CN110285425A - Incinerators that use furnace flue gas to dry fuel in the drying section - Google Patents

Abstract

The invention relates to an incinerator in which furnace flue gas is used to dry fuel in the drying section. An induced draft fan and a dust collector are arranged under the grate of the drying section, and a primary air preheater and a primary air blower are arranged under the grate of the burning section and the grate of the burnout section. , the high-temperature gas drawn out is passed into the furnace and a flue injection port, and the solid waste enters the incinerator from the inlet of the incinerator, and then passes through the drying section grate, the combustion section grate, and the burnout section to form slag and passes through the incinerator The slag outlet is discharged. The induced draft fan introduces the high-temperature flue gas from the combustion section in the furnace into the drying section, and the high-temperature flue gas flows through the solid waste accumulation layer above the grate in the drying section, so that the water in it evaporates to play a drying role, and at the same time, partial pyrolysis and gasification of the solid waste occur , the generated gas passes through the dust collector and induced draft fan, then passes through the furnace and a flue injection port, and realizes full combustion in the furnace or a flue. The incinerator of the invention can realize high-efficiency combustion and improve boiler efficiency.

Description

Incinerators that use furnace flue gas to dry fuel in the drying section

technical field

The invention relates to garbage incineration technology, in particular to an incinerator in which a drying section adopts furnace flue gas to dry fuel.

Background technique

For solid waste, especially garbage, the moisture content of the garbage entering the furnace is generally distributed between 40% and 55%, which affects the ignition and combustion of the garbage entering the furnace. Therefore, the general facilities of waste grate furnaces used in China include drying section, combustion section, and burnout section. The primary air is used as a combustion aid to realize the drying, burning and burning of solid waste.

In the drying section of the incinerator, primary air (150°C-250°C) is generally used for drying. However, the drying rate of the primary air is slow, and the drying section is set longer; at the same time, the drying wind in the drying section causes a high air excess coefficient, which affects the boiler efficiency.

In view of this, those skilled in the art are studying how to improve the drying measures at the drying section of the incinerator.

Contents of the invention

The task of the present invention is to provide an incinerator in which the drying section uses furnace flue gas to dry fuel. In the drying section of the incinerator, primary air is not supplied to the furnace, but an induced draft fan is installed to introduce high-temperature flue gas from the combustion section in the furnace into the drying section. , and then realize the drying of the drying section, and at the same time realize partial pyrolysis and gasification of the drying section, and realize high-efficiency combustion, which solves the problem of the slow drying rate of the primary air used in the prior art, the long setting of the drying section, and the excessive air caused by the drying wind in the drying section The higher coefficient affects the efficiency of the boiler.

Technical solution of the present invention is as follows:

An incinerator whose drying section uses furnace flue gas to dry fuel, which includes an incinerator inlet, an incinerator outlet, a drying section grate, a burning section grate, a burnout section grate, an incinerator slag outlet, a furnace and a smoke channel injection port;

An induced draft fan and a dust collector are arranged under the grate of the drying section, and a primary air preheater and a primary air blower are arranged under the grate of the burning section and the grate of the burnout section, and the high-temperature gas drawn out is passed into the furnace and a primary air blower. The flue injection port, the solid waste enters the incinerator from the incinerator entrance, passes through the drying section grate, the combustion section grate, and the burnout section in turn, and then forms slag and is discharged through the slag outlet of the incinerator;

The induced draft fan introduces the high-temperature flue gas from the combustion section in the furnace into the drying section, and the high-temperature flue gas flows through the solid waste accumulation layer above the grate in the drying section, so that the water in it evaporates to play a drying role, and at the same time, part of the solid waste undergoes pyrolysis and dehydration. Gasification, the generated gas passes through the dust collector and induced draft fan, then passes through the furnace and a flue injection port, and realizes full combustion in the furnace or a flue.

The solid waste accumulation height above the grate in the drying section should exceed 0.5m.

The dust collector is arranged before the position of the induced draft fan.

The temperature of the grate in the drying section should be reduced to within 600°C after the high-temperature flue gas passes through, so as to ensure the safety of the grate.

Adjust the air volume in the combustion section during work, and the oxygen content of the generated flue gas should be controlled below 7%.

A kind of incinerator of the present invention adopts furnace flue gas to dry fuel in the drying section. A multi-stage combustion grate furnace is provided. 0-30% of the high-temperature flue gas formed by the garbage above the grate of the combustion section flows through the drying section under the action of the induced fan under the grate of the drying furnace The solid waste layer enters the furnace and a flue through the grate and induced draft fan in the drying section to achieve high-efficiency combustion.

The biggest highlight of the incinerator of the present invention is that the primary air is not supplied to the furnace in the drying section, but an induced draft fan is installed to introduce the high-temperature flue gas from the combustion section in the furnace into the drying section, thereby realizing the drying of the drying section and simultaneously realizing the drying of the drying section. Partial pyrolysis and gasification.

The oxygen content of the high-temperature flue gas in the combustion section is low, generally less than 6%. Therefore, after the wet garbage is exposed to high-temperature flue gas in the drying section, it is mainly dried and pyrolyzed, and combustion rarely occurs.

The thickness of the garbage layer in the drying section is higher than 0.5m. After the high-temperature flue gas passes through the garbage in the drying section, it passes through the grate, and the temperature has dropped to below 600°C, which will not affect the safety of the grate.

The gas produced after drying is passed into the furnace and a flue to achieve full combustion. At the same time, the dried gas contains reducing gas (CO, NH ₃ ), which is mixed with high-temperature flue gas in the furnace to reduce the amount of NO _x generated through reduction.

Due to the low oxygen content in the high-temperature flue gas, it is possible to achieve partial pyrolysis and gasification of the drying section while drying in the drying section, and the generated gas can be passed into the furnace or a flue to achieve efficient combustion; and the gas in the Contains reducing gas, which is passed into the incinerator again to achieve low _NOx combustion.

The drying section of the incinerator of the present invention does not need primary air drying, which can effectively reduce the overall excess air coefficient of the incinerator and improve boiler efficiency.

Description of drawings

Fig. 1 is a schematic structural view of an incinerator which uses furnace flue gas to dry fuel in the drying section of the present invention.

Reference signs:

1 is the outlet of the incinerator, 2 is the entrance of the incinerator, 3 is the grate of the drying section, 4 is the grate of the combustion section, 5 is the grate of the burnout section, 6 is the slag outlet of the incinerator, 7 is the induced draft fan, and 8 is the dust removal 9 is a primary air preheater, 10 is a primary air blower, and 11 is a furnace and a flue injection port.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to Fig. 1, the present invention provides a kind of incinerator that drying section adopts furnace flue gas to dry fuel, and it mainly consists of drying section fire grate 3, combustion section fire grate 4, burnout section fire grate 5, incinerator slag outlet 6, Composed of a furnace and a flue injection port 11, the incinerator is provided with an incinerator inlet 2 and an incinerator outlet 1.

An induced draft fan 7 and a dust collector 8 are arranged below the grate 3 of the drying section, and a primary air preheater 9 and a primary air blower 10 are arranged below the grate 4 of the combustion section and the grate 5 of the burnout section. The extracted high-temperature gas is passed into the furnace and a flue injection port 11, and the solid waste enters the incinerator from the incinerator inlet 2, and then passes through the drying section grate 3, the combustion section grate 4, and the burnout section grate 5 to form The slag is discharged through the slag outlet 6 of the incinerator.

The induced draft fan 7 introduces the high-temperature flue gas from the combustion section in the furnace into the drying section, and the high-temperature flue gas flows through the solid waste accumulation layer above the grate 3 in the drying section, so that the water in it evaporates to play a drying role, and at the same time, part of the solid waste undergoes pyrolysis and dehydration. After gasification, the generated gas passes through the dust collector 8 and the induced draft fan 7, then passes through the furnace and a flue injection port 11, and realizes full combustion in the furnace or a flue.

The solid waste accumulation height above the grate 3 in the drying section should exceed 0.5m, and the temperature of the high-temperature flue gas passing through the grate 3 in the drying section should be reduced to within 600°C to ensure the safety of the grate.

The grate 3 in the drying section and the induced draft fan 7 on the pipeline are required to work safely within 600°C.

Since the high-temperature flue gas contains some particles after passing through the solid waste in the drying section and the grate, it is necessary to install an ash removal system such as a dust collector 8 under the grate and in front of the induced draft fan.

Adjust the air volume in the combustion section during work, and the oxygen content of the generated flue gas should be controlled below 7%.

The operation process of the incinerator using furnace flue gas to dry fuel in the drying section of the present invention is as follows: solid waste enters the incinerator from the incinerator inlet 2, and passes through the drying section grate 3, the combustion section grate 4, and the burnout section grate successively. After 5, the slag formed is discharged through the slag outlet 6 of the incinerator.

Above the grate 4 in the combustion section, solid waste is burned to produce high-temperature flue gas, the temperature of which is higher than 1000°C, and part of the high-temperature flue gas (0%-30%) flows through the grate 3 in the drying section under the action of the induced draft fan 7 The upper solid waste accumulation layer and the drying section fire grate 3, the high-temperature flue gas flows through the solid waste layer, so that the water in it evaporates and plays a drying role. At the same time, part of the solid waste undergoes pyrolysis and gasification, and the generated gas passes through the dust collector 8. Behind the induced draft fan 7, it passes through the furnace and a flue injection port 11 to realize full combustion in the furnace or a flue.

In summary, in the drying section of the present invention, the incinerator that uses furnace flue gas to dry fuel does not supply primary air to the furnace in the drying section of the incinerator, but sets an induced draft fan to introduce high-temperature flue gas from the combustion section in the furnace into the drying section. Then realize drying in the drying section, and at the same time realize partial pyrolysis and gasification in the drying section, realize efficient combustion, and improve boiler efficiency.

Of course, those skilled in the art should recognize that the above-mentioned embodiments are only used to illustrate the present invention, rather than to limit the present invention. , modification, etc. will all fall within the scope of the claims of the present invention.

Claims (5)

1. a kind of dryer section uses the incinerator of burner hearth flue gas drying fuel, it includes incinerator entrance (2), burns outlet of still (1), dryer section fire grate (3), burning zone fire grate (4), after-flame section fire grate (5), incinerator slag notch (6), burner hearth and flue spray Loophole (11), it is characterised in that:

Air-introduced machine (7) and deduster (8), the burning zone fire grate (4), after-flame section are provided with below the dryer section fire grate (3) Primary air preheater (9) is provided with below fire grate (5) and primary air air blower (10), the high-temperature gas of extraction are passed into furnace Thorax and an in duct sorbent injection mouth (11), solid waste enter incinerator from incinerator entrance (2), successively by dryer section fire grate (3), combustion Burn section fire grate (4), after-flame section fire grate (5) forms clinker afterwards and is discharged by incinerator slag notch (6)；

Furnace chamber inner combustion section high-temperature flue gas is introduced dryer section by the air-introduced machine (7), and high-temperature flue gas flows through on dryer section fire grate (3) The solid waste stack layer of side so that wherein desiccation is played in moisture evaporation, while occurring partial thermal decomposition and gasification, generates in solid waste Gas by deduster (8), after air-introduced machine (7), through burner hearth and an in duct sorbent injection mouth (11), in burner hearth or a flue Realize full combustion.

2. the incinerator that dryer section according to claim 1 uses burner hearth flue gas drying fuel, it is characterised in that: described dry Solid waste piling height should be more than 0.5m above dry section of fire grate (3).

3. the incinerator that dryer section according to claim 1 uses burner hearth flue gas drying fuel, it is characterised in that: described to remove Dirt device (8) is arranged before air-introduced machine (7) position.

4. the incinerator that dryer section according to claim 1 uses burner hearth flue gas drying fuel, it is characterised in that: described dry Dry section of fire grate (3) temperature after high-temperature flue gas passes through should be reduced within 600 DEG C, to guarantee fire grate safety.

5. the incinerator that dryer section according to claim 1 uses burner hearth flue gas drying fuel, it is characterised in that: when work Burning zone air capacity is adjusted, the flue gas oxygen content of generation should control below 7%.