阅读说明：本技术 一种煤环流热解装置及其工作方法 (Coal circulation pyrolysis device and working method thereof ) 是由 彭丽 邹重恩 董方 石战胜 马治安 张伟阔 敬旭业 于 2020-04-03 设计创作，主要内容包括：本发明公开了一种煤环流热解装置及其工作方法,装置由上至下依次设有热解产物输送段、热载体与热解产物分离段、环流热解反应段、热载体输出段；热解产物输送段和热载体输出段分别用于将热解油气产品和换热后的热载体快速引出煤环流热解装置；热载体与热解产物分离段包括上锥段、中间段、下锥段,用于将热解油气产品与热载体高效、快速分离；环流热解反应段设置有导流筒、煤给料口、热载体给料口、煤与热载体预混合段、布风板、出风口、风室和进气口,用于煤和热载体的混合、传热,以及煤的热解。本发明有效保证了煤和热载体的混合、换热行为,以及煤在热解器内停留时间,实现煤的充分热解,并减弱热解油气二次裂解反应,提高热解油气收率。(The invention discloses a coal circulation pyrolysis device and a working method thereof, wherein the device is sequentially provided with a pyrolysis product conveying section, a heat carrier and pyrolysis product separating section, a circulation pyrolysis reaction section and a heat carrier output section from top to bottom; the pyrolysis product conveying section and the heat carrier output section are respectively used for rapidly leading the pyrolysis oil gas product and the heat-exchanged heat carrier out of the coal circulation pyrolysis device; the heat carrier and pyrolysis product separation section comprises an upper conical section, a middle section and a lower conical section and is used for efficiently and quickly separating pyrolysis oil gas products from the heat carrier; the circulation pyrolysis reaction section is provided with a guide cylinder, a coal feeding port, a heat carrier feeding port, a coal and heat carrier premixing section, an air distribution plate, an air outlet, an air chamber and an air inlet, and is used for mixing and heat transfer of coal and heat carriers and pyrolysis of the coal. The invention effectively ensures the mixing and heat exchange behaviors of coal and heat carrier and the retention time of coal in the pyrolyzer, realizes the full pyrolysis of coal, weakens the secondary pyrolysis reaction of pyrolysis oil gas and improves the yield of pyrolysis oil gas.)

1. A coal circulation pyrolysis device is characterized by comprising a pyrolysis product conveying section (1), a heat carrier and pyrolysis product separation section (2), a circulation pyrolysis reaction section (3) and a heat carrier output section (4), wherein the pyrolysis product conveying section (1), the heat carrier and pyrolysis product separation section (2), the circulation pyrolysis reaction section (3) and the heat carrier output section (4) are sequentially arranged from top to bottom; the heat carrier and pyrolysis product separation section (2) comprises an upper conical section (5), a middle section (6) and a lower conical section (7), the upper conical section (5) is communicated with the bottom end of the pyrolysis product conveying section (1), the upper conical section (5), the middle section (6) and the lower conical section (7) are sequentially communicated from top to bottom, and the upper conical section (5), the middle section (6) and the lower conical section (7) are coaxially arranged with the pyrolysis product conveying section (1); the circulation pyrolysis reaction section (3) is communicated with the bottom end of the lower conical section (7) and is coaxially arranged with the heat carrier and pyrolysis product separation section (2), the circulation pyrolysis reaction section (3) is provided with a guide cylinder (8), a coal feeding port (11), a heat carrier feeding port (12), a coal and heat carrier premixing section (13), an air distribution plate (14), an air outlet (15), an air chamber (16) and an air inlet (17), and the air distribution plate (14) is positioned between the coal and heat carrier premixing section (13) and the air chamber (16) and is used for ensuring uniform fluidization of the coal and the heat carrier in the circulation pyrolysis reaction section (3); the air outlets (15) are vertically and uniformly distributed on the air distribution plate (14); the air chamber (16) is of an inverted cone structure and is used for providing an air pressure stabilizing area before lifting gas enters the air distribution plate (14); the air inlet (17) is positioned outside the air chamber (16); the guide cylinder (8) and the circulation pyrolysis reaction section (3) are coaxially arranged, a guide area (9) is arranged inside the guide cylinder (8), an annular space between the guide cylinder (8) and the circulation pyrolysis reaction section (3) is an annular space area (10), and the coal feeding port (11) and the heat carrier feeding port (12) are respectively positioned on two sides of the circulation pyrolysis reaction section (3); the heat carrier output section (4) vertically runs through the air distribution plate (14) and the air chamber (16), the top end of the heat carrier output section (4) is flush with the top end of the air distribution plate (14), and the bottom end of the heat carrier output section (4) is located at the lower end of the air chamber (16).

2. A coal circulation pyrolysis apparatus according to claim 1, wherein the height of the pyrolysis product conveying section (1) is 1.5 to 3 times the height of the circulation pyrolysis reaction section (3), and the diameter of the pyrolysis product conveying section (1) is 10 to 30% of the diameter of the circulation pyrolysis reaction section (3).

3. A coal circulation pyrolysis device according to claim 1, characterized in that the height of the lower cone section (7) is 5-20% of the height of the circulation pyrolysis reaction section (3), the axial included angle between the lower cone section (7) and the circulation pyrolysis reaction section (3) is 30-60 °, the height of the middle section (6) is 50-100% of the height of the lower cone section (7), the height of the upper cone section (5) is 50-100% of the height of the middle section (6), and the axial included angle between the upper cone section (5) and the circulation pyrolysis reaction section (3) is 30-60 °.

4. The coal circulation pyrolysis device according to claim 1, wherein the diameter of the guide shell (8) is 0.4-0.7 times of the diameter of the circulation pyrolysis reaction section (3), the height of the guide shell (8) is 50-80% of the height of the circulation pyrolysis reaction section (3), and the vertical distance between the bottom of the guide shell (8) and the bottom of the circulation pyrolysis reaction section (3) is 10-25% of the height of the circulation pyrolysis reaction section (3); the height of the coal feeding port (11) is 50-80% of that of the circulation pyrolysis reaction section (3), and the axial included angle between the coal feeding port (11) and the circulation pyrolysis reaction section (3) is 30-90 degrees; the height of heat carrier feed inlet (12) is 50~80% of the height of circulation pyrolytic reaction section (3), heat carrier feed inlet (12) with the axis contained angle scope of circulation pyrolytic reaction section (3) is 30~ 90.

5. A coal circulation pyrolysis device according to claim 1, characterized in that the number of the air outlets (15) is 60-100, and the number of the heat carrier output sections (4) is 1-7.

6. A method of operating a coal loop pyrolysis apparatus as claimed in any one of claims 1 to 5, characterized by the following steps:

the lifting gas enters the air chamber (16) from the air inlet (17), the air chamber (16) provides an air pressure stabilizing area before the lifting gas enters the air distribution plate (14), the air chamber is a place for dynamic and static pressure conversion, the uniformity of air distribution is facilitated, and by regulating and controlling the lifting gas quantity of the air inlet (17), thereby controlling the lifting gas quantity of the air outlet (15) on the air distribution plate (14), leading the apparent speed of the lifting gas of the flow guide area (9) to be larger than the apparent speed of the lifting gas of the annular space area (10), ensuring that the pressure of the flow guide area (9) at the bottom of the guide cylinder (8) is larger than the pressure of the annular space area (10), realizing that coal and heat carrier respectively from the coal feed inlet (11) and the heat carrier feed inlet (12) flow downwards in the annular space of the annular space area (10) and then enter the bottom edge of the guide cylinder (8), the coal and the heat carrier flow along the edge to the center of the flow guide area (9), and the coal and the heat carrier flow in the circulation pyrolysis reaction section (3) for 5-20 times and then flow out;

the pyrolyzed pyrolysis products and the heat carrier flow into a heat carrier and pyrolysis product separation section (2) along a circulation pyrolysis reaction section (3), and the heat carrier and pyrolysis product separation section (2) is divided into an upper conical section (5), a middle section (6) and a lower conical section (7) by adopting a mode of expanding at first and then reducing the diameter;

the lower conical section (7) effectively reduces the apparent gas velocity of the lifting gas, strengthens the grading behavior of the pyrolysis oil gas product and the heat carrier, enables the pyrolysis oil gas product and the heat carrier to be efficiently and quickly separated, effectively ensures that the pyrolysis oil gas quickly flows into the middle section (6), the upper conical section (5) and the pyrolysis product conveying section (1) from the lower conical section (7) in sequence, and simultaneously ensures that the heat-exchanged heat carrier quickly flows into the heat carrier output section (4) from the heat carrier and pyrolysis product separating section (2) downwards through the circulation pyrolysis reaction section (3);

and finally, the apparent gas velocity of the lifting gas is rapidly increased by reducing the diameter of the pyrolysis product conveying section (1), the conveying of coke particles floating on the upper conical section (5) after the classification in the heat carrier and pyrolysis product separation section (2) is strengthened, the retention time of pyrolysis oil gas in the pyrolysis product conveying section (1) is shortened, and the secondary cracking reaction of the pyrolysis oil gas in the pyrolysis product conveying section is weakened.

Technical Field

The invention relates to the field of coal chemical industry and energy, in particular to a coal circulation pyrolysis device.

Background

China is the biggest coal producing country and consuming country in the world, and the energy characteristics of rich coal, poor oil and less gas determine that the coal is not shaken as the leading consuming energy of China for a long period of time. The low-rank coal resources in China are rich, and account for about 42.46 percent of the coal resources proven to be reserved in China. The low-rank coal has more side chains in the chemical structure, higher hydrogen and oxygen contents, has the characteristics of large moisture, low calorific value, good chemical reactivity, flammability, frangibility and the like, and is not suitable for long-distance transportation and storage. The existing low-rank coal processing and utilizing technology comprises direct combustion power generation, direct liquefaction, gasification and quality improvement processing. Compared with the low-rank coal combustion, gasification and liquefaction processes, the low-rank coal pyrolysis process can convert the low-rank coal into solid, liquid and gaseous products, and is an important method for realizing clean utilization of the low-rank coal.

Chinese patent publication No. CN108728137B discloses a low-rank coal fast pyrolysis device, which sets up multilayer agitator in the pyrolysis chamber, heats and stirs the coal through the agitator. The disadvantages are that: (1) the coal dust particles are fed from the top of the pyrolysis device and move from top to bottom along the pyrolysis chamber, and the violent downward movement of the coal dust particles may cause erosion and abrasion phenomena of a key part stirrer supplying heat in the pyrolysis chamber. Wear can consume stirrer surface material, reduce stirrer life, cause unsafe factors and cause greater economic loss; (2) the coal powder falling in the pyrolysis chamber contacts with the stirrer, exchanges heat, and is pyrolyzed under the stirring and heating of the stirrer to generate semicoke and oil gas. The semicoke and oil gas are easy to adhere and accumulate on the surface of the stirrer, especially the coal contains complex salt and alkali components which are easy to adhere in a high-temperature melting state, so that the contamination of the stirrer is caused, and the heat transfer effect of the stirrer is influenced; (3) the pulverized coal particles of the device are fed from the upper part of the pyrolysis chamber, pyrolysis products are obtained through pyrolysis of the pyrolysis chamber, and the products flow into the lower part of the pyrolysis chamber, so that the pyrolysis chamber of the device is a typical downer, and the pulverized coal particles stay in the pyrolysis chamber for a short time, which is not beneficial to full pyrolysis of large-particle pulverized coal; (4) a plurality of stirrers are arranged in the pyrolysis chamber, so that the whole device is complex in structure, complex in operation and high in energy consumption.

Chinese patent publication No. CN105238426B discloses a detachable plate type indirect heating coal pyrolysis device, which adopts heat exchange plates to heat coal for pyrolysis, and has the following disadvantages: (1) substances such as tar and dust can be generated in the coal pyrolysis process to contaminate the heat exchange plate, so that the heat exchange efficiency of the heat exchange plate is reduced, the frequency of periodic cleaning is increased, meanwhile, the heat exchange plate works at a high temperature of a gas phase and a solid phase for a long time, and the detection and replacement frequency of local parts of the heat exchange plate is increased; (2) a plurality of heat exchange plates are filled in the pyrolysis chamber, so that the coal powder pyrolysis space is occupied, and the processing capacity of the device is influenced; (3) the device is a typical downer, and the retention time of pulverized coal particles in the downer is short, so that the device is not beneficial to the full pyrolysis of large-particle pulverized coal.

Chinese patent publication No. CN209619268U discloses a pyrolysis furnace for filling internal components, which is a device for heating coal material to perform pyrolysis by arranging a plurality of mutually parallel pyrolysis walls in the furnace body, and has the following disadvantages: (1) the pyrolysis walls are arranged at the bottom of the furnace body, so that heat absorption of coal at the upper part of the hearth is not facilitated, and the heat transfer efficiency of the whole system is low; (2) the coal loosening device is arranged on the upper portion of the furnace body, so that extrusion of the upper coal seam to the lower coal seam is only avoided, gaps in the coal seams are still small, heat absorption of coal materials is not facilitated, and sufficient pyrolysis of the coal materials is difficult to guarantee.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a novel coal circulation pyrolysis device with a reasonable structural design, so as to solve the problems that two solid particles with different temperatures, namely large-particle pulverized coal and a heat carrier are mixed and heat exchange is not uniform, the retention time of coal in a reactor is short, pyrolysis is insufficient, the yield of pyrolysis products is low, and secondary pyrolysis of pyrolysis oil gas is serious.

The technical scheme adopted by the invention for solving the problems is as follows: a coal circulation pyrolysis device is characterized by comprising a pyrolysis product conveying section, a heat carrier and pyrolysis product separation section, a circulation pyrolysis reaction section and a heat carrier output section, wherein the pyrolysis product conveying section, the heat carrier and pyrolysis product separation section, the circulation pyrolysis reaction section and the heat carrier output section are sequentially arranged from top to bottom;

in the coal circulation pyrolysis device, the pyrolysis product conveying section is used for rapidly leading pyrolysis oil gas products out of the coal circulation pyrolysis device and weakening secondary pyrolysis reaction of the pyrolysis oil gas; the height of the pyrolysis product conveying section is 1.5-3 times of the height of the circulation pyrolysis reaction section, and the diameter of the pyrolysis product conveying section is 10-30% of the diameter of the circulation pyrolysis reaction section.

In the coal circulation pyrolysis device, the heat carrier and pyrolysis product separation section is used for reducing the apparent gas velocity, efficiently and quickly separating pyrolysis oil gas products from the heat carrier, and enabling the pyrolysis oil gas to quickly flow into the pyrolysis product conveying section; the heat carrier and pyrolysis product separation section comprises an upper conical section, a middle section and a lower conical section, the upper conical section is communicated with the bottom end of the pyrolysis product conveying section, the upper conical section, the middle section and the lower conical section are sequentially communicated from top to bottom, and the upper conical section, the middle section and the lower conical section are coaxially arranged with the pyrolysis product conveying section;

in the coal circulation pyrolysis device, the height of the lower conical section is 5-20% of the height of the circulation pyrolysis reaction section, the axial included angle between the lower conical section and the circulation pyrolysis reaction section is 30-60 °, the height of the middle section is 50-100% of the height of the lower conical section, the height of the upper conical section is 50-100% of the height of the middle section, and the axial included angle between the upper conical section and the circulation pyrolysis reaction section is 30-60%.

In the coal circulation pyrolysis device, the circulation pyrolysis reaction section is communicated with the bottom end of the lower conical section and is coaxially arranged with the heat carrier and pyrolysis product separation section, and the circulation pyrolysis reaction section is provided with a guide cylinder, a coal feeding port, a heat carrier feeding port, a coal and heat carrier premixing section, an air distribution plate, an air outlet, an air chamber and an air inlet; the air distribution plate is positioned between the coal and heat carrier premixing section and the air chamber and is used for ensuring the uniform fluidization of the coal and the heat carrier in the circulation pyrolysis reaction section; the air outlets are vertically and uniformly distributed on the air distribution plate, and the number of the air outlets is 60-100; the air chamber is of an inverted cone structure, is used for providing an air pressure stabilizing area before lifting gas enters the air distribution plate, is a place for converting dynamic pressure and static pressure, and is beneficial to the uniformity of air distribution; the air inlet is positioned at the outer side of the air chamber;

the circulation pyrolysis reaction section divides the pyrolysis reaction zone into the flow guide zone and the annular space zone by adding the flow guide cylinder, so that the mixing and heat exchange behaviors of large-particle pulverized coal and a heat carrier are enhanced, the retention time of coal in the circulation pyrolysis reaction section is prolonged, the full pyrolysis of the coal is realized, and the yield of pyrolysis oil gas is improved;

in the coal circulation pyrolysis device, the guide shell and the circulation pyrolysis reaction section are coaxially arranged, a guide area is arranged inside the guide shell, an annular space between the guide shell and the circulation pyrolysis reaction section is an annular space, and the coal feeding port and the heat carrier feeding port are respectively located on two sides of the circulation pyrolysis reaction section;

in the coal circulation pyrolysis device, the diameter of the guide cylinder is 0.4-0.7 times of the diameter of the circulation pyrolysis reaction section, the height of the guide cylinder is 50-80% of the height of the circulation pyrolysis reaction section, and the vertical distance between the bottom of the guide cylinder and the bottom of the circulation pyrolysis reaction section is 10-25% of the height of the circulation pyrolysis reaction section;

in the coal circulation pyrolysis device, the height of the coal feeding port is 50-80% of the height of the circulation pyrolysis reaction section, and the axial included angle between the coal feeding port and the circulation pyrolysis reaction section is 30-90 degrees; the height of the heat carrier feeding port is 50-80% of the height of the circulation pyrolysis reaction section, and the range of an included angle between the heat carrier feeding port and the axis of the circulation pyrolysis reaction section is 30-90 degrees.

In the coal circulation pyrolysis device, the heat carrier output section is used for efficiently and quickly moving the heat carrier subjected to heat exchange out of the coal circulation pyrolysis device; the heat carrier output section perpendicularly runs through in air distribution plate and plenum, just the top of heat carrier output section with the top of air distribution plate flushes, the bottom of heat carrier output section is located the lower extreme of plenum, the quantity of heat carrier output section is 1~ 7.

The working method of the coal circulation pyrolysis device is characterized by comprising the following steps:

lifting gas enters an air chamber from an air inlet, the air chamber provides an air pressure stabilizing area before the lifting gas enters an air distribution plate, the air chamber is a place for dynamic and static pressure conversion, air distribution uniformity is facilitated, the lifting gas quantity of the air inlet is regulated, the lifting gas quantity of an air outlet on the air distribution plate is controlled, the lifting gas apparent velocity of a flow guide area is larger than the lifting gas apparent velocity of an annular space area, the pressure of the flow guide area at the bottom of a flow guide cylinder is ensured to be larger than the pressure of the annular space area, coal and a heat carrier from a coal feeding port and a heat carrier feeding port respectively flow downwards in the annular space of the annular space area, then the coal and the heat carrier enter the bottom edge of the flow guide cylinder and flow towards the center of the flow guide area along the edge, and the coal and the heat carrier flow out after;

the pyrolysis product and the heat carrier after pyrolysis flow into the heat carrier and pyrolysis product separation section along the circulation pyrolysis reaction section, and the heat carrier and pyrolysis product separation section is divided into an upper conical section, a middle section and a lower conical section by adopting a mode of expanding firstly and reducing secondly.

The lower conical section effectively reduces the apparent gas velocity of the lifting gas, strengthens the grading behavior of the pyrolysis oil gas product and the heat carrier, enables the pyrolysis oil gas product and the heat carrier to be efficiently and quickly separated, effectively ensures that the pyrolysis oil gas rapidly flows into the middle section, the upper conical section and the pyrolysis product conveying section from the lower conical section in sequence, and simultaneously ensures that the heat carrier after heat exchange rapidly flows into the heat carrier output section from the heat carrier and the pyrolysis product separating section downwards through the circulation pyrolysis reaction section.

And finally, the apparent gas velocity of the lifting gas is rapidly improved by reducing the diameter of the pyrolysis product conveying section, the conveying of coke particles floating on the upper conical section after grading completion in the heat carrier and pyrolysis product separation section is enhanced, the retention time of pyrolysis oil gas in the pyrolysis product conveying section is shortened, and the secondary cracking reaction of the pyrolysis oil gas in the pyrolysis product conveying section is weakened.

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

according to the circulation pyrolysis reaction section, the guide flow area and the annular space area are formed by arranging the guide flow cylinder at the lower part of the device, and the coal particles and the heat carrier directionally flow in the circulation pyrolysis reaction section and form multiple circulations by regulating and controlling the lifting gas amounts on the guide flow area air distribution plate and the annular space area air distribution plate below the guide flow area and the annular space area, so that uniform mixing and heat exchange of the coal particles and the heat carrier are effectively ensured, the retention time of coal is prolonged, and the yield of pyrolysis oil gas is improved.

In the heat carrier and pyrolysis product separation section, the apparent gas velocity of the lifting gas is reduced by expanding and reducing the diameter of the middle part of the device, the grading behavior of the pyrolysis oil gas product and the heat carrier is strengthened, the pyrolysis oil gas product and the heat carrier are separated efficiently and quickly, and the pyrolysis oil gas is effectively ensured to flow into the pyrolysis product conveying section quickly.

The pyrolysis product conveying section rapidly improves the apparent gas velocity of the lifting gas in a diameter reducing mode at the upper part of the device, strengthens the conveying of coke particles floating at the upper part of a bed layer after the middle part is graded, can reduce the retention time of pyrolysis oil gas, and weakens the secondary pyrolysis reaction of the pyrolysis oil gas.

The invention has simple structural design, convenient operation, easy realization of scale production, strong adaptability to coal types and adaptability to non-caking coal, weak caking coal and strong caking coal.

Drawings

FIG. 1 is a schematic structural diagram of a coal circulation pyrolysis device in an embodiment of the invention.

Fig. 2 is a schematic structural view of the air distribution plate in fig. 1.

In the figure: the device comprises a pyrolysis product conveying section 1, a heat carrier and pyrolysis product separation section 2, a circulation pyrolysis reaction section 3, a heat carrier output section 4, an upper conical section 5, a middle section 6, a lower conical section 7, a guide cylinder 8, a guide area 9, an annular space area 10, a coal feeding port 11, a heat carrier feeding port 12, a coal and heat carrier premixing section 13, an air distribution plate 14, an air outlet 15, an air chamber 16 and an air inlet 17.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.