Fixed fluidized disturbed bed drying system

Abstract

The utility model provides a fixed fluidized perturbation bed drying system, the device comprises a fixed fluidized bed, a roller screen and a heat source device, the fixed fluidized bed comprises a shell, an air distribution plate, a gas heating assembly and a main fan, the air distribution plate is arranged in an inner cavity of the shell and divides the inner cavity of the shell into a drying chamber and a gas chamber from top to bottom, and the drying chamber and the gas chamber are arranged in the drying chamber. The roller screen is located in the drying chamber and arranged above the air distribution plate at intervals. The shell is provided with a feed port and a discharge port which are respectively communicated with the drying chamber, the feed port and the discharge port are arranged at an interval along the length direction of the shell, the feed port is positioned at the front end of the air distribution plate and positioned above the roller screen, and the discharge port is positioned at the tail end of the air distribution plate; the gas heating assembly, the main fan and the gas chamber are sequentially connected, and the heat source device is used for heating a screen shaft of the roller screen and a screen plate connected with the screen shaft. According to the utility model, materials with different particle sizes are separately dried, and meanwhile, oversize materials and undersize materials are synchronously dried, so that the drying efficiency is improved, and the coal quality is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal drying, and in particular relates to a fixed fluidized disturbance bed drying system. Background Art

[0002] At present, lignite has gradually become one of the main raw materials for power plants. Due to its high humidity (40% of its weight is water), the power output efficiency is relatively low. Lignite drying is an important process in the coal preparation industry. Lignite drying is of great significance in many aspects: the calorific value of lignite is usually 3000 kcal or less, which is relatively low. Through the drying process, its calorific value can be significantly increased, and even the calorific value can reach 4000 to 5000 kcal, thereby improving its efficiency and utilization as a fuel. Due to the high water content of lignite, the weight of lignite after drying is reduced, which can reduce energy consumption and costs during transportation. Lignite drying also helps to further improve combustion efficiency, reduce air pollution, reduce environmental pollution, and help achieve the goals of energy conservation and emission reduction and building an environmentally friendly industry.

[0003] Fluidized bed is a common machine for drying coal. It uses the porous air distribution plate at the bottom of the bed to let in drying air, so that the material to be dried above the bed is suspended, boiled and fluidized under the action of the drying air, so that the material is fully in contact with the drying air for drying. However, for lignite with high water content, the existing fluidized bed has low heat exchange efficiency and long drying time. At the same time, due to the drying thermal efficiency of the existing fluidized bed, the calorific value of the lignite after drying is generally low. Utility Model Content

[0004] Based on the problems existing in the prior art, the utility model provides a fixed fluidized turbulent bed drying system, which is a fixed fluidized turbulent bed system for drying high-moisture coal, which solves the technical problems of low fluidized bed heat exchange efficiency and long drying time for lignite or bituminous coal with high moisture content.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme.

[0006] According to the technical solution of the utility model, a fixed fluidized turbulent bed drying system is provided, including a fixed fluidized bed, a roller screen and a heat source device, wherein the fixed fluidized bed includes a shell and an air distribution plate, the inner cavity of the shell is provided with an air distribution plate, the air distribution plate divides the inner cavity of the shell into a drying chamber and an air chamber from top to bottom, and the roller screen is located in the drying chamber and is spaced above the air distribution plate. The shell has a feed port and a discharge port respectively connected to the drying chamber, the feed port and the discharge port are spaced along the length direction of the shell, the feed port is located at the front end of the air distribution plate and above the roller screen, and the discharge port is located at the end of the air distribution plate. It further includes a gas heating component and a main fan, the gas heating component, the main fan and the air chamber are connected in sequence, and the heat source device is used to heat the screen shaft and the screen plate of the roller screen.

[0007] Optionally, the heat source provided by the heat source device is high-temperature steam, the sieve shaft is a hollow shaft, and both ends of the hollow shaft have a first steam inlet and a first steam outlet respectively, and the heat source outlet of the heat source device is connected to the first steam inlet.

[0008] Optionally, the gas heating assembly includes a gas heater, the gas heater has a heating gas inlet, a heating gas outlet, a second steam inlet and a second steam outlet; the heating gas inlet, the heating gas outlet and the inlet of the main blower are connected in sequence. Further, the first steam outlet, the second steam inlet, the second steam outlet and the heat source inlet of the heat source device are connected in sequence.

[0009] Optionally, the fixed fluidized turbulent bed drying system also includes a dust collector, an exhaust fan and a chimney, and the gas heating assembly also includes a gas preheater. An exhaust port connected to the drying chamber is provided on the top of the shell, and the gas preheater has an external gas inlet, an external gas outlet, an exhaust steam inlet and an exhaust steam outlet; the exhaust port is connected to the inlet of the dust collector, and the gas outlet, exhaust steam inlet, exhaust steam outlet, exhaust gas fan and chimney of the dust collector are connected in sequence, the coal outlet of the dust collector is connected to the coal bunker, and the external gas inlet, external gas outlet and heating gas inlet are connected in sequence.

[0010] Optionally, the roller screen includes a feeding section and a drying section connected to the feeding section, and the feeding section and the drying section are arranged along the direction from the feeding port to the discharging port, wherein the feeding section is inclined and is arranged at an obtuse angle to the feeding section.

[0011] Optionally, an air-locking rotary feeder is provided at the feed inlet, a first air-locking discharger is provided at the discharge outlet, and a second air-locking discharger is provided between the end of the roller screen and the side wall of the shell. Optionally, a scraper is provided on the air distribution plate.

[0012] Compared with the prior art, the technical solution of the utility model has the following beneficial effects: a fixed fluidized turbulent bed drying system and method of the utility model screens materials into oversize and undersize through a roller screen, and the oversize is disturbed, tumbled, conveyed and dried by a screen shaft, a screen plate and hot gas, and the undersize is fluidized, conveyed and dried by an air distribution plate and hot gas, thereby achieving separate drying of materials of different particle sizes and simultaneous drying of the oversize and undersize, greatly improving drying efficiency, reducing drying time and improving coal quality.

[0013] Additional aspects and advantages of the present invention will be partially given in the following description, which will become apparent from the following description or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 It is a structural schematic diagram of a fixed fluidized turbulent bed drying system according to the utility model;

[0016] Figure 2 It is a left-side structural schematic diagram of a fixed fluidized turbulent bed drying system according to the utility model;

[0017] Figure 3 It is a top view structural schematic diagram of a fixed fluidized turbulent bed drying system according to the utility model;

[0018] Figure 4 The present invention is a process flow chart of a fixed fluidized turbulent bed drying system according to the present invention.

[0019] Description of each reference numeral in the accompanying drawings:

[0020] 1. Shell; 2. Air distribution plate; 3. Roller screen; 4. Main fan; 5. Air lock rotary feeder; 6. First air lock discharger; 7. Second air lock discharger; 8. Scraper conveyor; 9. Air regulating plate; 10. Outer box. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0022] Those skilled in the art will appreciate that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present utility model refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. In addition, the "connection" or "coupling" used here may include wireless connection or coupling. The term "and / or" used here includes any unit and all combinations of one or more associated listed items.

[0023] Those skilled in the art will appreciate that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the utility model belongs. It should also be understood that those terms such as those defined in general dictionaries should be understood to have the same meaning as the meaning in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0024] To facilitate the understanding of the embodiments of the present utility model, several specific embodiments will be further explained below with reference to the accompanying drawings, and each embodiment does not constitute a limitation on the embodiments of the present utility model.

[0025] The high-water-content low-rank coal involved in the utility model refers to low-rank coal, and the water-free ash-free high calorific value of this type of coal is relatively low. The low-rank coal in the utility model is characterized by the sum of carbon, hydrogen and oxygen accounting for more than 95% of organic matter, and low-rank coal mainly includes lignite and bituminous coal. Low-rank coal is a solid combustible mineral gradually formed by ancient plants buried underground and undergoing complex biochemical and physicochemical changes; lignite is a type of low-rank coal, which has the characteristics of high water content, high moisture content and low degree of metamorphism. Compared with lignite, bituminous coal has a higher degree of metamorphism, but it still belongs to the category of low-rank coal; bituminous coal is further subdivided into sub-bituminous coal and other sub-categories, among which sub-bituminous coal is a transitional coal between bituminous coal and lignite, and has a lower combustion calorific value (19306-26749kJ / kg). Anthracite and semi-anthracite are high- and low-rank coals with low volatile yield, high fixed carbon content, high density, high hardness, high ignition point, and no smoke when burning; anthracite is further divided into No. 01 anthracite (old anthracite), No. 02 anthracite (typical anthracite) and No. 03 anthracite (young anthracite); due to their low volatile yield and high fixed carbon content, anthracite and semi-anthracite are generally not suitable for the fixed fluidized turbulent bed drying process of the utility model. Since the fixed fluidized turbulent bed of the utility model adopts a double-layer drying process (separate drying of materials with different particle sizes, and simultaneous drying of the oversize and undersize materials), it is easy to cause anthracite and semi-anthracite to spontaneously combust or reduce the calorific value, thereby causing anthracite and semi-anthracite to deteriorate. Even if the existing fluidized bed dries anthracite and semi-anthracite, it also adopts the process of low-temperature drying and fluid drying.

[0026] A fixed fluidized turbulent bed drying system of the utility model includes a fixed fluidized bed, a roller screen and a heat source device. The fixed fluidized bed includes a shell and an air distribution plate. The inner cavity of the shell is provided with an air distribution plate. The air distribution plate divides the inner cavity of the shell into a drying chamber and an air chamber from top to bottom. The roller screen is located in the drying chamber and is spaced above the air distribution plate. Among them, the shell has a feed port and a discharge port respectively connected to the drying chamber. The feed port and the discharge port are spaced along the length direction of the shell. The feed port is located at the front end of the air distribution plate and above the roller screen, and the discharge port is located at the end of the air distribution plate; it further includes a gas heating component and a main fan. The gas heating component, the main fan and the air chamber are connected in sequence. The heat source device heats the screen shaft and the screen plate of the roller screen.

[0027] In one embodiment, the heat source provided by the heat source device is high-temperature steam, the sieve shaft is a hollow shaft, and both ends of the hollow shaft have a first steam inlet and a first steam outlet respectively, and the heat source outlet of the heat source device is connected to the first steam inlet.

[0028] In one embodiment, the gas heating component includes a gas heater, which has a heating gas inlet, a heating gas outlet, a second steam inlet and a second steam outlet; the heating gas inlet, the heating gas outlet and the inlet of the main fan are connected in sequence; the first steam outlet, the second steam inlet, the second steam outlet and the heat source inlet of the heat source device are connected in sequence.

[0029] In one embodiment, the fixed fluidized turbulent bed drying system also includes a dust collector, an exhaust fan and a chimney, and the gas heating assembly also includes a gas preheater. An exhaust port connected to the drying chamber is provided on the top of the shell, and the gas preheater has an external gas inlet, an external gas outlet, an exhaust steam inlet and an exhaust steam outlet; the exhaust port is connected to the inlet of the dust collector, and the gas outlet, exhaust steam inlet, exhaust steam outlet, exhaust gas fan and chimney of the dust collector are connected in sequence, the coal outlet of the dust collector is connected to the coal bunker, and the external gas inlet, external gas outlet and heating gas inlet are connected in sequence.

[0030] In one embodiment, the roller screen includes a feeding section and a drying section connected to the feeding section, and the feeding section and the drying section are arranged along the direction from the feeding port to the discharging port, wherein the feeding section is inclined and arranged at an obtuse angle to the feeding section.

[0031] In one embodiment, an air-locking rotary feeder is provided at the feed port, a first air-locking discharger is provided at the discharge port, and a second air-locking discharger is provided between the end of the roller screen and the side wall of the shell.

[0032] In one embodiment, a scraper is provided on the air distribution plate.

[0033] In one embodiment, an air regulating plate is provided in the air chamber.

[0034] The following is a further description and explanation of the present invention in conjunction with the accompanying drawings of the present invention.

[0035] See also Figures 1 to 3 As shown, an embodiment of the utility model provides a fixed fluidized turbulent bed drying system, which includes a fixed fluidized bed, a roller screen 3 and a heat source device, the fixed fluidized bed includes a shell 1, an air distribution plate 2, a gas heating component and a main fan 4, the inner cavity of the shell 1 is provided with an air distribution plate 2, the air distribution plate 2 divides the inner cavity of the shell 1 from top to bottom into a drying chamber and an air chamber (the upper part is the drying chamber, and the lower part is the air chamber), the roller screen 3 is located in the drying chamber and is spaced above the air distribution plate 2; the shell 1 has a feed port and a discharge port respectively connected to the drying chamber, the feed port and the discharge port are spaced along the length direction of the shell 1, the feed port is located at the front end of the air distribution plate 2 and above the roller screen 3, and the discharge port is located at the end of the air distribution plate 2; the gas heating component, the main fan 4 and the air chamber are connected in sequence, and the heat source device is used to heat the screen shaft and screen plate of the roller screen 3. The gap of the sieve plate of the roller screen 3 is set according to the law of material particle size distribution to screen the materials. For example, the gap of the sieve plate is 6mm. The wet coal enters the drying device from the feed port through the coal conveying system. The wet coal falls on the roller screen 3. The fine coal with a particle size less than or equal to 6mm will be gradually screened and fall onto the air distribution plate 2 at the bottom of the dryer. The fluidized medium is hot air or other inert gases. For example, the hot air heated by the gas heating component (the hot air temperature is 100°C to 180°C) is passed into the air chamber. The hot air passes through the air distribution plate 2 with a certain perforation rate to fluidize and dry the fine-grained fine coal with a particle size less than or equal to 6mm. The hot air directly contacts the fine coal for heat exchange. The air after heat exchange carries the water evaporated from the fine coal through the roller screen 3 to continue to dry the lump coal with a particle size greater than 6mm on the roller screen 3 (the particle size of the lump coal is not more than 50mm). At the same time, the sieve shaft and sieve plate of the roller screen 3 are heated by the heat source device to conduct heat exchange with the lump coal, thereby realizing drying and dehydration of the lump coal.

[0036] By applying the technical solution provided in the above-mentioned embodiment of the utility model, the material is screened into oversize and undersize by the roller screen 3, and the oversize is disturbed, tumbled, conveyed and dried by the screen shaft, screen plate and hot gas, and the undersize is fluidized, conveyed and dried by the air distribution plate 2 and hot gas. While achieving separate drying of materials of different particle sizes, the oversize and undersize are also dried synchronously, which greatly improves the drying efficiency, reduces the drying time and improves the quality of coal.

[0037] In some embodiments, the heat source provided by the heat source device is high-temperature steam, the sieve shaft is a hollow shaft, and the two ends of the hollow shaft have a first steam inlet and a first steam outlet, respectively. The heat source outlet of the heat source device is connected to the first steam inlet, and the high-temperature steam is passed into the sieve shaft to heat the sieve shaft and the sieve plate, thereby conducting heat exchange between the gaps of the sieve plate and the materials on the sieve plate. The high-temperature steam can be steam, flue gas, other waste heat or new energy such as steam generated by abandoned electricity generated by power plants, metallurgy, chemical industry and other units. The temperature of high-temperature steam is between 120°C and 200°C. Of course, the heat source can also be hot water or other energy sources that generate heat.

[0038] See also Figure 4 As shown, in some embodiments, the gas heating assembly includes a gas heater, and the gas heater has a heating gas inlet, a heating gas outlet, a second steam inlet and a second steam outlet; the heating gas inlet, the heating gas outlet and the inlet of the main fan 4 are connected in sequence; the first steam outlet, the second steam inlet, the second steam outlet and the heat source inlet of the heat source device are connected in sequence. For example, the temperature of the hot air for drying after being heated by the gas heater 5 is 100°C to 180°C, and the hot air enters the main fan 4 through the heating gas outlet, and enters the air chamber through the main fan 4; the high-temperature steam enters the screen shaft of the roller screen 3 from the first steam inlet through the pipeline, heats the screen shaft and the screen plate, and the water vapor flowing out of the first steam outlet flows into the gas heater through the first steam outlet to continue heating the air, and finally the high-temperature water vapor is converted into hydrophobicity and returns to the heat source device (power plant or boiler) through the second steam outlet.

[0039] See also Figure 4As shown, in some embodiments, the fixed fluidized turbulent bed drying system also includes a dust collector, an exhaust fan and a chimney, the gas heating assembly also includes a gas preheater, an exhaust port connected to the drying chamber is provided at the top of the shell 1, and the gas preheater has an external gas inlet, an external gas outlet, an exhaust steam inlet and an exhaust steam outlet; the exhaust port is connected to the inlet of the dust collector, the gas outlet, exhaust steam inlet, exhaust steam outlet, exhaust gas fan and chimney of the dust collector are connected in sequence, the coal outlet of the dust collector is connected to the coal bunker, and the external gas inlet, external gas outlet and heating gas inlet are connected in sequence. For example, ambient air enters the gas preheater through the external gas inlet and is heated by 10℃-30℃. The heated air enters the air heater through the external gas outlet and the heated gas inlet in turn to exchange heat with high-temperature water vapor. The air after heat exchange is heated to 100℃-180℃, flows through the main fan 4 and continues to be pressurized and enters the air chamber. The hot air passes through the air distribution plate 2 with a certain perforation rate to fluidize and dry the fine coal. The hot air directly contacts and exchanges heat with the fine coal. The air after heat exchange carries the water evaporated from the fine coal through the roller screen 3 to continue to dry the lump coal on the roller screen 3. At the same time, it is also heated by the screen shaft and screen plate on the roller screen 3. The air after heat exchange enters the dilute phase zone at the upper part of the drying chamber. At this time, the air temperature drops to 40℃-6 0℃, relative humidity 40%-60%, and carries moisture evaporated from wet coal and extremely fine coal powder, which is also commonly referred to as exhaust steam. Exhaust steam enters the dust collector (for example, the dust collector is a bag dust collector) through the exhaust port and the inlet of the dust collector. The fine coal powder is separated in the dust collector and collected through the coal outlet of the dust collector. The high-humidity and low-temperature exhaust gas enters the gas preheater through the gas outlet and exhaust steam inlet of the dust collector to exchange heat with the lower ambient air. In the gas preheater, part of the water vapor is condensed into water by releasing the latent heat of vaporization, and part of the water vapor is extracted together with the exhaust steam by the exhaust gas induced draft fan through the exhaust steam outlet and discharged to the atmosphere through the chimney. After filtration by the dust collector, the high-humidity air discharged to the atmosphere meets the indicators of environmental protection regulations. For the above structure and process flow, please refer to Figure 4 shown.

[0040] Overview Figure 4The process flow is as follows: the main body of the drying device is composed of a fixed fluidized bed and a roller screen, which is associated with a wet coal feed port, a dry coal discharge port and an exhaust steam outlet (the outlet of the mixed gas of moisture evaporated from the wet coal and extremely fine coal powder). The hot air from the gas heater is transported to the main body of the drying device composed of a fixed fluidized bed and a roller screen through the main fan for drying. The main body of the drying device composed of a free fixed fluidized bed and a roller screen. The wet hot steam from the main body of the drying device composed of a fixed fluidized bed and a roller screen is heated by the gas heater. The dry steam from the heat source device is used to adjust the process and drying purpose of the main body of the drying device. The mixed gas (exhaust steam) of moisture evaporated from the wet coal and extremely fine coal powder is dedusted by the dust collector, preheated by the gas preheater and mixed with air, and the hot clean gas (mixed gas obtained by mixing air with hot gas after dedusting by the dust collector) is provided to the gas heater for use, and the other tail gas (part of the water vapor and exhaust steam) is discharged through the chimney after the tail gas induced draft fan. The drainage process between the gas heater and the heat source device is as follows: the water vapor flowing out from the first steam outlet flows into the gas heater through the first steam outlet to continue heating the air, and finally the high-temperature water vapor is converted into drainage and returns to the heat source device (power plant or boiler) through the second steam outlet.

[0041] See also Figure 1 As shown, in some embodiments, the roller screen 3 includes a feed section and a drying section connected to the feed section, and the feed section and the drying section are arranged along the direction from the feed port to the discharge port, wherein the feed section is inclined and is arranged at an obtuse angle to the feed section, so that the material can fall along a certain inclined angle to avoid material accumulation.

[0042] In some embodiments, an air-locking rotary feeder 5 is provided at the feed port, a first air-locking discharger 6 is provided at the discharge port, and a second air-locking discharger 7 is provided between the end of the roller screen 3 and the side wall of the housing 1. The wet coal enters the drying device through the air-locking rotary feeder 5 and falls on the roller screen 3. As the roller screen 3 rotates continuously, the fine coal with a particle size less than or equal to 6 mm will fall on the air distribution plate 2, and the lump coal with a particle size greater than 6 mm continues to move along the roller screen 3 to the other end of the housing 1. Since the hollow screen shaft is continuously heated by high-temperature steam passing through the screen shaft and the heat-conducting screen plate, the lump coal on the roller screen 3 is continuously heated by the hot air passing through the air distribution plate 2 and the roller screen 3. The lump coal is continuously rolled during the movement on the roller screen 3, which increases the gap between the lump coals and is more conducive to the heating of the lump coal by the hot air. The lump coal after drying falls into the second air lock discharger 7. The second air lock discharger 7 can ensure that the hot air in the housing 1 will not leak from the place where the lump coal falls. The hot air can only pass through the screen gap of the roller screen 3 to dry the lump coal. The fine coal that falls on the air distribution plate 2 is continuously fluidized and dried by the hot air passing through the air distribution plate 2. The dried fine coal is mixed with the lump coal that falls from the second air lock discharger 7 and enters the first air lock discharger 6 together. The first air lock discharger 6 rotates to drop the dried coal onto the conveyor belt outside the drying device. The setting of the first air lock discharger 6 not only cuts off the flow between the drying device and the external environment, but also ensures that the dried coal is transported from the drying device to the outside of the dryer.

[0043] See also Figure 1 As shown, in some embodiments, a scraper 8 is provided on the air distribution plate 2. The fine coal falling on the air distribution plate 2 is continuously fluidized and dried by the hot air passing through the air distribution plate 2. By installing a scraper 8 with a circulating disturbance above the air distribution plate 2, both efficient drying of fine-particle coal and rapid transportation of fine-particle coal to the outlet of the drying device are achieved. Due to the continuous disturbance of the fine coal by the scraper 8, defects such as agglomeration, channeling and short circuit of fine-particle coal in the fluidized drying process are prevented.

[0044] See also Figure 1 As shown, in some embodiments, an air regulating plate 9 is installed in the air chamber, and air is evenly supplied to the air distribution plate 2 through the air regulating plate 9. There are multiple air regulating plates 9, and the multiple air regulating plates 9 are spaced apart from each other along the length direction of the air chamber and evenly distributed in the air chamber, dividing the air chamber into multiple isobaric air chambers, wherein the windward area of ​​the air regulating plate 9 and the airflow direction are adjusted by adjusting the inclination angle of the air regulating plate 9, thereby adjusting the pressure in each air chamber.

[0045] See also Figures 1 to 3 As shown, in some embodiments, the fixed fluidized turbulent bed drying system further includes an outer box 10, which is disposed on the outside of the housing 1 and the main fan 4, and the inner devices thereof are protected by the outer box 10.

[0046] In this embodiment, the heat source used in the fixed fluidized turbulent bed drying system is high-temperature steam, which can be exhaust from a power plant, or generated by a pulverized coal steam boiler that burns fine coal collected by a bag filter, or generated by heating water from abandoned electricity from new energy sources. The high-temperature steam is mainly used to heat pure air from the environment through a gas heater. The temperature of the heated hot air for drying is between 100°C and 180°C. The high-temperature steam is passed into the hollow screen shaft of the roller screen 3 to heat the screen shaft and the screen plate. The screen plate then heats the coal blocks between the gaps of the screen plate and on the screen plate and the fluidized air flowing through. The water vapor flowing out of the hollow screen shaft of the roller screen 3 enters the gas heater to continue heating the air, and finally the high-temperature water vapor is converted into hydrophobic water and returns to the power plant or boiler.

[0047] The ambient air is drawn into the gas preheater by the main fan to exchange heat with the dried exhaust gas, which can raise the temperature of the ambient air by 10-30°C. The heated air is drawn into the gas heater by the main fan 4 to exchange heat with the high-temperature water vapor in the gas heater. The air after heat exchange is heated to 100°C-180°C, flows through the main fan 4 and continues to be pressurized and enters the air chamber from one end of the shell 1. An air regulating plate 9 is installed in the air chamber. By adjusting the air regulating plate 9, air can be evenly supplied to the air distribution plate 2. The hot air passes through the air distribution plate 2 with a certain perforation rate to fluidize and dry the fine-grained coal with a particle size of less than 6mm in the fluidized bed. The hot air directly contacts and exchanges heat with the coal. The air after heat exchange carries the water evaporated from the coal through the roller screen 3 and continues to screen the fine-grained coal with a particle size of 6m on the screen. The lump coal with a diameter of more than m and less than 25 mm is dried and is also heated by the sieve plate on the roller screen 3. The air after heat exchange enters the dilute phase zone at the top of the dryer. At this time, the air is cooled to 40-60℃ and the relative humidity is 40-60%. It carries moisture evaporated from the wet coal and extremely fine coal powder, which is usually also called exhaust steam. The exhaust steam is drawn into the bag filter by the fan, and the fine coal powder is separated and collected in the bag filter. The high-humidity and low-temperature exhaust gas is further drawn into the gas preheater for heat exchange with the lower ambient air. In the gas preheater, part of the water vapor releases the latent heat of vaporization and condenses into water. Part of the water vapor and the exhaust steam are discharged to the atmosphere through the fan and the chimney. After filtering by the bag filter, it can be ensured that the high-humidity air discharged to the atmosphere meets the indicators of environmental protection regulations.

[0048] Among them, the wet coal enters the housing 1 through the air-locking rotary feeder 5 and falls on the roller screen 3. As the roller screen 3 rotates continuously, the fine coal with a particle size of less than 6 mm will fall onto the air distribution plate 2, and the lump coal with a particle size of more than 6 mm and less than 25 mm continues to move along the roller screen 3 to the other end of the housing 1. Since the hollow roller is continuously heated by high-temperature steam to heat the roller and the screen plate, the lump coal on the roller screen 3 is continuously heated by the hot air, roller and screen plate introduced from the fluidized bed. The lump coal is continuously rolled during the movement on the roller screen 3, increasing the gap between the lump coals, and more effectively heating the lump coal with hot air. The lump coal after drying falls into the second air-locking discharger 7, which can ensure that the hot air in the fluidized bed will not leak from the lump coal drop point, and force the hot air to pass through the gap of the roller screen 3 to dry the lump coal. The front end 9-11 rollers of the roller screen 3 can be designed to fall at a certain angle. The fine coal with a particle size of less than 6 mm falling into the fluidized bed is continuously fluidized and dried by hot air passing through the air distribution plate 2. The scraper 8 arranged on the air distribution plate continuously pushes the fine coal from the feeding end to the dried discharge end. The continuous disturbance of the fine coal by the scraper 8 also avoids the defects of the fine coal fluidization drying process. The dried fine coal is mixed with the lump coal falling from the second air lock discharger 7 and enters the first air lock discharger 6 together. The rotary discharger rotates and drops the dried coal onto the conveyor belt outside the dryer. The setting of the first air lock discharger 6 cuts off the flow between the fluidized bed and the environment and ensures that the dried coal is transported from the dryer to the outside of the dryer.

[0049] In some embodiments, the system for drying high-moisture coal in a fixed fluidized turbulent bed also includes exhaust gas purification treatment, in which the exhaust steam that passes through the roller screen 3 and undergoes heat exchange is introduced into the dust collector through the exhaust port, and after the particulate material is separated and collected by the dust collector, the high-humidity and low-temperature exhaust steam is further transported to the gas preheater for heat exchange with external gas at a lower temperature. In the gas preheater, part of the water vapor releases latent heat of vaporization and condenses into water, and part of the water vapor is extracted together with the exhaust steam through the exhaust draft fan and discharged through the chimney.

[0050] The gas that passes through the roller screen 3 and undergoes heat exchange enters the dilute phase area at the top of the drying chamber. At this time, the gas is cooled to any temperature between 40℃ and 60℃, with a relative humidity of 40-60%, and carries the water evaporated from the wet coal and extremely fine coal powder, which is usually called exhaust steam. Figure 4As shown in the specific embodiment, 20 tons of lignite with a particle size of 0-13mm and a moisture content of 17.88% are dried in a fixed fluidized turbulent bed drying system. The test lignite enters the drying device from the feed port at the top of the shell 1 through the coal conveying system. The lignite falls on the screen shaft with a roller screen 3, and the lignite with a fine particle size below -6mm will be gradually screened and dropped to the lower part of the drying chamber. The hollow screen shaft is passed with high-temperature steam of about 152°C, and the water vapor heats the screen shaft and the screen plate by conduction. The screen shaft and the screen plate then conduct heat exchange with the lump coal on the screen, and the hot air rising from the air distribution plate 2 heats the lump coal. At the same time, a large amount of hot air of about 103.6°C is introduced into the lower air chamber of the drying device to directly contact the fine-grained coal for fluidized drying. The temperature in the fluidized bed is about 35.9°C. A circulating turbulent scraper 8 is installed above the air distribution plate 2. Under the action of the scraper 8, the fine-grained coal is quickly transported to the discharge port of the drying device. In the process of the lump coal with a particle size of more than 6mm on the roller screen 3 being continuously sent from the front end of the shell 1 to the rear end of the shell 1, it is not only subjected to conduction heat exchange by the screen shaft and the screen plate, but also subjected to convection heat exchange by the hot air flowing out of the air distribution plate, and finally the lump coal is dried and dehydrated. Since the drying temperature, the rotation speed of the roller screen, and the speed of the disturbance scraper are all adjustable, the synchronous dehydration of the fine coal and the lump coal is achieved. After the drying is completed, the mixture of fine coal and lump coal at 34.5℃ and 14.30% moisture falls from the discharge port and is transported to the coal bin. A very small part of the fine material enters the dust collector with the 36.8℃ airflow, and the fine material separated by the dust collector is recovered as a product. The relevant test data are shown in Table 1, and the test data calculation results are shown in Table 2. Table 1 is a record table of the original experimental data, and Table 2 is a drying performance calculation table based on the experimental data in Table 1.

[0051]

[0052]

[0053] Table 1

[0054] Serial number name unit Working Condition I 1 Coal input Ton / H 20 2 Lignite moisture ％ 17.88 3 Coal moisture ％ 14.30 4 Water removal rate ％ 3.58 5 Water removal ton 0.84 6 Heating hot air temperature ℃ 103.6 7 Exhaust temperature ℃ 36.8 8 Ambient temperature ℃ 0 9 Feed temperature ℃ 0 10 Discharge temperature ℃ 34.5 11 Hot air releases heat in the drying device Wan KJ 364.41 12 Total heat required to dry coal Wan KJ 1162.65 13 Hot air volume (mass) ㎏ / H 212589

[0055] Table 2

[0056] In summary, the present invention provides a fixed fluidized turbulent bed drying system, which has the following beneficial effects:

[0057] (1) The upper part of the drying device is a roller screen composed of a hollow screen shaft with a screen plate, and the lower part is a fixed fluidized bed with a disturbance device, so that two different particle sizes of coal can be dried simultaneously through two different paths, which not only achieves efficient dehydration of high-water-content low-rank coal, but also can make full use of hot air to dry mixed particle size coal, thereby improving coal quality;

[0058] (2) Since the drying temperature, roller screen speed, and disturbance scraper speed are all adjustable, the water removal of fine coal and lump coal can be achieved simultaneously while meeting the demand for adjusting different water removal rates;

[0059] (3) Both fine coal and lump coal fall from the end of the drying device and are transported to the coal bunker. A very small amount of fine material enters the dust collector with the air flow. The fine material separated by the dust collector is recovered as a product, and the high-humidity and low-temperature exhaust gas can be used by the gas preheater to exchange heat with the lower ambient air. No pollutants are emitted during the drying process, and the high-level steam can be recycled as a heat source, which is energy-saving and environmentally friendly.

[0060] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily necessary for implementing the present utility model.

[0061] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0062] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A fixed fluidized turbulent bed drying system, characterized in that: It includes a fixed fluidized bed, a roller screen and a heat source device. The fixed fluidized bed includes a shell and an air distribution plate. The air distribution plate is provided in the inner cavity of the shell. The air distribution plate divides the inner cavity of the shell into a drying chamber and an air chamber from top to bottom. The roller screen is located in the drying chamber and is spaced above the air distribution plate.

2. The fixed fluidized disturbed bed drying system according to claim 1, characterized in that: The shell has a feed port and a discharge port respectively connected to the drying chamber, the feed port and the discharge port are spaced apart along the length direction of the shell, the feed port is located at the front end of the air distribution plate and above the roller screen, and the discharge port is located at the end of the air distribution plate.

3. The fixed fluidized disturbed bed drying system according to claim 2, characterized in that: It further comprises a gas heating component and a main fan, wherein the gas heating component, the main fan and the air chamber are connected in sequence, and the heat source device is used to heat the screen shaft of the roller screen and the screen plate connected to the screen shaft.

4. The fixed fluidized disturbed bed drying system according to claim 3, characterized in that: The heat source provided by the heat source device is high-temperature steam. The sieve shaft is a hollow shaft. Both ends of the hollow shaft are respectively provided with a first steam inlet and a first steam outlet. The heat source outlet of the heat source device is connected to the first steam inlet.

5. The fixed fluidized turbulent bed drying system according to claim 4, characterized in that: The gas heating assembly includes a gas heater having a heating gas inlet, a heating gas outlet, a second steam inlet, and a second steam outlet; The heating gas inlet, the heating gas outlet and the inlet of the main blower are connected in sequence; The first steam outlet, the second steam inlet, the second steam outlet, and the heat source inlet of the heat source device are sequentially connected.

6. The fixed fluidized disturbed bed drying system according to claim 5, characterized in that: The fixed fluidized turbulent bed drying system also includes a dust collector, an exhaust fan and a chimney. The gas heating component also includes a gas preheater. The top of the shell is provided with an exhaust port connected to the drying chamber. The gas preheater has an external gas inlet, an external gas outlet, an exhaust steam inlet and an exhaust steam outlet.

7. The fixed fluidized disturbed bed drying system according to claim 6, characterized in that: The exhaust port is connected with the inlet of the dust collector, the gas outlet of the dust collector, the exhaust steam inlet, the exhaust steam outlet, the exhaust gas induced draft fan and the chimney are connected in sequence, the coal outlet of the dust collector is connected with the coal bunker, and the external gas inlet, the external gas outlet and the heating gas inlet are connected in sequence.

8. The fixed fluidized disturbed bed drying system according to claim 4, characterized in that: The roller screen comprises a feeding section and a drying section connected to the feeding section, wherein the feeding section and the drying section are arranged along the direction from the feeding port to the discharging port, wherein the feeding section is inclined and is arranged at an obtuse angle to the feeding section.

9. The fixed fluidized turbulent bed drying system according to claim 4, characterized in that: An air-locking rotary feeder is arranged at the feed inlet, a first air-locking discharger is arranged at the discharge outlet, and a second air-locking discharger is arranged between the end of the roller screen and the side wall of the shell.

10. The fixed fluidized disturbed bed drying system according to claim 1, characterized in that: A scraper is arranged on the air distribution plate.

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