section Home
Production, Amateur
Radio amateur
Model aircraft, rocket-
Useful, entertaining 		Stealth master
Electronics
Physics
Technologies
invention 		space Mystery
Earth Mysteries
Secrets of the Ocean
Stealth
section Map
Start
Forum
Use of material is permitted for reference (for websites - hyperlinks)
INVENTION
Russian Federation Patent RU2065219

Combustible gas generator PROCESSING OF RADIOACTIVE WASTE

Combustible gas generator PROCESSING OF RADIOACTIVE WASTE

Name of the inventor: Kolchanov Grigory [BY]; Naganov Alexander Valerianovich [BY]; Savushkin Igor [BY]
The name of the patentee: Institute of the Academy of Sciences of Belarus Energy (BY)
Address for correspondence:
Starting date of the patent: 1992.03.26

Use: means of thermal processing of combustible radioactive waste. Summary of the invention: to reduce the amount of solid waste coming after processing for burial under the rotating milling bars placed on the bottom of the gasifier with a gap set fixed grating, which layers are bombarded with balls of refractory wear resistant material, number of layers from 3 to 6; and which has radial profile strips whose height is not less than the diameter of the balls. The diameter of the balls is not more than the gap between the grid and the milling gas generator housing and at least 1/30 of this value.

DESCRIPTION OF THE INVENTION

The invention relates to a technique for the management of radioactive waste (RW), namely with combustible waste, which compaction is carried out due to their thermal processing.

Currently, the most common method of thermal processing of combustible waste is to burn (see. Eg, Sobolev IA Homchik LM "Decontamination of radioactive waste at centralized locations." M. Energoatomisdat. 1983, pp. 19, 35).

At the same time more than 90 radionuclides remain in the bottom ash, which is well-known ways. Cementation, vitrification, etc. are conditioned and sent for disposal.

However, known methods of combustion have substantial disadvantage that require cleaning flue gases from radionuclides (from the remaining 10 contained in the waste), and a large amount of gases produced during combustion, increases the size and cost of the gas cleaning system.

Gasification can be regarded as a method of compacting solid combustible waste, which in comparison with the combustion can significantly reduce the amount of gas purification. In this case not be cleaned flue gases with a substantial excess of air, and the product gas obtained with little air volumetric output of which is approximately 2 times smaller than the volume of flue gas from the same amount of starting material.

Various gasifiers for processing combustible waste. For example, in the article Salamova AA "incineration and gasification of waste wood", the magazine "Industrial Energy" .N 2, 1985, p. 52 54.

However, in the known gas generators can not accommodate processing of radioactive waste, nedozhega high percentage that increases the amount to be disposed of radioactive substances and increases the cost of air conditioning and disposal of bottom ash.

Known and gas generators with rotating milling (or other type of) bars, which provide continuous removal of ash and slag, and thereby improve performance on gas quality, performance, and burning residues such as gas generators described in the book Ginzburg DB "Gasification of solid fuels." M. Gosstroiizdat. 1958, p. 24, 30, Fig. 2, 4.

However, in these designs is nedozheg May 12 (see ibid., P. 97), which leads to a loss of energy, and an increase in the costs of disposal of radioactive waste.

From the prior art closest to the object of the invention is a gas generator shown in the explanatory note to the "Technical Proposal on the technology of gasification of organic (wood) radioactive waste residues and the choice of the gas generator design," ANC IFMO them. AV Lykov. Minsk. 1991, p. 61, Fig. 24, taken as a prototype.

Taken as a prototype gasifier for processing combustible radioactive waste contains a charging device, a mine, an injector ignition, rotary milling grille mounted with a clearance in the housing and by a shaft connected to the actuator, the air supply pipes and discharge of the product gas, ash removal device and the gas density of the device .

Taken as a prototype gasifier operates at a combined process with a dual air and fuel afterburning feed from the bottom, that allows for relatively small dimensions of recycling waste, the preparation of generating gas and a small amount of radioactive solid waste going to disposal.

However, as made by the study (see. Given as a prototype of the explanatory note of the ANC ITMO, p. 50 52) in gas generators with solid slag-ash removal irremovable carbon nedozheg is May 10 This is due to the unevenness of the blast at the shaft cross-section, limited process time generator set performance, and the height of the shaft (especially in the performance of the gasifier installation transportable conditions of work in the affected area of ​​the Chernobyl disaster) is limited, moreover, nedozheg cause uneven pieces of fuel, which is typical of waste.

Nedozheg increases the volume of solid waste received for disposal, which increases the costs and the excess secondary blast in the post-combustion zone, while reducing nedozheg, but the results thus generated gas to burn-in, which reduces the economic performance of the gas generator.

The technical solution achieved in the implementation of the invention is to reduce the mechanical nedozhega gasifier.

To achieve this result, in the gas generator for the processing of combustible radioactive waste, comprising a charging device, a mine, an injector ignition, rotary milling grille mounted with a clearance in the housing and by a shaft connected to the actuator, the air supply pipes and discharge of the product gas, ash handling equipment and devices providing gas density, the rotating grating mounted below the stationary grating on which balls are bombarded with a heat-resistant and wear-resistant material over which is mounted a drive shaft connected to the radial profile strips, the diameter of the balls is made equal in size from 1/30 to 1/1 of the gap between the grating and milling casing filling height is made such that the balls are placed therein from 3 to 6 layers, and the height above the profile strips fixed lattice formed of at least than the diameter of the balls.

A distinctive feature of the inventive design of the gas generator is filling the fixed lattice spheres of heat-resistant wear-resistant material and the installation of this grid rotary profile strips by which the filling of the balls is driven. At the same time filling simultaneously performs the function of the failed chopper through the gap and large pieces of inert layer function, in which the afterburning nedozhega.

Of these functions, the implementation flow limit value of this additional design features, namely, the diameter formed by the balls size of from 1/30 to 1/1 of the gap between the grid and the milling body, the height of the filling is made such that the balls are placed therein from 3 to six layers, and the height of the profile strips fixed level lattice formed of at least than the diameter of the balls.

Execution of spheres of diameter greater than the gap between the grid and the milling body, is impractical due to the fact that said gap typically operate largest radius equal to 1/3 the housing, and in view of the fact that part of the section occupied by milling grating drive shaft, when the ball diameter is greater than 1/3 of the radius in cross section between the shaft and the housing is placed no more than 2 rows of balls, which results in loose their placement, increased formation of correct dimensions, rapid breakthrough of unburned fuel through the filling pieces. The increase in the number of layers in the filling does not compensate for this disadvantage, and further increases the size of the furnace and leads to great losses of the drive power to move the balls.

By reducing the diameter of balls less than 1/30 of the gap, the magnitude of the diameter of the prevailing gas generators diameters of approximately 1 m is less than 1 cm, which leads to loss of the effect of the grinding balls and unburned pieces at the same time to the danger of occurrence of slag balls of the top cover -this reduce the size of their progress. In this case, again, the increase in the number of layers of filling does not result, and only exacerbates the negative effect korkoobrazovaniya. In connection with the foregoing the optimum size of the diameter of balls with a diameter of gasifier combustion portion 1m size will be 50 to 60 mm, which is within the specified range of 1/30 1/1 5160 mm.

The number of layers of balls in the filling height of 3 to 6 and the height of the profile strips above the fixed grille are determined from the optimum cost drive energy for movement of the balls (when filling over 6 layers move this mass becomes disadvantageous: the cost high, and the topsheet offset has little effect for capture and process the grinding of large pieces of fuel, fell into a gap between the grid and the milling body) and possible leakage of unburned pieces through the furnace filling (filling at least 3 layers of unburned pieces of a layer of balls can slip directly under the bar at the rolling balls through it).

From the same height calculation profile strips than the diameter of balls will cause an undesirable increase in losses in the actuator and balls raking effect with the possibility of leakage of unburned residues strap directly to the output. At the height of strips less than the diameter of the balls perturbation effect is insufficient to capture large unburned pieces and fell into a gap t. E. Not used the possibility of unburned pieces of grinding balls of filling.

Thus, due to distinctive features, in this gas generator firebox, unlike the prototype, allows further grind nedozheg and retain particles of unburned fuel in the filling prior to complete digestion that precludes entering the bottom ash additional amount of material, reducing thereby the amount of solid radioactive possible to minimize waste, reducing disposal costs in comparison with other known units for processing combustible radioactive waste.

FIG. 1 is a schematic sectional view of the inventive gas generator; FIG. 2 and FIG. 3 is an enlarged bed of refractory balls. The gap between the grid and the milling body designated Height profile of the fixed grating strips level h, and the diameter of the filling balls d. Thus in FIG. 2 pieces of the fuel are depicted as polygons, spheres as circles, as profiled slat is provided in the form of plates; FIG. 3 shows a strip profile in the form of a wedge. The number of layers of balls to FIG. 2 and FIG. 3 is three.

The described gasifier comprises a charging device 1, the shaft 2, the nozzle firing three rotating milling grating 4 mounted in a housing 5 with a clearance D, the shaft 6, by which the milling grating coupled with a drive and via which supplied additional air to the afterburning air nozzles 7 and exhaust gas generator 8. The composition of the gas generator includes ash and devices and to provide a gas density in the form of collections of ash 9 with vanes 10, gate 11 on the nozzle supply valve 12 and the waste to ensure that the density of the gas feeding waste, water seal 13, providing the density of the rotating shaft 6 and the other devices on the pipelines and connector designs.

Following rotary milling lattice 4 is installed fixed grating 14 on which balls 15 are bombarded with the wear of a refractory material such as cast iron or special sintered materials. Above the fixed grid 14 installed and connected to the shaft 6, the radial profile strips 16 (FIG. 1 shows the filling with the front wall of the housing, strips are shown in phantom and in end view).

D Diameter of balls 15 is thus equal in magnitude from the magnitude of 1/30 to 1 D of the milling gap between bars 1 and the housing 5.



Height strap 16 h above the fixed grille 14 is not less than the diameter of balls 15 d

h d

The height of the filling balls formed so that the balls fit therein from 3 to 6 layers (FIGS. 1, 2 and 3 shows a filling layer 3 balls).

DESCRIBED gas generator works as follows

In the charging device 1, opening the gate 11, is charged with combustible radioactive waste, such as wood chips from the processing of tree trunks affected by radioactive releases during the Chernobyl disaster. The supply of waste into the pit 2 is carried out at a closed gate 11, opening the valve 12, and thus prevent a possible exit gases containing radioactive aerosols through the loading hatch.

Ignition of the gas generator are in a known manner, using, at the same time can be used "clean" fuel injector ignition 3 (M. Gosstroiizdat. 1958, p. 87 88 See. For example, referred to the monograph Ganzburg DB "Gasification of solid fuels."). Upon reaching the desired height of the burning fuel layer is filled with water seal 13, allowed to air blast nozzles 7, include the drive shaft 6 begins to rotate the milling grating 4 and a gas generator enters the working mode with a tap of the product gas through the pipe 8 to gas cleaning.

In this case the air preheated in the jacket casing 5 is fed into the shaft 2 from the top, the combustion zone is located in the body 5 and by the heat generated in the shaft 2 occurs predrying and dry distillation fuels thus released from the fuel tarry substance completely decomposed in the high temperature zone, which facilitates purification of the gas generator.

The product gas formed by the interaction between carbon fuels and fed into the gasifier blown into the hot bed of fuel is retained in the body 5, and is discharged to the gas cleaning from the upper part through the pipe 8. With the help of a rotating milling grating 4 is carried out loosening caked coke and coal, mixing and fuel distribution, the destruction of lumps of slag and ash disposal. A portion of additional air supplied through the shaft 6 enters the central zone of the housing 5 to ensure the stability and distribution of blast gasification mode.

Unburned coke and coal ash with slag and char large pieces of fuel fall through grate 4 by milling, the maximum size of the pieces being determined by the gap between the lattice 4 and the body 5.

All failure falls on the layers of filling 15 balls, which is purged through the rest of the supply through the shaft 6 additional blast. Filling of 15 balls are constantly moving profiled strips 16, which are mounted on the shaft 6 of the fixed grating 14.

Ash and other small particles of solids are poured over the intervals between the balls, and the carbon dookislyaetsya and the fixed grating 14 has received ash residues without nedozhega. Ash freely pass through the fixed grating 14, t. To. Are divided state and enter the collections of ash 9, which are periodically emptied into shipping containers through the dampers 10.

Capture larger pieces of unburned fuel into the gap between the balls 15 occurs when they pass under the profile section 16 and the step formation in the ball filling, as shown in FIG. 2 and FIG. 3. Since the profile height h strap is made not less than the diameter d of the balls, by passing strap 16 under the next ball near the height of backfill changes abruptly by an amount h, t. E. The interaction is broken layers of balls vertically, the balls 15 are moved apart, as it were, and capture pieces fuel commensurate with the diameter of the balls as depicted in FIGS. 2 and FIG. 3. In this case there may be instances where larger pieces fall between the balls and following the gaps between the upper layers, as shown in FIG. 2. In any case, being between warmed balls, interacting with them as they move and interact with the blower in the air filling, pieces nedozhega actively oxidized. Formed on the surface of the pieces of ash actively erased balls and goes through the grid 14 in the collections of ash, pieces of the dimensions are reduced to their complete combustion.

Thus nedozhega pieces exceeding the diameter size balls remain on the surface prior to filling until obgorite not begin to disintegrate and fall into the space between the balls as described above.

Reducing the diameter of the balls of filling reduces the loss of their respective profile stir bar, but it is possible to bridging of ash over the pebble bed with the violation of the operating mode of the gas generator. Experiments have shown that this is possible with bridging profile section height h, of 5 mm or less, which is about 1/30 the gap D between the lattice 4 and the milling body 5 gasifiers existing designs.

Increasing the diameter of the balls d more than the value of the gap D, which determines the size of the pieces of unburned fuel, it is impractical, as well as an increase in thickness of more than 6 layers of filling balls due to increased expenses for filling stirring. As shown by the checks carried out and the calculations for the gas generator, working on wood waste or wood chips with dimensions and characteristics similar to the gasifier, given as a prototype, is the optimal filling of balls with a diameter of 50 60 mm and 3, 4 layers on a fixed grid. This provides virtually complete burnout nedozhega that reduces the amount of ash, respectively.

Thus, in comparison with the prototype, the claimed gasifier operates at a total processing incoming combustible materials by reducing the mechanical nedozhega 5 10 to a value less than 1 February (according to calculations based on the model experiments) that when a large amount of radioactive waste generated a result of the Chernobyl disaster and can be recycled, resulting in a significant reduction in their burial expenses.

CLAIM

The gas generator for processing combustible radioactive waste, comprising a shaft at the top portion of the housing of the gas generator, in its lower part with a gap set rotating milling grating having a drive shaft, which is simultaneously device supplying air to the central zone of the housing, wherein on the shaft arranged charging device, under which the mine is placed ignition nozzle, and a milling grating disposed device deashing, characterized in that between the rotating milling grating device and ashing installed fixed grating, which layers are bombarded with balls of refractory wear-resistant material, the diameter of which is less than the gap between the milling gasifier grate and the housing and at least 1/30 of this value with the number of layers 3 6 thus placed on the stationary grate connected to the drive shaft radial profile strips whose height is not less than the diameter of the balls.

print version
Publication date 20.02.2007gg