JPH1047631A - Waste incineration treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently raise the temperature of a superheated stream without depending on any external fuel by effectively utilizing the heat of an exhaust gas of a waste incineration treatment apparatus in a type in which a waste heat boiler following a waste incineration treatment furnace is installed in an exhaust gas path for guiding an exhaust gas of the waste incineration treatment furnace to a stack. SOLUTION: An exhaust gas takeoff path 10 is provided to take out a part of an exhaust gas from near an installation part of a waste boiler 3 in an exhaust gas path 2 intact as high temperature exhaust gas. The exhaust gas takeoff path 10 is provided with a high temperature filter 11 comprising an inorganic porous body to remove soots in the high temperature exhaust gas. A superheater 12 is provided on the downstream side of the high temperature filter 11 to superheat the steam from the waste heat boiler 3 by the high temperature exhaust gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste incineration apparatus and, more particularly, to a waste heat boiler following the waste incineration furnace in an exhaust gas path for guiding exhaust gas from the waste incineration furnace to a chimney. Related to a waste treatment apparatus.

[0002]

2. Description of the Related Art Conventionally, in waste incineration equipment,
As shown in FIG. 4, a waste heat boiler 3 disposed at a furnace outlet of the waste incineration furnace 1 is provided in a flue 2 that forms an exhaust gas path that guides exhaust gas from the waste incineration furnace 1 to a chimney 6. An economizer 4 for collecting heat of exhaust gas in the water supply to the waste heat boiler 3, a bag filter 5 for collecting dust in the exhaust gas,
An exhaust gas treatment device 8 including a flue gas denitration device, a smoke washing device, and the like for purifying exhaust gas after dust removal, and an exhaust gas for preventing white smoke from being generated in exhaust gas discharged from the chimney 6 into the atmosphere; A white smoke prevention device 7A provided with a heating means is sequentially provided. Further, in a steam path for supplying steam from the waste heat boiler 3 to a steam turbine T for generating electricity by driving a generator G, external combustion in which the steam is overheated using city gas or the like as fuel in order to increase the power generation efficiency. A superheater 9 is provided.

[0003]

In the above-mentioned conventional waste incineration apparatus, when power generation equipment is provided and power is to be generated, the steam from the waste heat boiler 3 is superheated by the external combustion superheater 9, There is a problem that fuel such as city gas is required. The reason why the external combustion superheater 9 is provided is that the exhaust gas of the waste incineration furnace 1 contains hydrochloric acid and the like, and also dust such as fly ash accompanies the dust. If it adheres to the evaporating tube or steam tube of a superheater, iron salts such as iron chloride are formed and corrode there (high-temperature corrosion). Since the region is at least 320 ° C., in order to avoid the high-temperature corrosion, it is necessary to suppress the wall temperature of the evaporating pipe and the steam pipe to 320 ° C. or less. Because it is difficult to raise Under these conditions, the power generation efficiency is less than 20%. In order to solve the above problem, a combined power generation facility as shown in FIG. 5 has been developed as a facility for improving thermal efficiency by positively combining gas turbine power generation and power generation using waste heat in a waste incineration furnace. In this combined cycle power generation facility, the arrangement of various facilities in the exhaust gas path is the same as that of the above-mentioned conventional waste incineration treatment apparatus, but a gas turbine power generation facility is separately provided, and the heat source of the external combustion superheater 9 is a gas turbine. The steam condition at the outlet of the superheater was set to about 4 MPa and 400 ° C., and the power generation efficiency of 24% was achieved. Moreover, there is no risk of corrosion of the superheated steam pipe. However, there is a problem that equipment such as a gas turbine and an external fuel are required. In addition, since the above-mentioned combined power generation facility has the above-described configuration, it is not suitable for coupling small-sized waste incineration equipment, and does not exhibit a sufficient effect. In addition, there remains a problem in the effective use of the heat retained in the exhaust gas from the waste incinerator. Accordingly, the waste incineration treatment apparatus of the present invention solves the above-described problems, and sufficiently increases the superheated steam temperature without relying on external fuel while effectively utilizing the heat of the exhaust gas from the waste incineration treatment furnace. Is possible,
For example, when steam is supplied to a power generation facility, an object is to provide a means capable of improving the power generation efficiency.

[0004]

[Means for Solving the Problems]

[First characteristic configuration] The first characteristic configuration of the waste incineration treatment apparatus of the present invention for the above purpose is as described in claim 1.
In addition to providing an exhaust gas extraction path for taking out a part of the exhaust gas as a high temperature exhaust gas from the vicinity of the installation site of the waste heat boiler in the exhaust gas path from the waste incineration furnace, the inorganic material for removing the dust in the high temperature exhaust gas in the exhaust gas extraction path A high-temperature filter made of a porous body is provided, and a superheater for heating steam from the waste heat boiler with the high-temperature exhaust gas is provided downstream of the high-temperature filter. [Effects of the first feature configuration] According to the first feature configuration, the risk of corrosion (so-called high-temperature corrosion) due to the formation of iron salts such as iron chloride can be reduced, so that the steam superheat temperature in the superheater can be reduced. It is possible to maintain sufficiently high. More specifically, in the high-temperature corrosion, dust adheres to the surface of a heat transfer tube such as a steam pipe, that the attached dust retains moisture, and that chlorine content (normally, The presence of corrosive components such as hydrochloric acid) and the temperature of the atmosphere at a temperature of 320 ° C. or higher are three major factors. By arranging the high-temperature filter upstream of the superheater, it is possible to prevent dust from adhering to the surface of the heat transfer tube, and therefore, it is possible to remove dust, which is one of the factors, so that corrosion can be largely suppressed. . Further, if slaked lime or the like is blown in from the upstream side of the high temperature filter, hydrochloric acid and the like, which are corrosive components, can be neutralized, so that the suppression of corrosion becomes more effective. In addition, since the high-temperature exhaust gas is guided from the exhaust gas extraction passage, the exhaust gas introduced into the superheater is high in temperature, and the steam superheat temperature can be maintained sufficiently high, so that fuel for steam superheat is not required. Moreover, since the high-temperature filter is formed of an inorganic porous material, it does not have flexibility like a heat-resistant bug, does not change with the gas pressure of the openings, and is stable even if the ventilation pressure loss is increased. It is possible to reduce the size of the high-temperature filter because dust can be removed by the dust filter. The inorganic porous body forming the high temperature filter may be a porous ceramic sintered body or a porous metal sintered body.
In this case, if the heat transfer surface temperature of the superheater is 600
Even if the temperature exceeds ℃, there is no risk of rapid corrosion, and the steam condition at the outlet of the superheater can be set to 9 MPa and 500 ° C. The inorganic porous material is fired under isostatic pressure (so-called HIP) in view of the minimum blocking particle size, air permeability, strength and the like.
Molded). In other words, by adjusting the particle size and subjecting the particles having a small range of particle size to HIP molding, a sintered body having a substantially uniform pore diameter can be obtained, and the distribution of the pores can be made uniform. Is higher than the sintering temperature, and as a result, the ventilation flow rate can be increased. Incidentally, since the filtration speed of the bag filter is generally suppressed to about 1 m / min, a large filtration area is required. Furthermore, the heat resistance temperature of a general bag filter is low, about 250 ° C. as a result,
While effectively utilizing the heat of exhaust gas from waste incinerators,
The superheated steam temperature can be increased sufficiently without relying on an external fuel. Therefore, when steam is supplied to the power generation equipment, the power generation efficiency can be improved.

[Second feature configuration] A second feature configuration of the waste incineration treatment apparatus of the present invention for the above purpose is as described in claim 2, wherein the superheater in the exhaust gas extraction path in the first feature configuration is provided. A damper mechanism for adjusting the flow rate of the high-temperature exhaust gas is provided on the downstream side. [Function and effect of second characteristic configuration] According to the second characteristic configuration, the steam condition at the superheater outlet can be controlled without being affected by the operating conditions of the waste incineration furnace. That is, by adjusting the flow rate of the high-temperature exhaust gas by operating the damper mechanism, the heat transfer conditions in the superheater can be easily controlled. Therefore, even when the temperature of the outlet of the waste heat boiler fluctuates in accordance with the combustion state of the waste in the waste incineration furnace, the temperature of the high-temperature exhaust gas from the exhaust gas extraction path does not fluctuate extremely, Since high-temperature exhaust gas is guided to the superheater, superheated steam conditions in the superheater can be easily controlled.For example, when power is supplied by supplying steam to a steam turbine, the amount of power generation is adjusted according to power demand. It can be changed. As a result, in addition to the effect of the first characteristic configuration, the steam condition at the outlet of the superheater can be controlled.

[Third characteristic configuration] A third characteristic configuration of the waste incineration apparatus of the present invention for the above purpose is as defined in the first characteristic configuration or the second characteristic configuration. The point is that the downstream end of the exhaust gas extraction passage is connected to the exhaust gas passage before the chimney. [Function and effect of third feature configuration] According to the third feature configuration, it is possible to prevent white smoke from being generated in exhaust gas discharged from the chimney into the atmosphere. In other words, if the exhaust gas cooled due to the restriction of the inlet gas temperature of the bag filter provided in the exhaust gas path is directly discharged into the atmosphere from the chimney, the moisture contained in the exhaust gas condenses in supersaturation to generate white smoke. However, by mixing the high-temperature exhaust gas from the exhaust gas extraction passage, it is possible to reduce the saturation of the water by increasing the temperature of the exhaust gas reaching the chimney, and even if it is released into the atmosphere as it is, To prevent condensation and condensation. As a result, emission of white smoke from the chimney can be prevented. Therefore, it is possible to omit the equipment of the generally installed white smoke prevention device, to reduce the amount of equipment,
And energy can be used effectively.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the waste incineration apparatus of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the waste incineration apparatus of the present invention.

The waste incinerator 1 has a waste heat boiler 3 in an exhaust gas passage 2 for guiding exhaust gas to a chimney 6 by an induction blower mechanism B.
In the exhaust gas passage 2, a cooling tower provided with an economizer 4, a bag filter 5, an exhaust gas treatment device 8, and an exhaust gas mixer 7 as a white smoke prevention device 7A are sequentially arranged on the downstream side. is there. The exhaust gas treatment device 8 includes a flue gas denitration device for purifying exhaust gas after dust removal. Further, an exhaust gas extraction passage 10 for extracting a part of the high-temperature exhaust gas from the downstream side of the evaporating pipe of the waste heat boiler 3 is provided and connected to the exhaust gas mixer 7. A high temperature filter 11, a superheater 12 for superheating steam from the waste heat boiler 3, and a damper mechanism 13 for adjusting a flow rate of the high temperature exhaust gas are sequentially provided in the exhaust gas extraction path 10, and the high temperature filter 11 On the upstream side, a lime supply device 14 for blowing and supplying slaked lime powder is arranged. After the steam from the waste heat boiler 3 is superheated by the superheater 12, the steam is sent to a steam turbine T that drives a generator G, exits the steam turbine T, is condensed, and is supplied to the waste heat boiler 3 Is returned to.

As shown in FIG. 2, the high-temperature filter 11 has a gas inlet 11 below the high-temperature filter 11.
a, a partition wall 11c for vertically dividing the inside of the high-temperature filter 11, and a gas outlet 11 above the partition wall 11c.
b, and a filter main body 20 attached to the partition wall portion 11c, and a reverse pressure in a direction opposite to a flow direction of the high-temperature exhaust gas flow of the filter main body 20 disposed above the partition wall portion 11c. A back-pressure cleaning device 21 for injecting high-pressure air for cleaning, a rotary valve 22 for removing dust blown down by the back-pressure cleaning from the high-temperature filter 11, and a screw conveyor 23 for discharging the removed dust. And

The filter body 20 includes the partition 1.
1c, a porous sintered metal cylinder 20a as an inorganic porous body having an open upper end and a closed lower end.
And a venturi 20b disposed at the upper end of the porous metal sintered cylinder 20a.

The high-temperature filter 11 is supplied with high-temperature exhaust gas from an exhaust gas extracting passage 10 from the gas inlet 11a, passes through the porous metal sintered cylinder 20a, and extracts the exhaust gas from the gas outlet 11b. It is discharged to the downstream side of the road 10. When the high-temperature exhaust gas passes through the porous metal sintered cylindrical body 20a, dust in the high-temperature exhaust gas is captured.

Exhaust gas discharged into the atmosphere from the chimney 6 through the exhaust gas path 2 is heated by the economizer 4 to supply water to the waste heat boiler 3 while being cooled by the temperature reducing tower. The dust is removed by the bag filter 5, detoxified by the exhaust gas treatment device 8, mixed with the high-temperature exhaust gas from the exhaust gas take-out passage 10 to the exhaust gas mixer 7, and sent to the chimney 6 by the induction blowing mechanism B, Released into the atmosphere. On the other hand, the high-temperature exhaust gas extracted from the exhaust gas extraction passage 10 is blown with slaked lime powder from the lime supply device 14,
It is sent to the high temperature filter 11. At this time, the temperature of the high-temperature exhaust gas is reduced to about 550 to 580 ° C. This is because the melting temperature of fly ash in the high-temperature exhaust gas is about 600 ° C. Therefore, in order to prevent fly ash in a partially molten state from adhering to the porous metal sintered cylinder 20a, it is necessary to use a temperature higher than 600 ° C. This is because it is necessary to cool to a low temperature and introduce it to the high temperature filter 11. The blown slaked lime powder comes into contact with the high-temperature exhaust gas, neutralizes acids such as hydrochloric acid in the high-temperature exhaust gas, and is trapped on the outer surface of the porous metal sintered cylinder 20a, and does not contain dust from which the acid component has been removed. The high-temperature exhaust gas is sent to the superheater 12 and superheats the steam from the waste heat boiler 3. The acid component that has reached the porous metal sintered cylinder 20a without reacting with the slaked lime powder blown from the lime supply device 14 is also captured on the surface of the porous metal sintered cylinder 20a. Since it reacts upon contact with the powder, the efficiency of the slaked lime powder blown from the lime supply device 14 can be increased. Further, since both the dust and the acid component have been removed, two of the above-mentioned three factors of the high-temperature corrosion can be removed. Regardless of the temperature of the high-temperature exhaust gas, the corrosion of the steam pipe of the superheater 12 can be prevented. Can be sufficiently prevented. The temperature of the superheated steam from the superheater 12 can be controlled by adjusting the opening of a damper mechanism 13 provided in the exhaust gas take-out passage 10.

The high-temperature exhaust gas from the superheater 12 is mixed with the low-temperature exhaust gas from the exhaust gas treatment device 8 in the exhaust gas mixer 7, and the temperature of the exhaust gas discharged from the chimney 6 is increased. Prevents white smoke from being released. Therefore, according to the above configuration, there is no need to provide a conventionally provided white smoke prevention device.

The high temperature filter 11 is regenerated intermittently at predetermined intervals. That is, the operation valve 21 of the back pressure cleaning device 21 is periodically controlled by the back pressure cleaning control means C.
b is opened for a predetermined time.
High-pressure air is blown out from c to remove dust and slaked lime powder after the reaction attached to the surface of the porous metal sintered cylinder 20a. Here, the jet pressure of the high-pressure air from the backwash nozzle 21c is prevented from back-propagating by the venturi 20b, and the jet pressure effectively removes dust and the like adhering to the porous metal sintered cylindrical body 20a. Works. The jet pressure, jet flow rate, jet interval, etc. of the jet gas for the back pressure cleaning should be set as appropriate. The lime powder blown down as a result of the back pressure washing is discharged downward by a rotary valve 22 provided below the high temperature filter 11 and sent out by a screw conveyor 23.

Next, another embodiment of the present invention will be described. <1> In the above embodiment, the exhaust gas take-out path 10
Is connected to the downstream side of the evaporator tube of the waste heat boiler 3, but may be connected to the side of the waste heat boiler 3 as shown in FIG. The connection position of the exhaust gas extraction passage 10 may be determined according to the service temperature of the high-temperature filter 11, and may be connected upstream of the waste heat boiler 3. <2> In the above embodiment, the high-temperature filter 11
An example is shown in which the lime supply device 14 for blowing slaked lime powder into the high-temperature exhaust gas is disposed upstream of the lime supply device. However, the lime supply device may be omitted depending on conditions. Even if the lime supply device 14 is omitted, dust, which is one of the factors of corrosion, has been removed as described above, so that corrosion of the heat transfer tube of the superheater 12 can be prevented. <3> In the above embodiment, the exhaust gas take-out path 10
Is connected to the exhaust gas mixer 7, but may be connected directly to the chimney 6. Since it is mixed with the exhaust gas from the exhaust gas path 2 in the chimney 6 and raises the exhaust gas temperature,
It has the effect of preventing white smoke. <4> In the above embodiment, the exhaust gas take-out path 10
Although the example in which the damper mechanism 13 is provided is shown, the damper mechanism 13 may be omitted when it is not necessary to control the flow rate of the high-temperature exhaust gas. <5> In the above embodiment, an example in which the porous metal sintered cylindrical body 20a is arranged as an inorganic porous body has been described, but it is more preferable that the sintered body is sintered under isostatic pressure. The characteristics as a ventilation body become more preferable. The inorganic porous body may be a ceramic sintered body, a refractory porous body, or a cermet (a mixed sintered body of a metal and a nonmetal). Further, a filter made of a heat-resistant inorganic fiber material (for example, silica-alumina fiber), a filter formed of the inorganic fiber using a heat-resistant binder, and the like can be used. <6> In the above embodiment, an example was described in which high-pressure air was used as the gas ejected from the backwash nozzle 21c. However, the ejected gas may be high-pressure steam, and depending on the type of collected dust. This is preferred.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a waste incineration apparatus according to the present invention.

FIG. 2 is an explanatory view showing an example of a high temperature filter according to the present invention.

FIG. 3 is an explanatory view showing another arrangement of the exhaust gas extraction path according to the present invention.

FIG. 4 is an explanatory view of an example of a conventional waste incineration apparatus.

FIG. 5 is an explanatory diagram showing another example of a conventional waste incineration apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waste incineration furnace 2 Exhaust gas path 3 Waste heat boiler 6 Chimney 10 Exhaust gas extraction path 11 High temperature filter 12 Superheater 13 Lime supply device

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shigeru Tanaka 1-1-1 Hama, Amagasaki-shi, Hyogo Pref.

Claims (3)

[Claims] 1. A waste heat boiler (3) subsequent to the waste incineration furnace (1) is installed in an exhaust gas path (2) for guiding exhaust gas from the waste incineration furnace (1) to a chimney (6). An exhaust gas take-out path (10) for taking out a part of the exhaust gas as a high-temperature exhaust gas from a vicinity of an installation site of the waste heat boiler (3) in the exhaust gas path (2); A high-temperature filter (11) made of an inorganic porous material for removing dust in the high-temperature exhaust gas is provided in the exhaust gas extraction path (10), and a high-temperature filter (11) is provided downstream of the high-temperature filter (11) from the waste heat boiler (3). A waste incineration apparatus provided with a superheater (12) for superheating the steam of the above by the high-temperature exhaust gas. 2. The waste incineration treatment according to claim 1, further comprising a damper mechanism (13) for adjusting a flow rate of the high-temperature exhaust gas, provided downstream of the superheater (12) in the exhaust gas extraction passage (10). apparatus. 3. The waste incineration according to claim 1, wherein a downstream end of the exhaust gas discharge passage (10) is connected to the exhaust gas passage (2) in front of the chimney (6). Processing equipment.