# US 2014/0196638 A1 · Combustion device and a method for combusting granular, solid fuel

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- Number: US 2014/0196638 A1
- Document ID: US20140196638A1
- Status: Published application
- Kind: A1
- Application number: 14/343,151
- Filed: 2012-09-06
- Published: 2014-07-17
- Earliest claimed: 2011-09-06
- Assignees: Konepaja M. Pappinen Oy
- Inventors: Matti Pappinen; Mikko Pappinen
- Web page: https://patentgrep.com/patent/US20140196638A1

## CPC

- F24B 1/026: {with several combustion zones}
- F23B 30/04: with fuel-supporting surfaces that are rotatable around a horizontal or inclined axis and support the fuel on their inside, e.g. cylindrical grates
- F23L 5/02: Arrangements of fans or blowers
- F23L 9/00: Passages or apertures for delivering secondary air for completing combustion of fuel (baffles or deflectors in air inlets F23M9/02)
- F23Q 3/00: Igniters using electrically-produced sparks (sparking-plugs H01T13/00)
- F24B 1/024: {for pulverulent fuels}
- F24B 13/04: Arrangements for feeding solid fuel, e.g. hoppers
- F27B 7/30: Arrangements of partitions
- F24B: DOMESTIC STOVES OR RANGES FOR SOLID FUELS (for solid fuels in combination with gaseous fuels, liquid fuels or other kinds of energy supply F24C1/02); IMPLEMENTS FOR USE IN CONNECTION WITH STOVES OR RANGES
- F23B: METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL (for combustion of fuels that are solid at room temperatures, but burned in melted form, e.g. candle wax, C11C5/00, F23C, F23D; using solid fuel suspended in air F23C, F23D1/00; using solid fuel suspended in liquids F23C, F23D11/00; using solid fuel together with fluid fuel or with solid fuel suspended in air, simultaneously or alternately, F23C, F23D17/00)
- 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
- F23Q: IGNITION (devices or installations peculiar to internal-combustion engines F02P; of cigarettes or tobacco A24F; compositions therefor, chemical igniters C06C); EXTINGUISHING-DEVICES
- F27B: FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS

## Abstract

Disclosed is a combustion device and method for combusting granular, solid fuel, for example wood pellets. The combustion device includes a chamber having an outer wall and an inner wall, which inner wall divides the chamber into a combustion air space and a combustion chamber. Further, the combustion device includes at least one blast apparatus for providing primary combustion air and secondary combustion air and a rotating unit for rotating the combustion chamber. The inner surface of the combustion chamber includes a number of steps for lifting combustion fuel in the combustion chamber, when the combustion chamber is rotated. Further, primary combustion air is provided into the combustion chamber for contributing combustion of combustion fuel and for moving combustion fuel on the steps. In addition, secondary combustion air is provided into the combustion chamber for removing completely combusted fuel and/or combustion gases from the combustion chamber.

## Claims

### Claim at position 1

1-18. (canceled)

### Claim 19

A combustion device for combusting granular solid fuel, said combustion device comprising:
a chamber having an outer wall and an inner wall, which inner wall divides an inner space of said chamber into a combustion air space and a combustion chamber,
at least one blast apparatus for providing combustion air, and
rotating means for rotating said combustion chamber,
wherein said inner surface of said combustion chamber comprises a number of steps for lifting combustion fuel in said combustion chamber, and
at least one aperture is provided through at least one step for directing a primary combustion air into said combustion chamber in a direction substantially parallel to and/or along a circumference of said combustion chamber for contributing combustion of combustion fuel and for moving said combustion fuel on said steps,
and said combustion chamber comprises at least one aperture for providing a secondary combustion air into said combustion chamber in a direction substantially parallel to a rotation axis of said combustion chamber for removing completely combusted fuel and optionally combustion gases from said combustion chamber,
wherein the rotating movement of the combustion chamber provided by said rotating means and said primary combustion air together elevate completely combusted fuel into said secondary combustion air in order to be removed from said combustion chamber.

### Claim 20 (depends on 19)

A combustion device according to claim 19, wherein said combustion chamber is a shape of a cylinder having an open end for removing completely combusted fuel from said combustion chamber.

### Claim 21 (depends on 19)

A combustion device according to claim 19, wherein said combustion device further comprises an afterburning part, comprising an output opening for removing completely combusted fuel from said combustion chamber, which afterburning part is in connection with said combustion chamber for preventing incompletely combusted material to exit from said combustion chamber.

### Claim 22 (depends on 21)

A combustion device according to claim 21, wherein the radius of said output opening of said afterburning part is 10%-40% smaller than the radius of the open end of the combustion chamber.

### Claim 23 (depends on 21)

A combustion device according to claim 21, wherein the radius of said output opening of said afterburning part is 15%-35% smaller than the radius of the open end of the combustion chamber.

### Claim 24 (depends on 21)

A combustion device according to claim 21, wherein the radius of said output opening of said afterburning part is 20%-30% smaller than the radius of the open end of the combustion chamber.

### Claim 25 (depends on 21)

A combustion device according to claim 21, wherein afterburning combustion air is provided into the afterburning part and at least one aperture is provided through said afterburning part for directing afterburning combustion air into the end of said combustion chamber for ensuring complete combustion of said combustion fuel and combustion gases.

### Claim 26 (depends on 19)

A combustion device according to claim 19, wherein said combustion air space is continuous.

### Claim 27 (depends on 19)

A combustion device according to claim 19, wherein one blast apparatus provides both primary combustion air and secondary combustion air.

### Claim 28 (depends on 19)

A combustion device according to claim 19, wherein said steps are coupled together.

### Claim 29 (depends on 19)

A combustion device according to claim 19, wherein said steps are L-profile-shaped.

### Claim 30 (depends on 29)

A combustion device according to claim 29, wherein said aperture/apertures is/are provided to the short side of said L-shaped step.

### Claim 31 (depends on 19)

A combustion device according to claim 19, wherein the rotating movement of said combustion chamber is pulsating.

### Claim 32 (depends on 31)

A combustion device according to claim 31, wherein said pulsating rotating movement of said combustion chamber is adjustable according to the fuel type and/or size.

### Claim 33 (depends on 19)

A combustion device according to claim 19, wherein said device further comprises a feeding device comprising a feeding tube, a protective valve, conveying means, a flame control system and/or extinguishing equipment for feeding combustion fuel to said combustion chamber and for controlling the feeding and/or ignition process.

### Claim 34 (depends on 19)

A combustion device according to claim 19, wherein said device further comprises a lighting means, such as electric and/or wire-wound resistor, for igniting said combustion fuel by means of heating said combustion air.

### Claim 35 (depends on 19)

A method for combusting granular, solid fuel using combustion device according to claim 19, comprising at least following phases:
feeding granular, solid, ignited fuel to the beginning of said combustion chamber;
providing said combustion chamber into a rotating movement for lifting fuel by means of said steps forming the inner surface of said combustion chamber;
providing primary combustion air into said combustion chamber in a direction substantially parallel to and/or along the circumference of said combustion chamber for combusting and moving said combustion fuel in said combustion chamber;
providing secondary combustion air into said combustion chamber in a direction substantially parallel to a rotation axis of said combustion chamber for removing completely combusted fuel and/or combustion gases from said combustion chamber.

### Claim 36 (depends on 35)

A method according to claim 35 further comprises following phases:
providing combustion air through aperture(s) provided through said afterburning part in a substantially radial direction of the afterburning part into the end of said combustion chamber for ensuring complete combustion of combustion fuel and/or combustion gases.

### Claim 37 (depends on 20)

A method for combusting granular, solid fuel using combustion device according to claim 20, comprising at least following phases:
feeding granular, solid, ignited fuel to the beginning of said combustion chamber;
providing said combustion chamber into a rotating movement for lifting fuel by means of said steps forming the inner surface of said combustion chamber;
providing primary combustion air into said combustion chamber in a direction substantially parallel to and/or along the circumference of said combustion chamber for combusting and moving said combustion fuel in said combustion chamber;
providing secondary combustion air into said combustion chamber in a direction substantially parallel to a rotation axis of said combustion chamber for removing completely combusted fuel and/or combustion gases from said combustion chamber.

### Claim 38 (depends on 21)

A method for combusting granular, solid fuel using combustion device according to claim 21, comprising at least following phases:
feeding granular, solid, ignited fuel to the beginning of said combustion chamber;
providing said combustion chamber into a rotating movement for lifting fuel by means of said steps forming the inner surface of said combustion chamber;
providing primary combustion air into said combustion chamber in a direction substantially parallel to and/or along the circumference of said combustion chamber for combusting and moving said combustion fuel in said combustion chamber;
providing secondary combustion air into said combustion chamber in a direction substantially parallel to a rotation axis of said combustion chamber for removing completely combusted fuel and/or combustion gases from said combustion chamber.