JPS5945405B2 - Suspended axial propeller stirrer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an underwater sedimentation storage tank for powdered and granular ion exchange resins, cellulose filter media, etc. used as radioactivity absorbers, and the deposited solids thereof are taken out of the storage tank as a solid mixed liquid. As a pre-treatment step, wave speed is applied to the supernatant mother liquor existing on the sedimentary layer of settled solids, and stirring and mixing is carried out while crushing and scattering the sedimentary sedimentary layer. A guide rail for the stirrer equipped with a sliding aid is installed separately between the insertion/removal hole for the stirrer drilled in the ceiling of the storage tank and the bottom of the tank, and the stirrer is suspended with a hoist. The waste generated in nuclear energy facilities is configured such that the supernatant mother liquor layer above the sediment layer is stopped at an appropriate position corresponding to the epithelial layer of the sediment layer, stirred, and gradually lowered to reach the bottom of the tank. This invention relates to an in-tank suspended type submersible electric axial flow propeller stirrer for use in a storage tank for radioactive absorbing materials, and its related auxiliary equipment.

These absorbing materials are transferred to the next treatment process after a long period of time, but the amount accumulated during that time is enormous, and there are also restrictions that it must be stored within a limited facility area within a radiation controlled area. On top of that, there are many extremely deep tanks placed close together. In the process of removing absorbent material from these deep storage tanks, when the absorbent material is hydraulically transferred as a solid mixed liquid, the settled absorbent material forms a layered structure, and it is extremely difficult to remove the absorbent material unless it is suspended in the mother liquor. Therefore, an in-tank agitator is used to transfer the slurry with a slurry pump while measuring floating mixing with the mother liquor.However, the mechanical methods of conventional in-tank agitators include one-way rotation, forward and reverse rotation, and reciprocating. There were many types of mechanisms, such as a moving system, a swinging system, or a combination of these mechanisms.
Most of the main stirring components, such as rotating rods, rotary blades, and rotary impellers, are installed at the end of the shaft or have overhanging blades installed on the shaft, depending on the area to be stirred in the tank. If the overhung type was not suitable, a bearing was installed between the drive and the shaft end or between the shafts. However, its use was limited to certain areas within the tank. In addition, the main body of the stirrer may be a highly functional one with a special mechanism, such as a variable pitch type or a complex and large type with a movable conversion type that can be used depending on the area where it is used. is permanently installed, and in order to handle the work inside the tank under the harsh conditions of processing radioactive contaminants, the entire agitator based on the mechanism, the main agitating component, the shaft,
The construction of bearings, shaft seals, their maintenance, auxiliary equipment, and other necessary equipment must be large and heavy, which may pose an unreasonable impact on the safety and strength of the tank in which they are installed. It has the disadvantage of forcing specific specifications, and there is also a limit to its applicability to overhang type bearings.In other words, even if a long shaft type bearing is installed with many bearings, it cannot be adapted to cases where there is a large amount of solid accumulation in the tank. The following problems arose. Depth of storage tank, horizontal cross-sectional shape, vertical cross-sectional shape, handling liquid quality and agitator installation location, burying of mechanism parts in sediments, infiltration, failure of mechanism operation due to solid intrusion, influence of precipitated solid binding mass, etc. There are correlations such as the position of the stirrer with respect to the boundary between the clear mother liquid layer and the sediment layer.
There is a limit to the area within the tank where agitation can be effectively carried out to overcome these conditions and achieve the desired floating mixture, and for this type of storage tank in particular, for the reasons mentioned above, the area within the tank is limited compared to its cross-sectional area. Usually, the storage tanks are as deep as 20 meters, and in the case of a multi-tank system in which they are placed close together, each storage tank must be equipped with an agitator in advance, and after installation, it is necessary to
It is a property that is left unattended for a long period of time, ranging from 20 to 15 years.
Even if intermittent operation is performed at irregular times, the actual operation will be in the distant future, so there are many questions about whether it will work perfectly at that point, and how reliable the function will be if it continues to be contaminated. The cause of the inconvenience lies in the fact that the agitator is permanently installed in advance. Therefore, the present invention uses a vertical shaft submersible motor, positions the output shaft direction downward, connects the agitator directly to the mounting flange, and equips the soil frame on the side opposite to the output of the submersible motor with eye bolts for suspension. is not fixed, but a hole is drilled in the ceiling for inserting and extracting the agitator, and it is always hoisted outside the tank.
When necessary for the intended work, it is suspended in a tank, and the supernatant mother liquor on the top of the sediment layer is circulated, and the flow of the mother liquid is used to sequentially crush and scatter the epithelial layer of the sediment layer while stirring and mixing with the mother liquor. Floating solids and rotating in the normal direction as they progress.
The system attempts to uniformly stir and suspend the solids in the storage tank by turning the tank upside down and gradually dropping it down toward the bottom of the tank along a pre-prepared guide rail. If the ratio to the amount is large and it is impossible to stir and mix to a concentration that can be transferred with a slurry pump, first pump the small mixed portion of the soil clear mother liquor as a result of stirring,
In this case, the stirrer is lowered by the amount of layer loss from the sediment layer, and at the same time, appropriate injection is made, and the above procedure is repeated, and this effective stirring is repeated until the bottom of the storage tank is reached. However, when operation is no longer required for a long period of time, it can be appropriately removed from the tank, and each part is appropriately configured to facilitate the execution of these steps. Hereinafter, the present invention will be illustrated and explained using specific embodiments. FIG. 1 is a cross-sectional view of the internal state of the tank when the present agitator is in use, showing the general outline of the present invention. In this drawing, A is a sediment storage tank, and a hole C for insertion and removal of the present agitator B is provided in the ceiling of the tank. D is an earth rolling machine that is movably placed above the center of the insertion/removal hole to suspend the agitator. E is a guide rail with an agitator attached that contributes to stable lifting and prevention of lateral vibration during stirring operation, and extends over the entire vertical length of the tank. F is a guide rail support that bridges this rail to the tank wall. Reference numeral K denotes a winding machine for the power cable, which operates in conjunction with the winding machine D of the agitator to wind and unwind the power cable L. Next, FIG. 2 and subsequent figures will be explained. FIG. 2 shows a vertical cross section of the tank, and shows the state before the insertion of the stirrer after the radioactive absorbing material has been stored for a long period of time. As already mentioned, the ceiling G has a hole C for inserting and removing the stirrer, which has a radiation shielding lid H that is used during long-term storage and after inserting and removing the stirrer. Guide rails E for raising and lowering the agitator are fixed vertically throughout the entire length up to the bottom of the tank, and they are designed to withstand the depth of the storage tank, the horizontal load from the agitator, and the rotational reaction force. It should have sufficient stress and also be rigid enough to allow the stirrer to move up and down. I is the supernatant layer of the mother liquor, J
1 is a deposited layer of radioactivity absorbing material, A is a sedimentation tank, which is extremely deep in this figure, and D is a hoisting machine of a known type that can meet this purpose. FIG. 3 is a perspective view of an example of a guide rail E for raising and lowering the agitator, which has a circular cross section. 2 and 3 are mounting plates that connect the rail to the bottom of the tank and the insertion/removal hole.

Each is fixed with foundation bolts or welding. Reference numeral 4 denotes a portion where the upper end of the rail is curved outward, which facilitates attachment to each rail when inserting the agitator.

The guide rail has a smooth surface and is made of a material such as stainless steel that is durable enough to be permanently placed in the tank. 5 is a reinforcing material, which is a ring part for buckling resistance of the rail and maintaining the rail spacing, and also serves as a bridge between the support F and the tank wall.

Each of the rails constructed in this way can be installed in a parallel and vertical manner as shown in this figure, or be threaded in a multi-threaded manner, extending from the upper part to the lower part, so that the agitator can move up and down accurately. In either case, it has sufficient strength to withstand the shaking force and rotational reaction force of the agitator, and is combined with the combined force of these and the weight of the rail itself. The body should be rigid enough to withstand buckling force. Fourth
The figure is a partial sectional view of the present stirrer. 6 is an axial flow propeller type stirring blade, which is attached to the shaft 8 end of the submersible electric motor 7.
It is a dual-rotation type that supports forward and reverse rotation, and has a compound blade type with two or more blades, and the number of blades is not limited.

Reference numeral 9 denotes an outer body for rectifying the flow, and its upper and lower ends are bell mouth openings, which are formed with a curvature to diffuse the liquid in the forward and reverse flows in the desired direction.

Reference numeral 10 denotes a morning glory-shaped rectifying guide curved plate disposed on the back of the stirring blade, and rectifying plates 11 are fixedly arranged radially and at equal intervals, so that the outer body is fixed through the rectifying plate. To support.

The underwater electric motor 7 is of a vertical flange type and is capable of forward and reverse rotation, and is equipped with a thrust bearing having sufficient durability to hold both thrust loads at that time. The rectifying guide curved plate 10 is connected to the lower end of the outer frame of the electric motor at a flange portion 12. 13
is an infiltration protection frame body, which is fixed to the lower opening end of the outer shell 9, and is designed to prevent the lower opening from coming too close to the deposited layer, and to prevent the lower opening from coming too close to the deposited epithelial layer surface to the lower opening. It should be long enough to ensure the minimum height, yet strong enough to support the entire weight, and also serve to prevent the opening from being blocked by large solid pieces of crushed material.

Reference numeral 14 denotes a sliding aid for lifting, which is attached to the outer surface of the outer shell 9, the outer diameter of which is larger than the outer diameter of the protective frame, the submersible motor, and the outer frame of the motor. It protrudes toward the side and slides along the guide rail surrounding the stirrer, etc.

FIGS. 5 to 12 illustrate the contact relationship between the sliding aid and the guide rail. Figures 5 and 6 show the case where an hourglass-shaped carriage 16 is used as a sliding aid for a guide rail having a circular cross section. FIG. 7 and FIG. 8 are examples of a case where a ring-shaped wheel 18 is brought into contact with a guide rail 17 having a concave cross section.
FIGS. 9 and 10 show a guide rail 19 having a circular or shaped steel back-shaped cross section and a tank 20 having a concave cross section fitted therein. 11 and 12 show a case in which an IilA 22 having a circular cross section is brought into sliding contact with a guide rail 21 having a concave cross section. The contact surfaces are in a fitting shape and therefore have sufficient rigidity to support the rocking and rotational reaction forces generated during operation of the stirrer, yet are susceptible to sliding. In the case of wheel-shaped ones, four or more of them are arranged, and in the case of tank-shaped ones, two or more of them are arranged in a balanced manner under the ground. Since the stirrer of the present invention is constructed as described above, it has the safety, earthquake resistance, complete operation after long-term storage, and resistance required when taking out contaminated waste from the storage tank as equipment accompanying nuclear power utilization equipment. Radiation structure, effective use of storage tanks with limited capacity to store as much as possible, countermeasures against sinking of stirring equipment, maintenance management during non-operation, cleaning, disassembly, assembly, and repair associated with inspection and maintenance. The equipment's tank size is small, lightweight, high-performance, and has a suspension type that can be used at any time. It has many benefits in reducing its own strength and improving earthquake resistance, and eliminates the need to install an agitator in each tank in advance for multi-tank equipment, and can be installed only in the tank for the intended work each time. It is possible to operate the tank by suspending it, and this eliminates the above-mentioned waste in permanently installing all the tanks, which is economically huge.Also, if it is installed permanently, the storage capacity of the tank will not be reduced by occupying the tank. Compared to the whole, only a very small number of permanent guide rails are required, and since they are not permanently installed, the radiation irradiation period is only a short period during which the suspension hangs down, so there is almost no risk of material deterioration due to contamination and operation. It will not cause incapacity. Furthermore, sufficient inspection and repair work can be carried out by taking the tank out of the tank easily and reliably, and by simply adjusting the length of the suspension rope and power cable during use, the cable can be hung at the desired location depending on the amount of deposited layer inside the tank. The effects of the present invention, which can be stopped, moved up and down easily, and stirred throughout the tank, will become an indispensable device for those involved in the use of nuclear energy.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the operating state of the agitator, Fig. 2 is a longitudinal cross-sectional view of the storage tank, and Fig. 3 is a perspective view of the installed guide rail.
FIG. 4 is a partial cross-sectional view of the agitator, and FIGS. 5 to 12 are a side view and a perspective view of the embodiment showing how the sliding aid and the guide rail are connected, respectively. Explanation of the symbols attached to the drawings, A...Sedimentation storage tank,
1... Guide rail, B... Stirrer, 2.
...Mounting plate, C...Insertion/removal hole, 3...
... Mounting plate, } ... Winding machine, 4 ... Upper curved surface, E ... Guide rail, 5 ... Reinforcement material, F ... ... Support, 6... Stirring blade,
G...Ceiling section, 7...Underwater electric motor, H
...shielding lid, 8...motor shaft, l...
...Mother liquid supernatant layer, 9...Guiding outer shell, J...
... Deposition layer, 10 ... Guide cylinder (guide curved plate), K ... Cable winder, 11 ...
... Rectifier plate, L ... Power cable, 12 ...
...Flange part, M ... Tank bottom, 13 ...
...Protective frame body, 14...Sliding aid, 15...
...Circular cross-section rail, 16...Drum-shaped wheel, 17
...Concave guide rail, 18...Circular wheel, 19...Circular or rectangular cross-section guide rail, 20
... Concave cross section rod, 21 ... Concave cross section rail, 22 ... Circular cross section rod.

Claims (1)

[Claims] 1. In a suspension-type submersible electric axial flow propeller stirrer for use in a submerged sedimentation storage tank for radioactivity absorbing material that has adsorbed radioactivity in nuclear power utilization facilities, Both openings are formed into bell mouths and fixed to the morning glory-shaped guide curved plate through a rectifying plate, which is attached to the flange part of a vertical submersible motor, and has multiple stirring blades fixed to the shaft end of the submersible motor. An axial propeller is installed at the bottom of the morning glory-shaped guide curved plate, and the submersible electric motor, the cylindrical guide outer shell, and the protective frame provided around the lower opening thereof are protruded further than the outside diameter of the propeller, and the axial propeller moves up and down. An auxiliary tool is installed in the cylindrical guide outer shell and the outer frame of the submersible motor, and is inscribed in the guide rail that reaches from the side of the upper agitator insertion/removal hole to the bottom of the tank, and is installed at the upper part of the non-load side of the motor. A hanging support type axial flow propeller agitator characterized in that the agitator is suspended from a hanging support and the agitator moves up and down along the rail.