US6085440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and an apparatus for producing a powdered product by spin flash drying
Assignee: SPX Flow Technology Danmark AS
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Filing: 1996-11-21
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Granted: 2000-07-11
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Expires: 2016-11-21
Abstract
Abstract A process and an apparatus for drying of a material in the form of a paste or a filter cake in a spin flash dryer. Particles are separated by a classifier (6) in the chamber (1) in such a way that oversize fraction is withheld in the chamber (1) and the desired fraction is removed (3, 9). A possible undesired undersize fraction is strained off and recycled (4, 10, 11) externally back to the dryer chamber (1). The spent drying gas is recycled to the dryer chamber (1). In either, the energy in the spent drying gas may be made use of in a heat exchanger and there is no or only little emission to the environment. Products preferably dried according to the invention are fruit and beet pulps, destillers residues, pesticides, pigments, dyes, ceramics, active coal, sludge and zeolites.
Inventors
- 👤 Jens Getler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:46
CPC Classifications
F; F26; F26B; F26B17/00; F26B17/10; F26B17/107; F26B17/101; F26B17/102; F26B3/00; F26B3/02; F26B3/06; F26B3/08; F26B3/092; F26B3/0923
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
150 words
A process for producing a powder by spin flash drying, thereby drying a paste or a filter cake comprising the steps of, feeding the material to be dried to a dryer chamber (1), contacting said material with a stream of drying gas to obtain dry particles, adjusting the amount of introduced material with the amount and drying capacity of introduced drying gas thereby controlling to a desired moisture content and size of the particles leaving the dryer chamber (1), subjecting said particles to a size classification into at least two fractions in a classifier (6), which first fraction comprises particles with the predetermined particle size distribution, which is withdrawn as product, suspended in a first exit gas stream, and which second undersize fraction is withdrawn from the classifier (6) as an entrained suspension in a second exit gas stream and is returned to the dryer chamber (1) as solid particles.
Claim 2
Dependent Claim
150 words
A process for producing a powder by spin flash drying, thereby drying a paste or a filter cake comprising the steps of, feeding the material to be dried to a dryer chamber (1), contacting said material with a stream of drying gas to obtain dry particles, adjusting the amount of introduced material with the amount and drying capacity of introduced drying gas thereby controlling to a desired moisture content and size of the particles leaving the dryer chamber (1), subjecting said particles to a size classification into at least two fractions in a classifier (6), which first fraction comprises particles with the predetermined particle size distribution, which is withdrawn as product, suspended in a first exit gas stream, and which second undersize fraction is withdrawn from the classifier (6) as an entrained suspension in a second exit gas stream and is returned to the dryer chamber (1) as solid particles.
Claim 3
Dependent Claim
47 words
The process according to claim 1, comprising the step of collecting the gas of the first and second exit gas streams from the classifier (6) after separation of the particles from the gas streams, and returning the collected gas as drying gas to the dryer chamber (1).
Claim 4
Dependent Claim
16 words
The process according to claim 1, wherein the recycled drying gas is reheated by indirect heating.
Claim 5
Dependent Claim
16 words
The process according to claim 1, wherein the recycled drying gas is reheated by direct heating.
Claim 6
Dependent Claim
39 words
The process according to claims 1 and 4, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.4 kg water pr kg dry drying air or higher.
Claim 7
Independent Claim
105 words
An apparatus comprising, a spin flash dryer with a vertical, cylindrical dryer chamber (1), having a rotating coaxial placed stirrer, with a variable speed drive screw feeder (5) and with apertures (2) for supply of hot drying gas and for the removal of the spent drying gas and removal of the dried material, a first classifier means (7) in the upper part of the dryer chamber (1), a second classifier means (8) in the upper part of the dryer chamber (1), means (9) for separating suspended desired particles from drying gas, means (10, 11) for separating and recycling undersize particles to the dryer chamber (1).
Claim 8
Independent Claim
105 words
An apparatus comprising, a spin flash dryer with a vertical, cylindrical dryer chamber (1), having a rotating coaxial placed stirrer, with a variable speed drive screw feeder (5) and with apertures (2) for supply of hot drying gas and for the removal of the spent drying gas and removal of the dried material, a first classifier means (7) in the upper part of the dryer chamber (1), a second classifier means (8) in the upper part of the dryer chamber (1), means (9) for separating suspended desired particles from drying gas, means (10, 11) for separating and recycling undersize particles to the dryer chamber (1).
Claim 9
Dependent Claim
21 words
Apparatus according to claim 6, wherein each of the first and second classifier means comprises a central annular orifice (7, 8).
Claim 10
Dependent Claim
33 words
Apparatus according to claim 6, wherein the distance between the annular orifices of the first and the second classifier means (7,8) is 0.1 to 1 times, the diameter of the dryer chamber (1).
Claim 11
Dependent Claim
47 words
Apparatus according to claim 6, wherein the diameter of the lower annular orifice (7) is 0.1 to 0.95 times the diameter of the dryer chamber (1), and the diameter of the upper annular orifice (8) is 0.05 to 0.9 times the diameter of the dryer chamber (1).
Claim 12
Dependent Claim
16 words
Apparatus according to claim 6, wherein the orifices of the classifier means (7, 8) are adjustable.
Claim 13
Dependent Claim
45 words
Apparatus according to claim 6, comprising means (12)for collecting streams of exit drying gas, means (13) for separating drying gas into an excess stream, which is led to a cooler (14) and a stream which is recycled as drying gas to the dryer chamber (1).
Claim 14
Dependent Claim
16 words
Apparatus according to claim 11, wherein means (16) to reheat the recycled drying gas are provided.
Claim 15
Dependent Claim
37 words
A process according to claim 2, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.4 kg water pr kg dry drying air or higher.
Claim 16
Dependent Claim
37 words
A process according to claim 3, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.4 kg water pr kg dry drying air or higher.
Claim 17
Dependent Claim
37 words
A process according to claim 4, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.4 kg water pr kg dry drying air or higher.
Claim 18
Dependent Claim
22 words
The process according to claim 5, wherein the moisture content in the drying gas is 0.6 kg/kg dry drying air or higher.
Claim 19
Dependent Claim
32 words
Apparatus according to claim 8, wherein the distance between the annular orifices of the first and second classifier means (7,8) is 0.2 to 0.5 times the diameter of the dryer chamber (1).
Claim 20
Dependent Claim
43 words
Apparatus according to claim 9, wherein the diameter of the lower annular orifice (7) is 0.5 to 0.95 times the diameter of the dryer chamber (1), and upper annular orifice (8) is 0.45 to 0.9 times the diameter of the dryer chamber (1).
Claim 21
Dependent Claim
37 words
A process according to claim 2, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.6 kg water pr kg dry drying air or higher.
Claim 22
Dependent Claim
37 words
A process according to claim 3, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.6 kg water pr kg dry drying air or higher.
Claim 23
Dependent Claim
37 words
A process according to claim 4, wherein the excess of drying gas is controlled in such a way that the moisture content in the drying gas is 0.6 kg water pr kg dry drying air or higher.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-07-11 | 2004-01-10 | 2004-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-11 | 2008-01-10 | 2008-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-11 | 2012-01-10 | 2012-07-11 | $7700.00 | Window Closed / Lapsed |