JP4660525B2 - Cremation furnace exhaust control method and system - Google Patents

Description

  The present invention relates to a cremation furnace exhaust control method and system.

  In recent years, the crematorium has been developed as a modern, pollution-free facility that wipes out the traditional image. In particular, the cremation furnace, which is the main equipment, is required to have a performance that does not emit smoke and does not generate odors. Furthermore, the emission of dioxins is required to be less than a certain value, similar to a waste incinerator. .

  The cremation furnace is a very unique combustion device that performs two processes in one furnace, the self-combustion process in the first half of the cremation and the direct incineration in the second half. In addition, the intermittent operation is unique.

FIG. 1 is a schematic diagram illustrating a standard cremation process. In the figure, 1 is a cooling chamber, 2 is a main combustion furnace, 3 is a trolley inside the furnace, 4 is a gutter, 5 is a gantry, and 6 is a remains.
Cremation has the following characteristics from the viewpoint of burning the body.

(1) In the first half of the cremation, there is a large amount of flammable substances such as spears, side funerals, and dead body fat, and after firing the burner due to the effect of ceramic fiber on the main combustion furnace wall, Abrupt combustion occurs, and a large amount of combustion gas is temporarily generated. Combustion at this time is mainly self-combustion, and the supply amount control of the combustion air and the furnace pressure control are important factors. At this stage, it is important not to make the combustion runaway. The point of cremation furnace control is determined by how this part is optimally performed.

(2) In the second half of the cremation, a relatively small amount of non-combustible material with a high water content centering on the abdomen of the corpse is burned with a burner flame. Combustion during this period is mainly direct incineration by the burner flame, and maintaining the high temperature and promptly renewing the combustion surface of the combusted material are important points.

  Therefore, advanced technology is required to operate the cremation furnace automatically and optimally.

  In the era when there was no automatic operation system, each device performed single-loop control for individual control factors. In this case, when trying to operate the furnace in an optimal state, especially in the first half of the cremation, Had to stick to the furnace. That is, it is necessary to monitor the combustion state and manually adjust the output of each burner.

  In addition, the furnace pressure control is always torn in preparation for the case of abnormal combustion because the burning rate increases too much when there are many combustibles such as collaterals or when the fat content of the corpse is high. It was necessary to make it negative. As a result, even when the burned material in the second half of the cremation decreases or even in the first half of the cremation, the heat generated when the calorific value of the burned material is relatively low cannot be fully utilized, and the main combustion furnace, Both the combustion furnaces were in a situation where the temperature was difficult to rise, and burners were burned using waste fuel to maintain the temperature.

Next, FIG. 2 shows the configuration of a current general cremation furnace combustion control system.
In FIG. 2, 1, 1 'is a cooling chamber, 2, 2' is a main combustion furnace, 7, 7 'is a recombustion furnace, 8, 8' is a cooler, 9, 9 'is a furnace outlet damper, and 10 is a bug. A filter, 11 is a catalyst, 12 is an induction blower, and 13 is an exhaust pipe. In this cremation furnace combustion control system, two systems of cooling chambers 1, 1 'to furnace outlet dampers 9, 9' are provided, and a common bag filter 10 to an exhaust pipe 13 are provided. The system can be used.

  In this combustion control system, a recombustion furnace 7, 7 ', a bag filter 10, a dioxin decomposition catalyst 11 and the like are attached to the cremation furnace in order to prevent the emission of malodors and dioxins.

  In this way, by providing one (common) bag filter 10 to the exhaust pipe 13 for a plurality of cremation furnaces, the structure of the entire cremation ground is simplified and the equipment cost is reduced.

  In such cremation furnaces of a plurality of systems, conventionally, the rotational speed of the induction blower 12 is made constant, and the gas discharge amount is adjusted by adjusting the opening degree of the furnace outlet damper of each cremation furnace. Therefore, the rotation speed of the exhaust fan is set according to the case where the entire cremation furnace is operated and the exhaust temperature is highest, that is, when the damper of the outside air intake is the most open, and only a single cremation furnace is used. When operating, there has been a problem that the amount of gas discharged becomes excessive, leading to a decrease in the internal temperature of the cremation furnace, waste of fuel gas, and air pollution.

  In order to solve such a problem, Patent Document 1 includes sub-exhaust pipes that communicate with a plurality of cremation furnaces, and exhausts gas from the exhaust pipe via the main exhaust pipe that communicates with each sub-exhaust pipe. In the exhaust device of the cremation furnace, an external air intake with an intake damper is provided in the main exhaust pipe, and the cremation furnace and the exhaust pipe leading to the cremation furnace are provided between the external air intake and the exhaust pipe of the main exhaust pipe. The temperature of the gas flowing into the main exhaust pipe from the cremation furnace was adjusted by controlling the opening degree of the intake damper at the outside air intake, and the outside air was deviated from the appropriate value by taking in outside air through an exhaust fan that sucks and discharges gas from the inside. The pressure inside the pipe is adjusted to be an appropriate value by controlling the rotational speed of the exhaust fan and the opening of the pressure regulating damper in the pipe, and further, depending on the intake of the outside air, the number of operating the cremation furnace and its combustion state, The internal pressure of each cremation furnace that changes every moment Exhaust device is disclosed that can be adjusted by control of the opening degree of the furnace pressure control damper.

JP-A-8-28832

  However, in the cremation furnace exhaust apparatus disclosed in the above-mentioned Patent Document 1, an appropriate amount of outside air is taken into the main exhaust pipe according to the temperature of the gas flowing through the main exhaust pipe, and the rotational speed of the exhaust fan or the main exhaust pipe It controls the opening degree of the in-pipe adjustment damper installed in the pipe, and the control when multiple cremation furnaces are operating becomes complicated, and the fluctuation of the pressure of one cremation furnace becomes the pressure of the other cremation furnace. There exists a problem that it is easy to give influence and that reliable pressure control is difficult.

  Therefore, the present invention, when exhausting a plurality of cremation furnaces through a common induction blower, exhaust pipe, the pressure fluctuation of a specific cremation furnace is less likely to affect the pressure fluctuation of other cremation furnaces, It is an object of the present invention to provide a cremation furnace exhaust control method and system that can simplify the control of each cremation furnace.

In order to solve the above-mentioned problems, a first configuration of the present invention is a main combustion burner and a main combustion furnace secondary for burning a firewood placed on an in-furnace trolley, a corpse housed therein, a subsidiary funeral, and the like. A main combustion furnace provided with an air quantity damper, a recombustion furnace provided in communication with the main combustion furnace, provided with a reburn burner and a secondary air quantity damper, and an exhaust from the recombustion furnace are cooled. A plurality of cremation furnaces comprising a cooler that cools and a furnace outlet damper provided at an outlet of the cooler, and the exhaust from each of the recombustion furnaces of the plurality of cremation furnaces is gathered into one system and attracted An exhaust control method for a cremation furnace comprising an induction blower and an exhaust pipe for discharging exhaust gas induced by the induction blower to the atmosphere, and a plurality of control computers for controlling each of the cremation furnaces Installed and set the furnace pressure inside the cremation furnace The control computer having jurisdiction over the higher cremation furnace controls the induction blower so that the furnace pressure of the cremation furnace with the higher furnace pressure is maintained at the set pressure, and another control computer Thus, the opening degree of the furnace outlet damper of the own cremation furnace is controlled so that the pressure in the furnace of the cremation furnace managed by the person becomes a predetermined pressure.
In addition, the second configuration of the present invention is provided with a main combustion burner and a main combustion furnace secondary air amount damper for burning the firewood placed on the in-furnace carriage, the body, the burial goods, etc. A main combustion furnace, a recombustion furnace installed in communication with the main combustion furnace and provided with a reburn burner and a reburning furnace secondary air amount damper, a cooler for cooling the exhaust from the reburning furnace, A plurality of cremation furnaces comprising a furnace outlet damper provided at an outlet of the cooler, an induction blower that attracts and collects exhaust from each of the reburning furnaces of the plurality of cremation furnaces in one system; and An exhaust control system for a cremation furnace comprising an exhaust pipe for exhausting exhaust gas induced by an induction blower to the atmosphere, wherein a plurality of control computers for controlling each of the cremation furnaces are installed, and the cremation Among the furnaces, the fire whose furnace pressure is higher than the set furnace pressure The induction blower is controlled by a control computer having jurisdiction over the furnace so that the furnace pressure of the cremation furnace having the higher furnace pressure is maintained at the set pressure. It has a means for controlling the opening degree of the furnace outlet damper of its own cremation furnace so that the pressure inside the cremation furnace under its jurisdiction becomes a predetermined pressure.
In the present invention, among the control computers that control a plurality of cremation furnaces, the control computer that controls the cremation furnace whose furnace pressure is higher than the set pressure has the right to operate the induction fan, The induction fan is controlled so that the internal pressure becomes the set pressure. If this is done, the pressure in the furnace of the other cremation furnace will be excessively pulled as it is, so the control computer will adjust the furnace pressure of its own cremation furnace so that the pressure in the furnace of the cremation furnace under its control becomes a predetermined pressure. Controls the opening of the outlet damper. Thereby, the division of roles of the operation of each control computer is clarified, and stable computer control is possible for the cremation furnace.
By connecting the control computers to each other and enabling the switching of the operation right of the induction fan, it is possible to transfer the operation right for a specific cremation furnace that is performing a process that requires precise control, Further, when a specific control computer goes down, another control computer can supplement the control.
The control computer enables fine pressure control by setting the target value of the furnace pressure in a plurality of stages in accordance with the progress of the cremation process from the ignition of the main combustion burner.

  According to the present invention, a control computer for controlling each cremation furnace is installed, and one of the control computers has a furnace pressure in the cremation furnace controlled by the control computer at a set pressure. The control computer has a means for controlling the induction blower to be maintained, and the other control computer opens the furnace outlet damper of its own cremation furnace so that the pressure inside the cremation furnace under its control becomes a predetermined pressure. The degree of pressure fluctuation of a specific cremation furnace affects the pressure fluctuation of other cremation furnaces when exhausting multiple cremation furnaces through a common induction blower and exhaust stack. And the control of each cremation furnace can be simplified.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In order to perform automatic operation efficiently, it is necessary to make the furnace suitable for computer control while maintaining the performance of each equipment of the furnace. For this purpose, various ideas not available in other cremation furnaces are given below.

FIG. 3 shows the situation in the main combustion furnace in (a) the first half of the cremation and (b) the second half of the cremation.
Immediately before the cremation ignition, as shown in FIG. 3A, the soot 4 occupies about 80% of the volume of the main combustion furnace 2, and the volume of the combusted material gradually decreases after ignition. In this case, the insufficient combustion air is supplemented by the leaked air that enters the furnace through the space between the in-furnace carriage 3 and the side wall and the secondary air. If there are many collaterals in 柩 4 or if the body is high in fat, excessive use of secondary air will cause excessive combustion and control the amount of secondary air so that combustion does not run away It is necessary. The amount of leaked air is inversely proportional to the furnace pressure, but the main combustion furnace 2 must always be kept at a negative pressure so that high-temperature combustion gas does not enter the lower part of the furnace carriage 3, so it always leaks into the main combustion furnace. Air has been introduced.

  In the second half of the cremation, as shown in FIG. 3 (b), a so-called flame-retardant portion having a large amount of moisture centered on the abdomen of the body is incinerated by the flame of the main burner 14. The surface of the flame retardant part is carbonized by the heat of the flame of the main combustion burner 14 and is covered with a carbon film. In such a state, since the thermal conductivity of the carbon covering the outside is small and the diffusion of oxygen is blocked by the carbon coating, it becomes a situation where combustion is further difficult. The key to promoting the combustion of the flame retardant is to burn the carbon film on the surface well.

for that purpose,
(1) Efficient supply of heat to raise the temperature of the flame retardant part,
(2) Efficient supply of air (oxygen) for flame retardant combustion
is required.
In (1), it is necessary to maintain the high temperature of 1000 ° C or higher in order to efficiently burn the carbon on the front as well as to supply the heat of evaporation of water well (Edited by the National Council of Air Pollution: Air Pollution) (See Handbook (3), Combustion, Corona (1973)).
In order to realize this, the frame 5 is used to float about 10 cm from the in-furnace carriage 3, and the flame retardant part of the corpse B is encased in the flame of the main combustion burner 14. Moreover, in order to implement | achieve (2), high-speed air is blown toward the flame-retardant part of the corpse B from the secondary air port of a furnace wall.

  The amount of exhaust gas discharged from the main combustion furnace 2 is not uniform, particularly in the first half of the cremation, and is discharged in an incompletely burned state. In order to completely burn this, a recombustion furnace 7 is installed following the main combustion furnace 2 as shown in FIG. The reburning furnace 7 is provided with a reburning burner 15 for raising the temperature and maintaining the temperature, and a secondary air inlet 16 for maintaining the oxygen concentration is provided at the lower part of the reburning burner 15. The recombustion furnace 7 requires good mixing properties and sufficient gas residence time, but as shown in FIGS. 4B and 4C, suitable throttles 17 and 18 are provided in the furnace. By this, the mixing property of combustion gas and secondary air is ensured. These mixing characteristics are based on the research by Kenji Fujiwara et al. “Development of a garbage combustion model for a batch incinerator” (Kenfuji Fujiwara, Junji Suzuki, Nobuo Takeda, Masateru Takaoka, Masaji Eguchi: Development of a garbage combustion model for a batch incinerator. , The journal “EICA”, Vol. 7, No. 2, 93-96 (2002)). The capacity of the recombustion furnace 7 is set such that the residence time of the combustion gas is secured for 2 seconds or more with respect to the maximum exhaust gas amount. Since the recombustion furnace 7 is installed following the main combustion furnace 2, the furnace pressure controllability of the main combustion furnace 2 depends on the response characteristics of the recombustion furnace 7 with respect to fluctuations in the internal pressure of the furnace. When the pressure loss of the recombustion furnace 7 is large, the response characteristics are also lowered. Therefore, a structure with a relatively small pressure loss is maintained while maintaining the mixing characteristics, and a structure as shown in FIG. 4 is adopted.

A system that supplies oxygen, that is, air, which is one of the three elements of combustion, is an important factor in burning an object.
As a method of adjusting the amount of air freely, as shown in FIG. 5, a system using a combustion blower 20 and control dampers 21 a to 21 d is constructed, and an inverter 23 is used to make the air pressure in the header 22 constant. The rotational speed control of the combustion blower 20 is performed. By measuring the header pressure of the blower 20 for combustion with a pressure gauge 24 provided in the header 22 and controlling the control dampers 21a to 21d of each line with a regulator 25, the air for the main combustion burner and the secondary for the main combustion furnace Air, reburn burner air, and reburn furnace secondary air can be freely supplied.

Control of the furnace pressure is extremely important for the furnace, and it is no exaggeration to say that the quality of the furnace pressure determines the performance of the furnace.
If the pressure inside the furnace is not well controlled (1) When pulling is not enough • Combustion gas blows out of the furnace.
-Combustion gas will travel to the bottom of the furnace truck and damage the wheels of the furnace truck.
(2) When the pull is too large ・ A large amount of external leak air enters the furnace and the furnace temperature is unlikely to rise.
In the case of (2), the fuel consumption for maintaining the furnace temperature increases, resulting in an increase in the amount of exhaust gas, which is not preferable from the viewpoint of energy saving.
As shown in FIG. 6, the furnace pressure is controlled by a furnace outlet damper 9, 9 ′ and an induction fan 12. In this method, a pressure signal of each recombustion furnace 7, 7 ′ is sent to the regulator 26, and the internal pressure of the furnace is controlled by controlling the rotational speed of the induction blower 12 and the furnace outlet dampers 9, 9 ′.

  As shown in FIG. 7, the burners (the main burner 14 and the reburn burner 15) are systems in which the control dampers 29 a and 29 b separately control the amount of fuel (gas) and the amount of air by the regulator 28. As a result, the air-fuel ratio of the main burner 14 and the reburn burner 15 can be freely changed. As a result, the position of the highest temperature portion of the flame can be changed without moving the burners 14 and 15. . It is also possible to blow only air.

  FIG. 8 shows the configuration of a control system related to combustion. The control computer 30 has six measurement signal inputs and six operation signal outputs. In the present embodiment, the measurement signals are the main combustion furnace thermometer 31, the furnace pressure gauge 32, the recombustion furnace thermometer 33, the recombustion furnace outlet thermometer 34, the oxygen concentration meter 35, and the flue gas concentration meter 36. The signals are the main combustion furnace secondary air quantity damper 37, the main combustion furnace burner output 38, the recombustion furnace secondary air quantity damper 39, the recombustion furnace burner output 40, the furnace outlet damper 41, and the induction fan rotational speed 42. As an interface with the operation side, an operation panel touch panel 43 such as a liquid crystal display is adopted so that each data can be displayed and the operation state of each device can be displayed, and each device can be manually operated. .

<Control configuration>
The configuration of the control is as shown in FIG. 9, and the main control is accompanied by six sub-controls, and is linked to each other through empirical control. The sub-controls of this embodiment are main combustion furnace temperature control, recombustion furnace temperature control, furnace pressure control, recombustion furnace oxygen concentration control, flue gas concentration control, and combustion acceleration control.

(1) Main control Main control is that the original purpose of the cremation furnace is to incinerate the body and quickly burn it, so the value of the flue gas concentration meter 36 is kept at 0 and the oxygen concentration is 6%. While maintaining the above (at least about 3% at the beginning of cremation), the output of the main burner 14 is maximized quickly.

(2) Main Combustion Furnace Temperature Control As shown in FIG. 10, the main combustion furnace temperature control is performed by taking the signal of the main combustion furnace thermometer 31 into the control computer 30, and outputting the main combustion burner 14 and the main combustion. Although the amount of secondary air in the furnace is changed, the main operation is the output of the main combustion burner 14. That is, if the furnace temperature is low, the output of the main combustion burner 14 is increased, and if the furnace temperature is high, the output of the main combustion burner 14 is decreased. However, in this control method, in the first half of the cremation, a large amount of combustibles are present in the main combustion furnace 2, so that the main combustion burner 14 is kept to a minimum or extinguished state. The operation of the secondary air amount is important. When the main combustion furnace secondary air is introduced in the first half of the cremation, the temperature of the main combustion furnace 2 generally tends to rise, but in reality, the calorific value of the combusted material and the timing of the introduction of the main combustion furnace secondary air Depending on the amount, it may descend. At this point, it must be absolutely avoided that the combustion runaway and become completely untouched. This is because it is a corpse that is burning, and it is not possible to take measures such as adding water to slow down the burning. As a solution, control based on empirical rules is added, and main combustion furnace temperature control is performed within a target temperature range (approximately 800 ° C. to 1100 ° C.). Here, the control logic is configured based on an empirical rule that “if the temperature rises when the secondary air is blown, the calorific value of the combusted material is high, and if it falls, the calorific value is low”. . That is, first, if the temperature condition is satisfied in the latter half of the first half of the cremation, the secondary air damper is opened for a certain time by X%. At this time, if it is within the range of the target temperature, the target operation is repeated, and if not, this operation is stopped. Here, the time, temperature condition, and target temperature are values determined by experience, and when the calorific value of the combusted material is large, the secondary output is in the minimum output of the main combustion burner 14 or in the fire extinguishing state. Good combustion can be performed only with air.
Of course, when the calorific value of the combusted material is small, the output of the main combustion burner 14 is increased, and the control for maintaining the combustion works.

(3) Recombustion furnace temperature control FIG. 11 shows a recombustion furnace temperature control system. The temperature control of the reburning furnace 7 is mainly performed by taking the signal of the reburning furnace outlet thermometer 34 or the reburning furnace thermometer 33 into the control computer 30 and changing the output of the reburning burner 15. If the temperature of the reburning furnace 7 does not reach the target temperature, the output of the reburning burner 15 is increased. Conversely, when the temperature of the reburning furnace 7 rises too much, first, the reburning burner 15 is extinguished. For example, the blowing amount of the recombustion furnace secondary air is increased, and if it is still insufficient, only air is supplied from the reburning burner 15. The amount of secondary air in the reburning furnace and the amount of air from the reburning burner 15 can be freely controlled by the damper 21a with a control motor. Here, empirical rules are used for the timing of extinguishing the reburning burner 15 and the usage of the two thermometers 33 and 34 installed in the reburning furnace 7.

  In cremation, since the amount of combustibles decreases, the amount of exhaust gas also decreases accordingly, so it is not possible to use a reburning furnace designed for the maximum gas amount from the beginning to the end in the same state. It is an economy.

Therefore, the following control is performed.
(A) First half of cremation-A recombustion furnace outlet thermometer 34 installed at the upper stage of the recombustion furnace 7 is used as a thermometer for measuring the temperature representative of the recombustion furnace.
-Set the reburning burner 15 to an ignition state.

(B) The second half of the cremation-As the thermometer for measuring the temperature representative of the reburning furnace 7, a reburning furnace thermometer 33 installed in the middle stage of the reburning furnace 7 is used.
-Extinguish the reburn burner 15.
The problem here is the determination of the first half and the second half of the cremation, and rules of thumb are used for this judgment. Determine whether the main combustion furnace is incineration centered on the main combustion burner 14 by the cremation time, main combustion burner output, main combustion furnace secondary air amount, and main combustion furnace temperature change rate. And the control of (b) is performed. Judgment standard values were all determined by empirical rules. This improvement has reduced fuel consumption.

(4) Furnace pressure control In the cremation system according to the embodiment of the present invention, as shown in FIG. 12, one induction blower 12 is provided for two cremation furnaces C and C ′. The control computers 30 and 30 ′ of the two cremation furnaces C and C ′ operate the induction blower 12 in cooperation with each other to control the pressure in the furnace. Of the two control computers 30 and 30 ′, one has the right to operate the induction fan 12. The two control computers 30 and 30 ′ communicate with each other to share information.

  The control method targets the higher one of the two cremation furnace internal pressures, for example, the cremation furnace C, and controls the induction blower 12 so that the set furnace pressure is maintained. If it carries out like this, a negative pressure will become large in the other cremation furnace C ', and will be in what is called an excessive pulling state. By closing the furnace outlet damper 9 'of the other cremation furnace C' until a predetermined pressure is reached, the set pressure is obtained. As shown in FIG. 13, the control computers 30 and 30 ′ are coupled to each other and can switch the operation right of the common part D (the induction fan 12), and one of the control computers is down. However, it is a duplex system in which the control can be complemented by the other control computer.

  The furnace pressure control is: “In the first half of the cremation, a large amount of combustion gas is generated abruptly, so it is better to make the furnace pressure slightly negative, and in the second half the main combustion furnace temperature is kept high with less fuel. In addition, it is better to reduce the negative pressure based on an empirical rule. Specifically, for example, “the pressure Y1 is set from the main burner ignition to the soot ignition confirmation”, and “the pressure Y2 is set from the soot ignition confirmation to less than Xi minutes”. The target value is set to 9 levels and changed according to the cremation process. Here, the values of Xi and Yi are values determined by empirical rules. This method also helps to reduce fuel consumption.

FIG. 14 is a flowchart illustrating an example of a furnace pressure control method using two control computers 30 and 30 ′. Each of the control computers 30 and 30 ′ exchanges data on the furnace pressures of the cremation furnaces C and C ′, which are under its control, as well as the furnace pressures of other cremation furnaces. When the control starts, in step S100, a cremation furnace having a higher furnace pressure (P _H ) is selected from the two cremation furnaces C and C ′. The pressure inside the other cremation furnace is P _L. In step S110, P _H is set pressure range (lower limit x _i, the upper limit y _{i: i} = 1~8) determines whether or not the product is within. If not on, when P _H is greater than y _i, in step 120, the pressure inside the furnace until cremation furnace P _H is P _H ≦ y _i, increase the rotational speed of the induced draft machine 12. If P _H is smaller than x _i as determined in step 110, the rotational speed of the induction fan 12 is decreased in step 130 until the cremation furnace having the furnace pressure P _H satisfies x _i ≦ P _H. Next, in step 140, it is determined whether the furnace pressure P _L of the other cremation furnace is smaller than x _i . If it is smaller, the process returns to step S100. If so, in step 160, the furnace outlet damper 9 or 9 'of the cremation furnace whose furnace pressure is P _L is adjusted so that x _i ≦ P _H. Then, it returns to step S100. If P _H is between x _i and y _i in the determination in step 110, the rotational speed of the induction fan 12 is not changed, and it is determined in step S150 whether P _L is greater than or equal to x _i . If so, the process returns to step 100. Otherwise, the process returns to step 100 after performing the process of step S160.

  In this way, the operation right of the induction fan 12 is given by the computer of the cremation furnace with the higher furnace pressure, and the opening of the furnace outlet damper of the cremation furnace with the lower furnace pressure is controlled by the other computer. By adjusting, when exhausting multiple cremation furnaces through a common induction blower and exhaust pipe, the pressure fluctuation of a specific cremation furnace is less likely to affect the pressure fluctuation of other cremation furnaces, Control of each cremation furnace can also be simplified.

(5) Smoke concentration control This control system is shown in FIG. The flue gas density is a value indicating the dust density as “light transmittance density (% OPACITY)” by installing a projector and a light receiver facing the flue, calculating the attenuation of the measurement light. Control of flue gas concentration was the most important control that became the center of combustion control until an oximeter was installed in the reburning furnace. In the first place, an increase in dust concentration means that combustion gas is generated exceeding the processing capacity of the reburning furnace under the condition that the reburning furnace control system is functioning normally. In general, there are the following methods for reducing the dust concentration.

(A) The furnace pressure is used as a key. Leakage air in the main combustion furnace 2 increases and combustion air is supplied, so that incomplete combustion is eliminated.
(B) Reduce or turn off the output of the main burner 14. Reduce the amount of secondary air in the main combustion furnace.

  This control is based on heuristics. When the flue gas disappears in the stage (a), the amount of combustion gas is considered not to be so large with respect to the reburning furnace capacity, whereas in the stage (b), only the main burner 14 is turned off. If the flue gas disappears, it means that the combustion gas greatly exceeds the reburning furnace capacity. Accordingly, when the needle of the flue gas concentration meter 36 repeatedly makes a small jump from 0, the pressure in the furnace becomes negative and the output of the main burner 14 is lowered. If the flue gas concentration meter still appears to rise, stop the main combustion burner 14 immediately and make the furnace pressure negative. At this stage, smoke can be prevented almost certainly. However, this smoke concentration control is a so-called follow-up control because control is applied only after smoke is detected.

(6) Oxygen concentration control As shown in FIG. 16, the oxygen concentration at the outlet of the reburning furnace 7 is controlled by the output of the reburning burner 15 and the output of the reburning furnace secondary air. The target value of oxygen concentration is usually 6% and about 3% in the first half of the cremation. When the oxygen concentration does not reach the target value only by the reburning furnace secondary air amount, the reburning burner 15 is stopped and only air is blown from the reburning burner 15. Since there is a clear correlation between the oxygen concentration and the flue gas concentration, it can be operated with empirical rules based on the furnace conditions. Basically, if the oxygen concentration drops below 1%, it will surely smoke. Therefore, by using this empirical rule, the main combustion burner 14 and the main combustion furnace secondary air amount can be operated in the same manner as in the smoke concentration control. In addition, the exhaust gas concentration control is a follow-up control, that is, the control is performed after the exhaust gas is emitted, but it is possible to start the control before the smoke is emitted and to perform more optimal combustion as a rule of thumb. . In general, when the smoke is likely to be emitted, the oxygen concentration change rate is calculated from the phenomenon that the oxygen concentration rapidly decreases, and when this exceeds a certain level, the main burner 14 is controlled to be extinguished. Here, the point at which the value of the change rate changes is an empirical value. By introducing this control, it became possible to stop smoke almost certainly. Therefore, if the oxygen concentration control is performed, the smoke concentration control becomes a secondary control. Therefore, at present, smoke concentration control is positioned as a backup for oxygen concentration control.

(7) Combustion promotion control FIG. 17 shows a combustion promotion control system. In the description of the main combustion furnace 2, the promotion of combustion of the incombustible part of the corpse B in the second half of the cremation was described, but the method of blowing the main combustion furnace secondary air is an important point. That is, the main combustion furnace temperature condition, the blowing timing, and the blowing amount. These are determined based on empirical rules and set in advance in the control computer 30 based on the main combustion furnace temperature measured by the main combustion furnace thermometer 31. Regarding temperature conditions, secondary air was blown only when the temperature was higher than a certain temperature. This is because if the main combustion furnace temperature is low, the combustion promoting effect is small, and the main combustion furnace temperature is lowered, and wasteful fuel is used for temperature rise. Both the blowing timing and the blowing amount (time) are determined based on empirical rules.

<Control result>
The control results of the furnace pressure, temperature (main combustion furnace, recombustion furnace), oxygen concentration, flue gas concentration, and carbon monoxide concentration by the automatic combustion system in actual operation are shown in FIGS. It can be seen that the pressure in the furnace almost falls within the range of −30 Pa to −10 Pa, and the magnitude of the negative pressure decreases as the cremation progresses. Next, the main combustion furnace and recombustion furnace temperatures also maintain the required temperature range. In addition, the oxygen concentration keeps 3% in the first half of the cremation and 6% or more in the second half. The generation of carbon monoxide is extremely small. A small amount of cremation was generated at the beginning of the cremation, because kerosene was used as fuel, and carbon monoxide was generated during ignition. In addition, this furnace does not perform manual operation at all and is automatically operated over the whole. Also, no derecking operation is performed. From the above, this automatic combustion system can be said to be an extremely effective cremation furnace combustion system.

<Summary>
Empirical rules were incorporated into the cremation furnace combustion control system to improve control stability and responsivity. The effects of the present embodiment are summarized as follows.

1) Cremation is self-combustion in the first half due to the presence of a large amount of combustibles in the main combustion furnace. In the second half, the abdomen of the dead body is incinerated with the heat of the main combustion burner. This is a unique combustion process that uses two different combustion methods. In order to efficiently perform this process, a secondary air inlet is provided on the furnace wall of the main combustion furnace, and a frame is provided on the carriage in the furnace.

2) Exhaust gas introduced from the main combustion furnace into the recombustion furnace changes quantitatively. To operate this efficiently, the furnace type of the recombustion furnace is a cylindrical saddle and the inside is throttled. Mixing of exhaust gas was improved by providing two stages. In addition, oxygen concentration control was adopted. Furthermore, the furnace pressure control response was improved.

3) The system was configured so that burner output control, combustion air supply amount control, and furnace pressure control could be performed by a control computer.

4) The combustion control program was created by incorporating empirical rules in addition to the combustion theory. As a result, even in the intermittent operation, stable combustion is performed in the main combustion furnace, and stable combustion is also performed in the recombustion furnace in combination with the improved sensitivity of the furnace pressure control.
As a result, a cremation furnace with stable combustion was completed.

  In the present invention, when exhausting a plurality of cremation furnaces through a common induction blower and exhaust pipe, the pressure fluctuation of a specific cremation furnace is less likely to affect the pressure fluctuation of other cremation furnaces, It can be suitably used as an exhaust control method and system for a cremation furnace that can simplify the control of the cremation furnace.

It is explanatory drawing which shows the current standard cremation process. It is a block diagram which shows the combustion control system of the present general cremation furnace. It is the schematic which shows the condition in the main combustion furnace in the cremation furnace which concerns on this invention. It is the schematic which shows the structure of the recombustion furnace in the cremation furnace which concerns on this invention. It is the schematic which shows the air supply system in the cremation furnace which concerns on this invention. It is a block diagram which shows the furnace pressure control system in the cremation furnace which concerns on this invention. It is a block diagram which shows the control system of the burner in the cremation furnace which concerns on this invention. It is a block diagram which shows the control system in the cremation furnace which concerns on this invention. It is a block diagram which shows the structure of control in the cremation furnace which concerns on this invention. It is the schematic which shows the main combustion furnace temperature control system in the cremation furnace which concerns on this invention. It is the schematic which shows the recombustion furnace temperature control system in the cremation furnace which concerns on this invention. It is a block diagram which shows the furnace pressure control system in embodiment of this invention. It is a block diagram which shows the computer backup system in embodiment of this invention. It is a flowchart of the furnace pressure control method in embodiment of this invention. It is a block diagram which shows the smoke concentration control system in the cremation furnace which concerns on this invention. It is a block diagram which shows the oxygen concentration control system in the cremation furnace which concerns on this invention. It is the schematic which shows the combustion promotion control system in the cremation furnace which concerns on this invention. It is a graph which shows the fluctuation | variation of the furnace pressure in the cremation furnace which concerns on this invention. It is a graph which shows the temperature change in the furnace in the cremation furnace which concerns on this invention. It is a graph which shows oxygen concentration and smoke concentration change in the cremation furnace which concerns on this invention. It is a graph which shows the carbon monoxide density | concentration change in the cremation furnace which concerns on this invention.

Explanation of symbols

1, 1 'Cooling chamber 2, 2' Main combustion furnace 3 In-furnace cart 4 柩 5 Mount 6 Remains 7, 7 'Reburning furnace 8, 8' Cooler 9, 9 'Furnace outlet damper 10 Bag filter 11 Catalyst 12 Attraction Blower 13 Exhaust tube 14 Main combustion burner 15 Reburn burner 16 Secondary air blow-in port 17, 18 Restriction 20 Combustion blower 21a to 21d Control damper 22 Header 23 Inverter 24 Pressure gauge 25, 26 Controller 27 Inverter 28 Controller 29a, 29b Control damper 30 Control computer 31 Main combustion furnace thermometer 32 Furnace pressure gauge 33 Recombustion furnace thermometer 34 Recombustion furnace outlet thermometer 35 Oxygen concentration meter 36 Flue gas concentration meter 37 Main combustion furnace secondary air quantity damper 38 Main Combustion furnace burner output 39 Recombustion furnace secondary air quantity damper 40 Recombustion furnace burner output 41 Furnace outlet damper 42 Fan speed 43 Operation panel touch panel B Body C, C 'Cremation furnace D Common part

Claims (4)

A main combustion furnace provided with a main combustion burner and a main combustion furnace secondary air amount damper for burning the firewood placed on the bogie and the remains, sub-funders, etc.
A reburning furnace installed in communication with the main combustion furnace and provided with a reburning burner and a reburning furnace secondary air amount damper;
A cooler for cooling the exhaust from the reburning furnace;
A furnace outlet damper provided at the outlet of the cooler;
With multiple cremation furnaces,
An induction blower for attracting exhausts from the reburning furnaces of the plurality of cremation furnaces by collecting them in one system;
An exhaust control method for a cremation furnace comprising an exhaust pipe for discharging exhaust gas induced by the induction blower to the atmosphere,
Installing a plurality of control computers for controlling each of the cremation furnaces;
Among the cremation furnaces, by the control computer having jurisdiction over the cremation furnace whose furnace pressure is higher than the set furnace pressure, the furnace pressure of the cremation furnace having the higher furnace pressure is maintained at the set pressure. The induction blower is controlled, and the opening degree of the furnace outlet damper of its own cremation furnace is controlled by another control computer so that the furnace pressure of the cremation furnace under its control becomes a predetermined pressure. Exhaust control method for cremation furnace.   The cremation furnace exhaust control method according to claim 1, wherein the control computers are coupled to each other to enable switching of the operation right of the induction fan.   3. The cremation furnace exhaust according to claim 1, wherein the control computer sets the target value of the furnace pressure in a plurality of stages in accordance with the progress of the cremation process from the ignition of the main combustion burner. Control method. A main combustion furnace provided with a main combustion burner and a main combustion furnace secondary air amount damper for burning the firewood placed on the bogie and the remains, sub-funders, etc.
A reburning furnace installed in communication with the main combustion furnace and provided with a reburning burner and a reburning furnace secondary air amount damper;
A cooler for cooling the exhaust from the reburning furnace;
A furnace outlet damper provided at the outlet of the cooler;
With multiple cremation furnaces,
An induction blower for attracting exhausts from the reburning furnaces of the plurality of cremation furnaces by collecting them in one system;
An exhaust control system for a cremation furnace comprising an exhaust pipe for exhausting exhaust gas induced by the induction fan to the atmosphere,
Installing a plurality of control computers for controlling each of the cremation furnaces;
Among the cremation furnaces, by the control computer having jurisdiction over the cremation furnace whose furnace pressure is higher than the set furnace pressure, the furnace pressure of the cremation furnace having the higher furnace pressure is maintained at the set pressure. In addition to controlling the induction blower, it has means for controlling the opening degree of the furnace outlet damper of its own cremation furnace so that the internal pressure of the cremation furnace under its jurisdiction becomes a predetermined pressure by another control computer Exhaust control system for cremation furnaces.

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