Fly ash dryer and drying apparatus

Abstract

The present application relates to fly ash drying technical field, disclose a kind of fly ash dryer and drying equipment, fly ash dryer includes shell (3) and the feed device (2) capable of being connected to the inside chamber of the shell (3), the inside chamber includes mixing chamber (302) and along vertical direction is connected to the drying chamber (303) top of the mixing chamber (302), the bottom of the mixing chamber (302) is equipped with the inlet for hot gas to enter, the upper portion of the drying chamber (303) is equipped with outlet, the feed device (2) includes the feeding machine (202) being arranged on the shell (3), the feeding port of the feeding machine (202) is located at the outside of the shell, the feeding port of the feeding machine (202) is located in the mixing chamber (302) and is towards the air inlet. By the above technical scheme, wet fly ash enters drying chamber along with hot gas, and collision occurs with the inner wall of drying chamber, fly ash exchanges with wall heat mass, so that fly ash is dried more fully.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fly ash drying, in particular to a fly ash dryer and drying equipment. BACKGROUND

[0002] Fly ash is the main solid waste discharged by coal-fired power plants, which has certain harmfulness to the environment. However, fly ash can be well applied in construction and road engineering projects due to its certain volcanic ash characteristics and self-hardening property.

[0003] At present, some thermal power plants use water spraying to remove dust, which results in that the discharged fly ash has a large moisture content, low activity, uneven fineness and is difficult to be efficiently utilized. Fly ash utilization projects basically require dry ash. Traditional fly ash drying equipment generally has a large floor area, high energy consumption, is not easy to operate, and is prone to agglomeration and clumping during the drying process, which affects the overall activity of fly ash. SUMMARY

[0004] The present application aims to overcome the problem of incomplete drying in the prior art and provide a fly ash dryer and drying equipment, which can blow wet fly ash in reverse to achieve complete drying.

[0005] In order to achieve the above-mentioned purpose, the present application provides a fly ash dryer, which comprises a shell and a feeding device capable of communicating with the internal chamber of the shell, the internal chamber comprises a mixing chamber and a drying chamber communicated with the top of the mixing chamber in the vertical direction, the bottom of the mixing chamber is provided with an inlet for hot gas to enter, and the upper part of the drying chamber is provided with an outlet, the feeding device comprises a feeding machine arranged on the shell, the feeding port of the feeding machine is located outside the shell, and the feeding port of the feeding machine is located in the mixing chamber and faces the air inlet.

[0006] Optionally, it further comprises an air flow distribution plate arranged between the mixing chamber and the air inlet, the air flow distribution plate is provided with a plurality of air holes distributed around the central axis, and the outlet of the air hole is inclined by 45 degrees to 60 degrees in the circumferential direction.

[0007] Optionally, the flow area of the mixing chamber decreases first and then increases in the vertical upward direction.

[0008] Optionally, a plurality of baffles are arranged in the drying chamber and spaced apart in the vertical direction.

[0009] Optionally, it further comprises a material collecting hopper communicated with the outlet, and the outlet is located on the side wall of the upper part of the drying chamber.

[0010] Optionally, a guide plate is arranged at the turning part of the top of the drying chamber, and the guide plate is inclined towards the outlet.

[0011] Optionally, the aggregate hopper comprises a separation chamber in communication with the drying chamber and an aggregate chamber at the bottom of the separation chamber, the top of the separation chamber is provided with a gas outlet, and a dust collector is arranged on the gas outlet.

[0012] Optionally, a purge nozzle is arranged on the shell and faces the edge of the outlet.

[0013] The second aspect of the present application provides a drying device comprising the fly ash dryer of any one of the above technical contents and an air inlet device connected to the air inlet, the air inlet device comprises a pressure element in communication with the atmosphere and a heater connected between the pressure element and the air inlet, and the drying chamber is provided with a gas supplement pipeline connected to the heater.

[0014] Optionally, the outlet is communicated with an aggregate hopper provided with a gas outlet at the top, and the drying device further comprises a heat exchanger, the inlet of the heat exchanger is connected to the gas outlet and the atmosphere, and the outlet of the heat exchanger is connected to the pressure element.

[0015] Through the above technical solution, the wet fly ash enters the mixing chamber through the feeding device, the wet fly ash falls under the action of gravity, the hot gas is blown from the bottom of the mixing chamber from bottom to top, the wet fly ash receives the upward force of the hot gas which is greater than the gravity, and the wet fly ash enters the drying chamber together with the hot gas and collides with the inner wall of the drying chamber, the fly ash exchanges heat with the wall, and the dried fly ash is discharged from the outlet, the collision between the falling wet fly ash particles and the rising particles is intensified in the mixing chamber, the fly ash particle agglomeration phenomenon is effectively avoided, and the fly ash can be fully dried in the drying chamber. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of an embodiment of the drying device in the present application;

[0017] Figure 2 is a structural schematic diagram of an embodiment of the air flow distribution plate in the present application.

[0018] MARKING OF THE DRAWINGS

[0019] 1, air inlet device, 2, feeding device, 3, shell, 4, aggregate hopper, 5, dust collector, 6, heat exchanger, 101, pressure element, 102, first temperature sensor, 103, heater, 104, first pressure sensor, 105, second pressure sensor, 106, third pressure sensor, 201, pulse valve, 202, feeder, 301, air flow distribution plate, 302, mixing chamber, 303, drying chamber, 304, baffle, 305, deflector, 306, purge nozzle, 307, second temperature sensor, 401, separation chamber, 402, aggregate chamber. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] The present invention provides a fly ash dryer, including a shell 3 and a feeding device 2 that can communicate with the internal chamber of the shell 3. The internal chamber includes a mixing chamber 302 and a drying chamber 303 that is vertically connected to the top of the mixing chamber 302. The bottom of the mixing chamber 302 is provided with an inlet for hot gas to enter, and the upper part of the drying chamber 303 is provided with an outlet. The feeding device 2 includes a feeder 202 installed on the shell 3. The feed inlet of the feeder 202 is located outside the shell 3, and the feed outlet of the feeder 202 is located inside the mixing chamber 302 and faces the air inlet.

[0022] like Figure 1 As shown, fly ash enters the mixing chamber 302 through the feeder 202 and falls down. The feeder 202 is composed of 5 to 12 parabolic swirling blades with a helical angle of 45° to 60°, and a pulse valve 201 is provided on the feeder 202. The pulse valve 201 can perform periodic operation to prevent the feeder 202 from being blocked. Hot gas is blown upward from the bottom of the mixing chamber 302. The hot gas can disperse the wet fly ash and blow the fly ash into the drying chamber 303. The hot gas can drive the fly ash to flow upward until it is completely dry.

[0023] Through the above technical solution, wet fly ash enters the mixing chamber 302 through the feeding device 2. The wet fly ash falls under the action of gravity. Hot gas is blown in from the bottom of the mixing chamber 302 from bottom to top. The upward force of the hot gas on the wet fly ash is greater than the gravity, and it enters the drying chamber 303 with the hot gas. After the hot gas is introduced into the drying chamber 303, the temperature of the shell 3 rises accordingly, and the fly ash can collide with the inner wall of the drying chamber 303. The fly ash and the wall of the shell 3 undergo heat and mass exchange. The dried fly ash is discharged from the outlet. In the mixing chamber 302, the collision between the falling wet fly ash particles and the rising particles is enhanced, which effectively avoids the phenomenon of fly ash particles clumping. In the drying chamber 303, the fly ash can be fully dried.

[0024] Furthermore, the fly ash dryer also includes an airflow distribution plate 301 disposed between the mixing chamber 302 and the air inlet. The airflow distribution plate 301 is provided with multiple layers of air holes distributed around the central axis, and the outlet orientation of the air holes is tilted 45 degrees to 60 degrees in the circumferential direction.

[0025] Combination Figure 1 and Figure 2As shown, an airflow distribution plate 301 is provided on the cross-section of the bottom of the mixing chamber 302. The airflow distribution plate 301 has multiple layers (or multiple rings) of air holes spaced radially (only one layer is shown in the figure). The outlet direction of the air holes is deflected 45 to 60 degrees in the circumferential direction (the outlet direction forms an angle of 45 to 60 degrees with the vertical direction). This allows the gas blown out of the air holes to move in the circumferential direction while rising. After the hot air passes through the airflow distribution plate 301, it forms a swirling flow in the mixing chamber, which can drive the fly ash to rise in a spiral shape and make the fly ash continuously collide with the inner wall of the shell 3 to carry out heat and mass exchange, thereby increasing the drying efficiency of the fly ash. The more layers of air holes on the airflow distribution plate 301 and the more air holes in each layer, the stronger the spiral airflow generated.

[0026] As an alternative implementation, the flow area of ​​the mixing chamber 302 first decreases and then increases in the vertically upward direction.

[0027] like Figure 1 As shown, during the upward movement of hot air in the mixing chamber 302, due to the decrease in the flow area of ​​the mixing chamber 302, the hot air converts some of its thermal energy into kinetic energy. Then, the flow area of ​​the mixing chamber 302 increases (after expanding the inner diameter), releasing more static pressure. This working principle is similar to that of the Laval nozzle. By changing the size of the inner diameter of the mixing chamber 302 (the size of the flow area), a small amount of static pressure enhancement can be obtained, which strengthens the collision between the descending wet fly ash particles and the rising particles, effectively avoids the agglomeration of fly ash particles, and reduces the residence time. The shrinkage ratio of the intermediate contraction of the mixing chamber 302 is 0.6 to 0.8.

[0028] Furthermore, the drying chamber 303 is provided with multiple baffles 304 arranged at intervals along the vertical direction.

[0029] like Figure 1 As shown, when hot air enters the drying chamber 303, it collides with the baffle 304 and is forced to flow towards the high-temperature wall of the shell 3, which enhances the heat and mass exchange between the fly ash particles and the wall and improves the drying efficiency; the distance between adjacent baffles is 0.5 to 1.5 meters.

[0030] The fly ash dryer also includes a collection hopper 4 connected to the outlet, which is located on the side wall of the upper part of the drying chamber 303.

[0031] like Figure 1 As shown, the collection hopper 4 is set on the side of the shell 3, so that hot air flows into the drying chamber 303 and enters the collection hopper 4 in a horizontal direction. The hot air drives the fly ash to change from vertical to horizontal movement. After the fly ash rises to the top of the drying chamber 303, it collides with the top wall, which further enhances the heat and mass exchange between the particles and the wall surface and improves the drying efficiency.

[0032] In some embodiments, a guide plate 305 is provided at the top bend of the drying chamber 303, and the guide plate 305 is inclined toward the outlet.

[0033] like Figure 1 As shown, the drying chamber 303 has a top plate and side plates. Fly ash and airflow flow upward along the side plates to the top plate, and then collide with the top plate and flow along the top plate toward the outlet. The guide plate 305 is set at the corner of the top plate and the side plates to guide the rising airflow to turn and begin to flow horizontally toward the outlet.

[0034] like Figure 1 As shown, the guide plate 305 is an arc-shaped plate. The inlet tangential angle of the guide plate 305 is parallel to the vertical direction, and the outlet tangential angle is parallel to the horizontal direction. This allows the fly ash to rise to the top and collide with the guide plate 305. Under the guidance of the guide plate 305, the fly ash smoothly transitions from vertical to horizontal movement, allowing the fly ash to enter the collection hopper 4 smoothly. This effectively prevents the fly ash from accumulating at the top of the drying chamber 303.

[0035] The hopper 4 includes a separation chamber 401 connected to the drying chamber 303 and a collection chamber 402 located at the bottom of the separation chamber 401. The top of the separation chamber 401 is provided with a gas outlet, and a dust collector 5 is provided on the gas outlet.

[0036] like Figure 1 As shown, after the fly ash and hot air enter the collection hopper 4, they collide with the side wall of the separation chamber 401. A portion of the fly ash falls into the collection chamber 402 under the action of gravity, while the remaining fly ash flows to the gas outlet under the action of hot air. The hot air is discharged from the gas outlet, while the fly ash is blocked in the separation chamber 401 by the action of the dust collector 5, and then falls into the collection chamber 402 for collection under its own gravity.

[0037] In one embodiment, the housing 3 is provided with a purge nozzle 306, which faces the edge of the outlet.

[0038] like Figure 1 As shown, a purge nozzle 306 is provided at the outlet of the shell 3. The purge nozzle 306 can purge periodically to prevent fly ash from clogging the outlet.

[0039] Another aspect of the present invention provides a drying device, including a fly ash dryer according to any one of the above technical contents and an air inlet device 1 connected to the air inlet. The air inlet device 1 includes a pressure member 101 connected to the atmosphere and a heater 103 connected between the pressure member 101 and the air inlet. The drying chamber 303 is provided with a supplementary air pipeline connected to the heater 103.

[0040] like Figure 1As shown, air enters the heater 103 through the pressure element 101 for heating, and the heated hot air enters the mixing chamber 302 in part to form the main drying gas flow of the fly ash dryer, and the other part of the heated hot air directly enters the drying chamber 303.

[0041] The pressure element 101 is a variable frequency blower, and a first pressure sensor 104 is installed at the outlet of the blower to detect the outlet dryer pressure, and when the drying gas pressure is lower than the set value, a signal is sent to the main control device, and the main control device increases the blower speed after receiving the signal to increase the outlet drying gas pressure, and the sensor feeds back data to the main control device, and the blower operating parameters are adjusted according to the pressure data to avoid fly ash particles from being deposited or not completely dried and being carried into the finished product collecting device;

[0042] A first temperature sensor 102 is installed at the outlet of the heater 103 to detect the temperature of the hot air at the outlet of the heater 103, and when the hot air temperature is lower than or higher than the set value, a signal is sent to the main control device, and the main control device performs PID operation after receiving the signal to increase or decrease the power of the heater 103 to stabilize the hot air temperature within the design range, and the main control device is fed back data by the sensor to accurately adjust the power of the heating device and effectively avoid waste of heat energy;

[0043] A second pressure sensor 105 and an adjusting valve are arranged between the heater 103 and the mixing chamber 302, and a third pressure sensor 106 is arranged on the air supplementing pipeline, and when the pressure is lower than the set value, a signal is sent to the main control device, and the main control device increases the blower speed or increases the opening of the adjusting valve to increase the drying gas pressure after receiving the signal;

[0044] A second temperature sensor 307 is installed on the drying chamber 303 to detect the temperature in the drying chamber 303, and the inner wall temperature of the drying chamber 303 is controlled at 110-250°C according to requirements.

[0045] Further, the outlet is communicated with a material collecting hopper 4 provided with a gas outlet at the top, and the drying device further comprises a heat exchanger 6, the inlet of the heat exchanger 6 is connected with the gas outlet and the atmosphere, and the outlet of the heat exchanger 6 is connected with the pressure element 101.

[0046] As shown in the figure, Figure 1 The dried tail gas enters the heat exchanger 6 to mix with air to preheat fresh air, and after mixing, the air enters the heater 103 for heating, which can effectively improve the energy utilization efficiency.

[0047] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications and combinations should also be considered as disclosed by the present application, and all belong to the protection scope of the present application.

[0048] It should also be noted that any technically feasible combination of the various technical features described in the above embodiments is possible, provided that there is no contradiction. In order to avoid unnecessary repetition, the present application will not describe the various possible combinations again.

[0049] Furthermore, any combination of the various different embodiments of the present application is possible, provided that it does not contradict the idea of the present application, and should likewise be considered as being disclosed by the present application.

Claims

1. A fly ash dryer characterized by, The device comprises a shell (3) and a feeding device (2) capable of communicating with the internal chamber of the shell (3), the internal chamber comprises a mixing chamber (302) and a drying chamber (303) communicating with the top of the mixing chamber (302) in the vertical direction, the bottom of the mixing chamber (302) is provided with an air inlet for hot gas, the upper part of the drying chamber (303) is provided with an outlet, the feeding device (2) comprises a feeder (202) arranged on the shell (3), the feeding port of the feeder (202) is located outside the shell (3), and the feeding port of the feeder (202) is located in the mixing chamber (302) and faces the air inlet. A plurality of baffles (304) are arranged in the drying chamber (303) and spaced apart in the vertical direction, the baffles (304) are spaced apart from the inner wall of the drying chamber (303), and the flow area of the mixing chamber (302) decreases first and then increases in the vertical upward direction.

2. The fly ash dryer of claim 1, wherein, The device further comprises an air flow distribution plate (301) arranged between the mixing chamber (302) and the air inlet, the air flow distribution plate (301) is provided with a plurality of air holes distributed around the central axis, and the outlet of the air hole is inclined by 45-60 degrees in the circumferential direction.

3. The fly ash dryer of claim 1, wherein, The device further comprises a collecting hopper (4) connected with the outlet, and the outlet is located on the side wall of the upper part of the drying chamber (303).

4. The fly ash dryer of claim 3, wherein, The drying chamber (303) is provided with a guide plate (305) at the turning part of the top, and the guide plate (305) is inclined towards the outlet.

5. The fly ash dryer of claim 3, wherein, The collecting hopper (4) comprises a separation chamber (401) connected with the drying chamber (303) and a collecting chamber (402) located at the bottom of the separation chamber (401), and the top of the separation chamber (401) is provided with a gas outlet, and the gas outlet is provided with a dust collector (5).

6. The fly ash dryer of claim 3, wherein, The shell (3) is provided with a blowing nozzle (306) facing the edge of the outlet.

7. A drying apparatus, characterized by The device comprises the fly ash dryer of any one of claims 1-6 and an air inlet device (1) connected to the air inlet, the air inlet device (1) comprises a pressure element (101) connected with the atmosphere and a heater (103) connected between the pressure element (101) and the air inlet, and the drying chamber (303) is provided with a gas supplement pipeline connected with the heater (103).

8. The drying apparatus according to claim 7, characterized in that The outlet is connected with a collecting hopper (4) provided with a gas outlet at the top, and the drying device further comprises a heat exchanger (6), the inlet of the heat exchanger (6) is connected with the gas outlet and the atmosphere, and the outlet of the heat exchanger (6) is connected with the pressure element (101).

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