APPARATUS FOR TREATING SOLUTION OR SLURRY SOLUTION

Abstract: The present invention relates to an apparatus for treating a solution or a slurry solution and its improved types. This apparatus comprises a hollow rotating shaft (3) having a sealing mechanism (8') and a rotating mechanism at upper portions thereof, the apparatus being characterized by comprising a plurality of stirring branch pipes (1') attached to the lower end of the hollow rotating shaft vertically downward extending into the solution in a storage tank, and a plurality of gas jet pipes (7) disposed under the respective branch pipes, the gas jet pipes extending vertically downward and being opened at the lower ends thereof, whereby the shaft and the stirring branch pipes are rotated, while a gas is jetted from openings of the gas jet pipes through the sealing mechanism, the hollow rotating shaft and the branch pipes. The improved types of the above mentioned apparatus include an apparatus in which a plurality of stirring blades are additionally provided under the branch pipes, an apparatus in which a wash water feed pipe is additionally provided in the hollow rotating shaft, and the like.

Description: The present invention relates to an apparatus for treating a solution or a slurry solution according to the preamble of claim 1. Heretofore, as the apparatuses for oxidizing the produced sulfites in the wet exhaust gas desulfurizing installation, different systems have been employed. One system is known which comprises an air feed pipe having a number of jet holes disposed above the bottom of a storage tank for a solution to be treated, or in which a rotational stirring blade is additionally disposed above the lower portion of the pipe so as to accelerate a gas/solution contact, whereby the sulfites in the solution are oxidized; and another system (JP-U-61 150 047 and CH-A-587 785) in which a hollow rotational stirring blade having a number of gas jet holes is used to accelerate the jet of a gas and the formation of fine gas bubbles. In the former system, most of the gas is jetted through the jet holes in the form of relatively large gas bubbles and the formation of the fine gas bubbles by the rotational stirring blade is not expected, and thus when the fine gas bubbles are desired, it is necessary to provide a number of small gas jet holes. In particular, this technique has the drawback that the stirring effect of the stirring blade is lowered by the rise of the gas bubbles jetted through the gas jet holes so that solids are deposited on the bottom of the solution storage tank and the gas jet holes are locally clogged therewith, which fact leads to an increase in an original pressure for gas feed inconveniently. In the latter system (JP-U-61 150 047 and CH-A-587 785), the gas jetting means are provided in the stirring blade in order to simultaneously carry out a gas jet stirring and a mechanical stirring and to thereby uniformly disperse the gas into the solution to be treated. In the case of this system, the apparatus structure is simpler and a gas/solution contact efficiency is also higher than in the former system. In the solution storage tank in this apparatus, the solution to be treated is received, and a stirring branch pipe having a number of gas jet holes is attached to the lower end of a hollow rotating shaft . The branch pipe is adapted to be rotated by a rotating mechanism , and the gas can be jetted from the gas jet holes through the hollow rotating shaft and the stirring branch pipe . This treating apparatus can feed the gas to a gaseous phase section formed behind the stirring branch pipe and can tear off the gaseous phase section along the edge portion thereof in order to produce sufficiently fine gas bubbles. However, when this apparatus is applied to the treatment of a slurry solution, it is inevitable that splashes of the slurry solution get into the stirring branch pipe through the gas jet holes . As a result, scales appear in the stirring branch pipe and around the gas jet holes with the result that the gas jet holes are clogged therewith disadvantageously. Further, when the feed of the gas is stopped, the slurry solution tends to stream into the branch pipe , so that solid constituents precipitate therein, thereby producing the scales. Owing to such an occurrence of the scales, flow rates of the gas jetted through the respective branches will not be uniformed, and the branches will begin to vibrate and finally will not be able to rotate. In view of the above mentioned problems, the present invention has been achieved, and the object of the present invention is to provide a treating apparatus in which fine gas bubbles are jetted into a solution or a slurry solution in order to improve a gas/solution contact efficiency. Said object is accomplished by the features mentioned in the characterizing portion of claim 1. In the system of the present invention, it is intended that the gas jet portions are rotated in order to form fine uniform gas bubbles by the turning force and to thereby disperse them throughout in the solution or the slurry solution. In addition, this system has the function that the fine gas bubbles of the jetted gas are produced from a vigorous flow section or an eddy flow section produced behind each gas jet pipe by the rotation thereof, so that a gas/solution contact efficiency is heightened. That is, according to the present invention, the fine bubbles of the jetted gas can be formed and in consequence the gas/solution contact efficiency can be improved. The invention will now be explained based on the embodiments shown in the drawings. Figs. 1, 2 are schematic views showing embodiments of an apparatus for treating a solution or a slurry solution regarding the present invention; Figs. 3, 4(A) and 4(B) are sectional views illustrating a generation state of fine gas bubbles through gas jet pipes, Fig. 4(B) being a horizontal cross-sectional view of Fig. 4(A) The embodiment of the present invention will be described in reference to Fig. 1. In Fig. 1, a gas feed pipe 8 is connected to a rotating hollow shaft 3 with the interposition of a sealing mechanism 8', and a plurality of stirring branch pipes 1' are attached to the lower end of the rotating hollow shaft 3. Each of the branch pipes 1' is provided with a plurality of gas jet pipes 2 at the lower ends of which are opened. While a gas 11 fed through the gas feed pipe 8 is jetted from holes of the gas jet pipe 2 through the rotating hollow shaft 3 and the branch pipes 1', the rotating hollow shaft 3 is rotated by means of a rotating mechanism 9 in order to bring a solution or a slurry solution 10 in a storage tank 6 into contact with the jetted gas. As shown in Fig. 1, a length of each gas jet pipe 2 is greater than a jump height of solution splashes, and therefore the problem of the splashes can be solved effectively, too. However, when the solution or the slurry solution particularly containing solid constituents therein streams into the horizontal stirring branch pipes 1' at the stop of the operation, and when it is attempted to discharge the solution or the slurry solution in the pipes therefrom, such an attempt cannot be carried out successfully. Accordingly, it can be intended that each stirring branch pipe 1' in Fig. 1 is inclined by an angle of α to a horizontal plane as shown in Fig. 2. This constitution permits the solution or the slurry solution coming into the pipes to be discharged therefrom smoothly and perfectly at the resumption of the treating operation. Pigs. 3, 4(A) and 4(B) show the circumstances that when the gas jet pipe 2 is moved in the rotational direction indicated by an arrow, a gaseous phase section 16 is formed. Fig. 3 is concerned with an embodiment using the gas jet pipe 2 which is circular in its sectional view, and Figs. 4(A) and 4(B) are concerned with an embodiment using the gas jet pipe 2 in which its front surface and back surface in the moving direction are convexly curved and flat, respectively, as most easily understood in Fig. 4(B). When the gas jet pipe 2 shown in Fig. 4(B) is used, the gas 11 jetted from the opening of the pipe 2 is sucked into the gaseous phase section 16 which is formed behind a flat surface 2' of the pipe, and the gaseous phase section 16 is finely torn off along its edge portion 17 by an eddy force generated with the aid of the rotary motion of the pipe in order to form substantially uniform fine bubbles 18. This embodiment in Figs. 4(A) and 4(B) can more improve a gas contact efficiency than the gas jet pipe in Fig. 3 which is circular in the sectional view.

Claims: An apparatus for treating a solution or a slurry solution which comprises a hollow rotating shaft (3) having a sealing mechanism (8') and a rotating mechanism (9) at upper portions thereof, further comprising a plurality of stirring branch pipes (1') attached to the lower end of said hollow rotating shaft (3), whereby said shaft (3) and said stirring branch pipes (1') can be rotated, while a gas is jetted through openings of gas jet pipes (2) after passing through said sealing mechanism (8'), said hollow rotating shaft (3) and said branch pipes (1'), characterized in that a plurality of gas jet pipes (2) are disposed under said respective branch pipes (1'), said gas jet pipes (2) extending vertically downward from said respective branch pipes (1') and being opened at the lower ends thereof to provide gas jet openings and that the front surfaces of said gas jet pipes (2) are convexly curved in the direction of rotation while the back surfaces (2') are flat, respectively, in a horizontal cross-sectional view. An apparatus for treating a solution or a slurry solution according to claim 1 wherein said respective branch pipes (1') are inclined to a horizontal plane.

Inventors: ARAI, TOKUMA HIROSHIMA TECHNICAL INST., HINO, MASAO HIROSHIMA TECHNICAL INST., MAEDA, NOBUTAKA HIROSHIMA TECHNICAL INST., ONIZUKA, MASAKAZU HIROSHIMA TECHNICAL INST., TATANI, ATSUSHI HIROSHIMA TECHNICAL INST., YAMADA, KATSUHIKO HIROSHIMA TECHNICAL INST.
Applicants: MITSUBISHI JUKOGYO KABUSHIKI KAISHA
Application year: 1987
Main classification: B01F3
IPC codes: B01F7, B01F3