JPH0134646B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method and apparatus for cooling and neutralizing acid gas using the process of contacting the acid gas with a liquid spray. The problem of releasing industrial gases containing high proportions of harmful substances into the atmosphere has long been recognized.
Acid gases such as sulfur oxides, nitrogen oxides and hydrogen halides are particularly common and undesirable components of industrial emissions. If these gases are released into the atmosphere, they will condense on water droplets to form strong acids, and if blown away by the wind, these droplets can attack metal parts even miles from the factory location. Causes severe corrosion to products and machinery. Direct danger to flora and fauna life within such areas has been established. As a result, local and national regulations in the United States and various other countries have placed increasingly stringent limits on the allowable acid gas content of vented gases. Various methods have been proposed to deal with this situation, but until now the method has been to treat a large volume of hot discharged gas containing a relatively high concentration of acid gas, and to reduce the acid gas content to an acceptable level. reduced to
No single method has been completely successful in dealing with the three-part problem of sustaining economic operation. It has long been known to purify gas streams by contacting them with solid absorbent materials that are capable of selectively reacting with the gas stream and/or physically absorbing impurities from the gas stream. It was hot. Absorbing materials can be used, for example, as described in U.S. Pat.
Generally, the filter cake was used in the form of a bed of particulate material, as taught in US Pat. However, many problems were associated with such methods. Packed absorption columns of the type previously used have been limited in use to the treatment of relatively small volumes of gaseous materials. Large volumes could not be efficiently processed through fixed bed columns due to the large pressure drops that occur before and after filling. When contaminant gases are present at concentrations below about 400 ppm, the large amount of power required to flow the gas through the bed has made such processing uneconomical. Additionally, fixed bed columns have had the problem of having a "break-through" point, ie, a point where the bed of absorbent material gradually becomes saturated and the efficiency level drops off rapidly at a certain point. If pollutant limits are exceeded at this stage,
Contaminants will escape until the system is shut down and replaced or the gas stream is sent to a new packed tower. This was just a batch operation.
As shown in U.S. Pat. No. 3,723,598,
Absorbent particulate matter in the bed is agitated due to the incoming contaminant gas stream, so that the aerated mass tends to behave more like a fluid.In fluidized bed operation, pressure drops, cross-points, and discontinuous operation occur. It was discovered that there was a serious problem. U.S. Pat. No. 2,919,174 discloses a method for removing fluoride contaminants from a gas stream that reliably avoids the high pressure drops and overshoot points of the prior art methods mentioned above. This method involves dispersing finely divided calcium carbonate (CaCO ₃ ) or other basic salts of alkali or alkaline earth metals into a gas stream containing fluoride contaminants and backing up the particle-containing air stream. It consists of feeding into a house filter, where a permeable layer of alkaline substances is generated. However, this method is disadvantageous in another respect, namely that it is limited to alkaline substances that react with the fluoride gas in the dry state. Moreover, this method requires the creation of a layer of alkaline material on the inner surface of the filter before it can take effect. "Wet processes" in which a column is filled with packing material and a liquid, such as water, through which a stream of contaminated gas is passed, are known in the prior art. Wet scrubbing the waste gas with an aqueous solution or slurry of manganese sulfate, calcium bicarbonate, lime, ammonia, and sulfite-sodium bisulfite to remove sulfur dioxide is a method of removing sulfur dioxide from the flue gas at 100°C (water and water) before absorption occurs. U.S. Pat. No. 3,551,093 ignored it as impractical because it required cooling below the boiling point of On top of that,
The high pressure drop across the packed column and the relatively slow diffusion rate of gas in the liquid phase make this method impractical for large scale operations. It has also been proposed to contact the gas with a spray of droplets containing a neutralizing agent to simultaneously cool and neutralize the hot acidic gas. In these methods, a neutralizing agent reacts with the acidic gas and increases its pH to about 7. The amount of water used in the spray or water-solids suspension is sufficient to reduce the temperature of the gas with evaporation of the water such that the reaction products and/or unreacted neutralizer are dried. Essentially complete drying must occur. Otherwise, an aqueous composition builds up on the bottom of the used equipment, which is corrosive, difficult to remove, and causes undesirable equipment downtime. The equipment used in this process is generally that used in co-current, co-downward co-current spray dryers or gas and liquid atomizers. Certain limited applications use countercurrent flow, where the gas travels upward and the liquid spray travels downward. However, this latter technique requires sufficient contact between the gas and liquid spray to achieve substantially complete neutralization and, at the same time, substantially complete evaporation of the contacting liquid. Generally unfavorable because residence time is not obtained. The problem of substantially complete drying is complicated by the fact that industrial emissions typically contain particulate matter that must also be removed. Approximately 176.6g/m ³ in standard condition
(0.5g/dscf) and the particulate concentration is high, the particulates will collide with the liquid spray resulting in agglomeration of the spray and formation of large droplets that are very difficult to evaporate. It causes generation. For example, when producing a spray with a single liquid nozzle or two liquid nozzles or a rotating disk, a particle size distribution of liquid particles is created. Small droplets evaporate rapidly, while large droplets evaporate slowly. The quench reactor must be sized to provide a "safe" spray time for complete evaporation of even large droplets. Thus, the size of the device has become excessively large, while still remaining unreliable when the nozzle or disk droplet distribution changes with time or operating conditions. For example, if the diameter of the equipment used provides a gas velocity of 182.9 cm/sec (6 ft/sec), and a 400 micron droplet is produced, then the initial downward velocity of the droplet is 182.9 cm/sec (6 ft/sec).
seconds (6 feet/second) and the terminal velocity of 152.4 cm/second (5 feet/second), or net 335.3
cm/second (11 feet/second). Evaporation time is 6
If the particle size is reduced to 40μ in the dry state, the length of the quench reactor will necessarily be approximately
It will be about 1585.0cm (52 feet). Such devices are expensive to construct and maintain and are therefore undesirable. It would be desirable to provide a device that neutralizes and cools acid gases at industrially attractive rates without the need for large equipment. Moreover, it would be desirable to provide an apparatus that neutralizes the gas and substantially completely ensures that the product gas composition is dry. According to the invention, a gas stream containing an acid gas is moved in a generally helical flow through an initial reaction chamber before a main reaction chamber to remove relatively large particles that may be present in the acid gas. remove. The upwardly moving basic acid gas, which is essentially free of these large particles, is introduced upward into the main reaction chamber and reacts with and neutralizes the acid gas therein. Contact with a spray of liquid or slurry of substance. The atomized particles of this liquid or slurry have a longer residence time in the reactor (initial reaction chamber and main reaction chamber) and move upward due to the initial upward velocity of the particles due to the pressure at the atomizing nozzle. The force of the gas balances the gravitational force in such a way that the atomized particles gradually move upward in the reactor until the water in the atomized particles is evaporated. By controlling the average particle size of the particles in the atomization and the velocity of the upwardly moving gas, substantial reductions in reactor size can be made, providing substantial economic benefits. The present invention can be incorporated as the first or last step in an integrated method for removing acid gases and particulates from a gas stream. FIG. 1 is a cross-sectional side view of the reactor of the present invention. FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. FIG. 3 illustrates the invention in an integrated manner for removing acid gases and particulates from a gas stream. The gas stream treated by the present invention typically comprises an effluent gas stream from a furnace or blast furnace or similar device. The discharged gas is introduced into the initial reaction chamber before the main reaction chamber in a manner that causes the gas to move in a spiral manner so that relatively large particles in the gas can be removed. The large solid particles present in the effluent gas are forced outward from the center of the initial reaction chamber by centrifugal force and are collected in a chamber with an opening in the inner wall at the bottom of the reaction chamber. Removal of these large particles minimizes or eliminates the formation of undesirable large droplets that form upon impact of the basic material spray with these particles. The gas is then introduced into the bottom of the main reaction chamber and contacted therein with the basic substance spray. The initial rotational motion of the gas stream brought about by introducing the gas stream tangentially into the initial reaction chamber disappears as the gas flows upward from the initial reaction chamber into the reactor; After the large particles have been removed, the gas stream is contacted by a spray of a liquid or slurry of basic material emitted from a nozzle located in the upwardly moving gas stream. If the acid gas initially introduced into the main reaction chamber is relatively free of large particles, the spray nozzle should be placed at a vertical height at or near the point where the acid gas is introduced into the reactor. can do. Alternatively, if the gas to be treated is completely free of large particles, the initial reaction step can be omitted and this gas can be introduced directly into the bottom of the reactor. In the present invention, multiple spray nozzles can be used to introduce sprays of multiple basic substances into the acidic gas. This is done using a plurality of separate initial reaction chambers in which large particles are removed from the gas and each with a spray nozzle placed upstream of the reactor. Since large droplets emitted from the nozzle travel a shorter distance from the nozzle than small droplets, large droplets are no longer generated due to collisions between large droplets emitted from different sprays. The use of multiple sprays is advantageous because it allows for more complete contact between the gas and the spray than using a single spray. Prior art methods that use downward gas flow in the reactor do not use multiple atomizing nozzles because the collision of droplets emitted from different nozzles produces large droplets. This results in the undesirable accumulation of corrosive aqueous compositions at the bottom of the reactor. Although it is preferable to create a spray of a liquid or slurry of basic material with uniform droplet size,
In practice, the droplet size varies over a relatively wide range. In the case of the prior art, the large droplets that initially moved downward passed through the entire length of the reactor without being completely evaporated and collected at the bottom, causing damage to the reactor. In contrast, in the present invention, the direction of the gravitational force acting on a droplet is opposite to the direction of the gas introduction velocity that accompanies the droplet, so that such a droplet has a longer residence time in the reactor and therefore evaporates. Put it away. Small particles that require a short residence time to evaporate actually have a short residence time. However, in all cases, the droplets completely evaporate before being ejected. Thus, essentially, the larger the particle size of the droplets dispersed due to poor functioning of the spray nozzle, the less concern there is in the method of the present invention. Gas temperature typically ranges from 121.1℃ (250〓)
The temperature range is up to 537.8℃ (1000〓), but approximately
It can range from 65.6°C (150〓) to 1648.9°C (3000〓) or more. The flow rate is 1
From a slow speed of cc/min to ^28315m3 /min (1000000
cubic feet per minute) or higher, limited only by the size and design of the main reaction chamber. Gaseous pollutants vary based on specific industrial operations. For example, fertilizer, aluminum and secondary aluminum operations generate large amounts of hydrogen fluoride and silicon tetrafluoride. Carbonization operations produce large amounts of sulfur dioxide and small amounts of nitrogen oxides. Hydrogen chloride is another byproduct of the secondary aluminum process, as well as the demagging of primary aluminum, the incineration of waste chlorinated hydrocarbons, and municipal incinerators. The gas stream also typically contains entrained particulate matter consisting of dust, unburned carbon, and various metal oxides such as silica, alumina, ferrite, and the like. In refining operations, entrained droplets of liquid hydrocarbons and derivatives may be present in the effluent gas stream. The gas stream is passed into the main reaction chamber where it is contacted with a solution or slurry of a basic substance, i.e. a compound or substance that reacts in a basic manner in water; the most common substances of this type are alkalis and alkalis. Earth metal oxides, hydroxides,
Carbonates and bicarbonates, but the present invention is not limited thereto. Particularly included within the scope of the invention are _NaOH , _Na2CO3 , _NaHCO3 ,
Na ₂ SO ₃ , KOH, K ₂ CO ₃ , KHCO ₃ , K ₂ SO ₃ ,
LiOH, _Li2CO3 , _LiHCO3 , Ca(OH) ₂ , _CaO ,
_CaCO3 , Mg(OH) ₂ , MgO, _MgCO3 , Ba
(OH) ₂ , BaO, _BaCO3 , Zn(OH) ₂ , ZnO,
_ZnCO3 , Ni(OH) ₂ , NiO, _NiCO3 , Cu(OH) ₂ ,
CuOH, Fe(OH) ₃ , ^Fe3O3 , _{FeCO3 , Fe2} ( _CO3 ) ₃
It is. The present invention also includes various ores that are composed of one or more of the above-mentioned compounds and that undergo basic reactions in water. Typical examples of such ores are kasmiin centiolite and honorite. The alkali metal compounds mentioned above, sodium, potassium and lithium compounds, are all very soluble in water and can be used as aqueous solutions. The other basic compounds listed above range from slightly soluble to substantially insoluble in cold water. These compounds can be used in fine powder form as an aqueous slurry. Slurries of calcium and magnesium compounds can be economically used in the process of the present invention. Although these solutions and slurries are typically used at or near room temperature, in the case of basic substances with marginal solubility, it is necessary to maintain the substances in solution and to avoid the frequent rises associated with the use of the slurry. It is preferred to use heated solutions to avoid clogging problems. It is preferred to heat the solution or slurry when the temperature is below about 121.1°C (250°C), particularly when the temperature is below the boiling point of water. For example, by heating the liquid under pressure, the temperature of the liquid can be increased to approximately 537.8°C.
(1000〓) to ensure that there is adequate heat in the main reaction chamber to completely flash-evaporate all of the liquid and leave a dry salt reaction product. However, it is preferred, and common in most industrial operations, that the heat provided by the gas stream itself is adequate. Therefore, for convenience in this specification of the present invention, the gas stream will be referred to as a hot gas stream. When the hot gas stream comes into contact with the aqueous solution or slurry, a rather violent reaction occurs. The water evaporates and cools the gas stream, creating strong turbulence and facilitating intimate contact between the acid gas and the basic substance.
Due to the saturated environment and high dew point of acid gases,
Acid mist forms near the spray nozzle. This results in a more complete neutralization of the acid gas and, at the same time, the formation of corresponding acid salts, in order to increase the residence time of the acid gas in the fog region in the vicinity of the nozzle.
Under the above conditions, the reaction is very rapid and the required residence time in the reactor ranges from about 1/10000 seconds to less than about 2 seconds. For example, when a lime slurry is used to quench a gas stream containing hydrogen chloride, the products are salts,
Calcium chloride (CaCl ₂ ). The concentration of the basic material in the aqueous solution or slurry and the relative proportion of the hot released gas to the solution or slurry are determined to ensure that at any given time a stoichiometric equivalent or excess of the basic material is the dominant reaction. All the water in the room and to be evaporated is "dry"
is a variable that can be adjusted to form a product gas. For example, for a given flow rate of emitted gas with a given acid gas concentration, the proportion of additional basic material required to achieve a stoichiometric equivalent or excess can be calculated in a conventional manner.
Based on the flow rate and temperature of the emitted gas, it is also possible to calculate the volume of water or aqueous solution that can be heated and evaporated by the gas stream. To take into account inefficient thermal contact, an appropriate flow rate of the liquid can be selected with a certain margin of error. The concentration of basic material in the solution or slurry required to provide the additional proportion of basic material calculated above is then determined. If the liquid flow rate is increased without exceeding the rate at which the liquid can be heated and completely evaporated, the concentration of the basic substance can be correspondingly reduced. When the gas stream leaves the reactor of the present invention,
The temperature is typically between about 37.8°C (100°) and 260.0°C (500°) and substantially free of acid gases. The acid salts formed in the main reaction chamber are entrained in the neutralized gas stream and treated in the manner described below. In one aspect of the invention, the initial effluent gas stream is routed to branch pipes that create a plurality of smaller effluent gas streams. Each discharged gas stream is subjected to a whirlwind motion into a separate initial reaction chamber where large particles are separated. In each of these initial reaction chambers, the hot gas is contacted with a spray of a liquid or slurry of basic material to neutralize the acid gas therein. Operating in this manner has the added advantage of increasing the capacity of a given reactor and of using multiple independent sprays of the liquids or slurries. This minimizes the formation of large droplets due to the collision of droplets of basic liquid or slurry emitted from different nozzles;
Alternatively, they can be prevented and at the same time increase the reaction efficiency obtained with improved gas-liquid contact. Next, the present invention will be described with reference to the accompanying drawings. Reactor 10 includes a main reaction chamber 12 and a plurality of initial reaction chambers 14, 16, 18, and 20. The discharge gas S ₁ is passed through a branch pipe 2 having three inner walls 25, 26 and 27 defining inlets 28, 30 and 32 to the initial reaction chambers 14, 16, 18 and 20, respectively.
Introduced during 4th. The released gas is in each initial reaction chamber,
Since the gas is introduced tangentially to the inner wall, the introduced gas moves tangentially along the inner wall of each initial reaction chamber with circular motion, and large particles in the gas move toward the wall. are collected in conduits 34, 36, 38 and 40. The upwardly moving gas streams indicated by arrows 42 and 44 are connected to ventilates 66 and 68.
contact with a spray of a liquid or slurry of basic material emitted from spray nozzles 46 and 48 located within the base material. As shown, the spray nozzles 46 and 48 each have a conduit 50 or 52 for introducing a gas such as pressurized air, and a conduit 54 for introducing a liquid or slurry of basic material.
or 56, consisting of two liquid atomizers. Air and the liquid or slurry are passed through the nozzle 58
or mixed at the outlet of 60, gas stream 42 or 4
4, and generally into droplets having a particle size within the range of about 20μ to about 200μ. obtain the desired average droplet size and approximately 61.0 cm/sec (2 ft/sec).
seconds) ~ 304.8 cm/sec (10 ft/sec), preferably about 91.4 cm/sec (3 ft/sec) ~ 182.9 cm/sec
To obtain an initial upward spray velocity in the range of 6 ft/s, the nozzle pressure was adjusted to approximately 2.8 Kg/cm ² (40
lb/in2) to 14.1Kg/ ^cm2 (200 lb/in2) gauge pressure, preferably 2.8Kg/cm2
Maintain between 40 lbs/in ² (cm 2 ) and 70 lbs/in ² (4.9 Kg/cm 2 ) gauge pressure. Each spray nozzle 46, 48, 62 and 64 is connected to the entire reactor 10.
so that the contact time between the spray and the upwardly moving gas can be adjusted as desired.
Vertical adjustments can be made within each initial reaction chamber. Generally, it is preferred that the nozzle head be located at or near the ventilate cross sections, such as ventilary cross sections 66 and 68, in each initial reaction chamber. By operating in this manner, the spray and gas are brought into contact first after the large particles have been removed from the gas, and each spray is independent of each other so that no large particles due to droplet agglomeration occur. Minimize droplet formation. The respective sprays and hot gases then enter the main reaction chamber 12;
In this process, neutralization of the acid gas is substantially completed. Referring to FIG. 3, this figure illustrates a representative integrated method for removing acid gas from a discharge gas stream in accordance with the present invention. The gas stream S ₂ exiting the reactor 10 is forced into a downward flow via conduit 101 into a mixing zone 103 (indicated by dotted lines), where particulate matter capable of absorbing residual acid gases is introduced into the gas stream. to infuse or introduce. Although the term "area" is used herein for purposes of discussion, this need not be a structure that can be inherently defined. The particulate material can be blown or otherwise introduced in a downward flow into the gas stream from reactor 10 at one or more points along conduit 101 in an amount sufficient to absorb residual acid gas. A preferred method of adding the particulate material is by slowly feeding it from container 105 into conduit 107 and mixing it with secondary air introduced via conduit 109 to suspend the particles. The mixed stream of particles and air is then injected through conduit 111 into the waist of a ventilator 113 mounted within conduit 101 . Particularly preferred absorbent materials for the method of the invention are kasumii stentiolite and honorite. The use of nephrite to absorb small amounts of residual acid gas from large volume effluent gas streams is disclosed in more detail in U.S. Pat. Please also refer to the disclosure. Kasumiishi
The above-mentioned US Pat. No. 3,808,774 for in-situ water activation of centiolite is particularly suitable for the present invention. In detail, US Pat. No. 3,808,774 discloses that acidic gas emissions of about 100 to 500 ppm are removed from a high-temperature emitted gas stream by (1) quenching the gas stream with water to cool it and adding moisture to it ( 2) Granular Kasumiishi with a particle size of about 5 to 20μ
(3) the gas stream containing the nematode particles is injected into the baghouse filter to absorb the moisture and acid gases absorbed therein; It also explains how to remove particulate matter through a process. As described above, the gas stream _S2 exiting reactor 10 typically has a temperature of about 37.8°C (100°C) to
The temperature is 260.0℃ (500℃), it is humid, and the residual acid gas content is about 100 to 500ppm.
Gas streams are thus ideally suited for carrying out the above method. Consistent with this, the humid gas stream moistens and activates the granular nephrite, which serves to promote selective absorption of acid gases. Activation and absorption occur very quickly and are controlled by gas flow and entrained scum.
Ideally, the process is complete by the time the centipedestone reaches the device that separates the granules. The activation rate of gypsophila appears to depend at least somewhat on the relative humidity of the gas stream, with activation times on the order of 1/1000 of a second when the relative humidity is 20-30% or higher. Although the activation time becomes even shorter when the relative humidity is high, in the absorption step the amount of moisture introduced into the gas stream in the flow reactor 10 is controlled such that the relative humidity of the air stream _S2 does not exceed about 50%. Control. The reason for this is that at higher relative humidity, clogging of entrained particulates is more likely to occur along the flow path and especially in the baghouse filter. Once activated, the granular gypsophila centigrade absorbs acid gases from a gas stream in about 0.01 to 3.0 seconds. The method of the present invention for removing residual acid gas emissions has been found to be about 95 to 99% efficient and economical in removing acid gases present at concentrations of about 100 to 500 ppm. Since this absorption process is essentially a surface phenomenon, only a relatively small portion of the total particulate matter, about 7 to 15% by weight, is actively used, and high concentrations of acid gas It is not economical to use this method when
When calculating the addition rate of particulate material required for approximately stoichiometric equivalence based on the concentration of acid gas and the flow rate of the gas stream, only 7 to 15
It must be taken into account that only the percentage by weight is effective in absorbing acid gases. However, selective and efficient absorption methods can be used to purify acid gas residues by first using a quench-reaction step that uses essentially all of the basic material to remove most of the acid gases. The process becomes economical. The overall efficiency of the first stage, the main reaction chamber--quenching step, and the second stage, the introduction of granular nephelinite or similar material, in removing acid gas emissions is as high as 99.9%. A preferred method of separating a gas stream from particulate matter entrained in the gas stream is disclosed in the above-mentioned U.S. Pat.
Batsuku house described in specification No. 3808774
This is the use of filter 115. Residual acid gases and some moisture are removed from the gas stream for absorption by particulate matter before reaching the baghouse filter, meaning that corrosion of the filter is minimized. Reduction of moisture in the gas stream is also important to reduce the conditions for fog or haze formation near the exit of the gas stream. Moreover, the Batughaus filter 115 not only removes particulate nephelinite or similar materials along with moisture and acid gases absorbed therein, but also removes the particles originally present in the entrained salt particles and effluent gases leaving the first stage process. It also removes other particles that were present. The exhaust air stream S ₄ is therefore generally exhausted to the atmosphere whenever it leaves the baghouse. As previously pointed out, the nephelinite, honorite or similar materials used in the absorption step of the system of the invention carrying out an integrated process may also be used as basic material for the quenching-reaction step. Can be done. The use of nephelinite, honorite or similar natural ores as the basic material in the first stage as well as the absorbent material in the second stage of the process of the invention is particularly advantageous in the gas production industry. Particulate matter containing salt by-products and absorbed acid gases from the first stage, collected in the baghouse, can be combined and recycled directly into the glassmaking furnace. The high temperature of the furnace promotes the decomposition of the reaction products of the ore and acid gas, regenerating the ore and acid as raw materials for glass-making operations. Example 1 This example demonstrates that the present invention substantially reduces reactor size without adversely affecting the desired neutralization process. The data in Table 1 provides a comparison between the upward co-current flow process of the present invention and the conventional downward co-current flow process. In a typical neutralization method, the incoming hot acid gas has a temperature of about 1000°C, while the maximum size of the atomized droplets is about 400μ. The initial velocity of the spray exiting the nozzle is approximately 182.9 cm/sec (6 feet/sec);
The terminal velocity due to gravity, on the other hand, is about 152.4 cm/sec (5 feet/sec).

Table 1 The data in Table 1 show that with the present invention a much smaller reactor can be used to obtain the same degree of dryness as is obtained with unsuitable cocurrent flow reactors. Moreover, in the upward flow reactor of the present invention, the large droplets reside in the reactor for a longer time than the small droplets, favoring the total drying of the product gas, whereas in the downward flow reactor , the residence time in the reactor for large droplets is shorter than for small droplets. Therefore, the probability of liquid entering downstream processing steps is much higher in a downward flow reactor.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of the reactor of the present invention, FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1, and FIG. 3 is a cross-sectional view for removing acid gases and particles from a gas stream The process of doing this is shown below. 10 is a reactor, 12 is a main reaction chamber, 14, 16,
18, 20 are initial reaction chambers, 24 are branch pipes, 25,
26, 27 are inner walls, 28, 30, 32 are inlets,
34, 36, 38, 40, 50, 52, 54, 5
6, 101, 107, 109 are conduits, 42, 4
4,111 is an arrow indicating the direction of movement of airflow; 46,
48, 58, 60, 62, 64 are nozzles, 66,
68, 113 is a bench unit, 103 is a mixing area, 105 is a container, 115 is a filter, S ₁ ,
S ₂ , S ₃ , and S ₄ are gas flows.

Claims (1)

[Scope of Claims] 1. (a) introducing a discharged gas containing particles and acidic components into an initial reaction chamber; (b) directing the gas upwardly through the initial reaction chamber in a tapering spiral flow; (c) collecting the particles separated from the gas in the initial reaction chamber; (d) transferring the released gas from the initial reaction chamber to a main reaction chamber; e) introducing a spray of a basic substance in a cocurrent direction with the upwardly moving effluent gas at a location where said effluent gas passes into the main reaction chamber after its spiral flow; (f) said gas; (g) atomizing the basic substance by controlling the residence time of the released gas in the main reaction chamber while moving the acidic component upward in the main reaction chamber; (h) evaporating substantially all of the basic substance spray to form a dry stream entrained with the acid salt, and the dry stream being substantially free of acid gases; (i) the gas from the main reaction chamber is at a temperature of 37.8°C to 260°C and a relative humidity of 37.8°C to 260°C; treatment of emitted gases containing particles and acidic components, characterized in that: (j) introducing an absorbent material into the gaseous stream to absorb residual acidic gases; how to. 2 distributing the emitted gas into multiple gas streams;
2. The method of claim 1, wherein each of said gas streams is directed into one of a plurality of said initial reaction chambers and each of said gas streams is contacted with a separate spray of basic material. 3. The method of claim 1, wherein the heat required to evaporate substantially all of the basic material is provided by the venting gas. 4. The method of claim 1, which includes heating the basic substance. 5. The method of claim 1, wherein the basic substance contains a compound of an alkali metal selected from the group consisting of calcium, magnesium and mixtures thereof.