JPH0524314Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vertical dryer, and in particular to a vertical dryer for drying powdered milk, pigments, etc. to obtain a fine powder as a product with a high moisture content as an undried product. Regarding machines.

[Prior Art] Conventionally, dryers used to dry undried materials with a high water content or slightly viscous content to obtain fine powder as a product include spray dryers and flash dryers. . In these dryers,
The undried liquid or microparticle suspension is atomized using a pressure nozzle or rotating disk, or dispersed using a screw feeder, etc., and then fed into the drying case.
A dried product is obtained by exchanging heat by flowing hot air countercurrently or cocurrently with the supply direction.

[Problems to be solved by the invention] The dryer described above has the following problems. In other words, especially when drying undried materials with a high moisture content or materials with poor thermal conductivity using a spray dryer, it takes a long time to dry, so it is necessary to allow a long residence time in the drying case. , it is necessary to make the drying case longer or larger.

Therefore, the present invention provides a dryer that eliminates such inconveniences.

[Means for solving the problem] A vertical dryer supplies undried materials from a supply port provided at the top of the drying case and sends hot air from a hot air inlet provided at the bottom of the drying case. A conveying device in which a perforated plate is attached to the bottom of the drying case to fill the drying case, a scraper is provided above the perforated plate to separate the packed material from the dried material, and an inlet is formed above the scraper. The structure is such that the filling near the scraper is conveyed to near the top of the drying case.

[Function] The undried material is supplied from the supply port provided at the top of the drying case, while the hot air is sent from the hot air inlet provided at the bottom of the drying case, exchanging heat with the undried material in a countercurrent flow. be done. The supplied undried material adheres to the surface of the packing packed in the drying case, forms a thin film, and exchanges heat with the hot air. The filling near the scraper is also transported to the upper part of the drying case by a transport device. That is, the filling circulates in the drying case from the top to the bottom and from the bottom to the top, and while descending from the top to the bottom, the undried substances adhering to the surface of the filling are heat exchanged with hot air and dried. Ru. When the filling material reaches the perforated plate, it comes into contact with a rotating scraper and is agitated, and the dried material adhering to the surface of the filling material is peeled off and falls through the perforated plate to obtain a product. . In addition, if it is not yet dried, it is carried to the upper part of the drying case by a conveying device while being attached to the filling, and is dried again through hot air.

(Example) This embodiment will be explained with reference to the drawings.

FIG. 1 is a sectional view schematically showing the dryer 1. FIG.
The drying case 2 is composed of a long cylindrical main body 4 made of metal or the like and a cone 6 attached to the lower part of the main body 4. An upper lid 3 is placed on the main body barrel 4, and a mounting base 9 is fixed approximately at the center of the upper lid 3 to which an undried material supply port 5 and a cylindrical rotating shaft 7 are attached, as will be described in detail later. Further, the upper lid 3 is provided with a discharge port 11 for hot air that has exchanged heat with the undried material, and is discharged to a bag filter (not shown) or the like, and dust of the dried material contained in the hot air is removed. A hot air supply port 13 for supplying hot air, which is a heat medium for drying undried materials, is provided on the side of the cone 6 attached to the lower part of the drying case 2. The hot air supply port 13 may be located above the perforated plate 15, which will be described later, or may be provided so that hot air can be supplied to the upper and lower parts.
Further, a rotary valve 8 is attached to the lower end of the cone 6 for discharging dried material.

At the bottom of the drying case 2, in this embodiment, at the joint between the main body 4 and the cone 6, a perforated plate 15 is attached, which has a hole diameter and aperture ratio that are appropriately determined depending on the properties of the undried material when it is dried. It is being

The main element of the transporter 23 is composed of a mantle tube 25 and a screw 27 provided therein. It is arranged at a position approximately 1/5 below the top of the main body trunk 4. still,
A filling inlet 26 is formed in the lower part of the mantle 25 .

The screw 27 is formed by attaching a flat plate bent spirally to the rotating shaft 7. It rotates via a sprocket 21 fixed to the part. Further, the main body shell 4 is filled with a filler 32 having a diameter larger than the diameter of the hole drilled in the perforated plate 15 on the perforated plate 15 almost up to the vicinity of the upper end of the mantle cylinder 25 .
Further, the lower end of the rotating shaft 7 has a slight gap between the lower end of the mantle 25 and the perforated plate 15, and the filling 32
A scraper 30 is attached to separate the dried matter adhering to the filling material 32 from the filling material 32. In this embodiment, the scraper 30 is directly connected to the stirring shaft 7 and therefore rotates at the same rotation speed, but the rotation speed can also be changed using a speed reducer or speed increaser. In addition,
The filling amount of the filling material 32 in the drying case 2, the material, shape, size, etc. of the filling material 32 are determined in consideration of the properties of the undried material.

Next, a method for supplying undried materials will be explained with reference to FIG. The supply port 5 is connected to a rotating shaft 7
It is connected to the swivel joint 34 via a so-called swivel joint 34. Since the moisture content of the undried material used in this example is 90% or more, it is supplied through the supply port 5 by rotary spraying. Therefore, a cavity 40 is formed in a part of the upper part of the rotating shaft 7, and discharge pipes 35, 35 are provided in communication with the cavity 40 and perpendicular to the rotating shaft 7. Spray nozzles 36, 36 for spraying the undried material are attached to the ends of the discharge pipe 35. Note that a blind flange 37 is attached to the rotating shaft 7 located at the lower part of the discharge pipe 35 to prevent undried materials from flowing down. Therefore, the undried material passes from the supply port 5 through the cavity 40 and the supply pipe 35, is sprayed from the spray nozzles 36, 36 which rotate in the same direction as the rotating shaft 7, and is uniformly dispersed within the drying case 2.
Note that the method for supplying the undried material is not limited to the method described above, as long as it can be uniformly distributed over the cross section of the drying case 2,
It goes without saying that fixed methods are also good.

Next, FIG. 3 shows the plane of the scraper 30,
The scraper 30 is made of a material such as thin metal, and has an S-shaped blade shape centered on the rotating shaft 7.
The number and shape of the scrapers, for example, the ends of the scrapers may be bent vertically, and various shapes can be determined depending on the properties of the undried material.

Next, the effect based on the above will be explained. The undried material is supplied from the supply port 5 and is uniformly sprayed into the drying case 2 (main body shell 4) from the sprayers 36, 36 which rotate at the same time as the rotating shaft 7, and the sprayed undried material is transported by the transporter 23. The filling material 32 that is circulating
adheres to the surface of That is, the filling 32 is carried to the upper part by the scraper 27 from near the scraper 30, discharged from the upper part of the mantle 25 to the outside of the mantle 25, and circulated within the main body shell 4, and the undried matter is removed from the filling. 3
It adheres to the surface of 2. In the process of moving down inside the main body shell 4, that is, in the direction of the perforated plate 15, the packing 32 with the undried matter attached thereto is heat exchanged with the hot air sent from the lower part of the perforated plate 15, and the undried matter is gradually removed. It descends onto the perforated plate 15 while being dried, and the drying is completed. The filling 32 to which already dried matter has adhered is
A rotating scraper 30 installed above the perforated plate 15 contacts and agitates the material, and due to the friction between the packings 32, the dried material is peeled off from the packings 32 and removed from the holes provided in the perforated plate 15. It falls into the cone 6 and is discharged via the rotary valve 8. On the other hand, the packing material 32 from which the dried material has been peeled off is carried by the transporter 23 to near the top of the drying case 2, and new undried material is attached thereto.

In addition, if it is not dried, it is carried to near the upper part of the drying case 2 via the transporter 23 while remaining attached to the filling material 32, and is dried again with hot air.

[Effect of the invention] According to the dryer of the invention, the undried material is dried by heat exchange with hot air while forming a thin film on the surface of the filling material. Therefore, the area where the undried materials come into contact with the hot air increases, and since they adhere evenly to the filling,
Uniform drying is possible and the drying case can be made smaller. This dryer is particularly effective for undried materials with poor thermal conductivity or high moisture content.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing a dryer according to an embodiment of the present invention, Fig. 2 is a diagram showing a method of supplying undried materials, and Fig. 3 is a schematic sectional view showing a dryer according to an embodiment of the present invention.
The figure is a plan view of the scraper. 1... Dryer, 2... Drying case, 4... Main body, 5... Supply port, 6... Cone, 7... Rotating shaft, 13... Hot air supply port, 15... Perforated plate, 23
...Transporter, 30...Scraper, 32...Filling material.

Claims (1)

[Scope of utility model registration request] In a vertical dryer, undried materials are supplied from a supply port provided at the top of a drying case, and hot air is sent from a hot air inlet provided at a bottom of the drying case. A scraper is installed above the perforated plate to fill the filling material onto the plate, agitate the filling material, and peel off and separate the dried material adhering to the filling material. A vertical dryer characterized by installing a conveying device that conveys the nearby filling near the top of the drying case.