RU208091U1 - Boiler for the incineration of solid municipal waste in a fluidized bed - Google Patents

Abstract

The utility model relates to the field of thermal power engineering, namely to boiler units for burning municipal solid waste in a fluidized bed. The technical result is the implementation of the possibility of burning municipal solid waste, at the required temperature, both independently and with a coal mixture. in the form of a movable grate inclined to the horizon (1) for burning solid fuel in a high-temperature fluidized bed, heating surfaces, fuel feeder, ejector, with heating surfaces in the form of gas-tight screens. Fuel is supplied by a screw type feeder (8) to an inclined plate (7) and then to the boiler furnace. Screen heating surfaces are steel, gas-tight, water-tube screens. Convective heating surfaces, made in the form of two water-tube sections (5) and (9), which ensure the reversal of gases in a vertical plane and the deposition of unburned fuel particles and fly ash in the gases in the fly ash return bin (11) with an ejector (12). A two-stage air supply is used: under the grate through the primary air blast zones (2) and into the above-layer space through the secondary blast nozzles (3). With the help of the ejector, the entrainment (12) is returned to the furnace for afterburning. The air in the primary blast zones is supplied under the grate through a bent branch pipe in the vertical direction. Secondary air is supplied to the above-layer space through slotted nozzles. Flue gases from the pressure line of the smoke exhauster are mixed into the suction line of the boiler blower fan. In the side part of the boiler lining, liquid fuel burners (4) are installed in a checkerboard pattern on both sides, directed at an angle towards the grate. 2 ill.

Description

The utility model relates to the field of heat power engineering, namely to boilers for the combustion of solid municipal waste in a fluidized bed.

Known boiler for the combustion of solid fuel in a fluidized bed according to the patent for a useful model of the Russian Federation: RU 170747 U1 dated 05.05.2017, IPC F23C 10/02 - [1], consisting of a mechanical combustion device in the form of a movable grate inclined to the horizon for burning solid fuel in a high-temperature fluidized bed with air supply under the grate and into the supra-layer space, heating surfaces in the form of gas-tight screens that provide gas turnover for organizing the entrainment return system, a fuel feeder, an ejector, an additional heating surface along the grate included in the boiler circulation loop. The fuel feeder is made in the form of a screw, the air duct in the primary blast zone under the grate is bent to a vertical position, the air duct in the secondary blast zones is made in the form of slot nozzles, the suction line of the boiler blast fan is connected to the pressure line of the flue gas fan for mixing flue gases into an additional over-grated heating surface pipe section included.

The prototype of the claimed technical solution is a boiler unit for burning solid fuel in a fluidized bed with a burner for burning liquid fuel according to the patent for a useful model of the Russian Federation: RU 172520 U1 dated 11.07.2017, IPC F23C 10/02, "Boiler unit for burning solid fuel in a fluidized bed with a burner for burning liquid fuel "- [2]. The prototype consists of a mechanical combustion device in the form of a movable grate inclined to the horizon for burning solid fuel in a high-temperature fluidized bed, heating surfaces, a fuel feeder, an ejector, with heating surfaces in the form of gas-tight screens that provide a turn of gases for organizing an entrainment return system, with air under the grate and into the above-layer space, with an additional heating surface along the grate included in the boiler circulation circuit. In the combustion device, on the upper screen, a burner for burning liquid fuel is installed, directed towards the blowing zones of the primary air of the grate.

The disadvantages of boilers [1] and [2] are:

- there is no possibility of burning municipal solid waste, both with joint supply of coal mixture, and independently;

- the inability to maintain the required temperature regime in the boiler furnace for high-quality combustion of solid municipal waste, both independently and with a joint supply of coal mixture.

The disadvantages of these boilers pose the problem of maintaining the stability of combustion and temperature conditions in static and dynamic modes when burning municipal solid waste, both independently and together with a coal mixture.

The essence of the claimed utility model is that a boiler unit for burning solid municipal waste in a fluidized bed consists of a mechanical combustion device in the form of a movable grate inclined to the horizon, then a grate, in a high-temperature fluidized bed with air supply under the grate and into the above-layer space, surfaces heating in the form of gas-tight screens, which provide a turn of gases for the organization of the entrainment return system, a fuel feeder, an ejector. The fuel feeder is made in the form of a screw. The air duct in the primary blast zone under the grate is bent to a vertical position, the air duct in the secondary blast zones is made in the form of slotted nozzles. The suction line of the blower fan of the boiler is connected to the pressure line of the flue gas exhauster for mixing flue gases. In the side part of the boiler lining, two oil burners are installed on both sides in a staggered manner, directed at an angle towards the grate.

At the same time, technical solutions of furnaces and methods of their operation are known for incineration of waste in a fluidized bed of furnaces, for example, given below:

- Waste incineration furnace according to the USSR inventor's certificate: SU 1320595 A1 dated 06/30/1987, IPC F23G 5/30 - [3], in which the waste loading device is made at the same level with the nozzles for supplying a mixture of fuel gas and air;

- A method for the disposal of combustible waste from cellulose production according to the USSR inventor's certificate: SU 1368573 A1 dated 01.23.1988, IPC F23G 5/30 - [4], according to which partial dehydration of waste is carried out, and their further combustion in a fluidized bed of an inert coolant with the initiation of horizontal counter jet flows in the surface area of the layer in the impact interaction of particles;

- A device for incineration of waste according to the USSR author's certificate: SU 1471027 A1 dated 04/07/1989, IPC F23G 5/30 - [5], containing a housing partially filled with finely dispersed material, in the upper part of which there are blow tubes, and in the lower part there are perforated pipes with visors and forming a gas distribution grid;

- Waste incinerator with a fluidized bed and a method for burning bottom sediment in such a furnace (Options) according to the patent for the invention of the Russian Federation: RU 2476772 C2 dated 02.27.2013, IPC F23G 5/30, F23G 7/04 - [6], containing the body of the incinerator , into which the bottom sludge is fed without drying, and the inner space of the incinerator body is divided into a lower part, a part above the lower part and an upper part, in the vertical direction.

A common disadvantage of the known analogs [3, 4, 5 and 6] is that they are special separate devices for waste incineration that can be used, for example, at landfills. The construction of such devices in small settlements and small towns is not advisable, since there is not a large amount of waste.

The claimed device makes it possible to expand the functionality of coal-fired boilers with a fluidized bed, namely by the fact that, along with the combustion of coal, it is possible to additionally burn crushed municipal waste in it.

The technical result of the claimed utility model is the ability to incinerate municipal solid waste, at the required temperature, both independently and with a coal mixture.

Maintaining stable combustion during the combustion of solid municipal waste in static and dynamic modes of operation, both independently and with a coal mixture in a fluidized bed, is achieved due to the fact that the prepared municipal waste, together with a coal mixture with a fraction of up to 40 mm, is directed along an inclined plate into the furnace by a screw of the fuel feeder boiler. At the same time, the operation of liquid fuel burners in the side part of the boiler lining on both sides allows maintaining the required temperature regime of the boiler unit, which allows you to completely burn solid municipal waste and generate heat for heating needs

The proposed boiler design has not been identified from the current state of the art. This allows us to conclude that it meets the “novelty” criterion.

The implementation of the claimed device does not present any technological, structural and technical difficulties, hence the compliance with the criterion "industrial applicability".

The proposed boiler design is illustrated by drawings. FIG. 1 shows a sectional view of the boiler - side view. FIG. 2 boiler section - front view. The boiler includes a mechanical combustion device, heating surfaces, a screw-type fuel feeder, an entrainment hopper and an ejector. The main technological element of the furnace is a movable grate, inclined towards the horizon, of the forward stroke (1). This device also includes a frame with an air box located inside it, divided into primary blast zones (2). The air duct in the secondary blast zones is made in the form of slotted nozzles (3). In the side part of the boiler lining, two oil burners (4) are installed on both sides in a staggered manner, directed at an angle towards the grate (1). On the sides and on top, the firebox is bounded by steel gas-tight water-tube sections (5). Fuel to the grate in the form of solid municipal waste and coal mixture is supplied from the fuel bunker (6) along the inclined plate (7) using a screw-type fuel feeder (8). The boiler also contains a water-tube section (9), a baffle (10) made of heat-resistant steel between the water tube sections (5) and (9), an entrainment return hopper (11) with an entrainment return ejector (12), a flue gas recirculation line with a rotary circular gate ...

The declared device works as follows:

The prepared composition of solid municipal waste is sent to the fuel bunker (6) where it is mixed with coal with a fraction of up to 40 mm. Further, the fuel mixture is fed to the boiler furnace along the inclined plate (7). Part of the air is directed under the grate (1) through the primary air blast zones (2), and the other - into the overlayer space through the slotted secondary blast nozzles (3).

The gases rise from the grate of the forward passage to the upper part of the furnace, pass down the row of parallel pipes of the water-tube section (5), turn 180 ° and, passing up the water-tube section (9), are removed from the boiler. To ensure the turn of the flue gases between the water-tube sections (5) and (9), a baffle made of heat-resistant steel (10) is installed. A sharp turn of gases allows unburned particles of fuel and fly ash carried away from the furnace to settle in the entrainment return hopper (11) and return them to the furnace for afterburning with the help of an ejector (12).

Shown in FIG. 2 boiler section - front view made from the side of the fuel feeder. Maintaining stable fuel combustion and the required combustion temperature not lower than 1200 ° C is due to the operation of four liquid fuel burners (4) in the boiler furnace on the side walls of the boiler lining, two on each side.

List of sources used

1. Useful model of the Russian Federation: RU 170747 U1 dated 05.05.2017, IPC F23C 10/02, "Boiler for the combustion of solid fuel in a fluidized bed."

2. Utility model of the Russian Federation: RU 172520 U1 dated 07/11/2017, IPC F23C 10/02, "Boiler unit for burning solid fuel in a fluidized bed with a burner for burning liquid fuel" - a prototype.

3. USSR author's certificate: SU 1320595 A1 dated 06/30/1987, IPC F23G5 / 30, "Waste incinerator".

4. USSR author's certificate: SU 1368573 A1 dated 01.23.1988, IPC F23G 5/30, "Method for the disposal of combustible waste from cellulose production."

5. USSR author's certificate: SU 1471027 A1 dated 04/07/1989, IPC F23G 5/30, "Waste incinerator".

6. Patent for invention of the Russian Federation: RU 2476772 C2 dated 02/27/2013, IPC F23G5 / 30, F23G 7/04, "Waste incineration furnace with a fluidized bed and a method for burning bottom sediment in such a furnace (Options)".

Claims (1)

A boiler unit for the incineration of solid municipal waste in a high-temperature fluidized bed, consisting of a mechanical combustion device in the form of a movable grate inclined to the horizon with air supply under the grate and into the above-layer space, heating surfaces in the form of gas-tight screens that provide a turn of gases for organizing the entrainment return system, a fuel feeder made in the form of a screw, an ejector, an air duct in the primary blast zone under the grate, bent to a vertical position, an air duct in the secondary blast zones, made in the form of slot nozzles, a boiler blower fan suction line connected to the smoke exhauster pressure line, for mixing outgoing gases, characterized in that in the lateral part of the lining on both sides, liquid fuel burners are installed in a staggered manner, directed at an angle towards the grate.

Images