Patent US3072542A successfully refreshed from Google Patents.
Patent US3813209A successfully refreshed from Google Patents.
US3813209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preheating of metal scrap
Assignee: Inductotherm Corp
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Filing: 1973-02-26
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Granted: 1974-05-28
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Expires: 1993-02-26
Abstract
Abstract Metal scrap is deposited in a predetermined amount and in a generally uniform bed on the receiving end of a conveyor. The bed of scrap is moved into a tunnel furnace for preheating. A plurality of burners are supported on the top wall of the furnace, each burner mixing fuel, such as gas or oil, with air, and the mixture is ignited. The burner products, at high heat, jet from the respective burner at high velocity and down onto the scrap and penetrate the latter so as to quickly heat the scrap to required temperature. Smoke and fumes issuing from heated scrap are entrained by the jetting burner products and are largely consumed thereby. The improved apparatus, and the method of operating the same, result in economies in capital investment, operating costs and plant space required, since the scrap is so quickly preheated that successive batches may be preheated and deposited into a charging bucket and subsequently delivered to a melt furnace, without any appreciable heat loss.
Inventors
- 👤 H Venetta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:46
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/56; C21C5/562; C21C5/565; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S266/00; Y10S266/901
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
125 words
Apparatus for preheating metal scrap, comprising: a conveyor having a horizontal surface upon which scrap is positioned in substantially level manner, said conveyor having a delivery end whereat scrap is loaded thereon, and a discharge end, a tunnel furnace through which said scrap is moved by said conveyor, burner means within said furnace, said burner means being of the high velocity type and having the flame outlet thereof arranged relative to the scrap on the conveyor so that the burner products jet from the outlet at high velocity in a direction normal to the scrap therebelow and close enough to penetrate the same, whereby to quickly and evenly heat said scrap, and means at the discharge end of said conveyor for receiving the heated scrap.
Claim 2
Dependent Claim
125 words
Apparatus for preheating metal scrap, comprising: a conveyor having a horizontal surface upon which scrap is positioned in substantially level manner, said conveyor having a delivery end whereat scrap is loaded thereon, and a discharge end, a tunnel furnace through which said scrap is moved by said conveyor, burner means within said furnace, said burner means being of the high velocity type and having the flame outlet thereof arranged relative to the scrap on the conveyor so that the burner products jet from the outlet at high velocity in a direction normal to the scrap therebelow and close enough to penetrate the same, whereby to quickly and evenly heat said scrap, and means at the discharge end of said conveyor for receiving the heated scrap.
Claim 3
Dependent Claim
50 words
The construction according to claim 1 wherein said furnace has an exhaust stack, and wherein said burner means is so disposed that the downwardly jetting burner products are at a slight angle inclined toward said exhaust stack to provide momentum to any exhaust gases in a direction toward said stack.
Claim 4
Dependent Claim
44 words
The construction according to claim 1 wherein said conveyor is of the shaker feed type, including an elongaged horizontally disposed trough, and means for feeding scrap to the delivery end of said conveyor and depositing it on said trough in a substantially level bed.
Claim 5
Dependent Claim
79 words
The construction according to claim 3, wherein means are provided to halt shaking operation of said conveyor for a predetermined time when said scrap is disposed within said tunnel furnace, and means for operating said burner means at high heat and velocity during the time operation of said conveyor is halted and said bed of scrap is within said furnace so that the downwardly jetting buRner products strike said bed of scrap at high velocity and penetrate the same.
Claim 6
Dependent Claim
86 words
The construction according to claim 4, wherein at high heat said air and fuel are at a high volume with an excess fuel ratio, and further including means operable to change said burner means to low heat by reducing the total volume of fuel and air delivered to said burner means while maintaining the same excess fuel ratio, said means to reduce being operable after said predetermined time and while operation of said conveyor is still halted, to substantially maintain the temperature of the preheated scrap.
Claim 7
Dependent Claim
37 words
The construction according to claim 5, wherein operation of said conveyor is effected to deliver said heated scrap to scrap receiving means after said burner means has been on low heat for a predetermined amount of time.
Claim 8
Dependent Claim
60 words
The construction according to claim 6, wherein the means to receive preheated scrap is one of a pair of melt-furnace charging buckets, said buckets being mounted on a car which is movable transversely of said conveyor at the discharge end thereof, whereby one bucket may be charged with scrap while the other is moved to and from the melt furnace.
Claim 9
Dependent Claim
29 words
The construction according to claim 6, wherein the means to receive preheated scrap is a transversing shaker-feed charging car that is movable to one of a plurality of furnaces.
Claim 10
Dependent Claim
51 words
The construction according to claim 1, wherein said burner means combines fuel and air and ignites the same to provide said burner products, and wherein means are provided to preheat the air flowing to said burner means, the air preheating means in heat transfer relationship with hot gases of the furnace.
Claim 11
Independent Claim
112 words
The method of preheating metal scrap for charging into a melt furnace wherein said furnace requires preheated metal scrap charged into it at predetermined time intervals, comprising: depositing scrap in a generally even bed on the surface of a conveyor, operating said conveyor to move said bed of scrap into a tunnel furnace which has burner means in its upper portion operable at high heat to direct burner products downwardly onto said scrap at high velocity, maintaining said bed of scrap within said tunnel furnace for a period of time less than said predetermined time interval, and thereafter discharging the preheated scrap into a receiving member for transportation to said melt furnace.
Claim 12
Independent Claim
112 words
The method of preheating metal scrap for charging into a melt furnace wherein said furnace requires preheated metal scrap charged into it at predetermined time intervals, comprising: depositing scrap in a generally even bed on the surface of a conveyor, operating said conveyor to move said bed of scrap into a tunnel furnace which has burner means in its upper portion operable at high heat to direct burner products downwardly onto said scrap at high velocity, maintaining said bed of scrap within said tunnel furnace for a period of time less than said predetermined time interval, and thereafter discharging the preheated scrap into a receiving member for transportation to said melt furnace.
Claim 13
Dependent Claim
107 words
The method of claim 10, wherein the ratio of fuel to air at high heat of said burner means is such that the fuel is in excess, wherein said burner means is operated at high heat for a portion of said predetermined time interval while said bed of scrap is maintained within said tunnel furnace, and wherein said burner means is operated at a reduced heat for another portion of said predetermined time interval while said bed of scrap is maintained within said tunnel furnace, at reduced heat the total volume of fuel and oil being reduced while the excess ratio of fuel to air is maintained.
Claim 14
Dependent Claim
97 words
The method of claim 10, wherein said melt furnace requires a predetermined amount of preheated scrap at predetermined time intervals, including, depositing a portion of said predetermined amount of scrap on said conveyor and moving it to said tunnel furnace for preheating said subsequent discharge into a melt-furnace charging bucket, and thereafter depositing the remaining portion of said predetermined amount of scrap on said conveyor and moving it to said tunnel furnace for preheating and subsequent discharge into the same charging bucket, whereby the length of said conveyor and tunnel furnace may be held to a minimum.
Claim 15
Independent Claim
95 words
The method of preheating metal scrap in a tunnel furnace wherein burner means is located in the top wall of said furnace and directs its burner products downwardly onto said scrap at high velocity, said burner means mixing fuel and air with an excess fuel ratio and igniting the mixture to form the burner products, the improvement for reducing explosions which may be caused by flameOuts, comprising, maintaining the temperature within the furnace adjacent to said top wall at a degree high enough to insure automatic ignition of the mixture issuing from said burner means.
Claim 16
Independent Claim
95 words
The method of preheating metal scrap in a tunnel furnace wherein burner means is located in the top wall of said furnace and directs its burner products downwardly onto said scrap at high velocity, said burner means mixing fuel and air with an excess fuel ratio and igniting the mixture to form the burner products, the improvement for reducing explosions which may be caused by flameOuts, comprising, maintaining the temperature within the furnace adjacent to said top wall at a degree high enough to insure automatic ignition of the mixture issuing from said burner means.
Claim 17
Dependent Claim
56 words
The method according to claim 13, and further including operating said burner means at various heats, which includes changing total volumes of fuel and air while maintaining said fuel and air mixture at an excess fuel ratio to maintain a hot flame within said furnace adjacent to said top wall to thereby maintain automatic ignition temperature.
References Cited (Backward Citations)
US2623740A
Cited
US2948630A
Cited
US3556500A
Cited
US3656735A
Cited
US3667747A
Cited
US3758267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |