RU2698829C1 - Installation of pyrolytic processing of solid carbon-containing materials - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry, particularly, to thermal processing of solid carbon-containing materials. Proposed plant comprises power drive, zone of processed material compaction to gas-tight state and retort made in the form of pipe intended for thermal decomposition of material without air access. At that, at inlet to retort there is coaxially installed loading sealing device (LSD), which is made in form of variable-cross-section pipe and includes sealing zone, gas-tight zone and transit zone, at that, in gas-tight LSD zone in one row evenly along the perimeter there arranged is at least two adjustable stops equipped with gas seals with possibility of their overlapping up to 30 % of LSD passage section. Compaction zone and gas-tight zone of LSD are made with the same shape of passage cross-section with midsection D = 20–100 mm, and the length of the LSD sealing zone is (0.5–7.5)D and the length of the gas-tight LSD zone is (0.5–2.0)D. Transit zone of LSD and retort are made with identical flow section (1.02–1.08)D, length of transit zone of LSD is (0.5–2.0)D. At that, the length of the middle part increasing in the transit zone of the transition section increases from 0 to 0.15D, the stops are located at a distance of up to 0.2D from the border of the gas-tight zone and the transit zone of the LSD, between the power drive and the LSD there is a loading window with length of (1.0–5.0)D, and power drive piston is made with midsection (0.95–0.99)D and length of working stroke from zero point of guide, having length (0.1–3.0)D, to boundary of sealing zone and gas-tight zone of LSD, wherein retort without perforation and gas manifolds.

EFFECT: technical result consists in transition to structural-technological appearance of device, which allows to avoid strict maintenance of specified temperature in sealing, drying and pyrolysis zones, as well as to avoid use of perforation and gas collectors.

5 cl, 4 dwg, 1 ex

Description

The invention relates to equipment of the chemical industry, in particular to installations for the thermal processing of solid carbon-containing materials to produce gas, coke, tar and similar products.

Known installations of continuous periodic action for the pyrolysis of carbon-containing materials containing a feeder (which performs the formation of a sealed tube at the feeder-retort boundary and supplying the processed material to the retort) and a retort made in the form of a pipe for smoothly moving particles of the processed material through the compaction, drying and pyrolysis, with perforation in the heat supply zone and gas exhaust manifolds outside the retort for the collection and removal of volatile pyrolysis products. Due to the frictional forces arising between the loaded processed material (for example, biomass) and the inner surface of the retort, a gas-tight plug is formed from the source material, which provides a given level of tightness of the retort. Tightness is expressed in the impossibility of spontaneous penetration of the amount of thermal decomposition products significant for the pyrolysis process or violation of safety conditions outside the device into the environment. Due to the good adhesion of the compacted material to the walls of the retort in the drying zone, intense heat transfer is ensured. The retort is heated in any way possible: an electric heater, hot combustion products or otherwise. An example of a technical implementation of a device for use in thermal processing plants, including including a briquette press, is, for example, a device according to USSR patent No. 57761 “Loading device for high pressure gas generators”, priority dated 12/28/1936.

A disadvantage of the loading devices of such installations is the bulkiness and complexity of the design (including the sealing loops), which seems excessive for working with relatively low pressures.

A continuous pyrolysis apparatus is also known, which is described in RU Patent No. 2,408,654 “Continuous pyrolysis apparatus for the pyrolysis of carbon-containing materials”, priority dated 16.03.2009. The main elements of the installation are a storage hopper, a loading device equipped with a screw feeder-compactor, through which a continuous supply of crushed carbon-containing waste is realized inside the retort while achieving its tightness, retort, where the drying is carried out continuously, with the screw moving to the unloading unit, and pyrolysis of the processed material, as well as the removal of the resulting gaseous products through the gas removal system. A coupling of variable cross section is installed between the feeder and the retort to form a cork from the processed material to ensure a specified level of retort tightness.

The disadvantage of this installation is the cumbersome design, the relative technological complexity of manufacturing and assembly, due to the presence of a feed screw and a screw located in the retort, requiring the organization of remote bearing units and tight shaft seals in conditions of high temperature, acidic environment and the presence of abrasive particles. The area of direct contact of the processed material with the inner surface of the retort when using a screw is small. In addition, with equal diameters of the loading device, the screw provides less productivity than the piston. You cannot use a retort with a cross-section other than round.

The installation of thermal processing of carbon-containing materials described in patent RU 2613044, priority date 10.07.2015, was chosen as the closest analogue of the proposed technical solution. The main elements of the closest analogue are a power reciprocating mechanism with a drive, a piston, a guide, a cutout with a receiving tray, a retort, in which there are highlighted areas of sealing, drying and pyrolysis, perforation and gas collectors.

The disadvantage of the closest analogue is the need to maintain the required temperature of the retort wall in the areas of compaction, drying and pyrolysis. If the wall temperature is too low in the drying and pyrolysis zones, a significant increase in the friction force of the briquette from the compacted material on the retort walls occurs due to insufficient isolation of thermal decomposition products that act as a lubricant. This can lead to loss of system performance due to the inability to push new portions of material. This negative effect is eliminated only after heating the walls of the retort to the required temperature. In turn, when the working temperature of the retort wall is exceeded in the sealing zone, the drying and thermal decomposition process is intensified, which leads to a decrease in the level of sealing of the compacted material layer and an unaccounted for increased yield of thermal decomposition products. It should be noted in this regard that the process of adjusting the temperature of the retort wall depends on several parameters, including the consumption of the processed material, and this is problematic from the point of view of reliable automation and ensuring the safety of the installation. In addition, the mandatory presence of perforations and gas manifolds of the device, the closest analogue, leads to a decrease in the area of the outer heat exchange surface of the retort, creates technological difficulties (for example, when applying fins to the outer surface of the retort to increase the area of the heat exchange surface), complicates the manufacturing process of the installation, increases its overall dimensions and cost.

The technical result of the invention is the transition to the structural and technological appearance of the device, which avoids the strict maintenance of the set temperature in the areas of compaction, drying and pyrolysis, and also eliminates the use of perforation and gas reservoirs, which will reduce the weight and dimensions, the complexity of manufacturing, assembly and adjustment devices, expand the range of operating modes, provide the ability to change the compaction pressure of the processed material in a wide range, it square outer heat exchange surface of the retort and to enable application of high-tech fin (e.g., helical), further increasing the heat transfer area of the outer surface of the retort.

The specified technical result is achieved by the fact that in the installation for the pyrolysis of solid carbon-containing materials at the inlet to the retort, made in the form of a pipe, designed for thermal decomposition of the material without air access, coaxially installed sealed loading device (UZG), which is made in the form of a pipe of variable cross-section and includes a sealing zone, a gas tight zone and a transit zone, while at the same time in the gas tight zone of the ultrasonic testing machine at least two regulators equipped with gas seals are placed uniformly along the perimeter adjustable stops with the possibility of overlapping them up to 30% of the passage section of the ultrasonic wave, the sealing zone and the gas tight zone of the ultrasonic wave are made with the same shape of the passage cross section midsection D = 20 ... 100 mm, the length of the sealing zone of the ultrasonic wave is (0.5 ... 7.5) D, the length of the gas-tight zone of the ultrasonic testing is (0.5 ... 2.0) D, the transit zone of the ultrasonic testing and retort are made with the same cross-section (1.02 ... 1.08) D, the length of the transit zone of the ultrasonic testing is (0.5 ... 2.0 ) D, while the length of the transitional zone of the transition section of the increase in the midsection is from 0 to 0.15D, the stops are placed at a distance and up to 0.2 D from the boundary of the gas tight zone and the transit zone of the ultrasonic drive, between the power drive and the ultrasonic drive there is a loading window with a length of (1.0 ... 5.0) D, and the piston of the power drive is made with a midsection (0.95 ... 0.99) D and the stroke length from the zero point of the guide, having a length (0.1 ... 3.0) D, to the border of the sealing zone and the gas tight zone of the ultrasonic testing, while the retort is made without perforation and gas reservoirs. In addition, the line of movement of the emphasis during adjustment can be placed in the plane of the longitudinal axis of the ultrasonic scan at an angle of ± 60 ° to the normal to the longitudinal axis of the ultrasonic scan. Between the USG and the retort, a heat-insulating insert with a width of (0.1 ... 3.0) D with a midship equal to the midsection of the transit zone of the USG and the midsection of the retort can also be introduced. Retort can be performed with external finning. The sealing zone, the gas tight zone, the transit zone of the UZG and the retort can be made with the same flow area.

In FIG. 1 shows a schematic diagram of a device according to the proposed technical solution. In FIG. 2, 3 show the aspect ratio of the elements of the device. In FIG. 4 shows the cross section of the ultrasonic scan in the plane of the stops.

Designations accepted:

1 - power drive (for example, a hydraulic cylinder),

2 - piston

3 - guide,

4 - boot window

5 - tight boot device,

6 - emphasis

7 - heat-insulating insert (option),

8 - retort,

9 - ribbing (option),

10 - sealing zone,

11 - gas tight zone,

12 - transit zone.

The device according to the proposed technical solution has the following characteristic features (see Fig. 1). Installation, including power drive pos. 1 with piston pos. 2 and the guide pos. 3, is mounted on a rigid base (support, bed, foundation - not shown in Fig. 1) coaxially with the retort pos. 8. At the entrance to the retort is additionally installed ultrasound pos. 5 Sealing zone pos. 10, gas tight zone pos. 11 and the transit zone pos. 12 are functional sections of the ultrasound 5. Between the guide pos. 3 and ultrasound pos. 5 the loading window pos. 4, filled with recyclable material. Stops pos. 6 in an amount of not less than two are installed in the ultrasonic testing machine pos. 5 and are provided with gas seals (not shown in FIG. 1). Between UZG pos. 5 and retort pos. 8, to reduce the intensity of heat transfer, a heat-insulating insert pos. 7 (option). Retort Pos. 8 is made of a material with good thermal conductivity (for example, stainless steel) and may have fins pos. 9 (option) to further increase the area of the outer heat exchange surface. Open end retort pos. 8 is a yield for the thermal decomposition products of a carbonaceous material (volatile and carbonaceous residue). Heating retort pos. 8 can be carried out by any available method (for example, by means of electric heating or heating with hot flue gases) providing thermal energy through the wall with subsequent heat transfer to the processed material and its decomposition products.

The device according to the proposed technical solution operates as follows. Piston Pos. 2 power drive pos. 1 extends to the zero point of the guide pos. 3 (see Fig. 2), then the carbon-containing material is filled with the volume of the loading window pos. 4, after which the piston pos. 2 is inserted by the power drive pos. 1 in UZG pos. 5, pushing the material through the sealing zone pos. 10 (in which the processing material is densified due to the pressure force of the piston pos. 2 on the one hand and the resistance of the previously densified material in the gas tight zone of pos. 11 on the other hand). In the gas tight zone pos. 11, a briquette of compacted material is formed, which prevents the exit of volatile products of thermal decomposition of the material. Near the border of the gas tight zone pos. 11 and the transit zone pos. 12 briquette rests on the stops pos. 6, the position of which determines the magnitude of the sealing pressure: the greater the stops pos. 6 overlap the passage section of the ultrasonic scan pos. 5, the greater the magnitude of the seal pressure. The stops can be positioned at an angle of ± 60 ° relative to the normal to the axis of the ultrasonic scan (see Fig. 3). In a briquette of compacted material passing through the stops pos. 6, longitudinal grooves (gutters) are formed, the profile of which corresponds to the projection of the stops pos. 6 on the plane of the passage section of the ultrasound scan pos. 5. Experiments show that at a piston pressure of 5 MPa or more, sufficient material compaction occurs to create a gas-tight briquette. At the time when the pressure force from the piston side pos. 2 on the sealed recyclable material there is more friction between the sealed recyclable material and the wall (including the resistance of the stops pos. 6), the recyclable material begins to move from the gas-tight zone pos. 11 to the transit zone pos. 12. The movement of the compacted processed material occurs until the piston pos. 2 does not take its extreme position (at a distance of (0.5 ... 7.5) D from the loading window, item 4 deep into the sealing zone, item 10), then the piston item. 2 returns to its original position (zero point of the guide pos. 3), and the cycle repeats. Midships of the transit zone pos. 12, heat insulating insert pos. 7 and retorts pos. 8 more midsection of the gas-tight zone pos. 11, therefore, the friction force between the outgoing from the gas-tight zone pos. 11 compacted material and the walls of the transit zone pos. 12, heat insulating insert pos. 7 and retorts pos. 8 turns out to be relatively small in comparison with the resistance force arising during the passage of the gas-tight zone pos. 11. Heat-insulating insert pos. 7 (option) prevents heat transfer from the retort pos. 8 to UZG pos. 5, due to which the magnitude of the pressure of the seal is mainly determined by the position of the stops and practically does not depend on the temperature of the wall of the retort pos. 8. The transition section from the gas-tight zone pos. 11 to the transit zone pos. 12 can be either sharp (as shown in FIG. 3) or smooth.

Inside the retort pos. 8 heat is transferred from the retort wall pos. 8 to the processed material, leading first to the evaporation of moisture, and then thermal degradation (pyrolysis), then the products of thermal decomposition of the material in a different state of aggregation are released. Liquid products play the role of a lubricant that further reduces the friction force of the material briquette on the retort walls pos. 8. Gaseous products are mainly discharged through grooves (troughs) in the briquette, which are formed when the material passes through the stops pos. 6, which prevents the accumulation of gases under high pressure, stabilizes the installation and avoids the risk of rupture of the retort pos. 8. The presence of a gas-tight zone pos. 11 and gas seal stops pos. 6 guarantees a given level of tightness of the installation. Carbonaceous material residue and volatile, moving along the retort pos. 8 are removed through its open end to a place designated for the purpose of the installation for direct use or further processing. It should be noted that the proposed device also provides for the prevention of the accumulation of hard deposits (soot) on the walls of the retort pos. 8 due to its mechanical removal by moving compacted material and carbonaceous material residue.

Uniform circumferential arrangement of two or more stops pos. 6 allows you to avoid the appearance of asymmetric loads on the ultrasound scan pos. 5 from the side of the material being sealed, and also allows you to evenly distribute and output the flow of the resulting gaseous pyrolysis products. Due to the presence of a variable cross-section (enlarged to (1.02 ... 1.08) D mid-section of the transit zone, pos. 12 and retorts, pos. 8), the compaction pressure of the processed material is not regulated mainly by creating certain temperature conditions in the compaction, drying, and pyrolysis zones , and by adjusting the position of the stops pos. 6 in UZG pos. 5, which has a number of significant advantages (increasing the range of regulation of the pressure of the seal, reducing the inertia of the regulatory process, the absence of the need for supply and removal of heat). In the event that the midsection of all parts of the installation are equal (option), the presence of stops pos. 6 provides the ability to control seal pressure in addition to temperature control. The size of the midsection of the seal zone pos. 10 and tight zone pos. 11 UZG pos. 5 a restriction of 20 ... 100 mm is imposed, since the thermal processing of briquettes with a size of less than 20 mm is impractical from a practical point of view, and briquettes with a midsection of more than 100 mm will not sufficiently heat up the cross section in units of acceptable length. Midship piston pos. 2 power drive pos. 1 is (0.95 ... 0.99) D, which at the same time eliminates jamming of the piston pos. 2 and ensure sufficient alignment in the guide pos. 3 long (0.1 ... 3.0) D. The length of the loading window pos. 4 is (1 ... 5) D, which allows the bulk material to fill the cavity formed after each feed cycle, and the piston pos. 2 - carry out the supply of material to the ultrasonic testing machine pos. 5 with high efficiency. The length of the sealing zone pos. 10 (0.5 ... 7.5) D, gas tight zone pos. 11 (0.5 ... 2.0) D and transit zones pos. 12 (0.5 ... 2.0) D are selected empirically, taking into account the type of processed material. Stops pos. 6 can be installed both at the boundary of the gas tight zone pos. 11 and the transit zone pos. 12, and at some distance from it (up to 0.2D). Exclusion of perforation of the retort pos. 8 and gas collectors becomes possible due to the formation in the briquette of the compacted material grooves (grooves) formed in the briquette when it is pushed through the stops pos. 6 and performing the role of gas vents, which leads to a simplification of the manufacture and assembly of the installation, a decrease in weight and size indicators, an increase in the area of the outer heat-exchange surface of the retort, and also allows applying high-tech finning poses to the retort. 9 (for example, spiral) to further increase the area of the outer heat exchange surface. Setting the stops pos. 6 at an angle to the normal to the longitudinal axis of the ultrasonic scan (see Fig. 3) allows you to make changes to the process of forming grooves (grooves) in the briquette. When tilting the stops pos. 6 along the movement of the material, grooves (gutters) are formed due to crushing of the material and have clear boundaries, when the stops are tilted pos. 6 against the movement of the material grooves (gutters) are formed due to the gap of the material and do not have a clear boundary. Changing the angle of the stops pos. 6 also leads to a change in the magnitude of the adjusting force.

The application of the proposed technical solution is advisable for energetically and environmentally sound processing of carbon-containing materials both in small volumes (laboratory, pilot production), and in large volumes (for example, during logging, utilization of agricultural waste, etc.). At the same time, the relative simplicity of the structural layout of the installation, the possibility of scaling its dimensions, the formation of a “cross-sectional” profile of the ultrasound and retort, the variability of the power mechanisms and heat sources (generators) make it possible to predict the relevance of the proposed technical solution in modern conditions and in the foreseeable future .

Claims (5)

1. Installation of pyrolytic processing of solid carbon-containing materials, containing a power drive, a sealing zone of the processed material to a gas-tight state and a retort made in the form of a pipe designed for thermal decomposition of the material without air access, characterized in that a sealed loading device is coaxially installed at the inlet of the retort (UZG), which is made in the form of a pipe of variable cross section and includes a sealing zone, a gas tight zone and a transit zone, while in the gas tight zone of UZG one at least two adjustable stops equipped with gas seals are arranged evenly around the perimeter with the possibility of overlapping by them up to 30% of the UZG passage section, the sealing zone and the gas tight zone of the UZG are made with the same shape of the passage cross section by the midsection D = 20-100 mm, the length of the UZG seal zone is (0.5-7.5) D, the length of the gas-tight zone of the ultrasonic testing is (0.5-2.0) D, the transit zone of the ultrasonic testing and retort are made with the same bore (1.02-1.08) D, the length of the zone UZG transit is (0.5-2.0) D, while the length of the transit zone p the transition section of the increase in the midsection is from 0 to 0.15D, the stops are placed at a distance of up to 0.2D from the boundary of the gas tight zone and the transit zone of the UZG, between the power drive and the UZG a loading window is made of length (1.0-5.0) D, and the power drive piston is made with a midsection (0.95-0.99) D and a stroke length from the zero point of the guide, having a length (0.1-3.0) D, to the boundary of the sealing zone and the gas tight zone of the ultrasonic testing, while the retort made without perforation and gas reservoirs. 2. The pyrolytic processing unit for processing solid carbon-containing materials according to claim 1, characterized in that the line of movement of the stop during adjustment is placed in the plane of the longitudinal axis of the ultrasonic scan at an angle of ± 60 ° to the normal to the longitudinal axis of the ultrasonic scan. 3. The pyrolytic processing unit for processing solid carbon-containing materials according to claim 1, characterized in that a heat-insulating insert with a width of (0.1-1.0) D with a midship equal to the middle of the transit zone of the USG and the middle of the retort is inserted between the ultrasonic wave and the retort. 4. Installation pyrolytic processing of solid carbonaceous materials according to claim 1, characterized in that the retort is made with an external finning. 5. The pyrolytic processing unit for processing solid carbon-containing materials according to claim 1, characterized in that the sealing zone, gas tight zone, transit zone of ultrasonic scanning and retort are made with the same flow area.

Images