JP2001324129A - Gas-cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-cooling apparatus in which a flue is prevented from clogging, and degradation in cooling performance is prevented. SOLUTION: A membrane part 8 (9) is constituted multiply by jointing circularly pipe channels 8a, 8a (9a, 9a) with intervals between them to constitute a flue 12 for passing a flue gas between the membrane parts 8 and 9. The interval between the membrane parts is set optimally to pass the exhaust gas through the flue 12 at a predetermined rapid flow-velocity without making a narrow part all through the flue 12. Opposing surfaces of the membrane parts 8 and 9 forming the flue 12 are made heat-transfer surfaces, and a predetermined heat-transfer area is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas cooling device for cooling exhaust gas flowing through a flue by bringing the exhaust gas into contact with a pipe through which a cooling medium flows.

[0002]

2. Description of the Related Art FIG. 7 is a cross sectional view showing a convective gas cooling apparatus according to the prior art. This convection type gas cooling device includes a plurality of water pipes 10 through which cooling water flows, and a flue 20 of exhaust gas formed between the water pipes 10 by disposing the plurality of water pipes 10. Flue 2
When the exhaust gas flows through the water pipe 0, the exhaust gas contacts the outer surface (flue constituting surface) of the water pipe 10 and is cooled.

[0003]

Here, dust is contained in the exhaust gas. For this reason, if the water pipes 10 are densely arranged in order to enhance the cooling performance (to increase the heat transfer area), a narrow portion is partially formed in the flue 20, and the dust adhering to the outer surface of the water pipe 10 causes the smoke Road 20 gets clogged. On the other hand, when the water pipes 10 are arranged at a certain interval, the flow velocity of the exhaust gas flowing through the flue 20 becomes 2 m / s to 3 m.
/ S, the dust tends to adhere to the outer surface of the water pipe 10, and the number of water pipes is reduced, so that the heat transfer area is reduced, and as a result, the cooling performance is reduced.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a gas cooling device that prevents clogging of a flue and deterioration of cooling performance.

[0005]

A gas cooling apparatus according to the present invention is a gas cooling apparatus for cooling exhaust gas flowing through a flue by bringing the exhaust gas into contact with a pipe through which a cooling medium flows. The invention is characterized in that a membrane section is formed to connect the pipes in a ring-like manner, and the membrane section is multiplexed, and a flue through which exhaust gas flows is provided between the membrane sections.

[0006] According to the gas cooling apparatus constructed as described above, the membrane sections formed by connecting the pipes through which the cooling medium flows in a ring-like manner are multiplexed, and the flue gas flows between the membrane sections. Therefore, by optimally setting the interval between the membrane portions, it is possible to increase the flow velocity of the exhaust gas flowing through the flue to a predetermined speed without forming a narrow portion in the entire flue and The opposing surfaces of the membrane portions on both sides forming the flue are heat transfer surfaces, and a predetermined heat transfer area is secured.

Here, as a specific configuration in which the narrow portion is not formed in the entire flue, for example, the membrane portions on both sides forming the flue are alternately arranged such that the conduits are alternately arranged along the circumferential direction. A staggered arrangement is used.

Further, when the number of the multiple membrane portions is, for example, three or more, the amount of heat transfer (degree of cooling) differs between the respective membrane portions, so that it is particularly preferable to make the number of the double membrane portions.

Further, the flow velocity of the exhaust gas in the flue is 5 m / s
It is preferably set to 15 m / s. This is because if the flow rate of the exhaust gas in the flue is lower than 5 m / s, the dust tends to adhere to the outer surface of the pipeline, and if it is higher than 15 m / s, a problem of pressure loss occurs.

In addition, if a hammering device is provided to enable the hammering of the membrane portion, even if the flue is clogged, the hammering of the hammering device may cause the clogging of the flue without stopping the operation. Removed.

In addition, if the hammering device is configured to be able to hammer multiple membrane portions at the same time, it is not necessary to provide hammering devices in accordance with the number of membrane portions.

Further, as the exhaust gas, specifically, for example, a combustible gas discharged from a gasification furnace for pyrolyzing and gasifying a combustible material can be mentioned. Since the combustible gas contains dust, the function of the gas cooling device is sufficiently exhibited.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing a municipal solid waste pyrolysis gasification system to which a gas cooling device according to the present invention is applied.

This municipal waste pyrolysis gasification system converts municipal waste into pyrolysis gas and converts the high-temperature flammable gas (exhaust gas) generated by the pyrolysis gasification into a clean flammable gas from which ash and harmful substances have been removed. It is a system that collects and uses it effectively.

In this system, the input municipal waste A
, A gas cooling device 3 for sequentially cooling a combustible gas discharged from the gasification furnace 1 to a predetermined temperature, and a combustible gas discharged from the gas cooling device 3. Filter (dust collector) 4 installed in the flammable gas discharge path Y to collect harmful substances and dust in combustible gas
And

The gasifier 1 converts the input municipal waste A into
Pyrolysis gasification is performed at about 900 ° C., and solid matter B such as furnace ash generated by the pyrolysis gasification is appropriately discharged from the bottom, and a combustible gas generated in the gasification furnace 1 is attached. To cyclone 2. Cyclone 2 is a solid-
The gas (solid-gas) separation device returns the separated solid matter into the gasification furnace 1 and supplies the separated combustible gas to the gas cooling device 3 via the gas supply path X1. The separated combustible gas contains high-molecular hydrocarbon called tar and dust containing unburned carbon and salts.

The gas cooling device 3 includes a radiation type gas cooling device 3.
a, a convective gas cooling device 3b and a economizer 3c, which are arranged in this order with respect to the flow of combustible gas. Radiant gas cooling device 3a and convective gas cooling device 3b
Is communicated by the gas supply path X2, and the flammable gas cooled by the radiation type gas cooling device 3a is
2 and is sent to the convection type gas cooling device 3b. The convective gas cooling device 3b and the economizer 3c are connected by a gas supply path X3, and the combustible gas cooled by the convective gas cooler 3b passes through the gas supply path X3. 3c.

Each of the radiant gas cooling device 3a, the convective gas cooling device 3b and the economizer 3c is formed between a water pipe (cooling medium pipe) through which cooling water (cooling medium) flows and the water pipe. And a flue of combustible gas to be discharged. When the combustible gas passes through the flue, the combustible gas comes into contact with the outer surface of the water pipe (flue component surface) and cools the combustible gas. .

The radiant gas cooling device 3a is, for example, constituted by arranging water tubes side by side on the outer periphery of a furnace, and cools a flammable gas of about 900 ° C. to about 450 ° C. mainly by radiation. The convection-type gas cooling device 3b has a configuration described later in detail, and supplies a combustible gas at about 450 ° C. to a heat transfer function for about 25 ° C.
Cool to 0 ° C. The economizer 3c has a known configuration for saving fuel, and further cools the combustible gas at about 250 ° C. to a predetermined temperature.

In this system, the gas cooling device 3
And a slaked lime supply device 5 for supplying slaked lime to a position upstream of the bag filter 4 in the discharge path Y. This slaked lime has not only a function as a dechlorinating agent that binds to chlorine as a harmful substance, but also a function as a sulfur removing agent that binds to sulfur as a harmful substance. The slaked lime supply device 5 is provided for the combustible gas flowing through the discharge path Y.
Slaked lime is supplied (mixed) using a supply medium gas such as nitrogen
I do.

The bag filter 4 appropriately discharges a solid substance C composed of harmful substances and dust in the combustible gas combined with the slaked lime from the bottom, and a clean combustible gas D from which the solid substance C has been removed. To be discharged.

Next, a convection type gas cooling device 3b which is a feature of the present embodiment will be described. FIG. 2 is a longitudinal sectional view showing the convection type gas cooling device 3b, FIG. 3 is a plan view showing the convection type gas cooling device 3b, FIG. 4 is a diagram shown by arrows PP in FIG. 2, and FIG. FIG. 6 is an enlarged view showing the hammering seat of the hammering device in FIG. 4 extracted therefrom. FIG. 6 is a view taken along the line QQ in FIG.

The convective gas cooling device 3b has a substantially hollow cylindrical shape as shown in FIGS. 2 to 4, and has a flammable gas flowing through the gas supply path X2 on its lower side surface as shown in FIG. A gas inlet 6 for introducing gas into the inside,
A gas outlet 7 for discharging the flammable gas cooled inside to the gas supply path X3 is provided on the upper side surface.

As shown in FIGS. 2 and 4, a water pipe 8a extending vertically and through which cooling water flows is provided on the outer periphery of the body between the gas inlet 6 and the gas outlet 7, as shown in FIGS. Thus, a large number are arranged side by side in the circumferential direction. These water tubes 8a, 8a are annularly separated from each other and connected to each other by a connecting plate 8b, and a so-called membrane portion 8 is formed on the outer periphery of the body.

Similarly, a number of water pipes 9a, 9 which are arranged in the circumferential direction and are annularly spaced inside the membrane portion 8 are similarly provided.
a are connected to each other by a connecting plate 9b. The water tubes 8a, 9a and the connecting plates 8b, 9b constituting these membrane parts 8, 9 are formed of the same material.

Water tubes 8a, 8a constituting the membrane section 8
As shown in FIG. 2, the lower portions thereof have annular water pipes 8.
c, the cooling water flowing into the water pipe 8c from the cooling water inlet 8e is allowed to flow into each of the water pipes 8a, 8a, and the upper part thereof is connected by an annular water pipe 8d, and each of the water pipes 8a , 8a can flow out of the cooling water outlet 8f through the water pipe 8d. Similarly, the lower portions of the water pipes 9a, 9a constituting the membrane section 9 are connected by an annular water pipe 9c, and the cooling water flowing into the water pipe 9c from the cooling water inlet 9e flows into each of the water pipes 9a, 9a. While being made possible, the upper part is connected by the annular water pipe 9d, and the cooling water of each water pipe 9a, 9a can flow out from the cooling water outlet 9f via the water pipe 9d.

The space inside the inner membrane section 9 is closed at the top, and serves as a gas filling section 11 for filling a combustible gas flowing from the gas inlet 6. The gas filling unit 11 also has a function as a radiating unit that cools the combustible gas filled in the gas filling unit 11 by the radiation action of the membrane unit 9.

2 and 4 are provided between the membrane portions 8 and 9.
As shown in FIG. 2, a flue 12 is formed in which the combustible gas flowing from the gas inlet 6 flows upward from below. Opposing surfaces of the water pipes and the connecting plates of the membrane portions 8 and 9 forming the flue 12 are heat transfer surfaces, and the flue 12 is a gas cooling portion. Then, the combustible gas flowing through the gas cooling section is discharged from the gas outlet 7 as shown in FIG.

The distance between these membrane parts 8, 9 is
The flue 12 is formed without forming a narrow portion in the entire flue 12.
The optimal interval is set so that the flow rate of the flammable gas flowing through the air can be increased to a predetermined speed. In particular, the water pipes 8a, 9a are arranged in a staggered arrangement alternately arranged along the circumferential direction as shown in FIG. 4 so as not to form a narrow portion in the entire flue 12.

Here, it is preferable to set the interval between the membrane portions 8 and 9 so that the flow rate of the combustible gas flowing through the flue 12 is 5 m / s to 15 m / s. This is because when the flow rate of the flammable gas in the flue 12 is lower than 5 m / s, dust in the flammable gas is removed from the water pipes 8a, 9a and the connecting plates 8b, 9
This is because it tends to adhere to the outer surface of b, and if it is faster than 15 m / s, a problem with pressure loss occurs. Therefore, in the present embodiment, the flow rate of the combustible gas in the flue 12 is 10 m / s.
The interval between the membrane portions 8 and 9 is set so that

Further, as shown in FIGS. 2, 4 to 6, the convection type gas cooling device 3b has a hammering device 1 for removing the clogging of the flue 12 even if it is clogged.
3 are installed at three equally spaced positions in the circumferential direction (see FIG. 4).

As shown in FIGS. 4 to 6, the hammering device 13 has a box-shaped hammering seat 13a connected to the outer membrane part 8, and is supported by the hammering seat 13a and has a hammering capability. Seat 1
And a hammer 13b capable of hammering 3a.

The hammering seat 13a is on the outside (hammering portion 13b side)
And a plurality of side plates 13d connecting the hammering plate 13c and the connecting plate 8b of the outer membrane portion 8 to each other, and a hammering plate 13c whose substantially center is hammered by the hammering portion 13b.
A plurality of partition plates 13e are arranged in the vertical direction, connected to the hammering plate 13c and the side plate 13d, and connected to the water pipe 8a and the connection plate 8b of the outer membrane part 8, and the partition plate 13e and the inner side. A plurality of hammering connecting plates 13f for connecting the water pipes 9a of the membrane section 9 to each other.

The hammer 13b includes an actuator 13g such as an air cylinder. In the hammering device 13 including the hammering portion 13b and the hammering seat 13a, the movable portion of the actuator 13g of the hammering portion 13b protrudes, and thereby the hammering plate 13c of the hammering seat 13a.
The vibration caused by the hammering is transmitted to the outer membrane portion 8 via the hammering plate 13c, the side plate 13d, and the partitioning plate 13e, and is also transmitted through the partitioning plate 13e and the hammering connecting plate 13f. Is transmitted to the membrane section 9 of the first section.

According to the system configured as described above,
The input municipal solid waste A is pyrolyzed and gasified by the gasifier 1 to generate a flammable gas at about 900 ° C. Chlorine contained in municipal waste gasifies when the municipal waste is heated to about 200 ° C. or higher. Therefore, this combustible gas contains chlorine and sulfur.

The combustible gas generated in the gasification furnace 1 passes through the cyclone 2 and the gas supply path X1, and is first introduced into the radiant gas cooling device 3a to be cooled, and then the gas supply path X2 Through the gas inlet 6 and into the convective gas cooling device 3b.

A part of the combustible gas introduced into the convective gas cooling device 3b is filled in the filling portion 11 and cooled by radiation, and the other is a flue gas 12 formed between the membrane portions 8 and 9. And is cooled by contacting the water pipes and connecting plates of the membrane portions 8 and 9.

At this time, the interval between the membrane parts 8 and 9 is
The flue 1 is formed without forming a narrow portion in the entire flue 12.
Since the flow rate of the flammable gas flowing through the flammable gas 2 is set at an optimum interval of 10 m / s to be a predetermined high speed, dust in the flammable gas hardly adheres to the water pipe and the connecting plate, and the flue 12 is not clogged. Then, the combustible gas passes through the flue 12 while being cooled well. At this time, the flammable gas is provided with a heat transfer surface between the opposing surfaces of the membrane portions 8 and 9 so that a predetermined heat transfer area is secured, and dust adheres to the water pipe and the connection plate as described above. Since it is difficult, it is cooled to a predetermined temperature.

The cooled combustible gas is supplied to the economizer 3 through the gas outlet 7 and the gas supply path X3.
c, is cooled and discharged to the discharge path Y.

At this time, in the radiation type gas cooling device 3a, the convection type gas cooling device 3b, and the economizer 3c, sensible heat is obtained when cooling the combustible gas. This sensible heat is supplied to, for example, a refuse drying device for drying municipal waste, a power generation system, and a cooling and heating system employed in the municipal waste pyrolysis gasification system, and is effectively used.

Slaked lime is mixed into the combustible gas discharged from the economizer 3c to the discharge path Y by the slaked lime supply device 5. Here, the combination of slaked lime with chlorine and sulfur is highly efficient when the gas temperature is 300 ° C. or lower, preferably lower than 300 ° C.
Chlorine in flammable gas at a temperature lower than ° C,
The sulfur content and slaked lime are combined with high efficiency, and the combined matter and dust are collected by the bag filter 4.

Accordingly, clean flammable gas D, which is detoxified and dust-free, is recovered. This flammable gas D is used in the municipal solid waste pyrolysis gasification system. As a combustible gas for the melting furnace that melts the bottom ash generated in the above, and as a drying medium for the refuse drying device,
It is provided as combustible gas that is burned in a combustion furnace constituting a part of the power generation system, and is effectively used.

As described above, in the present embodiment, the membrane sections formed by connecting the water pipes through which the cooling water flows are separated from each other in an annular manner are multiplexed, and the space between the membrane sections 8 and 9 through which the flammable gas flows is used. Since the passage 12 is used, by setting the interval between the membrane portions 8 and 9 to be optimal, the flow rate of the combustible gas flowing through the flue 12 can be set to a predetermined value without forming a narrow portion in the entire flue 12. The membrane sections 8, 9 on both sides forming a flue 12 while being made fast
Are opposed to each other as heat transfer surfaces, and a predetermined heat transfer area is secured. Therefore, it is possible to prevent clogging of the flue 12 and deterioration of the cooling performance.

Here, if the flue 12 is clogged, the hammering device 13 may be used to perform hammering. By the hammering of the hammering device 13, the vibration of the hammering is transmitted to both the membrane parts 8, 9, and it is possible to remove the clogging of the flue 12 without stopping the operation. Therefore, according to this embodiment, the operation efficiency is improved.

Further, since the hammering device 13 is configured to be able to transmit vibrations caused by hammering to both of the membrane portions 8 and 9 at the same time, the hammering device is provided by the number of the membrane portions 8 and 9 (this embodiment). In this case, it is not necessary to provide two parts in one place, and cost reduction is achieved.

As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the cooling medium of the gas cooling device is cooled. Although it is water, it may be another cooling liquid or a cooling gas.

In the above embodiment, the convection type gas cooling device 3b has two membrane portions, but may have three or more membrane portions. However, in the case of three or more layers, the heat transfer amount (degree of cooling) differs between the membrane portions, so that the double layer is particularly preferable.

Further, in the above-described embodiment, the application to the convection type gas cooling device 3b is described as particularly suitable, but the invention is similarly applicable to the radiation type gas cooling device 3a and the economizer 3c. In short, the invention is applicable to all gas cooling devices that cool exhaust gas flowing through a flue by contacting the exhaust gas with a pipe through which a cooling medium flows.

Further, in the above embodiment, the application to the gasifier 1 for pyrolyzing and gasifying the municipal waste A is described. For example, the same applies to the gasifier for pyrolyzing and gasifying coal. Applicable to

[0050]

According to the gas cooling apparatus of the present invention, a membrane section formed by connecting pipes in which a cooling medium flows in a ring-like manner and separated from each other is multiplexed, and a flue for flowing exhaust gas is provided between the membrane sections. By optimally setting the interval between the exhaust gas, it is possible to increase the flow velocity of the exhaust gas flowing through the flue to a predetermined speed without forming a narrow portion in the entire flue, and to make the membrane on both sides forming the flue. Since the opposing surfaces of the portions are configured as heat transfer surfaces to secure a predetermined heat transfer area, it is possible to prevent clogging of the flue and deterioration of cooling performance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a municipal solid waste pyrolysis gasification system to which a gas cooling device according to the present invention is applied.

FIG. 2 is a longitudinal sectional view showing a convection gas cooling device in FIG. 1;

FIG. 3 is a plan view showing the convective gas cooling device in FIG.

FIG. 4 is a diagram showing a PP arrow in FIG. 2;

FIG. 5 is an enlarged view illustrating a hammer seat of the hammer in FIG. 4;

FIG. 6 is a view shown by arrows QQ in FIG. 5;

FIG. 7 is a cross-sectional view showing a convective gas cooling device according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gasification furnace, 3b ... Convection type gas cooling device (gas cooling device), 8, 9 ... Membrane part, 8a, 9a ... Water pipe (cooling medium pipe), 12 ... Flue, 13 ... Hammering device.

Claims (7)

[Claims] 1. A gas cooling apparatus for cooling exhaust gas flowing through a flue by bringing the exhaust gas into contact with a pipe through which a cooling medium flows, comprising: a plurality of said pipes; A gas cooling device comprising: a plurality of membrane sections; and a flue through which the exhaust gas flows between the membrane sections. 2. The membrane device according to claim 1, wherein the membrane sections on both sides forming the flue are arranged in a staggered arrangement in which the pipes are alternately arranged along the circumferential direction. Gas cooling device. 3. The gas cooling device according to claim 1, wherein the multiple membrane portions are double. 4. The flow rate of the exhaust gas in the flue is 5 m
/ S to 15 m / s.
The gas cooling device according to claim 1. 5. The gas cooling device according to claim 1, further comprising a hammering device capable of hammering the membrane portion. 6. The gas cooling device according to claim 5, wherein the hammering device is configured to be able to hammer the multiple membrane portions at the same time. 7. The gas cooling device according to claim 1, wherein the exhaust gas is a combustible gas discharged from a gasification furnace that pyrolyzes and combustibles into gas. .