A kind of discarding paddle type full-sealed cement mixing and curing barrel and liquid injection mixing method

Abstract

The application discloses a kind of abandoned paddle type full-sealed cement mixing solidification barrels and liquid injection mixing methods, first mixing paddle, barrel cover cover body, mixing steel barrel are assembled and sent to charging station to carry out cover and cement filling;Then the mixing steel barrel is transported to the mixing station, so that the stirring power device, waste liquid injection device, call and exhaust device are connected with the stirring paddle driving connection end, waste liquid injection interface, call and exhaust device interface corresponding connection, start in the full-sealed environment to carry out the injection and stirring operation of radioactive waste liquid;After stirring, the mixing steel barrel is transferred to the temporary storage library maintenance.The application uses the mixing paddle discarded in the steel barrel, and the radioactive waste liquid and cement are solidified in the full-sealed environment, which avoids the secondary radioactive waste liquid generated by cleaning the mixing paddle and the problem of radioactive aerosol diffusion in the stirring process.

Description

Technical Field

[0001] This invention relates to the field of radioactive waste treatment technology, and in particular to a paddle-type fully sealed cement mixing and solidification tank and a liquid injection and mixing method. Background Technology

[0002] The paddle-discarding, fully sealed mixing tank cement curing process is a type of cement curing technology for radioactive waste liquid. Unlike other non-sealed tank cement curing processes, it employs a paddle-discarding and sealed mode, ensuring that the mixing and curing of cement mortar within the tank are always carried out under a completely sealed condition, preventing contamination of the production line and the curing tank. In the radioactive waste liquid cement curing process, mixing is essential for the uniform distribution of cement and radioactive waste liquid. However, the mixing process in the paddle-discarding, fully sealed mixing tank cement curing process is not yet mature, and problems such as uneven mixing, waste liquid overflowing from the curing tank, mixing device jamming, mixing paddle shaft breakage, and motor burnout still exist. The main reasons for this are: firstly, the sealing of the curing tank does not meet the requirements of the mixing process; and secondly, the mixing process methods and parameters are unreasonable. Summary of the Invention

[0003] The purpose of this invention is to provide a paddle-discarding, fully sealed cement mixing and curing tank and a liquid injection mixing method. It aims to solve problems such as radioactive waste leakage, mixing device jamming and breakage, and unsatisfactory cement curing properties caused by inadequate sealing of the curing tank and unreasonable parameter settings during the cement curing process in a paddle-discarding, fully sealed mixing tank.

[0004] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0005] This invention relates to a radioactive waste liquid cement solidification impeller-type mixing tank, comprising a steel tank, an impeller, a tank cover bolt, an impeller drive connection end, a ventilation device interface, a waste liquid injection interface, and a tank cover. The upper end of the impeller is the impeller drive connection end, which is integrally formed with the impeller. The impeller drive connection end passes through the lower end of the tank cover. The upper section of the impeller is rotatably connected to the tank cover, and the lower section of the impeller is located inside the mixing steel tank. The ventilation device interface and the waste liquid injection interface are both located on the tank cover. The edge of the tank cover is detachably connected to the upper end of the mixing steel tank via the tank cover bolt.

[0006] The solidification and mixing method of the radioactive waste liquid cement solidification impeller of the present invention includes the following steps:

[0007] S1: After assembling the mixing paddle, bucket lid, and mixing steel bucket, send them to the feeding station for lid removal and cement filling.

[0008] S2: The mixing steel drum is transported to the mixing station. After the mixing power unit, waste liquid injection device, ventilation device and mixing device are connected to the mixing paddle drive connection end, waste liquid injection interface and ventilation device interface respectively, the injection and mixing of radioactive waste liquid will begin in a fully sealed environment.

[0009] The injection and mixing of radioactive waste liquid in a fully sealed environment includes three steps: mixing dry cement ash, injecting the waste liquid into a steel drum and mixing, and uniform mixing.

[0010] The cement dry ash mixing is set with a mixing time of 3 to 5 minutes and a mixing speed of 60 to 70 revolutions per minute.

[0011] The waste liquid injection into the steel drum for stirring includes an initial stirring stage and a suspension stirring stage;

[0012] The initial stirring stage is a solid-liquid mixing stage, with the stirring paddle speed at 80-90 rpm;

[0013] The waste liquid injection volume and injection time are calculated using the following formula, and the initial stirring stage waste liquid injection volume and injection time are set according to the parameter range in the formula.

[0014] V=kW / ρ (1)

[0015] T0=kW / Q (2)

[0016] V represents the cumulative amount of waste liquid injected during the initial stirring stage;

[0017] T0 is the material injection time;

[0018] ρ is the density of the waste liquid;

[0019] Q represents the waste liquid injection flow rate, which should be kept stable at 3-4 cubic meters per hour.

[0020] W represents the total weight of pre-filled cement, calculated based on the water-cement ratio of the cement curing formula.

[0021] K is the control coefficient for the cumulative injection volume of waste liquid during the initial stirring stage, ranging from 17% to 22%.

[0022] The suspension and stirring stage is a solid-liquid suspension and mixing stage. The waste liquid injection flow rate is reduced to 70-80% of the initial stirring stage until all waste liquid is injected. The stirring paddle speed remains unchanged at 80-90 rpm.

[0023] The uniform mixing and stirring includes a thorough mixing stage, a vigorous stirring stage, and a stirring stage to improve uniformity;

[0024] Set the mixing time for 10 minutes and the mixing speed to 90-100 rpm during the thorough mixing stage.

[0025] The high-intensity mixing stage is set to a mixing time of 5 minutes and a mixing speed of 120 rpm.

[0026] To improve uniformity, set the mixing time to 2 minutes and the mixing speed to 90-100 rpm during the mixing stage.

[0027] S3: After mixing is completed, the mixing drum 6 is transferred to the temporary storage warehouse for curing.

[0028] The beneficial effects of this invention are:

[0029] This invention relates to a discarded paddle type fully sealed cement mixing and curing tank and a liquid injection mixing method. Compared with the prior art, this invention uses a discarded paddle in a steel tank, and the radioactive waste liquid and cement are cured in a fully sealed environment, avoiding the problem of secondary radioactive waste liquid generated by cleaning the paddle and the diffusion of radioactive aerosols during the mixing process. Attached Figure Description

[0030] Figure 1 This is a schematic cross-sectional view of the mixing and curing tank of the present invention;

[0031] Figure 2 This is a cross-sectional structural diagram of the mixing tank lid of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions herein are used to explain the present invention, but are not intended to limit the present invention.

[0033] like Figure 1 , 2 As shown: The radioactive waste liquid cement solidification impeller of the present invention includes a steel drum 6, an impeller 7, a lid bolt 1, an impeller drive connection end 2, a ventilation device interface 3, a waste liquid injection interface 4, and a lid 5. The upper end of the impeller 7 is the impeller drive connection end 2, which is integrally formed with the impeller 7. The impeller drive connection end 2 passes through the lower end of the lid 5. The upper section of the impeller 7 is rotatably connected to the lid 5 in a sealed manner. The lower section of the impeller 7 is located inside the impeller steel drum 6. The ventilation device interface 3 and the waste liquid injection interface 4 are both provided on the lid 5. The edge of the lid 5 is detachably connected to the upper end of the impeller steel drum 6 through the lid bolt 1.

[0034] This invention relates to a disposable, fully sealed cement mixing and solidification tank, which serves as both a packaging container for the solidification of radioactive waste and a disposable sealed mixing container. While meeting the requirements for the disposal of radioactive waste cement solidification waste packages in the EJ1042-2014 standard, the tank lid has been optimized for process adaptability to meet the process needs of mixing, injecting, and venting cement slurry within the tank under fully sealed conditions. The steel tank 6 features a double W-shaped ring rib design on its wall to enhance its mechanical strength and meet the mixing requirements. The mixing paddle 7 is fixed at the center of the steel tank 6, and the paddle drive connection end 2 extends from the lower end of the tank lid 5 through the mixing interface. The mixing interface is centered at the center of the tank lid 5, and the interface sealing assembly uses a wheel-type sealing design. Both the exhaust / venting device interface 3 and the waste liquid injection interface 4 employ spring-loaded self-sealing conical sealing joints and "O"-type sealing designs. The steel tank 6 and the tank lid 5 are connected by a flange sealed with 12 evenly distributed M16 tank lid bolts to prevent radioactive gas and waste liquid from overflowing from the interface or connection.

[0035] The solidification and mixing method for the radioactive waste liquid cement solidification impeller of the present invention is characterized by comprising the following steps:

[0036] S1: After assembling the mixing paddle 7, the lid 5, and the mixing steel drum 6, send them to the feeding station for lid removal and cement filling; send the steel drum pre-loaded with the mixing paddle to the cement feeding station for lid removal; according to the water-cement ratio in the cement formula, add dry cement ash to the steel drum containing the mixing paddle as needed, and then seal the lid.

[0037] S2: The mixing steel drum 6 is transported to the mixing station, and the mixing power unit, waste liquid injection device, and exhaust device are connected to the mixing paddle drive connection end 2, waste liquid injection interface 4, and exhaust device interface 3 respectively (the steel drum containing cement ash is moved to the mixing station along the guide rail by the motor, the mixing device lifting mechanism is started, so that the mixing interface, waste liquid interface, and exhaust interface are connected to the corresponding interfaces of the solidification drum respectively. After the connection is in place, the stop switch is triggered, and the descent stops). Then, the injection and mixing of radioactive waste liquid begins in a fully sealed environment.

[0038] The process of injecting radioactive waste liquid into the container under completely sealed conditions and mixing it includes three steps: mixing dry cement ash, injecting and mixing the waste liquid, and uniformly mixing.

[0039] The purpose of mixing the dry cement ash is to ensure that the cement ash inside the solidified steel drum is in a loose state, which is conducive to liquid injection and mixing. The mixing time is set to 3-5 minutes, and the mixing speed is 60-70 rpm. The purpose of setting these parameters is to ensure that the dry cement ash pre-filled in the steel drum is fully loosened, so that the dry cement ash and water can fully contact each other when the waste liquid is injected, and to prevent the cement from clumping and causing the motor to seize up.

[0040] The process of injecting waste liquid into the steel drum and stirring it is based on the requirements of the fully sealed tank stirring process. It involves continuously injecting waste liquid into the steel drum while stirring, including the initial stirring stage and the suspension stirring stage.

[0041] The initial stirring stage is a solid-liquid mixing stage. The key is to control the amount of waste liquid injected and the injection time. The stirring paddle speed is 80-90 rpm.

[0042] The waste liquid injection volume and injection time can be calculated using the following formula, and the initial stirring stage waste liquid injection volume and injection time should be set according to the parameter range in the formula.

[0043] V=kW / ρ (1)

[0044] T0=kW / Q (2)

[0045] V represents the cumulative amount of waste liquid injected during the initial stirring stage;

[0046] T0 is the material injection time;

[0047] ρ is the density of the waste liquid.

[0048] Q represents the waste liquid injection flow rate, which should be kept stable at 3-4 cubic meters per hour.

[0049] W represents the total weight of pre-filled cement, which can be calculated based on the water-cement ratio of the cement curing formula.

[0050] K is the control coefficient for the cumulative injection volume of waste liquid during the initial stirring stage, ranging from 17% to 22%.

[0051] The suspension and stirring stage is a solid-liquid suspension and mixing stage. To prevent excessive pressure inside the tank, the waste liquid injection flow rate in this stage is reduced to 70-80% of that in the initial stirring stage until all the waste liquid is injected. The stirring paddle speed remains unchanged at 80-90 rpm.

[0052] The purpose of controlling the waste liquid injection volume and injection time is as follows: In the initial mixing stage, the viscosity of the cement mortar in the tank is high and the torque output of the mixing device is large. Using a large flow rate of waste liquid injection can quickly reduce the viscosity of the cement mortar, which makes it easier for the waste liquid to mix fully with the dry cement mortar and also prevents the motor from burning out. If the waste liquid injection flow rate is too large or the injection time is too long, the fluid pressure in the tank will increase and damage the seal, causing the waste liquid to overflow.

[0053] The uniform mixing and stirring includes a thorough mixing stage, a vigorous stirring stage, and a stirring stage to improve uniformity;

[0054] During the thorough mixing stage, the mixing time is set to 8-10 minutes, and the mixing speed to 90-100 rpm. The purpose of these parameters is to ensure that after the waste liquid is injected, prolonged mixing allows the water and dry cement ash to be thoroughly mixed, forming a good cement slurry. At the same time, increasing the mixing speed prevents the cement slurry from clumping together near the mixing paddle in the steel drum, which would affect the quality of the solidified mixture.

[0055] The high-intensity mixing stage is set to a mixing time of 4-5 minutes and a mixing speed of 120 rpm. The purpose of these parameters is to ensure that the water and cement ash have been mixed sufficiently after the previous mixing stage. In order to avoid the presence of dry ash residue at the bottom and sides of the bucket, the mixing speed is further increased to mix all the waste liquid with the cement ash and achieve the water-cement ratio in the cement formula.

[0056] To improve uniformity, the mixing stage is set with a mixing time of 2-3 minutes and a mixing speed of 90-100 rpm. This stage is the final stage of mixing, and the purpose of these parameter settings is to ensure the uniformity of the cement slurry formed after mixing the waste liquid and cement, so that the final cement solidified body meets the requirements.

[0057] S3: After mixing is completed, the mixing drum 6 is transferred to the temporary storage warehouse for curing.

[0058] Example 1

[0059] Based on a water-cement ratio of 0.45, and a 400L steel drum with a paddle, 440kg of cement and 198L of waste liquid need to be pre-filled.

[0060] 1. The steel drum pre-loaded with a mixing paddle is delivered to the cement feeding station for cap removal; 440kg of cement is added, and the drum cap is then sealed.

[0061] 2. Move the steel drum containing cement to the mixing station along the guide rail using a motor, start the lifting mechanism of the mixing device, so that the mixing interface, waste liquid interface, and exhaust interface are connected to the corresponding interfaces of the solidification drum. After the connection is in place, trigger the stop switch to stop the descent.

[0062] 3. Perform dry ash mixing operation, set the mixing time to 5 minutes, and the mixing speed to 70 rpm.

[0063] 4. Perform the operation of injecting waste liquid into the steel drum and stirring.

[0064] During the initial mixing stage, the mixing speed is 80 rpm, the radioactive waste liquid injection flow rate is 4 cubic meters per hour, the cumulative injection volume of radioactive waste liquid is controlled at 22% of the total weight of the pre-added cement, i.e., about 96L, and the mixing time is 86 seconds.

[0065] During the suspension and agitation stage, the agitation speed is 80 revolutions per minute, and the injection flow rate of the radioactive waste liquid is controlled at 3 cubic meters per hour until the injection of the radioactive waste liquid is completed.

[0066] 5. Perform a thorough mixing and stirring operation.

[0067] Set the mixing time for the thorough mixing stage to 10 minutes and the mixing speed to 100 rpm.

[0068] The high-intensity mixing stage is set to a mixing time of 5 minutes and a mixing speed of 120 rpm.

[0069] To improve uniformity, set the mixing time to 2 minutes and the mixing speed to 100 rpm during the mixing stage.

[0070] 6. The steel drums containing cement mortar are sent to a temporary storage warehouse for curing.

[0071] Example 2

[0072] Based on a water-cement ratio of 0.5, a 400L steel drum with a paddle needs to be pre-filled with 413kg of cement and 207L of waste liquid.

[0073] 1. The steel drum pre-loaded with a mixing paddle is delivered to the cement feeding station for cap removal; 413 kg of cement is added, and the drum cap is then sealed.

[0074] 2. Move the steel drum containing cement to the mixing station along the guide rail using a motor, start the lifting mechanism of the mixing device, so that the mixing interface, waste liquid interface, and exhaust interface are connected to the corresponding interfaces of the solidification drum. After the connection is in place, trigger the stop switch to stop the descent.

[0075] 3. Perform dry ash mixing operation, set the mixing time to 3 minutes, and the mixing speed to 60 rpm.

[0076] 4. Perform the operation of injecting waste liquid into the steel drum and stirring.

[0077] During the initial mixing stage, the mixing speed is 90 rpm, the radioactive waste liquid injection flow rate is 3 cubic meters per hour, the cumulative injection volume of radioactive waste liquid is controlled at 17% of the total weight of the pre-added cement, i.e., about 70L, and the mixing time is 84 seconds.

[0078] During the suspension and agitation stage, the agitation speed is 90 rpm, and the injection flow rate of the radioactive waste liquid is controlled at 2.5 cubic meters per hour until the injection of the radioactive waste liquid is completed.

[0079] 5. Perform a thorough mixing and stirring operation.

[0080] Set the mixing time for the thorough mixing stage to 10 minutes and the mixing speed to 90 rpm.

[0081] The high-intensity mixing stage is set to a mixing time of 5 minutes and a mixing speed of 120 rpm.

[0082] To improve uniformity, set the mixing time to 2 minutes and the mixing speed to 90 rpm during the mixing stage.

[0083] 6. The steel drums containing cement mortar are sent to a temporary storage warehouse for curing.

[0084] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A liquid injection and mixing method for a paddle-type fully sealed cement mixing and curing tank, characterized in that, Includes the following steps: S1: After assembling the mixing paddle (7), the lid (5), and the mixing steel drum (6), send them to the feeding station for lid removal and cement filling; S2: Transport the mixing steel drum (6) to the mixing station, and connect the mixing power unit, waste liquid injection device, exhaust device to the mixing paddle drive connection end (2), waste liquid injection interface (4), and exhaust device interface (3) in a corresponding manner, and start the injection and mixing of radioactive waste liquid in a fully sealed environment. S3: After mixing is completed, the mixing steel drum (6) is transferred to the temporary storage warehouse for curing; The radioactive waste liquid injection and mixing operation in the fully sealed environment in step S2 includes three steps: cement dry ash mixing, waste liquid injection into steel drum mixing, and uniform mixing. The cement dry ash mixing is set to a mixing time of 3-5 minutes and a mixing speed of 60-70 rpm. The waste liquid injection into the steel drum for stirring includes an initial stirring stage and a suspension stirring stage; The initial stirring stage is a solid-liquid mixing stage, with the stirring paddle speed at 80~90 rpm; The waste liquid injection volume and injection time are calculated using the following formula, and the initial stirring stage waste liquid injection volume and injection time are set according to the parameter range in the formula. V=kW / ρ (1) T0 = ​​kW / Q (2) V represents the cumulative amount of waste liquid injected during the initial stirring stage; T0 is the material injection time; ρ is the density of the waste liquid; Q represents the waste liquid injection flow rate, which should be kept stable at 3-4 cubic meters per hour. W represents the total weight of pre-filled cement, calculated based on the water-cement ratio of the cement curing formula. K is the control coefficient for the cumulative injection volume of waste liquid during the initial stirring stage, ranging from 17% to 22%; The suspension and stirring stage is a solid-liquid suspension and mixing stage. The waste liquid injection flow rate is reduced to 70-80% of the initial stirring stage until all waste liquid is injected. The stirring paddle speed remains unchanged at 80-90 rpm. The uniform mixing and stirring includes a thorough mixing stage, a vigorous stirring stage, and a stirring stage to improve uniformity; Set the mixing time for the thorough mixing stage to 8-10 minutes and the mixing speed to 90-100 rpm; For the high-intensity mixing stage, set the mixing time to 4-5 minutes and the mixing speed to 120 rpm. To improve uniformity, set the mixing time to 2-3 minutes and the mixing speed to 90-100 rpm during the mixing stage.

2. The liquid injection and mixing method of the paddle-type fully sealed cement mixing and curing tank according to claim 1, characterized in that: The invention includes a fully sealed cement mixing and curing tank with a discarded paddle, comprising a steel drum (6), a mixing paddle (7), a lid bolt (1), a mixing paddle drive connection end (2), a ventilation device interface (3), a waste liquid injection interface (4), and a lid body (5). The upper end of the mixing paddle (7) is the mixing paddle drive connection end (2), which is integrally formed with the mixing paddle (7). The mixing paddle drive connection end (2) passes through the lower end of the lid body (5). The upper section of the mixing paddle (7) is sealed and rotatably connected to the lid body (5). The lower section of the mixing paddle (7) is located inside the mixing steel drum (6). The ventilation device interface (3) and the waste liquid injection interface (4) are both located on the lid body (5). The edge of the lid body (5) is detachably connected to the upper end of the mixing steel drum (6) through the lid bolt (1).

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