KR100267146B1 - Combustion controlling method and dioxin removal method of stoker incinerator - Google Patents

Abstract

PURPOSE: A method for controlling combustion and a method for removing dioxin in a stoker incinerator is provided to control the density of oxygen and the fluctuation of displacement and to prevent exhaust of unburned gas. CONSTITUTION: A method for burning refuse in a stoker incinerator uses an automatic controlling system comprising a measuring equipment including a detecting sensor for temperature, density of oxygen, brightness, quantity of input of refuse, and thickness and a control device(19) adjusting temperature, the drive speed of grate, the feed rate of air, or the feed rate of refuse and then keeping the detecting value as the preset value according to the signal of power pulse. The exhaust gas caused by combustion is fed to the temperature-sensing tower and cooled instantaneously and then treated with adsorbent.

Description

COMBUSTION CONTROLLING METHOD AND DIOXIN REMOVAL METHOD OF STOKER INCINERATOR

The present invention relates to the combustion control of the stocker incinerator and the suppression of the generation of dioxin, and is a method of combusting by injecting air from the bottom of the grate by supplying waste on the heat-resistant casting grate in the stocker.

In the municipal waste incineration process, a mechanical stocker is used to stir and transport the waste in the furnace.

The furnace is composed of a drying zone (Zoon), a combustion zone and a post-combustion zone. The waste receives heat from the combustion gas on the stocker, and combustion occurs in stages such as drying, combustion, and post-combustion.

Combustion is mainly carried out in the combustion zone (Zoon), and depending on the quality of the waste or incineration, it is also burned in the drying zone, and incineration is completed in the post combustion zone.

The size of the trash should be incinerated below the hopper inlet size, and the upper limit of the low calorific value of the waste (Hu = 3,500 kcal / kg, d) and the natural limit (Hu = 800 kcal / kg, d).

Incineration residues and incombustibles are discharged and cooled by the reloading unit in the lower part of the furnace.

Conventional stocker incinerators incinerate municipal waste or other incinerators to continuously throw waste into the stocker.

At this time, urban garbage was entangled with each other in large quantities and was introduced in large quantities.

Stalker incinerators have the disadvantage of slow combustion and poor combustion.

In other words, since the combustion performance is not good, the incineration may be burned for several hours later.

Therefore, when urban waste is injected, if the feeder fed into the furnace is badly or largely instantaneously introduced in large quantities, it is connected to the oxygen concentration imbalance in the combustion gas, resulting in unburned gas such as carbon monoxide, propylene, ethylene, Acetylene, methane, benzene and hydrocarbons are emitted.

Therefore, substances such as Hcl, SO _x , NO _x and Dioxin are generated and discharged from the stack.

In addition, the stocker incinerator has a slower combustion performance than the fluidized bed furnace, so the amount of air blown into the lower part of the roaster is excessive and the roaster must be continuously driven.

In addition, considering that the waste feed feeder is not quantitatively supplied, surplus air may be blown in advance so that the oxygen concentration does not decrease even when the amount of incineration is increased. Also used.

However, even in this case, when the garbage is entangled and introduced into a large mass, it becomes momentarily oxygen deficient and does not function in the drying roaster, and the waste introduced into the combustion zone is deficient in oxygen and unburned gas such as carbon monoxide is discharged from the stack. Sometimes.

In order to prevent the discharge of these unburned gases, the feed feeder is improved to improve the quantitativeity of the feed feeder for supplying the incineration to the furnace, or a metering device for measuring the amount of incineration or waste input is installed. When a large amount was entered, the feed feeder was stopped and the operation of the drying roaster was stopped to reduce the amount of waste flowing into the combustion zone.

However, the apparatus for improving the quantitative property in the use of the feed feeder, which is one of the methods for preventing the unburned gas discharge in the related art, has limitations and costs more than its performance.

Incinerators introduced into the furnace are stagnant in the drying zone and are introduced into the combustion zone by the input amount.

As new secondary air is introduced to replenish this oxygen, the exhaust gas increases.

As the amount of exhaust gas increases, it requires large-capacity such as exhaust duct, gas cooler, dust collector, and noxious gas treatment equipment to meet the large amount of exhaust gas. The week had a problem.

The present invention aims to provide a method that can economically and stably treat wastes by designing various equipments designed for the amount of excess exhaust gas to an appropriate level, drastically reducing the excess facilities, and reducing construction and operation costs.

1 is an installation state of the automatic combustion control device of the present invention.

Figure 2 is a dioxin treatment system of the present invention.

3 is a measurement result diagram showing changes in oxygen concentration, contrast and air amount in the case of combustion control by the method of the present invention.

Figure 4 is a view showing the results of the dioxins removal rate of the present invention.

5 is a view showing the results of the furnace temperature distribution of the present invention.

Figure 6 is a view showing the results of each process dioxin removal of the present invention.

* Explanation of symbols for the main parts of the drawings

1, 2, 3: Garbage thickness measurement detection sensor 4: Contrast measurement detection sensor

5: Temperature measurement detection sensor 6: Oxygen concentration detection sensor

7: Input quantity measurement detection sensor 8: Input hopper

9: feeder 10: drying stocker

11: combustion stocker 12: after combustion stocker

13: exhaust duct 14: stack

15: manned blower 16: blower

17, 18: measuring device 19: control device

22: Incinerator 23: Thermal Tower

24: dust collector 25: adsorption tower

26: washing tower 27: manned blower

28: stack 29: preparation and input of activated carbon

30: spray

Figure 1 is for the automatic combustion control device of the present invention after measuring the input amount in the input waste detection sensor 7 for detecting the amount of waste injected into the input hopper (8) the waste flowing into the drying stocker 10 from the bottom After drying with blowing hot air, it flows into the combustion stocker (11).

At this time, the drying stocker 10 is a partial device of the incinerator to dry uniformly and quickly the waste introduced from the radical machine.

The preheated air at the bottom of the roaster evaporates moisture as it passes through the waste bed.

In addition, the combustion stocker 11 is a device that promotes combustion under optimum conditions by operating a roaster to invert, agitate, and vent the waste in order to uniformly and rapidly burn the waste introduced from the drying stocker 10.

It burns more than 90% in the combustion stocker 11 and the remainder is sent to the post combustion stocker 12.

At this time, the post-combustion stocker 12 is a device having a function of completing combustion with the function of the main combustion stocker or the incineration of waste which is difficult to burn or waste which requires a long time for combustion.

The post combustion stocker 12 has a combustion complete function together with the function of the combustion stocker 11.

At this time, the garbage thickness detection sensor (1) (2) (3) and the contrast measurement detection sensor (4), the temperature measurement detection sensor (5) and the oxygen concentration detection sensor (10) (11) and (12) installed in each stocker (10) (11) (12) 6) is determined according to the signal applied from the interface that outputs the power pulse signal from the control device 19 by the microcomputer control processing in accordance with the measured value and the control device 17 and 18 according to the measured value The control system of the roaster driving cylinder and the blower (16) increases or decreases the operation of the optimum combustion and automatic combustion control;

The manual mode selection step for manual operation is performed, and the remaining exhaust gas is discharged to the stack 4 by the induced blower 15 below the environmental standard value through the dioxins and exhaust gas treatment facilities of FIG. 2.

Incineration wastes include Hcl, So _x , NO _x , Dioxin and heavy metals.

It is a facility for discharging this under the environmental regulations.

Pretreatment → Stalker Incineration → Hazardous Gas Treatment

The characteristics of the combustion control method of the present invention are the oxygen concentration in the exhaust gas, the furnace contrast and various methods are used, but the present invention was invented to solve the problem of the conventional stocker by measuring the thickness of the waste. The detection means of the measurement detection sensor 6, the detection means of the in-contrast contrast detection detection sensor 4, and the garbage thickness measurement detection sensors 1, 2, 3, etc. simultaneously detect the state in the furnace and control combustion at optimum conditions. That's how.

At this time, the furnace temperature measurement detection sensor (5), contrast measurement detection sensor (4), oxygen concentration measurement detection sensor (6). The opening degree of each control valve is determined by the power pulse signal value applied from the interface which outputs the power pulse signal of the microcomputer which controls according to the detection value of the garbage thickness measurement detection sensor (1) (2) (3). Output to open up to.

The present invention measures the amount of garbage supplied to the incinerator chute, which supplies the municipal waste for incineration to the stocker incinerator, by measuring the amount of waste supplied by the apparatus 17 and 18, thereby measuring the combustion state of the furnace and the amount of waste accumulated on the stocker. Can be controlled in optimum conditions.

In particular, when the signal of the supply amount measuring device in the waste chute exceeds a predetermined input amount, the primary feeder is immediately stopped and the constant air amount dry roaster driving device supplied to the secondary drying stocker is controlled.

The combustion can be controlled quickly by supplying the drive device of the tertiary combustion stocker and the air corresponding to the combustion.

A photoelectric element that detects a waste supply amount in a waste chute is a transmissive photoelectric sensor configured from a light emitting portion and a light receiving portion.

In this photoelectric sensor, the amount of waste supplied is measured in an instant according to the detection signal.

In this case, by controlling the microcomputer to measure the supply amount every second and control according to the value, it adjusts the feeder supply amount according to the power pulse signal value applied from the interface that outputs the power pulse signal and safely controls the combustion state in the furnace. .

FIG. 2 relates to a dioxin treatment system, and minimizing the generation of dioxins in the exhaust gas according to municipal waste incineration can minimize the occurrence of only a good combustion method.

The exhaust gas discharged from the stocker incinerator 22 is cooled in the temperature reduction column 23 in the range of 150 ° C to 200 ° C.

Thermal exhaust gas no longer produces dioxins.

At this time, in order to remove dioxin and heavy metals generated in a small amount in the exhaust gas, activated carbon and a preparation 29 are added and removed by adsorption, and then collected by a dust collector 24, and then passed through an adsorption tower 25 or an oxidation catalyst tower 26 as it is. Inflow to the discharged to the stack 28 by the attraction blower (27).

An embodiment of this invention will be described according to the accompanying schematic diagram.

Stalker incinerators are suitably designed according to their incineration targets, and if the objects are all urban debris, a systematic first approach, such as fractionation, should be taken from the emitter stage.

The waste thus discharged is collected and transported to a waste pit, and then crushed again by a crusher or the like, and a pretreatment facility for sorting non-combustibles and feeding the remaining trash into a transport stocker incinerator is required.

The present invention aims to reduce dioxin discharged from incinerators. The conventional treatment method is a temporary method of improving incineration or combustion, or injecting a compound containing sulfur into the furnace to suppress generation.

Subsequent methods include the injection of slaked lime and activated carbon, the denitrification by catalytic reduction and the simultaneous removal of dioxins.

This method is not only expensive in terms of facility costs, but also excessively expensive operation and management costs, which is a huge financial burden.

The main point of the present invention is a highly automatic combustion control method considering dioxin suppression, that is, a low temperature dust collection method using purge control, which cools the gas to 200 ° C. or lower in the temperature reduction tower.

In this case, the high pressure spray nozzle is used to atomize the liquid and instantaneously cool and dry.

At this time, the particle size of the particles sprayed from the nozzle is 100㎛ or less and the water pressure is 200kg / cm ² or more.

The hot exhaust gas is cooled to 200 ° C to 150 ° C in 1 second while dioxins are suppressed by 95% or more.

At this time, special preparation and a small amount of activated carbon were added to the dust collector inlet to remove and adsorb dioxins and heavy metals up to 99.5%.

After combustion control in accordance with the method of the present invention, the measurement results according to the dioxin removal method are as follows.

Item Measures In-house residence time (Sec) 0.4-0.5 Outlet temperature in furnace (℃) 900-1,000 Thermal Tower Inlet Temperature (℃) 720-850 Thermal Tower Outlet Temperature (℃) 130-150 Dioxin average concentration (ppm) 12-20 Dioxin peak production concentration (ppm) 22-35 Back filter inlet dioxin concentration (ppm) 22-28 Backfutter Exit Dioxin Concentration 0.056-0.073 Dioxin removal rate (%) 99.8

As described above, in the stocker incinerator according to the present invention, the combustion control method and the dioxin removal method can suppress the fluctuations in the oxygen concentration and the exhaust gas amount in the exhaust gas even if the amount of the incineration material injected into the stocker incinerator is varied. Since the discharge can be prevented, it is effective as a combustion control method in an incineration facility having a stocker incinerator.

It is easy to control stable incineration when urban wastes of incinerators with different calorific value or different in nature, shape, and volume of combustion are used as incinerators for combustion. In this way, it is beneficial to the public health life and to reduce the national finance.

Claims (4)

In the waste combustion treatment in the stocker incinerator which injects air to perform drying, combustion and post combustion of the waste, (A) an interface for outputting a power pulse signal under (1) temperature, oxygen concentration, contrast, waste input and waste thickness detection sensors, and (2) microprocess control corresponding to the detected value of the measurement apparatus. Using an automatic control system consisting of a control device for adjusting the temperature, the roaster driving speed, the air supply amount or the waste supply amount according to the power pulse signal value applied from to maintain the detection value at each preset value, (B) transferring the exhaust gas generated during combustion to a temperature-sensitive tower, cooling it to 150 to 200 ° C within one second, and then treating it with an adsorbent. How to dispose of waste in stalker incinerators. The method of claim 1, A waste thickness detection sensor is mounted on each of the drying, combustion and afterburner stockers. The method of claim 1, The waste input quantity detection sensor is a transmissive photoelectric sensor comprising a light emitting part and a light receiving part. The method of claim 1, The instantaneous cooling of the exhaust gas is achieved by the fine particles injected from the high pressure spray nozzle.