GRAIN MOISTURIZER
United States Patent 3817261
A portable device is described for adding water at a predetermined rate to the hopper of a conventional, portable grain auger or elevator whereby the moisture content of the grain is increased by a desired amount as the grain is moved from storage to a predetermined location. In one embodiment a gravity feed is described whereby water from a tank flows from an outlet therein into the hopper. The water level in the tank is maintained constant by a float valve at the tank inlet controlling ingress therethrough from a source of water under pressure, the flow rate being determined by the area of a fluid passage in a flow controller positioned in the outlet. In an alternative embodiment a variable speed, motor-driven pump is utilized to supply water from the water source at a constant rate to the hopper, the rate of flow being determined by the speed of the motor. In both embodiments the magnitude of the increase in moisture is determined by the rate of flow of water into the hopper which in turn is proportional to the capacity of the grain elevator or auger used to convey the grain from the hopper.
US Patent References:
/1155977.html
Vernon - October 1915 - 1155977
Grain-treating machine
Iverson - June 1921 - 1382981
Machine for maintaining constant moisture content in a granular material
Fisher et al. - October 1935 - 2016920
Machine for the introduction of moisture to wheat or the like
Feese - June 1938 - 2120437
Portable conveyer
Gephart - April 1946 - 2397959
/1155977.html
Vernon - October 1915 - 1155977
Grain-treating machine
Iverson - June 1921 - 1382981
Machine for maintaining constant moisture content in a granular material
Fisher et al. - October 1935 - 2016920
Machine for the introduction of moisture to wheat or the like
Feese - June 1938 - 2120437
Portable conveyer
Gephart - April 1946 - 2397959
Application Number:
05/251694
Publication Date:
06/18/1974
Filing Date:
05/09/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
222/56, 99/536
International Classes:
B02B1/04; B02B1/00; B02B1/04
Field of Search:
134/25R,56R,65,68,131,132 99/536 222/56,57,71,73 118/303 259/22,25
US Patent References:
Primary Examiner:
Blum, Daniel
Attorney, Agent or Firm:
LeBlanc & Shur
Claims:
What is claimed and desired to be secured by United States letters patent is
1. A portable device for use with a portable grain conveyor, said conveyor having a hopper for receiving grain and means for conveying grain from the hopper to a predetermined location, to increase the moisture content of the grain conveyed thereby, said device comprising:
2. The device of claim 1 wherein the cross-sectional area of said fluid passage is substantially smaller than the cross-sectional area of said outlet and the internal cross-sectional area of said conduit.
3. The device of claim 1 further comprising vent means mounted on said conduit adjacent said flow regulating member and extending therethrough for communicating atmospheric pressure to the interior of said conduit immediately downstream of the fluid passage.
4. The device of claim 3 further comprising valve means carried by said conduit for controlling the flow of water therethrough.
5. The device of claim 1 wherein said tank has an inlet and said filling means includes conduit means connecting the inlet and said source of water for communicating water from said source to the interior of said tank through said inlet, said first control means comprising:
6. The device of claim 5 further comprising a float member disposed in said tank; a lever arm connecting said float member and said valve element; a fulcrum supporting said lever arm and disposed between said float and said valve element so that as the water level in said tank rises said float and lever urge said valve element into engagement with said seat, and as the water level in said tank lowers said float and lever urge said valve element out of engagement with said valve seat.
7. The device of claim 1 wherein the outlet is a port and said flow regulating means includes a plate detachably mounted in said port, said plate having an aperture therethrough defining a fluid passage, said passage having a predetermined cross-sectional area.
8. The device of claim 1 wherein said tank is positioned above said hopper.
1. A portable device for use with a portable grain conveyor, said conveyor having a hopper for receiving grain and means for conveying grain from the hopper to a predetermined location, to increase the moisture content of the grain conveyed thereby, said device comprising:
2. The device of claim 1 wherein the cross-sectional area of said fluid passage is substantially smaller than the cross-sectional area of said outlet and the internal cross-sectional area of said conduit.
3. The device of claim 1 further comprising vent means mounted on said conduit adjacent said flow regulating member and extending therethrough for communicating atmospheric pressure to the interior of said conduit immediately downstream of the fluid passage.
4. The device of claim 3 further comprising valve means carried by said conduit for controlling the flow of water therethrough.
5. The device of claim 1 wherein said tank has an inlet and said filling means includes conduit means connecting the inlet and said source of water for communicating water from said source to the interior of said tank through said inlet, said first control means comprising:
6. The device of claim 5 further comprising a float member disposed in said tank; a lever arm connecting said float member and said valve element; a fulcrum supporting said lever arm and disposed between said float and said valve element so that as the water level in said tank rises said float and lever urge said valve element into engagement with said seat, and as the water level in said tank lowers said float and lever urge said valve element out of engagement with said valve seat.
7. The device of claim 1 wherein the outlet is a port and said flow regulating means includes a plate detachably mounted in said port, said plate having an aperture therethrough defining a fluid passage, said passage having a predetermined cross-sectional area.
8. The device of claim 1 wherein said tank is positioned above said hopper.
Description:
This invention relates to a grain moisturizer and particularly to a portable device which may be used in conjunction with a conventional portable grain elevator or auger to add moisture to feed grain preferably as it is moved from a storage bin.
Following harvest, feed grains are frequently stored for extended periods of time before being moved to a commercial elevator or used for feed. The grain is normally stored in farm bins situated in close proximity to the field or to feed lots, or both. A motor-driven, portable elevator or auger is normally used to move the grain either into a bin or from a bin into a vehicle.
Portable elevators or augers for moving or conveying grain are well known and many types are commercially available. With most such devices the grain is fed into a hopper located on the ground and conveyed by the elevator or auger from the hopper into a bin or a vehicle. A grain auger may be described as a motor driven screw conveyor enclosed within a cylindrical housing. A portable grain elevator, on the other hand, utilizes individual scoops mounted on a linked metal belt disposed within a substantially U-shaped housing. The belt is also motor driven.
Following harvest the grain may be stored on the farm, depending upon the individual farmer's needs, for up to from three to four years. As will be obvious, during storage the grain dries substantially. For example, grain may be harvested with a moisture content, depending on atmospheric conditions, of from 10 to 14 percent or more. However, after storage for 3 or 4 years, this content may fall to 6 percent or less.
If the stored grain is intended for feed, a low moisture content is highly undesirable. Dry grain is less palatable, and therefore less digestable. Accordingly feed grain having a low moisture content will produce a smaller weight gain than grain having a higher moisture content.
More importantly, however, if the grain is intended for sale to a commercial elevator, a low moisture content will lower the farmer's return from the sale. For example, as a general rule the price paid for feed grain by a commercial elevator is based on the actual weight thereof. But, if the grain contains over the maximum specified moisture, a penalty of one cent per bushel for each one quarter percent excess is exacted. However, if the grain has less than the maximum moisture content, a corresponding credit is not allowed, and the sale price is determined by the actual weight at the time of delivery.
Therefore, from an economic standpoint, it is important to market or feed grain having nearly the maximum moisture content. To do so, however, the moisture content must be accurately measured, and then a precise quantity of water must be added to the stored grain at or near the time the grain is to be fed or transported for sale.
Many procedures are known for evaluating the moisture content of a grain sample. For example, the sample may be weighed, heated to drive off the moisture, and then reweighed to establish a dry weight value. The change in weight for the sample divided by the sample weight, multiplied by 100, will be equal to the percent moisture content.
Another well known method for evaluating the moisture content is based on a measurement of the electrical conductivity of the grain sample. This conductivity may then be compared with known values. For example, the measured conductivity of an unknown sample may be used to find its moisture content on a graph plotting moisture content versus conductivity.
Many devices are available commercially for measuring the moisture content according to these and other well known principles.
It will be apparent that when the moisture content and the weight of the grain are known, the latter being determined by the capacity of the bin and the density of the grain, the quantity of water to be added may be easily calculated. However, while the quantity of water to be added may be calculated without difficulty, a satisfactory device for moisturizing stored grain has not been known prior to the instant invention. For example, water may not be sprayed into the bin on top of the grain because the grain will swell and possibly rupture the bin.
Devices are known for use in large commercial grain elevators, mills, and the like, whereby a controlled amount of moisture is mixed with grain as it passes through a conveyor. See, for example, British Pats. Nos. 226,103; 377,343; and 489,537. These devices, however, are suitable only for large, permanent installations and are not adaptable for use on small to medium sized farms with portable grain augers or elevators.
It has been discovered, however, that, as will be hereinafter described, water may be added at a controlled rate to the hopper of a portable grain auger or elevator, and thereby used to raise the moisture content as the grain is moved from storage. Commercial, portable grain augers or elevators have standard capacities ranging of from, for example, 500 up to 1,500 bushels per hour, depending on the size, or in the case of elevators, the angle and length thereof. Therefore, if water is added at a preselected rate to the hopper, based on the flow rate of the grain from the hopper, the moisture content of the grain will be raised a uniform amount. Furthermore, by matching the flow rate of the water and the capacity of the grain conveying device, it is unnecessary to further calculate the total volume of water needed.
In other words, when the capacity of the auger or elevator is known, a portable device for adding water at a controlled rate may be used without regard to the actual quantity of grain to be moved or the volume of water needed. Once a user determines the percent moisture to be added, the flow rate will be determined and a device according to this invention may be set to delivery the desired rate of flow to the hopper until the grain has been moved from storage, through the hopper and subsequently through the conveyor.
A preferred version of this invention uses a gravity feed to the hopper from a tank having a constant water level therein. Water flows from the tank to the hopper through a narrow or constricted fluid passage in the tank outlet, and the flow rate from the tank, given a constant water level therein, will be determined by the flow characteristics of the passage. The tank may be continually fed from a reservoir with, preferably, a float valve being used to maintain a constant water level therein. The flow controller at the outlet may be merely a flat plate having an axial orifice of a predetermined area. The plate may then merely cover the tank outlet. The size of the orifice in the plate will determine the flow rate, and alternate plates having different sized orifices may be furnished for varying the flow rate from the tank to the hopper depending upon the amount of moisture to be added.
As an alternative to gravity feed, a conventional pump may be provided whereby the pump will deliver the desired constant flow of water to the hopper. Although a variety of different types of pumps may be utilized within the scope of this invention, a motor driven centrifugal pump is preferred for delivering water at a preselected flow rate. The flow rate thereby will be governed primarily by the speed of the impeller. Any well known commercially available pump may be adapted for use herein provided the pump is capable of delivering the desired flow rate of water. In addition, the rate of flow from the pump may be varied as desired by using, for example, a rheostat to control the revolutions per minute of the motor, and therefore the speed of the pump impeller.
Accordingly, it is an object of this invention to provide an inexpensive and efficient, portable device for moisturizing grain.
It is another object of this invention to provide a portable grain moisturizer for use with a portable grain auger or elevator to raise the moisture content of grain being moved thereby a predetermined amount.
It is another object to provide a gravity feed device for delivery of water at a predetermined rate to the hopper of a grain auger or elevator wherein the rate of flow of the water may be easily increased or decreased a predetermined amount.
It is another object to provide a portable grain moisturizer adaptable for use with a wide variety of portable grain augers or elevators whereby water may be added by a gravity flow from a reservoir having a constant water level therein through a flow controller in the reservoir outlet.
It is yet a further object to provide a portable grain moisturizer for use with a wide variety of portable grain augers or elevators whereby water is delivered at a predetermined rate to the hopper thereof by gravity flow from a reservoir through an orifice having a predetermined area.
These and other objects will become readily apparent with reference to the drawings and following description wherein:
FIG. 1 is a side elevation partly in section with parts broken out for the purposes of illustration of an embodiment of this invention;
FIG. 2 is an enlarged fragmentary view of the portion of the device shown in FIG. 1 partly in section;
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a view similar to FIG. 3 of an alternate embodiment thereof; and
FIG. 5 is side elevation partly in section of an alternate embodiment.
With reference to FIG. 1, a gravity feed device 10 for adding water at a predetermined flow rate to the hopper 12 of a conventional grain elevator 14 is shown. The elevator 14 is of conventional design having a linked belt 16 with individual scoops 18 mounted thereon. Belt 16 is mounted in a housing having a bottom 19 and side walls 20. The upper end of elevator 14 is an exit funnel 22. Belt 16 is motor driven by a chain drive or belt drive (not shown), and elevator 14 is supported by braces (not shown) at a desired angle. Grain 24 from hopper 12 is conveyed by belt 26 into the lower end of elevator 14, where it is picked up by scoops 18 conveyed to the upper end of elevator 14, and directed therefrom through exit funnel 22. Hopper 12 normally is disposed with its base 28 at ground level. Sloping side walls 30 are used to funnel grain onto belt 26.
Hopper 12 may be fed by any conventional means such as by hand scooping or by opening the bin and allowing the grain to fall therein.
The preferred version of the device of this invention includes a tank 32 having an inlet 34 and an outlet 36. A constant water level is maintained in tank 32 by, for example, a float valve 38 at the inlet 34. The reservoir 40 containing a large quantity of water may be provided, and a conduit 42 may be used to permit water to flow from the reservoir outlet 44 through the tank inlet 34. Sufficient head pressure should be maintained at outlet 44 to permit the flow of water through conduit 42 and into tank 32 when the float valve 38 is open.
In the alternative, conduit 42 may connect inlet 34 with any conventional source of water under pressure such as a hydrant (not shown). It will be obvious, however, that the valve 38 utilized to control the level of water in tank 32 must be operable to close inlet 34 against the back pressure from reservoir 40.
With attention to FIG. 2, valve 38 includes a valve seat 46 which surrounds inlet 34, and valve element 48 adapted to seat thereon to close inlet 34. Float 50 is connected to element 48 by lever arms 52 and 54 so that as float element 50 rises, lever arm 52, acting through fulcrum 54, and lever arm 56 will force valve element 48 downwardly until it seats on valve seat 46. Similarly, as the water level in tank 32 drops, lever arms 52 and 56 will raise valve element 48 to admit water through conduit 42 into the tank 32.
The rate of flow of water 58 from tank 32 is controlled by an orifice 60 at outlet 36. As is well known, the height of the water in the tank 32 and the area of orifice 60 will dictate the rate of flow through outlet 36 and conduit 62 to hopper 12.
The rate of flow from tank 52 may be varied by utilizing inter-changeable plates 64 shown in FIGS. 3 and 4. Plate 64 is received in recess 66 formed by coupling 68 at outlet 36. Coupling 68 then is utilized both to connect conduit 62 and tank 32, and to retain plate 64 in outlet 36.
FIGS. 3 and 4 illustrate plates 64 and 64' which may alternatively be retained by coupling 68 to provide either orifice 60 or 60' depending upon the rate of flow desired from the tank. As will be understood a variety of plates may be provided having many different sized orifices. Each plate should bear suitable identification to facilitate selection of the desired flow rate.
In order to minimize jet action as water 58 passes through orifice 60, a vent pipe 70 is provided immediately downstream of plate 64. Vent 70 is intended to minimize low pressure turbulence downstream of orifice 60.
In further reference to FIG. 1, conduit 62 may be of any desired length, and may also have a conventional valve 72 to control flow therethrough. It will be obvious to those skilled in the art that valve 72 may be disposed immediately downstream of vent 70, or at the end of conduit 62 as shown in FIG. 1. Depending upon the individual needs, tank 32 and reservoir 40 may be mounted adjacently on a wagon or platform, (not shown), or reservoir 40 may be disposed at a location remote from tank 32. In addition, tank 32 may be disposed over hopper 12 to dispense water directly into grain 24, and in such case conduit 62 need not be present. In addition, conduit 62 should have a larger diameter as compared to that of orifice 60.
It must be emphasized, however, that the length of conduit 62 and valve 72 will influence the flow rate into hopper 12 by fluid friction losses as water passes therethrough. Therefore, if conduit 62 and valve 72 are utilized the size of orifice 60 in plate 64 will have to be larger than if conduit 62 and valve 72 are not used.
However, as will be obvious to those skilled in the art, the area of orifice 60 which will provide the desired flow rate, may be easily calculated by application of Bernoulli's equation. For the purposes of illustration, if frictionless flow is assumed, and orifice 60 has sufficiently sharp edges to neglect the drag created thereby, the kinetic energy of the water exiting orifice 60 will be equal to the potential energy at the water level within tank 32. In other words:
u 2 /2 g = H
wherein: u = the linear velocity in feet per second, g c = the acceleration of gravity in feet per second 2 ; and H = the height of the water level above the orifice in feet. The A of the orifice will then be equal to the mass flow rate q divided by the linear velocity u, or
A = q/u
wherein: q = the mass flow rate in cubic feet per second.
Combining the above equations:
A =q/√2 g H
If a circular orifice is utilized, the diameter D thereof, in inches, will be
D = √ (q/π√2 g H)
If frictionless flow is not assumed then the area will have to be increased to compensate for the friction loss in conduit 62, and valve 72, and the drag created as the stream of water passes through orifice 60 in the well known manner.
With reference to FIG. 5, this invention may be utilized also with a conventional grain auger 74 and its hopper 76. Auger 74 includes a screw conveyor 78 which is driven by a motor (not shown) and disposed within a cylindrical housing 80. The upper end of housing 80 terminates in an exit funnel 82. Grain 24' is dumped into hopper 76 by any conventional method. Screw conveyor 78 then draws the grain into housing 80 at entrance 84 and conveys it therethrough. The grain then exits housing 80 at funnel 82.
FIG. 5 also shows an alternate embodiment wherein a conventional pump 86 is utilized to draw water from a source which may be a reservoir 88, through conduit 90, and feed a controlled rate of flow through conduit 92 to hopper 76. It will be obvious to those skilled in the art that either of the embodiments of this invention shown in FIGS. 1 and 5 may be utilized with either a conventional grain elevator, or a conventional grain auger. This invention is not intended to be limited to the use of a particular type of grain conveyor providing the conveyor moves grain from a hopper.
As will also be obvious to those skilled in the art, in the embodiment of FIG. 5 the head pressure developed by pump 86 will control the flow rate through conduit 92 to hopper 76. Accordingly, in order to establish a constant flow rate, it is preferred to utilize a motor driven centrifugal pump, wherein the motor drives the pump impeller. A rheostat may then be used to control the speed of the motor which in turn will control the flow rate into hopper 76 by causing pump 86 to pump faster or slower depending upon the power input. Pump 86 may be disposed externally to a reservoir 88 as shown in FIG. 5, or if desired, pump 86, but not the motor therefor, may be submerged within the reservoir 88.
The following are examples utilizing the concept of this invention with conventional grain augers or grain elevators.
For the purposes of illustration, the Montgomery Ward Farm Catalog (1972) lists three basic types of grain augers. The 4 inch diameter auger (I) as a capacity of 600 bushels per hour; the 5 inch diameter auger (II) has a capacity of 1,000 bushels per hour, and the 6 inch diameter auger (III) has a capacity of 1,500 bushels per hour. In comparison, Mohawk Portable Auger Scoops manufactured by the Snow Corporation, Omaha, Neb., have a capacity of 600 bushels per hour with the 4 inch diameter auger (IV) and 900 bushels per hour with a 5 inch diameter auger (V). As illustrative of grain elevators, a Montomery Ward portable elevator (VI), when operating at a 35° angle, as stated in the 1972 Farm Catalog, has a capacity of 340 bushels per hour.
Assuming that the grain to be moved weighs 56 lbs. per bushel, and assuming it is desirable to add 3 percent moisture thereto based upon evaluation of the present moisture content, Table I illustrates the mass flow rate of water to the hopper needed to provide the desired increase in moisture content. ------------------------------------------------------------ --------------- TABLE I
Flow Rate - q Conveyor Capacity Flow Rate - q bu/hr. 1bs./hr. lb./hr. ft. 3 /hr. ____________________________________________________________ ______________ I 600 33,600 1008 16.2 II 1000 56,000 1680 27.0 III 1500 84,000 2520 40.4 IV 600 33,600 1008 16.2 V 900 50,400 1512 24.2 VI 340 19,040 571.2 9.2 ____________________________________________________________ ______________
while it is desired to provide the capability for adding from about one to 6 percent moisture, it has been found that three percent will be needed in most instances.
To calculate the orifice size for delivering the desired flow rates, it will be necessary, as above described, to take into consideration the particular type of conduit and valve utilized therein (if any). However, for the purposes of illustration, assuming frictionless flow and a sufficiently short conduit 62 so that the friction head is negligible, and further assuming that the height of the water level H is 4 inches, the diameter D, in inches, of a circular orifice 60 in plate 64 is calculated as follows:
D = 12 √[4q/3600π √ 2 g (1/3)] = 2/5√(q/14.88)
Table II illustrates the diameter D of an orifice of sufficient size as calculated by the above equation to provide the flow rates of Table I to add 3 percent moisture to grain by the above conveyors. ------------------------------------------------------------ --------------- TABLE II
Flow RAte -- q Conveyor (ft 3 /hr) Gallons/hr. Diameter (inches) ____________________________________________________________ ______________ I 16.2 121 0.417 II 27.0 202 0.538 III 40.4 302 0.659 IV 16.2 121 0.417 V 24.2 181 0.511 VI 9.2 688 0.313 ____________________________________________________________ ______________
accordingly, it will be obvious to those skilled in the art that a plurality of interchangeable plates 64 may be provided having apertures for adding, for example, 1-6 percent moisture for a given capacity auger or elevator. Therefore, after determining the percent of moisture to be added, the farmer will merely need to select the plate having an aperture of the correct size, insert it in recess 68, and allow water to drain from tank 32 into the hopper as the grain is being moved from the storage bin to, for example, a truck for transportation to a commercial elevator.
In the event a pump is utilized instead of gravity flow, it is anticipated that the speed of the pump may be varied in order to deliver, when calibrated, the desired flow rate of water from a reservoir corresponding to a predetermined setting of the motor speed.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Following harvest, feed grains are frequently stored for extended periods of time before being moved to a commercial elevator or used for feed. The grain is normally stored in farm bins situated in close proximity to the field or to feed lots, or both. A motor-driven, portable elevator or auger is normally used to move the grain either into a bin or from a bin into a vehicle.
Portable elevators or augers for moving or conveying grain are well known and many types are commercially available. With most such devices the grain is fed into a hopper located on the ground and conveyed by the elevator or auger from the hopper into a bin or a vehicle. A grain auger may be described as a motor driven screw conveyor enclosed within a cylindrical housing. A portable grain elevator, on the other hand, utilizes individual scoops mounted on a linked metal belt disposed within a substantially U-shaped housing. The belt is also motor driven.
Following harvest the grain may be stored on the farm, depending upon the individual farmer's needs, for up to from three to four years. As will be obvious, during storage the grain dries substantially. For example, grain may be harvested with a moisture content, depending on atmospheric conditions, of from 10 to 14 percent or more. However, after storage for 3 or 4 years, this content may fall to 6 percent or less.
If the stored grain is intended for feed, a low moisture content is highly undesirable. Dry grain is less palatable, and therefore less digestable. Accordingly feed grain having a low moisture content will produce a smaller weight gain than grain having a higher moisture content.
More importantly, however, if the grain is intended for sale to a commercial elevator, a low moisture content will lower the farmer's return from the sale. For example, as a general rule the price paid for feed grain by a commercial elevator is based on the actual weight thereof. But, if the grain contains over the maximum specified moisture, a penalty of one cent per bushel for each one quarter percent excess is exacted. However, if the grain has less than the maximum moisture content, a corresponding credit is not allowed, and the sale price is determined by the actual weight at the time of delivery.
Therefore, from an economic standpoint, it is important to market or feed grain having nearly the maximum moisture content. To do so, however, the moisture content must be accurately measured, and then a precise quantity of water must be added to the stored grain at or near the time the grain is to be fed or transported for sale.
Many procedures are known for evaluating the moisture content of a grain sample. For example, the sample may be weighed, heated to drive off the moisture, and then reweighed to establish a dry weight value. The change in weight for the sample divided by the sample weight, multiplied by 100, will be equal to the percent moisture content.
Another well known method for evaluating the moisture content is based on a measurement of the electrical conductivity of the grain sample. This conductivity may then be compared with known values. For example, the measured conductivity of an unknown sample may be used to find its moisture content on a graph plotting moisture content versus conductivity.
Many devices are available commercially for measuring the moisture content according to these and other well known principles.
It will be apparent that when the moisture content and the weight of the grain are known, the latter being determined by the capacity of the bin and the density of the grain, the quantity of water to be added may be easily calculated. However, while the quantity of water to be added may be calculated without difficulty, a satisfactory device for moisturizing stored grain has not been known prior to the instant invention. For example, water may not be sprayed into the bin on top of the grain because the grain will swell and possibly rupture the bin.
Devices are known for use in large commercial grain elevators, mills, and the like, whereby a controlled amount of moisture is mixed with grain as it passes through a conveyor. See, for example, British Pats. Nos. 226,103; 377,343; and 489,537. These devices, however, are suitable only for large, permanent installations and are not adaptable for use on small to medium sized farms with portable grain augers or elevators.
It has been discovered, however, that, as will be hereinafter described, water may be added at a controlled rate to the hopper of a portable grain auger or elevator, and thereby used to raise the moisture content as the grain is moved from storage. Commercial, portable grain augers or elevators have standard capacities ranging of from, for example, 500 up to 1,500 bushels per hour, depending on the size, or in the case of elevators, the angle and length thereof. Therefore, if water is added at a preselected rate to the hopper, based on the flow rate of the grain from the hopper, the moisture content of the grain will be raised a uniform amount. Furthermore, by matching the flow rate of the water and the capacity of the grain conveying device, it is unnecessary to further calculate the total volume of water needed.
In other words, when the capacity of the auger or elevator is known, a portable device for adding water at a controlled rate may be used without regard to the actual quantity of grain to be moved or the volume of water needed. Once a user determines the percent moisture to be added, the flow rate will be determined and a device according to this invention may be set to delivery the desired rate of flow to the hopper until the grain has been moved from storage, through the hopper and subsequently through the conveyor.
A preferred version of this invention uses a gravity feed to the hopper from a tank having a constant water level therein. Water flows from the tank to the hopper through a narrow or constricted fluid passage in the tank outlet, and the flow rate from the tank, given a constant water level therein, will be determined by the flow characteristics of the passage. The tank may be continually fed from a reservoir with, preferably, a float valve being used to maintain a constant water level therein. The flow controller at the outlet may be merely a flat plate having an axial orifice of a predetermined area. The plate may then merely cover the tank outlet. The size of the orifice in the plate will determine the flow rate, and alternate plates having different sized orifices may be furnished for varying the flow rate from the tank to the hopper depending upon the amount of moisture to be added.
As an alternative to gravity feed, a conventional pump may be provided whereby the pump will deliver the desired constant flow of water to the hopper. Although a variety of different types of pumps may be utilized within the scope of this invention, a motor driven centrifugal pump is preferred for delivering water at a preselected flow rate. The flow rate thereby will be governed primarily by the speed of the impeller. Any well known commercially available pump may be adapted for use herein provided the pump is capable of delivering the desired flow rate of water. In addition, the rate of flow from the pump may be varied as desired by using, for example, a rheostat to control the revolutions per minute of the motor, and therefore the speed of the pump impeller.
Accordingly, it is an object of this invention to provide an inexpensive and efficient, portable device for moisturizing grain.
It is another object of this invention to provide a portable grain moisturizer for use with a portable grain auger or elevator to raise the moisture content of grain being moved thereby a predetermined amount.
It is another object to provide a gravity feed device for delivery of water at a predetermined rate to the hopper of a grain auger or elevator wherein the rate of flow of the water may be easily increased or decreased a predetermined amount.
It is another object to provide a portable grain moisturizer adaptable for use with a wide variety of portable grain augers or elevators whereby water may be added by a gravity flow from a reservoir having a constant water level therein through a flow controller in the reservoir outlet.
It is yet a further object to provide a portable grain moisturizer for use with a wide variety of portable grain augers or elevators whereby water is delivered at a predetermined rate to the hopper thereof by gravity flow from a reservoir through an orifice having a predetermined area.
These and other objects will become readily apparent with reference to the drawings and following description wherein:
FIG. 1 is a side elevation partly in section with parts broken out for the purposes of illustration of an embodiment of this invention;
FIG. 2 is an enlarged fragmentary view of the portion of the device shown in FIG. 1 partly in section;
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2;
FIG. 4 is a view similar to FIG. 3 of an alternate embodiment thereof; and
FIG. 5 is side elevation partly in section of an alternate embodiment.
With reference to FIG. 1, a gravity feed device 10 for adding water at a predetermined flow rate to the hopper 12 of a conventional grain elevator 14 is shown. The elevator 14 is of conventional design having a linked belt 16 with individual scoops 18 mounted thereon. Belt 16 is mounted in a housing having a bottom 19 and side walls 20. The upper end of elevator 14 is an exit funnel 22. Belt 16 is motor driven by a chain drive or belt drive (not shown), and elevator 14 is supported by braces (not shown) at a desired angle. Grain 24 from hopper 12 is conveyed by belt 26 into the lower end of elevator 14, where it is picked up by scoops 18 conveyed to the upper end of elevator 14, and directed therefrom through exit funnel 22. Hopper 12 normally is disposed with its base 28 at ground level. Sloping side walls 30 are used to funnel grain onto belt 26.
Hopper 12 may be fed by any conventional means such as by hand scooping or by opening the bin and allowing the grain to fall therein.
The preferred version of the device of this invention includes a tank 32 having an inlet 34 and an outlet 36. A constant water level is maintained in tank 32 by, for example, a float valve 38 at the inlet 34. The reservoir 40 containing a large quantity of water may be provided, and a conduit 42 may be used to permit water to flow from the reservoir outlet 44 through the tank inlet 34. Sufficient head pressure should be maintained at outlet 44 to permit the flow of water through conduit 42 and into tank 32 when the float valve 38 is open.
In the alternative, conduit 42 may connect inlet 34 with any conventional source of water under pressure such as a hydrant (not shown). It will be obvious, however, that the valve 38 utilized to control the level of water in tank 32 must be operable to close inlet 34 against the back pressure from reservoir 40.
With attention to FIG. 2, valve 38 includes a valve seat 46 which surrounds inlet 34, and valve element 48 adapted to seat thereon to close inlet 34. Float 50 is connected to element 48 by lever arms 52 and 54 so that as float element 50 rises, lever arm 52, acting through fulcrum 54, and lever arm 56 will force valve element 48 downwardly until it seats on valve seat 46. Similarly, as the water level in tank 32 drops, lever arms 52 and 56 will raise valve element 48 to admit water through conduit 42 into the tank 32.
The rate of flow of water 58 from tank 32 is controlled by an orifice 60 at outlet 36. As is well known, the height of the water in the tank 32 and the area of orifice 60 will dictate the rate of flow through outlet 36 and conduit 62 to hopper 12.
The rate of flow from tank 52 may be varied by utilizing inter-changeable plates 64 shown in FIGS. 3 and 4. Plate 64 is received in recess 66 formed by coupling 68 at outlet 36. Coupling 68 then is utilized both to connect conduit 62 and tank 32, and to retain plate 64 in outlet 36.
FIGS. 3 and 4 illustrate plates 64 and 64' which may alternatively be retained by coupling 68 to provide either orifice 60 or 60' depending upon the rate of flow desired from the tank. As will be understood a variety of plates may be provided having many different sized orifices. Each plate should bear suitable identification to facilitate selection of the desired flow rate.
In order to minimize jet action as water 58 passes through orifice 60, a vent pipe 70 is provided immediately downstream of plate 64. Vent 70 is intended to minimize low pressure turbulence downstream of orifice 60.
In further reference to FIG. 1, conduit 62 may be of any desired length, and may also have a conventional valve 72 to control flow therethrough. It will be obvious to those skilled in the art that valve 72 may be disposed immediately downstream of vent 70, or at the end of conduit 62 as shown in FIG. 1. Depending upon the individual needs, tank 32 and reservoir 40 may be mounted adjacently on a wagon or platform, (not shown), or reservoir 40 may be disposed at a location remote from tank 32. In addition, tank 32 may be disposed over hopper 12 to dispense water directly into grain 24, and in such case conduit 62 need not be present. In addition, conduit 62 should have a larger diameter as compared to that of orifice 60.
It must be emphasized, however, that the length of conduit 62 and valve 72 will influence the flow rate into hopper 12 by fluid friction losses as water passes therethrough. Therefore, if conduit 62 and valve 72 are utilized the size of orifice 60 in plate 64 will have to be larger than if conduit 62 and valve 72 are not used.
However, as will be obvious to those skilled in the art, the area of orifice 60 which will provide the desired flow rate, may be easily calculated by application of Bernoulli's equation. For the purposes of illustration, if frictionless flow is assumed, and orifice 60 has sufficiently sharp edges to neglect the drag created thereby, the kinetic energy of the water exiting orifice 60 will be equal to the potential energy at the water level within tank 32. In other words:
u 2 /2 g = H
wherein: u = the linear velocity in feet per second, g c = the acceleration of gravity in feet per second 2 ; and H = the height of the water level above the orifice in feet. The A of the orifice will then be equal to the mass flow rate q divided by the linear velocity u, or
A = q/u
wherein: q = the mass flow rate in cubic feet per second.
Combining the above equations:
A =q/√2 g H
If a circular orifice is utilized, the diameter D thereof, in inches, will be
D = √ (q/π√2 g H)
If frictionless flow is not assumed then the area will have to be increased to compensate for the friction loss in conduit 62, and valve 72, and the drag created as the stream of water passes through orifice 60 in the well known manner.
With reference to FIG. 5, this invention may be utilized also with a conventional grain auger 74 and its hopper 76. Auger 74 includes a screw conveyor 78 which is driven by a motor (not shown) and disposed within a cylindrical housing 80. The upper end of housing 80 terminates in an exit funnel 82. Grain 24' is dumped into hopper 76 by any conventional method. Screw conveyor 78 then draws the grain into housing 80 at entrance 84 and conveys it therethrough. The grain then exits housing 80 at funnel 82.
FIG. 5 also shows an alternate embodiment wherein a conventional pump 86 is utilized to draw water from a source which may be a reservoir 88, through conduit 90, and feed a controlled rate of flow through conduit 92 to hopper 76. It will be obvious to those skilled in the art that either of the embodiments of this invention shown in FIGS. 1 and 5 may be utilized with either a conventional grain elevator, or a conventional grain auger. This invention is not intended to be limited to the use of a particular type of grain conveyor providing the conveyor moves grain from a hopper.
As will also be obvious to those skilled in the art, in the embodiment of FIG. 5 the head pressure developed by pump 86 will control the flow rate through conduit 92 to hopper 76. Accordingly, in order to establish a constant flow rate, it is preferred to utilize a motor driven centrifugal pump, wherein the motor drives the pump impeller. A rheostat may then be used to control the speed of the motor which in turn will control the flow rate into hopper 76 by causing pump 86 to pump faster or slower depending upon the power input. Pump 86 may be disposed externally to a reservoir 88 as shown in FIG. 5, or if desired, pump 86, but not the motor therefor, may be submerged within the reservoir 88.
The following are examples utilizing the concept of this invention with conventional grain augers or grain elevators.
For the purposes of illustration, the Montgomery Ward Farm Catalog (1972) lists three basic types of grain augers. The 4 inch diameter auger (I) as a capacity of 600 bushels per hour; the 5 inch diameter auger (II) has a capacity of 1,000 bushels per hour, and the 6 inch diameter auger (III) has a capacity of 1,500 bushels per hour. In comparison, Mohawk Portable Auger Scoops manufactured by the Snow Corporation, Omaha, Neb., have a capacity of 600 bushels per hour with the 4 inch diameter auger (IV) and 900 bushels per hour with a 5 inch diameter auger (V). As illustrative of grain elevators, a Montomery Ward portable elevator (VI), when operating at a 35° angle, as stated in the 1972 Farm Catalog, has a capacity of 340 bushels per hour.
Assuming that the grain to be moved weighs 56 lbs. per bushel, and assuming it is desirable to add 3 percent moisture thereto based upon evaluation of the present moisture content, Table I illustrates the mass flow rate of water to the hopper needed to provide the desired increase in moisture content. ------------------------------------------------------------ --------------- TABLE I
Flow Rate - q Conveyor Capacity Flow Rate - q bu/hr. 1bs./hr. lb./hr. ft. 3 /hr. ____________________________________________________________ ______________ I 600 33,600 1008 16.2 II 1000 56,000 1680 27.0 III 1500 84,000 2520 40.4 IV 600 33,600 1008 16.2 V 900 50,400 1512 24.2 VI 340 19,040 571.2 9.2 ____________________________________________________________ ______________
while it is desired to provide the capability for adding from about one to 6 percent moisture, it has been found that three percent will be needed in most instances.
To calculate the orifice size for delivering the desired flow rates, it will be necessary, as above described, to take into consideration the particular type of conduit and valve utilized therein (if any). However, for the purposes of illustration, assuming frictionless flow and a sufficiently short conduit 62 so that the friction head is negligible, and further assuming that the height of the water level H is 4 inches, the diameter D, in inches, of a circular orifice 60 in plate 64 is calculated as follows:
D = 12 √[4q/3600π √ 2 g (1/3)] = 2/5√(q/14.88)
Table II illustrates the diameter D of an orifice of sufficient size as calculated by the above equation to provide the flow rates of Table I to add 3 percent moisture to grain by the above conveyors. ------------------------------------------------------------ --------------- TABLE II
Flow RAte -- q Conveyor (ft 3 /hr) Gallons/hr. Diameter (inches) ____________________________________________________________ ______________ I 16.2 121 0.417 II 27.0 202 0.538 III 40.4 302 0.659 IV 16.2 121 0.417 V 24.2 181 0.511 VI 9.2 688 0.313 ____________________________________________________________ ______________
accordingly, it will be obvious to those skilled in the art that a plurality of interchangeable plates 64 may be provided having apertures for adding, for example, 1-6 percent moisture for a given capacity auger or elevator. Therefore, after determining the percent of moisture to be added, the farmer will merely need to select the plate having an aperture of the correct size, insert it in recess 68, and allow water to drain from tank 32 into the hopper as the grain is being moved from the storage bin to, for example, a truck for transportation to a commercial elevator.
In the event a pump is utilized instead of gravity flow, it is anticipated that the speed of the pump may be varied in order to deliver, when calibrated, the desired flow rate of water from a reservoir corresponding to a predetermined setting of the motor speed.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.