JP2633470B2 - Dry silo - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying silo in which hot air is passed from below to stored granules for drying.

[0002]

2. Description of the Related Art Generally, when plastics are molded with highly water-absorbing resins such as nylon and polycarbonate and polyester chips used as a raw material for PET bottles for carbonated beverages, heat is applied during molding. There has been a problem that hydrolysis by moisture occurs or a foaming phenomenon occurs by vaporization. Therefore, in order to solve these problems, a drying treatment is indispensable for the above-mentioned resin and the like. As the drying treatment, for example, heat treatment for several hours is performed before injection molding, or heat treatment is performed immediately after production of pellets or chips and during storage in a silo.

FIGS. 20 and 21 are schematic partial cross-sectional views each showing a conventional drying silo. In both drying silos, the air blown from the blower 2 is heated by the heater 3 and blown into the container 1 as hot air. In the drying silo of FIG. 20, the hot air blown into the container 1 is
The air is blown out from a large number of holes 4a of a perforated plate 4 made of a punching plate, a sintered wire mesh or the like, and flows from below in the container 1. In the drying silo shown in FIG. 21, the hot air blown into the container 1 is blown into the inner space of the baffle 7 through the air duct 6, and the hot air blows out from the many holes 17 a of the perforated plate 17 constituting the lower part of the baffle 7. It is blown out and flows from below in the container 1.

However, in the dry silo shown in FIG.
There were the following problems. That is, in order to perform sufficient drying treatment on the granules 5, it is necessary to increase the amount of hot air to be blown. The hot air blown out from the perforated plate 4 becomes non-uniform, and the granules 5 are uniform. It is difficult and expensive to perform a proper drying process.

In the drying silo shown in FIG. 21, a thick air duct 6 is provided to be inserted from the side, so that when the granules 5 are discharged after the drying process, the air duct 6 prevents the discharge by mass flow. And the flow of the discharged granules 5 was uneven. When such a drift occurs in discharging the granules 5, a part of the granules 5 stays in the container 1, and the staying granules 5 may remain for a long time and deteriorate in continuous operation. . That is, in the drying silo of FIG. 21, as a result, the drying process for the granules 5 was not uniform.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a uniform drying process by uniformly flowing hot air to stored granules, and to prevent the occurrence of drift when discharging the granules. It is an object of the present invention to provide a dry silo which can be discharged by mass flow.

[0007]

The drying silo of the present invention comprises:
A drying silo is provided with an upright cylindrical container having an inlet at an upper portion and an outlet at a lower portion, and a hot air is supplied from below to dry the granules stored in the container to drop the stored granules by mass flow. Baffle is provided at a lower portion in the container, and the baffle is inclined downward from the center of the container toward the peripheral wall of the container and has a substantially conical shape provided such that a radially outer peripheral edge is equidistant from the peripheral wall. A blow pipe for blowing hot air is provided vertically below the baffle until the lower end reaches the discharge port, and is provided so as to have an equal interval with the peripheral wall. It is located in the inner space of the baffle, and a number of air outlets are provided in the middle of the baffle in the vertical direction, and the lower part of the baffle is closed so that air is squeezed from the inner space of the baffle and blown out. Features.

[0008]

In the drying operation, hot air is introduced into the baffle through the blow pipe, is blown out from the upper and lower parts of the baffle, rises in the container, and becomes a rising airflow that spreads uniformly above the baffle. Therefore, the stored powder is uniformly dried.

In the discharging operation, the particles tend to flow in the mass flow because of the baffle. However, the particles flow down in the mass flow favorably because they do not hinder the vertical arrangement of the blowing pipe.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments.

(Embodiment 1) FIG. 1 is a partial cross-sectional schematic overall view of a dry silo of this embodiment. 1 is an upright cylindrical container in which granules 5 are stored, 2 is a blower for supplying air into the container 1, 3 is a heater for heating air supplied from the blower 2 to generate hot air, and 6 is a heater for blowing air from the blower 2. An air duct (blowing pipe) 7 for introducing air supplied through the heater 3 into the container 1 is a baffle. Reference numeral 200 denotes a charging / transporting line for charging the granules 5 sent from the previous process into the container 1, and reference numeral 210 denotes a granule 5 discharged from the outlet 1 a of the container 1 via the rotary valve 211 in the next step. A transport device 230 for sending the product 5 to the shipping transport line 220 is a circulating transport line that returns the particles 5 passing through the shipping transport line 220 into the container 1. The transport device 210 includes a suction air filter 212, a pneumatic transport blower 213, and a line air filter 214. A two-way switching valve 221 is provided in the middle of the shipping transport line 220, and the shipping transport line 220 and the circulating transport line 230 are switched by the two-way switching valve 221. A bag filter 241 is interposed in the air recovery line 240.

FIG. 2 is an enlarged sectional view of the lower portion of the container 1.
The lower peripheral wall 11 of the container 1 is inclined toward the discharge port 1a located at the center O (FIG. 1) of the container 1 and at the lower end. That is, the lower part of the container 1 gradually narrows and communicates with the discharge port 1a. Further, the inclination of the peripheral wall 11 is of two stages, and the inclination angle α of the lower stage 11 a is
The angle of repose is set to be larger than that shown in FIG.
The inclination angle β of b is set to be larger than α. For example, α is set to 60 degrees and β is set to 66 degrees.

The baffle 7 is for discharging the granules stored in the container 1 by mass flow. FIG. 3 is a perspective view of the baffle 7. Baffle 7
1 and a lower part 72, the upper part 71 is a hollow, substantially conical shape opened downward, and the lower part 72 is a substantially cup-shaped one closing the upper part 71 from below. A large number of circular air outlets 71a are formed on the same horizontal plane in the vertical direction of the upper portion 71, and a circumferentially continuous eave 71b is provided immediately above the air outlet 71a. The eaves 71b are inclined downward.

The baffle 7 has a top 71c located at the center O of the container 1 and a support plate 7
3 is supported. For example, three support plates 73 are provided at equal intervals in the circumferential direction and in the vertical direction.

The air duct 6 has a smaller pipe diameter than the discharge port 1a, and stands upright below the baffle 7.
The vertical main body 61 of the air duct 6 is located at the center O of the container 1, the upper end opening 61a is located in the inner space of the baffle 7,
The lower end 61b is located in the outlet 1a. Lower end 6
A hot air inlet pipe 62 that penetrates through the outlet 1a and communicates with the blower 2 communicates horizontally from both sides with 1b. Between the upper end 61c of the vertical main body 61 and the lower part 72 of the baffle 7, a gap 72a continuous in the circumferential direction is provided.
At the lower end of the vertical main body 61, an opening 61d is formed.

On the upper surface of the hot air inlet pipe 62, an inclined plate 63 for preventing the stagnation of the granules 5 is provided. Of FIG.
As shown in FIG. 4 which is an IV-IV sectional view and FIG. 5 which is a VV sectional view of FIG. 2, the inclined plate 63 is constituted by two plates 63a, and the plate 63a is a hot air inlet pipe. It inclines so that it may become tangent to the surface of the hot air inlet pipe 62 from the vertex 63b located on the vertical center line of 62.

In the drying silo having the above structure, the blower 2
The hot air supplied from the heater 3 through the heater 3 is introduced into the inner space of the baffle 7 by the air duct 6, and as shown by the arrow in FIG.
a, the air is blown out of the baffle 7, rises, and becomes an ascending airflow uniformly spread above the baffle 7. The overall size of the baffle 7, the position, size, number, etc. of the outlets 71a, and the position, size, etc., of the gap 72a are appropriately set so that the above-described evenly widened updraft is obtained. Therefore, according to the drying silo having the above configuration, the granules 5 stored in the container 1 are uniformly dried.

On the other hand, the granules 5 are operated as follows. At the start of the drying process, the discharge temperature of the granules 5 is lower than the desired set value and the granules 5 are in an undried state. Therefore, the discharge temperature of the granules 5 first becomes the desired set value, and the drying process state is stabilized. Circulating using the circulating transport line 230. That is, the granular material 5 is discharged through the rotary valve 211 while being charged into the container 1 from the charging and transporting line 200, and is returned into the container 1 through the circulating transport line 230 by the transporting device 210. Then, when the drying processing state is stabilized and the storage amount of the granules 5 in the container 1 increases, the two-way switching valve 221 is switched, and the circulating transport line 230 is closed. As a result, the granules 5 fed from the charging / transporting line 200 are continuously sent to the shipping / transporting line 220 after being in a stable drying state in the container 1.

The granules 5 are discharged as follows. That is, the granules 5 tend to flow in a mass flow because of the baffle 7, but the vertical main body 61 of the air duct 6 stands upright below the baffle 7, and the lower end 61 b is located in the discharge port 1 a. As a result, the gas flows satisfactorily in the mass flow without being hindered by the air duct 6. Furthermore, since the inclined plate 63 is provided on the upper surface of the hot air inlet pipe 62, the hot air inlet pipe 62
Is hardly hindered, and the granules 5 are
2 does not remain. Therefore, the granules 5 are completely discharged from the container 1 through the discharge port 1a.

Moreover, since the inclination angle α of the lower stage 11a of the peripheral wall 11 is set larger than the angle of repose and the inclination angle β of the upper stage 11b is set larger than α, the granular material 5 remains on the inner surface of the peripheral wall 11. No, it is definitely discharged. Generally, the granules 5 tend to stay from the straight body portion 12 of the container 1 to the vicinity of the upper part of the peripheral wall 11, but since β is set to be larger than α, the granules 5 in that portion are likely to stay.
Is not particularly slowed down, and the granules 5 surely flow in a mass flow. Incidentally, when α is smaller than the angle of repose, the granules 5 remain on the inner surface of the lower stage 11a. Also, if all of the peripheral wall 11 is α, the flow of the granules 5 near the inner surface of the peripheral wall 11 is slightly slowed, which may hinder mass flow. If β, the vertical dimension of the peripheral wall 11 increases, and the overall size of the container 1 increases, resulting in inconvenience in terms of cost, production, installation, and the like.

Further, during the drying operation, the granules 5
However, there is a possibility that the particles 5 entering the baffle 7 from the outlet 71a and further into the vertical body 61 may flow out of the gap 72a and enter the baffle 7 into the baffle 7. Flows out from the opening 61d, so that the granules 5 are completely discharged from the container 1 from this point as well.

(Embodiment 2) FIG. 7 is an enlarged sectional view of the lower part of the container of the drying silo of this embodiment. This dry silo is
Only the configuration of the baffle 7 is different from the first embodiment. FIG.
Is a perspective view of the baffle 7 of the present embodiment. In the baffle 7, the outlet 71a is formed in a slit shape.
Here, they are provided in two rows. FIG. 9 is an enlarged view of a portion A in FIG. 7, and shows a portion where the outlet 71a is formed. Also, the lower portion 72 has a cylindrical wall portion 72b,
A large number of slit-shaped outlets 72c are provided in the wall 72b.
Are formed in rows. Each row is located on the same horizontal plane. The lower edge of the upper portion 71 serves as an eave 71d for the outlet 72c. FIG. 10 is an enlarged view of a portion B in FIG. 7, and shows a portion where the outlet 72c is formed.
There is almost no gap between the upper end 61c of the vertical main body 61 and the lower part 72 of the baffle 7. Other configurations are the same as those of the first embodiment, and the same reference numerals as those of the first embodiment denote the same or corresponding components.

In the drying silo having the above structure, the hot air is
Introduced into the inner space of the baffle 7 by the air duct 6,
As shown by an arrow in FIG.
a, is blown out of the baffle 7 through the 72c, rises,
The upward airflow spreads uniformly above the baffle 7.
The overall dimensions of the baffle 7 and the positions, dimensions, numbers, etc. of the outlets 71a and 72c are appropriately set so as to obtain the above-described evenly expanded airflow. Therefore, according to the drying silo having the above configuration, the granules 5 stored in the container 1 are uniformly dried.

The discharge of the granules 5 is performed as follows, as in the first embodiment. That is, the granules 5 tend to flow by the mass flow because of the baffle 7, but do not hinder by the air duct 6, so that they flow well by the mass flow. Other functions and effects are the same as those of the first embodiment.

(Embodiment 3) FIG. 12 is an enlarged sectional view of the lower part of the container of the drying silo of this embodiment. This drying silo is composed of a baffle 7 and a vertical main body 6 of an air duct 6.
Only the configuration 1 is different from the first embodiment. In the baffle 7, the upper portion 71 has a substantially conical shape and is formed in two steps vertically, the outlet 71 a is formed at the upper end of the lower portion 171, and the eaves 71 b are located below the upper portion 172. It is constituted by an edge. A large number of outlets 61e are formed in the vertical direction of the vertical main body 61 of the air duct 6 so as to be located on the same horizontal plane.
Immediately above 1e, a circumferentially continuous eave 61f is provided. The eaves 61f are inclined downward. Other configurations are the same as those of the first embodiment, and the same reference numerals as those of the first embodiment denote the same or corresponding components.

In the drying silo having the above structure, the hot air is
Introduced into the inner space of the baffle 7 by the air duct 6,
As shown by arrows in FIG.
2a, and further, the air is blown out of the baffle 7 and the vertical main body 61 through the air outlet 61e, rises, and becomes an ascending airflow uniformly spread above the baffle 7. In the present embodiment, since the hot air is also blown from the outlet 61e of the air duct 6, the hot air can be blown from a wide range in the vertical direction.
The above-mentioned evenly widened updraft is likely to occur. In addition,
Dimensions of the entire baffle 7, positions of the outlets 71a, 61e,
The size, the number, etc., and the position, the size, etc. of the gap 72a are appropriately set so as to obtain the above-described evenly expanded updraft. Therefore, according to the drying silo having the above configuration, the granules 5 stored in the container 1 are uniformly dried.

The discharge of the granules 5 is also as follows, as in the first embodiment. That is, the granules 5 tend to flow by the mass flow because of the baffle 7, but do not hinder by the air duct 6, so that they flow well by the mass flow. Other functions and effects are the same as those of the first embodiment.

(Embodiment 4) FIG. 15 is an enlarged sectional view of the lower part of the container of the drying silo of this embodiment. The drying silo has an air duct 6 and an outlet 1 of the container 1.
Only the configuration a is different from the first embodiment. The outlet 1a of the container 1 of the present embodiment includes a vertical portion 10a, an inclined portion 10b, and a vertical portion 10c, and the air duct 6 is provided such that a vertical main body 61 penetrates a wall of the inclined portion 10b. I have. An inclined plate 64 is provided on the side of the vertical main body 61 opposite to the inclined side of the inclined portion 10b. X in FIG.
As shown in FIGS. 16 and 17 which are VI-XVI sectional views,
The inclined plate 64 is composed of two plates 64a.
4a are inclined to opposite sides from the apex 64b located on the transverse center line O ₁ of the vertical body 61.

In the drying silo having the above structure, the hot air is
As in the case of the first embodiment, the air flows as shown in FIG. 6, and becomes an ascending airflow that spreads uniformly above the baffle 7. Therefore, according to the drying silo having the above configuration, the granules 5 stored in the container 1 are uniformly dried.

The granules 5 are discharged as follows. That is, the granules 5 tend to flow in a mass flow due to the baffle 7, but since the vertical main body 61 of the air duct 6 stands upright below the baffle 7, the granule 5 is not obstructed by the air duct 6, Flows well in mass flow. Moreover, since the inclined plate 64 is provided, the vertical main body 61 itself hardly hinders the flow due to the mass flow, and the granules 5 are connected to the vertical main body 61 and the inclined portion 1.
It does not remain at the intersection with 0b. Therefore, the dried granules 5 are completely discharged from the container 1 when the discharge port 1a is opened. Other functions and effects are described in Example 1.
Is the same as

(Embodiment 5) FIG. 18 is an enlarged sectional view of the lower part of the container of the drying silo of this embodiment. This drying silo differs from the first embodiment in that a baffle 7 is supported by an air duct 6. That is, in the present embodiment, the upper end 61 c of the vertical main body 61 of the air duct 6 is
Are fitted to the lower part 72 of the base member, and both are joined. In the baffle 7, a large number of outlets 71a, 71e, 72d are formed so as to be located on the same horizontal plane.
71 g is an eaves.

According to the drying silo having the above structure, the support plate 73 (FIG. 2) for the baffle 7 is not required, so that the flow of the granules 5 is not hindered by the support plate 73 during the discharging operation. Therefore, the discharge of the granules 5 by the mass flow is performed more favorably than in the case of the first embodiment. Other functions and effects are the same as those of the first embodiment.

(Embodiment 6) FIG. 19 is an enlarged sectional view of the lower part of the container of the drying silo of this embodiment. The container 1 of this dry silo has a large diameter with a body diameter L of 4 m or more, and an auxiliary blowing port 77 is formed at a lower portion of the straight body portion 12 of the container 1. 77a is an eave.

When the container 1 has a large diameter, the baffle 7 is used in order to obtain an ascending airflow spread evenly above the baffle 7.
Also need to be enlarged. Unless the size of the baffle 7 is increased, there is a possibility that an evenly widened updraft cannot be obtained on the wall surface of the container 1. However, increasing the size of the baffle 7 is uneconomical. However, in the drying silo having the above configuration, since the auxiliary blowing port 77 is provided, the container 1
The flow of the air current on the wall surface of the air conditioner becomes good. Therefore, even if the size of the baffle 7 is not increased, an ascending airflow uniformly spread above the baffle 7 including the wall surface of the container 1 can be obtained.

[0035]

As described above, according to the present invention, the following effects can be obtained. (1) According to the drying silo of the first aspect, in the drying operation, hot air is blown out from the upper part (for example, the outlet 71a) and the lower part (for example, the gap 72a) of the baffle 7 so as to be above the baffle 7. As a result, the ascending airflow can be evenly spread. Therefore, the stored powder 5 can be uniformly dried.

In the discharging operation, the air duct 6
The granules 5 can be satisfactorily flowed in a mass flow without being hindered by the (blowing pipe), that is, without causing drift. Therefore, as a result, the granules 5 can be uniformly dried.

(2) According to the drying silo of the second aspect, the inclination angle α of the lower stage 11a of the peripheral wall 11 is set larger than the angle of repose, and the inclination angle β of the upper stage 11b is set larger than α. Therefore, the particles 5 can be reliably discharged without leaving the particles 5 on the inner surface of the peripheral wall 11. Moreover, since β is set to be larger than α, the flow of the granules 5 in the portion from the straight body portion 12 of the container 1 to the vicinity of the upper portion of the peripheral wall 11 can be prevented from being delayed, and the granules 5 can be reliably formed. It can be flowed by mass flow. In addition, assuming that all of the peripheral wall 11 is β, the vertical dimension of the peripheral wall 11 becomes large, the dimension of the entire container 1 becomes large, and disadvantages occur in terms of cost, production, installation, and the like. Such inconvenience can be prevented.

(3) According to the drying silo of the third aspect, the hot air can be blown out not only from the baffle 7 but also from the middle of the air duct 6, so that it spreads evenly above the baffle 7. A raised airflow can be easily generated.

(4) According to the drying silo of the fourth aspect, the granular material 5 that has entered the vertical main body 61 of the air duct 6 can flow out of the opening 61d. Can be completely discharged from the container 1.

(5) According to the drying silo of the fifth aspect, the support plate 73 for supporting the baffle 7 can be made unnecessary, so that the granules are not hindered by the support plate 73, that is, without causing drift. 5 can be satisfactorily caused to flow by mass flow.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional view of a dry silo according to a first embodiment.

FIG. 2 is an enlarged sectional view of a lower portion of the container of the first embodiment.

FIG. 3 is a perspective view of a baffle according to the first embodiment.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 2;

FIG. 6 is a cross-sectional view illustrating a flow of hot air in the first embodiment.

FIG. 7 is an enlarged sectional view of a lower portion of the container of the second embodiment.

FIG. 8 is a perspective view of a baffle according to a second embodiment.

FIG. 9 is an enlarged view of a portion A in FIG. 7;

FIG. 10 is an enlarged view of a portion B in FIG. 7;

FIG. 11 is a cross-sectional view illustrating a flow of hot air according to the second embodiment.

FIG. 12 is an enlarged sectional view of a lower portion of the container of the third embodiment.

FIG. 13 is a perspective view of a baffle according to a third embodiment.

FIG. 14 is a cross-sectional view illustrating a flow of hot air in the third embodiment.

FIG. 15 is an enlarged sectional view of a lower portion of the container of the fourth embodiment.

16 is a sectional view taken along the line XVI-XVI in FIG.

FIG. 17 is a partial cross-sectional view of a discharge port of the container of the fourth embodiment.

FIG. 18 is an enlarged sectional view of a lower portion of the container of the fifth embodiment.

FIG. 19 is an enlarged sectional view of a lower portion of the container of the sixth embodiment.

FIG. 20 is a partial cross-sectional schematic overall view showing an example of a conventional drying silo.

FIG. 21 is a partial cross-sectional schematic overall view showing another example of a conventional drying silo.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 1a Discharge port 5 Granule 6 Air duct (blow-in pipe) 7 Baffle 11 Peripheral wall 11a Lower (of peripheral wall) 11b Upper (of peripheral wall) 61a Opening 61d Opening (particle outlet) 61e, 71a (Air) outlet

Claims (5)

(57) [Claims] 1. A drying silo, comprising: an upright cylindrical container having an inlet at an upper portion and an outlet at a lower portion, wherein a drying process is performed by flowing hot air from below onto the granules stored in the container. A baffle is provided in the lower portion of the container for dropping the container by mass flow, and the baffle is provided so as to be inclined downward from the center of the container toward the peripheral wall of the container and have a radial outer peripheral edge having an equal interval between the peripheral wall and the peripheral wall. A blowpipe for blowing hot air is provided vertically below the baffle until the lower end reaches the discharge port, and is provided at an equal interval with the peripheral wall. The opening at the tip of the pipe is located in the inner space of the baffle, and a number of air outlets are provided in the vertical direction of the baffle, and the lower part of the baffle is closed so that air is squeezed out of the inner space of the baffle and blown out. Specially Drying silos to be. 2. The container according to claim 1, wherein the lower peripheral wall of the container is inclined toward the discharge port, and the inclination angle has two steps, and the lower inclination angle is set to be larger than the angle of repose of the particles stored in the container. 2. The drying silo according to claim 1, wherein the inclination angle of the upper stage is set larger than the inclination angle of the lower stage. 3. The drying silo according to claim 1, wherein a number of air outlets are provided in a portion of the blow pipe below the baffle. 4. The drying silo according to claim 1, wherein a downwardly opened granular material outlet is provided at a lower end portion of the blowing pipe located in the container. 5. The dry silo according to claim 1, wherein the baffle is supported only by the blow tube.