MXPA96002039A - Procedure for the deulfuration of degreased gas containing sulfur acid gas - Google Patents

Abstract

The present invention relates to a process for the desulfurization of a waste gas containing sulfurous acid gas by blowing waste gas to make contact within an absorption liquid through a plurality of spray tubes, where they are controlled in a correlative and specific manner, several operating conditions to carry out the desulfurization in a stable manner at minimum costs.

Description

PROCEDURE FOR THE DESULFURATION OF DISPOSAL GAS CONTAINING SULFUR ACID GAS BACKGROUND OF THE INVENTION This invention relates to a process for the desulfurization of a waste gas containing sulfuric acid gas by contact with an absorption liquid. A desulphurisation process is known in which a waste gas containing sulfurous acid gas (sulfur dioxide) is blown into a reservoir of an absorption liquid contained in a reaction vessel through a plurality of dispersion pipes. gas (sprinkler tubes) each of which extends vertically downwardly from a partition plate within the absorption liquid and has a side peripheral wall provided with a multiplicity of gas injection orifices in a lower portion thereof; so that the waste gas is desulfurized by contact with the absorption liquid and wherein the resulting desulfurized gas is passed into an upper space defined between the partition plate and the liquid level of the absorption liquid and is discharged from the container of reaction (3P-B-3-70532 and 3P-A-3-72913). The known method, however, has problems since relatively high costs are required to operate the procedure and to construct the apparatus for the procedure. same and that the procedure is not susceptible of being executed in a stable manner for a long period.

BRIEF DESCRIPTION OF THE INVENTION Therefore, it is the main object of the present invention to provide a process that can desulfurize a waste gas containing sulphurous acid gas at a low operating cost in a stable manner. In achieving the above object, a process for the desulfurization of a waste gas containing sulphurous acid gas is provided according to the present invention, wherein said waste gas is blown into a reservoir of a stirred absorption liquid. , contained in a reaction vessel and having a liquid level, through a plurality of gas dispersion pipes each extending vertically downwards from a partition plate into the absorption liquid and each having a lateral peripheral wall provided with a multiplicity of gas injection orifices in a lower portion thereof, so that said waste gas is desulfurized by contact with said absorption liquid and the resulting desulfurized gas is passed into an upper space defined between the dividing plate and the liquid level of said absorption liquid, characterized in that said injection orifices gas supply of each of said pipelines Gas dispersion are aligned substantially horizontally; in which every two injection holes < The gas diaphragms of each of the gas dispersion pipes are separated from each other so that, when each of the two gas injection holes is considered as a circle having the same area as the area thereof. , the distance P between the centroids of said two adjacent gas injection orifices satis the following condition: 1. 15 P / D 6 wherein D is a diameter of one of said two circles that is smaller than the other; in which the maximum speed Vm? > < of said waste gas passing through each of the gas injection orifices is controlled so that they are satis under the following conditions: And > ? ». 5S Y = 24S 0.05 < < .1.0 0.005 S 0.06 wherein Y represents a pressure of said waste gas required to carry out the desulfurization and S represents a value obtained by dividing the dynamic pressure of said gas 1+ of waste injected through the gas injection port at said maximum velocity Vm? H between the density of the absorption liquid; wherein said gas dispersion pipes are arranged so that the minimum distance Lx between two adjacent dispersion pipes satis the following copdic. ion: 1. 5 i L: t / S < 10.0 where S is as defined above; and wherein said gas injection orifices of each of said gas dispersion pipes are located such that the average distance L xx between the liquid level of said absorption liquid in the state in which no gases are injected into the gas. same and the center of each of the gas injection holes satisfy the following conditions: 2 < LXI / S < twenty where S is as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiments of the invention that follow, when considered in light of the accompanying drawings in which: Figure 1 is a view in cross section, in elevation showing diagrammatically only one embodiment of a desulfurization apparatus suitable for carrying out the method of the present invention; Figure 2 is a developed elevation view, schematically showing one embodiment of the gas injection port arrangement of a spray tube; Figure 3 is a view similar to Figure 2 showing another embodiment of the gas injection orifice arrangement of a spray tube; Figure 4 is a cross-sectional view, in elevation, similar to Figure 1, showing diagrammatically another embodiment of a desulfurization apparatus suitable for carrying out the process of the present invention; and Figure 5 is a graph showing a relationship between the waste gas pressure required for desulfurization and the S value.

DETAILED DESCRIPTION OF. THE PREFERRED MODALITIES OF THE INVENTION Referring first to Figure 1, generally designated 1 is a desulfurization apparatus suitable for carrying out the process of the present invention. The apparatus has a housing member 2 within which first and second partition plate members 3 and .14 are positioned to divide the interior space therein into first lower chamber 4, a second intermediate chamber 5 and a third chamber. upper 15. Each of the partition plate members 3 and 14 may be a horizontal plate or a plate gradually inclined or stepped. An inclined plate is the one generally used as the partition plate member 14. The first chamber 4 contains a reservoir of an absorption liquid L so that an upper space B is defined on the liquid level LS of the absorption liquid L. A gas inlet port 6 is provided in the second chamber 5 for introducing the waste gas to be treated in the second chamber 5. A plurality of gas dispersion tubes (sprinkler tubes) 7 are secured to the partition plate 3 and extend vertically downwardly into the first chamber 4 so that the waste gas introduced into the second chamber 5 is blown into the absorption liquid L through the sprinkler tubes 7. Each one of the sprinkler tubes 7 has a side peripheral wall provided with a multiplicity of holes- > gas injection horizontally aligned & in a lower portion thereof. Designated as Ul is a liquid level of the absorption liquid L in the state where no gas is fed to the sprinkler tubes 7. The gas injection ports & they are located below the level of the liquid W. In this way, the waste gas fed to the spray pipes 7 is injected into the absorption liquid L through the gas injection ports & so that a layer of mixed liquid-gas phase A is formed on the surface of the absorption liquid. The sulfurous acid gas contained in the waste gas is absorbed in the absorption liquid L in this liquid-gas phase layer A. The desulfurized waste gas by contact with the absorption liquid L then flows into the upper space B on the liquid level LS. The absorption liquid L can be an aqueous calcium sulfate paste containing an absorbent such as a calcium compound, for example limestone or slaked lime. One or more sprinkler tubes 16 are provided to connect the first and third chambers 4 and 15. The third chamber 15 has a gas discharge port 9 in an upper portion thereof. In this way, the desulfurized gas in the upper space B flows upwards as well as in the direction & horizontal. During the flow of the desulfurized gas in the upper space B, a larger part of the mist and solid particles contained therein are separated from it? by gravity and by collision with sprinkler tubes 7. The desulfurized gas from which solid particles and liquid have been separated is passed through the sprinkler tubes 16 to the third chamber 15. The rising gas flow is converted in this way in a horizontal gas flow and discharged from the third chamber 15 through the outlet port 9. During the passage of the desulfurized gas through the third chamber 15, the incoming liquid and the solid particles are separated and collected in the partition plate 14. A wash liquid, such as an aqueous slurry containing calcium sulfate, the absorption liquid from which the calcium sulfate, water or seawater was separated, is supplied into a conduit 17 to the third chamber 15 to remove the deposits on the partition plate 14 and discharge through a discharge conduit Iñ. Preferably, the average upward velocity of the desulfurized gas in the upper space B is 0.5-5 m / s, more preferably 0.7-4 m / s, from the standpoint of economy and efficiency of the separation of the mist and Solid particles. The average upward velocity of the present is based on the horizontal sectional area of the upper space B that excludes the sectional areas of the tubes sprinklers 7 and similar structures that do not provide steps for the desulfurized gas. The average horizontal velocity of the desulfurized gas in the headspace B is preferably 8 m / s or less, more preferably 6 m / s or less for reasons of the formation of the liquid phase / stable mixed gas layer A. The horizontal velocity The average is based on the vertical sectional area of the upper space B in a space adjacent to the spray pipe 16. The velocity of the desulfurized gas flowing upward through the spray pipes 16 is preferably 6-20 m / s, more preferably of &-15 m / s for reasons of? effective separation of fog and solid particles and the economy. The desulfurized gas introduced into the third chamber 15 strikes against the upper wall thereof and is directed horizontally. In this way, the solid particles and the liquid entering are separated in the third chamber 15 by beating and by gravity. The average horizontal velocity of the desulfurized gas in the third chamber is preferably 10 m / s or less, more preferably & m / s or less for reasons of effective separation of those particles. The average horizontal velocity is based on the vertical sectional area of the third chamber in a horizontally separated location at a distance of 2 m from the exit port 9. Each of the sprinkler tubes 7 may have any desired section shape such as a circular shape, a polygonal shape (triangle, square or hexagonal) or a rectangular shape (conduits). The gas injection holes 8 formed in the lateral peripheral wall of each spray tube 7 can have any desired shape such as a circle, triangle, rectangle, hexagon, groove or star. If desired, the injection holes 8 can be placed in two or more arrangements, as shown in Figure 3. It is preferred that the equivalent internal diameter Dp of the spray tubes satisfy the following condition: 2D "? Dp 12DH, more preferably 3DM < Dp < 10D ", where Dw represents the equivalent diameter of the gas injection hole 8. Generally, the equivalent internal diameter Dp, is -300 mm, preferably 50-300 mm. The equivalent diameter DH of the injection hole 8 is generally 3-100 mm, preferably 5-50 mm. The equivalent diameters Dp, and Dw are co or defined below: wherein Sp represents the horizontal sectional area of the interior of the spray tube 7 at a location where the gas injection orifices 8 and Lp are provided, represents the internal peripheral length of the gas spray tube 7 at the same previous location, and Dw = 4SH / LM wherein SH represents the area of the gas injection port 8 and l_H represents the internal peripheral length of the gas injection port 8. The lower open end of each of the spray tubes 7 may be of any desired shape and may be, for example, horizontal, inclined, notched or wavy. The average axial distance Lß > , between the center (geometry centroid) of the gas injection port and the lower end of the spray tube 7 is preferably adjusted so that no waste gas passes through the lower open end of the spray tube or, in other words, that the liquid level of the absorption liquid L always exists in the spray tube 7. This can be achieved by adjusting the distance L "from 3S to 8S, more preferably 4S to 7S, where S represents a value obtained by dividing the dynamic pressure of the gas of waste injected through the gas injection orifice at a maximum velocity Vm > , between the density of the absorption liquid L. A preferred spray tube 7 is a plastic cylinder having an inner diameter of 25-300 mm and is provided with a plurality of equally spaced round holes having a diameter of 5-100 mm.

The spray tube 16 may have any desired section shape as circular, square or rectangular. It is important that each two adjacent gas injection orifices 8 of each of the spray tubes 7 be separated from each other by a distance such that, when each of the gas injection orifices 8 is considered as a circle having the same area that the area of the hole 8, the distance P between the centroids (center of gravity of the geometry) of the two adjacent gas injection orifices satisfies the following condition. 1.15 < P / D 6, preferably 1.2 < P / D < 5, where D is a diameter of one of the two circles that is smaller than the other. Figures 2 and 3 describe examples of the arrangement of gas injection orifices. When the P / D ratio is less than 1.15, the average desulfurization is considerably reduced since the waste gas flowing injected through separate injection ports is ready to be combined. Primarily, the jet flows from the adjacent injection ports interferes with another such that the liquid-gas phase layer A (foam phase layer) becomes unstable. A P / D ratio of less than 1.15 is also disadvantageous in the manufacture and maintenance of the spray tube 7. On the other hand, a too large P / D ratio in excess of 6 causes the reduction of the volume efficiency so that it is disadvantageously The use of a large device is necessary.

It is also important that the maximum velocity Vm H of the waste gas passing through each of the gas injection orifices 8 be controlled so that it satisfies the following conditions (l) - (4): (1) Y 4.55 preferably Y > 6.5S (2) and 24S, preferably Y < 22S (3) 0.05 < And < 1.0 (4) 0.005 í S < 0.06 where Y is the pressure of the waste gas required to carry out the desulfurization and S represents a value obtained by dividing the dynamic pressure of the waste gas injected through the gas injection orifice at the maximum velocity Vm-tx between the density of the absorption liquid. The pressure of the waste gas required for desulphurisation (pressure in terms of the column of the absorption liquid, unit: m) is defined by: Y = T + L " where T represents a value obtained by dividing the pressure loss (unit: kg / m1 *) waste gas passing through the gas injection hole 8 between the PIX density (unit: kg / m3) of the absorption liquid L and LIX that represents an average distance between the centroid of the hole of? injection of gas 8 and the liquid level of the absorption liquid in the state in which no gas is injected into the spray tube 7. In other words, the pressure Y is a value obtained by dividing the pressure (unit: kg / m1,2) required for the waste gas fed to the spray tube 7 to pass through the gas injection port 8 towards the upper space B by means of the PIX density (unit: kg / m3) of. absorption liquid L. Practically, the value T is on the scale between 2.5S and 4S (where S is as defined above) and depends on the form, the gas injection hole 8 and the average of? Waste gas flow. Since, in the present invention, L?: T / S is between 2 and 20, preferably between 4-18, as described so far, the pressure Y is expressed as follows: Y = T + LIX = (2.5 to 4) S + (2 to 20) S = (4.5 to 2) S The maximum speed mmw and the value S has the following relation: S = (dynamic pressure at the maximum speed Vm H) / (density Pxx of the absorption liquid) = < P? x Vm. "x Vm.?/2G)/PIX = Vm and x PX / 2GPIX n where P represents the density (kg / m3) of the waste gas, P:?; X represents the density (kg / m3) of the absorption liquid and G represents the gravitational acceleration (9.8 m / s). Figure 5 shows a relationship between the value 3 and the pressure Y at different scales of desulphurization Z. The term "desulphurization Z" scale used herein is defined as follows: Z = (1 - QolJt G.ir.> x 100 <$) where? Qait represents the flow scale of the sulfurous acid gas contained in the purified gas discharged through the outlet port 9 and Qln repiesenta the flow scale of the sulfurous acid gas contained in the g < 3s of waste introduced through the inlet port 6. As seen in figure 5, there is a minimum value in the pressure Y on a given desulphurization scale Z. It is preferred that the value S be selected so that S is minimum in the desired desulfurization scale. For example, when a Z desulphurization scale of 90% is intended, an S value of approximately 0.009 m is used. When a desulphurization scale Z of 70% is intended, the S value is preferably approximately 0.009 m When the desulphurization is carried out while the desired desulphurization scale is alternated between 99 3; and 70, the S value preferably set at 0.035 m which provides the minimum pressure Y at the desulphurisation scale of 99% 'and which satisfies the above conditions. l) - (4) to the desulfurization scale of 70. Once the S value is determined, the maximum velocity Vmj ,? it is determined in accordance with the formula described above: S = VmmHa x P? / 2GP ?? The number of the spray tubes 7 and the total area of the openings of the gas injection holes 8 in each of the spray tubes 7 are then determined based on the maximum velocity Vmm > < . The arrangement of the sprinkler tubes 7 connected to the partition plate 3 is not specifically limited insofar as the distance Lx between two adjacent sprinkler tubes satisfies the following condition: 1. 5 Lx / S 10.0, preferably 2 Lx / S 8, where S is as defined above. The distance Lx is the minimum distance from the outer periphery of a spray tube 7 to the outer periphery of the spray tube / is located closest to all. When the Lx / S ratio is less than 1.5, the desulfurization scale is considerably reduced since the jet flows from the two spray tubes 7 and interferes with each other so that the mixed liquid / gas phase layer A becomes unstable. On the other hand, a Lx / S ratio too large in excess of 10 causes the reduction in volume efficiency so that it is necessary to use a large apparatus. The distance Lx is generally 0.05-0.6 m, preferably 0.075-0.45 m, and is thus selected to meet the requirement of the previous Lx / S ratio. For reasons of an increased amount of the waste gas treated per unit area of the partition plate 3, it is preferred that the distance Lx be as small as possible. The value S is determined in accordance with the equation described above. In this regard, the maximum speed Vm < »" Is on the scale of 8-35 m / s, the density Px of the waste gas is 0.91-1.2 kg / m3, and the density PIX of the absorption liquid is 1,000-1,300 kg / m3. For reasons of the reduction of operating costs (desulfurization costs) of the desulfurization apparatus, it is desired that the S value be as small as possible, although from the point of view of construction costs, an S value too small is undesirable. To reduce the velocity of the waste gas passing through the gas injection orifices, mainly by increasing the equivalent diameter DH of the gas injection orifices or by increasing the number of? Gas injection holes, the S value can be made small. As previously described, the equivalent diameter Dw of the injection hole 8 is generally 3-100 mm. It is also important that the gas injection holes 8 of each of the spray tubes 7 are located so that the average distance Lxx between the liquid level W of the absorption liquid L in the state in which no gases are injected into the spray tube 7 and the center of each of the gas injection holes 8 satisfies the following condition : L, 20, pref erably 4 = Lxx / S < 18, more preferably 6 i Lxx / S i 16, where S is as defined above. When the ratio Lxx / S is less than two, the waste gas falls to have sufficient contact with the absorption liquid L so that the desulfurization efficiency is reduced. When the Lxx / S ratio exceeds 20, the bubbles in the waste gas combine and grow in size during the passage through the absorption liquid L so that the efficiency in the liquid-gas contact is reduced. The depth L x x is generally 0.05-0.9, preferably 0.075-0.75 m. When the S value is large or when the depth L?; T is large, the pressure Y of the waste gas is high and the desulfurization scale is increased. However, the operating costs depend on the pressure Y increasing as the pressure Y increases. When the ratio L? X / B is maintained on the scale described, it is possible to maintain the pressure Y of the waste gas supplied to the tubes sprinklers at a low level. In this way, it is possible to save the eneigia required for the desulphurisation and reduce the desulfurization costs. Adjusting the depth L? X so that it complies with the conditions described above 4.5S and 24S (Fig. 5) and 2 -. l_It / S. 20, the pressure Y required for desulfurization can be made small at any desired Z desulphurization scale. The curves shown in Fig. 5 are examples in which only the desired desulphurization scale Z is varied while remaining in others. parameters. such as the internal diameter of the spray tubes, the flow scale of waste gas through a spray tube, the pH of the absorption liquid and the concentration d & Sulfuric acid gas in the waste gas, constants. The shape and position of each curve varies with these parameters. As previously described, the value 3 should be 0.005 _ S _ 0.06. The appropriate S value, however, varies depending on the desired desulphurization scale Z, as seen in figure 5. With the desulphurisation apparatus being operated under vain operating conditions, it is advisable to set the S value to a high value of so that the desulfurization can be executed with ba or energy consumption. The LJX / S ratio is an important parameter to control the performance of the desulphurisation apparatus and provide an effective means to perform desulphurization at a desired Z desulfurization scale with minimal operating costs. " The depth Lxx can be changed by changing the liquid level Ul. By controlling the amount of absorption liquid L in the reactor or controlling the amount of the oxidation gas, such as air, fed through a line 12 to the absorption liquid reservoir L, the liquid level can be changed to provide an appropriate depth Lxx. In order to perform the desulfurization efficiently, it is necessary to agitate the absorption liquid L by means of one or more agitators 10. The agitator 10 can be composed of a rotary arrow 10 'extending vertically or obliquely inside the chamber and one or more sheets or propellers secured at the tip of the rotation arrow 10 'for rotation therewith. In this case, it is preferred that the liquid agitation of? The absorption is carried out with one or more agitators operated at a total driving power of 0.05-0.2 KW, more preferably 0.08-0.15 KW, per i3 of absorption liquid, for reasons of obtaining a particularly se desulphurization scale. Preferably, the stirring is executed so as to form a main recirculation flow (shown by the arrow R in Figure 1) in the agitated absorption liquid L. The main flow is accompanied by randomly occurring flows. In Figure 1, the reference numeral 11 designates an absorption agent feed line having an injection nozzle from which the absorption agent is injected into the main recirculation flow.

R. The absorption agent diffuses rapidly into the absorption liquid L and is rapidly supplied to the mixed phase layer of the liquid-gas A. If desired, the absorption agent can be fed through a plurality of conduits 11. The absorption agent can be supplied in the main recirculation flow R in an upstream or downstream position of the agitator blade 10. The injection nozzle of the absorption agent generally has a diameter of 20-100 mm, preferably 25-75 mm. Preferably, a plurality of nozzles are used to uniformly and rapidly disperse the? absorption within the absorption liquid L and to avoid the local increase of the pH and the deposition of scales on the ... walls of the sprinkler tubes. A nozzle is preferably used for 20-500 m3, more preferably 30-300 3, of the absorption liquid L. The absorption agent is injected in an amount of 0.5-20 kg mol / hour, preferably 1-10 kg mol / hour, by a mouthpiece. A portion of the absorption liquid L is discharged through a line 13 from the chamber 4 to maintain the calcium sulfate content in the absorption liquid L below a predetermined level. If desired, part of the discharged liquid can be treated for the removal of the calcium sulfate, mixed with the absorption agent and recirculated to the first chamber 4 through the line 11. The amount of the absorption agent incorporated within the Rc irculation absorption liquid is preferably such that the MG / A molar ratio of calcium sulfate (CaSO,., - 2Ha0) contained therein to the absorption agent is in the range of 0.1-20, preferably from 0-10, for reasons of preventing a local increase in pH in the region adjacent to the gas injection orifices 8. That is, the precipitation of fine crystals of calcium sulfate or fine crystals of CaCO3 is suppressed. Furthermore, even when such fine crystals are formed, they grow into large crystalline particles so that the clogging of the injection orifices. of gas 8 or the flaking of the walls of? the sprinkler tubes 7 can be avoided. If desired, a portion of the absorption liquid L can be recirculated to and distributed in the chamber 5 to cool and wash the waste gas introduced therein. The above-described oxidized gas supplied through line 12 is preferably injected into the main recirculation stream R at a downstream position of the stirrer sheet 10. In the mixed gas-liquid phase layer A, the following reaction occurs to fix the sulfurous acid gas contained in the waste gas as sulfate? calcium: SO »+ CaCOa + 1/20» + H »0 CaSO ^ -? Ha0 + Coa To improve the Z desulfurization scale, it is necessary that the previous reaction proceed efficiently in the layer of mixed phase of gas-liquid A. It is preferred that the oxidation gas is introduced into the absorption liquid L in an amount such that the molar ratio of the oxygen in the gas of? oxidation to the sulfurous acid gas in the waste gas is 0.5-6, more preferably 1-5. Figure 4 describes another embodiment of the desulfurization apparatus in which similar component parts have been designated by the same reference numerals. In this embodiment, the interior space of a housing member 2 is divided by a partition plate member 3 into a first lower chamber 4 and a second upper chamber 5. The first chamber 4 contains a reservoir of an absorption liquid L of so that a top space B is defined on the liquid level LS of the absorption liquid L. A waste gas to be treated is introduced through a gas inlet port 6 provided in the second chamber 5 and is injected within a reservoir of absorption liquid L through a plurality of spray tubes 7 secured to the partition plate 3 and a multiplicity of horizontally aligned gas injection holes 8 formed in a lower portion of each of the spray tubes 7 The desulfurized waste gas, by contact with the absorption liquid L, then flows into the upper space B above the liquid level LS. Preferably, the average upward velocity of the desulfurized gas in the upper space B is 0.5-5 m / s, more preferably 0.7-4 m / s, while the average horizontal velocity of the desulfurized gas in the upper space B is preferably 8 m / s or less, more preferably 6 m / s or less . During the flow of the desulfurized gas into the upper space B, a greater part of the mist and solid particles contained therein are separated from it by gravity and by collision with the sprinkler tubes 7. The desulfurized gas from which said solid particles and the liquid have been separated is discharged from the outlet port 9. The following example will illustrate the present invention.

EXAMPLE A waste gas containing 1,000 ppm sulfurous acid gas was treated in accordance with the process of the present invention under the following conditions: Reactor: 13 mx 13 mx 10 m (height) Maximum waste gas flow scale 1,000,000 m3 / hour Scale gas flow scale range 50-1003. (operated equally) Desulphurisation Scale Z: 903 »Density of waste gas Px: 1.1 kg / m3 Density of absorption liquid Pxx: 1,100 kg / m3 'Sprinkler pipe (cross section: circular) D imeter D ": 0.15 m Distance between adjacent sprinkler pipes L x: 0.15 Number: 1,390 Gas injection hole (circular) Diameter Dw: 0., 03 Number: 12 Distance between adjacent holes P: 0.0393 m Average distance LIX : 0.2 m Maximum Speed mm > < : 24.2 m / s S value: 0.03 Pressure Y: approximately 0.28 m It was found that the desulfurization treatment is carried out with minimal costs including installation and construction and operation costs. The invention can be modalized in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes that fall within the meaning and scope of equivalence. of the claims is therefore intended to be included therein.

Claims (10)

NOVELTY OF THE INVENTION CLAIMS 1. - A process for the desulfurization of a waste gas containing sulphurous acid gas, wherein said waste gas is blown into a reservoir of a stirred absorption liquid, contained in a reaction vessel and having a liquid level , through a plurality of gas sprinkler tubes each extending vertically downwards from a partition plate into said absorption liquid and each having a side peripheral wall provided with a multiplicity of gas injection orifices in a lower portion thereof, so that the waste gas is desulfurized by contact with the absorption liquid and the resulting desulfurized gas passes into an upper space defined between the partition plate and the liquid level of the absorption liquid, characterized in that? said gas injection orifices of each of the gas dispersion tubes are aligned substantially horizontally; wherein each two adjacent gas injection orifices of each of said gas dispersion tubes are separated from each other so that, when each of the two gas injection orifices is considered as a circle having the same area that the area thereof, the distance P between the centroids of said two adjacent gas injection orifices satisfies the following condition:

1. 15 < P / D í 6 wherein D is a diameter of one of said two circles that is smaller than the other; at the maximum speed Vmm > < of said waste gas passing through said gas injection orifices is controlled so that the following conditions are satisfied: And 4.5S and < 24S 0.05 < And 1.0 0.005 < S = 0.06 wherein Y represents a waste gas pressure required to carry out the desulfurization and S represents a value obtained by dividing the dynamic pressure of the waste gas injected through the gas injection orifice at the maximum speed m? > < between the density of the absorption liquid; wherein said gas dispersion pipes are positioned so that the distance Lx between the two closest dispersion pipes satisfies the following condition: where S is as defined above; and in that the gas injection orifices of each of the gas dispersion pipes are located so that the distance 8 average l-tx between the liquid level of said absorption liquid in the state in which no gases are indicated therein and the center of each of the gas injection orifices satisfy the following condition: 2 .. Lxx / S < twenty where 3 is as defined above.

2. A method according to claim 1, further characterized in that said scale S satisfies the following conditions: And 6.55 and 22S 0.05 and Y = 1.0 0.005 < S < 0.06 where Y and S are as defined above.

3. A method according to claim 1, further characterized in that the minimum distance Lx is on the scale of 0.05-0.6 m and the average distance Lxx is on the scale of 0.05-0.9 m.

4. A method according to claim 1, further characterized in that the amount of said absorption liquid in the reaction vessel is controlled such that the ratio Lx: t / S is in the scale of 2. to 20.

5. A method according to claim 1, further characterized in that air is blown into said absorption liquid in an amount such that the ratio LXI / S is in the range of 2 to 20. 6.- A The method according to claim 1, further characterized in that the agitation of the absorption liquid is carried out with one or more agitators operated at a total driving power of 0.05-0.2 KW per 1 m3 of said absorption liquid. 7. A method according to claim 1, further characterized in that the average upward velocity of desulphurized waste gas in the head space is 0.5-5 m / s and the average horizontal velocity of said desulfurized waste gas in the head space is 8 m / s or less. 8. A method according to claim 1, further characterized in that the gas dispersion pipes have an equivalent diameter of 25-300 mm and each of the gas injection orifices has an equivalent diameter of 3-100 mm. 9. A method according to claim 1, further characterized in that the waste gas desulfurized in the upper space is introduced through at least one spray tube into a chamber defined in an upper portion of the reaction vessel and is Discharged .? «From said reaction vessel through a discharge port provided in said chamber 10.- A procedure in accordance with the rei indication 9, further characterized in that the average horizontal velocity of the desulfurized gas in said chamber is 10 m / or less. PROCEDURE FOR THE DESULFURATION OF DISPOSAL GAS CONTAINING SULFUROUS ACID GAS. SUMMARY OF THE INVENTION A method for the desulfurization of a waste gas containing sulphurous acid gas by means of? the blowing of the waste gas to make contact within an absorption liquid through a plurality of spray tubes, wherein several operating conditions are controlled in a correlative and specific manner to perform the desulfurization in a stable manner at minimum costs . RM / cpm * cgt *