TWI660148B - Drying method and drying system using horizontal rotary dryer - Google Patents

Abstract

An object of the present invention is to provide a horizontal rotary dryer which improves the drying capacity of the dryer and is easy to handle a large amount of the object to be processed.

The drying method using the horizontal rotary dryer of the present invention satisfies the following conditions.

(1) The inert carrier gas A is caused to flow in a cocurrent manner from one end side to the other end side in the rotating cylinder 10; (2) the carrier gas is heated at the other end side.

Description

Drying method and drying system using horizontal rotary dryer

The present invention relates to a drying method and a drying system using a horizontal rotary dryer.

Steam dryers (hereinafter referred to as "STDs"), coal tube dryers (Patent Documents) are often used as dryers for drying objects such as coal and ores. 1), and rotary kiln. Coal or ore is used as iron or refining raw materials, fuel for power generation, etc. Because these are required to be stable and processed in large quantities, the above-mentioned dryers have been adopted as dryers that meet the requirements.

Because STD indirectly heats the object to be processed, it has high thermal efficiency and a large amount of processing capacity per unit capacity. In addition, since it can be enlarged, it is suitable for a large number of processing requirements.

Because the coal tube dryer also indirectly heats the object to be treated, like the above-mentioned STD, it has high thermal efficiency and a large amount of treatment per unit capacity. However, compared with STD, it has the disadvantage that it is difficult to scale up. For example, when a coal tube dryer is used to process the above-mentioned amount that can be processed by one STD, a plurality of coal tube dryers may be required.

The rotary furnace directly heats the object to be dried by contacting it with the hot air. Therefore, compared with indirect heating, the rotary furnace has the disadvantage of poor thermal efficiency. It also has the disadvantage that the exhaust gas treatment equipment is abnormally large. For various reasons, STD has more advantages as a dryer for processing a large number of objects to be processed.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Utility Model Registration No. 2515070

In recent years, the requirements for a large number of drying treatments of objects to be treated have been increasing. In order to comply with the requirements, the size of dryers has been continuously increased. Taking the enlargement of STD as an example, a case with a diameter of 4m and a body length of 30m or more has been manufactured.

On the other hand, when using large STDs or small STDs to dry coal, resin raw materials, etc., which may be burned by fire, the carrier gas containing inert gas such as N ₂ gas can be filled with STD. Measures to prevent the incorporation of oxygen in the conveying system of the object to be processed and the dried object.

In addition, inert gas such as N ₂ gas is circulated so that water or volatile component vapor scattered by heating operation does not reach the dew point, and water or volatile components are condensed and removed in the circulation system. Outside the system, inert gases such as N ₂ gas are used for recycling.

However, the following problems remain as the main reason. First: Although the required circulation amount of inert gas also depends on the scale of the equipment, as for large equipment, the fans or pipes on the circulation path are also large, so the power consumption and equipment costs are high.

Second: Because the water or volatiles in the circulation system are condensed, cooling water is generally used, so the gas temperature is mostly 20 ° C ~ 50 ° C.

In order to reduce the capacity of the wet gas of the circulation system, it is necessary to reduce the capacity of the inert gas to be circulated.

In this case, if the temperature of the exhaust gas from the dryer flowing into the condenser is raised and the dew point is raised, the problem can be solved theoretically.

However, due to the limitation of product temperature (for preventing dew condensation on the surface of the object to be treated) and saturation gas, dew condensation due to heat dissipation or the like becomes a problem.

In large STDs, if the filling rate of the object to be processed is large, the filling part becomes overheated. If the cooling on the gas side and the movement of the evaporated steam are less, the dew point will rise, leading to exhaustion. Dew condensation occurs on the exit side.

Depending on the type of dry matter, in most cases, this condensation state must be avoided as much as possible. Examples of this include coal or some resin raw materials.

Therefore, the main object of the present invention is to provide a drying method using a horizontal rotary dryer which can prevent dew condensation and reduce the amount of carrier gas.

The method of the present invention for solving the above problems is as follows.

A drying method using a horizontal rotary dryer, wherein the horizontal rotary dryer is provided with a supply port having an object to be processed at one end side, an outlet port having an object to be processed at the other end side, and a shaft center. A freely rotating rotating tube is provided with a plurality of heating tubes in the rotating tube through which the heating medium passes. During the process of supplying the object to one end side of the rotating tube and discharging from the other end side, the heating tube is used for heating. The object to be processed is dried; the drying method using a horizontal rotary dryer is characterized by satisfying all of the following conditions: (1) The inert carrier gas is co-currently flowed from the one end side to the other end side in the rotating drum. (2) heating the carrier gas on the other end side of the rotating cylinder.

The drying method of the present invention further desirably satisfies the conditions of setting the product temperature of the discharged dried product to 95 ° C or higher and the temperature of the discharge side of the carrier gas to 95 ° C or higher.

The system of the present invention is as follows.

A drying system using a horizontal rotary dryer, wherein the horizontal rotary dryer is provided with a supply port having an object to be processed at one end side, an outlet port having an object to be processed at the other end side, and a shaft center. A freely rotating rotating tube is provided with a plurality of heating tubes in the rotating tube through which the heating medium passes. During the process of supplying the object to one end side of the rotating tube and discharging from the other end side, the heating tube is used for heating. The object to be processed is dried; the characteristics of the drying system using the horizontal rotary dryer include: (1) a mechanism for circulating an inert carrier gas in the rotating cylinder in a co-current manner from the one end side to the other end side; and (2) a heating mechanism for heating the carrier gas provided at the other end side of the rotating cylinder.

As this heating mechanism, a heating trace provided on the other end side of the rotating tube can be used.

In addition, as the heating mechanism, a jacket structure provided on the other end side of the rotating cylinder to circulate the heating medium may be used.

Furthermore, the heating mechanism may be a fin provided on the other end side of the heating tube.

In addition to the above conditions, a holder may be provided on the other end side.

The dew condensation problem mainly occurs on the discharge side (the other end side of the rotating cylinder).

In the present invention, it is set to a co-current method in which an inert carrier gas is allowed to flow from one end side to the other end side in a rotating cylinder.

In the case of convection, the temperature of the carrier gas is about 20 ~ 40 ° C. Therefore, in addition to the problem that the evaporated component at the supply inlet of the object to be treated is condensed and attached to the object to be dried due to the decrease of the exhaust gas temperature, It is also difficult to increase the gas temperature and product temperature.

In addition, according to the co-current method, the exhaust gas temperature and product temperature can be increased even with a small amount of carrier gas.

Furthermore, in the present invention, the temperature of the product to be discharged is set to 95 ° C or higher, preferably 97 ° C or higher, more preferably 99 ° C or higher, and the temperature of the discharge side of the carrier gas is set to 95 ° C. The temperature is preferably 97 ° C or higher, and more preferably 99 ° C or higher, so that condensation does not easily occur.

However, although the dew point of the carrier gas can be set to 95 ° C or higher to reduce the amount of the carrier gas according to these conditions, on the other hand, since the dew point is about 97 ° C, even a minute heat radiation portion may become a dew condensation area.

Therefore, the exhaust gas is improved by the heating mechanism for heating the carrier gas at the other end. Air temperature to prevent condensation.

Here, the temperature of the product to be dried and / or the temperature of the discharge side of the carrier gas was set to 95. The case above ℃ will be supplementary explained.

Table 1 is a part of the absolute temperature table. The amount of water vapor xs contained in the 1 kg of dry air in the table increases with the increase in temperature t, but the amount of water vapor xs is 1000 g / kg at 87 ° C. In contrast, it suddenly increased to 95 ° C It was about 3.1 times, it suddenly increased to about 5.5 times at 97 ° C, and it increased to about 17 times at 99 ° C. This means that if the temperature is increased, more steam can be included in a certain air volume, and the content will be significantly increased when it is above 95 ° C.

In addition, in the past, taking into account the fact that dew condensation is certainly prevented, the air volume of the carrier gas and the product temperature of the dry matter are set based on the water vapor amount xs (g / kg) in the range of 85 ° C to 87 ° C.

In contrast, by setting the product temperature of the dried product and / or the temperature of the discharge side of the carrier gas to 95 ° C or higher, the dew point can be increased to reduce the air volume of the carrier gas used to exhaust the necessary moisture. However, the problem that the condensation occurs in a delicate area as described above becomes a problem arises. However, according to the present invention, dew condensation can be prevented by providing a heating mechanism for heating the carrier gas on the other end side of the rotating cylinder.

In addition, the product temperature of the discharged dry matter of the present invention refers to the temperature of the dry matter that has just been discharged from the discharge port of the rotary drum.

The temperature on the discharge side of the carrier gas refers to the temperature of the carrier gas that has just been discharged from the gas discharge port of the rotary cylinder.

Furthermore, the "other end side" of the present invention means that the total length from the other end of the rotating cylinder to the entire length is less than 50%. Preferably, based on the inner diameter D of the rotating cylinder, the length from the center of the discharge opening from which the dried matter is discharged to one end of the supply port where the object to be processed is formed is at most (0.5 to 3.5) D. It is more desirable to have a length range of at most (0.5 to 2.0) D.

If the length of the heating mechanism is short, the heating is insufficient. If the length of the heating mechanism is too long, the heating energy consumption is increased, and the equipment cost is also high.

As described above, according to the present invention, dew condensation can be prevented and the amount of carrier gas can be reduced.

10‧‧‧ rotating tube

11‧‧‧ heating tube

12‧‧‧ jacket

12A‧‧‧Companion pipe

12B‧‧‧ Fin

13‧‧‧ retainer

17‧‧‧End plate section

20‧‧‧ Support Unit

20, 20‧‧‧ Hoop members

21‧‧‧ opening

22‧‧‧ opening

23‧‧‧ partition

24‧‧‧ Spiral Blade

30‧‧‧Motor unit

32‧‧‧Exhaust

33‧‧‧ Carrier gas outlet

34‧‧‧ supply port

35‧‧‧ cover

41‧‧‧Supply

42‧‧‧Screw feeder

44‧‧‧ Spiral

45‧‧‧Suction box

46‧‧‧Supply Chute

48‧‧‧Vibration motor

50‧‧‧Exhaust

55‧‧‧Grading hood

56‧‧‧ fixed exhaust port

57‧‧‧Fixed outlet

60‧‧‧Lifting board

61‧‧‧Internal steam supply pipe

62‧‧‧Internal drain pipe

63‧‧‧rotary joint

65‧‧‧mixing mechanism

70‧‧‧Steam supply pipe

71‧‧‧Drain tube

72‧‧‧Gas tube

80‧‧‧shell

A‧‧‧ carrier gas (inert gas)

C‧‧‧ fine particles

D‧‧‧Inner diameter of rotating tube

D‧‧‧ Condensate

E‧‧‧ Treatment

E‧‧‧ Dry

E‧‧‧ Dry treatment

R‧‧‧ direction

S‧‧‧Heating media

STD‧‧‧Horizontal Rotary Dryer

U1‧‧‧ send out channel

U2‧‧‧Gas channel

W‧‧‧ Object

Fig. 1 is a perspective view of an example of a horizontal rotary dryer of the present invention.

Fig. 2 is a side view of an example of a horizontal rotary dryer of the present invention.

Fig. 3 is a side view showing the screw feeder and its periphery.

Fig. 4 is an enlarged view (side view) of the other end side of the rotating cylinder.

Fig. 5 is a side view of a horizontal rotary dryer (modified example) of the present invention.

Fig. 6 is a sectional view taken along the line X-X in Fig. 5.

Fig. 7 is a side view when the supply method is a spray type.

Fig. 8 is a side view of the case where the feeding method is a vibration conveying trough type.

Fig. 9 is a side view showing a structural example of a discharge side of the rotary cylinder.

Fig. 10 is a cross-sectional view showing an example of the arrangement (first arrangement form) of the heating tubes of the horizontal rotary dryer.

FIG. 11 is a cross-sectional view showing an example of the arrangement (second arrangement form) of the heating tubes of the horizontal rotary dryer.

Fig. 12 is a diagram for explaining the generation of dew condensation.

FIG. 13 is a schematic diagram of an example of a jacket setting.

FIG. 14 is a schematic diagram of an example of the installation of the pipe piping.

FIG. 15 is a schematic diagram of an example of fin formation.

16 (a) and 16 (b) are schematic diagrams of an example of a fixture installation.

Hereinafter, a preferred embodiment of the present invention will be further described using drawings. In addition, the following description and drawings are merely examples showing an embodiment of the present invention, and the content of the present invention should not be construed as being limited to this embodiment.

(To-be-processed object W)

First, the object W to be dried is not limited. Specific examples thereof include ores and metal substances such as coal, copper ore, iron powder, and zinc powder; gypsum, alumina, and soda ash. Inorganic substances; or dehydrated sludge.

However, the effect of the present invention is particularly significant when the coal is dried.

(Indirect heating horizontal rotary dryer)

Next, a horizontal rotary dryer (hereinafter, also referred to as "STD (Steam Tube Dryer)") of the present invention will be described. As shown in FIG. 1 and FIG. 2, the horizontal type The structure of the rotary dryer includes a cylindrical rotating drum 10, and the axial direction of the rotating drum 10 is slightly inclined with respect to the horizontal plane; one end of the rotating drum 10 is located higher than the other end. Below the rotating tube 10, two supporting units 20 and a motor unit 30 are provided to support the rotating tube 10, and the rotating tube 10 is set to rotate freely around its own axis by the motor unit 30. The rotating cylinder 10 is rotated in one direction. This direction can be arbitrarily determined. For example, when the other end side (the discharge port side of the processing object W) is viewed from one side (the supply port side of the processing object W), it can be rotated in a counterclockwise direction (the direction of the arrow symbol R).

A plurality of steam tubes (heating tubes) 11 made of a metal tube are used as heat transfer tubes for the object to be dried W inside the rotating tube 10. The plurality of heating tubes extend along the axis of the rotating tube 10. The heating tubes 11 are arranged in the circumferential direction and the radial direction one by one, for example, so as to form a concentric circle with respect to the axial center of the rotating tube 10. This heating pipe 11 is heated by making the steam of the heating medium equal to the circulation inside the heating pipe 11.

A gas blowing mechanism (not shown) for blowing a carrier gas A (inert gas) into the rotary cylinder 10 from the supply port 41 near the screw feeder 42 is provided, and a carrier blown by the gas blowing mechanism The gas A flows through the inside of the rotating cylinder 10 toward the other end side of the rotating cylinder 10.

As shown in FIGS. 2 and 4, a plurality of discharge ports 50 are formed through the peripheral wall of the other end side of the rotating cylinder 10. A plurality of discharge ports 50 are formed along the circumferential direction of the rotating cylinder 10. In the example of FIGS. 2 and 4, the discharge ports 50 are formed to be spaced apart from each other in two rows. Although the plurality of discharge ports 50 are all formed in the same shape, they may be formed in different shapes.

In addition, as shown in FIG. 1, it is desirable that the processed object E is discharged downward through a hood 35 having a discharge port under the cover 50 group of discharge ports.

A steam supply pipe 70 and a drain pipe 71 for supplying steam in the steam pipe 11 are provided on the other end side of the rotary cylinder 10.

In addition, a stirring mechanism (the detailed structure is not shown) may be provided inside the other end side of the rotating cylinder 10 to stir the object to be processed W.

In addition, as shown in FIG. 5 and FIG. 6, the rotating cylinder 10 may be covered with a plurality of rows. The other end of the outlet 50 is provided with a classification cover 55 capable of discharging the object W and the carrier gas A. The classification cover 55 is formed of, for example, a thick-walled metal, and has a fixed discharge port 57 for discharging the dried and classified processed object W, that is, a processed object E, on the bottom surface, and a fixing for discharging the carrier gas A on the top plate. Exhaust port 56.

(Drying process)

Next, a process of drying the object W to be treated with the horizontal rotary dryer will be described with reference to FIGS. 1 to 4.

The object to be processed W is supplied into the screw feeder 42 from the supply port 41, and a screw provided inside the screw feeder 42 is rotated by a driving mechanism (not shown), and is supplied to the inside of the rotary drum 10. . The object to be processed W supplied from the supply port 41 comes into contact with the heating tubes 11, 11, ... heated by steam, is dried on one side, moves toward the other end side of the rotary cylinder 10, and is processed from the cover 35 as the object E through the discharge port 50 While drained.

On the other hand, the carrier gas A blown from the supply port 34 (the example in FIG. 1) or the supply port 41 (the example in FIG. 2) by a blowing mechanism provided on one end side of the rotating cylinder 10 passes through the inside of the rotating cylinder 10. And is discharged to the outside of the rotating cylinder 10 from the discharge port 50 which is also located at the discharge port of the object to be processed W.

In addition, the steam supplied from the steam supply pipe 70 into the heating pipe 11 is heat-exchanged by contacting the object to be processed W with the heating pipe 11 and is cooled during the circulation in the heating pipe 11 to become a condensate d. And discharged from the drain pipe 71.

(Modification)

Next, referring to FIG. 5 and FIG. 6, the operation when a horizontal rotary dryer including a stirring mechanism 65 and a classification cover 55 is used will be described. In this case, the part overlapping with the above description is omitted.

When the processed object W supplied into the rotating drum 10 reaches the position where the stirring mechanism 65 exists, the stirring mechanism 65 performs stirring, and then, as shown in FIG. 6, it is rotated and rotated as the rotating drum 10 rotates. The material plate 60 is raised. The lifted object W is located when the lifting plate 60 is located When the upper side of the rotating cylinder 10 is dropped, the fine particles C contained in the object to be processed W are dispersed in the rotating cylinder 10 (so-called flight action).

On the other hand, the carrier gas A blown from the supply port 41 by a blowing mechanism provided on one end side of the rotary cylinder 10 passes through the rotary cylinder 10 and from a discharge port 50 also located at a discharge port of the object to be processed W It is discharged out of the rotating cylinder 10. At this time, the carrier gas A is discharged from the discharge port 50 along with the fine particles C dispersed in the rotary cylinder 10 by the lifting plate 60. The carrier gas A discharged from the discharge port 50 is discharged from the classification cover 55 through the fixed exhaust port 56.

The particles with a larger particle size and a heavier weight in the to-be-processed object W fall into the rotating cylinder 10, and do not fall with the carrier gas A from the discharge port 50 located on the lower side. The naturally falling particles (to-be-processed object W) are discharged to the outside as the processed object E from the fixed discharge port 57.

(Variation of the supply method of the processed object)

A modified example of the object supply mechanism of the horizontal rotary dryer of the present invention will be described.

As a method for supplying the object to be processed to the horizontal rotary dryer, in addition to the above-mentioned spiral type (FIG. 3), a spray type (FIG. 7) or a vibration conveying trough type (FIG. 8) may be used. The jet type has a structure in which the supply chute 46 and the suction box 45 are coupled, and the object to be processed W supplied from the supply port 41 is dropped into the supply chute 46 and moved into the rotary cylinder 10. The suction box 45 is connected to the rotary cylinder 10 via a sealing gasket 47, and while maintaining the tightness between the rotary cylinder 10 and the suction box 45, the rotary cylinder 10 is rotated. The vibration conveying trough type suction box 45 is a conveying trough (the shape of the cross section is concave), and a vibration motor 48 and a spring 49 are combined at the lower end of the suction box 45. The to-be-processed object W supplied from the supply port 41 falls on a conveying tank. In addition, the suction box 45 is vibrated by the vibration motor 48 to move the object to be processed W into the rotating tube 10. When the suction box 45 is installed, in order to facilitate the movement of the object to be processed W, the suction box 45 should be inclined downward toward the rotating cylinder 10.

(Variation of rotary tube)

In addition to the circular shape described later, the cross-sectional shape of the rotating tube 10 may be rectangular (hexagonal, etc.) when necessary. If the rectangular rotating tube 10 is rotated, the rotating tube 10 is Since the processed object W is lifted up, there is an advantage that the miscibility of the processed object W becomes good. On the other hand, compared with the case of a circular shape, since the cross-sectional area of the rotating tube 10 is narrow, there is also a disadvantage that the number of the heating tubes to be arranged is reduced.

(Variation of discharge method of processed material)

As a method for discharging the processed object E from the horizontal rotary dryer, a form as shown in FIG. 9 may be adopted. In this embodiment, the carrier gas A is discharged from the inside of the rotary cylinder 10 through the inside of the partition wall 23 and through the casing 80 through the carrier gas discharge port 33 at the upper portion thereof. When the carrier gas A is a reuse gas, although the carrier gas A contains dust, etc., because the belt conveyor screw Z is arranged inside the partition wall 23, that is, the gas passage U2, dust and the like mixed in the gas Captured by the belt conveyor screw Z. The captured dust and the like are discharged to the openings 21 and 22 by the discharge action of the belt conveyor screw Z, and are discharged into the housing 80. The discharged dust and the like are discharged from the discharge port 32 below the casing because they fall freely.

Further, as the rotary cylinder 10 rotates, the spiral blade 24 also rotates. Therefore, the processed object E obtained by drying the processed object W is discharged to the openings 21 and 22 by the discharge action of the spiral blades 24 in the discharge path U1 and discharged from the openings 21 and 22. The discharged processed material E is discharged from the discharge port 32 below the housing due to its own weight.

On the other hand, a steam path (internal steam supply pipe 61 and internal drain pipe 62) extending through the housing 80 and extending into the partition wall 23 is integrated with the rotary cylinder 10. The internal steam supply pipe 61 is connected to the inlet head of the heating pipe 11 of the end plate portion 17, and the internal liquid discharge pipe 62 is connected to the outlet head of the heating pipe 11 of the end plate portion 17. The steam supply pipe 70 and the liquid discharge pipe 71 are connected to the internal steam supply pipe 61 and the internal liquid discharge pipe 62 via a rotary joint 63, respectively.

(Variation of Rotary Tube Support Structure)

In addition, the supporting structure of the rotating cylinder 10 may be provided on the spiral feeder 42 provided on one end side and the other end in addition to the above-mentioned supporting structure in which two hoop members 20 and 20 are mounted on the periphery of the rotating cylinder 10. On the outer periphery of the gas tube 72 on the side, a bearing (not shown) is installed to support the structure of the bearing; or a supporting structure in which the hoop member 20 and the bearing are used in combination.

The number of the heating tubes 11 and the configuration of the heating tubes 11 can be appropriately selected. For example, in addition to the arrangement along the radial line as shown in FIG. 10, it may also be a curve as shown in FIG.

<Conditions of the present invention>

In addition, as described above, the present invention must satisfy all the following conditions.

(1) The inert carrier gas is circulated in the rotating cylinder from the one end side to the other end side in a co-current manner; (2) the product temperature of the discharged dry matter is set to 95 ° C or higher; (3) the carrier gas is The temperature on the discharge side is 95 ° C or higher; (4) A heating mechanism for the carrier gas is provided on the other end side.

Here, the condition (1) can be satisfied in the form described above.

On the other hand, for the conditions of (2) setting the product temperature to 95 ° C or higher and (3) setting the temperature of the exhaust side of the carrier gas to 95 ° C or higher, the temperature of the heating medium flowing in the heating pipe is specified. In addition, the rotation speed and the configuration of the heating tube are also selected.

However, the important elements for satisfying the conditions (2) and (3) are the temperature of the carrier gas and the amount of air passing through the carrier gas in the rotating cylinder.

However, since these elements alone are not sufficient in most cases, a heating mechanism for a carrier gas is provided.

As an example thereof, as shown in FIG. 13, it is desirable to provide a jacket 12 surrounding the rotary tube 10 so as to circulate the heating medium S between the outer wall surface of the rotary tube 10 and the inner wall of the jacket 12. Heating is also performed from the outside of the rotating cylinder 10.

As a result, compared with the case where the jacket 12 is not provided, in addition to increasing the drying speed of the object to be processed W, it is also suitable for increasing the temperature of the carrier gas A at the other end side (discharge side) to prevent condensation.

Examples of the heating medium S include steam at 95 ° C. or higher (preferably 99 ° C. or higher) to 200 ° C., or exhaust gas from a factory (especially an iron plant).

In addition, instead of the jacket 12 described above, as shown in FIG. 14, the rotary cylinder 10 is surrounded. It is also ideal to set a plurality of companion pipes 12A.

Here, the temperature passing through the discharge port may be defined as "the temperature of the discharged dry product", but usually the outlet temperature of the cover 35 may be used as an index.

On the other hand, as the "temperature on the discharge side of the carrier gas", the outlet temperature of the discharge port is actually used as an index.

Further, as shown in FIG. 15, a fin 12B is provided on the discharge side of the heating pipe 11 to make it effectively improve the contact rate between the carrier gas and the object to be treated, and effectively improve the product temperature of the dry matter and the carrier gas Temperature heating mechanism.

On the other hand, in order to adjust the retention on the discharge side and reduce the filling rate, a holder 13 may be provided as shown in FIG. 16. The height of the holder 13 may be selected as appropriate.

By providing the holder 13, since the stagnation is performed less frequently than the downstream side, the filling rate of the "dried dry matter" can be reduced, and the product temperature of the discharged dry matter and the temperature of the discharge side of the carrier gas can be increased.

In addition, if the graph of drying change when looking at a certain kind of coal is shown in FIG. 12, the dew point of the gas is different when the amount of the carrier gas is large and when the amount of the carrier gas is small. In addition, if the product temperature is lower than the dew point of the gas, condensation will occur in the "condensation area" shown in the figure. Therefore, it is presumed that if the carrier gas temperature and product temperature are increased as shown in the figure, dew condensation can be prevented.

(Comparative example)

In the case of a certain kind of coal, as shown in Fig. 12, in the constant rate ~ reduction rate region, the product temperature is about 80 ° C ~ 90 ° C, and the gas temperature and gas dew point are also operated in the same temperature range. For example, when supplying 100wetT / h and drying the water from 10wt% to 5wt% in a co-current manner, the amount of exhaust gas required to prevent condensation is about 250m ³ / min. In the exhaust treatment, dust is collected. The filtering area of the machine must be about 250m ² and the exhaust fan must be about 45kW.

(Example)

In contrast, it is known that under the conditions of the present invention, the amount of carrier gas is About 20% is enough.

In addition, in consideration of the danger of dust explosion or fire, the dried product is thermoformed in most cases. In this case, although it is necessary to raise the product temperature to about 100 ° C. to 150 ° C., in the embodiment, the product temperature of the dried product has been increased, so it is also found to be suitable for thermoforming.

Claims (7)

A drying method using a horizontal rotary dryer, characterized in that the horizontal rotary dryer is provided with a supply port having a to-be-processed object on one end side, a discharge port having a to-be-processed object on the other end side, and a A rotating cylinder with a freely rotatable axis, and a plurality of heating pipes for heating medium to pass through the rotating cylinder are provided. During the process of supplying the object to one end side of the rotating cylinder and discharging from the other end side, The heating tube heats the object to be dried; the drying method using a horizontal rotary dryer satisfies all of the following conditions: (1) the inert carrier gas is moved from the one end side to the other end side in the rotating drum; and (2) The carrier gas is heated on the other end side of the rotary cylinder. A drying method using a horizontal rotary dryer, characterized in that the horizontal rotary dryer is provided with a supply port having a to-be-processed object on one end side, a discharge port having a to-be-processed object on the other end side, and a A rotating cylinder with a freely rotatable axis, and a plurality of heating pipes for heating medium to pass through the rotating cylinder are provided. During the process of supplying the object to one end side of the rotating cylinder and discharging from the other end side, The heating tube heats the object to be dried; the drying method using a horizontal rotary dryer satisfies all of the following conditions: (1) The inert carrier gas is moved from the one end side to the other end side in the rotating cylinder. Co-current circulation; (2) Set the product temperature of the discharged dry product to 95 ° C or higher; (3) Set the temperature of the discharge side of the carrier gas to 95 ° C or higher; (4) On the other end side of the rotating cylinder, The carrier gas is heated. A drying system using a horizontal rotary dryer is characterized in that the horizontal rotary dryer is provided with a supply port having a processing object at one end side, a discharge port having a processing object at the other end side, and a A rotating cylinder with a freely rotatable axis is provided with a plurality of heating tubes in the above rotating cylinder through which the heating medium passes. During the process of supplying the object to one end of the rotating cylinder and discharging from the other end, the heating is performed by the above heating. The tube heats the object to be dried; the drying system using the horizontal rotary dryer includes: (1) a flow of an inert carrier gas from the one end side to the other end side in a parallel flow in the rotating cylinder; A mechanism; and (2) a heating mechanism for heating the carrier gas provided on the other end side of the rotary cylinder. For example, the drying system using a horizontal rotary dryer according to claim 3, wherein the heating mechanism is a heating tube provided on the rotary drum. For example, the drying system using a horizontal rotary dryer according to claim 3, wherein the heating mechanism is a jacket structure provided on the other end side of the rotating cylinder to circulate the heating medium. For example, the drying system using a horizontal rotary dryer according to claim 3, wherein the heating mechanism is a fin provided on the other end side of the heating tube. For example, the drying system using a horizontal rotary dryer according to claim 3, wherein a holder is provided inside the other end side of the rotary drum.