A slurry stream pulverizing dryer

Abstract

The present application relates to material crushing and drying technical field, specifically to a kind of slurrying steam flow crushing and drying machine, including sequentially interconnected storage cylinder, heater, air grinder and drying collector, storage cylinder is connected with inlet slurry pump and inlet slurry pipe, inlet slurry pump is connected storage cylinder and heater by inlet slurry pipe, to send material in storage cylinder into heater and heat;Air grinder includes shell, main shaft, rotating target, multiple la val nozzles, grading screen and the first drive mechanism for driving main shaft rotation, main shaft is rotatably longitudinally arranged in shell, and main shaft is worn fixed rotating target and grading screen, grading screen is located above rotating target, multiple la val nozzles are arranged around the side of rotating target, and each la val nozzle is connected with the outlet of heater via steam slurry pipe;The position of shell above grading screen is provided with discharge port, discharge port is connected with drying collector via discharge pipe, and drying collector is provided with exhaust mechanism for exhausting discharge pipe.Energy saving and low cost, high crushing efficiency.

Description

Technical Field

[0001] This invention relates to the field of material pulverization and drying technology, specifically to a slurry steam flow pulverizer and dryer. Background Technology

[0002] Air jet milling utilizes the energy of compressed air or superheated steam to cause materials to impact, collide, and rub against each other, achieving ultrafine grinding. Its products are widely used in industries such as chemicals, ceramics, coatings, electronic materials, and pharmaceuticals. Currently, the main type of air jet milling equipment on the market is the fluidized bed air jet mill. This type has several nozzles arranged in two or three dimensions inside the mill's main casing. The airflow is accelerated through the nozzles, carrying the material to a single point. The material collides and rubs against each other at high speed, achieving grinding. The airflow expands, causing the material to suspend in a fluidized bed, where grinding occurs through collisions and friction. However, this type of particle-to-particle collision grinding has low grinding force and poor grinding effect.

[0003] Later, target-type fluidized bed air jet mills emerged, such as the air jet mill disclosed in patent document CN2751891Y. In this type, air jets ejected from nozzles propel material floating in the casing towards a target, where the collision between the target and the material achieves the purpose of pulverization. However, this type of air jet mill still has significant shortcomings:

[0004] First, the grinding efficiency of steam jet mills for micron-level materials is lower than that of wet grinding in sand (bead) mills. If wet-ground materials need to be dried into powder before entering the steam jet mill, this increases the energy consumption for drying. If dry-ground materials are fed into the steam jet mill, the materials still have a high moisture content, i.e., they are in a wet powder state. The materials are damp before grinding and will stick together, making them unable to be attracted by the airflow to impact the target plate. Therefore, the materials must be dried before impact grinding. Although they are in a dry state after grinding, the role of steam is only to provide potential energy; the heat is not used for drying. Therefore, the energy consumption and cost of material grinding and drying in steam jet mills are high.

[0005] Secondly, in a steam mill, the material being pulverized is stationary before entering the supersonic nozzle. It needs to be drawn in by the back pressure of the nozzle and accelerated by the steam flow. Its speed and potential energy are lower than those of the steam flow, and the flow rate of the steam flow is also significantly reduced. When the material is placed in the casing, it is driven by the steam flow to impact the target, thus greatly reducing the force of the impact.

[0006] Third, the nozzles of existing air jet mills are arranged in a horizontal straight line. Due to the space limitation of the flat plate on which the nozzles are installed, it is difficult to make the mill large-scale and the grinding scale is limited.

[0007] Fourth, the materials in existing steam flow mills either collide with materials of the same hardness or with a stationary target, and the impact speed and intensity are limited.

[0008] Fifth, existing steam flow mills all have separate classifying wheels for the powder inside the machine chamber, and the bearings of the classifiers are mostly placed in high-temperature and harsh environments with the powder, resulting in a very short service life for the bearings. Summary of the Invention

[0009] In view of the above-mentioned technical problems existing in the prior art, the present invention provides a slurry steam flow pulverizer and dryer.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A slurry steam jet pulverizer and dryer is provided, comprising a slurry storage tank, a heater, an air mill and a dryer collector connected in sequence. The slurry storage tank is connected to a slurry inlet pump and a slurry inlet pipe. The slurry inlet pump is connected to the inlet of the slurry storage tank and the heater through the slurry inlet pipe to transport the slurry material in the slurry storage tank into the heater for heating.

[0012] The air mill includes a casing, a main shaft, a rotating target, multiple Laval nozzles, a classifying screen, and a first drive mechanism for driving the main shaft to rotate. The main shaft is rotatably and longitudinally arranged inside the casing, and the rotating target and classifying screen are fixed through the main shaft. The classifying screen is located above the rotating target. Multiple Laval nozzles are arranged around the circumference of the rotating target, and each Laval nozzle is connected to the outlet of the heater via a steam pipe. The casing has a discharge port located above the classifying screen. The discharge port is connected to a drying and collecting machine via a discharge pipe. The drying and collecting machine is equipped with an exhaust mechanism for drawing air from the discharge pipe.

[0013] Specifically, the heater includes an upper tube box, an upper tube sheet, a heat exchange cylinder, multiple heat exchange tubes, a lower tube sheet, and a lower tube box. The upper and lower tube sheets are fixed to the two ends of the heat exchange cylinder, thus forming a shell-side space. The heat exchange cylinder is equipped with a heating mechanism for circulating hot air, steam, or heat transfer oil into the shell-side space. The upper tube box is fixed to the upper tube sheet, and the two together form the upper tube-side space. The slurry inlet pipe connects to the upper tube-side space. The lower tube box is fixed to the lower tube sheet, and the two together form the lower tube-side space. The steam-slurry pipe connects to the lower tube-side space. Multiple heat exchange tubes are arranged side by side in the shell-side space, and the two ends of the multiple heat exchange tubes are fixed to the upper and lower tube sheets, respectively, and are connected to the upper and lower tube-side spaces, respectively.

[0014] Specifically, the rotating target has teeth on its periphery, and the Laval nozzle is arranged at an angle relative to the radial direction of the rotating target and is arranged to oppose the direction of the rotating target.

[0015] Specifically, the grading screen includes a support block and multiple screen bars arranged circumferentially around the support block, with the main shaft passing through the fixed support block.

[0016] Specifically, the casing is cylindrical, with multiple Laval nozzles arranged circumferentially on the side wall of the casing, and the ends of multiple screen bars of the grading screen extending to the inner wall of the casing; a baffle plate is installed on the inner wall of the casing above the grading screen, and the length of the baffle plate is greater than the distance between the screen bars and the inner wall of the casing.

[0017] Specifically, the machine housing has an internal shaft support assembly for supporting the spindle. The shaft support assembly includes a bracket, a bearing housing, and a bearing. The bracket is fixed to the machine housing, the bearing housing is fixed to the bracket, the spindle passes through the bearing housing, and the bearing is installed inside the bearing housing and clamps the spindle. The bracket is a partition plate that divides the internal space of the machine housing into upper and lower layers, and the spindle passes through the lower part of the bracket. The first drive mechanism includes a main motor, a drive wheel, a driven wheel, and a transmission belt. The drive wheel is fixed to the output shaft of the main motor, the driven wheel is fixed to the lower end of the spindle, and the drive wheel and the driven wheel are connected by a transmission belt.

[0018] Specifically, the bearing housing includes a housing body, an upper cover, and a lower cover. The bearing is held in the housing body. The upper cover and the lower cover are fixed to the two ends of the housing body, respectively. The housing body is provided with a lubricating oil passage. The upper cover is provided with an oil inlet pipe that connects to one end of the lubricating oil passage. The lower cover is provided with an oil outlet pipe that connects to the other end of the lubricating oil passage. The lubricating oil carries away the heat of the bearing and enters the lubricating oil cooler through the oil outlet pipe for recycling.

[0019] Specifically, the support is arranged at an angle inside the housing, and a coarse particle outlet is provided on the inner wall of the housing near the lower part of the support; a coarse particle return mechanism is also provided on the side of the housing, which is connected to the coarse particle outlet to transport the coarse particles to the Laval nozzle or the heating furnace.

[0020] Specifically, the coarse particle return mechanism includes a screw feeder, a bucket elevator, and a return hopper. The screw feeder is connected to the coarse particle outlet on the side wall of the machine casing. The two ends of the bucket elevator are connected to the screw feeder and the return hopper, respectively. The return hopper is annular, and the bottom of the return hopper is equipped with multiple return ports that are connected to multiple Laval nozzles. The return ports are equipped with return valves.

[0021] Specifically, the return hopper is equipped with a scraping assembly, which includes a support frame, multiple scrapers, guide wheels, and a second drive mechanism. The support frame can rotate around the outside of the machine housing, and the multiple scrapers are installed on the support frame and embedded in the return hopper. The outside of the machine housing is provided with a guide ring, and the guide wheel is installed on the support frame and rolls in cooperation with the guide ring. The second drive mechanism includes a scraping motor and transmission gears, and the scraping motor drives the support frame to rotate through the transmission gears.

[0022] The beneficial effects of this invention are:

[0023] The slurry steam jet pulverizer and dryer of the present invention has the following advantages compared with the prior art:

[0024] 1. It can directly feed wet slurry into the mill after heating, thus saving the drying process before grinding, saving energy and reducing costs.

[0025] 2. After the material is heated, the moisture in the material turns into steam. The material particles are mixed in with the steam and accelerated through the nozzle. During the collision with the rotating target, all the work is done by impacting the target at the highest speed after spraying. The rigid collision with the rotating target results in a large impact force and high crushing efficiency. Compared with the elastic collision between traditional sprayed particles and suspended particles, the efficiency is even higher.

[0026] 3. The number of nozzles can be greatly increased by increasing the diameter of the rotating target, which is beneficial for the large-scale development of the equipment.

[0027] 4. The circular motion of the rotating target increases the collision speed and improves the crushing efficiency.

[0028] 5. It is easy to control the particle size (fineness grade) by adjusting the spindle speed and the suction force of the discharge pipe. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the slurry steam jet pulverizer and dryer in the embodiment.

[0030] Figure 2 This is a schematic diagram of the heater in the embodiment.

[0031] Figure 3 This is a schematic diagram of the air mill in the embodiment.

[0032] Figure 4 This is a schematic diagram of the grading sieve in the embodiment.

[0033] Figure 5 This is a schematic diagram of the rotating target and Laval nozzle in the embodiment.

[0034] Figure 6 This is a schematic diagram of the shaft support assembly and the main shaft in the embodiment.

[0035] Figure label:

[0036] 1. Casing; 11. Discharge port; 12. Discharge pipe; 13. Air inlet; 14. Baffle plate; 15. Coarse particle outlet; 16. Guide ring.

[0037] Spindle 2;

[0038] Target rotation 3, teeth 31;

[0039] Laval nozzle 4, steam slurry pipe 41;

[0040] Grading screen 5, support block 51, screen bar 52;

[0041] First drive mechanism 6, main motor 61, drive wheel 62, driven wheel 63, transmission belt 64;

[0042] 71 bracket, 72 bearing housing, 721 housing body, 7211 lubrication oil passage, 722 upper cover, 7222 oil inlet pipe, 723 lower cover, 7231 oil outlet pipe, 73 bearing, 74 reinforcing rib;

[0043] 81. Screw feeder, 82. Bucket elevator, 83. Return hopper, 84. Return valve, 85. Support frame, 86. Scraper, 87. Guide wheel, 88. Scraper motor, 89. Transmission gear;

[0044] 91. Slurry storage tank; 92. Slurry inlet pump; 93. Slurry inlet pipe;

[0045] Heater 10, upper tube box 101, upper tube sheet 102, heat exchange cylinder 103, heat exchange tube 104, lower tube sheet 105, lower tube box 106;

[0046] Air mill 01, dryer and collector 02;

[0047] Heating mechanism 03, burner 031, hot air furnace 032, induced draft fan 033. Detailed Implementation

[0048] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0049] The slurry steam jet pulverizer and dryer of this embodiment, such as Figures 1 to 6 As shown, the system includes a slurry storage tank 91, a heater 10, an air mill 01, and a dryer / collector 02 connected sequentially from left to right. The slurry storage tank 91 is used to store wet mud material. The slurry storage tank 91 is connected to a slurry inlet pump 92 and a slurry inlet pipe 93. The slurry inlet pump 92 is preferably a plunger pump. The slurry inlet pump 92 is connected to the inlet of the slurry storage tank 91 and the heater 10 through the slurry inlet pipe 93 to transport the slurry material in the slurry storage tank 91 into the heater 10 for heating. The solid content of the slurry can be from 5% to 85%, preferably from 50% to 70%.

[0050] The heater 10 includes an upper tube box 101, an upper tube sheet 102, a heat exchange cylinder 103, multiple heat exchange tubes 104, a lower tube sheet 105, and a lower tube box 106. The upper tube sheet 102 and the lower tube sheet 105 are respectively fixed to the two ends of the heat exchange cylinder 103, thereby forming a shell-side space. The upper tube box 101 is fixed to the upper tube sheet 102, and the two together form the upper tube-side space. The slurry inlet pipe 93 connects to the upper tube-side space. The lower tube box 106 is fixed to the lower tube sheet 105, and the two together form the lower tube-side space. Multiple heat exchange tubes 104 are arranged side by side in the shell-side space, and the two ends of the multiple heat exchange tubes 104 are respectively fixed to the upper tube sheet 102 and the lower tube sheet 105, and respectively connected to the upper tube-side space and the lower tube-side space. The heat exchanger shell 103 is equipped with a heating mechanism 03 for circulating hot air into the shell-side space. The heating mechanism 03 includes a burner 031, a hot air furnace 032, and an induced draft fan 033. The burner 031 and the hot air furnace 032 are connected to the inlet at the bottom of the heat exchanger shell 103. Under the action of the induced draft fan 033 at the outlet at the top of the heat exchanger shell 103, the hot air generated by the combustion furnace is passed through the shell-side space to heat the heat exchange tubes 104. In practice, the heating mechanism 03 can also be replaced with a mechanism for circulating steam or heat transfer oil into the shell-side space, which can also serve the purpose of heating the heat exchange tubes 104. During use, the feed pump 92 transports the material in the storage tank 91 to the heater 10, and outputs it sequentially through the upper tube space, heat exchange tube 104, and lower tube space of the heater 10. In this way, the material is heated to 150-500°C by the tube wall of the heat exchange tube 104, preferably in the low temperature range of 150-300°C. The moisture in the material evaporates into steam, and the material particles are mixed in the steam to form a fluid output.

[0051] In this embodiment, the air mill 01 includes a housing 1, a main shaft 2, a rotating target 3, multiple Laval nozzles 4, a classifying screen 5, and a first drive mechanism 6 for driving the main shaft 2 to rotate. The main shaft 2 is rotatably and longitudinally arranged inside the housing 1, and passes through the center of the fixed rotating target 3 and the classifying screen 5. The classifying screen 5 is located above the rotating target 3. The multiple Laval nozzles 4 are arranged around the periphery of the rotating target 3, and each Laval nozzle 4 is connected to the lower tube space outlet of the heater 10 via a high-pressure steam pipe 41. A discharge port 11 is provided at the top position above the classifying screen 5. The discharge port 11 is connected to a drying and collecting machine 02 via a discharge pipe 12. The drying and collecting machine 02 is provided with an exhaust mechanism for drawing air from the discharge pipe 12. The drying and collecting machine 02 can be a bag filter dust collector of the prior art.

[0052] During operation, after the material is heated by the heater 10, the mixture of steam and material particles is transported to each Laval nozzle 4 via the high-pressure steam pipe 41. The Laval nozzle 4 sprays the material at supersonic speed onto the rotating target 3. The material impacts and collides with the rotating target 3, crushing it. Fine particles float upwards with the steam, pass through the grading screen 5, and flow into the dryer / collector 02 for drying and recycling. Coarser particles fall to the bottom of the casing 1. Thus, after heating, the particles in the material are accelerated by the nozzles and collide with the rotating target 3. All the work done during this collision occurs at the highest speed after spraying, resulting in a high impact force and high crushing efficiency due to the rigid collision with the rotating target 3. This is even more efficient than the elastic collision between traditional sprayed particles and suspended particles. To balance the air pressure inside the casing 1, air inlets 13 are provided on the side wall of the casing 1.

[0053] In this embodiment, the rotating target 3 has teeth 31 on its circumference. The Laval nozzle 4 is arranged at an angle relative to the radial direction of the rotating target 3 and is arranged to oppose the direction of rotation of the rotating target 3. In this way, the collision velocity of the material with the rotating target 3 is approximately equal to the spray velocity of the Laval nozzle 4 plus the circumferential velocity of the rotating target 3, resulting in a large impact force and higher crushing efficiency. It should be noted that the Laval nozzle 4 is existing technology, which can change the velocity of the fluid due to the change in the spray cross-sectional area, allowing the fluid to accelerate from subsonic to sonic speeds, and even to transonic speeds. Therefore, this type of horn-shaped nozzle is called a transonic nozzle.

[0054] In this embodiment, the grading screen 5 includes a support block 51 and multiple screen bars 52 arranged circumferentially around the support block 51. The main shaft 2 passes through and is fixed to the support block 51. The casing 1 is cylindrical, and multiple Laval nozzles 4 are arranged circumferentially on the side wall of the casing 1. The ends of the multiple screen bars 52 of the grading screen 5 extend to near the inner wall of the casing 1. A baffle plate 14 is provided on the inner wall of the casing 1 above the grading screen 5, and the length of the baffle plate 14 is greater than the distance between the screen bars 52 and the inner wall of the casing 1. The purpose is to block medium-sized particles by the screen bars 52 of the grading screen 5 and allow them to fall along the inner wall of the casing 1 under centrifugal force. When they fall to the Laval nozzles 4, they are impacted again by the ejected fluid and strike the rotating target 3 for secondary crushing. Some coarser particles that are not impacted by the nozzles for secondary crushing fall to the bottom of the casing 1 and are lifted back for tertiary crushing, which will be described in detail later. As can be seen from the above, in practice, particle size (particle coarseness level) can be controlled by adjusting the rotation speed of the main shaft 2, the number and diameter of the screen bars 52, or the suction force of the discharge pipe 12. The higher the rotation speed of the main shaft 2, the greater the crushing impact force, the higher the degree of crushing, and the greater the degree of material crushing. At the same time, the higher the rotation speed of the grading screen 5, the higher the efficiency of particle blocking, and the smaller particles can also be returned for secondary crushing to achieve the nanoscale crushing requirement. The greater the suction force, the more coarser particles will also be attracted up. Therefore, controlling the wind force can prevent particles that have not yet reached the required size from being sucked up.

[0055] In this embodiment, the housing 1 has an internal shaft support assembly for supporting the spindle 2. The shaft support assembly includes a bracket 71, a bearing seat 72, and a bearing 73. The bracket 71 is fixed to the housing 1, the bearing seat 72 is fixed to the bracket 71, the spindle 2 passes through the bearing seat 72, and the bearing 73 is installed inside the bearing seat 72 and holds the spindle 2 in place. The bracket 71 is a partition plate that divides the internal space of the housing 1 into upper and lower layers. A reinforcing rib 74 is provided between the bracket 71 and the housing 1, and the spindle 2 passes under the bracket 71. The first drive mechanism 6 includes a main motor 61, a drive wheel 62, a driven wheel 63, and a transmission belt 64. The drive wheel 62 is fixed to the output shaft of the main motor 61, and the driven wheel 63 is fixed to the lower end of the spindle 2. The drive wheel 62 and the driven wheel 63 are connected by the transmission belt 64. The bearing housing 72 includes a housing body 721, an upper cover 722, and a lower cover 723. The bearing 73 is fitted into the housing body 721. The upper cover 721 and the lower cover 722 are respectively fixed to the two ends of the housing body 721. The housing body 721 is provided with a lubricating oil passage 7211. The upper cover is provided with an oil inlet pipe that connects to one end of the lubricating oil passage 7211, and the lower cover 722 is provided with an oil outlet pipe that connects to the other end of the lubricating oil passage 7211, so that hot oil can flow in the lubricating oil passage 7211 to lubricate the rotation of the spindle 2.

[0056] In this embodiment, the support 71 is arranged obliquely inside the housing 1, so that the coarser particles mentioned above are concentrated at the lower position of the support 71. A coarse particle outlet 15 is provided on the inner wall of the housing 1 near the lower position of the support 71. A coarse particle return mechanism is also provided on the side of the housing 1. The coarse particle return mechanism is connected to the coarse particle outlet 15 to transport the coarse particles to the Laval nozzle 4. Of course, in practice, it can be changed to transport the coarse particles back to the heating furnace for reheating and then spraying impact. The coarse particle return mechanism includes a screw feeder 81, a bucket elevator 82, and a return hopper 83. The screw feeder 81 is connected to the coarse particle outlet 15 on the side wall of the housing 1. The two ends of the bucket elevator 82 are respectively connected to the screw feeder 81 and the return hopper 83. The return hopper 83 is annular and is wrapped around the outer side of the upper end of the housing 1. The bottom of the return hopper 83 is provided with multiple return ports connected to multiple Laval nozzles 4. The return ports are provided with return valves 84. The screw feeder 81 and bucket elevator 82 are existing equipment, and their internal structures will not be described in detail here. The coarser particles are lifted to the return hopper 83 by the screw feeder 81 and bucket elevator 82, and the coarse particles are introduced into the Laval nozzle 4 for re-jetting and crushing, thus achieving triple crushing.

[0057] In this embodiment, if a large number of coarse particles fall to the bottom of the casing 1, the material in the return hopper 83 will be concentrated at the corresponding bucket elevator 82, resulting in uneven distribution of coarse particles returning to each Laval nozzle 4. To solve this problem, this embodiment provides a scraping assembly at the return hopper 83. The scraping assembly includes a support frame 85, multiple scraper blades 86, a guide wheel 87, and a second drive mechanism. The support frame 85 can rotate around the outside of the casing 1, and the multiple scraper blades 86 are installed on the support frame 85 and embedded in the return hopper 83. A guide ring 16 is provided on the outside of the casing 1, and the guide wheel 87 is installed on the support frame 85 and rolls in cooperation with the guide ring 16. The second drive mechanism includes a scraping motor 88 and a transmission gear 89. The scraping motor 88 drives the support frame 85 to rotate through the transmission gear 89. Under the action of the scraper blades 86, the coarse particles in the return hopper 83 are scraped laterally to achieve the effect of uniform material distribution in a circumferential direction.

[0058] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0059] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A flash dryer for comminuting a stream of pulp, characterized in that, The device comprises a slurry storage tank, a heater, an air mill and a dry collector connected in sequence, the slurry storage tank is connected with a slurry inlet pump and a slurry inlet pipe, the slurry inlet pump is connected with the slurry storage tank and the inlet of the heater through the slurry inlet pipe to deliver the slurry material in the slurry storage tank into the heater for heating; The air mill comprises a casing, a main shaft, a rotating target, a plurality of Laval nozzles, a grading screen and a first driving mechanism for driving the main shaft to rotate, the main shaft is longitudinally arranged in the casing and penetrates the rotating target and the grading screen, the grading screen is located above the rotating target, the plurality of Laval nozzles are arranged around the circumferential side of the rotating target, and each Laval nozzle is connected with the outlet of the heater through a steam slurry pipe, so that the moisture in the slurry material is changed into steam after the slurry material is heated, and the material particles are mixed in the steam and accelerated through the nozzles to collide with the rotating target rigidly; the casing is provided with a discharge port above the grading screen, the discharge port is connected with the dry collector through a discharge pipe, and the dry collector is provided with an exhaust mechanism for exhausting air through the discharge pipe.

2. A flash drier according to claim 1, wherein: The heater comprises an upper tube box, an upper tube plate, a heat exchange cylinder, a plurality of heat exchange tubes, a lower tube plate and a lower tube box, the upper tube plate and the lower tube plate are respectively fixed at the two ends of the heat exchange cylinder to form a shell space, the heat exchange cylinder is provided with a heating mechanism for circulating hot air or steam or heat conducting oil in the shell space; the upper tube box is fixed to the upper tube plate and together forms an upper tube space, and the slurry inlet pipe communicates with the upper tube space; the lower tube box is fixed to the lower tube plate and together forms a lower tube space, and the steam slurry pipe communicates with the lower tube space; the plurality of heat exchange tubes are arranged in parallel in the shell space, and the two ends of the plurality of heat exchange tubes are respectively fixed to the upper tube plate and the lower tube plate and respectively connected to the upper tube space and the lower tube space.

3. A flash drier according to claim 1, wherein: The circumferential side of the rotating target is provided with teeth, and the Laval nozzles are arranged in a radial direction relative to the rotating target and are arranged in a direction opposite to the rotating direction of the rotating target.

4. A flash drier according to claim 1, wherein: The grading screen comprises a support block and a plurality of screen strips arranged circumferentially around the support block, and the main shaft penetrates the support block.

5. A flash drier according to claim 4, wherein: The casing is cylindrical, the plurality of Laval nozzles are arranged circumferentially on the side wall of the casing, and the ends of the plurality of screen strips of the grading screen extend to near the inner wall of the casing; the inner wall of the casing is provided with a blocking plate above the grading screen, and the length of the blocking plate is greater than the distance between the screen strips and the inner wall of the casing.

6. A flash drier according to claim 1, wherein: The inner part of the casing is provided with a shaft support assembly for supporting the main shaft, the shaft support assembly comprises a bracket, a bearing seat and a bearing, the bracket is fixed to the casing, the bearing seat is fixed to the bracket, the main shaft penetrates the bearing seat, and the bearing is installed in the bearing seat and clamps the main shaft; the bracket is a partition plate that divides the inner space of the casing into two layers, and the main shaft penetrates below the bracket; the first driving mechanism comprises a main motor, a driving wheel, a driven wheel and a transmission belt, the driving wheel is fixed to the output shaft of the main motor, the driven wheel is fixed to the lower end of the main shaft, and the driving wheel and the driven wheel are connected by the transmission belt.

7. A flash drier according to claim 6, wherein: The bearing seat comprises a seat body, an upper cover and a lower cover, the bearing is clamped in the seat body, the upper cover and the lower cover are respectively fixed at the two ends of the seat body, the seat body is provided with a lubricating oil passage, the upper cover is provided with an oil inlet pipe communicating with one end of the lubricating oil passage, and the lower cover is provided with an oil outlet pipe communicating with the other end of the lubricating oil passage.

8. A flash drier according to claim 6, wherein: The support is arranged obliquely in the casing, and a coarse particle outlet is arranged on the inner wall of the casing close to the lower part of the support; a coarse particle return mechanism is arranged on the side of the casing, and the coarse particle return mechanism is connected with the coarse particle outlet to deliver the coarse particles to the Laval nozzle or the heating furnace.

9. A flash drier according to claim 8, characterised in that: The coarse particle return mechanism comprises a screw feeder, a bucket elevator and a return hopper. The screw feeder is connected with the coarse particle outlet on the side wall of the casing. The two ends of the bucket elevator are connected with the screw feeder and the return hopper respectively. The return hopper is annular. A plurality of return ports are arranged on the bottom of the return hopper and connected with a plurality of Laval nozzles. The return ports are provided with return valves.

10. A flash drier according to claim 9, wherein: The return hopper is provided with a scraping assembly. The scraping assembly comprises a support frame, a plurality of scraper plates, a guide wheel and a second driving mechanism. The support frame is rotatable around the outside of the casing. The plurality of scraper plates are installed on the support frame and embedded in the return hopper. The outside of the casing is provided with a guide convex ring. The guide wheel is installed on the support frame and rolls in cooperation with the guide convex ring. The second driving mechanism comprises a scraping motor and a transmission gear. The scraping motor drives the support frame to rotate through the transmission gear.

Images