JP2002273151A - Apparatus for cleaning exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas cleaning apparatus which can remove soot and trace quantity components contained in exhaust gas discharged from a small-size boiler, a diesel engine, etc., and clear the exhaust gas. SOLUTION: A cleaning column 11 in which a cleaning solution stored in a liquid storage part 8 is circulated by the actuation of a circulating cleaning solution pump 9, sprayed from an upper spray nozzle 10, and contacted with the exhaust gas to clean the exhaust gas, a cartridge type filter 12 for catching components which are removed from the exhaust gas and contained in the cleaning solution which cleaned the exhaust gas in the cleaning column 11, a cooler 13 for cooling the cleaning solution which cleaned the exhaust gas in the cleaning column 11, and a heat exchanger 14 for the heat exchange between the exhaust gas introduced into the cleaning column 11 and the exhaust gas which is cleaned in the cleaning column 11 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus.

[0002]

2. Description of the Related Art Generally, a large boiler plant is provided with an exhaust gas purifying device such as a denitration device, a desulfurization device, and a dust collecting device, but the exhaust gas discharged from a small boiler or the like is included in the exhaust gas. Currently, soot and trace components are released to the atmosphere without being removed.

On the other hand, in the case of a diesel engine for a truck or the like, for example, as shown in FIG. 6, a particulate filter 2 composed of an element such as a ceramic honeycomb filter is arranged in the exhaust passage 1 of the engine, and A backwash air nozzle 5 for blowing high-pressure air in an air tank 3 to the particulate filter 2 by opening a valve 4 is disposed downstream of the particulate filter 2, and further upstream of the particulate filter 2. Further, there is an exhaust gas purifying apparatus that forms a particulate incineration section 7 that collects particulates blown down by the backwashing of the particulate filter 2 by the backwashing air nozzle 5 and burns the particulates by the heater 6.

[0006] In the exhaust gas purifying apparatus shown in FIG. 6, during normal operation in which the particulate filter 2 is not clogged, the particulates in the exhaust gas discharged from the engine pass through the particulate filter 2. At this time, the exhaust gas is collected by the particulate filter 2 and discharged as a clean gas, and the particulates accumulate in the particulate filter 2 due to operation for a certain period of time, causing clogging and reducing exhaust resistance. When the pressure increases, the valve 4 is opened by a control signal from a control device based on a detection signal from a pressure detector (not shown),
High pressure air in the air tank 3 is blown from the backwash air nozzle 5 to the particulate filter 2 as a backwash flow,
The particulates adhering to the particulate filter 2 are blown down to the particulate incineration unit 7, and in the particulate incineration unit 7, are incinerated by the heat of the heater 6 which has been heated by energization. The clogging of No. 2 is eliminated, the exhaust resistance is reduced, and particulates can be collected again.

[0005]

However, as shown in FIG. 6, in an exhaust gas purifying apparatus using a particulate filter 2, as shown in FIG. 6, although solids such as particulates causing black smoke can be removed, exhaust gas is not removed. Minor components such as hydrocarbons (HC), carbon monoxide (CO), and heavy metals (Ni, Mg, V, etc.) contained therein cannot be removed, and there is a concern that they may affect the atmospheric environment. ing.

[0006] In order to improve the atmospheric environment, it is necessary to remove soot and trace components contained in flue gas discharged from small boilers and the like.

The present invention has been made in view of the above-mentioned circumstances, and an exhaust gas purifying apparatus capable of removing soot and trace components contained in exhaust gas discharged from a small boiler, a diesel engine, or the like and purifying the exhaust gas. It is intended to provide.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a cleaning tower for circulating a cleaning liquid stored in a liquid reservoir, spraying the cleaning liquid from above, and bringing the exhaust gas and the cleaning liquid into gas-liquid contact to clean the exhaust gas. A filter for collecting an exhaust gas removing component contained in a cleaning solution that has washed exhaust gas with a filter, and a cooler that cools the cleaning solution that has washed exhaust gas with the washing tower, according to the exhaust gas purifying apparatus. is there.

In the exhaust gas purifying apparatus, a plurality of sheave trays having a large number of exhaust gas passage holes are arranged vertically in the washing tower, and the washing liquid sprayed from above is sequentially lowered from the uppermost sheave tray. While flowing down to the sheave tray of the first stage, the exhaust gas passes through the exhaust gas passage hole of the upper stage sieve tray from the exhaust gas passage hole of the lowest stage sheave tray and rises.

[0010] It is also possible to adopt a construction in which an agent for coagulating and precipitating an exhaust gas removing component contained in the washing liquid is injected into the washing liquid extracted from the liquid reservoir of the washing tower.

Further, a heat exchanger for exchanging heat between the exhaust gas introduced into the washing tower and the exhaust gas washed in the washing tower may be provided.

According to the above means, the following effects can be obtained.

When the exhaust gas is introduced into the washing tower sprayed from above by circulating the washing liquid stored in the liquid reservoir, the exhaust gas comes into gas-liquid contact with the washing liquid, and the exhaust gas is washed. In the washing liquid having the exhaust gas washed in the tower, the exhaust gas removing component is collected by the filter, and is cooled by the cooler and circulated.

When the exhaust gas is washed in the washing tower as described above,
Not only solids such as particulates that cause black smoke in exhaust gas emitted from small boilers and diesel engines, but also trace components such as hydrocarbons, carbon monoxide, and heavy metals contained in exhaust gas It can be removed by dissolving it in the cleaning solution, which helps to improve the atmospheric environment.

Further, when the exhaust gas and the cleaning liquid come into gas-liquid contact, the temperature of the cleaning liquid rises due to the heat of the exhaust gas, evaporates and escapes from the cleaning tower, and the cleaning liquid may run short.
By cooling and circulating the cleaning liquid with a cooler, the cleaning liquid that evaporates and escapes can be minimized, and the water contained in the exhaust gas is introduced into the cleaning tower. Almost no water replenishment equipment is required, and the temperature of the entire apparatus is kept low, so that the washing tower and piping can be formed of plastic-based corrosion-resistant materials, and can be mounted on automobiles etc. due to their small size and light weight. It is suitable for purifying exhaust gas discharged from small boilers, diesel engines, and the like.

In the exhaust gas purifying apparatus, a plurality of sheave trays having a large number of exhaust gas passage holes are arranged vertically in the washing tower, and the washing liquid sprayed from above is sequentially discharged from the uppermost sieve tray to the lower one. The efficiency of gas-liquid contact between the exhaust gas and the cleaning liquid is reduced by flowing the exhaust gas from the exhaust gas passage hole of the lowermost sieve tray through the exhaust gas passage hole of the upper sieve tray while flowing down to the sieve tray of the lower stage. And the washing tower can be further miniaturized,
This leads to downsizing of the entire device.

[0017] Further, when a chemical for coagulating and precipitating an exhaust gas removing component contained in the cleaning liquid is injected into the cleaning liquid extracted from the liquid storage section of the cleaning tower, the exhaust gas contained in the cleaning liquid after cleaning the exhaust gas with the cleaning tower is provided. The removal component can be easily collected by the filter, and the cleaning liquid circulated and sprayed from above can always be kept at a state of a specified concentration or less, so that the exhaust gas can be efficiently cleaned.

Further, if a heat exchanger for exchanging heat between the exhaust gas introduced into the washing tower and the exhaust gas washed in the washing tower is provided, high-temperature exhaust gas discharged from a small boiler, a diesel engine, or the like, is provided. The temperature can be reduced and the exhaust gas can be introduced into the washing tower. At the same time, the temperature of the exhaust gas washed in the washing tower can be increased and released to the atmosphere, thereby preventing the generation of white smoke.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show an embodiment of the present invention, in which a cleaning liquid stored in a liquid reservoir 8 is circulated by the operation of a circulating cleaning liquid pump 9 so that an upper spray nozzle 1 is formed.
A cleaning tower 11 for spraying the exhaust gas and the cleaning liquid in gas-liquid contact with the cleaning liquid to wash the exhaust gas, a cartridge type filter 12 for collecting an exhaust gas removing component contained in the cleaning liquid having the exhaust gas washed by the cleaning tower 11, A cooler 13 for cooling a cleaning liquid that has cleaned exhaust gas in the cleaning tower 11;
The exhaust gas purifier 15 includes a heat exchanger 14 for exchanging heat between the exhaust gas introduced into the exhaust gas 1 and the exhaust gas washed in the washing tower 11.

As shown in FIGS. 2 and 3, the spray nozzle 10 disposed above the washing tower 11 is attached to a water sprinkling pipe 17 branched from a washing liquid circulation pipe 16 into a plurality of parts. As shown in FIGS. 1, 4 and 5, a plurality of sheave trays 19 having a large number of exhaust gas passage holes 18 are vertically arranged inside the washing tower 11, and sprayed from a spray nozzle 10 above. The exhaust gas passes through the exhaust gas passage holes 18 of the upper sheave tray 19 sequentially from the exhaust gas passage holes 18 of the lower sheave tray 19 and rises while the cleaning liquid flowing down from the uppermost sheave tray 19 to the lower sheave tray 19 sequentially. I let you go.

The washing liquid extracted from the liquid storage section 8 of the washing tower 11 is injected with a chemical (eg, ferric chloride, sulfuric acid, or the like) that coagulates and precipitates an exhaust gas removing component contained in the washing liquid. is there.

The cooler 13 has a cooling water circulation pump 20
The cooling water is cooled in a water cooler 21 by using the cooling water circulated by the operation of the cooling medium as a cooling medium. The water cooler 21 is a truck or the like. In the case of the automobile described above, an existing radiator or the like can be used.

The exhaust gas purifying device 15 can be housed in a package as a single unit. However, when the exhaust gas purifying device 15 is mounted on an automobile such as a truck, each component is disposed at a required position of a chassis forming a carrier. And they may be connected by piping.

In FIG. 1, reference numeral 22 denotes a filter replacement valve which is provided on the inlet side and the outlet side of the filter 12 and is closed only when the filter 12 is replaced. The cleaning liquid collection valve 24 which is opened only when the supply water is supplied is a supply water supply valve which is opened only when the supply water is supplied.

Next, the operation of the illustrated example will be described.

When high-temperature exhaust gas discharged from a small boiler, a diesel engine, or the like passes through the heat exchanger 14,
Heat exchange is performed with the washed exhaust gas described later, and the temperature is lowered to be introduced into the washing tower.

In the cleaning tower 11, the cleaning liquid stored in the liquid reservoir 8 is circulated by the operation of the circulating cleaning liquid pump 9 and sprayed from the upper spray nozzle 10, and the exhaust gas introduced into the cleaning tower 11 and the cleaning liquid The gas and liquid come into contact with each other, and the exhaust gas is washed. In the washing liquid having the exhaust gas washed in the washing tower 11, the exhaust gas removing component is collected by the filter 12, and is cooled by the cooler 13 and circulated.

The cooling water whose temperature has been raised by cooling the washing liquid in the cooler 13 is guided to a water cooler 21 by the operation of a cooling water circulation pump 20, and is cooled and circulated in the water cooler 21.

When the exhaust gas is washed in the washing tower 11 as described above, not only solids such as particulates causing black smoke of the exhaust gas discharged from the small boiler or the diesel engine, but also the exhaust gas is contained in the exhaust gas. Trace components such as hydrocarbons, carbon monoxide, and heavy metals can be dissolved in the cleaning solution and removed, which is useful for improving the atmospheric environment.

Further, when the exhaust gas comes into gas-liquid contact with the cleaning liquid, the temperature of the cleaning liquid rises due to the heat of the exhaust gas, evaporates and escapes from the cleaning tower 11, and the cleaning liquid may run short. By cooling and circulating the water in the vessel 13, the cleaning liquid that evaporates and escapes can be minimized, and the water contained in the exhaust gas is introduced into the cleaning tower 11, and the continuous water is used. The replenishment equipment is almost unnecessary, and the temperature of the entire apparatus is kept low, so that the washing tower 11 and the pipes can be formed of a plastic-based corrosion-resistant material. It is suitable for purifying exhaust gas discharged from small boilers, diesel engines, and the like.

In the washing tower 11, a plurality of sheave trays 19 having a large number of exhaust gas passage holes 18 are provided vertically, and a washing liquid sprayed from an upper spray nozzle 10 is supplied from the uppermost sheave tray 19 to the washing tower. Since the exhaust gas passes from the exhaust gas passage hole 18 of the lowermost sheave tray 19 through the exhaust gas passage hole 18 of the upper sheave tray 19 sequentially while flowing down to the lower sheave tray 19, The efficiency of the gas-liquid contact between the exhaust gas and the cleaning liquid is high, which is advantageous for reducing the size of the cleaning tower 11, which leads to a reduction in the size of the entire apparatus.

Further, a chemical (eg, ferric chloride, sulfuric acid, or the like) for coagulating and precipitating an exhaust gas removing component contained in the cleaning liquid is introduced into the cleaning liquid extracted from the liquid reservoir 8 of the cleaning tower 11. Therefore, the exhaust gas removing component contained in the cleaning liquid obtained by cleaning the exhaust gas in the cleaning tower 11 can be easily collected by the filter 12, and the cleaning liquid circulated and sprayed from the upper spray nozzle 10 always has a concentration equal to or lower than a specified concentration. In this state, the exhaust gas is efficiently cleaned. still,
In addition to the above agents, calcium carbonate (CaC)
O ₃ ), magnesium hydroxide (Mg (OH) ₂ ) or the like is added to positively absorb sulfur oxides (SOx) in the exhaust gas, or nitrogen oxides (NO
It is also possible to positively absorb x).

Further, since a heat exchanger 14 for exchanging heat between the exhaust gas introduced into the washing tower 11 and the exhaust gas washed in the washing tower 11 is provided, the exhaust gas discharged from a small boiler, a diesel engine or the like is provided. It is possible to lower the temperature of the high-temperature exhaust gas and introduce it into the washing tower 11, and to prevent the generation of white smoke by increasing the temperature of the exhaust gas washed in the washing tower 11 and releasing it to the atmosphere.

When the exhaust gas purifying device 15 is mounted on an automobile such as a truck, when refueling at a gas station or the like, the cleaning liquid collecting valve 23 is opened as necessary depending on the degree of contamination of the cleaning liquid, and the cleaning liquid is supplied to a drum can. And the like, separately performing drainage treatment, opening the makeup water supply valve 24, supplying makeup water, and renewing the cleaning liquid, and the filter 12 may be appropriately adjusted according to the degree of clogging. The cartridge may be replaced by closing the filter replacement valves 22 provided on the inlet side and the outlet side of the filter 12.

In this way, soot and trace components contained in exhaust gas discharged from a small boiler, a diesel engine or the like can be removed, and the exhaust gas can be purified.

It is to be noted that the exhaust gas purifying apparatus of the present invention is not limited to the illustrated example described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

[0038]

As described above, according to the exhaust gas purifying apparatus of the present invention, soot and trace components contained in exhaust gas discharged from a small boiler, a diesel engine or the like can be removed. An excellent effect that cleaning can be achieved can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 2;

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 1;

FIG. 5 is a view taken in the direction of arrows VV in FIG. 1;

FIG. 6 is a schematic configuration diagram illustrating an example of a conventional exhaust gas cleaning device used for a diesel engine or the like.

[Explanation of symbols]

 Reference Signs List 8 Liquid reservoir 9 Circulating cleaning liquid pump 10 Spray nozzle 11 Cleaning tower 12 Filter 13 Cooler 14 Heat exchanger 15 Exhaust gas purifier 18 Exhaust gas passage hole 19 Sheave tray 20 Cooling water circulation pump 21 Water cooler

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F23J 15/04 F term (Reference) 3G090 AA06 EA01 3G091 AA02 AA18 AB15 BA00 BA15 BA19 BA36 CA08 CA15 HB01 3K070 DA07 DA11 DA37 DA38 DA40 DA48 4D002 AA02 AA12 AA28 AC01 AC10 BA02 BA14 CA01 CA02 DA05 DA06 DA12 DA16 DA17 DA26 DA35 EA02 HA08 4D032 AC07 AC11 BA03 BB05

Claims (4)

[Claims] 1. A cleaning tower for circulating a cleaning liquid stored in a liquid reservoir and spraying the cleaning liquid from above, cleaning the exhaust gas by gas-liquid contact between the exhaust gas and the cleaning liquid, and a cleaning tower for cleaning the exhaust gas with the cleaning tower. An exhaust gas purifying apparatus, comprising: a filter that collects exhaust gas removing components to be removed; and a cooler that cools a cleaning liquid that has cleaned exhaust gas in the cleaning tower. 2. A plurality of sheave trays having a large number of exhaust gas passage holes are vertically arranged inside a washing tower, and a washing liquid sprayed from above flows down from the uppermost sheave tray to the lower sheave tray sequentially. 2. The exhaust gas purifying apparatus according to claim 1, wherein the exhaust gas is passed through the exhaust gas passage holes of the upper sheave tray sequentially from the exhaust gas passage holes of the lowermost sheave tray and is raised. 3. The exhaust gas purifying apparatus according to claim 1, wherein an agent for coagulating and precipitating an exhaust gas removing component contained in the cleaning liquid is injected into the cleaning liquid extracted from the liquid reservoir of the cleaning tower. 4. The exhaust gas purifying apparatus according to claim 1, further comprising a heat exchanger for exchanging heat between the exhaust gas introduced into the washing tower and the exhaust gas washed in the washing tower.