drum 17.. The lower edge ofsaid curtain is preferably weighted and the air pressure within the conveyer trunk or'casing will operate, in an obvious manner, to hold said curtain 22 in contact with the surface of the drum 17, thus effectively closing the space between said drum and the shield 21 and also the rear or dis-' charge end of the conveyer trunk or casing B above the conveyer belt C or the layer of material whichv may be supported thereon,

without interfering with the movement of the conveyed material. As shown, slots-23,-

strength, and-the surfaces thereof are cov-- ered with duck, canvas Or thelike to render them tight. I

Also, to prevent the escape of air at the discharge end of the conveyertrunk or casing B, the space within said casing beneath the upper lap of the conveyer belt C is shut off or closed'by means of a transverse partition 24, preferably made of canvas, and which comprises separate sections spaced apart to form an opening for the passage of the lower lap of the conveyer belt C, the edges of said partitions extending into close proximity to'the upper surface of the lower lap of said conveyer belt and to the under surfaces of both the upper and lower'laps thereof. l v

The currentofair passing through the conveyer trunk or casing B is caused to pass successively through the layer of material supported on the conveyer belt C by means of transverse partitions located above the conveyer belt C and other partitions 26 located beneath the upper lap of sald conveyer belt, said partitions 25 being located intermediate the partitions 26 and being so arranged that air entering said trunk or casing adjacent to its discharge end and below the upper lap of the conveyer belt will be caused to pass directly upward through the conveyer'belt and the material supported thereon, v

Said partitions 25 and 26 are preferably made of canvas,the partitions 25 being made in the form of curtains and of such length that they will rest lightly on the upper surface of the conveyer belt when there is no material supported thereon, and the free lower edges thereof will be carried rearwardly by the material being conveyed, the lower edges of said curtains 25' being weighted so that the current of air passing through the conveyer trunk or casing will not blow said curtain partitions with it, which'would permit the current of air to pass freely through the trunk or caslng above the upper lap of the conveyer belt and the material conveyed thereby. The partitions 26 are fixed and are substantially similar to the partition 24 heretofore described, comprising separate'sections spaced apart to form openings in said partitions to permit the passage therethrough of the lower lap of the conveyer belt.

As preferably constructed, there Wlll be four partitions below the conveyer belt C, comprising the partition 24 in line with the closed rear or discharge end of the conveyer trunk or casing, a partition 26 substantially in line with the inclosed front end of said conveyer trunk or casing, and two partitions 26 located substantially equidistant from each other and from the -efhd partitions '24 and 26. As shown, also, thepartitions 25 are located equidistant between the end and intermediate partitions 24 and 26 at the under side of said conveyer; belt. It will be understood that the number of said deflecting partitions may be changed as desired and also their arrangement. Forexam Ie, the hot air can equally well be admitted to the conveyer trunk or casing B above the conveyerjbelt C and discharged therefrom "either above orbelow said conveyer belt, as preferred. The necessary changes in ar-v vr'a'ngement of said partitions to cause the air passing throu h said conveyer trunk to traverse any desired path, can readil be made by any skilled mechanic and nee not, therefore, be described in-detail.

To render. the interior of the conveyer trunk or casing below the conveyer belt readily accessible, openings are formed at intervals in the sides of said trunk 'or casing,said

openings being controlled by suitable. 010- sures, consisting, as shown, of slides 27, movably supported in suitable guides formed on the said conveyer casing adjacent to the lateral edges of said openings.

As shown, the conveyer belt C is drivenbelt e adjusted to sprocket wheels e}, e secured to rotate with the driving shaft of the transmission E and with the worm shaft F, respectively, and a worm f on said shaft F which mes es with a worm wheel G secured to rotate with said shaft 13. r v

A desirable form of'variable speed transmission E is that lmown to the trade as a Reeves Class A variable speed transmission, but an desired form of transmission maly be use referably, also, the sprocket wheel 6 for driving the worm shaft F is adapted to be secured to and disconnected from said worm shaft by means of a suitable clutch, which may be of any usual or approved form and which provides for quickly and conveniently starting and stopping the conveyer belt C.

A circulation of hot air is maintained through the trunk or casing B of the conveyer by means of a fan indicated at H, which, as shown, is driven directly from the engine D, the current of air delivered into said trunk or casing B from said fan being below the upper lap of the conveyer beltC.

In accordance with my improved process of dr ing materials, the air supplied to the fan Ii is drawn wholly or in part through the section of the conveyer belt C- which is exposed at the rear or discharge end of the conveyer beyond the end of the trunk or casing B and also through any material Which-may be contained thereon. This air being of the same temperature as the at mosphere and cold as compared with the current of air delivered into the conveyer trunk or casing B, will operate, in an obvious manner, to cool the material contained on said section of the conveyer belt. Also, said material being hot, will operate to heat the air supplied to the blower and thence to the conveyer trunk or casing B, thus efiecting a material saving in fuel necessary for heating said air.

' It is obvious that the extent to which the material on which the drier is operating at a given time will be cooled and the air drawn through said material will be heated, will depend directly 1). on the rate of travel of the conveyer belt the material being more thoroughly cooled and the air heated to a higher degree as said conveyer belt travels more slowly and thecooling of the material and the heating of the air decreasing as the rate of movement of the conveyer belt increases. Regardless of the material undergoing treatment, said conveyer belt is driven at such speed that when the conveyed material, after passing through the conveyer trunk or casing B reaches the extreme fear or discharge end of the conveyer belt 0 it will be cooled to such an extent that it can at once be packed for shipment and sale.

In the case of alfalfa, for drying which the apparatus shown in the drawings is particularly designed and adapted, the movement of the conveyer belt C is adjusted to such a speed that it will require approximately from 30 minutes to 2 hours for the material to pass through said conveyer, depending upon the initial amount of moisture in the green product, the depth of the material on the conveyer belt, and the temperature of the air.

, My invention contemplates connecting the suctionside of the blower H with the inclosed. space beneath the exposed section of 'damperat j. 1

the conveyer belt C at the discharge end of the conveyer. Sim le means for this purpose, which will a so serve to protect the engine, blower, heater etc., from the'elements, consists in inclosing said engine, blower, heater and associated devices in a house, which is substantially air-ti ht ex: cepting that it communicates direct y with the space beneath the exposed section of the discharge end of the conveyer belt by means of suitable holes or openings formed in the side Wall of the trunk or casing which incloses said space, and, where only part of the air supply for the fan or blower is to be drawn through the exposed rear end of the conveyer and the layer of material thereon, said house may be provided with an openin for admitting air directly thereto from -t e atmosphere, said opening being preferably provided and controlled by means of a suitable form of damper, by

means ofwhich the relative quantities of air admitted to the house through said opening and through the conveyer belt and the material supported thereon may be regulated as desire In the drawing said house is indicated by the dotted lines J, and the regulating My improved process and apparatus possesses many and very important advantages over the usualprocess ofsun drying or curing. In the case of hay oralfalfa, for instance, the proper sun curing of said hay depends entirely upon the weather, and even with-fine weather {results in very mate-- riall'y bleaching theh y'or alfalfa, and in case of rain or dew af er said hay or alfalfa has been partially dried, results not only in further bleaching the hay or alfalfa, but also extracts therefrom a very considerable part of its food properties. oreover, the handling of the hay in the fields when dried, re sults in a very considerable percentage of loss, varying from 15% as a minlmum to upapparatus, they, are practically not bleeched at all, but, when dried, retain their natural colors; they retain practically all of their food properties; and there is practically no shrinkage or loss in handling, as the hay and alfalfa are handled green prior to being I delivered to the drying apparatus and everything deposited upon the admission end of the conveyer belt is delivered at the discharge end thereof.

It will be observed also that with my apparatus and method, I can approximate tion of'the air at the exit end of the tunnel as well'as a gradual reduction of the temideal conditions, namely, complete saturaperature of the air, Without reheating at any sive passages throughsaid layer of material to a desired relatively low temperature at the point of. supply of the material to be dried, whereby the material to be dried will be subjected to an initial relatively low temperature and to a gradually increasing temperature as the liquid content thereof de-' creases, and attaining, a desired maximum temperature when the liquid content thereof is reduced to a desired minimum, substantially as described.

2. The process of drying materials which consists in feeding a layer of material to be dried through a trunk, passing a current of air under pressure moving through said trunk in a reverse direction to said layer of material to be dried, heated to a desired relatively high initial temperature, repeatedly alternating up and down throughsaid layer of material without reheating, thereby causing said current of air to gradually fall by successive passages through said layer of material to a desired relatively low temperature at the point of supply of thematerial to be dried, whereby the material to be dried will be subjected to an initial relatively low temperature and to-a gradually increasing temperature as the liquid content thereof decreases, andattaining a desired maximum temperature whenthe 'l1qu1d content-thereof is reduced to a desired minimum, substantially as described, a

3. The process of drying materialswhich consists in feeding a layer of material to be dried, passing a current .of air moving in a.

reverse direction to said layer of material repeatedly alternately up and'down through said layer of material, said current of air being relatively cold in its initial passa e through said material to thereby cool is e discharging dried material as well as initially heat the air, further heating said current of air to a desired maximum temperature immediately subsequent to its initial passage through said material,- and then permitting said current of air' to traverse said layer of material in the manner specified without reheating, whereby the temperature of the air will drop continuously until .it is discharged at the point of supply of the fresh material.

4. In a drying apparatus, the combinationof a trunk 'or casing, a conveyer in said trunk or casing which extends len hwise thereof and projects therefrom at 1tsdis charge end, means for closing the discharge end of said trunk or casing constructed and arranged to permit the passage of the conveyer and conveyed material, driving means 7 for said conveyer, means to create a current of air lengthwise through said trunk or casing in thereversedirection to-the direction of movement of said conveyer, part1- tions within said casing above and'below' said conveyer constructed and arranged to cause said currentof air to pass successively through said conveyer, means whereby the Y air isinitially drawn through the section of said conveyer at the discharge end of said trunk or casing which is outside thereof and which carries the hot dried product and thence forced into said trunk or casing adj acent to its discharge end, and means for heating said current of air before it passes into said trunk-or casing, substantially as described.

5. In a drying apparatus, the combination of a trunk orcasing, .a conveyer in said trunk or casing which extends lengthwise 7 thereof and pro ects therefrom at both ends,

means for closing the discharge end'of said trunk or casing constructed and arranged to permit the passage of the conve er and conveyed material, driving means fbr said conveyer, means to create a current of air lengthwise through said trunk or casing in the reverse direction to the direction of movement of said conveyer, partitions within said casing above and below said conveyer constructed and. arranged to cause,

said current of air to pass successively Y vthrough said conveyer, means whereby the air is initially drawn first through the section of said conveyer at the discharge end of said trunk or casing which is outside thereof and which carries the hot dried product and thence for'cedinto said trunk or casing adjacent to its discharge end, and means for heating said current of air before it passes into said trunk or casing, substantially as'describedi In testimony, that I claim the foregoing as my invention, I afiix my signature in presence of two subscribing witnesses this 3rd day of March A D. 1916.

. EDWIN M. BASSLER.

, Witnesses:

FmRENoE M. REIGHEL, O. VAN Dnvan'rnn.

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