1. A drying method of granulating materials and small-particle materials is characterized in that: the materials are dried in a fractional section from top to bottom, the bottommost section is a cooling section, the rest sections are drying sections, the sections are communicated from top to bottom, cold air enters the cooling section and exchanges heat with the materials to be changed into hot air, and the hot air is introduced into the drying section at the topmost section to dry the materials and then is discharged outside; the hot air enters from the drying section above the cooling section, the material is dried and then is dried by introducing the previous drying section, and so on until the hot air is introduced into the secondary top section drying section to dry the material and then is discharged.

2. Apparatus for drying a granulated material, a small granular material, as defined in claim 1, wherein: the drying device comprises a hopper, a drying cavity and a conveying belt, wherein a bottom outlet of the hopper is connected with a top inlet of the drying cavity, and a bottom outlet of the drying cavity corresponds to the conveying belt;

the drying cavity is sequentially divided into a 1 st section, a 2 nd section, … … and an Nth section from top to bottom, N is a natural number more than 3, and two outer sides of each section are respectively and symmetrically communicated with two gas distribution chambers;

the pipeline of the gas distribution chamber corresponding to one side of the Nth section is connected with a cold air supply source, the pipeline of the gas distribution chamber corresponding to the other side of the Nth section is connected with the gas distribution chamber corresponding to one side of the 1 st section, and the gas distribution chamber corresponding to the other side of the 1 st section is connected with an external bag-type dust collector through a pipeline;

the gas distribution chamber corresponding to one side of the section N-1 is connected with a hot air supply source through a pipeline, the gas distribution chamber corresponding to the other side of the section N-1 is connected with the gas distribution chamber corresponding to one side of the section N-2 through a pipeline, the gas distribution chamber corresponding to the other side of the section N-2 is connected with the gas distribution chamber corresponding to one side of the section N-3 through a pipeline, and so on until the gas distribution chamber corresponding to one side of the section 2 is connected with an external bag-type dust collector through a pipeline.

3. A drying device for granulated material, small granular material according to claim 2, characterized in that: the drying device is in a vertical flat shape.

4. A drying device for granulated material, small granular material according to claim 2, characterized in that: the 1 st section to the N-1 st section are respectively provided with a plurality of conical hoppers at the lower parts thereof.

5. A drying device for granulated material, small granular material according to claim 2, characterized in that: and the pipeline below the gas distribution chamber is connected with a powder discharge valve.

6. A drying device for granulated material, small granular material according to claim 2, characterized in that: the gas distribution chamber is separated from the drying cavity through a distribution chamber perforated plate, a plurality of taper holes are formed in the distribution chamber perforated plate, small holes of the taper holes face the drying cavity, large holes of the taper holes face the gas distribution chamber, and the diameter of the small holes is smaller than that of the material.

Background

The disc granulation is widely applied to the fields of mineral processing, fertilizer processing and medicine processing, and the powder is sprayed with water in a disc granulator to rotate to form spherical particles, and the product is obtained after drying. Before drying the cake material, it is usually crushed and then dried, such as drying bentonite.

In the drying link, the granulated material and the small-particle material have certain fluidity, and the materials are dried by adopting rotary kiln drying equipment and fluidized bed drying equipment, wherein the rotary kiln is widely applied and accounts for more than 80 percent of the drying equipment.

The rotary kiln is huge in volume, and the direct length is usually 1.6-2.5 meters, and the length is 18-30 meters. A guide plate is arranged in the rotary kiln, and materials are continuously rolled in the rotary kiln and contacted with hot air to obtain heat exchange. Because the sectional area of the rotary kiln is large, though the rotary kiln is continuously rolled, the chance of contacting materials with hot air is limited, and the heat exchange is insufficient. When the bentonite cat litter is dried in a rotary kiln with the diameter of 1.8 meters and the length of 18 meters, if the required moisture is less than or equal to 5 percent, the temperature of a smoke outlet of the rotary kiln reaches 115 ℃, and if cold air is not sucked into a discharge end, the outlet temperature is higher; the materials are continuously rolled in the rotary kiln, and the particle materials are easy to break and generate dust; the temperature of the product discharged from the rotary kiln is too high, and the heat cannot be recycled; the rotary kiln has too large volume and large heat loss.

The fluidized bed drying equipment is characterized in that materials are blown up by hot air in a fluidized bed, the materials are in a suspension state, the dried materials become light, and then the materials are discharged from a discharge hole which is arranged at a certain distance away from a pattern plate. Fluidized bed drying equipment has made progress in heat exchange than rotary kiln drying equipment, but because crushing equipment, granulation equipment are difficult to accomplish the particle size of material unanimity, the phenomenon that the material that the particle size is less exists and just is discharged in time of drying. Meanwhile, the materials move up and down in the equipment to cause mutual friction among the materials to generate dust, so that the product quality is difficult to avoid being influenced. And meanwhile, cooling equipment cannot be arranged in the fluidized bed, and the heat of the product cannot be recycled.

Whether rotary kiln drying or fluidized bed drying is adopted, if the product of the granular material with strict dust requirements is produced, additional dust removing equipment for the product is required before packaging.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a drying method and a drying device for granulating materials and small-particle materials, which adopt sectional drying to improve the contact and collision probability of cold air and hot air and the dried materials, thereby improving the heat exchange efficiency, recovering the waste heat after drying and realizing the drying of the materials under a relative static state; the drying process can avoid the breakage of materials caused by falling from high altitude, ensure that the product is not deformed and has no dust, and ensure the product quality; meanwhile, the heat loss is reduced, the heat is fully utilized, the maintenance rate is low, and the method is suitable for large-scale continuous production. The technical scheme adopted by the invention is as follows:

a drying method for granulated materials and small-particle materials is characterized in that the materials are dried in a fractional section from top to bottom, the bottommost section is a cooling section, the rest sections are drying sections, the sections are communicated from top to bottom, cold air enters the cooling section and exchanges heat with the materials to be changed into hot air, and the hot air is introduced into the drying section at the topmost section to dry the materials and then is discharged; the hot air enters from the drying section above the cooling section, the material is dried and then is dried by introducing the previous drying section, and so on until the hot air is introduced into the secondary top section drying section to dry the material and then is discharged.

A drying device for granulated materials and small-particle materials comprises a hopper, a drying cavity and a conveying belt, wherein a bottom outlet of the hopper is connected with a top inlet of the drying cavity, and a bottom outlet of the drying cavity corresponds to the conveying belt;

the drying cavity is sequentially divided into a 1 st section, a 2 nd section, … … and an Nth section from top to bottom, N is a natural number more than 3, and two outer sides of each section are respectively and symmetrically communicated with two gas distribution chambers;

the pipeline of the gas distribution chamber corresponding to one side of the Nth section is connected with a cold air supply source, the pipeline of the gas distribution chamber corresponding to the other side of the Nth section is connected with the gas distribution chamber corresponding to one side of the 1 st section, and the gas distribution chamber corresponding to the other side of the 1 st section is connected with an external bag-type dust collector through a pipeline;

the gas distribution chamber corresponding to one side of the section N-1 is connected with a hot air supply source through a pipeline, the gas distribution chamber corresponding to the other side of the section N-1 is connected with the gas distribution chamber corresponding to one side of the section N-2 through a pipeline, the gas distribution chamber corresponding to the other side of the section N-2 is connected with the gas distribution chamber corresponding to one side of the section N-3 through a pipeline, and so on until the gas distribution chamber corresponding to one side of the section 2 is connected with an external bag-type dust collector through a pipeline.

The drying device is in a vertical flat shape.

The 1 st section to the N-1 st section are respectively provided with a plurality of conical hoppers at the lower parts thereof.

And the pipeline below the gas distribution chamber is connected with a powder discharge valve.

The gas distribution chamber is separated from the drying cavity through a distribution chamber perforated plate, a plurality of taper holes are formed in the distribution chamber perforated plate, small holes of the taper holes face the drying cavity, large holes of the taper holes face the gas distribution chamber, and the diameter of the small holes is smaller than that of the material.

Compared with the prior art, the invention has the following beneficial effects:

1. the material drying fraction is dry, so that the contact and collision probability of cold air and hot air and the dried material is improved, and the heat exchange efficiency is improved. The water content of the material can reach less than or equal to 3 percent under the condition that the outlet temperature is 70 ℃, thereby achieving the purpose of saving energy consumption.

2. The hardness of the material is continuously improved along with the continuous evaporation of the moisture in the drying process of the material, and the material cannot be pressed and deformed in the drying process; meanwhile, the moving speed between the materials is slow, and little dust is generated due to the friction between the materials; it is not like the rotary kiln that the continuous tumbling causes the particle breaking.

3. The device provided by the invention realizes the dust removal process of the product in the drying process of the product, dust in the product is brought out by hot air in the drying process, no additional dust removal equipment is needed before the product is packaged, and the product reaches a dust-free grade.

4. The last section of the device is a cooling section, heat energy is used for drying in the drying section 1, the heat energy is fully utilized, and the drying energy consumption is low.

5. Each drying section of the device is not provided with a transmission device, so that the maintenance rate is reduced; meanwhile, the power consumption is reduced.

6. The device has small floor area and low manufacturing cost, and compared with a rotary kiln and a fluidized bed, the cost is reduced by more than 60%.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a view in the direction A of FIG. 1;

fig. 3 is a schematic sectional view B-B of fig. 1.

In the figure: 1-a hopper, 2-a first section drying outlet gas distribution chamber, 3-a drying cavity, 4-a heat exchange air drying outlet pipe, 5-a first section drying inlet gas distribution chamber, 6-a powder discharge valve, 7-a heat exchange hot blast pipe, 8-a second section drying inlet gas distribution chamber, 9-a second section drying outlet gas distribution chamber, 10-a first hot blast ring pipe, 11-a drying flue gas outlet pipe, 12-a third section drying inlet gas distribution chamber, 13-a third section drying outlet gas distribution chamber, 14-a second hot blast ring pipe, 15-a fourth section drying inlet gas distribution chamber, 16-a hot blast inlet pipe, 17-a fourth section drying outlet gas distribution chamber, 18-a cold air inlet gas distribution chamber, 19-a hot air outlet gas distribution chamber, 20-cold air inlet pipe, 21-conveying belt, 22-gas distribution chamber perforated plate and 23-conical hopper.

Detailed Description

The technical solutions of the present invention are described in detail below with reference to the accompanying drawings and the specific embodiments, but the present invention is not limited to the claims.

As shown in fig. 1, 2 and 3, the drying device for granulated materials and small granular materials is a vertical flat device; the top is hopper 1, and the export of hopper 1 bottom is connected the top entry of drying chamber 3, and the bottom export of drying chamber 3 corresponds conveyer belt 21.

The drying cavity 3 is divided into a 1 st drying section, a 2 nd drying section, a 3 rd drying section, a 4 th drying section and a cooling section from top to bottom; the two outer sides of the upper part of the first drying section 1 are respectively and symmetrically communicated with a first section drying outlet gas distribution chamber 2 and a first section drying inlet gas distribution chamber 5; the two outer sides of the upper part of the second drying section 2 are respectively and symmetrically communicated with a second section drying inlet gas distribution chamber 8 and a second section drying outlet gas distribution chamber 9; the two outer sides of the upper part of the third drying section 3 are respectively and symmetrically communicated with a third section drying outlet gas distribution chamber 13 and a third section drying inlet gas distribution chamber 12; the two outer sides of the upper part of the 4 th drying section are respectively and symmetrically communicated with a fourth section drying inlet gas distribution chamber 15 and a fourth section drying outlet gas distribution chamber 17; the two outer sides of the upper part of the cooling section are respectively and symmetrically communicated with a cold air inlet gas distribution chamber 18 and a hot air outlet gas distribution chamber 19.

The first-section drying outlet gas distribution chamber 2 is connected with an external bag-type dust collector through a heat exchange air drying outlet pipe 4, the bag-type dust collector is connected with a draught fan, and the first-section drying inlet gas distribution chamber 5 is communicated with a hot air outlet gas distribution chamber 19 through a heat exchange hot air pipe 7; the second section of drying inlet gas distribution chamber 8 is communicated with a third section of drying outlet gas distribution chamber 13 through a first hot air ring pipe 10, the second section of drying outlet gas distribution chamber 9 is connected with a drying flue gas outlet pipe 11, the drying flue gas outlet pipe 11 is connected with an external bag-type dust collector, and the bag-type dust collector is connected with a draught fan; the third section dry inlet gas distribution chamber 12 is communicated with the fourth section dry outlet gas distribution chamber 17 through a second hot blast circular duct 14; the fourth section drying inlet gas distribution chamber 15 is connected with a hot air outlet of the hot air furnace through a hot air inlet pipe 16; the cold air inlet gas distribution chamber 18 is connected to a cold air inlet pipe 20; the lower parts of all the gas distribution chambers are respectively connected with a powder discharge valve 6 through pipelines.

In order to facilitate redistribution of dried materials and prevent air channeling among drying sections, the 1 st to 4 th drying sections are respectively provided with a plurality of conical hoppers 23 at the lower parts of the drying sections, all the gas distribution chambers are respectively provided with a distribution chamber perforated plate 22 to be separated from the drying cavity 3, the distribution chamber perforated plate 22 is provided with a plurality of conical holes, the small holes of the conical holes face the drying cavity 3, the large holes of the conical holes face the gas distribution chamber, and the aperture of the small holes is smaller than the particle size of the materials.

The drying chamber 3 is not provided with a transmission device, and the whole material is driven to move downwards by the gravity of the material and the movement of the conveying belt 21, and the discharging speed is controlled.

In the embodiment, the half-dried bentonite cat litter after granulation is dried, the particle size of the cat litter is 2-4 mm, the specification of a bag-type dust collector is 64-5, and a 9-19-12D high-pressure fan is selected as a fan. The reason why the semi-dry cat litter is dried in this embodiment is: the water content of the granulated cat litter is 30%, the hardness of the cat litter is insufficient, and the cat litter is high in material level and easy to crush and deform.

The specification of the drying device of the embodiment is as follows: the drying cavity 3 is 7.0 meters in total height, 1.5 meters in width and 0.14 meters in thickness; the length of the flower plate of the distribution chamber is 1.5 meters multiplied by 1.0 meter, and the aperture of the flower hole plate 22 of the distribution chamber is 1.8 mm.

The working flow of the drying device adopting the embodiment is as follows:

1. the hot air supply source of the embodiment is a hot air furnace, and the bag-type dust collector and the induced draft fan are started after the hot air furnace burns normally.

2. When the outlet temperature of the drying flue gas outlet pipe 11 reaches 70 ℃, the disc granulator is started, the running speed of the conveyer belt 21 is adjusted, and the device is in a normal working state.

3. Cat litter carries out drying chamber 3 from hopper 1 after the granulation, cold air gets into cold air inlet gas distribution room 18 by cold air import pipe 20 simultaneously, distribution room flower hole board 22 through cold air inlet gas distribution room 18 gets into corresponding cooling zone and hot material and carries out the heat exchange, the material is cooled off, cold air becomes hot-air, hot-air is in proper order through hot-air outlet gas distribution room 19, heat transfer hot-blast main 7, first section dry inlet gas distribution room 5 introduces 1 dry section and carries out the drying to the material, hot-air temperature drops after the drying, discharge the sack cleaner from heat transfer air drying outlet pipe 4 through first section dry outlet gas distribution room 2, discharge by the draught fan outward again.

4. Hot air from the hot blast stove in the step 2 enters a fourth-section drying inlet gas distribution chamber 15 from a hot air inlet pipe 16, then enters a 4 th drying section through the fourth-section drying gas inlet distribution chamber 15 to dry the material, then the hot air sequentially enters a fourth-section drying gas outlet distribution chamber 17, a second hot air ring pipe 14 and a third-section drying gas inlet distribution chamber 12 to enter a 3 rd drying section to dry the material, the gas passing through the 3 rd drying section sequentially enters a third-section drying gas outlet distribution chamber 13, a first hot air ring pipe 10 and a second-section drying gas inlet distribution chamber 8 to enter a 2 nd drying section to dry the material, the gas passing through the 2 nd drying section enters a second-section drying gas outlet distribution chamber 9 and then is discharged into a bag-type dust collector through a drying flue gas outlet pipe 11, and then is discharged out through a draught fan.

5. The cat litter of step 1 gets into each drying section from top to bottom through hopper 1, and each drying section is equallyd divide and is established the toper fill 23 respectively, and the material obtains the distribution again through toper fill 23, and the material gets into the cooling section and discharges from drying chamber 3 after cooling according to step 3 and send to the storage tank through conveyer belt 21.

This example is to the product after the cat litter after the granulation is dried:

1. when the temperature of the smoke outlet is 70 ℃, the moisture of the cat litter product is 2.84%.

2. The cat litter product has complete particles and no deformation.

3. The cat litter product has no dust, the product reaches the dust-free level, and the product does not need to be dedusted.