This application relates to the depositing of granular materials by a pneumatic conveyor into a storage silo.
Pneumatic conveyor systems have become a popular alternative to augers and belted conveyors for the movement of granular materials. Pneumatic systems are especially suitable for farm grains for the following reasons:
a) Grain is carried within a stream of air for less grain damage.
b) A pneumatic delivery system is more economical to install.
c) A pneumatic system is more versatile for multiple silos and multiple silo types at a storage facility.
d) Pneumatic systems are sealed against water and pest infiltration between receiving point to drop point of the grain.
e) One pneumatic system can be utilized to move a variety of grain types without cross contamination, simply by turning a valve distributor between silos.
f) Pneumatic systems are easier to maintain.
Problems associated with the present art of grain delivery to the top of a storage silo are many.
a) An expensive cyclone is required for the top of each silo.
b) The entire system is exterior of the silo, exposing the machinery to weather related damage.
c) Expensive hardware must be used to support the pneumatic tubing system.
d) Much of the installation is high above ground and not easily serviced.
e) Unnecessary grain to grain damage occurs due to the falling of grain from the silo top to the silo floor. This percentage (%) of grain damage increases with the height of the silo.
f) Mixed granular materials experience product separation when dropped into the top of a silo.
g) An efficiency loss of approximately ten percent (10%) for every twenty-five (25) feet of vertical rise is common to all pneumatic delivery systems. For example: a pneumatic system used to fill a silo 100 feet tall would operate at 40% less than full capacity (100÷25×10%=40%).
U.S. Pat. No. 6,632,063 B1 Karlsen et al. Oct. 14, 2003, describes an elaborate and expensive system for the reduction of material separation from a top filled silo.
U.S. Pat. No. 4,603,769 to Bach et al. Aug. 5, 1986, depicts an elaborate chute system for reducing grain damage and separation. This system requires a top filled silo.
U.S. Pat. No. 4,082,364 to Krambrock Apr. 14, 1978, discloses a method for sequential filling that is impractical to a single unsealed silo.
The article Pneumatic Conveying Systems course No. M 05-010 by A. Bhatia @ CEDengineering.com discusses the technical aspects of the present art. Bhatia describes possible problems related to pneumatic conveyors. On page 17 and 18 of 57 the author discusses “choking” as a problem related to a pneumatic tubing installed vertically. A choking condition occurs when the granular material settles out of the airstream and falls downward.
In accordance with one embodiment a method for the depositing of granular material within a storage silo having a means of supporting an internal structure, a means of separating air from material for a pneumatic system, and a method for sequential filling of said silo.
The present application has many advantages to be added to the present art of pneumatic delivery systems.
a) The elimination of roof top delivery removes a major source of contamination.
b) The extra expense associated to machinery for roof top delivery is eliminated.
c) The reduced drop height associated with sequential delivery greatly reduces grain to grain impact and material separation.
d) The reduction in average drop height of material also increases efficiency of this pneumatic system. Typically a 10% reduction of flow is calculated for each 25 feet of vertical rise. A 100 foot silo of previous design would have a 40% loss of efficiency (100÷25×10=40%).
The calculated loss for the present invention would be 25% for a system having four (4) separators ((10%+20%+30%+40%)÷4)=25%). This is a 15% increase of delivery efficiency.
e) Pneumatic tube routing to the silo is done at ground level for easier maintenance of horizontal pneumatic tubing connected to the silo.
f) The delivery system is protected from weather deterioration and requires no maintenance.
g) Another advantage is simplicity of operation.
h) No moving parts are required.
i) Separators act independently and automatically.
One embodiment of present invention is shown within a vertical storage silo 8 in
A conventional pneumatic charging system is shown generally as conveyor 7. Conveyor 7 conducts to tube 14. Tube 14 is a pneumatic transfer tube of prior art. Horizontal tube 114 enters silo 8 through lower portion of silo wall 13. Elbow 12 directs tube 114 into the vertical center of said silo 8 continuing as tube 214 slips into separator 108. Separator 108 transmits upward through tube 314 slips into separator 208. Separator 208 connects to tube 414 to top separator 308.
Tube 14 is suspended and centered within silo 8 from silo wall 13 by a series of clamp assembly 15a,b,c and d.
Clamp assembly 15a is positioned near bottom of vertical rise of tube 214.
Clamp assembly 15b is positioned below separator 108 near top of tube 214.
Clamp assembly 15c is positioned below separator 208 near top of tube 314. Clamp assembly 15d is positioned on 414.
Clamp assembly 15d is typical of clamp assemblies 15. Clamp assembly 15d is shown as: clamp 16d attached through brace 10a and 10c to respective wall bracket 11a and 11c. Wall brackets 11a and 11c are attached to the inner surface of silo wall 13. Brace 10 is a metal rod or cable having 2 end holes. Brace 10 has a length equal to or grater than radius of silo 8.
Clamp assembly 15 of
Clamp 16 is a subassembly of clamp assembly 15. Clamp 16 has an inside circumference less than the outside circumference of tube 214. Clamp 16 is composed of metal plate or metal casting. Clamp 16 is an union of two equal half clamps 17a and 17b. Half clamp 17a has outward radiating end flange 215a or 215c on each end. Half clamp 17a has one or more brackets 415d evenly spaced between half clamp 17a ends. Bracket 415d has two flanges closely spaced, and parallel. Bracket 415d has one aligning through hole shared with adjacent flanges. Bracket 415a is formed by flange 215a of half clamp 17a and flange 215a′ of half clamp 17b.
A wall bracket 11 is metal or metal casting fixture. Each wall bracket 11 has a base and 2 parallel wall bracket flanges. Wall bracket flanges share a common aligning through hole. The base of wall bracket 11 has two or more holes.
Wall brackets 211a,b,c, and d are evenly spaced on a horizontal plane of inner surface of silo 13. Each wall bracket 11 is above the vertical height of clamp 16. Each wall position 213a,b,c,d aligns with a corresponding wall bracket 211a,b,c,d. Each wall bracket 11 is mechanically fastened or bolted to silo 8 through silo wall 13.
Wall brackets 211a,b,c, and d of
Each clamp bracket 415 and d is connected to silo wall 13 equally. Clamp bracket 415 receives and retains one open end of brace 10 with a bolt. Wall bracket 11 receives and retains second open end of brace 10 with a bolt or fastener. Each bracket 415 is secured to each brace 10 by a mechanical fastener or bolt 615. Each brace 210a,b,c, and d radiates outward and upward from respective bracket 415a,b,c,and d. Each open end of brace 210a,b,c, and d is inserted into corresponding wall bracket 211a,b,c, and d. Brace 10 is secured to wall bracket 11 by fastener or bolt 615.
One embodiment of a material separator 108 is shown in
Separator base 408 continues upward and inward to outlet 412 creating forcing cone 419. Outlet 412 has the same outside diameter as tube 214. The overall height of a separator 108 is approximately six (6) times the diameter of inlet 317.
One embodiment of a top separator 308 is shown in
Top separator wall 519 is a continuation of top base 508. Said wall 519 slopes inward and upward to a diameter two (2) times diameter of said inlet 414 creating an expanded area. The overall height of top separator 308 is six (6) times the diameter of said top separator inlet 414. Top 513 of top separator 308 is mushroom shaped. The stem of top 513 is centered into top outlet 512. Top 513 is connected to upper portion of top separator wall 519 by a plurality of web members 607a,b,c, and d.
A material separator system of the present art uses the same pneumatic transfer machines and tubing as prior art. Typically a blower supplies air flow to a rotary airlock. The rotary airlock entrains material into the airstream creating a pneumatic fluid propelled mixture. This process is shown as conveyor 7 in
For a storage silo having a material level 9, tube 14 receives pneumatic propelled material into storage silo 8 through lower portion of silo wall 13. Pneumatic material flow 24 is propelled horizontally through tube 114 to elbow 12. Elbow 12 directs pneumatic material flow 24 upward into vertical center of the storage silo 8.
Pneumatic tube 214 transmits pneumatic material flow 24 downstream. Selectively closed separator 108 directs material flow 24 into tube 314 to separator 208. Separator 208 provides a means for the choking separation of entrained material from the conducting fluid flow. Pneumatically propelled material 24 expands into the increased diametric volume of separator 208. Air flow 134 is rapidly released through separator outlet 412 and also downward through open bottom 418 as illustrated in
Insufficient air pressure results in a choking action, depositing material 124 by gravity through open bottom 418. Falling material 124 raises level of grain mound 9 to meet open bottom 418 of separator 208. Material 124 blocks open bottom 418 blocking material flow 24 release through open bottom 418.
Pneumatic material flow 24 is reestablished upstream to top separator 308. The operation of top separator 308 is similar to that of separator 208 and 108. Top 513 inserted into top separator outlet 512 redirects pneumatic material flow 24 downward into the storage silo.
Thus, for each separator, the separator functions selectively in either one of two modes of operation. In one mode of operation, the separator separates the granular material from the airstream entraining the granular material. In another mode of operation, the airstream entraining the granular material flows through the separator without separating. The selection between the two modes of operation is automatic, based on whether the surface of the grain mound does or does not block the outlet of the separator for depositing the granular material onto the grain mound, and requires no moving parts. Thus, the separator selectively separates the granular material to sequentially fill the silo up to the height that that separator is located within the silo.
A method for the suspension and centering of a pneumatic tube 14 is provided by a plurality of clamp assemblies 15a,b,c and d. Each clamp assembly 15 is structurally attached to the silo wall 13 through a plurality of brackets to distribute pressure. The distribution of wall brackets 11 throughout the silo provides even weight transfer to the silo walls.
The two equal halves of clamp 16 simplifies construction. Clamp 16 provides for even load transfer and stabilization through the application of opposing clamp brackets 415.
Suspension of an internal pneumatic system provides an unobstructed floor area for mechanical sweeping.
It is also possible to charge the system of the present art through the silo floor as an alternative to through the wall delivery.
The present disclosure is not intended to be limited to only metal materials. Plastic and rubber may also be substituted for any or all parts.
Another advantage is the simplicity of operation. No moving parts are required. The separators act independently and automatically. The separators deposit material sequentially along on the downstream flow from the lowest position to the top of the storage silo.
Although the preceding specifications are primarily for grain, claims and intent should be construed to include all manner of granular material. Pelletized food products, fuels, coal, animal feeds, plastics, and fiber products are a few of the other items suitable for pneumatic transfer for storage. The present disclosure also lends itself to colorful displays including confectionaries through the use of clear glass or clear plastic materials.
This application claims benefit of U.S. Provisional Application No. 61/850,770 filed Feb. 23, 2013 which is incorporated by reference.
Number | Date | Country | |
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61850770 | Feb 2013 | US |