US3267588A - Grain dryer - Google Patents

Description

Aug. 23, 1966 w. A. TIMMONS, JR

GRAIN DRYER 5 Sheets-Sheet 1 Filed Sept. 18, 1963 INVENTOR WILLIAM AWMMONSJR.

Arrow/2Y5 5 Sheets-Snee't W. A. TIMMONS, JR

GRAIN DRYER INVENTOR.

ATTORNEYY Aug. 23, 1966 Filed Sept.

Aug. 23, 1966 w. A. TIMMONS, JR

GRAIN DRYER 5 Sheetsfiheet 3 Filed Sept. 18, 1963 INVENTOR WILLIAM ATMMoNsJR.

A TTO/P/VEVS United States Patent 3,267,588 GRAIN DRYER William A. Timmons, Jr., 6345 Antioch Road, Merriam, Kans. Filed Sept. 18, 1963, Ser. No. 309,782 3 Claims. (Cl. 34174) This invention relates to forced air continuous flow grain dryers, and more particularly to novel improvements for increasing the capacity thereof.

The principal objects of the present invention are: to provide a grain dryer of the above type so constructed that the drying and cooling air flow rate may be substantially increased without blowing grain from the apparatus; to provide such a device having an unusually large drying and cooling capacity in a relatively small space; to provide such grain drying apparatus which offers the benefit of frequent, eflicient grain path splitting and substantially continuous movement along the entire flow path for producing uniform drying in the drying portion without overheating; to provide such apparatus which minimizes the danger of fires in the grain during drying; to provide such a device which uses curved or parabolic intake and exhaust air flow ducts which are closed but perforated at the bottom as well as the top portions for forcing drying and cooling air with more even distribution through the flowing grain; to provide such an apparatus which has high air fiow rates without separating large quantities of dust and fine particles from the grain; to provide such a grain dryer which is self-cleaning with no ledges or obstructions to retard grain flow or to hang up trash; and to provide such a device which is relatively simple and inexpensive in construction and reliable in use.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.

FIG. 1 is a side elevation of a grain dryer embodying this invention with portions broken away to show the interior thereof and air flow paths therethrough.

FIG. 2 is an end elevation of the grain dryer with portions broken away to show air flow paths and grain flow discharge gates.

FIG. 3 is a detailed fragmentary side elevation on an enlarged scale showing the covered end of an air flow duct.

FIG. 4 is a fragmentary end elevation on an enlarged scale particularly illustrating the air flow pattern between adjacent inlet and outlet ducts.

FIG. 5 is a fragmentary end elevation on an enlarged scale showing the oscillating discharge gates and adjacent parts.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates a portable grain dryer, however, the dryer 1 may be of the stationary variety without departing from the scope of this invention. The dryer 1 is of the continuous grain flow type having an elongated upwardly extending body 2 resting, in the illustrated example, on suitable wheels 2'. The body 2 includes a pair of oppositely positioned spaced apart air inlet and air outlet walls 3 and 4 respectively and side walls 5 and 6 connected between the walls 3 and 4. The air inlet wall 3 and outlet Wall 4 respectively have several rows 7 of horizontally aligned vertically staggered spaced apart outwardly flanged openings 8. A plurality of spaced apart parallel horizontal air flow ducts generally designated 9 respectively extend between the inlet and outlet walls 3 and 4 and are mounted at opposite ends thereof in the flanged openings 8 by means of suitable screws and mating nuts 10 forming horizontal rows of said ducts which are vertically staggered and are easily removed for service and/ or replacement by removing the screws and nuts 10. Blanks or caps 11 in selected positions are also engaged by the screws and nuts 10 and plug the ends of alternate rows of the ducts 9 at the outlet wall 4 forming inlet ducts 12 open only at the inlet wall 3. Additional blanks or caps 13 plug the ends of the remaining or alternate rows of ducts at the inlet wall 3 forming outlet ducts 14 open only at the outlet wall 4.

Sheet metal walls 15 are fixed to the body 2 at the inlet wall 3 and form an inlet chamber 16 communicating with the inlet ducts 12. Sheet metal walls 17 are fixed to the body 2 at the outlet wall 4 and form an outlet chamber 18 communicating with the outlet ducts 14. A ring or cage member 19 is mounted on the sheet metal walls 17 and forms a circular passageway 20 communicating with the outlet chamber 18. A fan 21, in the illustrated example of the axial flow blade type, is rotatably mounted in the ring member 19 by means of a suitable shaft 22 and supported by conventional bearings 22 having a pulley 23 fixed thereto. A belt 24 is operatively engaged with the pulley 23 and also with a pulley 25 mounted on and driven by a motor 26 or a suitable power take-off shaft (not shown) for rotating the fan 21. The fan 21 causes air to flow outwardly through the passageway 20 in the direction indicated by the arrows 27 which results in the exhausting of air from the outlet chamber 18. This drops the pressure in the chamber 18 and induces flow through the ducts 12 and 14 as noted below.

A fixed bafiie plate 28 extends outwardly and downwardly from the air inlet wall 3 and divides the inlet chamber 16 into an upper portion 29 communicating with the inlet ducts 12 at the upper portion of the body 2 and a lower portion 30 communicating with the inlet ducts 12 at the lower portion of the body 2.

A burner assembly 31 which may be fired by any suitable fuel is mounted in the inlet chamber 16 and normally communicates only with the chamber upper portion 29 due to the normal position of a hinged bafiie plate 32 adjacent the bafiie plate 28. The baffle plate 32, however, is movable about a hinge 33 to a position indicated by the broken lines at 34. The movement of the battle plate 32. is by means of suitable pivoted links 35 and 36, the latter being manipulated by a handle 37. When the baffle plate 32 is in the position indicated by the broken lines at 34, the burner assembly 31 communicates also with the chamber lower portion 30. A suitable hinged screen 38 provides access to the handle 37 and an opening into the inlet chamber 16 permitting air to enter through separate paths into the upper and lower portions 29 and 30 when the baffle plate 32 is in the vertical position illustrated. When the battle plate is in the position at 34, all air entering the chamber 16 is forced past the burner 31 resulting in heated air entering both the upper and lower portions 29 and 30.

The exterior surfaces of the inlet and outlet ducts 12 and 14 and the interior surfaces of the inlet and outlet walls 3 and 4 and side walls 5 and 6 define a duct-interrupted grain flow chamber 39 through which the grain flows downwardly over the respective ducts. A grain inlet hood or garner 40 is secured on the body 2 at the upper end thereof and communicates with the grain flow chamber 39. A suitable grain feeding device such as a screw conveyor 41 communicates with the hood all for continuously depositing grain 42 into the flow chamber 39.

A plurality of discharge funnels 43 direct the grain 42 at the bottom of the how chamber 39 to oscillating grain discharge gates 44 which permit the grain to fall therepast at a predetermined adjustable rate into a discharge hopper 45 secured to the body 2 beneath the gates 44. A suitable conveyor device, in the illustrated example, a screw conveyor 46, communicates with the discharge hopper 45 for carrying the dried grain away from the dryer 1.

The discharge gates 44 are supported between pairs of pivotally mounted end plates 47 for rocking in an arc about respective pivot points 48. The end plates 47 are tied together by rods 49 pivotally secured respectively thereto. A push arm 50 is pivotally secured at one end thereof to a rod 4%. The other end of the push arm 50 threadedly engages a screw 51 at 52 for vertical adjusting movement along a slot 53 formed in a rocker arm 54. The screw 51 is manually rotatable by a knob 51' reached through an access door 52. The rocker arm 54 is pivotally secured to the body 2 centrally of the slot 53 at 55 and a push rod 56 is pivoted at one end thereof to the rocker arm 54 below the slot 53. The push rod 56 is pivotally mounted at the other end thereof to a rotating link 57fixed to a shaft 58 which forms the output of a gear reducer 58'. The input shaft of the gear reducer 58 supports a pulley 59 which is engaged with a belt 60 also engaging a pulley mounted on the motor 26 or power take-off shaft (not shown) whereby the discharge gates 44 are operated together with the fan 21. A shear pin or similar device (not shown) is associated with the rotating link 57 for automatically disengaging same if a foreign object should jam the discharge gates.

The ducts 12 and 14 when viewed in cross-section respectively form closed figures which are symmetrical about a central vertical plane extending longitudinally of the duct. The ducts are generally parabolic on each side with the vertex 61 thereof midway between the top 62 and bottom 63 thereof. This renders the top and bottom of the ducts pointed while the sides curve smoothly continuously outwardly and downwardly to the vertical center or vertex and then inwardly to the bottom. Due to this configuration, the path of the grain 42 flowing downwardly through the grain flow chamber 39 is split and smoothly flows around the individual ducts as indicated by the arrows 64. The walls 65 of the ducts are preferably sheet metal of approximately ZO-gauge in thickness and perforated with -inch staggered holes 66 on -inch centers over substantially the entire surface thereof. This permits air flow outwardly through the walls of the inlet ducts l2 and inwardly through the Walls of the outlet ducts 14.

In operation, the grain 42 is directed into the inlet hood 4t) by the screw conveyor 41 from which it falls into the grain flow chamber 39. The flow chamber 39 is permitted to fill without oscillation of the discharge gates 44 whereby the grain initially deposited forms a stationary batch surrounding the respective ducts 12 and 14. The baflie plate 32 is then moved by means of the handle 37 to the position indicated by the broken lines at 34 and the burner assembly 31 is actuated along with the fan '21, the discharge gates 44 remaining stationary. Heated drying air is thereby drawn through the entire grain batch by induction which causes the heated air to enter into all the inlet ducts 12, how out of the inlet duct perforations through the grain 42, enter into the perforations on adjacent outlet ducts and flow from the respective outlet ducts into the outlet chamber 18 where it is exhausted through the passageway 20. After several minutes of batch operation, the battle plate 32 is moved back to its vertical position and, after a pause, in order for the lower portion of the grain to cool, the gates 44 are actuated by rotating the screw knob 51 along with actuating the screw conveyor 46 for inducing a continuous downward flow of grain through the flow chamber 39. The air heated by the burner 31 is now restricted to the ducts communicating with the upper portion 29 of the inlet chamber 16 and air entering the lower portion fit) is of ambient temperature for cooling the grain in the lower portion of thefiow chamber 39. Cool dried grain is then continuously delivered into the hopper 45.

A significant advantage of this invention results from the air flow pattern produced by the configuration of the inlet and outlet ducts. Because the ducts are closed to the grain except for small perforations, high flow rates may be used without blowing grain through the outlet ducts into the outlet chamber 18 which often occurs with the well known open-bottom baflle type of dryer. Most important, the curved configuration coupled with the perforated duct walls produces fiow patterns 67 which move in generally radial lines or lines normal to wall tangents both into and out of the grain between adjacent inlet and outlet ducts. This exposes a much greater percentage of grain to drying air at any one instant than prior art duct type dryers permitting more efiicient and homogeneous removal of moisture without the need for excessively high temperature air which would have adverse effects on the grain. The flow patterns 67 are produced without forming a grain dead spot at the top 62 of the ducts which would occur if the ducts were round in crosssection instead of pointed at upper and lower ends. This duct cross-sectional configuration also offers less grain resistance to downward grain flow while efficiently inducing grain fiow splitting for better grain exposure without causing a drop-away or unfilled area immediately beneath the respective bottom portions 63.

Due to the more uniform distribution of drying air throughout the grain, the maximum air velocity may be maintained without sacrificing etficiency at a low enough rate so that excessive dust is not dislodged which would cause an unwanted weight loss in the grain, poor working conditions around the apparatus and sometimes the possibility of fire in the grain. The staggered positioning of the ducts, along with the unique cross-sectional shape and perforations, also produces a continuous turning of the grain which further increases uniform grain drying and higher quality in the dried grain. It is estimated that the air fiow in the above-described grain dryer may be increased approximately three times over the usual open-bottom baflie type grain dryer resulting in an increase of the drying and cooling capacity by approximately 300 percent.

It is to be understood that while one form of this invention has been illustrated and described, it is not to be limited to the specific form or arrangement of parts herein described and shown except insofar as such limitations are included in the claims.

What I claim and desire to secure by Letters Patent is:

1. In a grain dryer, a grain-containing chamber having a plurality of generally horizontally extending inlet and outlet air ducts extending therethrough, said ducts each being closed in cross-section with the top and bottom thereof pointed vertically and the side curving smoothly continuously outwardly and downwardly from said top and then inwardly to said bottom, said ducts having walls. perforated with spaced apart air-transmitting holes, said holes being of a size unable to pass grain therethrough.

2. The apparatus as set forth in claim 1 wherein said ducts are generally parabolic on each side with the vertex thereof midway between said top and bottom.

ducts are vertically pointed and the sides thereof curve smoothly continuously outwardly t0 the vertical center thereof and then inwardly to said bottom, said ducts being adapted for splitting the downward flow of grain thereover, said ducts having walls of sheet metal perforated with staggered holes over substantially the entire surface thereof, said holes being of insufiicient size to admit grain.

References Cited by the Examiner UNITED STATES PATENTS 260,567 7/1882 Hawkenson 34174 336,905 3/1886 Ehlermann et al. 34--174 1,239,216 9/1917 Randolph 34174 FOREIGN PATENTS 459,127 10/1913 France.

10 FREDERICK L. MATTESON, JR., Primary Examiner.

NORMAN YUDKOFF, Examiner.

F. E. DRUMMOND, Assistant Examiner.

Claims (1)

1. IN A GRAIN DRYER, A GRAIN-CONTAINING CHAMBER HAVING A PLURALITY OF GENERALLY HORIZONTALLY EXTENDING INLET AND OUTLET AIR DUCTS EXTENDING THERETHROUGH, SAID DUCTS EACH BEING CLOSED IN CROSS-SECTION WITH THE TOP AND BOTTOM THEREOF POINTED VERTICALLY AND THE SIDE CURVING SMOOTHLY CONTINUOUSLY OUTWARDLY AND DOWNWARDLY FROM SAID TOP AND THEN INWARDLY TO SAID BOTTOM, SAID DUCTS HAVING WALLS PERFORATED WITH SPACED APART AIR-TRANSMITTING HOLES, SAID HOLES BEING OF A SIZE UNABLE TO PASS GRAIN THERETHROUGH.

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