RU2374706C1 - Device for cementing liquid radioactive wastes - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: device consists of container installed on transportation trolley with lifting platform, process cover of container, mixing device made in the form of support frame with the mixer fixed therein, supply points of liquid radioactive wastes and cement, container elevator, connection elements between points, and device operation control panel. Top of support frame is equipped with metal ring with outer diametre which is not more than inner container diametre. Supply point of liquid radioactive wastes is made in the form of dosing capacity provided with pressure gauge, sensors of lower, upper and current levels, receiving connection pipes of wastes, compressed air and process water, outlet connection pipes of wastes, emergency discharges and process gases; at that, outlet connection pipe of wastes from the dosing device is connected by pipeline to process container cover. Cement supply point is made in the form of the capacity equipped from above with a loading box, and from below - with rotor feeder which is then in series connected to screw feeder and process cover of container. Transportation trolley with lifting platform moves along rails.

EFFECT: invention improves device operating reliability when cementing wastes with various salt content and in emergency situations.

8 cl, 1 dwg

Description

The invention relates to the field of solidification of liquid radioactive waste by cementing it.

A device for cementing liquid radioactive waste is known, comprising a container and a measuring device equipped with mixers and level gauges, a container with a mixer installed in it, a cement supply unit with additives, an external gas pressure source connected to the container and a measuring device, discharge pipes, one of which connects the container with a dipstick, the second is installed with the possibility of connecting the dipstick to the container, the unloading tubes are equipped with expanders, and the tank is equipped with a nozzle for supplying liquid radioactive waste (RU 2309472 C1, 10.27.2007).

The disadvantages of this installation are:

- the need to dose liquid radioactive waste twice - in the tank and meter with accurate calculations of the necessary gas pressure for pumping, which increases the likelihood of a poor-quality final compound;

- the presence of two external gas sources, which increases the accident rate during operation of the installation.

A known installation for cementing liquid radioactive waste, containing a protective chamber equipped with a lock compartment, a container, a container for dry cement with additives and a cement compound preparation unit located in the protective chamber, a container for liquid radioactive waste with a device for supplying liquid radioactive waste to a container and a mixing device, connected to the drive of rotation and reciprocating "up and down", while on the floor the airlock compartment and the container are mounted on rails with It is possible to enter the protective chamber through the airlock compartment, the unit is also equipped with a cement paste preparation unit located outside the protective chamber, while the cement compound preparation unit is located above the container stopping point in the protective chamber with the possibility of interaction with the container, and the cement paste preparation unit is located above the stopping point container outside the protective chamber with the possibility of interaction with the container (RU 54691 U1, 07/10/2006).

The disadvantages of this installation are:

- the lack of a cleaning system for the preparation of the cement compound from contaminants of the cement mortar and decontamination system, which increases the unreliability of the installation;

- the inability to obtain a cement compound with a high content of liquid radioactive waste (LRW), which reduces the efficiency of the cementing process at the installation.

A known installation for cementing waste by impregnating waste with cement mortar, which contains a sealed working box. A radioactive waste container with a lid, a vibrating platform for placing the container mounted on a trolley with a drive, a liquid dispensing tank equipped with a level gauge and solenoid valves at the inlet and outlet of the liquid dispensing tank, a mixer containing a liquid nozzle, a cement loading nozzle and a drain nozzle with valve. The installation also contains a cement mortar supply system to the container, a control unit located outside the box, a ventilation system and a decontamination system equipped with a nozzle (RU 2301468 C1, 06/20/2007).

A disadvantage of the known installation is the need for periodic cleaning of the mixer after impregnation from the remaining cement mortar, which complicates the operation of the installation.

The closest in technical essence and the achieved result is a device for the curing of liquid radioactive waste, containing a container with a stirrer and a technological lid mounted on a trolley, a container lift, nodes for supplying liquid radioactive waste and cement, communication elements between the nodes, a level switch with lower and the upper levels in the container, working on changing the electrical conductivity of the media air - liquid radioactive waste and air - cement compound, and the design of the sensors the level represents segments of a two-wire cable, the lengths of which correspond to the volumes of liquid radioactive waste and cement compound, depending on the salt content of liquid radioactive waste (RU 2218618 C1, 08.20.2003).

However, the installation adopted for the prototype has the following disadvantages. The presence in the container of contact sensors of the lower and upper levels, the possibility of their damage when mixing the cement mortar, and the lack of control over the rotation of the mixer reduces the reliability of the installation. It is necessary to periodically stop work to clean the clutch assembly from contamination with cement mortar. The installation is not suitable for the continuous curing of wastes having different salinity and viscosity, and is not equipped with the devices necessary in case of emergency situations.

The objective of the present invention is to increase the reliability of the installation and the provision of cement compounds, regardless of the salinity and viscosity of the liquid radioactive waste entering cementing.

The problem is solved by the described installation for cementing liquid radioactive waste, which contains a container mounted on a transport trolley with a lifting platform and equipped with a mixing device, a container lift, a technological cover of the container, nodes for supplying liquid radioactive waste and cement connected to the technological cover, sensors and elements communication between the nodes, while the mixing device is made in the form of a support frame with a mixer fixed on it, and the support frame is sn abzhena in the upper part with a metal ring made with the possibility of docking the container with the technological cover, the node for supplying liquid radioactive waste is made in the form of a dosing tank equipped with a manometer, sensors of the lower, upper and current levels, nozzles for receiving waste, compressed air and process water, outlet pipes waste, emergency discharges and process gases, while the outlet pipe of the waste from the metering device is connected by a pipeline to the technological cover of the container, the feed unit ment is designed as a vessel equipped with a top-loading box, and the bottom rotary feeder, connected in series with the screw feeder and the process container cover.

Preferably, the waste receptacle in the metering container is installed so that waste can be fed to the bottom of said container.

The supporting frame of the mixing device is made in the form of a welded frame.

Mostly, the cement supply unit is equipped with load cells, a load-lifting mechanism and is connected to a cement dust cleaning system.

The node supplying liquid radioactive waste on the nozzles of the dosing tank contains valves with an electric actuator.

Preferably, the container process lid is equipped with a non-contact sensor for monitoring the level of the contents of the container, a sensor for controlling the rotation of the mixer, a sensor for the upper position of the container, and a nozzle for blowing off the process gases associated with the ventilation system.

The transport trolley with a lifting platform is equipped with load cells.

The transport trolley is made with the possibility of its movement along rail tracks, which are equipped with sensors for monitoring the position of the trolley and a sensor for lower monitoring the position of the container.

The drawing shows a diagram of the claimed installation. The installation contains: 1 - a container, 2 - a transport trolley, 3 - rail tracks, 4 - a hoist, 5 - a lifting platform, 6 - a mixing device, 7 - a support frame, 8 - a mixer, 9 - a metal ring, 10 - a technological cover, 11 - nozzle for supplying liquid radioactive waste, 12 - nozzle for blowing off technological gases, 13 - sensor for controlling the rotation of the mixer, 14 - shaft of the electric drive of the mixer, 15 - electric drive of the mixer, 16 - sensor for level control non-contact, 17 - pipe for supplying cement, 18 - load cell , 19 - cement dispenser, 20 - loading box, 21 - connection pipe with cement dust air purification system, 22 - load-lifting mechanism, 23 - screw feeder electric drive, 24 - rotary feeder, 25 - screw feeder, 26 - transport trolley electric drive, 27, 29 - trolley position monitoring sensors, 28 - lower sensor container position, 30 - load cell sensor, 31 - container upper position sensor, 32, 35, 39, 40, 43, 46 - electric valve, 33 - LRW supply pipe to the dispenser, 34 - LRW supply pipe to the container, 36 - sensor top level, 37 - current level sensor non-contact, 38 - emergency liquid waste discharge pipe, 41 - compressed gas supply pipe, 42 - technological pipe ventilation pipe, 44 - pressure gauge, 45 - low level sensor, 47 - process water pipe, 48 - liquid fuel tank dispenser, 49 - liquid metal container inlet to the container .

The proposed installation works as follows.

The first stage - the preparatory stage begins with the installation of the container 1 with the mixing device 6 located in it, consisting of a support frame 7 with a metal ring 9 and a mixer 8, on the lifting platform 5 of the transport trolley 2, which is in the loading - unloading position, controlled by the extreme position sensor 27 On rail tracks 3, the trolley 2 with the container 1 is moved by means of the drive 26 to the kneading position of the solution, controlled by the extreme position sensor 29, and the elevator 4 along the upper position sensor of the container 31 providing close the container 1 with the technological cover 10, while providing a mechanical connection of the mixer 8 with the electric drive shaft 14. Into the loading box 20, connected to the air purification system from cement dust through the pipe 21, the required amount of cement is supplied to the load-lifting mechanism 22. The dispenser LRW 48 through the supply pipe 33 with the valve 32 open, waste is fed into the lower part of the dispenser 48, controlling their quantity by the current level sensor non-contact 37, the lower level sensor 45 and the upper level sensor 36. When stizhenii predetermined level the valve 32 is closed. In the process of filling dispenser 48 with liquid radioactive waste, valves 43 and 39 are open, and valves 35, 40, 46 are in the closed position.

The second stage - the reception of waste in the container 1 begins by turning on the electric drive 15 of the mixer 8. Then open the valve 35 and discharge the waste into the container 1 through the pipe 49 through the drain pipe 34 on the dispenser 48 and the supply pipe of LRW 11 on the technological cover 10, while valves 32, 39, 40 and 46 are closed and valve 43 is open. The weight of the waste is controlled by the readings of the load cells 30, and the process gases are blown off through the pipe 12 on the process cover 10. If the waste is not drained into the container 1 or is slowly drained, close valve 43 and open valve 40 on the compressed air line, create a waste in the waste dispenser 48 the pressure of not more than 5 kgf / cm ^2, which is monitored by the pressure gauge 44, and the waste is poured into the container 1. After this operation the valve 35 is closed and 40 open and valve 43. Control of rotation of the stirrer is held probe rotation control m agitator 13.

The third stage - waste cementing begins simultaneously with the end of the second stage by turning on the rotary feeder 24 with the drive 23 of the screw feeder 25. Cement is fed into the container 1 through the nozzle 17 on the technological cover 10. The mass of the loaded cement is monitored according to the readings from the load cells 18. Cement level the solution in the container 1 is monitored by the level sensor 16. At the end of the unloading of a portion of cement from the cement batcher 19, the rotary feeder 24 is first turned off, and then after 15- 20 s screw feeder 25. The countdown of the mixing time begins. At the end of the mixing time of 1-3 minutes, the mixer 8 turns off.

The fourth stage - the final begins by undocking the container 1 from the technological cover 10 and lowering the container 1 to the lower position, controlled by the sensor 28. The drive 26 is turned on and the trolley 2 with the container 1 is moved to the loading - unloading position, controlled by the trolley 27 position sensor. the fourth stage in that the container 1 is closed with a lid and transported to storage.

As follows from the description of the work, the proposed installation has the following advantages over the prototype:

- provides an accurate calculated ratio of the mixed components in each container, eliminating the possibility of operator error when dosing the components of the cement;

- eliminates contamination with radioactive cement mortar of the space outside the container and damage to the level sensor by the mixer when mixing the cement;

- provides, regardless of the salinity and viscosity of LRW, guaranteed production of high-quality cement compounds.

The above advantages generally increase the reliability of the installation.

Claims (8)

1. Installation for cementing liquid radioactive waste, comprising a container mounted on a transport trolley with a lifting platform and equipped with a mixing device, a container lift, a technological cover of the container, nodes for supplying liquid radioactive waste and cement connected to the technological cover, sensors and communication elements between the nodes characterized in that the mixing device of the container is made in the form of a support frame with a mixer fixed on it, while the support frame is provided in the upper part with a metal ring made with the possibility of docking the container with the technological cover, the liquid radioactive waste supply unit is made in the form of a dosing tank equipped with a manometer, lower, upper and current level sensors, waste reception pipes, compressed air and process water, waste discharge pipes, emergency drains and process gases, while the outlet pipe of the waste from the metering device is connected by a pipeline to the technological cover of the container, the cement supply unit is made in the form capacity, equipped with a loading box on top and a rotary feeder on the bottom, connected in series with a screw feeder and a technological cover of the container. 2. Installation according to claim 1, characterized in that the waste reception pipe in the dosing container is installed with the possibility of supplying waste to the lower part of the said container. 3. Installation according to claim 1, characterized in that the supporting frame of the mixing device is made in the form of a welded frame. 4. Installation according to claim 1, characterized in that the cement supply unit is equipped with load cells, a load-lifting mechanism and is connected to a cement dust air purification system. 5. Installation according to claim 1, characterized in that the node supplying liquid radioactive waste on the nozzles of the metering tank contains valves with an electric actuator. 6. Installation according to claim 1, characterized in that the technological cover of the container is equipped with a non-contact sensor for monitoring the level of the contents of the container, a sensor for monitoring the rotation of the mixer, a sensor for the upper position of the container and a nozzle for blowing off the process gases associated with the ventilation system. 7. Installation according to claim 1, characterized in that the transport trolley with a lifting platform is equipped with load cells. 8. Installation according to claim 1, characterized in that the transport trolley is arranged to move along rail tracks, which are equipped with sensors for monitoring the position of the trolley and a sensor for lower monitoring the position of the container.