KR20060126129A - An incinerator with fixed type water-cooled combustion grate - Google Patents

Abstract

An incinerator with a fixed type water-cooled combustion grate is provided to reduce emission of environmental contaminants by maintaining the temperature of a combustion chamber in the incinerator at a high level so that waste is completely burnt. An incinerator uses a fixed type water-cooled combustion grate(101), uses air(111) at a surface of a combustion chamber as combustion air(103,104), and uses a mixture(107) of high temperature combustion gas(105) of the combustion chamber and outdoor air(106), as combustion air(108).

Description

Fixed Water Cooled Grate Incinerator {AN INCINERATOR WITH FIXED TYPE WATER-COOLED COMBUSTION GRATE}

1 is a conventional mobile air-cooled grate incinerator system,

2 is a fixed water-cooled grate incinerator system of the embodiment according to the present invention,

Figure 3 is a fixed water-cooled grate to enter the fixed water-cooled grate incinerator of the embodiment according to the present invention.

* Explanation of symbols for the main parts of the drawings

1: removable air cooled grate

2: primary combustion air blower for main combustion chamber

3: secondary combustion chamber air supply blower 4: secondary combustion chamber air supply

5: waste supply port 6: auxiliary combustion chamber burner blower

7: 2nd combustion chamber bypass duct 8: 1st combustion chamber control system

9: auxiliary combustion chamber combustion burner duct 10: auxiliary combustion burner device

11: Simultaneous control system of primary combustion chamber and secondary combustion chamber

12: Primary combustion air supply duct for main combustion

101: fixed water-cooled grate 102: surface air suction in the primary combustion chamber

103: primary combustion chamber surface air suction blower (secondary combustion chamber air supply blower)

104: secondary combustion chamber air supply

105: secondary combustion chamber combustion gas suction duct 106: primary combustion chamber combustion air

107: blower for supplying combustion gas

108: first and second burned combustion gas supply ducts

109: primary combustion chamber burner duct 110: primary combustion chamber burner

111: primary combustion chamber surface

112: air supply duct for the primary combustion chamber main combustion

113: simultaneous control of the primary and secondary combustion chambers

114: primary combustion chamber control system 115: secondary combustion chamber bypass duct

116: primary combustion chamber burner blower 117: waste inlet

118: primary combustion air blower

201: Primary fixed water-cooled grate 202: Secondary fixed water-cooled grate

203: third fixed water-cooled grate

204: primary combustion chamber water injection spray nozzle 205: waste feeder

206: boiler feed pump 207: deaerator

208: boiler water supply line

209: first fixed water-cooled grate cooling line

210: second fixed water-cooled grate cooling line

211: 3rd stationary water-cooled grate cooling line 212: coal cutter

The present invention relates to a grate cooling system for cooling a fixed grate using boiler water as cooling water, wherein high temperature air on the surface of a primary combustion chamber is used as combustion air in a secondary combustion chamber, and unreacted combustion gas and combustion in the secondary combustion chamber are used. It relates to a waste stationary water-cooled grate incinerator that mixes air and resupply it to the combustion air in the primary combustion chamber.

Waste incinerators can be divided into grate incinerators, fluidized bed incinerators and rotary furnace incinerators according to the method of incineration of wastes. Among them, a grate incinerator using a fixed water-cooled grate in a grate incinerator in which waste is placed on a grate and incinerated is the object of the present invention.

Conventional grate combustion incinerator is a technology to incinerate waste by injecting waste to be incinerated by installing fixed grate or mobile grate in the furnace. Grate type is widely used in staircase, multi-stage cylindrical rotary type, but all conventional grate incinerators The grate cooling method of the air intake type is air-cooled to inject the combustion air from the lower part of the grate to achieve grate cooling.

When the air-cooled grate is used, the thermal conductivity of the air lowers its own thermal conductivity, thereby limiting the grate's cooling.As a result, the grate's high temperature corrosion is accelerated to shorten the grate's life and reduce the overall life of the incinerator. Significant increases in costs for damage and maintenance of wastes and local incomplete combustion can also interfere with the control of pollutants generated during incineration.

In particular, since it is not easy to cool the grate below 400 ° C as air, an expensive nickel-chromium steel, etc., which is resistant to high temperatures and corrosion, is used as the material of the grate. The result is an increase in the economic burden of increasing treatment costs.

The conventional air-cooled grate incinerator as described above has technical limitations and economic cost increase burden of incineration of waste due to the mechanical and thermal characteristics of the grate, and also the air-cooled grate incinerator is the lowest decomposition temperature of hardly decomposable materials. Incineration operation can only be performed at a temperature of about 850 ° C. or higher, which causes problems such as preventing the generation of environmental pollutants.

In addition, the injection of combustion air in the conventional grate incinerator consists of a primary combustion air injected into the lower portion of the waste and a secondary combustion air injection system injected into the upper portion of the waste. There are limitations such as that the secondary combustion air only has to flow air at room temperature (20 ° C to 40 ° C) outside the incinerator into the combustion chamber.

The present invention uses a fixed water-cooled grate made of inexpensive carbon steel instead of a low-temperature combustion air-cooled grate made of a conventional high-priced special material, while maintaining a high temperature combustion chamber temperature that could not be achieved in an air-cooled grate incinerator. By using air as the combustion air in the secondary combustion chamber and re-supply to the primary combustion chamber to minimize the heat loss in the combustion chamber.

In other words, the incineration mechanism that injects the combustion air at room temperature outside the incinerator into the combustion chamber and incinerates the waste is reused as the combustion air by mixing the hot air around the grate surface with the combustion gas through the bypass duct. In addition to the heat of the waste itself, the combustion efficiency of the waste is maximized by the sensible heat of the combustion air.

Therefore, the technical problem to be achieved by the present invention is to achieve a complete incineration of waste by incineration of the temperature of the combustion chamber in the incinerator to incinerate waste by using a water-cooled grate made of low-cost carbon steel material to achieve environmental incineration such as dioxin, nitride, environmental pollution The use of a fixed grate, rather than the grate itself, reduces the occurrence of friction, wear, erosion and corrosion caused by the movement of the grate and the fixed grate. By maintaining at a higher temperature to achieve the heat accumulation effect and the like.

Hereinafter, with reference to Figures 2 to 3 will be described in detail with respect to the technical configuration and effect of the present invention.

1 shows an incinerator system with a conventional mobile air grate in general. In the conventional mobile air-cooled grate system of FIG. 1, waste enters a primary combustion chamber equipped with a multi-stage mobile air-cooled grate 1 through a waste supply port 5 by a feeder such as a conveyor or a roller.

The supplied waste is combusted by the ambient air combustion air supplied through the primary combustion air main duct 12 by the primary combustion air blower 2 above the mobile air-cooled grate 1, Waste is moved by the movement of the moving air-cooled grate and fed to the upper surface of the fixed grate.

Since unburned combustion gas generated by the combustion air and the combustion reaction has a large amount of environmental pollutants, the waste is supplied to the secondary combustion chamber to completely burn the combustion gas generated during the primary combustion process. The primary combustion gas supplied from is reburned by re-reacting with the air at room temperature of the incinerator outside air supplied to the secondary combustion air blower (3), and then through the combustion gas outlet through the secondary combustion chamber bypass duct (7). Move.

The control of the temperature and pressure inside the combustion chamber is controlled by the primary combustion chamber control system 8 and the joint control system 11 of the primary and secondary combustion chambers, and the internal combustion chamber generated by the combustion of wastes supplied to the combustion chamber. When the calorie is insufficient, the auxiliary combustion burner device 10 for supplying a separate calorie in the primary combustion chamber is installed to compensate for this. In the auxiliary combustion burner device, the fuel supplied through the auxiliary fuel supply line and the outside air supplied through the auxiliary combustion chamber combustion burner duct 9 by the auxiliary combustion chamber burner blower 6 are supplied to the auxiliary combustion burner device 10 for combustion. As a result, the temperature inside the combustion chamber is increased.

When a low calorific amount of waste is frequently introduced into a mobile air-cooled grate incinerator as in the prior art, and the combustion air 12 and 4 at ambient temperature is used, the auxiliary combustion burner device does not maintain an appropriate temperature. There is a problem that excessive use of 10). On the other hand, incineration of waste is incinerated under a control system (8, 11) that controls the temperature of the combustion gas in the combustion chamber regardless of the amount of heat generated by the waste at temperatures above 850 ° C in order to achieve complete combustion of the combustion gas. It is prescribed by law.

In order to reduce the generation of environmental pollutants such as hardly decomposable unsaturated compounds and dioxins in waste incinerators, the combustion conditions must be maintained in incinerators at temperatures higher than 850 ° C. Mobile air-cooled grate incinerators have various constraints such as abrasion and corrosion due to mutual movement by fixed grate structures, cooling ability to cool grate, etc. The grate of has a disadvantage of not being able to satisfy the thermal load rate and mechanical load rate in the combustion chamber due to the rapid occurrence of corrosion, abrasion, and erosion at high temperature, resulting in weak mechanical strength of the grate.

Therefore, the present invention proposes a fixed water-cooled grate incinerator system to solve the above problems. Figure 2 shows a schematic system of the present inventors fixed water cooling grate incinerator.

In the present invention, instead of the air-cooled grate (1) of Figure 1 is provided with a water cooling conduit formed in a zigzag by a diaphragm fixed to the upper and lower surfaces of the water-cooled grate alternately fixed to both sides of the grate, One side is formed with a supply port of the water-cooled grate through which the coolant is introduced and a discharge port circulated along the water cooling line to discharge the coolant, and a combustion air supply port through which the combustion air is supplied through the upper and lower surfaces of the water-cooled grate. A fixed water-cooled grate 101 is provided.

Waste is supplied to the primary combustion chamber equipped with the fixed water cooling grate 101 through the waste supply port 117 by waste supply systems such as conveyors, rollers, and hoppers. The supplied waste is burned to the outside air at room temperature supplied from the lower portion of the water cooling grate through the primary combustion chamber main combustion air supply duct 112 by the primary combustion chamber main combustion air blower 118 above the fixed water cooling grate 101. The combustion gas combusted in the secondary air and the secondary combustion chamber is moved to the outlet through the secondary combustion chamber bypass duct, and a part of the first and second combustion gases of high temperature combustion gas is supplied through the combustion gas supply blower 107. It is combusted by the high-temperature primary and secondary combustion combustion gas supplied to the primary combustion chamber above the fixed water cooling grating through the duct 108.

The fixed water-cooled grate 101 is a water-cooled structure in which the boiler circulating water flows as a coolant in the inside of the grate in which waste is moved, thereby minimizing wear-erosion corrosion between grates, thereby extending the life of the grate. Maintain a constant low temperature grate surface temperature.

Even when the temperature of the grate surface is in the range of 150 ~ 200 ℃ which is the temperature of the boiler water, the grate surface is kept at a low temperature compared with the case where the temperature of the grate surface cannot be lowered below 400 ℃ of the air-cooled type. Without the need for expensive superalloys such as mobile air-cooled grates, the grate can be made of ordinary low-cost carbon steel to maintain the metallic properties of high-temperature combustion.

In addition, when the fixed water-cooled grate is used, since the temperature in the combustion chamber at a high temperature of 1000 ° C. or more is maintained, incomplete combustion occurring in the combustion gas is eliminated, thereby reducing the generation of environmental pollutants. In particular, if the outlet temperature of the combustion chamber is maintained above 1100 ℃, it is also possible to incinerate certain solid wastes which can only be incinerated at incinerators for expensive industrial wastes.

The combustion air supply system has a problem in that the auxiliary burner 11, which is an auxiliary combustion device, needs to be frequently used because it is difficult to maintain a high temperature combustion chamber temperature because the calorific value is low in the case of incineration of general household waste.

In order to solve this problem, the drawing 2 is distinguished from the conventional incinerator drawing 1 through the use of a fixed water-cooled grate 101 and the suction of air 111 on the surface of the primary combustion chamber through the secondary combustion chamber combustion air blower 103. It is used as the combustion air 104 of the secondary combustion chamber, and the high temperature combustion air which mixed the air 105 sucked from the secondary combustion chamber bypass duct 115 and the air 106 of the incinerator outside air is primary. By minimizing the internal heat loss of the primary combustion chamber using the air blower 107 for the combustion of the combustion chamber.

Description of the grate

: The fixed grate 101 which minimizes the wear erosion corrosion between grates by fixing the surface of the grate to which waste is moved, and extends the life of the grate, is a water cooling structure in which boiler circulation water flows along the cooling lines 201, 202, and 203. Maintain a constant low temperature grate surface temperature regardless of the high temperature inside the combustion chamber. If the surface of the grate is similar to the temperature of the boiler water, the tensile strength of the metal is not unreasonable, and the performance is maintained only with ordinary carbon steel without using expensive superalloy like conventional mobile air-cooled grate. In addition, the combustion chamber temperature of 1000 ° C or more is not restricted, thereby maintaining the high temperature in the combustion chamber at all times, thereby eliminating incomplete combustion in the combustion gas. In particular, if the outlet temperature of the combustion chamber is maintained above 1100 ℃, it is also possible to incinerate certain solid wastes which can only be incinerated at incinerators for expensive industrial wastes.

Description of Combustion Air Supply System

: Due to the low calorific value of ordinary household wastes, the use of auxiliary burners (10) and over-use of auxiliary fuels are inevitable when incinerated. However, when using high-temperature combustion air, the amount can be minimized. Normally, the temperature of the combustion air in the combustion chamber is about 80 ° C, and the mixed air 107 of the combustion gas (about 800 ° C) and normal temperature air (25 ° C) in the combustion chamber bypass duct is about 200 ° C. Air (4) is a much higher calorific value combustion air than the temperature of 30 ° C. The combustion air supply system of the present invention minimizes the use of auxiliary fuel by using the combustion air 108 and maximizes heat accumulation in the combustion chamber.

When applying a fixed water-cooled grate, which can overcome the cooling and mechanical limits of the conventional mobile air-cooled grate, it is possible to make a grate using low-cost materials and to minimize the wear, erosion and corrosion of the grate being moved. In addition, high-temperature pyrolysis of 1200 ° C. or higher can be performed in a grate incinerator, so that not only general waste but also industrial waste having high calorific value can be incinerated. This can replace expensive rotary kiln incinerators. By maintaining the state of the incinerator at a high temperature, it is possible to realize the minimization of contaminants by realizing the complete combustion, and have an energy saving effect by absorbing the heat loss in the combustion chamber by the grate to send to the boiler.

When applying a combustion air supply system using high temperature combustion air, the heat loss in the combustion chamber can be minimized, and the temperature in the combustion chamber is controlled by using the high temperature combustion air as the temperature in the combustion chamber when the low calorific value waste flows. It is possible to reduce the amount of auxiliary fuel used to increase the amount, and by using a portion of the combustion chamber outlet gas of the secondary combustion chamber as the air for combustion, it is possible to achieve complete combustion of the unburned and incomplete combustion gas.

Claims (3)

A fixed water-cooled grate 101 is used to cool the grate as the boiler water, combustion air 103 and 104 is used as the air 111 on the surface of the combustion chamber, and the combustion chamber high temperature combustion gas 105 and the outside air 106 are mixed. Fixed water-cooled grate incinerator using one air (107) as combustion air (108). The combustion air (108) of claim 1, wherein the combustion air (103, 104) is used as the air (111) on the surface of the combustion chamber, and the air (107) in which the combustion gas (105) and the external air (106) of the combustion chamber is mixed is heated. Fixed water-cooled grate incinerators used as). 3. The stationary water-cooled grate incinerator of claim 2, cooled as boiler water and free of movement in the incinerator as grate.

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