Drying and gas or vapor contact with solids – Process – Combined
Reexamination Certificate
2000-03-07
2001-05-01
Gravini, Stephen (Department: 3749)
Drying and gas or vapor contact with solids
Process
Combined
C034S467000, C034S495000
Reexamination Certificate
active
06223454
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a method for drying moist organic material, in particular for drying forage crops.
Forage crops and other moist organic materials not harvested for silage are typically dried to obtain a desired moisture level to facilitate storage over extended periods of time. Drying usually occurs naturally outdoors in the field where it is cut and sometimes crimped to aid the drying process. There are several problems with this drying method; (1) natural drying relies on atmospheric temperatures (which are low compared to what can be achieved by artificial means), (2) the relative humidity of the air (which typically varies from a low of 50% to 100% in many areas of the world), (3) movement of the air which can typically vary from 30 mile an hour winds to no wind (and even during relatively high wind conditions the air does not necessarily move rapidly at ground level), and (4) some of the crop is necessarily close to or on the ground where drying occurs slowly because of the moisture coming from below. Though not typical, several methods have been tried to dry forage crops indoors. This always involves transporting a high volume type crop that has a high moisture content thus high mass. Typically two drying methods have been used. One dries by moving atmospheric air (sometimes heated) through the hay placed over open floors until dried. Another method moves the hay through a rotating drum via very hot air blowing through that drum. The latter has achieved energy efficiencies of 1600 to 1700 B T U per pound of water removed. Again, besides the high amount of energy used, the high moisture (thus high mass) forage products need to be hauled considerable distances to achieve a reasonable level of operation for a plant that requires a substantial capital investment.
If the drying process is intended to be used in a timely and efficient connection with harvesting of the organic material, it is imperative that the drying process can be carried out in synchronization with the harvesting. There have been attempts to dry forage crops in the field after cutting such as with the use of microwave heating or squeezing moisture out of the product but all have resulted in low throughput, high energy costs, high equipment cost or loss of product value.
The present invention solves these and other problems associated with existing apparatus and methods for drying moist organic materials.
SUMMARY OF THE INVENTION
The present invention generally relates to a method for drying moist organic material. With the present invention, the organic material is left on the field after cutting, and a drying machine working according to the method of the invention may later take up the material from the ground and dry it. This allows time for partial drying which happens rapidly during the early stages after cutting.
A method for drying a moist organic material which is continuously supplied in a stream includes passing hot air through the moist organic material in a part of the stream to absorb an amount of moisture, whereby the moist organic material cools the hot air into warm air. The warm air is reheated after it exits the moist organic material to form reheated air with increased capability of absorbing moisture, and the reheated air is passed through the moist organic material further upstream, which has a greater moisture content.
An embodiment of the method may be used in drying a mat of a forage crop, such as alfalfa, where the crop has a moisture content of preferably about 15-25% after drying. The drying can preferably be performed in five minutes or less.
A method for drying moist organic material using hot air includes providing the moist organic material in a continuous material stream, and providing the hot air in a continuous air stream. The air stream flows in a direction generally opposite to that of the material stream. The air stream is passed perpendicularly through the material stream at a plurality of zones, whereby the hot air absorbs an amount of moisture from the moist organic material in each zone. The air stream is reheated after it exits the material stream at one zone and before it enters the material stream at another zone further upstream.
An embodiment of the method may be used with a mat of forage crop, such as alfalfa, and the drying is performed using about 3-7 zones.
Advantages arising from using the method of the invention include a more efficient use of the heated air in drying the material. The condition of the air relative to its moisture level can be better monitored, and the drying efficiency and the condition of the finished product can be optimized.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the accompanying drawings and descriptive matter which form a further part hereof, and in which there is illustrated and described a preferred embodiment of the invention.
REFERENCES:
patent: 3760816 (1973-09-01), Wochnowshi
patent: 3829986 (1974-08-01), Ruigrok et al.
patent: 3882611 (1975-05-01), Eykamp
patent: 4045882 (1977-09-01), Buffington et al.
patent: 4050164 (1977-09-01), Campbell
patent: 4101264 (1978-07-01), Barr
patent: 4189848 (1980-02-01), Ko et al.
patent: 4251925 (1981-02-01), Muhsil et al.
patent: 4253825 (1981-03-01), Fasano
patent: 4268971 (1981-05-01), Noyes et al.
patent: 4689894 (1987-09-01), Zeilon
patent: 4912914 (1990-04-01), Wingard
patent: 5105563 (1992-04-01), Fingerson et al.
patent: 5343632 (1994-09-01), Dinh
patent: 5517767 (1996-05-01), Schechinger et al.
patent: 5557859 (1996-09-01), Baron
patent: 5692317 (1997-12-01), Manzolli
patent: 5802734 (1998-09-01), Manzolli
patent: 5836086 (1998-11-01), Elder
patent: 6032384 (2000-03-01), Fingerson et al.
Product Brochure, “Proctor Drying the World's Tobacco”,Proctor&Schwartz, Bulletin 620/R (Apr. 1998).
Product Brochure, “Proctor Conveyor Dryers ° Ovens° Heat Processing Equipment”,Proctor&Schwartz, Bulletin 610/R (Oct. 1997).
Eickhoff Donald W.
Fingerson Conrad F.
Gravini Stephen
Heartland Forage, Inc.
Merchant & Gould P.C.
LandOfFree
Method of drying moist organic material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of drying moist organic material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of drying moist organic material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2530722