US3675600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recirculating dryer system
Assignee: Individual
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Filing: 1971-01-21
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Granted: 1972-07-11
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Expires: 1991-01-21
Abstract
Abstract Combustion gases from a waste wood fired furnace are circulated through a wood veneer dryer or lumber dry kiln and returned to a mixing chamber for exposure to the hot gases leaving the furnace, causing incineration of volatile hydrocarbons and wood fiber picked up by the gas stream in its passage over the veneer or lumber. The only exhaust from the system is located between the outlet from the high temperature mixing chamber and the gas inlet to the dryer. This arrangement insures the incineration of all combustibles before they are vented to atmosphere or returned to the dryer so that no pollutants are discharged into the atmosphere and no potentially explosive substances are passed into the dryer.
Inventors
- 👤 Allen J Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:18
CPC Classifications
F; F23; F23G; F23G5/00; F23G5/08; F23G5/14; F23G5/16; F23G7/00; F26; F26B; F26B23/00; F26B23/02; F26B23/022; F26B2210/00; F26B2210/14; F26B2210/16
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
124 words
A recirculating dryer system comprising a furnace having a combustion chamber, a first fan supplying primary air from outside atmosphere to said combustion chamber, a second fan having an inlet duct receiving hot combustion gases from said combustion chamber and having a discharge duct conveying said combustion gases to a dryer, a return duct conveying said combustion gases out of said dryer together with combustible substances from material being dried in said dryer, said return duct discharging into said hot combustion gases on the inlet side of said second fan causing said combustible substances from the material being dried to be incinerated, and an exhaust stack branching from said discharge duct to vent a portion of the gases in said discharge duct to atmosphere.
Claim 2
Dependent Claim
124 words
A recirculating dryer system comprising a furnace having a combustion chamber, a first fan supplying primary air from outside atmosphere to said combustion chamber, a second fan having an inlet duct receiving hot combustion gases from said combustion chamber and having a discharge duct conveying said combustion gases to a dryer, a return duct conveying said combustion gases out of said dryer together with combustible substances from material being dried in said dryer, said return duct discharging into said hot combustion gases on the inlet side of said second fan causing said combustible substances from the material being dried to be incinerated, and an exhaust stack branching from said discharge duct to vent a portion of the gases in said discharge duct to atmosphere.
Claim 3
Dependent Claim
32 words
A system as defined in claim 1 including heat exchange means arranged to heat said gases and combustible substances from said return duct before they are discharged into said hot combustion gases.
Claim 4
Dependent Claim
31 words
A system as defined in claim 2, said heat exchange means comprising a jacket around at least a portion of said combustion chamber and said inlet duct to said second fan.
Claim 5
Dependent Claim
16 words
A system as defined in claim 1 including heat exchange means for heating said primary air.
Claim 6
Dependent Claim
19 words
A system as defined in claim 4, said heat exchange means comprising a heat exchanger in said exhaust stack.
Claim 7
Dependent Claim
21 words
A system as defined in claim 4, said heat exchange means comprising a jacket around a portion of said combustion chamber.
Claim 8
Dependent Claim
44 words
A system as defined in claim 1 including a damper between said combustion chamber and said inlet duct for said second fan, said return duct from the dryer discharging into said inlet duct for said second fan on the downstream side of said damper.
Claim 9
Dependent Claim
43 words
A system as defined in claim 1, said combustion chamber having walls causing said combustion gases to flow first upward, then downward, then again upward, and a refractory damper in elevated position at the top of said last upward flow of the gases.
Claim 10
Dependent Claim
15 words
A system as defined in claim 8 including an inverted pendulum support for said damper.
Claim 11
Dependent Claim
48 words
A system as defined in claim 9, said support comprising a horizontal beam supporting the damper, and a pair of columns at opposite ends of said beam pivotally supported at their lower ends for horizontal movement of the damper in the vertical plane of said beam and columns.
Claim 12
Dependent Claim
134 words
A recirculating dryer system comprising a furnace having a combustion chamber, a first fan supplying primary air from outside atmosphere to said combustion chamber, an outlet for said combustion chamber controlled by a damper, a second fan, an incinerating chamber between said damper and the inlet to said second fan, said second fan drawing combustion gases from said combustion chamber through said damper and incinerating chamber and discharging said gases through a discharge duct to a dryer, a return duct from the dryer conveying said combustion gases out of the dryer together with combustible substances from material being dried in the dryer, said return duct discharging into said incinerating chamber causing said combustible substances to be incinerated, and an exhaust stack venting a portion of the gas flow in said discharge duct to atmosphere.
Claim 13
Dependent Claim
134 words
A recirculating dryer system comprising a furnace having a combustion chamber, a first fan supplying primary air from outside atmosphere to said combustion chamber, an outlet for said combustion chamber controlled by a damper, a second fan, an incinerating chamber between said damper and the inlet to said second fan, said second fan drawing combustion gases from said combustion chamber through said damper and incinerating chamber and discharging said gases through a discharge duct to a dryer, a return duct from the dryer conveying said combustion gases out of the dryer together with combustible substances from material being dried in the dryer, said return duct discharging into said incinerating chamber causing said combustible substances to be incinerated, and an exhaust stack venting a portion of the gas flow in said discharge duct to atmosphere.
Claim 14
Dependent Claim
72 words
A system as defined in claim 11, said furnace being a cell type furnace with tuyeres in the cell wall and openings in the furnace grate admitting said primary air from said first fan, heat exchange means utilizing heat in said combustion gases to preheat said primary air, and heat exchange means utilizing heat in said combustion gases to heat said return flow of gases from the dryer to said incinerating chamber.
Claim 15
Dependent Claim
59 words
A system as defined in claim 12, said combustion chamber being under pressure from said first fan and said incinerating chamber being under suction from said second fan, a duct conveying a portion of said preheated primary air from said first fan to said combustion chamber, and an opening admitting air from the outside atmosphere into said incinerating chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |