Self regulating grain bin wall air system and method

• US 4,885,985 A
• Filed: 03/21/1988
• Issued: 12/12/1989
• Est. Priority Date: 03/21/1988
• Status: Expired due to Fees

• Current Assignee: Grain Systems, Inc.
• Original Assignee: Grain Systems, Inc.
• Inventors: Pollock, Eugene B.
• Primary Examiner(s): Bennet, Henry A.
• Application Number:
  US07/170,902
• Time in Patent Office: 631 Days
• Field of Search: 34/232, 34/233, 34/235, 34/209, 98/55
• US Class Current: 454/182
• CPC Class Codes: A23B 9/08 Drying; Subsequent reconstitution
• CPC Class Codes: B65D 88/742 using ventilating sheaths
• CPC Class Codes: F26B 21/12 Velocity of flow; Quantity of flow , e.g. by varying fan speed, by modifying cross flow area F26B21/004 takes precedence; changing air flow pattern F26B21/022
• CPC Class Codes: F26B 9/063 for drying granular material in bulk, e.g. grain bins or silos with false floor shallow layer rotary sweep drying bins F26B9/10; perforated wall silos with drying air channels in the stack F26B9/103

Abstract

A grain drying system around the interior of a grain bin wall which dries grain adjacent the bin wall while minimizing air and heat loss above the level of grain stored in a bin is disclosed. The system is self-regulating and limits air flow to areas above the level of the grain in response to changes in grain level or air pressure in the system. In the grain drying system, vertical air passageways or tubes extend about the interior of the bin wall. The elongated passageways, which have air diffusing or outlet areas, are arranged in fluid communication with a plenum chamber below an air permeable grain supporting subfloor in the grain bin. Each of the passageways or tubes has a movable float slidable therein. When pressure in the plenum chamber reaches a pressure equal to or greater than a predetermined level at which the floats are calculated to operate, the floats then rise within the air passageways until equilibrium with grain created air resistance is reached. Of course, the grain created air resistance is dependant on the level or depth of the grain in the bin above the sub-floor. The air floats automatically and substantially block or the limit air flow above the level of the grain in the grain bin, and a more efficient operating aeration and drying system is provided without unnecessary air and heat loss. In addition to the aforementioned system, a method of drying grain around the interior of a grain bin wall while minimizing air and heat loss above the level of grain stored in the bin is also disclosed.

Claims

1. In a grain bin having a bin wall supported on said foundation floor, a plurality of generally vertically extending, elongated air passageways within said bin, each of said air passageways having a plurality of air outlets which direct air flow from the air passageways generally into the grain along the length of the air passageway, and means for introducing air into said air passageway, and means for introducing air into said air passageways for discharge from said spaced outlets thereby to dry grain in proximity to said air passageways, the improvement comprising:

means for automatically limiting the air flow through said air outlets in said air passageways above the level of the grain in the grain bin in response to changes in the level of the grain in said grain bin, said air loss reduction means associated with each of said air passageways comprising air float means in each of said air passageways to limit air flow to those outlets in said air passageways above the grain level in response to pressure changes within said air passageways.

2. The improvement as defined in claim 1 wherein said grain bin further has a foundation floor and an air permeable sub-floor spaced above said foundation floor thereby defining a plenum chamber therebetween, said air introduction means being in communication with said plenum chamber thereby to force air through said permeable sub-floor and into said air passageways, said air float means rising or falling within their respective said air passageways until they reach equilibrium with grain created air resistance pressure in said plenum chamber.

3. The improvement as defined in claim 2 wherein each said air float means has an end section which extends transverse to its said air passageway and against which air pressure is directed.

4. The improvement as defined in claim 3 wherein the air float means has an outer shape which is configured and dimensioned relative to said air passageway to permit non-binding movement thereof within said air passageway in response to change in pressure in said plenum chamber.

5. The improvement as defined in claim 4 wherein each said air passageway is provided in a respective hollow conduit member having a generally triangular cross section, and the outer shape of said air float means has a corresponding triangular cross section to provide self-aligned guiding movement within its said hollow conduit member.

6. The improvement as defined in claim 5 wherein said spaced outlets in said air passageways comprise spaced air diffusing perforations formed in said hollow conduit members.

7. The improvement as defined in claim 6 including means for limiting lower travel of the float means within said conduit members.

8. A grain drying system for grain bins having a foundation floor, a bin wall supported on said foundation floor, an air permeable grain supported sub-floor spaced from the foundation floor and defining therebetween a plenum chamber, said sub-floor and bin wall containing grain to be dried, a plurality of generally vertically extending, elongated air passageways positioned within said grain and being in fluid communication with air from within the plenum chamber, each of said air passageways having a plurality of spaced outlet areas which direct air flow from the air passageways into said grain, means for introducing air under pressure into said plenum chamber and through said air permeable sub-floor and into said air passageways, and means operatively associated with said air passageways for automatically limiting the air flow through those outlet areas in said air passageways which extend above the level of grain in the grain bin in response to changes in the level of the grain in the bin, whereby air loss through those outlet areas above the grain in the grain bin is minimized.

9. A method of drying or conditioning grain in a grain bin, the latter being supported on a foundation floor and having a generally cylindric bin wall extending upwardly from said foundation floor, said bin having a plenum chamber, a heater/fan assembly for introducing heated air under pressure into said plenum chamber, a plurality of air passageways extending generally vertically at spaced intervals within said bin, said air passageways bring in fluid communication with said plenum chamber and having a plurality of spaced outlets therealong for discharging air from said plenum chamber into said grain, wherein the method comprises the steps of:

Providing air float means in each of said air passageways which is slidably, sealably movable within its said air passageway; and

Selecting the weight and cross-sectional areas of each said air float means such that said air float means rise and fall within said air passageways to equalibrium positions within said air passageways corresponding generally to the level of the grain in said bin, said air float means substantially blocking the flow of air through said passageways above the level of said grain.

10. A method of drying or conditioning grain in a grain bin while minimizing air loss above the level of the grain in the bin, said bin having a plurality of generally vertically extending air passageways within said bin, each said air passageways being at least in part within said grain, said air passageways having a plurality of air discharge openings therealong, said method comprising the steps of:

introducing air under pressure into said air passageways such that the air is discharged from said air discharge openings into the grain along the length of said air passageways;

varying the pressure of the air introduced into said air passageways in response to changes in the level of the grain in the grain bin; and

automatically limiting the air flow through said air discharge openings above the level of the grain in the grain bin in response to changes in the level of the grain in the grain bin.