A solidified substrate casing round polishing machine for nuclear waste vitrification

Abstract

A solidified substrate sleeve-type rounding machine for vitrification of nuclear waste includes a furnace body with a hot environment inside, an outer cylinder and an inner cylinder that can rotate concentrically at a uniform speed are arranged inside the furnace body, a feed port is arranged at the same end of the outer cylinder and the inner cylinder, and a discharge port is arranged at the other end, and the feed port of the outer cylinder and the inner cylinder are arranged slightly higher than the discharge port; the thermal environment temperature in the furnace body is distributed in a mountain shape or a trapezoidal shape along the axial direction of the outer cylinder and the inner cylinder. The present invention increases the working area of ​​the glass ball rotation and flipping, heats more evenly, improves the rounding efficiency, and improves the production capacity of a single machine; the thermal space inside the outer cylinder is fully utilized, which improves the thermal efficiency of the rounding machine; the heat receiving plate on the outer peripheral wall of the inner cylinder not only increases the heat transfer area, has a higher heat transfer efficiency, but also reduces the escape of hot air.

Description

Technical Field

[0001] The invention belongs to the technical field of radioactive waste disposal, and in particular relates to a solidified substrate sleeve-type round polishing machine for vitrification of nuclear waste. Background Art

[0002] The operation of nuclear industry and nuclear power plants will inevitably produce a certain amount of radioactive waste. If it is not safely disposed of, it will pose a threat to human survival. With the help of solidification substrates, radioactive waste can be converted into a stable solid body, loaded into metal containers, and buried in underground nuclear waste storage to prevent the migration and leakage of radioactive nuclides. This deep geological disposal is currently a generally accepted solution internationally. Since the 1950s, a variety of solidification substrates have been studied to solidify radioactive waste, such as cement, asphalt, polymers, glass, artificial rocks and other substrates and radioactive waste to form a solid body.

[0003] Compared with solidifying substrates such as cement, asphalt, and polymers, heating and melting (vitrification) a glass substrate together with radioactive waste will produce a solidified body with smaller volume and more stable performance. Since the volume of the solidified body is reduced and the stability is improved, the safety of radioactive waste disposal is improved and the cost of deep geological disposal of the solidified body is reduced. Vitrification technology is currently the only industrially applied and most mature high-level liquid waste treatment technology in the world.

[0004] From the technical perspective of implementing vitrification disposal of radioactive waste, the glass substrate used must have high fluidity to ensure that the feeding system for conveying the glass substrate operates highly stably and avoids the risk of blockage; however, existing literature does not provide a production method for the relevant glass substrate.

[0005] The preparation of spherical glass substrates can prevent the risk of clogging of glass substrate feed, improve the stability of the feeding system, and meet the requirements of unpowered feeding and transportation of nuclear waste vitrification.

[0006] At present, the roundness and appearance gloss of either multi-roller ball making machines or molded glass balls cannot meet the roundness technical requirements of glass balls for nuclear waste vitrification. It is necessary to manufacture high-precision glass balls through room temperature polishing and / or heated polishing methods.

[0007] The process of finishing the shape and roundness defects of non-round glass balls is referred to as rounding process. A certain amount of isolating agent or abrasive can be mixed into the glass balls with shape and roundness defects, and then put into a rotating metal cylinder with openings at both ends. During the repeated rotation and rolling, the residual edge residue on the glass balls, the deformation caused by mold misalignment, or the roundness and appearance defects caused by pitting on the mold surface can be removed.

[0008] The rounding process is divided into normal temperature method and elevated temperature method; the normal temperature method is to put the non-round glass balls mixed with a certain amount of abrasives into a rotating metal cylinder and repeatedly turn them over to improve the roundness, but it is not smooth; the elevated temperature method, also called fire polishing, is to put the non-round glass balls mixed with a certain amount of isolation agent into a rotating metal cylinder. The metal cylinder obtains heat from the external thermal environment and radiates heat to the glass balls in the metal cylinder to ±10°C near the softening point. The glass balls become soft and after repeated turnings, their roundness and gloss are improved. However, there are certain disadvantages in the horizontal rounding by fire polishing: 1. The glass balls are easily stacked at the bottom of the metal cylinder, which not only heats unevenly, but also has a limited working area for the rotation and turning of the glass balls, and the rounding efficiency is extremely low; 2. The hot air in the cylinder quickly escapes directly from the openings at both ends, and the temperature gradient in the cylinder is difficult to establish, and "hot spots" (the highest temperature point, see Figure 2 ) is not prominent, unstable, dissipates a lot of heat, and consumes a lot of energy; 3. Because the "hot spot" is not prominent and the temperature gradient is unstable, the time to heat the glass ball to the softening point is extended; 4. Most of the space inside the metal cylinder is idle, and the production capacity of a single machine is low. Summary of the invention

[0009] In response to the current technical problems, the present invention provides a solidified substrate sleeve-type round-polishing machine for nuclear waste vitrification that meets the requirements of the roundness of the spherical glass substrate and the unpowered feeding and conveying of nuclear waste vitrification, prevents blockage in the feeding of the spherical glass substrate during vitrification, improves the stability of the feeding system, and improves the thermal efficiency of the round-polishing machine and the single-machine production capacity.

[0010] The technical solution adopted by the present invention is:

[0011] A sleeve-type circular polishing machine for solidifying substrates for vitrification of nuclear waste, characterized in that it includes a furnace body with a hot environment inside, wherein an outer cylinder and an inner cylinder that can rotate concentrically at a uniform speed are arranged in the furnace body, a feed port is arranged at the same end of the outer cylinder and the inner cylinder, and a discharge port is arranged at the other end, and the feed ports of the outer cylinder and the inner cylinder are slightly higher than the discharge port; the hot environment temperature in the furnace body is distributed in a mountain shape or a trapezoidal shape along the axial direction of the outer cylinder and the inner cylinder.

[0012] Furthermore, the outer peripheral surface of the inner cylinder is provided with a plurality of rows of heat receiving fins arranged in the radial direction.

[0013] Furthermore, the heat receiving plate is a circular ring structure.

[0014] Furthermore, the spacing between the heat receiving plates of the circular ring structure is equal or unequal.

[0015] Furthermore, the outer diameters of the heat-receiving plates of the multiple rows of the circular ring structures are equal or unequal.

[0016] Alternatively, the outer peripheral surface of the inner cylinder is provided with a spiral heating surface.

[0017] Furthermore, the pitches of the spiral heating surfaces are equal or unequal.

[0018] Alternatively, the outer peripheral surface of the inner cylinder is provided with a plurality of rows of heat receiving fins arranged along the axial direction.

[0019] Furthermore, the heat receiving plate is a rectangular structure and is radially distributed around the outer peripheral surface of the inner cylinder.

[0020] Furthermore, the outer cylinder and the inner cylinder are both connected to corresponding driving parts that drive them to rotate.

[0021] The present invention is not only used for vitrification of nuclear waste, but also can be used for glass manufacturing for other purposes, such as glass balls for liquid crystal displays, glass shot blasting or glass jewelry.

[0022] Beneficial effects of the present invention:

[0023] 1. The working area of ​​glass ball rotation and flipping is increased, the heating is more uniform, the rounding efficiency is improved, and the single machine capacity is increased;

[0024] 2. The heat space inside the outer cylinder is fully utilized, which improves the thermal efficiency of the round polishing machine;

[0025] 3. The heat receiving plate on the outer wall of the inner cylinder not only increases the heat transfer area and improves the heat transfer efficiency, but also reduces the escape of hot air;

[0026] 4. The heat receiving plates arranged with unequal spacing or pitch have different heat radiation capabilities to form temperature zones, making the "hot spots" prominent. The temperature gradient distribution in the barrel is more in line with the requirements of the rounding process.

[0027] 5. The three-dimensional diameter error of the glass ball after fire polishing is less than 10 wires, and the degree of rest is less than 3 degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention.

[0029] Figure 2 It is a temperature curve diagram of the thermal environment in the furnace body of the present invention.

[0030] Figure 3 It is a structural schematic diagram of a heat receiving plate with a circular ring structure arranged outside the inner cylinder of the present invention.

[0031] Figure 4 It is a structural schematic diagram of the present invention in which a spiral heating surface is arranged outside the inner cylinder.

[0032] Figure 5 It is a schematic structural diagram of a rectangular heat-receiving plate disposed outside the inner cylinder of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all possible alternatives, improvements and equivalents within the scope of the claims.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more, unless otherwise clearly defined.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] Embodiment 1

[0038] Reference Figure 1-3The present embodiment provides a solidified substrate sleeve-type round polishing machine for vitrification of nuclear waste, including a furnace body 3 with a hot environment inside, wherein an outer cylinder body 4 and an inner cylinder body 5 which can rotate concentrically at a uniform speed are arranged in the furnace body 3, wherein the outer cylinder body 4 and the inner cylinder body 5 are connected to corresponding driving parts which drive them to rotate, specifically, the outer cylinder body 4 is connected to a first driving part 6 which drives it to rotate, and the inner cylinder body 5 is connected to a second driving part 7 which drives it to rotate. The same end of the outer cylinder 4 and the inner cylinder 5 is provided with a feed port, specifically, the head end of the outer cylinder 4 is provided with a first feed port 2, and the head end of the inner cylinder 5 is provided with a second feed port 1; the other end of the outer cylinder 4 and the inner cylinder 5 is provided with a discharge port, specifically, the tail end of the outer cylinder 4 is provided with a first discharge port 9, and the tail end of the inner cylinder 5 is provided with a second discharge port 8; the feed ports of the outer cylinder 4 and the inner cylinder 5 are slightly higher than the discharge port, that is, the round polishing machine can be arranged with a high head and a low tail, and tilted to the tail at a small angle with the horizontal line; the thermal environment temperature in the furnace body 3 is distributed in a mountain shape or a trapezoidal shape along the axial direction of the outer cylinder 4 and the inner cylinder 5. The material of the outer cylinder 4 and the inner cylinder 5 of the present invention is heat-resistant steel. The present invention adopts a concentric metal double-cylinder structure, and it can actually be set as a multi-cylinder structure according to needs. The invention increases the working area of ​​glass ball rotation and flipping, heats more evenly, improves rounding efficiency, and improves the production capacity of a single machine; at the same time, the heat space inside the outer cylinder is fully utilized, thereby improving the thermal efficiency of the rounding machine.

[0039] The outer peripheral surface of the inner cylinder 5 described in this embodiment is provided with several rows of heat receiving plates 10 arranged in the radial direction, which not only increases the heat transfer area and has higher heat transfer efficiency, but also reduces the escape of hot air, and is more conducive to establishing and stabilizing the axial "mountain-shaped" or "trapezoidal" temperature distribution of the outer cylinder 4 and the inner cylinder 5. The heat receiving plate 10 described in this embodiment is a circular ring structure. The spacing between the heat receiving plates 10 of the circular ring structure is equal or unequal. The outer diameters of the heat receiving plates 10 of the multiple rows of the circular ring structure are equal or unequal. The heat receiving plates 10 arranged at unequal intervals have different heat radiation capabilities to form temperature partitions, so that the "hot spots" are prominent, and the temperature gradient distribution in the cylinder is more in line with the requirements of the rounding process. The material of the heat receiving plate 10 is aluminum alloy, brass, bronze or ordinary steel. In order to improve the thermal conductivity of the heat receiving plate 10, a layer of thermal conductive silicone grease can be applied on its surface to make the heat more effectively transferred to the inner cylinder 5 and then radiated to the glass ball.

[0040] The present invention is not only used for vitrification of nuclear waste, but also can be used for glass manufacturing for other purposes, such as glass balls for liquid crystal displays, glass shot blasting or glass jewelry.

[0041] When the present invention is working, the non-round glass balls enter the outer cylinder 4 and the inner cylinder 5 placed in the hot environment of the furnace body 3 from the first feed port 2 and the second feed port 1 at the head respectively, and the outer cylinder 4 and the inner cylinder 5 are driven by the first drive part 6 and the second drive part 7 to rotate concentrically at a uniform speed. The non-round glass balls continuously rotate and turn over on the inner walls of the outer cylinder 4 and the inner cylinder 5 respectively, and move along the inner walls of the outer cylinder 4 and the inner cylinder 5 to the first discharge port 9 and the second discharge port 8 at the tail in turn, and are finally discharged from the rounding machine respectively; the three-dimensional diameter error of the glass balls after fire polishing is less than 10 wires, and the rest degree is less than 3 degrees.

[0042] Embodiment 2

[0043] See also Figure 4 The difference between this embodiment and the first embodiment is that: the outer peripheral surface of the inner cylinder 5 is provided with a spiral heating surface 11. The pitch of the spiral heating surface 11 is equal or unequal. The spiral heating surfaces 11 arranged with unequal pitches have different heat radiation capabilities to form temperature zones, so that the "hot spots" are prominent, and the temperature gradient distribution in the cylinder is more in line with the requirements of the rounding process.

[0044] The material of the spiral heating surface 11 of this embodiment can also be aluminum alloy, brass, bronze or ordinary steel. In order to improve the thermal conductivity of the heating plate, a layer of thermal conductive silicone grease can be coated on its surface to make the heat more effectively transferred to the inner cylinder 5 and then radiated to the glass ball.

[0045] The remaining structures and functions may refer to those described in the first embodiment.

[0046] Embodiment 3

[0047] See also Figure 5 The difference between this embodiment and the first embodiment is that: the outer peripheral surface of the inner cylinder 5 is provided with a plurality of rows of heat receiving plates 10 arranged along the axial direction. The heat receiving plates 10 are rectangular structures and are radially distributed around the outer peripheral surface of the inner cylinder.

[0048] The remaining structures and functions may refer to those described in the first embodiment.

Claims

1. A solidified substrate sleeve rounding machine for vitrification of nuclear waste, characterized in that: It comprises a furnace body with a hot environment inside, wherein an outer cylinder and an inner cylinder which can rotate concentrically at a uniform speed are arranged in the furnace body, a feed port is arranged at the same end of the outer cylinder and the inner cylinder, and a discharge port is arranged at the other end, and the feed ports of the outer cylinder and the inner cylinder are arranged slightly higher than the discharge port; the hot environment temperature in the furnace body is distributed in a mountain shape or a trapezoidal shape along the axial direction of the outer cylinder and the inner cylinder.

2. The solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 1, characterized in that: The outer peripheral surface of the inner cylinder is provided with a plurality of rows of heat receiving fins arranged in the radial direction.

3. A solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 2, characterized in that: The heat receiving plate is a circular ring structure.

4. The solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 3, characterized in that: The spacings between the heat receiving plates of the circular ring structure are equal or unequal.

5. The solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 3, characterized in that: The outer diameters of the heat-receiving plates of the multiple rows of the circular ring structures are equal or unequal.

6. The solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 1, characterized in that: The outer peripheral surface of the inner cylinder is provided with a spiral heating surface.

7. A solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 6, characterized in that: The pitches of the spiral heating surfaces are equal or unequal.

8. The solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 1, characterized in that: The outer peripheral surface of the inner cylinder is provided with a plurality of rows of heat receiving fins arranged along the axial direction.

9. A solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 8, characterized in that: The heat receiving plates are rectangular in structure and are radially distributed around the outer peripheral surface of the inner cylinder.

10. The solidified substrate sleeve round polishing machine for nuclear waste vitrification according to claim 1, characterized in that: The outer cylinder and the inner cylinder are both connected to corresponding driving parts for driving them to rotate.

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