阅读说明：本技术 大热容空气流化盘式干燥机 (Large heat capacity air fluidization disc type dryer ) 是由 陈琳 吴玉林 兰万刚 于 2020-09-03 设计创作，主要内容包括：本发明公开了一种大热容空气流化盘式干燥机,解决了现有盘式干燥机存在的换热效率低、能耗高、投资和运行成本高的问题。技术方案包括顶部设有进料口和出气口、底部设有出料口的壳体、壳体中心的转动轴、套装在转动轴上的带有耙叶的耙杆、以及多层上、下交错设置的内向托盘和外向托盘,其特征在于,所述内向托盘和外向托盘内均设有流化腔,所述流化腔顶面覆盖流化体,所述流化腔经热空气管道连通壳体外的热空气进口。本发明结构极为简单、物料换热均匀、换热效率更高、能耗低、设备投资和运行成本低、灵活适应性好。(The invention discloses a large-heat-capacity air fluidization disc type dryer, which solves the problems of low heat exchange efficiency, high energy consumption, and high investment and operation cost of the conventional disc type dryer. The technical scheme includes that the device comprises a shell, a rotating shaft, a rake rod, an inward tray and an outward tray, wherein a feeding hole and an air outlet are formed in the top of the shell, a discharging hole is formed in the bottom of the shell, the rotating shaft is arranged at the center of the shell, the rake rod is sleeved on the rotating shaft and provided with rake blades, and the inward tray and the outward tray are arranged in a multi-layer mode in an up-and-down staggered mode. The invention has the advantages of extremely simple structure, uniform material heat exchange, higher heat exchange efficiency, low energy consumption, low equipment investment and operation cost and good flexibility and adaptability.)

1. The high-heat-capacity air fluidization disc type dryer comprises a shell, a rotating shaft, a rake rod, an inward tray and an outward tray, wherein a feeding hole and an air outlet are formed in the top of the shell, a discharging hole is formed in the bottom of the shell, the rotating shaft is arranged at the center of the shell, the rake rod is sleeved on the rotating shaft and provided with rake blades, and the inward tray and the outward tray are arranged in a multi-layer mode in an up-and-down staggered mode.

2. The large heat capacity air fluidized tray dryer of claim 1, wherein the pressure of the hot air entering the fluidizing chamber is controlled to be 5 to 40 KPa.

3. The large heat capacity air fluidized tray dryer of claim 2, wherein the temperature of the heated air is 100-300 ℃.

4. A high heat capacity air fluidized disc dryer as claimed in any one of claims 1 to 3 wherein the air duct leading into each fluidizing chamber is provided with a regulating valve.

5. A high heat capacity air fluidized tray dryer as claimed in any one of claims 1 to 3, wherein the fluidizing body is a fluidizing cloth, a fluidizing plate or a composite fluidizing plate.

6. The high heat capacity air fluidized tray dryer of claim 5, wherein the pore size of the fluidized body is 20-100 μm.

Technical Field

The invention relates to a dryer, in particular to a large-heat-capacity air fluidization disc type dryer.

Background

Energy problem is one of the main factors restricting economic growth and social sustainable development in China, China must pay attention to the utilization of renewable clean energy due to a plurality of problems existing in conventional energy utilization, and biomass is generally considered to be one of the most promising green renewable energy due to the advantages of rich resources, renewability, low emission of gaseous pollutants in distribution regions and the like.

The water content of biomass materials such as bagasse, straw and the like is up to more than 50%, and the main treatment mode is that the biomass materials are directly combusted as boiler fuel, and the generated steam is used for power generation or industrial production. Bagasse directly burns, and combustion efficiency is low, can lead to the burning unstability, and the heat loss of discharging fume is big, a series of problems such as boiler efficiency is low and CO emission concentration is too high, and is very uneconomic, also not environmental protection, does not accord with energy policy background of energy saving and emission reduction even more. Through the drying to biomass class materials such as bagasse, the moisture content of material can greatly reduced, when the moisture content of biomass class materials such as bagasse reduces to below 40%, boiler efficiency will show and promote, and operating stability will strengthen greatly, effectively improves a series of problems that biomass materials such as bagasse directly burnt.

At present, the biomass materials are dried by a fluidized bed drying technology, a roller drying technology and a disc drying technology, wherein the fluidized bed drying technology and the roller drying technology are used for drying by using waste heat and waste heat of flue gas, continuous drying cannot be realized, the drying effect is limited, the moisture content of the materials can be reduced by 3-4%, and the ideal energy-saving and emission-reducing effects cannot be achieved. The disc drying technology adopts intermediate heat carriers such as steam or heat transfer oil for drying, the drying system is complex, the drying performance cost ratio is low, the drying cost is far higher than the subsequent energy-saving and emission-reduction benefits, and the disc drying technology is not suitable for large-scale industrial production.

Like CN211204777U discloses a disk dryer, including feeding mechanism, drying system and dust pelletizing system, drying system includes casing and desicator, the casing top communicates with feeding mechanism mutually, casing upside inner wall coils and is provided with steam conduit, casing downside inner wall coils and is provided with cooling duct, the desicator includes pivot, drying pan, and scraper blade, the drying pan has a plurality of, and from last to arranging in proper order down inside the casing, the inside lateral wall of casing has a plurality of to link up the piece. The utility model discloses a steam is for the heat supply of drying plate, and the cooperation hot-air is dried wet buggy together, not only can make the buggy dry even, can also improve drying efficiency. In the technical proposal, a heat medium (such as steam or heat conducting oil) is introduced into the inner cavity of the drying tray, the material on the drying tray is indirectly heated and then is led out by a pipeline, the heating mode needs to be provided with special medium heating and circulating pipelines and an air heater, which causes the problems of complex equipment, high investment and operation cost, large energy consumption, uneven material heating and low heat exchange efficiency, even if the hot air heated by the air heater is used for heat exchange, in fact, the main function of the hot air introduction is only to take away moisture, the actual drying efficiency is low, because the pressure of the hot air can not be too high under the condition, if the wind speed is too high, carrier gas can be formed to take away the biomass with light weight and fill the shell, and even the biomass is discharged from the moisture discharging port along the flow direction of the hot air, so that the subsequent biomass separation and collection process is seriously influenced.

Therefore, based on the characteristics of small particle size and light weight of biomass, a drying device with higher heat exchange efficiency, low energy consumption, and low equipment investment and operation cost is needed.

Disclosure of Invention

The invention aims to solve the technical problems and provides the large-heat-capacity air fluidization disc type dryer which is extremely simple in structure, uniform in material heat exchange, higher in heat exchange efficiency, low in energy consumption, low in equipment investment and operation cost, flexible and good in adaptability.

The technical scheme includes that the device comprises a shell, a rotating shaft, a rake rod, an inward tray and an outward tray, wherein a feeding hole and an air outlet are formed in the top of the shell, a discharging hole is formed in the bottom of the shell, the rotating shaft is arranged at the center of the shell, the rake rod is sleeved on the rotating shaft and provided with rake blades, and the inward tray and the outward tray are arranged in a multi-layer mode in an up-and-down staggered mode.

The pressure of the hot air entering the fluidization chamber is controlled to be 5-40 KPa.

The temperature of the hot air is 100-300 ℃.

The gas pipe leading into each fluidization cavity is provided with a regulating valve.

The fluidizing body is a fluidizing cloth, a fluidizing plate or a composite fluidizing plate.

The aperture of the fluidized body is 20-100 μm.

In order to solve the problems existing in the background technology, the inventor considers that the common and easily available hot air in an industrial production system is used as a drying heat source to replace the traditional steam or heat conducting oil, the past indirect heat exchange is changed into the direct heat exchange, and therefore the heat exchange efficiency is greatly improved. Simultaneously, hot air is changed to be directly introduced from the bottom of the shell, introduced into the fluidization cavity at the lower part of the tray through a pipeline and sprayed out through the fluidization body, and the structure has the following advantages: (1) the heat exchange efficiency is high: compare with traditional casing bottom lets in hot-air, the hot-air of this application sends into the fluidization chamber of tray, upwards spouts through the fluidization body again, and the hot-air can not act on the casing space beyond the tray top, but the material on the direct action tray, and the heat loss descends by a wide margin. Under the same drying condition, the air quantity requirement is greatly reduced, the heat exchange efficiency is high, the energy consumption is low, and the investment and operation cost is low; (2) material fluidization state: because the air inlet channel is changed, when hot air is upwards sprayed out from the fluidization cavity through the fluidization body, the materials can form a fluidization state with local vertical jumping on the tray by controlling proper pressure, the materials can be prevented from being separated from the tray and taken away by the hot air, and the drying process that the materials sequentially flow downwards between the inner tray and the outer tray is ensured. (3) Mechanical mixing and fluidization cooperation: on the one hand, the materials are continuously mixed and stirred on the tray by the rotating rake rods and the rake blades, on the other hand, the loosening, suspension, mixing, overturning and disturbance of the materials are realized through the continuous flowing function of the hot air, the materials are effectively mixed and uniformly heated, and the materials are accelerated to be mixed, so that the wet materials and the hot air can be effectively dried by means of countercurrent direct heat exchange.

Furthermore, the pressure of the hot air entering the fluidization cavity can be adjusted and controlled according to the particle size and the quality of the material, so that the material is stably loosened and fluidized on the tray. For biomass materials, the hot air pressure entering the fluidization cavity is preferably controlled to be 5-40KPa, more preferably 5-8KPa, too high fluidization pressure can cause the materials to be separated from the tray, the drying process becomes disordered and uncontrollable, too low fluidization pressure cannot realize the expected stable loose fluidization state, and the drying effect is greatly reduced; all be equipped with the governing valve on the hot-air line who lets in every fluidization chamber and connect to can adjust specific amount of wind according to the material volume on the tray, so that the material on the tray is in best fluidization state, and when the biomass material of dry different masses and particle diameter, also can deal with in a flexible way.

Has the advantages that:

according to the invention, hot air is adopted to replace traditional steam or heat conduction oil, the air fluidization and mechanical mixing principle is combined in the disc type dryer, local fluidization of materials is formed on the inward tray and the outward tray, the drying process of the materials with different humidity is adjustable and controllable, and the device has the outstanding advantages of simple equipment structure, low drying cost, high drying performance cost ratio, wide application range, continuous and stable operation, high reliability, high heat utilization rate, good drying effect, adjustable and controllable drying process and the like, solves the problems of applicability of material drying and cost performance of material drying energy consumption and income under different application scenes, and is particularly suitable for drying biomass materials.

Drawings

FIG. 1 is a schematic view of the structure of the present invention.

Fig. 2 is a partial schematic view of a fluidization chamber and a fluidizing body.

Wherein, 1-shell, 2-hot air inlet, 3-rotating shaft, 4-speed regulating driving device, 5-outward tray, 6-inward tray, 7-harrow bar, 8-harrow leaf, 9-feeding inlet, 10-material, 11-central material hole, 12-discharging outlet, 13-hot air main pipe, 14-hot air branch pipe, 15-regulating valve, 16-fluidizing chamber, 17-fluidizing body and 18-air outlet.

Detailed Description

The invention is further explained below with reference to the drawings in which:

referring to fig. 1, the invention comprises a shell 1 with a feed inlet 9 and an air outlet 18 on the top and a discharge outlet 12 on the bottom, a rotating shaft 3 in the center of the shell 1, a harrow bar 7 with harrow blades 8 sleeved on the rotating shaft 3, and multiple layers of inward trays 6 and outward trays 5 which are staggered up and down. The inside tray 6 and the outside tray 5 are both provided with a fluidization cavity 16, the top surface of the fluidization cavity 16 is covered with a fluidization body 17, and the fluidization cavity 16 is communicated with a hot air inlet 2 outside the shell 1 through a hot air pipeline. The hot air pipeline consists of a hot air main pipe 13 positioned outside the shell 1 and hot air branch pipes 14 penetrating through the shell and connected with various fluidization cavities 16, and the hot air branch pipes 14 are provided with regulating valves 15. The fluidized body is fluidized cloth, a fluidized plate or a composite fluidized plate, and the aperture of the fluidized body is 20-100 mu m.

The outward tray 5 and the inward tray 6 are arranged at intervals along the length direction of the rotating shaft 3, and after materials enter the outward tray 5 on the first layer, the materials are slowly pushed to the edge of the outward tray 5 and finally fall onto the inward tray 6 on the next layer by means of the driving of the rake rod 7 and the rake blade 8 while being mixed and dried. The materials are continuously mixed and dried on the inward tray 6, the materials are pushed to the central material hole 11 of the inward tray 6 under the drive of the rake rod 7 and the rake blade 8, and the materials continuously move and fall on the next outward tray 5. According to different material types, different tray layer numbers and air fluidization speeds are set, the materials are subjected to the above movement process, the flowing direction control of the materials is realized through continuous circulation reciprocation, the materials are ensured to have enough residence time inside the shell, the drying time of the materials is ensured, and the materials finally flow out of the dryer from the discharge hole 12 of the tray at the lowest layer.

The process comprises the following steps:

the process of the dryer of the present invention will be described in detail below by taking the drying of bagasse as an example. The water content of the bagasse is 50 percent (mass percentage), and the diameter range is 5-20 mm.

Wet materials (bagasse) enter from a feed inlet 9 and directly fall onto the first layer of outward trays 5 by the aid of self gravity, on one hand, the rotating shaft 3 is driven by the driving device to rotate, meanwhile, the rake blades 8 of the rake rods 7 are driven to rotate anticlockwise, relative motion between the rake blades 8 of the rake rods 7 and each tray is realized, under the continuous mixing and stirring of the rake blades 8, the materials in the outward trays 5 fall into the downward inward trays 6 from the periphery, and under the stirring of the rake blades 8, the materials in the inward trays 6 fall onto the downward outward trays 5 from the central material holes 11, and the whole drying process of the materials is a process of continuously advancing (falling) in a reciprocating motion curve between the outward trays 5 and the inward trays 6; on the other hand, 100-300 ℃ hot air is introduced from a hot air main pipe 13, the flow is regulated by a regulating valve 15 on a hot air branch pipe 14, and then the hot air enters a fluidizing chamber 16 at the lower part of each tray (the fluidizing air pressure is controlled to be 5-8KPa in the embodiment), finally the hot air is sprayed upwards through a fluidizing body 17 and directly contacts with the materials on the trays, and the loosening, suspension, mixing, overturning and disturbance of the materials on the local trays can be realized by controlling the fluidizing speed of the air, so that the mixing and drying process of the materials is accelerated. Because the fluidization state only occurs on the tray, the local gas flow rate is controllable, and the shell gap outside the tray is not filled with gas flow, the material can be ensured not to be brought to other positions outside the tray by the gas, the material can be ensured to advance according to a preset route, and finally, the separation and collection of the dried material can be effectively realized.

Wet materials and hot air are subjected to direct countercurrent heat exchange, the expected drying effect is achieved through the movement process of the multiple layers of trays, and the dried materials flow out of the dryer from the discharge port 12 of the tray on the lowest layer and enter the subsequent storage and use process.

The hot air after the heat exchange by the countercurrent direct contact with the materials is changed into exhaust air, the exhaust air moves in the shell 1 like slow turbulence, rises along the inner wall of the shell 1 and is finally gathered to an exhaust port at the top of the shell, the exhaust air is treated by a dedusting filter device to ensure that the dust concentration is less than or equal to 10mg/Nm3, and then the exhaust air is directly discharged into the air.

Comparative example 1, a traditional disc dryer is adopted, and hot steam is introduced as a heat medium to indirectly exchange heat with materials;

comparative example 2, in addition to the conventional tray dryer structure of comparative example 1, a hot air inlet is provided at the bottom of the dryer, and hot air at 300 ℃ of 100 ℃ is introduced to carry away the exhaust gas in the shell.

In the invention, on the premise of the same shell size, the number and the size of the inward and outward trays 6 and 5 as those of comparative examples 1 and 2, the same wet material bagasse (initial water content of 50 mass%) is dried, and the experimental results are compared as follows under the condition that the drying time is 30 min:

the water content of the material in the comparative example 1 is reduced from 50% to 45%, the uniform drying amount of the material is not more than 60%, and the problems of high energy consumption, complex system, high investment cost and high operation cost exist due to the adoption of steam indirect heat exchange (the market price of steam in industrial production is 260 yuan/ton).

The water content of the material in the comparative example 2 is reduced from 50% to 45%, the uniform drying amount of the material is not more than 60%, and the energy consumption, the investment cost and the operation cost are all higher than those in the comparative example 1 by adopting a drying mode of heating air through indirect steam heat exchange.

The water content of the embodiment of the invention is reduced to below 40% from 50%, the drying efficiency is higher, the materials with the water content of above 95% are uniformly dried, and hot air in matched industrial production is adopted, so that additional purchase of steam is not needed, compared with a comparative example 1, the equipment investment cost can be reduced by more than 30%, the drying energy consumption is reduced by more than 25%, and the technical effect is obvious.