CN114131343A

CN114131343A - Preparation method of special steel shot for removing nuclear waste metal radioactivity

Info

Publication number: CN114131343A
Application number: CN202111426653.2A
Authority: CN
Inventors: 雷洁珩; 罗鹏; 李霖晖; 黄灿裕; 钟林; 雷泽勇; 邓健; 雷林
Original assignee: University of South China
Current assignee: University of South China
Priority date: 2021-11-27
Filing date: 2021-11-27
Publication date: 2022-03-04

Abstract

The preparation method of the special steel shot for removing the radioactivity of the nuclear waste metal is applied to a special steel shot preparation system for removing the radioactivity of the nuclear waste metal and is used for preparing the steel shot. The special steel shot preparation system for removing the radioactivity of the nuclear waste metal comprises a shot blasting decontamination device, a metal cutting machine, a metal shredder, a metal compression packer, a metal smelting feeding assembly and a pill making equipment assembly; the preparation method of the steel shot comprises the following steps: surface shot blasting; fragmentizing treatment; compressing and packaging; feeding in a cooling furnace; smelting metal; and (5) preparing steel shots. The method takes nuclear waste metal as a raw material to prepare the steel shot special for decontaminating metal nuclei, no additional radioactive waste is generated in the preparation process of the steel shot, the steel shot can be recycled for many times through a cleaning process in the using process, and the requirement of minimizing the radioactive waste is fully met.

Description

Preparation method of special steel shot for removing nuclear waste metal radioactivity

Technical Field

The invention relates to the technical field of metal nuclear decontamination, in particular to a preparation method of a special steel shot for removing radioactivity of nuclear waste metal.

Background

With the rapid development of the nuclear industry, nuclear waste metals generated by nuclear power plants and nuclear industry enterprises also show a trend of increasing year by year. The nuclear waste metal can be classified into three grades, namely high, medium and low according to the radioactivity, wherein the nuclear waste metal with high radioactivity and medium radioactivity is generally difficult to utilize and can only be buried, but the burying place is very limited and is difficult to find.

If the radioactive decontamination degradation can be performed on the nuclear waste metal (i.e. the surface layer metal with relatively high radioactivity of the nuclear waste metal is stripped, and only the inner layer metal with relatively low radioactivity is reserved), the recycling of the nuclear waste is facilitated, which is equivalent to reducing the storage capacity of the nuclear waste and reducing the storage management cost of the nuclear waste, and has very important practical significance.

The shot blasting treatment is also called shot blasting reinforcement, and is an effective method for reducing the fatigue of the part and prolonging the service life, wherein high-speed shot flow is sprayed on the surface of the part to enable the surface layer of the part to generate plastic deformation so as to form a reinforcing layer with a certain thickness, and higher residual stress is formed in the reinforcing layer.

Researches show that the shot blasting treatment can be applied to radioactive decontamination of the nuclear waste metal, can effectively strip stains, rusts and radioactive substance layers on the surface of the nuclear waste metal and has the effect of radioactive decontamination. At present, no precedent for actually manufacturing steel shots by using nuclear waste metal and applying the manufactured steel shots to radioactive decontamination of the nuclear waste metal is seen in China.

The media (consumable materials) for shot blasting treatment are steel shots, when the steel shots are in contact with the nuclear waste metal for a certain time, the steel shots can be polluted by radioactivity, secondary pollution is caused if the steel shots are continuously used, namely, the radioactive decontamination is carried out on the nuclear waste metal, and meanwhile, new radioactive waste is generated, and waste compatibilization is generated. In addition, aiming at the steel shots infected with radioactivity, a safe, quick and effective radioactive decontamination means is lacked at present.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for preparing a special steel shot for removing the radioactivity of nuclear waste metal, wherein the special steel shot for removing the radioactivity of the nuclear waste metal is prepared by taking the nuclear waste metal as a raw material, no radioactive waste is additionally generated in the preparation process and the use process of the steel shot, and the requirement of minimizing the radioactive waste can be fully met.

The technical scheme of the invention is as follows: the preparation method of the special steel shot for removing the radioactivity of the nuclear waste metal is applied to a special steel shot preparation system for removing the radioactivity of the nuclear waste metal and is used for preparing the steel shot;

the special steel shot preparation system for removing the radioactivity of the nuclear waste metal comprises a shot blasting decontamination device, a metal cutting machine, a metal shredder, a metal compression packer, a metal smelting and feeding assembly and a shot making equipment assembly;

the shot blasting decontamination device comprises a spray gun, a sand-dust separator, a sand-dust collector, a steel shot cleaning machine, a steel shot returning device, a dry ice supply device, a high-pressure air source and negative-pressure air extraction equipment;

a confluence cavity, a steel shot injection channel and a steel shot recovery channel are arranged in the spray gun; the front end of the shot injection channel and the front end of the shot recovery channel are respectively communicated to the rear end of the converging cavity, and the front end of the converging cavity, the rear end of the shot injection channel and the rear end of the shot recovery channel respectively form a shot blasting operation port, a shot inlet A and a shot outlet A on the spray gun;

the sand-dust separator comprises a screening bin, a recovery bin and a tee joint which are sequentially arranged from top to bottom; the two sides of the upper end of the screening bin are respectively provided with a steel shot inlet B and a sand dust outlet, and the lower end of the screening bin is provided with a blast port A, a steel shot falling port and a steel shot outlet B; the steel shot inlet B is communicated with the steel shot outlet A of the spray gun through a gas path pipeline; an electric control valve A is arranged on the steel shot falling port; an electric control valve D is arranged on the steel shot outlet B; an opening which is opposite to the steel shot falling opening A of the screening bin is formed in the upper end of the recovery bin, a steel shot outlet C is formed in the lower end of the recovery bin, and a negative pressure exhaust opening and a steel shot returning opening are formed in the side wall of the recovery bin; the tee joint is provided with a first port, a second port and a third port, the first port is connected to a steel shot outlet C of the recovery bin, and the second port is communicated with a steel shot inlet A of the spray gun through a gas path pipeline;

the sand dust collector comprises a dust collecting bin and a filter element arranged in the inner cavity of the dust collecting bin; the filter element divides the inner cavity of the dust collecting bin into an upper cavity and a lower cavity which are not communicated with each other, and the outer wall of the dust collecting bin is provided with a sand dust inlet communicated with the lower cavity and a filtered air outlet communicated with the upper cavity; the sand dust inlet is communicated with a sand dust outlet of the screening bin through a gas path pipeline;

the steel shot cleaning machine comprises an outer cylinder body, an inner cylinder body, a bracket A, an electric push rod X and a motor; one end of the outer cylinder body is provided with a steel shot outlet D, a dry ice inlet, a waste gas outlet and a steel shot inlet D, the center and the lower edge of the other end are respectively provided with a crankshaft through hole and a slag discharge hole, and the slag discharge hole is provided with an electric control valve B; the outer cylinder body is rotatably connected with a cover plate on the steel shot outlet D, and the cover plate is rotated to open or close the steel shot outlet D; the waste gas outlet of the outer cylinder is communicated with the sand dust inlet of the dust collection bin through a gas path pipeline; the steel shot inlet D of the outer cylinder body is connected with the steel shot outlet B of the screening bin through a pipeline; one end of the inner cylinder body is provided with an opening, the other end of the inner cylinder body is provided with an end plate, a cleaning cavity is arranged in the inner cylinder body, and a hollow hole is formed in the outer circular surface; the inner cylinder body is rotatably arranged in the outer cylinder body, an annular cavity is formed between the inner cylinder body and the outer cylinder body, and the opening of the inner cylinder body is opposite to and closely adjacent to the steel shot outlet D, the dry ice inlet, the waste gas outlet and the steel shot inlet D of the outer cylinder body; the lower end of the bracket A is arranged on the ground, and the upper end of the bracket A is hinged with the outer wall of the outer cylinder; the lower end of the electric push rod X is hinged to the ground, the upper end of the electric push rod X is hinged to the outer wall of the outer cylinder body and used for driving the outer cylinder body to rotate around the hinged position of the outer cylinder body in a vertical plane, and therefore the steel shot outlet D faces obliquely upwards or obliquely downwards; when the steel shot outlet D faces obliquely upward, the cover plate is attached to the steel shot outlet D to close the steel shot outlet D, and when the steel shot outlet D faces obliquely downward, the cover plate is separated from the steel shot outlet D to open the steel shot outlet D; the motor is fixedly arranged on the end surface of one side of the outer cylinder body, a crankshaft of the motor extends into the outer cylinder body through a crankshaft through hole and is fixedly connected with an end plate of the inner cylinder body, and the crankshaft of the motor rotates to drive the inner cylinder body to rotate circumferentially relative to the outer cylinder body;

the steel shot returning device comprises a returning bin, a bracket B and an electric push rod Y; the upper end of the trip-return bin is provided with a steel shot inlet E, the lower end of the trip-return bin is provided with a steel shot outlet E, and the steel shot inlet E of the trip-return bin is positioned right below the steel shot outlet D of the outer barrel body; the lower end of the bracket B is fixedly arranged on the ground, and the upper end of the bracket B is hinged with the outer wall of the leave-return bin; the lower end of the electric push rod Y is hinged to the ground, the upper end of the electric push rod Y is hinged to the outer wall of the refuge bin and used for driving the refuge bin to rotate around the hinged position of the refuge bin in a vertical plane, and the steel shot outlet E faces to the obliquely upper side or the obliquely lower side;

a dry ice storage cavity is arranged in the dry ice supply device, and a high-pressure air inlet, a dry ice feeding port and a dry ice output port which are communicated with the dry ice storage cavity are arranged on the outer wall of the dry ice supply device; the dry ice output port is communicated with a dry ice inlet of the steel shot cleaning machine through an air path pipeline;

the high-pressure air source is used for outputting compressed air and is respectively communicated with a blast orifice A of the screening bin, a third port of the three-way joint and a high-pressure air inlet of the dry ice supply device through an air path pipeline;

the negative pressure air extraction equipment is used for providing negative pressure and is respectively communicated with the filtered air outlet of the dust collection bin and the negative pressure air outlet of the recovery bin through an air passage pipeline;

the metal compression packer comprises a box body, an X-direction propelling component, a Y-direction propelling component, a top overturning component and a discharging control component;

the box body is in a hollow cuboid shape, a compression cavity is arranged in the box body, the upper end of the box body is provided with a material inlet and a material outlet communicated with the compression cavity, the side walls of the four sides of the box body are clockwise named as a first wall, a second wall, a third wall and a fourth wall respectively, the lower end of the first wall, which is close to the second wall, is provided with a rectangular opening A communicated with the compression cavity, the lower end of the fourth wall is provided with a rectangular opening B communicated with the compression cavity, a corner gap is arranged between the lower end of the third wall and the bottom wall of the box body, the corner gap is formed by communicating a rectangular opening C arranged on the third wall with a rectangular opening D arranged on the bottom wall of the box body, and the rectangular opening C is over against the rectangular opening A;

the X-direction propelling component comprises an X-direction hydraulic cylinder and an X-direction push plate connected to the end of a piston rod of the X-direction hydraulic cylinder; the cylinder body of the X-direction hydraulic cylinder is fixedly arranged on the fourth wall of the box body and is positioned outside the compression cavity; the X-direction push plate is driven by the X-direction hydraulic cylinder to do horizontal reciprocating linear movement, and then the X-direction push plate is changed between being flush with the rectangular opening B and extending into the compression cavity, and the moving direction of the X-direction push plate is perpendicular to the second wall;

the Y-direction propelling component comprises a Y-direction hydraulic cylinder and a Y-direction push plate connected to the end of a piston rod of the Y-direction hydraulic cylinder; the cylinder body of the Y-direction hydraulic cylinder is fixedly arranged on the first wall of the box body and is positioned outside the compression cavity; the Y-direction push plate is driven by the Y-direction hydraulic cylinder to do horizontal reciprocating linear movement, and then the movement is changed between the position where the Y-direction push plate is flush with the rectangular opening A and the position where the Y-direction push plate extends into the compression cavity, and the movement direction of the Y-direction push plate is parallel to the second wall;

the top overturning assembly comprises a rotating plate and an overturning hydraulic cylinder; one end of the rotating plate is provided with a fourth hinge joint, and the middle part of the rotating plate is provided with a fifth hinge joint; the cylinder body of the turning hydraulic cylinder is hinged to the upper end of the fourth wall, the end of a piston rod of the turning hydraulic cylinder is hinged to a fifth hinge position of the rotating plate, and the piston rod of the turning hydraulic cylinder stretches and retracts to drive the rotating plate to rotate around the fourth hinge position in a vertical plane, so that a feed port and a discharge port of the box body are closed or opened;

the discharging control assembly comprises a rotating shaft, a folded plate and a discharging hydraulic cylinder; the rotating shaft is horizontally arranged and movably mounted at the upper end of the third wall and is arranged in parallel with the third wall, one end of the rotating shaft is fixedly connected with the upper end of the plate A, and the other end of the rotating shaft is hinged with the end of a piston rod of the discharging hydraulic cylinder; the folded plate is composed of a plate A and a plate B which are perpendicular to each other and connected at the side edges, the folded plate is arranged at the corner gap, and the upper end of the plate A is fixedly connected with the rotating shaft; the cylinder body of the discharging hydraulic cylinder is hinged to the lower end of the second wall, and a piston rod of the discharging hydraulic cylinder stretches to drive the rotating shaft to rotate, so that the folded plate is driven to rotate around the rotating shaft, and the folded plate is switched between a filling state and a discharging state; when the folded plate is in a vacancy filling state, the surface of the plate A in the compression cavity is flush with the surface of the third wall in the compression cavity, and the surface of the plate B in the compression cavity is flush with the surface of the bottom wall of the box body in the compression cavity; when the folded plate is in a discharging state, the plate A inclines towards the outer side of the compression cavity, and the plate B inclines towards the upper end of the compression cavity;

the metal smelting feeding assembly comprises a main frame, a vertical elevator, a smelting furnace component, a trolley component, a feeding butt joint mechanism, a negative pressure dust removal mechanism and a material conveying mechanism;

the main frame is sequentially provided with a first layer bottom plate and a second layer bottom plate from bottom to top, a first layer space is formed between the first layer bottom plate and the second layer bottom plate, a second layer space is formed at the upper end of the second layer bottom plate, and a communication port for communicating the first layer space with the second layer space is formed in the second layer bottom plate;

the vertical elevator is fixedly arranged on the main frame and positioned between the first-layer space and the second-layer space, the lower end of the vertical elevator is provided with a material inlet communicated to the first-layer space, and the upper end of the vertical elevator is provided with a material outlet communicated to the second-layer space;

the smelting furnace component comprises a tilting platform, a smelting furnace and a tilting hydraulic cylinder; the tipping platform is hinged at the communication port of the second floor bottom plate and rotates around the hinge position to a vertical plane; a smelting cavity is arranged in the smelting furnace, a feed opening communicated to the smelting cavity and a drainage groove communicated to the feed opening are formed in the upper end of the smelting furnace, the upper end of the outer wall of the smelting furnace is fixedly connected with the tilting platform, and the smelting furnace is positioned at a communication opening of the second floor and between the first floor space and the second floor space; the turnover hydraulic cylinder is arranged between the first floor and the smelting furnace, the lower end of the turnover hydraulic cylinder is hinged to the first floor, the upper end of the turnover hydraulic cylinder is hinged to the lower surface of the tipping platform, and the turnover hydraulic cylinder is used for driving the tipping platform to rotate around the hinged position of the tipping platform so as to drive the smelting furnace to rotate and enable the smelting furnace to be switched between a working state and a material pouring state; the smelting furnace is in a vertical posture in a working state, and a feeding port is vertically upward; the smelting furnace is in an inclined posture in a material pouring state, and smelting liquid in the smelting cavity can be poured out through the feeding port and the drainage groove;

the trolley component comprises a guide rail, a trolley, an electric push rod B and a positioning sleeve; the number of the guide rails is two, and the two guide rails are arranged in parallel and fixedly arranged on the second-layer bottom plate and are distributed on two sides of a feed opening of the smelting furnace; the two guide rails are arranged perpendicular to the drainage groove of the smelting furnace, one guide rail is relatively close to the drainage groove, and the other guide rail is relatively far away from the drainage groove; the trolley comprises a trolley body and electric wheels; the vehicle body is provided with a hollow hole A and a hollow hole B; the electric wheel is arranged at the lower end of the vehicle body; the trolley is movably arranged on the two guide rails through electric wheels; the electric push rod B is fixedly connected to one end of the trolley body and does vertical lifting movement; the positioning sleeve is fixedly arranged on the tilting platform and is positioned at the lower end of the electric push rod B; when the trolley is located at the first position, the electric push rod B is opposite to the positioning sleeve up and down, and the electric push rod B extends into the inner hole of the positioning sleeve to lock the position of the trolley;

the feeding butt joint mechanism comprises an outer funnel, an inner funnel and a traveling crane; the outer funnel is fixedly arranged in a hollow hole A of the vehicle body and is in a horn mouth shape with a large upper part and a small lower part; the inner funnel is in a horn mouth shape with a large upper part and a small lower part, the inner funnel is matched with the inner hole of the outer funnel in shape, and the upper end of the inner funnel is provided with a hanging lug for butting and hanging; the travelling crane is arranged in the second-layer space and used for controlling the inner funnel to move so as to enable the inner funnel to be butted with or separated from the outer funnel; when the inner funnel is butted with the outer funnel, the lower port of the inner funnel extends into a smelting cavity of a smelting furnace through a feeding port of the smelting furnace;

the negative pressure dust removing mechanism comprises a dust collecting cover and a negative pressure dust remover; the dust hood is internally provided with an air passage channel, the air passage channel forms a dust collecting port and a dust discharging port at two ends of the dust hood respectively, the dust hood is arranged on the trolley and is positioned in the hollow hole B of the trolley, and the dust discharging port and the dust collecting port are positioned at the upper end and the lower end of the hollow hole B respectively; the negative pressure dust remover is provided with an air inlet and an air outlet, a filter element is arranged in the negative pressure dust remover, and the air inlet of the negative pressure dust remover is connected with a dust exhaust port of the dust hood through an air pipe;

the material conveying mechanism comprises a support, a belt conveyor A and an upper traction assembly; the support is fixedly arranged in the second-layer space; the belt conveyor A is hinged on the support and rotates around a vertical plane of the hinged seat, so that the belt conveyor A is switched between a conveying state and an avoiding state; the vertical elevator is used for lifting materials discharged by the vertical elevator into the smelting furnace in a conveying state, and avoids a lifting moving path of the inner hopper, a turning path of the smelting furnace and a turning path of the tipping platform in an avoiding state; the upper traction assembly is associated with the belt conveyor A to drive the belt conveyor A to rotate around the hinged part of the belt conveyor A;

the trolley is sequentially provided with a first position, a second position and a third position along the moving path of the guide rail; when the trolley is positioned at the first position, the lower port of the outer funnel is vertically opposite to the feed inlet of the smelting furnace in a working state; when the trolley is positioned at the second position, the dust collecting port of the dust collecting cover is vertically opposite to the feed inlet of the smelting furnace in a working state; when the trolley is at the third position, the rotation paths of the trolley and the tipping platform are staggered up and down; the outer funnel and the inner funnel can be butted or separated only when the trolley is in the first position;

the pelleting equipment assembly comprises a centrifugal atomization pelleting machine, a vibration screening machine and a heat treatment furnace; the centrifugal atomization pill making machine comprises a shell, a motor B and a turntable; the shell is internally provided with a pill making cavity, and the upper end of the shell is provided with a bell mouth communicated with the pill making cavity; the motor B is fixedly arranged at the bottom of the pelleting cavity of the shell, and the shaft of the motor B vertically extends upwards; the center of the upper surface of the turntable is provided with a pit and a plurality of molten steel flowing grooves which are radially distributed around the center point of the pit, and two ends of each molten steel flowing groove are respectively communicated to the edge of the turntable and the edge of the pit; the center of the lower end of the turntable is fixedly connected with a crankshaft of the motor, and a pit of the turntable is positioned right below the bell mouth;

before preparing the steel shots, the preparation system of the special steel shots for metal nuclear decontamination is in an initial state, and in the initial state:

a. steel shots inside the shot blasting decontamination device are collected in a screening bin;

b. the feed and discharge port of the box body is opened;

c. the X-direction push plate is flush with the rectangular opening B;

d. the Y-direction push plate is flush with the rectangular opening A;

e. the folded plate is in a gap filling state;

f. the smelting furnace is in a working state;

g. the trolley is in a first position;

h. the inner funnel is butted with the outer funnel;

i. the belt conveyor A is in a conveying state;

j. the electric push rod B extends into an inner hole of the positioning sleeve;

k. the turntable is in a rotating state;

the preparation method of the steel shot comprises the following steps:

s01, surface shot blasting:

a. aiming at the nuclear waste metal with the inner wall surface, cutting the nuclear waste metal by a metal cutting machine to expose the inner wall surface of the nuclear waste metal so as to be convenient for carrying out surface shot blasting subsequently;

b. the shot blasting operation port of the spray gun is opposite to and propped against the surface of the nuclear waste metal, and then a high-pressure air source and negative-pressure air extraction equipment are started; under the combined action of a high-pressure air source and negative-pressure air extraction equipment, the steel shots circularly flow among the spray gun, the screening bin and the recovery bin;

in the step, when the steel shots flow through the spray gun, the moving path sequentially comprises a steel shot injection channel, a converging cavity and a steel shot recycling channel; after entering the converging cavity, the steel shots move towards the shot blasting operation opening and finally impact the metal surface, so that on one hand, stains, rust and radioactive substance layers on the metal surface are stripped, on the other hand, the steel shots rebound and change directions immediately and enter a steel shot recovery channel under the action of negative pressure;

in the step, after a high-pressure air source is started, the air is blown into the screening bin from bottom to top through a blast port A, and impurities, dust and fragments in the screening bin are blown to the upper area of the screening bin;

in the step, after a high-pressure air source is started, air is blown into a shot injection channel of the spray gun through a three-way joint and a shot inlet A, so that a shot outlet C connected to the three-way joint generates negative pressure, the shots are discharged from the shot outlet C of a recovery bin under the action of the negative pressure, then enter a gas path pipeline, and are pushed by wind to flow towards the shot injection channel of the spray gun;

in the step, after the negative pressure air extraction equipment is started, negative pressure is generated in an upper cavity of the dust collection bin, a lower cavity of the dust collection bin, an upper region of the screening bin and a steel shot recovery channel of the spray gun in sequence; under the action of negative pressure, impurities, dust and debris in the upper area of the screening bin enter the lower cavity of the dust collecting bin, so that the impurities, the dust and the debris are settled at the bottom of the lower cavity or are collected by the filter element;

in the step, the valves on the air path pipelines which are not involved are in a closed state, and the valves on the air path pipelines which are involved are in an open state;

s02, fragmenting:

cutting the nuclear waste metal subjected to surface shot blasting into the size meeting the feeding requirement of a metal shredder by a metal cutting machine; putting the cut nuclear waste metal into a metal shredder for shredding;

s03, compression and packaging:

a. after the crushed metal materials formed by shredding are transferred into a compression cavity of the box body, the turning hydraulic cylinder is started to drive the rotating plate to rotate around the fourth hinge joint in a vertical plane, so that on one hand, a feed port and a discharge port of the box body are sealed, and on the other hand, the crushed metal materials in the compression cavity of the box body are compressed in the height direction;

b. the X-direction hydraulic cylinder is started to drive the X-direction push plate to move towards the direction close to the second wall, metal particles in the compression cavity are compressed in the horizontal X direction, and when the X-direction push plate moves to be flush with the side edge of the rectangular opening A, the movement is stopped;

c. the Y-direction hydraulic cylinder is started to drive the Y-direction push plate to move towards the direction close to the third wall, metal particles in the compression cavity are compressed in the horizontal Y direction, and a cuboid block, which is hereinafter referred to as a metal block, is formed after the metal particles are compressed;

d. the X-direction hydraulic cylinder and the Y-direction hydraulic cylinder are started out in sequence, and the X-direction push plate and the Y-direction push plate are respectively driven to return to the original positions;

e. the discharging hydraulic cylinder is started, and the folded plate is driven to rotate through the rotating shaft, so that the folded plate rotates from a vacancy state to a discharging state, and the compressed cuboid blocks are tilted and discharged from the compression cavity of the box body;

in this step, the moving direction of the X-direction push plate is defined as the X direction, the moving direction of the Y-direction push plate is defined as the Y direction, and the side edge is the side edge of the rectangular opening A relatively far away from the second wall;

s04, feeding in a cooling furnace:

a. the metal blocks are sent into a vertical elevator through a material inlet, and after the vertical elevator lifts the metal blocks from a first-layer space to a second-layer space, the metal blocks are driven to be discharged out of the vertical elevator from a material outlet;

b. after being discharged from the material outlet, the metal blocks enter the conveying belt A through the feeding end A of the belt conveyor A, and move to the discharging end A of the belt conveyor A along with the conveying belt A;

c. after being discharged from a discharge end A of a belt conveyor A, the metal blocks enter a smelting cavity of a smelting furnace through an inner funnel;

d. after the feeding is finished, the winch is started to pull the belt conveyor A to rotate upwards around the first hinge joint, so that the belt conveyor A is changed from a conveying state to an avoiding state;

e. the lifting hook at the lower end of the travelling crane hooks the hanging lug at the upper end of the inner funnel, and the travelling crane is operated to lift the inner funnel upwards so as to completely separate the inner funnel from the outer funnel;

s05, smelting metal:

a. the electric push rod B is withdrawn from the inner hole of the positioning sleeve to release the position locking of the trolley, and then the trolley is moved from the first position to the second position to ensure that the dust collecting port of the dust collecting cover is over against the feed opening of the smelting furnace;

b. starting the heating function of the smelting furnace to smelt the metal blocks; in the smelting process, on one hand, the continuous operation of the negative pressure dust collector is ensured, so that the volatile gas generated by smelting enters the negative pressure dust collector through the dust collecting cover, the radioactive nuclide in the gas is intercepted in a filter element of the negative pressure dust collector, the filtered gas is discharged to the atmosphere through the negative pressure dust collector, and on the other hand, the slag generated by smelting is manually cleaned in real time;

c. after smelting is finished, the driving trolley moves from the second position to the third position, so that the rotation paths of the trolley and the tipping platform are staggered up and down;

s06, preparing steel shots:

a. controlling the turning hydraulic cylinder to act, so that the smelting liquid in the smelting furnace is discharged through the feeding port and the drainage groove in sequence, enters the pelleting cavity of the shell through the bell mouth, falls into the pit of the rotating turntable, is thrown out through the molten steel flowing groove under the action of centrifugal force to form molten steel droplets, falls into cooling water at the lower part of the pelleting cavity of the shell to form steel shots, and the steel shots are used for surface shot blasting in the step S01;

b. screening out steel shots with the diameter of 0.25mm-2mm by using a vibration screening machine, and then sequentially normalizing, quenching and tempering the steel shots by using a heat treatment furnace to ensure that the steel shots reach the hardness requirement of HRC more than 49.

The further technical scheme of the invention is as follows: when the shot blasting decontamination device continuously operates for 4-10min, starting a steel shot decontamination process to remove the radioactive nuclides stained on the surface of the steel shot; before the cleaning process is executed, the shot blasting decontamination device is in the following state:

1. the outer cylinder body rotates until the steel shot outlet D faces to the obliquely upper part;

2. closing an electric control valve A on a steel shot falling port of the screening bin;

3. closing an electric control valve D on a steel shot outlet B of the screening bin;

4. closing an electric control valve B on a slag discharge port of the steel shot cleaning machine;

5. an electric control valve C on a material receiving hopper of the steel shot sending-back device is opened;

the steel shot decontamination process comprises the following steps:

s01, collecting the steel shots in a screening bin:

the shot blasting operation opening of the spray gun is opposite to and props against a plane, so that the shot blasting operation opening is closed; then starting a high-pressure air source and negative pressure air extraction equipment to enable the steel shots to be completely collected into the screening bin along the flow path of the recovery bin, the spray gun and the screening bin, and then closing the high-pressure air source and the negative pressure air extraction equipment;

in the step, after the negative pressure air extraction equipment is started, negative pressure is generated in an upper cavity of the dust collection bin, a lower cavity of the dust collection bin, an upper region of the screening bin and a steel shot recovery channel of the spray gun in sequence;

in the step, when the steel shots flow through the spray gun, the moving path sequentially comprises a steel shot injection channel, a converging cavity and a steel shot recycling channel; after entering the converging cavity, the steel shots move towards the shot blasting operation port and finally impact the metal surface, and when the steel shots impact the plane, the steel shots immediately rebound and change direction and enter the steel shot recovery channel under the action of negative pressure;

s02, conveying the steel shots into a steel shot cleaning machine:

opening an electric control valve D on a steel shot outlet B of the screening bin to enable the steel shots in the screening bin to enter the inner cavity of the inner barrel through a steel shot inlet D on the outer barrel;

in the step, the screening bin is positioned above the steel shot cleaning machine, so that the steel shots can naturally flow through self gravity;

s03, cleaning steel shots:

a. putting dry ice particles into a dry ice storage cavity of a dry ice supply device through a dry ice feeding port, and simultaneously performing the following three operations:

1. the motor is started to drive the inner barrel to rotate circumferentially relative to the outer barrel, so that the steel shots positioned in the inner cavity of the inner barrel roll fully, on one hand, all the surfaces of the steel shots have the chance of contacting dry ice particles, on the other hand, a small part of radioactive nuclides on the surfaces of the steel shots are peeled off through the mutual collision action among the steel shots, and the scraps generated by collision enter the annular cavity through the hollow holes and are collected at the lowest part of the annular cavity;

2. starting a high-pressure air source to enable dry ice particles in the dry ice storage cavity to sequentially pass through a dry ice output port of the dry ice supply device and a dry ice inlet of the outer cylinder body and enter the inner cavity of the inner cylinder body; after entering the inner cavity of the inner barrel body, the dry ice particles directly impact the surface of the steel shot and strip most of radioactive nuclides on the surface of the steel shot through sublimation;

3. starting the negative pressure air extraction equipment to enable the upper cavity of the dust collection bin, the lower cavity of the dust collection bin and the inner cavity of the inner cylinder body to generate negative pressure in sequence; under the action of negative pressure, the gas containing the radioactive nuclide in the inner cavity of the inner cylinder body sequentially passes through a waste gas outlet of the outer cylinder body, a sand and dust inlet of the dust collection bin, a lower cavity of the dust collection bin, the filter element, an upper cavity of the dust collection bin and negative pressure air extraction equipment and is discharged to the outside; in the process, when the gas flows through the filter element, the radioactive nuclide is retained in the filter element, so that the gas finally discharged to the outside is ensured to be pollution-free gas;

b. after the steel shot is cleaned, closing the high-pressure air source, the negative-pressure air extraction equipment and the motor, and opening the electric control valve B on the slag discharge port of the outer cylinder body to discharge the scraps in the annular cavity;

s04, conveying the steel shots into a recovery bin:

a. the electric push rod X acts to enable the outer cylinder body to rotate around the hinged position of the outer cylinder body in a vertical plane, and when the outer cylinder body rotates to the position where the steel shot outlet D faces obliquely downwards, the cover plate immediately rotates under the dead weight, so that the steel shots in the inner cavity of the inner cylinder body are discharged through the steel shot outlet D;

b. the steel shots are discharged and then fall freely, and enter the refunding bin through a steel shot inlet E;

c. the electric push rod Y is started to drive the dispatching and returning bin to rotate around the hinged position of the dispatching and returning bin on a vertical plane, when the dispatching and returning bin rotates until the steel shot outlet E faces obliquely downward, the negative pressure air extraction equipment is started to enable negative pressure to be sequentially generated in the recovery bin and the dispatching and returning bin, and under the action of the negative pressure, the steel shots in the dispatching and returning bin sequentially pass through the steel shot outlet E of the dispatching and returning bin and the steel shot dispatching and returning port of the recovery bin to enter the recovery bin;

in this step, the valves on the gas path pipelines not involved are in a closed state, and the valves on the gas path pipelines involved are in an open state.

In a further technical scheme of the invention: in step S03 of the steel shot decontamination procedure, the dry ice particles were cylindrical in shape, with a diameter of 3mm and a length of 5.5 mm.

In a further technical scheme of the invention: in step S06 of the steel shot preparation method, the steel shots with the diameter less than 0.25mm and the diameter more than 2mm are sent back to the smelting furnace for smelting again.

In a further technical scheme of the invention: in the step S04 of the steel shot preparation method, when the inner funnel is butted with the outer funnel, the distance between the lower port of the inner funnel and the bottom surface of a smelting cavity of the smelting furnace is 0-5 cm; be provided with disposable cushion in the lower port of interior funnel, the cushion plays the cushioning effect, can avoid the smelting chamber bottom surface of smelting furnace to be injured by the metal block pounding.

In a further technical scheme of the invention: in the step S05 of the steel shot preparation method, in the smelting process, the height difference exists between the dust-collecting hood and the feeding port, so that the condition in the smelting furnace can be observed conveniently, and if the smelting liquid crusts, manual intervention is immediately carried out, so that the furnace is prevented from being exploded.

The further technical scheme of the invention is as follows: in the S01 step of the steel shot preparing method and the S01 step of the steel shot decontamination process, the operator remotely controls the industrial robot arm to operate to grip the spray gun and control the spray gun to move.

In a further technical scheme of the invention: the trolley assembly further comprises a universal ball seat and a steel ball, the lower end of the universal ball seat is fixedly arranged on the second floor or the tipping platform and is positioned on the outer side of a guide rail relatively close to the drainage groove, a spherical pit for containing the steel ball is formed in the upper end of the universal ball seat, and the steel ball is movably arranged in the spherical pit of the universal ball seat; the universal ball seats are arranged at intervals and are arranged in a row parallel to the guide rail; when the trolley moves to any position along the guide rail, at least one steel ball on the universal ball seat is contacted with the lower surface of the trolley body; correspondingly, the trolley body of the trolley is a rectangular frame with four vertex angles, the electric wheels are only arranged at the three vertex angles at the lower end of the trolley body, and the electric wheels are not arranged at the lower end of one vertex angle of the trolley body, which is relatively close to the drainage groove; in the moving process of the trolley, the trolley is supported by the steel balls, so that the stability of the trolley in the moving process is ensured.

Compared with the prior art, the invention has the following advantages:

1. the method takes nuclear waste metal as a raw material to prepare the steel shot specially used for metal nuclear decontamination, no additional radioactive waste is generated in the steel shot preparation process, the volume reduction of the waste is realized, the steel shot can be recycled for many times through a cleaning process in the using process, and the requirement of minimizing the radioactive waste is fully met.

2. The preparation process of the steel shots comprises three steps of shot blasting, smelting and shot making, and the radiation dose in the nuclear waste metal is greatly reduced (the radiation dose can be reduced to meet the requirement of civil steel) through the two steps of shot blasting and smelting, and finally the steel shots with low radiation dose are produced and can be used by a shot blasting decontamination device, so that the recycling of the nuclear waste metal is realized;

regarding the shot blasting process: the shot blasting decontamination device can effectively strip stains, rusts and radioactive substance layers on the surface of the nuclear waste metal, and the radioactive decontamination effect is achieved;

regarding the smelting process: smelt nuclear waste metal through the smelting furnace, can make the inside radionuclide that remains of nuclear waste metal release, high temperature can make partly volatile radionuclide directly become gaseous volatilization, and another part radionuclide then can deposit in the slag that produces of smelting, collects the gas that volatilizees in the smelting process and the slag that produces, plays the effect of radioactive decontamination.

3. The shot blasting decontamination device has the following advantages:

a. the steel shots circularly flow among the spray gun, the screening bin and the recovery bin, the circulating path is relatively short, the abrasion of the steel shots is relatively small, and the service life is longer;

b. the spray gun can perform decontamination operation by abutting against the surface of the workpiece, the decontamination part and the decontamination time can be flexibly controlled by an operator, and the operation mode is very convenient;

c. dust and debris generated in the shot blasting decontamination operation process can be immediately collected in the dust collector without leaking outside, so that the radiation quantity of operators can be reduced to a greater extent;

d. the automatic cleaning of the steel shot can be realized, the radioactive nuclide stained on the surface of the steel shot can be fully removed through the cleaning process, and the recycling times of the steel shot when the steel shot is used for radioactive decontamination of the surface of the nuclear waste metal are prolonged.

4. The metal smelting feeding assembly has very high automation degree, the whole process of feeding, smelting and pouring basically does not need manual intervention, and a plurality of anti-interference structures (avoidance structures) are designed in a targeted manner according to the sequence and relative position relation of each part in the action process while the action requirements of each part are met;

a. in order to avoid interference with a furnace mouth (a drainage groove is formed in the furnace mouth) of a smelting furnace in the moving process of the trolley, on one hand, electric wheels which are relatively close to the lower ends of the top corners of the furnace mouth are removed (namely, the electric wheels are only arranged at the three top corners of the lower end of the trolley), and on the other hand, the trolley is supported in an auxiliary manner through universal ball seats and steel balls arranged on the two layers of bottom plates, so that the stability of the trolley in the moving process is ensured;

b. in order to avoid interference between the inner funnel and the belt conveyor A in the butt joint or separation process, on one hand, a hinge structure capable of rotating integrally is designed for the belt conveyor A, on the other hand, the upper drawing assembly provides rotating power for the belt conveyor A, and stability and reliability of the belt conveyor A in the rotating process are guaranteed.

5. The metal smelting feeding assembly has good reliability, various adverse factors existing in the working state of the metal smelting feeding assembly are fully considered, and various structures which are beneficial to improving the reliability are designed in a targeted manner;

a. in order to ensure that the trolley can be accurately aligned with a feeding port of a smelting furnace when in a first position and cannot shake or slide due to impact of materials, a locking structure in a specific state is designed for the trolley, namely, an electric push rod B is arranged at one end of the trolley, a positioning sleeve is arranged at the corresponding position of a tipping platform, when the trolley is positioned at the first position, the electric push rod B is vertically opposite to the positioning sleeve, and the electric push rod B extends into an inner hole of the positioning sleeve to lock the position of the trolley;

b. in order to avoid that the bottom surface of a smelting cavity of the smelting furnace is injured by materials when the materials are fed into a cold furnace, on one hand, a disposable soft cushion is arranged at the lower end opening of the inner funnel, and on the other hand, the distance between the lower end opening of the inner funnel and the bottom surface of the smelting cavity is only 0-5cm in a butt joint state; the material feeding device can play a good role in buffering when the material is fed into the cold furnace, and the bottom surface of a smelting cavity of the smelting furnace is prevented from being damaged by smashing;

c. in order to facilitate observation of the condition inside the smelting furnace at any time (through a feed inlet) in the smelting process, the dust hood is designed into a structure mode with adjustable height.

The invention is further described below with reference to the figures and examples.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic structural view of a shot blasting decontamination device;

FIG. 3 is a schematic structural diagram of a steel shot cleaning machine;

FIG. 4 is a schematic structural diagram of a steel shot refurbisher;

FIG. 5 is a schematic view of the structure of the spray gun;

FIG. 6 is a schematic view of a metal baler from one perspective;

FIG. 7 is a schematic view of the metal baler from another perspective;

FIG. 8 is a schematic structural view of a metal melting charging assembly;

FIG. 9 is a state diagram of the metal melting charging assembly at the completion of substeps e of shot making S04;

FIG. 10 is a state diagram of the metal melting charging assembly at the completion of substeps a of shot making S05;

FIG. 11 is a state diagram of the metal melting and feeding assembly at the completion of substeps d of the shot making S05;

FIG. 12 is an enlarged view of portion A of FIG. 9;

FIG. 13 is a schematic diagram of a centrifugal atomizing pelletizing machine.

Description of the drawings: the vertical lift is only shown in fig. 8 and not in fig. 9-11.

Illustration of the drawings: a shot blasting decontamination device 1; a spray gun 11; a merging chamber 111; a shot blasting operation port 1111; steel balls are shot into the channel 112; a steel ball inlet A1121; a steel ball recovery passage 113; a steel ball outlet A1131; a screening bin 121; a steel ball inlet B1211; a dust outlet 1212; tuyere a 1213; a steel ball drop opening 1214; steel ball outlet B1215; a recovery bin 122; a steel ball outlet C1221; a negative pressure vent 1222; a steel ball return port 1223; a three-way joint 123; a first port 1231; a second port 1232; a third port 1233; a dust collecting bin 131; an upper chamber 1311; a lower chamber 1312; a sand dust inlet 1313; filtered outlet 1314; a filter element 132; a steel ball cleaning machine 14; an outer cylinder 141; a steel ball outlet D1411; a dry ice inlet 1412; an exhaust outlet 1413; a steel ball inlet D1414; a slag discharge port 1415; a cover plate 1416; an inner cylinder 142; a hollowed-out hole 1421; a scaffold A143; an electric push rod X144; a motor 145; an annular cavity 146; a steel ball return device 15; a trip back bin 151; a steel ball inlet E1511; a steel ball outlet E1512; a receiving hopper 1513; a bracket B152; an electric push rod Y153; a high pressure gas inlet 161; a dry ice batch port 162; a dry ice outlet 163; a source of high pressure air 17; a negative pressure pumping device 18; a metal cutter 2; a metal shredder 3; a metal compression baler 4; a case 41; a first wall 411; a second wall 412; a third wall 413; a fourth wall 414; a bottom wall 415; an X-direction hydraulic cylinder 421; an X-direction pusher plate 422; a Y-direction hydraulic cylinder 431; a Y-direction pusher 432; a rotating plate 441; a roll-over hydraulic cylinder 442; a rotating shaft 451; a flap 452; a discharge hydraulic cylinder 453; a floor 511; a two-layer backplane 512; a communication port 513; a vertical lift 52; a material inlet 521; a material outlet 522; tipping the platform 531; a smelting furnace 532; a feeding port 5321; a drainage groove 5322; a turning hydraulic cylinder 533; a guide rail 541; a trolley 542; a universal ball seat 543; a steel ball 544; an electric push rod B545; a positioning sleeve 546; an outer funnel 551; an inner funnel 552; a hanging lug 5521; an electric push rod A561; a connecting frame 562; a dust cage 563; a support 571; a frame body A5721; a first hinge 57211; a second hinge joint 57212; a third hinge 57213; conveyor a 5722; the attachment frame 5731; wire rope 5732; a hoist 5733; a lower support member 574; a centrifugal atomizing pill making machine 6; a housing 61; a bell mouth 611; motor B62; a turntable 63; a pit 631; a molten steel flowing groove 632; a vibratory screening machine 64; a heat treatment furnace 65; belt conveyor B7; belt conveyor C8; belt conveyor D9.

Detailed Description

Example 1:

as shown in fig. 1 to 13, the special steel shot preparation system for removing the radioactivity of nuclear waste metal is used for preparing steel shots and comprises a shot blasting decontamination device 1, a metal cutting machine 2, a metal shredder 3, a metal compression packer 4, a metal smelting and feeding assembly and a shot making equipment assembly.

The metal shredder 3, the metal compression packer 4, the metal smelting feeding assembly and the pelleting equipment assembly are used in sequence in the process of radioactive decontamination of the nuclear waste metal. The shot blasting decontamination device 1 and the metal cutting machine 2 are used successively in the nuclear waste metal decontamination process (successive use does not limit successive use relationship, and the shot blasting decontamination device 1 can be used for firstly cutting by the metal cutting machine 2 and then decontaminating, or can be used for firstly decontaminating by the shot blasting decontamination device and then cutting by the metal cutting machine 2). Also, the use of the shot-blasting decontamination apparatus 1 and the metal cutter 2 is arranged before the use of the metal shredder 3.

The shot blasting decontamination device 1 comprises a spray gun 11, a sand-dust separator, a sand-dust collector, a steel shot cleaning machine 14, a steel shot dispenser 15, a dry ice supply device, a high-pressure air source 17 and negative-pressure air extraction equipment 18.

The spray gun 11 is internally provided with a confluence chamber 111, a shot injection passage 112, and a shot recovery passage 113. The front end of the shot injection channel 112 and the front end of the shot recovery channel 113 are respectively communicated to the rear end of the converging cavity 111, and the front end of the converging cavity 111, the rear end of the shot injection channel 112 and the rear end of the shot recovery channel 113 respectively form a shot blasting operation port 1111, a shot inlet A1121 and a shot outlet A1131 on the spray gun 11.

The sand-dust separator comprises a screening bin 121, a recovery bin 122 and a three-way joint 123 which are sequentially arranged from top to bottom. The two sides of the upper end of the screening bin 121 are respectively provided with a steel shot inlet B1211 and a sand dust outlet 1212, and the lower end of the screening bin 121 is provided with a blast port A1213, a steel shot falling port 1214 and a steel shot outlet B1215. The steel shot inlet B1211 is communicated with the steel shot outlet A1131 of the spray gun 11 through a gas pipeline. An electric control valve A is arranged on the steel shot falling port 1214. An electric control valve D is arranged on the steel shot outlet B1215. The upper end of the recovery bin 122 is provided with an opening which is opposite to the steel shot falling port 1214 of the screening bin 121, the lower end of the recovery bin 122 is provided with a steel shot outlet C1221, and the side wall of the recovery bin 122 is provided with a negative pressure air outlet 1222 and a steel shot returning port 1223. The three-way joint 123 is provided with a first port 1231, a second port 1232 and a third port 1233, the first port 1231 is connected to the shot outlet C1221 of the recycling bin 122, and the second port 1232 is communicated with the shot inlet a1121 of the spray gun 11 through the air path pipeline.

The dust collector includes a dust collecting chamber 131 and a filter element 132 installed in an inner chamber of the dust collecting chamber 131. The filter element 132 divides the inner cavity of the dust collecting bin 131 into an upper cavity 1311 and a lower cavity 1312 which are not communicated with each other, and the outer wall of the dust collecting bin 131 is provided with a sand dust inlet 1313 communicated with the lower cavity 1312 and a filtered air outlet 1314 communicated with the upper cavity 1311. The sand dust inlet 1313 is communicated with the sand dust outlet 1212 of the screening bin 121 through a gas pipeline.

The shot cleaning machine 14 includes an outer cylinder 141, an inner cylinder 142, a bracket a143, an electric push rod X144, and a motor 145. One end of the outer cylinder body 141 is provided with a steel shot outlet D1411, a dry ice inlet 1412, an exhaust gas outlet 1413 and a steel shot inlet D1414, the center and the lower edge of the other end are respectively provided with a crankshaft through hole and a slag discharge port 1415, and the slag discharge port 1415 is provided with an electric control valve B. The outer cylinder 141 is rotatably connected to a cover 1416 on the shot outlet D1411, and the cover 1416 is rotated to open or close the shot outlet D1411. The exhaust outlet 1413 of the outer cylinder 141 is communicated with the sand dust inlet 1313 of the dust collecting bin 131 through an air passage pipe. The steel shot inlet D1414 of the outer cylinder body 141 is connected with the steel shot outlet B1215 of the screening bin 121 through a pipeline. Interior barrel 142 one end is equipped with uncovered, and the other end is equipped with the end plate, and inside is equipped with the washing chamber, is equipped with fretwork hole 1421 on the excircle face, and fretwork hole 1421 is the bar hole, can supply the dust and the piece that the size is less than the shot to pass through. The inner cylinder 142 is rotatably mounted inside the outer cylinder 141 (via bearings) and forms an annular chamber 146 with the outer cylinder 141, and the opening of the inner cylinder 142 faces and is adjacent to the shot outlet D1411, the dry ice inlet 1412, the waste gas outlet 1413 and the shot inlet D1414 of the outer cylinder 141. The lower end of the bracket A143 is arranged on the ground, and the upper end is hinged with the outer wall of the outer cylinder 141. The lower end of the electric push rod X144 is hinged on the ground, the upper end is hinged with the outer wall of the outer cylinder body 141, and the electric push rod X144 is used for driving the outer cylinder body 141 to rotate around the hinged position of the outer cylinder body to a vertical plane, so that the steel shot outlet D1411 faces obliquely upwards or obliquely downwards. When the steel shot outlet D1411 faces obliquely upward, the cover plate 1416 is attached to the steel shot outlet D1411 to close the steel shot outlet D1411, and when the steel shot outlet D1411 faces obliquely downward, the cover plate 1416 is separated from the steel shot outlet D1411 to open the steel shot outlet D1411. The motor 145 is fixedly installed on an end surface of an outer side of the outer cylinder 141, a shaft thereof extends into the outer cylinder 141 through a shaft penetration hole and is fixedly connected with an end plate of the inner cylinder 142, and the shaft of the motor 145 rotates to drive the inner cylinder 142 to rotate circumferentially relative to the outer cylinder 141.

The shot-returning device 15 comprises a returning bin 151, a bracket B152 and an electric push rod Y153. The upper end of the trip-return bin 151 is provided with a shot inlet E1511, the lower end is provided with a shot outlet E1512, and the shot inlet E1511 of the trip-return bin 151 is positioned right below the shot outlet D1411 of the outer cylinder body 141. The lower end of the bracket B152 is fixedly arranged on the ground, and the upper end is hinged with the outer wall of the refuelling cabin 151. The lower end of the electric push rod Y153 is hinged on the ground, the upper end of the electric push rod Y153 is hinged with the outer wall of the refuge bin 151, and the electric push rod Y is used for driving the refuge bin 151 to rotate around the hinged position of the refuge bin in a vertical plane, so that the steel shot outlet E1512 faces obliquely upwards or downwards. The shot dispatcher 15 may receive the shot discharged from the shot washer 14 when the shot outlet E1512 is directed obliquely upward, and the shot dispatcher 15 may deliver the shot to the reclamation bin 122 when the shot outlet E1512 is directed obliquely downward.

The dry ice supplying device is internally provided with a dry ice storage cavity, and the outer wall of the dry ice supplying device is provided with a high-pressure air inlet 161, a dry ice feeding port 162 and a dry ice output port 163 which are communicated to the dry ice storage cavity. The dry ice outlet 163 is communicated with a dry ice inlet 1412 of the steel shot cleaning machine 14 through an air channel pipeline.

The high-pressure air source 17 is used for outputting compressed air, and the high-pressure air source 17 is respectively communicated with the blast opening A1213 of the screening bin 121, the third port 1233 of the three-way joint 123 and the high-pressure air inlet 161 of the dry ice supply device through air passage pipelines.

The negative pressure air extracting device 18 is used for providing negative pressure, and the negative pressure air extracting device 18 is respectively communicated with the filtered air outlet 1314 of the dust collecting bin 131 and the negative pressure air outlet 1222 of the recycling bin 122 through the air passage pipeline.

The metal baler 4 comprises a case 41, an X-direction propulsion assembly, a Y-direction propulsion assembly, a top tipping assembly and a discharge control assembly.

The box body 41 is in a hollow cuboid shape, a compression cavity is arranged in the box body, the upper end of the box body is provided with a feeding and discharging port communicated with the compression cavity, the four side walls of the box body are respectively named as a first wall 411, a second wall 412, a third wall 413 and a fourth wall 414 clockwise, the lower end of the first wall 411 close to the second wall 412 is provided with a rectangular opening A communicated with the compression cavity, the lower end of the fourth wall 414 is provided with a rectangular opening B communicated with the compression cavity, a corner notch is arranged between the lower end of the third wall 413 and the bottom wall 415 of the box body 41, the corner notch is formed by communicating a rectangular opening C arranged on the third wall 413 with a rectangular opening D arranged on the bottom wall 415 of the box body 41, and the rectangular opening C is over against the rectangular opening A.

The X-direction propelling assembly comprises an X-direction hydraulic cylinder 421 and an X-direction push plate 422 connected to the end of the piston rod of the X-direction hydraulic cylinder 421. The cylinder body of the X-direction hydraulic cylinder 421 is fixedly mounted on the fourth wall 414 of the case 41 and is located outside the compression chamber. The X-direction push plate 422 is driven by the X-direction hydraulic cylinder 421 to make horizontal reciprocating linear movement, so that the movement is changed between the position of being flush with the rectangular opening B and the position of extending into the compression cavity, and the movement direction of the X-direction push plate 422 is perpendicular to the second wall 412.

The Y-direction propelling assembly comprises a Y-direction hydraulic cylinder 431 and a Y-direction push plate 432 connected to the end of a piston rod of the Y-direction hydraulic cylinder 431. The cylinder body of the Y-direction hydraulic cylinder 431 is fixedly installed on the first wall 411 of the case 41 and is located outside the compression chamber. The Y-direction push plate 432 is driven by the Y-direction hydraulic cylinder 431 to do horizontal reciprocating linear movement, and then the movement is changed between the position of being flush with the rectangular opening A and the position of extending into the compression cavity, and the movement direction of the Y-direction push plate 432 is parallel to the second wall 412.

The top roll assembly includes a roll plate 441 and a roll cylinder 442. One end of the rotating plate 441 is provided with a fourth hinge 4411, and the middle part of the rotating plate 441 is provided with a fifth hinge. The cylinder body of the turning hydraulic cylinder 442 is hinged to the upper end of the fourth wall 414, the end of the piston rod of the turning hydraulic cylinder 442 is hinged to the fifth hinge of the rotating plate 441, and the piston rod of the turning hydraulic cylinder 442 stretches to drive the rotating plate 441 to rotate around the fourth hinge 4411 in a vertical plane, so as to seal or open the material inlet and outlet of the box 41.

The discharge control assembly includes a shaft 451, a flap 452, and a discharge cylinder 453. The rotating shaft 451 is horizontally arranged and movably installed at the upper end of the third wall 413, and is arranged parallel to the third wall 413, one end of the rotating shaft 451 is fixedly connected with the upper end of the plate A, and the other end of the rotating shaft 451 is hinged with the end of a piston rod of the discharging hydraulic cylinder 453. The flap 452 is comprised of a panel a and a panel B perpendicular to each other and joined at the sides, and the flap 452 is disposed at the corner notch and fixedly connected to the pivot 451 at the upper end of the panel a. The cylinder body of the discharging hydraulic cylinder 453 is hinged to the lower end of the second wall 412, and the piston rod of the discharging hydraulic cylinder 453 extends and retracts to drive the rotating shaft 451 to rotate, so that the folding plate 452 is driven to rotate around the rotating shaft 451, and the folding plate 452 is switched between a filling state and a discharging state. When flap 452 is in the filled condition, the surface of panel A within the compression chamber is flush with the surface of third wall 413 within the compression chamber, and the surface of panel B within the compression chamber is flush with the surface of bottom wall 415 of housing 41 within the compression chamber. When flap 452 is in the discharge position, panel a is inclined outwardly of the compression chamber and panel B is inclined toward the upper end of the compression chamber.

The metal smelting feeding assembly comprises a main frame 51, a vertical elevator 52, a smelting furnace component, a trolley component, a feeding butt joint mechanism, a negative pressure dust removal mechanism and a material conveying mechanism.

The main frame 51 is sequentially provided with a first layer bottom plate 511 and a second layer bottom plate 512 from bottom to top, a first layer space is formed between the first layer bottom plate 511 and the second layer bottom plate 512, a second layer space is formed at the upper end of the second layer bottom plate 512, and a communication port 513 for communicating the first layer space with the second layer space is formed in the second layer bottom plate 512.

The vertical lift 52 is fixedly installed on the overall frame 51 between the first floor space and the second floor space. The vertical hoist 52 includes a hoistway, a lifting table, a traction drive (not shown in the figure), and a conveyor mechanism. The lower end of the elevator shaft is provided with a material inlet 521 communicated to the first-layer space, and the upper end of the elevator shaft is provided with a material outlet 522 communicated to the second-layer space. The lifting platform is installed in the elevator shaft through a traction driving device and does lifting motion in the vertical direction. The conveying belt mechanism is arranged on the lifting platform, is provided with a conveying belt, and moves up and down synchronously along with the lifting platform so as to move between an upper butt joint position and a lower butt joint position. When the conveyor mechanism is in the upper docked position, the conveyor belt faces the material outlet 522 for outputting material, and when the conveyor mechanism is in the lower docked position, the conveyor belt faces the material inlet 521 for receiving material.

The melter assembly includes a tipping platform 531, a melter 532, and a tilt cylinder 533. The tilting platform 531 is hinged to the communication port 513 of the second floor 512 and rotates around the hinge in a vertical plane. The smelting furnace 532 is internally provided with a smelting cavity, the upper end of the smelting furnace 532 is provided with a feeding port 5321 communicated to the smelting cavity and a drainage groove 5322 communicated to the feeding port 5321, and the upper end of the outer wall of the smelting furnace 532 is fixedly connected with the tilting platform 531, is positioned at the communication port 513 of the second floor 512 and is positioned between the first floor space and the second floor space. The turning hydraulic cylinder 533 is arranged between the floor 511 and the smelting furnace 532, the lower end of the turning hydraulic cylinder is hinged to the floor 511, the upper end of the turning hydraulic cylinder is hinged to the lower surface of the turning platform 531, and the turning hydraulic cylinder is used for driving the turning platform 531 to rotate around the hinged position of the turning hydraulic cylinder, so that the smelting furnace 532 is driven to rotate, and the smelting furnace 532 is switched between a working state and a material pouring state. The smelting furnace 532 is vertical in working condition, and the feeding port 5321 is vertically upward. The smelting furnace 532 is in an inclined posture in a material pouring state, and smelting liquid in a smelting cavity can be poured out through the feeding port 5321 and the drainage groove 5322.

Carriage assembly includes guide 541 and carriage 542. The number of the guide rails 541 is two, and the two guide rails 541 are arranged in parallel and fixedly installed on the second floor 512 and distributed at two sides of the feeding port 5321 of the smelting furnace 532. Both of the guide rails are arranged perpendicular to the flow-guiding trough 5322 of the smelting furnace 532, with one guide rail 541 relatively close to the flow-guiding trough 5322 and the other guide rail relatively far from the flow-guiding trough 5322. Cart 542 includes a cart body 5421 and motorized wheels 5422. The vehicle body 5421 is provided with a hollow hole a and a hollow hole B. Electric wheels 5422 are mounted on the lower end of vehicle body 5421. The cart 542 is movably mounted on two rails 541 by electric wheels 5422.

The feeding and docking mechanism comprises an outer funnel 551, an inner funnel 552 and a traveling crane (not shown in the figure). The outer funnel 551 is fixedly installed in the hollow hole a of the vehicle body 5421, and has a bell mouth shape with a large top and a small bottom. The inner funnel 552 is in a bell mouth shape with a large upper part and a small lower part, is matched with the inner hole shape of the outer funnel 551, and is provided with a hanging lug 5521 for butting and hanging at the upper end. The traveling crane is installed in the double space, and is used for controlling the movement of the inner funnel 552, thereby docking or undocking the inner funnel 552 with the outer funnel 551. When the inner funnel 552 is docked with the outer funnel 551, the lower port of the inner funnel 552 extends into the melting chamber of the melting furnace 532 through the feed opening 5321 of the melting furnace 532.

The negative pressure dust removing mechanism comprises an electric push rod A561, a connecting frame 562, a dust collecting cover 563 and a negative pressure dust remover (not shown in the figure). The electric push rod A561 is fixedly installed on the cart body 5421 of the cart 542, and is fixedly connected with the dust collection cover 563 through the connecting frame 562 so as to drive the dust collection cover 563 to vertically move. The dust hood 563 is internally provided with a gas path channel, the gas path channel forms a dust collecting opening and a dust discharging opening at two ends of the dust hood 563, the dust hood 563 is located in the hollow hole B of the trolley 542, and the dust discharging opening and the dust collecting opening thereon are located at the upper end and the lower end of the hollow hole B respectively. The negative pressure dust remover is provided with an air inlet and an air outlet, a filter element is arranged inside the negative pressure dust remover, and the air inlet of the negative pressure dust remover is connected with a dust discharge port of the dust hood 563 through an air pipe.

The material conveying mechanism comprises a stand 571, a belt conveyor a, an upper pulling assembly and a lower support member 574. The support 571 is fixedly installed in the two-layer space. The belt conveyor a includes a rack a5721 and a conveyor belt a5722 mounted on the rack a 5721. The two ends of the belt conveyor A along the conveying direction of the conveying belt A5722 are respectively provided with a feeding end A and a discharging end A. The shelf body A5721 is sequentially provided with a first hinge joint 57211, a second hinge joint 57212 and a third hinge joint 57213 from one end to the other end, the shelf body A5721 is hinged and installed on the support 571 through the first hinge joint 57211, and the rotating path of the belt conveyor A around the first hinge joint 57211 is positioned in a vertical plane. The upper pulling assembly includes a connecting frame 5731, a wire rope 5732 and a hoist 5733. The lower end of the link 5731 is hinged to the third hinge 57213 of the frame body A5721. The lower end of the wire rope 5732 is connected to the upper end of the connecting bracket 5731, and the upper end of the wire rope 5732 is wound around the hoist 5733. The winch 5733 is fixedly installed on the support 571, the winch 5733 drives the belt conveyor a to rotate around the first hinge joint 57211 through the winding and unwinding steel cable 5732, so that the belt conveyor a is switched between a conveying state and an avoiding state, the feeding end a of the belt conveyor a is close to and opposite to the material outlet 522 of the vertical elevator 52 in the conveying state, and the discharging end a is positioned right above the feeding port 5321 of the smelting furnace 532, so as to realize the conveying of the material. In the escape state, the belt conveyor a avoids the ascending and descending movement path of the inner hopper 552, the turning path of the melting furnace 532, and the turning path of the tilting platform 531. The lower supporting member 574 is disposed between the floor panel 512 and the frame body a5721, and has an upper end hinged to the second hinge 57212 of the frame body a5721 and a lower end suspended, which is always vertical along with the rotation of the belt conveyor a. When the belt conveyor a is in a conveying state, the lower end of the lower support member 574 abuts the two-layer bottom plate 512, thereby providing support for the belt conveyor a.

The pelletizing equipment assembly includes a centrifugal atomizing pelletizing machine 6, a vibrating screening machine 64 and a heat treatment furnace 65. The centrifugal atomizing pill making machine 6, the vibratory screening machine 64 and the heat treatment furnace 65 are used in sequence in the steel shot preparation process. The centrifugal atomizing pill making machine comprises a shell 61, a motor B62 and a turntable 63. The shell 61 is provided with a pill making cavity inside, and the upper end is provided with a bell mouth 611 communicated with the pill making cavity. The motor B62 is fixedly mounted at the bottom of the pelleting chamber of the housing 61 with its shaft extending vertically upward. The center of the upper surface of the turntable 63 is provided with a pit 631 and a plurality of molten steel flowing grooves 632 radially distributed around the center of the pit 631, and two ends of the molten steel flowing grooves 632 are respectively communicated to the edge of the turntable 63 and the edge of the pit 631. The turntable is fixedly connected with the crankshaft of the motor 62 at the center of the lower end, and the concave pit of the turntable 63 is positioned right below the bell mouth 611.

Preferably, it further comprises belt conveyor B6, belt conveyor C7, and belt conveyor D8. A belt conveyor B6 is provided between the metal cutter 2 and the metal shredder 3 for conveying the material processed by the metal cutter 2 to the metal shredder 3. A belt conveyor C7 is provided between the metal shredder 3 and the metal baler 4 for conveying the material treated by the metal shredder 3 to the metal baler 4. A belt conveyor D8 is provided between the inlet and outlet of the metal baler 4 and the material inlet 521 of the vertical lift 52 for conveying the material processed by the metal baler 4 into the vertical lift 52.

Preferably, it also comprises an industrial robot arm (not shown in the figures). The industrial robot arm is used to grip and control the movement of the lance 11.

Preferably, the cart assembly further comprises a universal ball seat 543 and a steel ball 544. The lower end of the universal ball seat 543 is fixedly mounted on the second floor 512 or the tipping platform 531 and is located at the outer side of a guide rail 541 relatively close to the drainage groove 5322, a spherical pit for accommodating a steel ball is arranged at the upper end of the universal ball seat 543, and the steel ball 544 is movably mounted in the spherical pit of the universal ball seat 543; there are a plurality of universal ball seats 543, and all of the universal ball seats 543 are arranged at intervals and arranged in a row parallel to the guide rails 541. When trolley 542 moves to any position along guide 541, at least one steel ball 544 on universal ball seat 543 contacts the lower surface of body 5421 of trolley 542. Correspondingly, the cart body 5421 of the cart 542 is a rectangular frame with four top corners, the electric wheels 5422 are only arranged at the three top corners of the lower end of the cart body 5421, and the electric wheels 5422 are not arranged at the lower end of the cart body 5421 relatively close to one top corner of the drainage groove 5322.

Preferably, the trolley assembly further comprises a power push rod B545 and a positioning sleeve 546. The electric push rod B545 is fixedly connected to one end of the body 5421 of the cart 542 and vertically moves up and down. A locator sleeve 546 is fixedly mounted to the tilt platform 531 and is located at the lower end of the power push bar B545. When the trolley 542 is located at the first position, the electric push rod B545 is opposite to the positioning sleeve 546 in the up-and-down direction, and the electric push rod B545 extends into the inner hole of the positioning sleeve 546 to lock the position of the trolley 542.

Preferably, when the inner funnel 552 is butted against the outer funnel 551, the distance between the lower port of the inner funnel 552 and the bottom surface of the smelting chamber of the smelting furnace 532 is 0-5 cm. A disposable soft pad (not shown) is disposed in the lower end of the inner funnel 552, and the soft pad can be dissolved by itself at high temperature (200 ℃. & 500 ℃).

Preferably, all of the gas lines are provided with valves (not shown).

Preferably, the upper end of a steel shot inlet E1511 of the refuelling bin 151 is connected with a material receiving funnel 1513 with an electric control valve C.

Preferably, the steel shot outlet D1411 of the steel shot cleaning machine 14 is semicircular and is arranged close to the lower end edge of the end surface of the outer cylinder body 141; accordingly, the cover plate 1416 presents a semicircular shape matching the shape of the steel shot outlet D1411; correspondingly, a dry ice inlet 1412, an exhaust gas outlet 1413 and a steel shot inlet D1414 are all positioned at the upper end of the end surface of the outer cylinder body 141.

Preferably, the high pressure air source 17 is an air compressor.

Preferably, the negative pressure pumping device 18 is a vacuum pump.

The state of the trolley is described as follows:

the carriage 542 is provided with a first position, a second position, and a third position in this order along the moving path of the guide rail 541. When the trolley 542 is in the first position, the lower end opening of the outer funnel 551 is directly above and below the feed opening 5321 of the smelting furnace 532 in operation. When the trolley 542 is in the second position, the dust collection port of the dust collection hood 563 faces up and down the feed port 5321 of the operating melting furnace 532. When cart 542 is in the third position, cart 542 is offset up and down from the path of rotation of dump platform 531. Outer funnel 551 may be docked or undocked from inner funnel 552 only when cart 542 is in the first position.

The working principle of the shot blasting decontamination device is as follows:

the operator remotely controls the industrial robot arm to operate to grip the spray gun 11 and control the spray gun 11 to move, to face and abut the blasting operation port 1111 of the spray gun 11 against the surface of the nuclear waste metal, and then to activate the high-pressure air source 17 and the negative-pressure air suction device 18. Under the combined action of the high-pressure air source 17 and the negative-pressure air extraction device 18, the steel shots are circulated among the spray gun 111, the screening bin 121 and the recovery bin 122.

When the steel shot flows through the lance 11, the moving path is a steel shot injection passage 112, a confluence chamber 111, and a steel shot recovery passage 113 in this order. After entering the converging cavity 111, the steel shots move towards the shot blasting operation opening 1111 and finally impact the metal surface, so that on one hand, stains, rust and radioactive substance layers on the metal surface are peeled off, on the other hand, the steel shots immediately rebound and change direction, and enter the steel shot recovery channel 113 under the action of negative pressure.

After the high-pressure air source 17 is started, the air is blown into the screening bin 121 from bottom to top through the air blowing port A1213, so that impurities, dust and debris in the screening bin 121 are blown to the upper area of the screening bin 121.

After the high-pressure air source 18 is started, air is blown into the shot injection channel 112 of the spray gun 11 through the three-way joint 123 and the shot inlet a1121, so that a shot outlet C1221 connected to the three-way joint 123 generates negative pressure, and under the action of the negative pressure, the shots are discharged from the shot outlet C1221 of the recovery bin 122 and then enter the air path pipeline, and then flow into the shot injection channel 112 of the spray gun 11 under the pushing of wind power.

After the negative pressure air extraction device 19 is started, negative pressure is generated in the upper cavity 1311 of the dust collection bin 131, the lower cavity 1312 of the dust collection bin 131, the upper area of the screening bin 121 and the steel shot recovery channel 113 of the spray gun 11 in sequence. Under the action of the negative pressure, impurities, dust and debris in the upper region of the screening chamber enter the lower chamber 1312 of the dust collecting chamber 131, and then settle at the bottom of the lower chamber 1312 or are collected by the filter element 132.

In the method, the valves on the air path pipelines which are not involved are in a closed state, and the valves on the air path pipelines which are involved are in an open state.

The working principle of the metal compression packer is as follows:

after the crushed metal materials enter the compression cavity of the box body 41 through the material inlet and outlet at the upper end of the box body 41, the turning hydraulic cylinder 442 is started to drive the turning plate 441 to rotate around the fourth hinge joint 4411 in a vertical plane, so that the material inlet and outlet of the box body 41 are sealed on one hand, and the crushed metal materials in the compression cavity of the box body 41 are compressed in the height direction on the other hand.

Then, the X-direction hydraulic cylinder 421 is activated to drive the X-direction push plate 422 to move in a direction close to the second wall 412, so as to compress the metal particles in the compression cavity in the horizontal X-direction (the moving direction of the X-direction push plate 422 is defined as the X-direction), and when the X-direction push plate 422 moves to be flush with the side edge of the rectangular opening a, the movement is stopped.

Then, the Y-direction hydraulic cylinder 431 is actuated to drive the Y-direction push plate 432 to move in a direction to approach the third wall 413, and the crushed metal in the compression chamber is compressed in the horizontal Y-direction (the moving direction of the Y-direction push plate 432 is defined as the Y-direction), so that a rectangular parallelepiped block is formed after the compression of the crushed metal is completed.

Then, the X-direction hydraulic cylinder 421 and the Y-direction hydraulic cylinder 431 are respectively driven to retract the X-direction push plate 422 and the Y-direction push plate 432 to the original position without being sequentially started. Finally, the discharging hydraulic cylinder 453 is actuated to rotate the flap 452 via the shaft 451, so that the flap 452 is rotated from the filled state to the discharged state, and the compressed rectangular parallelepiped block is tilted and discharged from the compression chamber of the case 41.

A preparation method of the special steel shot for removing the radioactivity of the nuclear waste metal is applied to the preparation system of the special steel shot for removing the radioactivity of the nuclear waste metal. Before preparing the steel shots, the special steel shot preparation system for removing the radioactivity of the nuclear waste metal is in an initial state, and in the initial state:

a. steel shots in the shot blasting decontamination device 1 are collected in the screening bin 121;

b. the feed and discharge ports of the case 41 are open;

c. the X-direction push plate 422 is flush with the rectangular opening B;

d. the Y-direction push plate 432 is flush with the rectangular opening A;

e. flap 452 is in a filled state;

f. the smelting furnace 532 is in a working state;

g. cart 542 is in the first position;

h. inner funnel 552 interfaces with outer funnel 551;

i. the belt conveyor A is in a conveying state;

j. the electric push rod B545 extends into the inner hole of the positioning sleeve 546;

k. the dial 63 is in a rotated state.

The preparation method of the steel shot comprises the following steps:

s01, surface shot blasting:

a. aiming at the nuclear waste metal with the inner wall surface, cutting treatment is carried out through a metal cutting machine 2, so that the inner wall surface is exposed, and surface shot blasting is conveniently carried out subsequently;

b. the operator remotely controls the industrial robot arm to operate to grip the spray gun 11 and control the spray gun 11 to move, to face and abut the blasting operation port 1111 of the spray gun 11 against the surface of the nuclear waste metal, and then to activate the high-pressure air source 17 and the negative-pressure air suction device 18. Under the combined action of the high-pressure air source 17 and the negative-pressure air extraction device 18, the steel shots are circulated among the spray gun 111, the screening bin 121 and the recovery bin 122.

In this step, when the steel shot flows through the lance 11, the moving path is the steel shot injection passage 112, the converging chamber 111, and the steel shot recovery passage 113 in this order. After entering the converging cavity 111, the steel shots move towards the shot blasting operation opening 1111 and finally impact the metal surface, so that on one hand, stains, rust and radioactive substance layers on the metal surface are peeled off, on the other hand, the steel shots immediately rebound and change direction, and enter the steel shot recovery channel 113 under the action of negative pressure.

In this step, after the high-pressure air source 17 is started, the air is blown into the screening bin 121 from bottom to top through the air blowing port a1213, so as to blow impurities, dust and debris in the screening bin 121 to the upper region of the screening bin 121.

In this step, after the high-pressure air source 17 is started, air is blown into the shot injecting passage 112 of the spray gun 11 through the three-way joint 123 and the shot inlet a1121, so that the shot outlet C1221 connected to the three-way joint 123 generates negative pressure, and under the action of the negative pressure, the shots are discharged from the shot outlet C1221 of the recovery bin 122, then enter the air path pipeline, and flow into the shot injecting passage 112 of the spray gun 11 under the pushing of wind power.

In this step, after the negative pressure air extraction device 18 is started, negative pressure is sequentially generated in the upper chamber 1311 of the dust collection bin 131, the lower chamber 1312 of the dust collection bin 131, the upper region of the screening bin 121, and the shot recycling channel 113 of the spray gun 11. Under the action of the negative pressure, impurities, dust and debris in the upper region of the screening chamber enter the lower chamber 1312 of the dust collecting chamber 131, and then settle at the bottom of the lower chamber 1312 or are collected by the filter element 132.

S02, fragmenting:

cutting the nuclear waste metal subjected to surface shot blasting into the size meeting the feeding requirement of the metal shredder 3 by a metal cutting machine; and putting the cut nuclear waste metal into a metal shredder 3 for shredding.

S03, compression and packaging:

a. after the crushed metal materials formed by shredding are transferred into a compression cavity of the box body 41, the turning hydraulic cylinder 442 is started to drive the rotating plate 441 to rotate around the fourth hinge joint 4411 in a vertical plane, so that on one hand, a material inlet and a material outlet of the box body 41 are sealed, and on the other hand, the crushed metal materials in the compression cavity of the box body 41 are compressed in the height direction;

b. the X-direction hydraulic cylinder 421 is started to drive the X-direction push plate 422 to move towards the direction close to the second wall 412, the metal particles in the compression cavity are compressed in the horizontal X direction (the moving direction of the X-direction push plate 422 is defined as the X direction), and when the X-direction push plate 422 moves to be flush with the side edge of the rectangular opening A (the side edge is the side edge of the rectangular opening A relatively far away from the second wall 412), the movement is stopped;

c. the Y-direction hydraulic cylinder 431 is started to drive the Y-direction push plate 432 to move towards the direction close to the third wall 413, metal particles in the compression cavity are compressed in the horizontal Y direction (the moving direction of the Y-direction push plate 432 is defined as the Y direction), and a cuboid block, which is hereinafter referred to as a metal block, is formed after the metal particles are compressed;

d. the X-direction hydraulic cylinder 421 and the Y-direction hydraulic cylinder 431 are started in sequence, and the X-direction push plates 422 and the Y-direction push plates 432 are respectively driven to return to the original positions;

e. the discharging hydraulic cylinder 453 is started to drive the flap 452 to rotate through the rotating shaft 451, so that the flap 452 rotates from the vacancy state to the discharging state, and the compressed cuboid blocks are tilted and discharged from the compression cavity of the box body 41.

S04, feeding in a cooling furnace:

a. the metal blocks are sent into the vertical lifter 52 through the material inlet 521, and after the vertical lifter 52 lifts the metal blocks from the first-layer space to the second-layer space, the metal blocks are driven to be discharged out of the vertical lifter 52 through the material outlet 522;

b. after being discharged from the material outlet 522, the metal blocks enter the conveying belt A5722 through the feeding end A of the belt conveyor A, and move to the discharging end A of the belt conveyor A along with the conveying belt A5722;

c. after being discharged from the discharge end a of the belt conveyor a, the metal blocks enter a smelting cavity of the smelting furnace 532 through an inner funnel 552;

d. after the feeding is finished, the winch 5733 is started to pull the belt conveyor A to rotate upwards around the first hinge joint 57211, so that the belt conveyor A is changed from a conveying state to an avoiding state;

e. the hanging hook at the lower end of the traveling crane hooks the hanging lug at the upper end of the inner funnel 552, and the traveling crane is operated to lift the inner funnel 552 upwards, so that the inner funnel 552 is completely separated from the outer funnel 551.

In the step, when the inner funnel is butted with the outer funnel, the distance between the lower port of the inner funnel and the bottom surface of a smelting cavity of the smelting furnace is 0-5 cm; be provided with disposable cushion in the lower port of interior funnel, the cushion plays the cushioning effect, can avoid the smelting chamber bottom surface of smelting furnace to be injured by the metal block pounding.

S05, smelting metal:

a. the electric push rod B545 exits the inner hole of the positioning sleeve 546 to release the position locking of the trolley 542, and then the trolley 542 moves from the first position to the second position, so that the dust collecting port of the dust collecting hood 563 is opposite to the feeding port 5321 of the smelting furnace 532;

b. starting the heating function of the smelting furnace to smelt the metal blocks; in the smelting process, on one hand, the continuous operation of the negative pressure dust collector is ensured, so that the volatile gas generated by smelting enters the negative pressure dust collector through the dust collection cover 563, the radioactive nuclide in the gas is intercepted in a filter element of the negative pressure dust collector, the filtered gas is discharged to the atmosphere through the negative pressure dust collector, and on the other hand, the slag generated by smelting is manually cleaned in real time;

c. after smelting is completed, the driving trolley moves from the second position to the third position, so that the rotating paths of the trolley 542 and the tipping platform 531 are staggered up and down.

In this step, during the smelting process, there is a height difference between the dust hood 563 and the material inlet 5321 to facilitate observation of the conditions inside the smelting furnace 532, and if the smelting liquid crusts, manual intervention is immediately performed to avoid frying the furnace.

S06, preparing steel shots:

a. controlling the turning hydraulic cylinder 533 to act, so that the smelting liquid in the smelting furnace is discharged through the feeding port 5321 and the drainage groove 5322 in sequence, enters the pill making cavity of the shell 61 through the bell mouth 611, falls into the pit 631 of the rotating turntable 63, is thrown out through the molten steel flowing groove 632 under the action of centrifugal force to form molten steel droplets, and falls into cooling water at the lower part of the pill making cavity of the shell 61 to form steel pills;

In the step, the steel shots with the diameter less than 0.25mm and the diameter more than 2mm are sent back to the smelting furnace for smelting again.

A steel shot cleaning method is applied to the shot blasting decontamination device and is used for removing radioactive nuclides stained on the surface of the steel shot. Before the cleaning method is executed, the shot blasting apparatus 1 is in the following state:

1. the outer cylinder 141 rotates until the steel shot outlet D1411 faces obliquely upward;

2. the electric control valve A on the steel shot dropping port 1214 of the screening bin 121 is closed;

3. an electric control valve D on a steel shot outlet B1215 of the screening bin 121 is closed;

4. closing the electric control valve B on the slag discharge port 1415 of the steel shot cleaning machine 14;

5. an electric control valve C on the receiving hopper 1513 of the shot dispatcher 15 is opened.

The cleaning method comprises the following steps:

s01, collecting the steel shots in a screening bin:

an operator remotely controls the industrial mechanical arm to act so as to hold the spray gun 11 and move the spray gun 11, and the shot blasting operation port 1111 of the spray gun 11 is opposite to and abutted against a plane, so that the shot blasting operation port 1111 is closed; then starting the high-pressure air source 17 and the negative-pressure air extraction device 18 to enable the steel shots to flow along the flow path of the recovery bin 122, the spray gun 11 and the screening bin 121 and to be completely collected into the screening bin 121, and then closing the high-pressure air source 17 and the negative-pressure air extraction device 18.

In this step, after the negative pressure air extraction device 18 is started, negative pressure is sequentially generated in the upper chamber 1311 of the dust collection bin 131, the lower chamber 1312 of the dust collection bin 131, the upper region of the screening bin 121, and the shot recycling channel 113 of the spray gun 11.

In this step, after the high-pressure air source 18 is started, air is blown into the shot injection channel 1112 of the spray gun 11 through the three-way joint 123 and the shot inlet a1121, so that the shot outlet C1221 connected to the three-way joint 123 generates negative pressure, and under the action of the negative pressure, the shots are discharged from the shot outlet C1221 of the recovery bin 122, then enter the air path pipeline, and then flow into the shot injection channel 112 of the spray gun 11 under the pushing of wind power.

In this step, when the steel shot flows through the lance 11, the moving path is the steel shot injection passage 112, the converging chamber 111, and the steel shot recovery passage 113 in this order. After entering the converging chamber 111, the steel shots move towards the shot blasting operation port 1111 and finally impact the metal surface, and when the steel shots impact the plane, the steel shots rebound and change direction immediately and enter the steel shot recovery channel 113 under the action of negative pressure.

S02, conveying the steel shots into a steel shot cleaning machine:

an electrically controlled valve D on a steel shot outlet B1215 of the screening bin 121 is opened, so that the steel shots in the screening bin 121 enter the inner cavity of the inner cylinder 142 through a steel shot inlet D1414 on the outer cylinder 141.

In this step, since the screening bin 121 is located above the shot washer 14, the shot can naturally flow by its own gravity.

S03, cleaning steel shots:

a. dry ice pellets are thrown into the dry ice storage chamber of the dry ice supply device 16 through the dry ice dispensing opening 162, and then the following three operations are simultaneously performed:

1. the motor 145 is started, the inner cylinder 142 is driven to rotate circularly relative to the outer cylinder 141, the steel shots in the inner cavity of the inner cylinder 142 are enabled to roll fully, on one hand, all surfaces of the steel shots have the chance of contacting dry ice particles, on the other hand, small parts of radioactive nuclides on the surfaces of the steel shots are stripped through the mutual collision action among the steel shots, and the scraps generated by collision enter the annular cavity 146 through the hollow holes 1421 and are collected at the lowest position of the annular cavity 146;

2. starting the high-pressure air source 17, so that the dry ice particles in the dry ice storage cavity sequentially pass through the dry ice output port 163 of the dry ice supply device and the dry ice inlet 1412 of the outer cylinder body 141 and enter the inner cavity of the inner cylinder body 142; after entering the inner cavity of the inner cylinder 142, the dry ice particles directly impact the surface of the steel shot, and most of radioactive nuclides on the surface of the steel shot are stripped through sublimation;

3. starting the negative pressure air extraction equipment 18 to enable the upper cavity 1311 of the dust collection bin 131, the lower cavity 1312 of the dust collection bin 131 and the inner cavity of the inner barrel 142 to generate negative pressure in sequence; under the action of negative pressure, the gas containing the radionuclide in the inner cavity of the inner cylinder 142 sequentially passes through the waste gas outlet 1413 of the outer cylinder 141, the sand and dust inlet 1313 of the dust collection bin 131, the lower cavity 1312 of the dust collection bin 131, the filter element 132, the upper cavity 1311 of the dust collection bin 131 and the negative pressure air extraction device 18, and is discharged to the outside. In the process, when the gas flows through the filter element 132, the radioactive nuclide is retained in the filter element 132, so that the gas finally discharged to the outside is ensured to be pollution-free gas;

b. after the steel shots are cleaned, the high-pressure air source 17, the negative-pressure air extraction device 18 and the motor 145 are closed, and the electric control valve B on the slag discharge port 1415 of the outer cylinder body 141 is opened, so that the scraps in the annular cavity 146 are discharged.

In this step, the dry ice particles are cylindrical, with a diameter of 3mm and a length of 5.5 mm.

S04, conveying the steel shots into a recovery bin:

a. the electric push rod X144 acts to enable the outer cylinder body 141 to rotate around the hinged position of the outer cylinder body to form a vertical plane, when the outer cylinder body 141 rotates until the steel shot outlet D1414 faces to the inclined lower side, the cover plate 1416 rotates under the self-weight, and steel shots in the inner cavity of the inner cylinder body 142 are discharged through the steel shot outlet D1414;

b. the steel shots are discharged and then fall freely, and enter the refuge bin 151 through a steel shot inlet E1511;

c. the electric push rod Y153 is started to drive the dispatch and return bin 151 to rotate around the hinged position of the dispatch and return bin 151 in a vertical plane, when the dispatch and return bin 151 rotates until the steel shot outlet E1521 faces obliquely downwards, the negative pressure air extraction equipment 18 is started to enable the recovery bin 122 and the dispatch and return bin 151 to generate negative pressure in sequence, and under the action of the negative pressure, the steel shots in the dispatch and return bin 151 sequentially pass through the steel shot outlet E1521 of the dispatch and return bin 151 and the steel shot dispatch and return port 1223 of the recovery bin 122 to enter the recovery bin 122.

Claims

1. The preparation method of the special steel shot for removing the radioactivity of the nuclear waste metal is characterized by being applied to a preparation system of the special steel shot for metal nuclear decontamination, and used for preparing the steel shot;

the preparation system of the special steel shot for metal nuclear decontamination comprises a shot blasting decontamination device, a metal cutting machine, a metal shredder, a metal compression packer, a metal smelting feeding assembly and a shot making equipment assembly;

b. the feed and discharge port of the box body is opened;

c. the X-direction push plate is flush with the rectangular opening B;

d. the Y-direction push plate is flush with the rectangular opening A;

e. the folded plate is in a gap filling state;

f. the smelting furnace is in a working state;

g. the trolley is in a first position;

h. the inner funnel is butted with the outer funnel;

i. the belt conveyor A is in a conveying state;

k. the turntable is in a rotating state;

the preparation method of the steel shot comprises the following steps:

s01, surface shot blasting:

when the steel shots flow through the spray gun, the moving path sequentially comprises a steel shot injection channel, a converging cavity and a steel shot recycling channel; after entering the converging cavity, the steel shots move towards the shot blasting operation opening and finally impact the metal surface, so that on one hand, stains, rust and radioactive substance layers on the metal surface are stripped, on the other hand, the steel shots rebound and change directions immediately and enter a steel shot recovery channel under the action of negative pressure;

after a high-pressure air source is started, blowing air from bottom to top into the screening bin through a blast port A to blow impurities, dust and fragments in the screening bin to an upper area of the screening bin;

after a high-pressure air source is started, blowing air into a shot injection channel of the spray gun through a three-way joint and a shot inlet A to enable a shot outlet C connected to the three-way joint to generate negative pressure, discharging the shots from the shot outlet C of the recovery bin under the action of the negative pressure, then enabling the shots to enter a gas path pipeline, and then enabling the shots to flow into the shot injection channel of the spray gun under the pushing of wind power;

after the negative pressure air extraction equipment is started, negative pressure is generated in the upper cavity of the dust collection bin, the lower cavity of the dust collection bin, the upper area of the screening bin and the steel shot recovery channel of the spray gun in sequence; under the action of negative pressure, impurities, dust and debris in the upper area of the screening bin enter the lower cavity of the dust collecting bin, so that the impurities, the dust and the debris are settled at the bottom of the lower cavity or are collected by the filter element;

s02, fragmenting:

s03, compression and packaging:

s04, feeding in a cooling furnace:

s05, smelting metal:

s06, preparing steel shots:

a. controlling the turning hydraulic cylinder to act, so that the smelting liquid is discharged through the feeding port and the drainage groove in sequence, enters the pelleting cavity of the shell through the bell mouth, falls into a pit of the rotating turntable, is thrown out through the molten steel flowing groove under the action of centrifugal force to form molten steel droplets, falls into cooling water at the lower part of the pelleting cavity of the shell to form steel shots, and the steel shots are used for surface shot blasting in the step S01;

2. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 1, which is characterized in that: when the shot blasting decontamination device continuously operates for 4-10min, starting a steel shot decontamination process to remove the radioactive nuclides stained on the surface of the steel shot; before the cleaning process is executed, the shot blasting decontamination device is in the following state:

the steel shot decontamination process comprises the following steps:

s01, collecting the steel shots in a screening bin:

s02, conveying the steel shots into a steel shot cleaning machine:

s03, cleaning steel shots:

s04, conveying the steel shots into a recovery bin:

3. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 2, which is characterized in that: in step S03 of the steel shot decontamination procedure, the dry ice particles were cylindrical in shape, with a diameter of 3mm and a length of 5.5 mm.

4. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 3, which is characterized in that: in step S06 of the steel shot preparation method, the steel shots with the diameter less than 0.25mm and the diameter more than 2mm are sent back to the smelting furnace for smelting again.

5. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 4, which is characterized in that: in the step S04 of the steel shot preparation method, when the inner funnel is butted with the outer funnel, the distance between the lower port of the inner funnel and the bottom surface of a smelting cavity of the smelting furnace is 0-5 cm; be provided with disposable cushion in the lower port of interior funnel, the cushion plays the cushioning effect, can avoid the smelting chamber bottom surface of smelting furnace to be injured by the metal block pounding.

6. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 4 or 5, characterized in that: in the step S05 of the steel shot preparation method, in the smelting process, the height difference exists between the dust-collecting hood and the feeding port, so that the condition in the smelting furnace can be observed conveniently, and if the smelting liquid crusts, manual intervention is immediately carried out, so that the furnace is prevented from being exploded.

7. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 6, which is characterized in that: in the S01 step of the steel shot preparing method and the S01 step of the steel shot decontamination process, the operator remotely controls the industrial robot arm to operate to grip the spray gun and control the spray gun to move.

8. The method for preparing special steel shots for removing radioactivity of nuclear waste metals according to claim 7, which is characterized in that: the trolley assembly further comprises a universal ball seat and a steel ball, the lower end of the universal ball seat is fixedly arranged on the second floor or the tipping platform and is positioned on the outer side of a guide rail relatively close to the drainage groove, a spherical pit for containing the steel ball is formed in the upper end of the universal ball seat, and the steel ball is movably arranged in the spherical pit of the universal ball seat; the universal ball seats are arranged at intervals and are arranged in a row parallel to the guide rail; when the trolley moves to any position along the guide rail, at least one steel ball on the universal ball seat is contacted with the lower surface of the trolley body; correspondingly, the trolley body of the trolley is a rectangular frame with four vertex angles, the electric wheels are only arranged at the three vertex angles at the lower end of the trolley body, and the electric wheels are not arranged at the lower end of one vertex angle of the trolley body, which is relatively close to the drainage groove; in the moving process of the trolley, the trolley is supported by the steel balls, so that the stability of the trolley in the moving process is ensured.