Patent US3735792A successfully refreshed from Google Patents.
US3735792A
Expired / Lapsed
US
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Spray drying method and apparatus for producing granular particles from stock liquids of solids
Assignee: Asizawa Tekko KK
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Filing: 1971-03-04
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Granted: 1973-05-29
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Expires: 1991-03-04
Abstract
Abstract A spray drying method comprising forming a layer of solid particles at the bottom of a drying chamber defined by a vertical cylinder, blowing gas into said layer from the underside to agitate the whole of said layer and thereby to form a fluidized bed of solid particles with part of said particles being blown up from the upper surface of said fluidized bed and suspended within said drying chamber, blowing gas into said drying chamber in a direction to form a swirling downward gas flow along the side wall and a swirling upward flow along the center of said drying chamber, whereby said suspending particles are caused to make a circulatory motion while being entrained in said swirling gas flows in such a manner that the fine particles spirally move upward in the center of the drying chamber and at least the major part thereof approach the side wall of the drying chamber under the effect of centrifugal force before they reach the top of said drying chamber and finally spirally move downward along the side wall of said chamber, said particles being partially returned to said fluidized bed and partially being carried upward again in the center of the drying chamber by being entrained in said swirling upward gas flow, spraying stock solution into said drying chamber, the droplets of said sprayed stock solution colliding against and adhered to said circulating particles to form larger sized particles, said larger sized particles being dried by the surrounding gas and partially circulated within said drying chamber and partially falling into said fluidized bed, and discharging said larger sized particles from said fluidized bed while maintaining the depth of said fluidized bed substantially constant.
Inventors
- 👤 N Asizawa
- 👤 M Kono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:56
CPC Classifications
C; C13; C13B; C13B30/00; C13B30/02; C13B30/028; A; A23; A23P; A23P10/00; A23P10/20; B; B01; B01D; B01D1/00; B01D1/16; B01D1/18; B01J; B01J2/00; B01J2/003; B01J2/16; F; F26; F26B; F26B3/00; F26B3/02; F26B3/06; F26B3/08; F26B3/092; F26B3/0926; Y; Y10; Y10S; Y10S159/00; Y10S159/03
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
283 words
A spray drying method comprising forming a layer of solid particles at the bottom of a drying chamber defined by a vertical cylinder, blowing gas into said layer from the underside to agitate the whole of said layer and thereby to form a fluidized bed of solid particles with part of said particles being blown up from the upper surface of said fluidized bed and suspended within said drying chamber, blowing gas into said drying chamber in a direction to form a swirling downward gas flow along the side wall and a swirling upward flow along the center of said drying chamber, whereby said suspending particles are caused to make a circulatory motion while being entrained in said swirling gas flows in such a manner that the fine particles spirally move upward in the center of the drying chamber and at least the major part thereof approach the side wall of the drying chamber under the effect of centrifugal force before they reach the top of said drying chamber and finally spirally move downward along the side wall of said chamber, said particles being partially returned to said fluidized bed and partially being carried upward again in the center of the drying chamber by being entrained in said swirling upward gas flow, spraying stock solution into said drying chamber, the droplets of said sprayed stock solution colliding against and adhered to said circulating particles to form larger sized particles, said larger sized particles being dried by the surrounding gas and partially circulated within said drying chamber and partially falling into said fluidized bed, and discharging said larger sized particles from said fluidized bed while maintaining the depth of said fluidized bed substantially constant.
Claim 2
Dependent Claim
283 words
A spray drying method comprising forming a layer of solid particles at the bottom of a drying chamber defined by a vertical cylinder, blowing gas into said layer from the underside to agitate the whole of said layer and thereby to form a fluidized bed of solid particles with part of said particles being blown up from the upper surface of said fluidized bed and suspended within said drying chamber, blowing gas into said drying chamber in a direction to form a swirling downward gas flow along the side wall and a swirling upward flow along the center of said drying chamber, whereby said suspending particles are caused to make a circulatory motion while being entrained in said swirling gas flows in such a manner that the fine particles spirally move upward in the center of the drying chamber and at least the major part thereof approach the side wall of the drying chamber under the effect of centrifugal force before they reach the top of said drying chamber and finally spirally move downward along the side wall of said chamber, said particles being partially returned to said fluidized bed and partially being carried upward again in the center of the drying chamber by being entrained in said swirling upward gas flow, spraying stock solution into said drying chamber, the droplets of said sprayed stock solution colliding against and adhered to said circulating particles to form larger sized particles, said larger sized particles being dried by the surrounding gas and partially circulated within said drying chamber and partially falling into said fluidized bed, and discharging said larger sized particles from said fluidized bed while maintaining the depth of said fluidized bed substantially constant.
Claim 3
Dependent Claim
72 words
A spray drying method according to claim 1, wherein said gas is introduced into said drying chamber from product particle discharge port means provided at the bottom of said drying chamber and those of said larger sized particles which have grown to a predetermined size and larger are discharged under gravity through said discharge port means against the flow of said gas, whereby the particles of the predetermined size are selectively obtained.
Claim 4
Dependent Claim
34 words
A spray drying method according to claim 1, wherein said drying chamber has a double wall structure and a heat transfer medium is circulated through the interspace between the inner wall and outer wall.
Claim 5
Dependent Claim
29 words
A method in accordance with claim 1 in which the gas is introduced into the drying chamber in the direction substantially tangential to the side wall of said chamber.
Claim 6
Dependent Claim
32 words
A method in accordance with claim 1 in which said swirling upward flow along the center of said drying chamber is passed through separating means to centrifugally separate the particles suspended therein.
Claim 7
Dependent Claim
106 words
A spray drying apparatus comprising a vertical cylinder defining a drying chamber, gas inlet port means provided at the upper portion of said drying chamber to form swirling downward gas flow, gas outlet port means provided at the center of the upper end of said drying chamber for exhausting an ascending gas flow therethrough, perforated plate means disposed at the bottom of said drying chamber, means for blowing air into said drying chamber from the underside through said perforated plate, means for spraying stock solution into said drying chamber, and means for discharging solid particles from a solid particle layer formed on said perforated plate means.
Claim 8
Dependent Claim
106 words
A spray drying apparatus comprising a vertical cylinder defining a drying chamber, gas inlet port means provided at the upper portion of said drying chamber to form swirling downward gas flow, gas outlet port means provided at the center of the upper end of said drying chamber for exhausting an ascending gas flow therethrough, perforated plate means disposed at the bottom of said drying chamber, means for blowing air into said drying chamber from the underside through said perforated plate, means for spraying stock solution into said drying chamber, and means for discharging solid particles from a solid particle layer formed on said perforated plate means.
Claim 9
Dependent Claim
56 words
A spray drying apparatus according to claim 6, wherein said discharge means includes at least one product discharge conduit extending upwardly towards the bottom of said drying chamber with the upper end opening at said perforated plate, and is provided with means for regulating gas flow being introduced into the drying chamber through said discharge conduit.
Claim 10
Dependent Claim
62 words
A spray drying apparatus according to claim 6, wherein means is provided at the top portion of said drying chamber for separating the solid particles by the effect of centrifugal force from the gas flowing upwardly from said drying chamber and part of swirling gas flow within said separating means is led into the drying chamber to form swirling downward gas flow.
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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) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |