# US 6,748,881 B1 · Continuous pyrolysis furnace

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 6,748,881 B1
- Document ID: US6748881B1
- Status: Granted
- Kind: B1
- Application number: 10/396,162
- Filed: 2003-03-26
- Granted: 2004-06-15
- Earliest claimed: 2003-03-26
- Assignees: Armature Coil Equipment, Inc.
- Inventors: Robert F. Heran; Robert A. Koptis
- Web page: https://patentgrep.com/patent/US6748881B1

## CPC

- F23G 5/20: having rotating or oscillating drums
- F23C 6/045: {with staged combustion in a single enclosure}
- F23G 5/0276: {using direct heating}
- F23G 5/50: Control or safety arrangements
- F23G 2203/207: with air supply ports in the sidewall
- F23G 2207/101: for temperature
- F23G 2207/102: for pressure
- F23L 2900/07008: Injection of water into the combustion chamber
- F23N 2237/22: water injection
- F23G: CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23C: METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN {A CARRIER GAS OR} AIR (burners F23D)
- F23L: SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ({air-supply arrangements for fluent fuels F23C;} firebridges with means for feeding air or steam F23M3/04; baffles or shields with air supply passages F23M9/04); VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS {(dampers and throat restrictors for open fire-places F24; air inlet valves for open fire fronts F24)}; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
- F23N: REGULATING OR CONTROLLING COMBUSTION (control devices specially adapted for combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles F23C10/28; condition responsive controls for regulating combustion in domestic stoves with open fires for solid fuel F24B1/187)

## Abstract

A pyrolysis furnace is described enabling removal of solid and liquid organic contaminants from various metal parts in a continuous manner. A novel furnace contruction employing a rotating retort vessel is described together with its method of continuous operation.

## Claims

### Claim 1

A continuous method to remove organic contaminants from metal parts in a pyrolysis furnace having an enclosure physically divided into a main combustion chamber connected to inlet and exhaust chambers, a rotating retort vessel extending thru said enclosure to enable continuous passage of contaminated metal parts thru said pyrolysis furnace, an adjustable heating rate burner to directly heat air ducted into said enclosure, and multiple supplemental combustion chambers in open communication with said furnace enclosure and vented to the atmosphere with each containing an auxiliary burner, said method comprising:
(a) operating said main combustion chamber at a positive chamber pressure while concurrently operating both inlet and exhaust chambers at a negative chamber pressure, said operation being conducted with temperature sensing means in combination with control means including programmable temperature control means to maintain continuous operation of said adjustable heating rate burner with (i) a normal fuel supply necessary to maintain full combustion of said organic contaminants in the presence of excess oxygen during a major portion of the pyrolysis cycle, said excess oxygen being relative to the amount required to burn the fuel in said burner, and (ii) a diminished supply of fuel sufficient to maintain fuel-starved combustion during the final portion of the pyrolysis, also in the presence of excess oxygen,
(b) activating a water spray within said furnace enclosure responsive to said temperature sensing means for operative cooperation with said adjustable heating rate burner to regulate operating temperatures within said furnace enclosure in accordance with a preselected heating schedule,
(c) employing multiple auxiliary burners to complete combustion of the volatized organic contaminants being transported from said furnace enclosure within said supplemental combustion chambers, and
(d) continuously supplying said contaminated metal parts to the retort vessel in said pyrolysis furnace.

### Claim 2 (depends on 1)

The method of claim 1 wherein said supplemental combustion chambers are operated at negative chamber pressure.

### Claim 3 (depends on 1)

The method of claim 1 wherein chamber pressure is monitored with manometer means.

### Claim 4 (depends on 1)

The method of claim 1 wherein volatilized organic contaminants from the retort vessel are exhausted directly to the divided chamber in said furnace enclosure.

### Claim 5 (depends on 1)

The method of claim 1 wherein the furnace control means regulates the supply of contaminant metal parts to the retort vessel so as not to exceed a preselected maximum operating temperature.

### Claim 6 (depends on 1)

The method of claim 1 wherein said furnace control means raises the operating temperature in said furnace enclosure in incremental stages.

### Claim 7 (depends on 1)

The method of claim 1 wherein operation of said adjustable heating rate burner is terminated upon completion of the pyrolysis cycle.

### Claim 8 (depends on 1)

The method of claim 1 wherein said water spray is actuated upon exceeding a preselected operating temperature in said furnace enclosure.

### Claim 9 (depends on 1)

The method of claim 1 wherein no visible smoke emerges from the supplemental combustion chambers.

### Claim 10

A continuous type pyrolysis furnace having:
(a) an enclosure physically divided into a main combustion chamber connected to inlet and exhaust chambers, said main combustion chamber operating at positive chamber pressure whereas both inlet and exhaust chambers operating at negative chamber pressure,
(b) an adjustable heating rate burner to directly heat air ducted into said enclosure,
(c) a rotating retort vessel extending thru said enclosure to enable continuous passage of metal parts contaminated with various organic materials thru said pyrolysis furnace,
(d) multiple supplemental combustion chambers in open communication with said enclosure and vented to the atmosphere with each containing an auxiliary burner,
(e) temperature sensing means disposed within said enclosure,
(f) water spray means responsive to said temperature sensing means for operative cooperation with said adjustable heating rate burner to regulate operating temperatures within said enclosure in accordance with a preselected heating schedule,
(g) control means including programmable temperature control means to maintain continuous operation of said adjustable heating rate burner with (i) a normal full supply of fuel necessary to maintain full combustion with presence of excess oxygen during a major portion of the pyrolysis cycle, said excess of oxygen being relative to the amount required to burn the fuel in said burner, and (ii) a diminished supply of fuel sufficient to maintain fuel-starved combustion during the final portion of the pyrolysis cycle, also in the presence of excess oxygen, and
(h) supply means continuously transporting said contaminated metal parts to the retort vessel in said pyrolysis furnace.

### Claim 11 (depends on 10)

The pyrolysis furnace of claim 10 wherein said adjustable heating rate burner is disposed within the main combustion chamber of said furnace enclosure.

### Claim 12 (depends on 10)

The pyrolysis furnace of claim 10 wherein temperature sensing means disposed within said main combustion chamber regulates operating temperatures within said enclosure.

### Claim 13 (depends on 12)

The pyrolysis furnace of claim 12 wherein auxiliary temperature sensing means are also disposed in the inlet and exhaust chambers of said enclosure.

### Claim 14 (depends on 13)

The pyrolysis furnace of claim 13 wherein auxiliary temperature sensing means are also disposed in the supplemental combustion chambers of said pyrolysis furnace.

### Claim 15 (depends on 10)

The pyrolysis furnace of claim 10 wherein said supplemental combustion chambers are operated at negative chamber pressure.

### Claim 16 (depends on 10)

The pyrolysis furnace of claim 10 wherein auxiliary burners disposed in said supplemental combustion chambers provide complete combustion of the volatilized organic contaminates being transported from said furnace enclosure.

### Claim 17 (depends on 16)

The pyrolysis furnace of claim 16 wherein said supplemental combustion chambers exhaust thru a common vent stack to the atmosphere.

### Claim 18 (depends on 10)

The pyrolysis furnace of claim 10 wherein chamber pressure is monitored by manometer means.

### Claim 19 (depends on 10)

The pyrolysis furnace of claim 10 wherein the furnace control means regulates the supply of contaminated metal parts to the retort vessel so as not to exceed a preselected maximum operating temperature.

### Claim 20 (depends on 10)

The pyrolysis furnace of claim 10 wherein the retort vessel includes openings enabling exhaust of the volatilized organic contaminants directly to the divided chambers in the furnace enclosure.

### Claim 21 (depends on 20)

The pyrolysis furnace of claim 20 wherein the volatilized organic contaminants are exhausted to all divided chambers.

### Claim 22 (depends on 10)

The pyrolysis furnace of claim 10 wherein the retort vessel includes inner protuberances assisting continuous passage of the contaminated metal parts during vessel rotation.

### Claim 23 (depends on 22)

The pyrolysis furnace of claim 22 wherein said inner protuberances have a helical configuration.

### Claim 24 (depends on 23)

The pyrolysis furnace of claim 23 wherein said helical protuberances includes baffle elements to mix contaminated metal parts.

### Claim 25 (depends on 22)

The pyrolysis furnace of claim 22 wherein said retort vessel also includes openings enabling exhaust of the volatilized organic contaminants directly to the divided chambers in the furnace enclosure.