JP4319338B2 - Continuous atmospheric pressure superheated steam drying method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous atmospheric pressure superheated steam drying method and apparatus for continuously drying an object to be dried in a closed circuit system of atmospheric pressure superheated steam.
[0002]
[Prior art]
Recently, companies are required not only to prevent pollution and reduce waste, but also to take a more proactive approach to the realization of a recycling society with a view to improving the environment.
For example, in food processing and manufacturing plants, in addition to conventional energy cost reductions, odor countermeasures, reuse of fertilizers and fuels, etc., wastes are further recycled to food, feed, etc. It is required to recycle it as a raw material and to achieve more desirable recycling.
[0003]
Conventionally, as a method for drying a material to be dried such as a raw material or a residue, a hot air drying method in which outside air is introduced and heated to raise the temperature to hot air, and the moisture of the material to be dried is vaporized and evaporated by this heat has been mainly used. .
The hot air drying method is a method of moving moisture from the material to be dried into the hot air and drying it, and in order to prevent pollution and effectively use heat, use a technology that cools, dehumidifies and reheats with a heat exchanger, In many cases, hot air is circulated and a part is heated and sucked and a part is exhausted.
[0004]
However, the hot air drying method has been difficult to treat odor of exhaust gas generated in large quantities.
Biodegradation methods, thermal decomposition methods, etc. are known as odor treatment techniques, but biodegradation methods with lower energy costs may vary in performance depending on the material to be dried. On the other hand, the thermal decomposition method has a high energy cost because the temperature is 600 ° C. or higher. Either method has a problem that the initial cost of the equipment increases.
[0005]
The hot air drying method generally uses a high temperature at the initial stage in the drying process and a low temperature of about 80 ° C. in the latter stage in order to prevent the quality of the material to be dried from being denatured by heat. Progressing from the surface of the material to be dried and forming a hard dry cortex on the surface, the internal drying is inhibited.
In other words, the hot air drying produces a hard dry cortex on the surface of the object to be dried, and the quality of the object to be dried is lowered along with the oxidation of the surface.
[0006]
Furthermore, in the hot air drying method, the temperature of the object to be dried does not rise above the wet bulb temperature when moisture evaporates during drying, so that complete sterilization and sterilization are not performed.
In addition, in order to completely dry and sterilize the inside of the object to be dried, when the latter stage of the drying process is set to a high temperature, the surface of the object to be dried that has already been dried not only deteriorates but deteriorates in quality. If the surface of the dried product is oxidized, there is a problem that scorching and self-ignition (spontaneous ignition) occur.
[0007]
In order to eliminate the above points, sulfur gas, methyl bromide, EO (ethylene oxide) gas, ozone, etc. have been used for sterilization and sterilization of the objects to be dried. Recently, its use is being restricted.
[0008]
Closed circuit type (closed type) that circulates hot air as a type of hot air drying method removes water vapor by cooling and dehumidification of hot air, so there is no exhaust gas and the problem of odor treatment can be solved. Depending on the degree of cooling, simply adjusting the amount of water vapor in the hot air will leave the problem of dry film and sterilization / sterilization.
[0009]
On the other hand, the high-temperature and high-humidity drying method, which is dried at a high temperature (400 to 600 ° C.) and with high-humidity hot air, can continuously dry a large amount of an object to be dried, as compared with the conventional hot-air drying method, By using high-temperature, high-humidity hot air close to a water vapor atmosphere, the drying speed is fast and the drying apparatus can be miniaturized.
[0010]
Further, the high-temperature and high-humidity drying method is excellent in thermal efficiency because the exhaust gas is circulated and used, and the exhaust gas having a high humidity and close to boiler steam can be used as a heat source of the waste heat recovery apparatus.
[0011]
Furthermore, since the high-temperature and high-humidity drying method releases only the combustion product gas and evaporated water vapor to the atmosphere, the amount of exhaust gas can be significantly reduced as compared with the conventional hot-air drying method.
[0012]
However, in the high-temperature and high-humidity drying method, steam evaporated from the material to be dried is added to create a mixed gas state of hot air and superheated steam. The steam volume ratio is different between the inlet and outlet of the dryer, and is limited to 0.5 to 0.8 kg (water vapor) / kg (air). At the start and end of the drying process, normal hot air drying is performed. The same processing method is used.
In other words, hot air drying creates a hard dry cortex on the surface of the object to be dried, which not only degrades the quality of the object to be dried together with oxidation of the surface, but also exceeds the wet bulb temperature at the time of evaporation of moisture during drying. Since the temperature of the object to be dried does not rise, there is a problem that complete sterilization and sterilization cannot be performed.
[0013]
In addition, the high-temperature and high-humidity drying method tends to cause modification of the material to be dried at the start and end of the operation of the drying process, and the denatured material (such as scorch) generated thereby stays in the dryer. There has been a problem that the modified product is mixed into the product (dried product).
[0014]
Furthermore, since the high-temperature and high-humidity drying method is semi-closed circuit drying, it is difficult to oxidize the object to be dried and to treat the exhaust gas odor by inflow of air into the dryer.
[0015]
[Problems to be solved by the invention]
The present invention has been made in view of such problems of the prior art. The object of the present invention is to improve the quality of the object to be dried without discharging the odor generated from the object to be dried to the outside of the drying apparatus. The present invention provides a continuous atmospheric pressure superheated steam drying method and apparatus that can sterilize and sterilize the material to be dried, can be dried to the inside of the material to be dried, and further save energy and have a low running cost. is there.
[0016]
[Means for Solving the Problems]
That is, according to the present invention, there is provided a continuous atmospheric pressure superheated steam drying method for continuously drying an object to be dried in a closed circuit system of atmospheric pressure superheated steam, wherein the drying is performed by raising the temperature to a predetermined temperature and stabilizing it. Spray water is introduced into the oven, water vapor is generated, air and water vapor are circulated and heated, and the air in the dryer is sufficiently replaced with superheated water vapor, and then the material to be dried is introduced into the dryer. The dried material is continuously dried while circulating the superheated steam so that the superheated steam atmosphere in the dryer is maintained at a constant condition, and the dried material staying in the dryer is dried. A continuous atmospheric pressure superheated steam drying method is provided, wherein the method is discharged to the outside of the vessel.
[0017]
At this time, the spray amount of water is preferably 2 to 20 times the dry chamber volume in the vaporization volume.
[0018]
Moreover, in this invention, it is preferable to introduce | transduce water vapor | steam into a dryer, circulate and heat air and water vapor | steam, and to replace the air in a dryer with superheated water vapor | steam.
At this time, the amount of water vapor is preferably 2 to 20 times the volume of the drying chamber.
[0019]
Furthermore, in this invention, it is preferable that the temperature of superheated steam is 100-400 degreeC.
[0020]
According to the present invention, there is also provided a continuous normal pressure superheated steam drying apparatus for continuously drying an object to be dried in a closed circuit system of normal pressure superheated steam. A dryer for drying a material to be dried in an overheated steam atmosphere by circulation, and steam supplied from a steam supply means for generating steam from hot air and spray water supplied from the water spray means in the dryer Circulated and heated in the dryer, superheated steam supply means for supplying superheated steam into the dryer, heat exchanger for heating the superheated steam circulating gas introduced into the dryer, and the dryer And a condenser for condensing surplus water vapor accompanying water evaporation of the material to be dried generated from the continuous atmospheric pressure superheated steam drying apparatus.
[0021]
At this time, in the present invention, it is preferable that the condenser is provided outside the closed circuit system of atmospheric superheated steam, and the closed circuit system and the outside air are continuously communicated via the condenser.
[0023]
In the present invention, the water spraying means is preferably a two-fluid nozzle or a spray nozzle having a pressure spiral structure.
[0024]
Furthermore, in this invention, it is preferable that a dryer is a rotary dryer, and it is more preferable that a rotary dryer has a crushing stirring blade.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The continuous atmospheric pressure superheated steam drying method in the present invention will be described.
FIG. 1 is a timing chart showing an example of the drying method of the present invention (rotary cylinder type drying apparatus + water spray type). The water spray during the superheated steam replacement period and the residue discharge period also show the results from the material to be dried. It is characterized in that the amount of water corresponding to water evaporation is sprayed with water.
FIG. 2 is a timing chart showing another example of the drying method of the present invention (fluidized bed drying apparatus + steam supply type). In the steam supply during the superheated steam replacement period and the residue discharge period, the excess condenser is used. It is characterized by maintaining the superheated steam atmosphere in the dryer while suppressing the condensation of water vapor and lowering the inlet chamber temperature.
[0026]
That is, the drying method of the present invention is mainly characterized in that the object to be dried is continuously dried in a closed circuit system of superheated steam (100 to 400 ° C.) as shown in FIGS. After sufficiently replacing the air inside with superheated steam, the material to be dried is introduced into the dryer, and continuously heated while circulating the superheated steam so that the superheated steam atmosphere in the dryer is maintained at a constant condition. It is important to dry the dried product and discharge the material to be dried staying in the dryer under a superheated steam atmosphere to the outside of the dryer.
[0027]
As a result, the drying method of the present invention uses a superheated steam without discharging the odor generated from the object to be dried to the outside of the drying apparatus because the heating medium gas is a closed circuit, thereby improving the quality of the object to be dried. The object to be dried can be sterilized and sterilized while being maintained, and can be dried to the inside of the object to be dried. Further, energy saving and low running cost are achieved.
[0028]
Here, in the drying method of the present invention, it is important to continuously dry the material to be dried in an atmosphere occupied by almost 100% superheated steam at normal pressure.
Note that the atmosphere occupied by the normal pressure superheated steam exhibits an “oxygen-free state” because the air partial pressure is almost “zero” and almost no air is present.
In order to maintain such an atmosphere in the dryer under certain conditions and maintain an oxygen-free state continuously, it is important to continue introducing superheated steam with a minute positive pressure and a high flow rate into the dryer. is there.
[0029]
For this reason, in this invention, it is preferable to reheat the superheated steam used for drying with a heat exchanger, to recirculate in a dryer, or to condense excess steam.
[0030]
In the present invention, steam may be directly introduced into the dryer. However, when the volume of the dryer is large (for example, a rotary dryer), superheated steam is generated from hot air and spray water in the dryer. It is more preferable to generate it because the thermal efficiency can be improved.
[0031]
The drying method using superheated steam is a drying method using steam (dry steam) having a drying ability at a temperature higher than the saturated steam temperature. Water vapor is saturated water vapor at less than 100 ° C. and does not have a drying ability. However, when it reaches 100 ° C. or higher, it has a drying ability. The higher the temperature, the higher the drying speed, and the easier it is to dry the article. There is a temperature (reversal point temperature) at which the drying rate of superheated steam is higher than that of heated air drying at a steam temperature of about 150 ° C to 180 ° C.
That is, the superheated steam is steam that is superheated to 100 ° C. or higher (usually 100 to 400 ° C.) while maintaining saturated steam evaporated at 100 ° C. at normal pressure.
[0032]
The feature of drying with superheated steam is that the drying chamber can be filled with water vapor, so that there is no cortex formation due to oxidation of the material to be dried or hardening of the surface of the material to be dried. Since the product temperature is maintained at about 100 ° C., sterilization, sterilization, and enzyme deactivation can be performed up to the inside of the material to be dried.
[0033]
In the drying method of the present invention, it is important to perform the superheated steam of the heat medium gas in a closed circuit system.
As a result, there is no inflow of air into the drier or outflow of exhaust gas to the outside of the drier during the drying process, so that the object to be dried is not oxidized by oxygen, and the odor generated from the drier is released to the outside. Since it does not discharge, it can contribute to environmental improvement. Excess steam (evaporated steam and odor generated from the material to be dried, etc.) is collected as condensed water by a condenser and is subjected to wastewater treatment.
[0034]
Furthermore, in the drying method of the present invention, it is important that the material to be dried staying in the dryer from the stoppage of the material to be dried to the operation stop is discharged outside the dryer in a superheated steam atmosphere. .
Thereby, since the to-be-dried material staying in the dryer can be reliably discharged without being denatured, it is possible to prevent the denatured product from being mixed into the product during the next drying process.
[0035]
Hereinafter, the continuous atmospheric pressure superheated steam drying method and apparatus of the present invention will be described with reference to the drawings.
FIG. 3 shows an example of the drying apparatus of the present invention, in which (a) is a schematic diagram, and (b) is a detailed view of the main part of (a).
In the drying method in FIG. 3, first, hot air heated by the heat exchanger 20 is introduced into the dryer 1 so that the temperature inside the dryer 1 is raised and stabilized, and then introduced into the dryer 1. The steam is generated from the hot air and the spray water sprayed from the water spray means 10, the air in the dryer and a part of the steam are circulated and heated, and a part of the steam is exhausted via the condenser. The air in 1 is replaced with superheated steam (100 to 400 ° C.).
At this time, the amount of spray water is preferably 2 to 20 times the volume of the drying chamber in terms of vaporization volume.
[0036]
Next, the material to be dried is charged from the charging hopper 16 into the dryer 1 filled with superheated steam, and the material to be dried is continuously dried in the superheated steam atmosphere.
As soon as the material to be dried is put into the dryer 1, it is lifted from the drum bottom to the top of the drum by the lifter 5 mounted in the rotating drum, and crushing and stirring that rotates at high speed while dropping from there. The movement crushed by the blade 3 is repeated to the vicinity of the outlet, and efficiently contacts with the superheated steam (see FIG. 5).
Also, if the material to be dried is a large lump, it will be crushed into small lumpes, and the moist surface will appear one after another and come into contact with superheated steam, and the small lump will be further pulverized to become granular and cascade (falling waterfalls will fall and fall) Then, it is further dried and becomes a dried product with almost uniform particle size, and is discharged from the outlet chamber 8.
[0037]
At this time, in order to maintain the superheated steam atmosphere in the dryer 1 at a constant condition, the superheated steam used for drying is reheated in the heat exchanger 20 and then circulated in the dryer 1.
[0038]
Of the superheated steam discharged from the dryer 1, surplus steam (evaporated steam and odor generated from the material to be dried, etc.) accompanying the water evaporation of the material to be dried is recovered as condensed treated water by the condenser 30. Wastewater treatment.
Further, the dried product (product) discharged from the dryer 1 is taken out by the product conveying means 18.
[0039]
And after discharging the to-be-dried material from the stop of the operation to the operation stop, the to-be-dried material staying in the dryer 1 is discharged to the outside of the dryer 1 in the superheated steam atmosphere, and then the inside of the dryer 1 Replace the superheated steam with air.
[0040]
4A and 4B show another example of the drying apparatus of the present invention, in which FIG. 4A is a schematic view, and FIG. 4B is a detailed view of the main part of FIG.
The difference from the drying apparatus of FIG. 3 is that in FIG. 4, water vapor is directly introduced into the dryer 1 instead of the water spray means 10.
At this time, the temperature of the superheated steam is preferably 100 to 400 ° C., and the amount of steam is preferably 2 to 20 times the volume of the drying chamber.
[0041]
Here, the water spray means 10 used in FIG. 3 is a two-fluid nozzle that sprays the water sent from the water supply equipment 11 together with the air from the blower equipment 12 or a pressure type spiral that pressurizes and sprays only water. It is preferable to use a spray nozzle having a structure.
[0042]
The two-fluid nozzle is, as described in Japanese Patent No. 2524379 already acquired by the applicant of the present application and Japanese Patent Application Laid-Open No. 4-281872, and a high-speed gas provided around the pressure swirling nozzle for liquid ejection. Examples thereof include a cylindrical body for blowout and a tapered structure at the tip. In this spray nozzle, there are two atomization stages. First, primary atomization is performed with the pressure of the liquid of the pressure swirl nozzle itself. In this primary atomization, the liquid is jetted in a conical shape.
Next, even when the liquid is sprayed at a low pressure by causing the high-speed gas blown from the blow-out cylindrical body to collide intensively with the primary atomized droplets to make secondary atomization, Not only can atomization of the liquid be achieved, but also the droplet diameter can be controlled.
[0043]
In the apparatus of the present invention, it is preferable that the condenser 30 is provided outside the closed circuit system of atmospheric superheated steam, and the closed circuit system and the outside air are continuously communicated via the condenser.
That is, in the apparatus of the present invention, when the closed circuit system is at normal pressure, the pressure is adjusted so that there is no pressure difference between the closed circuit system and the condenser. When the closed circuit system becomes negative pressure, the outside air is supplied from the condenser 30 to the closed circuit system to automatically maintain the closed circuit system at normal pressure. it can.
At this time, it is preferable to control the fine pressure adjusting damper 24 in conjunction with the pressure sensor so that the pressure in the dryer 1 becomes a fine plus pressure.
Further, since the device of the present invention adjusts the pressure of the closed circuit system as in the prior art, it is not necessary to open and close the pressure regulating valve (not shown), so that a sudden positive pressure or negative pressure is generated in the closed circuit system. Even if this occurs, damage to the device (particularly the dryer 1) can be greatly suppressed.
[0044]
Furthermore, the dryer 1 used in the present invention is not particularly limited and can be applied to a fluidized bed, spraying, airflow, ventilation, etc., but it is preferably used as appropriate depending on the properties of the material to be dried.
[0045]
Here, it is more preferable that the dryer 1 used in the present invention is a rotary dryer with a crushing stirring blade (see FIGS. 3 to 4).
This is because the overall heat transfer coefficient is large due to the synergistic effect of the crushing stirring blade and the drum rotation, so that the apparatus can be miniaturized, and the crushing stirring blade crushes the material to be dried, thereby reducing the contact area with the superheated steam. This is because not only the superheated steam can be used effectively and the fuel consumption is economical, but also the material to be dried can be used in a wide range from a paste to a pulverized product.
[0046]
In the drying apparatus of the present invention, the rotating body and the fixed entrance / exit hood are connected in order to prevent the blowing of superheated steam to the outside, the inflow of outside air, the generation of dust, the contamination of the dried product (product), etc. It is important to air-seal the discharge port of the charging hopper, dry matter, etc., for example, with an airtight device 9 as shown in FIG.
[0047]
【Example】
The present invention will be described in more detail based on examples, but the present invention is not limited to these examples.
(Example)
FIG. 1 shows a drying test of corn residue for saccharification, so-called corn jam, as a raw material (substance to be dried) using the rotating cylindrical drying apparatus (diameter 1.15 m, length 9.4 m) shown in FIG. Based on the timing chart.
[0048]
First, the temperature of the inlet 1 in the dryer 1 is raised to 300 ° C., and a steam spray type two-fluid nozzle (water spray means 10) is used to spray 100 kg with a total amount of water at a spray water amount of 200 to 600 kg / h for 15 minutes. (This corresponds to an amount of evaporated vapor about 10 times the total capacity of the dryer 1), thereby generating water vapor in the dryer 1.
Next, a part of the air and water vapor in the dryer 1 is circulated and heated, and a part thereof is exhausted through the condenser 30 to replace the air in the dryer 1 with superheated water vapor. Was kept in a steady state.
[0049]
By continuously performing superheated steam drying (inlet temperature: 300 ° C., outlet temperature: 140 ° C.) while supplying a raw material having a moisture content of 67% into the dryer 1 at 1300 kg / h, a moisture content of 4 5% product (dry product) could be processed at 448 kg / h.
[0050]
After the above steady operation was performed for 8 hours, the raw material supply was stopped, and water spraying (400 kg / h) was immediately performed.
Twenty minutes later, it was confirmed that the product was completely discharged from the dryer 1, water spraying and heating of the circulating gas were stopped, the outside air introduction valve (not shown) in front of the circulation fan 26 was opened, and the above apparatus was Cooled and stopped.
[0051]
In the examples, the quality of the product (dried product) was stable from the beginning of operation to the completion of product discharge, and no burns were observed.
Further, in the examples, there was almost no odor from the exhaust gas, and particularly the odor was hardly felt even in the exhaust gas in the initial stage of operation.
The pressure gauge provided at the inlet of the dryer 1 changes in gauge pressure from 0.6 kPa (60 mmAq) to −0.1 kPa (−10 mmAq), and is 0.2 to 0 in steady operation. It was stable at 1 kPa.
[0052]
(Comparative example)
A corn jam drying test was performed by using substantially the same operation except for water spraying at the initial stage of operation and at the time of stopping using the same apparatus as in the example.
In the comparative example, the product moisture varied in the first 30 minutes and was partially solidified, but thereafter, the product moisture remained almost 4.5%.
In the comparative example, after the supply of the raw material is stopped, the inlet temperature is lowered from 300 ° C. to 200 ° C. in 5 minutes, and then the outside air is introduced to cool and stop the apparatus.
For this reason, the products after the supply of the raw material has a variation in the amount of moisture (the amount of moisture was about 15% in the mass portion), and not only a small amount of burnt product is discharged when the product is discharged. Odor was felt from the exhaust during the initial operation and when the operation was stopped.
[0053]
【The invention's effect】
As described above, according to the present invention, it is possible to sterilize and sterilize the material to be dried without discharging the odor generated from the material to be dried to the outside of the drying apparatus, while maintaining the quality of the material to be dried. Provided is a continuous atmospheric pressure superheated steam drying method and apparatus capable of sufficiently drying the inside of an object and further saving energy and having a low running cost.
[Brief description of the drawings]
FIG. 1 is a timing chart showing an example of a drying method according to the present invention (rotary cylindrical dryer + water spray type).
FIG. 2 is a timing chart showing another example of the drying method of the present invention (fluidized bed drying apparatus + water vapor supply type).
FIGS. 3A and 3B show an example of the drying apparatus of the present invention, in which FIG. 3A is a schematic view, and FIG. 3B is a detailed view of a main part of FIG.
4A and 4B show another example of the drying apparatus of the present invention, in which FIG. 4A is a schematic view, and FIG. 4B is a detailed view of the main part of FIG.
FIG. 5 is an explanatory diagram showing a drying process of a rotary dryer with a crushing stirring blade.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Dryer, 2 ... Drying material inlet, 3 ... Crushing stirring blade, 4 ... Crushing stirring shaft, 5 ... Lifter, 7 ... Inlet chamber, 8 ... Outlet chamber, 9 ... Airtight apparatus, 10 ... Water spraying means, DESCRIPTION OF SYMBOLS 11 ... Water supply equipment, 12 ... Blower equipment, 13 ... Hot air introduction equipment, 14 ... Superheated steam supply means, 16 ... Injection hopper, 17 ... Cyclone, 18 ... Product conveyance means, 20 ... Heat exchanger, 22 ... Hot air generator, 24 ... fine pressure adjusting damper, 26 ... circulating fan, 30 ... condenser, 32 ... cooling tower, 34 ... drain pump.

Claims (10)

A continuous atmospheric pressure superheated steam drying method for continuously drying an object to be dried in a closed circuit system of atmospheric pressure superheated steam,
After spray water is introduced into a dryer that has been heated to a predetermined temperature and stabilized, water vapor is generated, air and water vapor are circulated and heated, and the air in the dryer is sufficiently replaced with superheated water vapor. The material to be dried is introduced into the dryer, and the material to be dried is continuously dried while circulating the superheated steam so that the superheated steam atmosphere in the dryer is maintained at a constant condition. A continuous atmospheric pressure superheated steam drying method, characterized in that the material to be dried staying inside is discharged to the outside of the dryer. The continuous atmospheric pressure superheated steam drying method according to claim 1, wherein the amount of spray water is 2 to 20 times the volume of the drying chamber in terms of vaporization volume. The continuous atmospheric superheated steam drying method according to claim 1, wherein steam is introduced into the dryer, air and steam are circulated and heated, and the air in the dryer is replaced with superheated steam. The continuous atmospheric superheated steam drying method according to claim 3, wherein the amount of water vapor is 2 to 20 times the volume of the drying chamber. The temperature of superheated steam is 100-400 degreeC, The continuous-type normal-pressure superheated steam drying method of any one of Claims 1-4. A continuous atmospheric superheated steam drying apparatus for continuously drying an object to be dried in a closed circuit system of atmospheric superheated steam,
After replacing the air with superheated steam, by circulating the superheated steam, a dryer that dries the object to be dried in a superheated steam atmosphere; and
In the dryer, the steam supplied from the steam supplying means for generating steam from the hot air and the spray water supplied from the water spraying means is circulated and heated in the dryer to produce superheated steam in the dryer. Superheated steam supply means for supplying,
A heat exchanger for heating the superheated steam circulation gas introduced into the dryer;
A condenser that condenses excess water vapor accompanying water evaporation of the material to be dried generated from the dryer;
A continuous normal pressure superheated steam drying apparatus. 7. The continuous normal pressure superheated steam drying according to claim 6, wherein the condenser is provided outside the closed circuit system of normal pressure superheated steam, and the closed circuit system and the outside air are continuously communicated with each other through the condenser. apparatus. The continuous atmospheric superheated steam dryer according to claim 6, wherein the water spray means is a two-fluid nozzle or a spray nozzle having a pressure spiral structure. The continuous atmospheric superheated steam dryer according to any one of claims 6 to 8, wherein the dryer is a rotary dryer. The continuous atmospheric superheated steam dryer according to claim 9, wherein the rotary dryer has a crushing stirring blade.

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