JP3073643B2 - Heat exchanger in incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a heat exchanger in the incineration device.

[0002]

2. Description of the Related Art Conventionally, in the case of incineration of waste, a method has been adopted in which combustion air which is pressure-fed into an incinerator is preheated by using exhaust gas from the incinerator via a heat exchanger. As an example, as shown in FIG. 4, a heat exchanger 41 is connected to a fluidized bed furnace 40 (hereinafter, referred to as an incinerator), and exhaust gas from the incinerator 40 is extracted by an attraction fan 42 into the heat exchanger 4.
1. It is discharged through an exhaust gas treatment facility 43 and a chimney 44. At the same time, air is supplied to the heat exchanger 41 by the blower fan 45 via the valve 46. This air recovers the heat from the exhaust gas in the heat exchanger 41 and is fed to the incinerator 40 as combustion air. And the incinerator 40
In the above, the incinerated material is fluidized together with a fluid medium such as fluidized sand and incinerated with combustion air.

When adjusting the combustion temperature in the incinerator 40, the degree of opening and closing of the valves 46 and 49 is adjusted. That is, the high-temperature air pumped from the heat exchanger 41 to the incinerator 40 and the low-temperature air pumped to the incinerator 40 without passing through the heat exchanger 41 are mixed, and the combustion is performed according to the mixing ratio of the two airs. The temperature of the working air is adjusted.

[0004]

However, in the conventional heat exchanger, if the calorific value of the material to be incinerated in the incinerator 40 increases, the heat exchange in the incinerator 40 must be reduced by heat exchange. Only the air fed directly to the incinerator 40 is supplied without passing through the heat exchanger 41, and the supply of the air fed to the heat exchanger 41 is stopped. Therefore, the vicinity of the outlet 47 of the air discharged from the heat exchanger 41 Temperature rises. For this reason, while the exhaust gas from the incinerator 40 continues to be supplied into the heat exchanger 41, and when the high temperature state of the air outlet 47 continues for a long time, the exhaust gas from the incinerator 40 is removed from the heat exchanger 41. There is a possibility that the temperature in the vicinity of the inlet 48 for introducing the gas into the inside becomes high. In such a case, there is a possibility that the heat exchanger 41 may be thermally damaged by the high heat.

In order to prevent the above thermal damage, if the valve 49 is closed and the valve 46 is opened to supply combustion air to the incinerator 40, the combustion temperature in the incinerator 40 becomes high. Becomes For this reason, the temperature of the fluid medium in the incinerator 40 becomes high, and the fluid media are welded to each other, causing flow obstruction and possibly increasing the concentration of nitrogen oxides (NOx). As a result, the incineration efficiency may be reduced.

The present invention has been made in view of the problems existing in such conventional techniques, and has as its object to reduce the heat damage due to the high heat of the heat exchanger body without lowering the incineration efficiency. and to provide a heat exchanger in the incineration apparatus capable of reliably prevented.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 is provided for accommodating a boundary wall in a casing and burning an incineration object in the casing.
Exhaust gas generated from the incinerator and supplied from the air supply device
Air that has recovered heat through the boundary wall.
Heat exchange in the incinerator that supplies the incinerator as combustion air
In the heat exchanger, the exhaust gas flows against the side wall of the casing.
At least two or more are provided along the road direction to conduct air.
Inlet and a side wall of the casing.
Outlet for exhausting the heat-recovered air
It is provided on the air supply path and conducts air differently from each other.
A valve for selectively introducing from the inlet, and the incinerator
And a valve for supplying auxiliary fuel to the incinerator.
Temperature detection means for detecting a combustion temperature,
Based on the detection signal from the temperature detection means,
Control means for controlling opening and closing of the lube .

[0008]

[0009]

[0010] According to a second aspect of the present invention, a boundary wall is accommodated in a casing, and the exhaust gas generated from an incinerator for burning the incineration material in the casing and the air supplied from the air supply device are mixed. In the heat exchanger of the incinerator, which passes the boundary wall, and supplies the air for which heat recovery has been performed to the incinerator as combustion air, at least two or more of the side walls of the casing extend in the flow direction of the exhaust gas. Provided,
An inlet for introducing air, an outlet provided on the side wall of the casing, and an outlet for discharging the heat-recovered air, and an outlet provided on the supply path of the air. A valve for selectively introducing, a valve for supplying auxiliary fuel to the incinerator, and a temperature detecting means provided near the outlet, for detecting a temperature of air discharged from the outlet. And control means for controlling the opening and closing of the two valves based on a detection signal from the temperature detection means.

[0011]

According to the first aspect of the present invention, the exhaust gas from the incinerator is introduced into the casing, and the exhaust gas is introduced into the casing.
It is discharged through the boundary wall. At the same time, air is
Introduced into the inlet by the supply device, heat exchange with exhaust gas
It is discharged from the exit. Heat recovered air is combustion air
As supplied to the incinerator. And by opening and closing the valve
Each air inlet is selected. The air introduction position can be changed
Of the air discharged from the heat exchanger to the incinerator
The temperature is adjusted. In addition, the temperature detection means
A combustion temperature is detected. Detection signal from the temperature detection means
The opening / closing bar for the control means to introduce air based on the
Valves and valves to supply auxiliary fuel
Control the opening and closing of the heat exchanger and discharge it to the incinerator through the heat exchanger outlet.
The temperature of the discharged air and the temperature of the exhaust gas discharged from the incinerator
The degree is adjusted. Therefore, the temperature in the incinerator is
Always determined without being affected by changes in heat generation and moisture
The incineration efficiency does not decrease due to the temperature.

[0012]

[0013]

[0014] The present invention as described in claim 2, the temperature of the combustion air discharged from the discharge port is detected by the temperature detecting means. Based on the detection signal from the temperature detection unit, the control unit controls the opening and closing of both the opening and closing valve for introducing air and the valve for supplying auxiliary fuel, and the control unit controls the opening and closing of the valve from the outlet of the heat exchanger. The temperature of the air discharged to the incinerator and the temperature of the exhaust gas discharged from the incinerator are adjusted. Therefore, high heat is prevented from being generated near the outlet of the heat exchanger, and heat damage to the heat exchanger can be prevented.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an incinerator for incinerating waste according to an embodiment of the present invention.

As shown in FIG. 2, an incinerator 1 of the incinerator is formed in a cylindrical shape, and a fluidized bed 2 is provided below the incinerator. An air discharge pipe 3 is supported through the side wall of the seat of the incinerator 1 in the fluidized bed 2. Although not shown, a plurality of discharge holes are formed in the lower peripheral wall of the air discharge pipe 3, and combustion air as a heat receiving fluid is discharged from the discharge holes obliquely downward.

An incinerator inlet 4 is provided on an outer wall of the incinerator 1, and the incinerator inlet 4 communicates with the fluidized bed 2. A screw feeder 5 is provided in the incineration object introduction port 4, and the incineration object is introduced into the fluidized bed 2 by rotating the screw feeder 5 by a motor 6. Then, in the fluidized bed 2, the incineration material is formed by the air heated by the auxiliary fuel supplied through the fuel valve 7 and the air supplied from the air discharge pipe 3 together with the fluid medium such as the fluidized sand. It is to be incinerated.

A combustion exhaust gas outlet 8 is provided at the top of the incinerator 1, and exhaust gas as a heat transfer fluid generated by the incineration of the incinerated material is forced from the exhaust gas outlet 8 by an induction fan 9. It is discharged to a chimney 12 via a heat exchanger 10 and an exhaust gas treatment facility 11 adjacent to the incinerator 1.

As shown in FIGS. 1 and 2, an exhaust gas introduction chamber 14 is provided at the top of a casing 13 of the heat exchanger 10 which has a bottomed tapered bottomed cylindrical shape, and a reduced diameter exhaust gas discharge is provided at the bottom. A chamber 15 is provided. An exhaust gas introduction port 16 is provided on the peripheral wall of the exhaust gas introduction chamber 14, and the exhaust gas introduction chamber 1 is provided.
Exhaust gas discharged from the exhaust gas discharge port 8 of the incinerator 1 through the exhaust gas inlet 16 is introduced into the exhaust gas 4.

A plurality of exhaust gas passage pipes 17 are disposed between the exhaust gas introduction chamber 14 and the exhaust gas discharge chamber 15 and serve as boundary walls, and the exhaust gas introduced into the exhaust gas introduction chamber 14 passes through the exhaust gas passage pipe 17. It is transferred to the exhaust gas discharge chamber 15. An exhaust gas outlet 18 is provided on the peripheral wall of the exhaust gas discharge chamber 15,
The exhaust gas introduced into the exhaust gas discharge chamber 15 is transferred to the exhaust gas treatment facility 11 through the exhaust gas outlet 18.
A dust discharge pipe 15 a for discharging ash is opened at the bottom of the exhaust gas discharge chamber 15.
A rotary valve 15b is provided in the opening a.

At the bottom of the exhaust gas introduction chamber 14 and at the top of the exhaust gas discharge chamber 15, a plurality of tie rods 28 extending in the axial direction of the casing 13 (5 in this embodiment).
Book) is fixed through. Plan on the outer circumference of the tie rod 28
A plurality of baffle plates 19 having an oval shape as an inner plate are supported at predetermined intervals, and the baffle plates 19
A cylindrical spacer 29 is externally fitted around the outer periphery of the tie rod 28 except for. Notch 1 of each baffle plate 19
9a is arranged so as to be positioned alternately with respect to 180 ° opposite side of the casing 13 in the peripheral wall opposed to one every other.

A plurality of air inlets 20a to 20f as heat receiving fluid inlets are provided on the outer peripheral wall of the casing 13 between each of the baffle plates 19. An air outlet 21 is provided in the outer peripheral wall of the casing 13 near the exhaust gas introduction chamber 14. Air inlet 20a-2
0f is connected to a blower fan 23 as an air supply device via opening / closing valves 22a to 22f as selecting means.
To 22f. And the air inlets 20a-2
The air introduced from 0f recovers the heat radiated from the peripheral wall of the exhaust gas passage pipe 17, and the heated air passes through the air discharge port 21 to the air discharge pipe 3 of the incinerator 1 as combustion air. Be transported. Note that a silencer 27 is connected to the blower fan 23 via a valve 26.

In the vicinity of the fluidized bed 2, a temperature sensor S1 is provided as first temperature detecting means. The combustion temperature in the fluidized bed 2 is detected by the temperature sensor S1. Further, a temperature sensor S2 as a second temperature detecting means is disposed near the air outlet 21. This temperature sensor S2
Thus, the temperature of the air discharged from the air discharge port 21 is detected.

The temperature sensors S1 and S2, the open / close valves 22a to 22f and the fuel valve 7 are electrically connected to a controller 25 as control means. The controller 25 controls the fuel valve 7 and the open / close valves 22a to 22 based on the temperatures detected by the temperature sensors S1 and S2.
The opening and closing of f is controlled.

Next, the operation and effects of the incinerator configured as described above will be described. In this incinerator, dried waste such as municipal waste is incinerated in a fluidized bed 2 of an incinerator 1 together with a fluidized medium such as fluidized sand. In addition, during the incineration operation, the temperature in the fluidized bed 2 of the incinerator 1 is set to be maintained at 600 ° C to 800 ° C.

The exhaust gas discharged from the incinerator 1 passes through the exhaust gas passage pipe 17 of the heat exchanger 10, so that the peripheral wall of the exhaust gas passage pipe 17 is heated. Then, the exhaust gas that has passed through the exhaust gas passage pipe 17 is discharged from the chimney 12 via the exhaust gas treatment facility 11 and the exhaust gas fan 9.

Air is blown by the blower fan 23 into the casing 13 of the heat exchanger 10 through the air inlets 20a to 20f corresponding to the selectively opened / closed valves among the plurality of open / close valves 22a to 22f. Is done. For example,
When the open / close valve 22f is expanded, air is introduced from the air inlet 20f. In the casing 13, air (indicated by a two-dot chain line in FIG. 2) is pressure-fed to the air outlet 21 so as to meander between the baffle plates 19.
At this time, the air is heated by recovering heat released from the peripheral wall of the exhaust gas passage pipe 17.

For example, the amount of air per unit time introduced from the air inlet 20a when the open / close valve 22a is expanded, and the amount of air per unit time when the open / close valve 22f is expanded. The amount of air introduced per unit time is the same amount of air.

The temperatures of the air introduced from the respective air inlets 20a to 20f are discharged from the air outlet 21 at different temperatures. That is, each air inlet 2
The shorter the flow path distance from 0a to 20f to the air outlet 21 is, the smaller the heat transfer area is, and the shorter the low-temperature heat recovery time is. You. Therefore, the temperature of the air discharged from the air outlet 21 in the order of the air inlets 20a,. The air discharged from the air discharge port 21 is discharged from a discharge hole of the air discharge pipe 3. And the fuel valve 7
The temperature in the fluidized bed 2 is increased by the air heated by the auxiliary fuel supplied through the air and the air from the heat exchanger 10.

On the other hand, the incinerated material is introduced from the incinerated material introduction port 4 and is continuously introduced into the fluidized bed 2 of the incinerator 1 by the screw feeder 5. Accordingly, the incinerated material is incinerated by the high temperature fluidized medium and air.

Since the temperature inside the fluidized bed 2 is detected by the temperature sensor S1, if the temperature falls outside the range of 600 ° C. to 800 ° C., the controller 25 determines the fuel valve based on the detected temperature. 7 and open / close valves 22a to 22f
Control the opening and closing of That is, the temperature of the air heated by the auxiliary fuel and the temperature of the air from the heat exchanger 10 are controlled, and the temperature in the fluidized bed 2 is always maintained at an appropriate value.

Further, the air outlet 2 is detected by the temperature sensor S2.
When the temperature near 1 is detected and the temperature falls outside the set temperature range, the controller 25 controls the opening and closing of the fuel valve 7 and the opening and closing valves 22a to 22f. With this control,
The temperature near the air outlet 21 is always maintained at an appropriate value,
The heat exchanger 10 is not thermally damaged due to abnormally high heat.

Here, a specific example of opening / closing control of the fuel valve 7 and the opening / closing valves 22a to 22f by the controller 25 is shown in Table 1 below. However, the appropriate value of the combustion temperature shown in the table is in the range of 600 ° C to 800 ° C. “22b to 22f” shown in the table indicates the open / close valves 22b to 22f. Further, “○” in the table indicates the expanded state of the fuel valve 7 and the on-off valves 22a to 22f, and “x” indicates the closed state of the fuel valve 7 and the on-off valves 22a to 22f.

[0034]

[Table 1]

Therefore, according to the incinerator configured as described above, when the temperature in the fluidized bed 2 becomes equal to or higher than an appropriate value (800 ° C. in the above case), air is blown to the heat exchanger 10. By changing the air inlets 22a to 22f without stopping the air supply, the air outlet 21
The temperature of the air discharged from can be adjusted. For this reason, even if the temperature in the fluidized bed 2 can be adjusted and the exhaust gas from the incinerator 1 continues to be supplied to the exhaust gas passage pipe 17 of the heat exchanger 10, any of the air introduction ports 20a to 20a 20
Since the air is continuously introduced from f, the vicinity of the air outlet 21 is prevented from becoming high temperature. As a result, the exhaust gas introduction chamber 1
4 can be prevented from being in a high temperature state, so that heat damage to the heat exchanger 10 due to high heat can be prevented.

The controller 25 controls the opening and closing of the fuel valve 7 and the opening / closing valves 22a to 22f in accordance with a change in the temperature detected in the fluidized bed 2 from the temperature sensor S1. Therefore, since the combustion temperature in the fluidized bed 2 is always maintained at an appropriate temperature, the temperature in the fluidized bed 2 does not rise above an appropriate value. As a result, it is possible to prevent the fluid medium from being abnormally high in temperature with the rise of the temperature in the fluidized bed 2 and being welded to cause incineration failure, and to increase the concentration of nitrogen oxides (NOx). Can be suppressed.

Further, the opening and closing valves 22a to 22f are controlled by the controller 25 in accordance with a change in the temperature detected in the fluidized bed 2 from the temperature sensor S1. Therefore, the temperature in the vicinity of the air outlet 21 of the casing 13 can always be maintained at an appropriate value. As a result, it is possible to reliably prevent the heat exchanger 10 from being thermally damaged due to abnormally high heat.

The present invention is not limited to the above-described embodiment, and may be appropriately changed as follows without departing from the spirit of the present invention. (1) In the above embodiment, the multi-tube heat exchanger 10 is used. However, the heat exchanger may be embodied as a convection heat exchanger 30 shown in FIG. The heat exchanger 30 is provided with a cylindrical exhaust gas passage tube 31 along the axial direction of a substantially cylindrical casing 35. A spiral blade 32 as a guide plate is provided between the casing 35 and the exhaust gas passage tube 31, and the spiral blade 32, the casing 35 and the exhaust gas passage tube 3 are provided.
1, the air passage 33 is formed.
A plurality of air inlets 34 a to 34 f communicating with the air passage 33 may be provided on the peripheral wall of the casing 35.

(2) In the above embodiment, the air inlets 20a to 20a
Although six 20f are provided, any number may be provided as long as two or more are provided. (3) In the above embodiment, the controller 25 automatically controls the opening and closing of the fuel valve 7 and the open / close valves 22a to 22f.
The opening degree of the opening / closing valves 22a to 22f may be adjusted and controlled. In this case, the air inlets 20a-2
The amount of air introduced into the fluidized bed 2 can be controlled, and the temperature in the fluidized bed 2 can be further maintained at an appropriate value.

(4) Controller 25 and blower fan 23
And the controller 25 controls the temperature sensor S
Alternatively, the rotation control of the blower fan 23 may be controlled based on the temperature detected by the temperature sensor S2. By doing so, the amount of air introduced into the air introduction ports 20a to 20f can be controlled, and the temperature in the fluidized bed 2 can be further maintained at an appropriate value.

(5) In the above embodiment, the present invention is applied to waste as an incinerated material. However, the present invention may be applied to fluid waste such as human waste or sludge having a high water content. (6) In addition to the multitubular heat exchanger 10 and the convective heat exchanger 30, the heat exchanger may be embodied as a heat-radiating heat exchanger.

(7) The open / close valves 22a to 22f may be manual valves, and may be manually opened / closed based on detection of the temperature sensors S1 and S2 without using a controller.

[0043]

As described in detail above, according to the first aspect of the present invention, the temperature in the incinerator is equal to the temperature detected by the temperature detecting means.
Control means selects the air inlet based on the
For combustion discharged from the casing of the exchanger to the incinerator
The temperature of the air can be adjusted. Also control hand
The stage controls the opening and closing of the fuel valve so that the auxiliary fuel is burned.
Since it can be supplied to the incinerator and heated,
The temperature of the discharged exhaust gas can be adjusted. this
As a result, the temperature inside the incinerator depends on the change in the calorific value and moisture of the incinerator.
Incineration is always maintained at a predetermined temperature without being affected by
It has an excellent effect that the efficiency can be prevented from lowering .

[0044]

[0045]

According to the second aspect of the present invention, the temperature of the combustion air discharged from the discharge port is selected by the control means based on the temperature detected by the temperature detection means.
The temperature of the combustion air discharged from the casing to the incinerator can be adjusted. Further, since the control means controls opening and closing of the fuel valve, the auxiliary fuel can be supplied to the incinerator and heated, so that the temperature of the exhaust gas discharged from the incinerator can be adjusted. As a result, it is possible to prevent a decrease in the incineration efficiency, and it is possible to prevent the heat from becoming high near the discharge port of the heat exchanger, thereby preventing the heat exchanger from being damaged.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a heat exchanger embodying the present invention.

FIG. 2 is an explanatory view showing the entire incinerator.

FIG. 3 is a perspective view of a heat exchanger according to another embodiment.

FIG. 4 is an explanatory diagram of the entire incineration apparatus showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Incinerator, 13 ... Casing, 17 ... Exhaust gas passage pipe (boundary wall), 20a-20f ... Air inlet (heat receiving fluid inlet), 21 ... Air outlet, 22a-22f ... Opening / closing valve (selection means), 25 ... controller (control means), S
1: Temperature sensor (first temperature detecting means), S2: Temperature sensor (second temperature detecting means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F28F 27/00 511 F23G 5/46 F26B 21/00 F28F 27/02

Claims (2)

(57) [Claims] A housing for accommodating a boundary wall in a casing;
Generated from the incinerator for burning incineration material in the shing
Between the exhaust gas and the air supplied from the air supply device
And heat recovered air is used as combustion air.
In the heat exchanger of the incinerator to be supplied to the incinerator, in the direction of the flow path of the exhaust gas with respect to the side wall of the casing.
At least two or more are provided for introducing air.
Inlet and air provided on the side wall of the casing and recovering heat
And a discharge port for discharging air, which is provided on the supply path of the air, and separates the air from each other.
A valve for selectively introducing from an inlet, a valve for supplying auxiliary fuel to the incinerator, and a temperature provided in the incinerator for detecting a combustion temperature.
Based on a detection signal from the temperature detection means and the temperature detection means.
Control means for controlling the opening and closing of the lube.
Heat exchanger in incinerators. 2. A housing for accommodating a boundary wall in a casing,
Generated from the incinerator for burning incineration material in the shing
Between the exhaust gas and the air supplied from the air supply device
And heat recovered air is used as combustion air.
In the heat exchanger of the incinerator to be supplied to the incinerator, in the direction of the flow path of the exhaust gas with respect to the side wall of the casing.
At least two or more are provided for introducing air.
Inlet and air provided on the side wall of the casing and recovering heat
And a discharge port for discharging air, which is provided on the supply path of the air, and separates the air from each other.
A valve for selectively introducing from an inlet, a valve for supplying auxiliary fuel to the incinerator, and air provided near the outlet and discharged from the outlet
A temperature detecting means for detecting the temperature of the battery, and the both buses based on a detection signal from the temperature detecting means.
A heat exchanger in an incinerator, comprising: control means for controlling opening and closing of the lube .