JPH0791832A - Dryer - Google Patents

Abstract

PURPOSE:To prevent entangling of stringlike substance contained in a matter to be dried by increasing effects of removing adhered matter to an inner wall of a drum and lifting the matter to be dried in a drum dryer having rotary agitating blades. CONSTITUTION:A rotary shaft 2 of agitating blades 3 is disposed under a center of a drum 1 in such a manner that the blade 3 is formed in a wide plate state of a uniform section from its root to its end and has a slope retracting in a hot air flowing direction. The end of the blade 3 is approached to an inner wall of a dryer drum, and the blade 3 is rotated at number of revolutions faster, as a matter 4 to be dried is wound up more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary machine for drying, for example, general household waste (combustible waste) that partially melts during drying, or plastics, vinyl or the like that contains string-like substances. Regarding dryers.

[0002]

2. Description of the Related Art Generally, household waste (combustible waste) discharged from households is incinerated or reused as solid fuel. When it is reused as a solid fuel, it needs to be dried in the manufacturing process. 1-2 household waste
It is common to dry the crushed product with a base crusher.

For the drying of general household waste, a rotary dryer having a rotary drum and rotary stirring blades and drying with hot air is usually used, as in the case of drying sludge and the like. The conditions that such a dryer must have are as follows. (A) It has a function of scraping off the melt adhered to the inner wall of the drum. General household waste contains plastic and vinyl chloride, which melt when heated and dried. The melt adheres to the inner wall of the drum and solidifies and grows,
Since it hinders the operation of the dryer, it is necessary to scrape off the melt adhered to the inner wall of the drum. (B) The dried product is in sufficient contact with hot air and has a large heat transfer coefficient.

It is essential that the dried material, which tends to be deposited on the bottom of the rotating drum, be lifted to the upper part of the drum to be dropped and dispersed so that sufficient contact with hot air is possible. (C) Long string-like substances should not get caught in the equipment inside the dryer. Long strings are included in the dry matter, even though they say they crush household waste. If these get entangled with the equipment inside the dryer, it hinders the operation, and it is required to avoid this. (D) In the conventional dryer, since the dry matter inlet 17 is located above the hot air duct 9, the falling object is immediately exposed to hot air, easily catches fire, and stays at the position of the falling position 16. Since it was too dry and ignited easily, which caused a fire in the dryer oven, prevent it. (E) The hot air does not flow along the length of the drum, but fills the entire furnace.

[0005]

In the existing dryer, the stirring blade is provided so as to simultaneously satisfy the above conditions (a) and (b), but the stirring blade is satisfied although the condition (a) is satisfied. Since the arrangement position of the rotating shaft is not necessarily appropriate, the effect of lifting and dispersing the dried product is poor, and efficient heat transfer with hot air cannot be achieved. Further, in the existing shape of the stirring blade, since the string-like substance is entangled with the stirring blade, the operator enters the drum of the dryer about once a day and removes it.

[0006] The present invention is a dryer which is partially melted during drying and is used for drying a dried product containing a string-like substance, for example, general household waste containing plastic, vinyl chloride and the like. It is an object of the present invention to provide a dryer that solves the above problems.

[0007]

According to the present invention, in a rotary dryer having a rotating drum and a rotary stirring blade, the center of the rotating shaft of the stirring blade is located below the center of the rotating drum, and the stirring blade extends from the root to the tip. A wide plate with a uniform cross section, the tip of which is made to approach the bottom surface of the inner wall of the dryer drum through a slit, and is attached to the shaft by inclining in the direction along the flow of hot air,
Further, the present invention provides a rotary dryer characterized in that a speed difference is imparted to the rotational speed of the stirring blade and the rotational speed of the drum.

In addition, since this method ensures reliable stirring,
It is also possible to stop the rotation of the drum and make it a static drum,
This can reduce costs. It is preferable that the dry matter supply port is provided in the lower part of the drum and the hot air blowing port is provided in the tangential direction of the drum. It is possible to agitate the dry matter by the swirling flow and form a full flow of hot air over the entire surface of the furnace.

That is, according to the present invention, in a dryer for drying waste, household waste, sludge, etc., the center of the rotating shaft of the stirring blade is arranged below the center of the rotating drum. The stirring blade is attached to the shaft while being inclined in the axial direction (flow direction of hot air).
The stirring blade has a wide tip and a uniform cross section, and is composed of a wide flat plate without irregularities. When the drum is rotated by bringing its tip close to the inner wall of the dryer drum, the melt adhered to the inner wall of the drum is effective by providing a speed difference between the tip of the stirring blade and the inner wall of the drum (difference in rotation speed of the stirring blade with the drum). It will be scraped off.

[0010]

The dryer of the present invention has the following functions. (1) Since the center position of the rotating shaft of the stirrer is set below the center of the drum, the adhering substances in the drum are scraped off at the lowest end of the drum, and at the same time, the dried substance accumulated on the bottom of the drum is effectively lift.

(2) The stirring blade is a flat plate having a uniform cross section and no irregularities. Since the shape of the stirring blade has been optimized,
The string-like material does not wrap around, and it is easy to come off even if entangled. If the width of the flat plate is about 1/2 of the typical length of the string-like substance that is expected to be mixed in the dried product, the string will not wrap around the flat plate more than once, so entanglement prevention Is desirable.

(3) The stirring blade has a straight tip and is brought close to the bottom surface of the inner wall of the dryer drum through a slit. Since the center of the stirring blade is below the rotating drum, it is closest to the inner surface of the drum on the bottom surface of the inner wall of the drum. By disposing this portion through a slit, the dried material on the inner surface of the drum can be scraped off efficiently. When rotating the drum When rotating the drum By imparting a difference in the number of rotations of the drum and the stirring blade, it is possible to uniformly scrape off all the inner wall portions in the drum. The size of the narrow gap is set to, for example, about 4 to 10 mm in consideration of the deformation of the dryer drum and the minimum gap required for removing the wound one. Even with this amount of space, the deposits in the drum are scraped off by the accumulated dust, so scraping is possible.

(4) The agitating blade is attached to the shaft by inclining it in the leeward direction of the hot air and having an inclination to recede in the axial direction of the agitating blade. As a result, the string-like substance lifted from the bottom of the rotary drum is dropped into the space in which hot air flows without dropping along the stirring blade. Also, due to the flow of hot air,
The string-like substance is likely to come off, and the probability of entanglement with the stirring blade shaft is reduced.

(5) Since the rotating speed of the stirring blade is increased by providing a speed difference between the rotating speed of the stirring blade and the rotating speed of the drum, the melt adhered to the inner wall of the drum can be scraped off uniformly. If the direction of rotation is reversed, stirring and frying will be further promoted. (6) If the dry matter inlet is set at the lower part of the drum, hot air is introduced from the tangential direction of the drum, and swirling and stirring is performed with the hot air while allowing the hot air to pass through the entire surface of the furnace, heat exchange is also good.
Ignition is also unlikely to occur.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall view of a rotary dryer according to an embodiment, and FIG. 2 is a cross sectional view thereof. In the embodiment, a drum 1 having a diameter of 1.8 mφ and a length of 8.0 m is equipped with a stirring blade 3 having an outer diameter of 1.5 mφ. The stirring blade is a plate with a uniform cross section having a width of 300 mm and a thickness of 20 mm, and is 60 in the axial longitudinal direction at every 120 ° central angle.
It is attached at 0 mm pitch.

The dried material 4 charged into the hopper 5 is supplied into the drum 1 by the screw feeder 6. The drum 1 is generally driven to rotate about X at 10 to 20 rpm. Stirring blade 3 attached to stirring blade rotating shaft 2
In the same direction as drum 1 at a faster speed (30-50
rpm) to scrape off the melt adhering to the inner wall of the drum 1 and at the same time lift the dried product 4 deposited on the drum bottom to the upper part.

The center Y of the rotating shaft 2 of the stirring blade is located vertically below h (about 14.5 cm) of the center X of the drum 1.
The above operation can be performed most effectively. The dried product 4 that has been lifted drops and disperses at the upper part, and comes into contact with the hot air supplied from the duct 9 to be dried. The dried product 4 which has been dried is discharged by the screw feeder 8 through the outlet hopper 7.

FIG. 3 shows a conventional stirring blade, and FIG. 4 shows a non-wrapping stirring blade of the embodiment. In the conventional stirring blade shown in FIG. 3, the scraping plate 13 is arranged in the outer diameter portion and is attached by the spokes 14 at right angles to the shaft 2, so that the string-like substance 15 is entangled with the spokes 14 and the shaft 2 and comes off. It was difficult to get inside, so it was necessary to go inside and maintain it. 4 (a), 4 (b)
The stirring blade 3 shown in is a wide flat plate having no unevenness and an outer diameter of 11
Has a straight line shape, and the whole has an inclination in the axial direction 12 of the stirring blade (flow direction of hot air). 4A shows the stirring blade 3 having a linear inclination, and FIG. 4B shows the stirring blade 3 having a curved inclination. Each blade is left with its position shifted so as to scrape off the inner surface and the entire surface of the drum.

In such a stirring blade, the dried product scraped up is thrown into the air and has a great effect of coming into contact with hot air. Further, since the stirring blades 3 are inclined in the direction of the hot air flow, there is an advantage that the entangled string-like substance is easily removed by the hot air.

[0020]

EFFECTS OF THE INVENTION In the dryer of the present invention, the entanglement of the string-like material on the stirring blade and the stirring blade shaft is almost eliminated, and the melt in the drum is not adhered. It became necessary. The hot air evenly filled the inside of the furnace and could be dried efficiently.

[Brief description of drawings]

FIG. 1A is a vertical sectional view of a dryer according to an embodiment, and FIG.
FIG.

FIG. 2A is a longitudinal sectional view of a dryer according to another embodiment, and FIG.
It is a BB arrow line view.

FIG. 3 is a view taken along the line CC of FIG.

FIG. 4 is a side view showing the shape of a stirring blade of the dryer of the embodiment.

FIG. 5 is a vertical sectional view of a conventional dryer.

FIG. 6 is a side view showing the shape of a stirring blade of a conventional dryer.

[Explanation of symbols] 1 drum 2 stirring blade rotating shaft 3 stirring blade 4 dry matter 5 hopper 6 screw feeder 7 outlet hopper 8 screw feeder 9 hot air duct

Front page continuation (72) Inventor Akimune Sato 2-3 2-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Co., Ltd. Tokyo headquarters (72) Inventor Mitsunari Takimoto 6-1, Whalei Nitta, Kawagoe City, Saitama Prefecture Within Japan Recycle Management

Claims (3)

[Claims] 1. A drum dryer having a rotating drum and a rotating stirring blade, wherein the center of the rotating shaft of the stirring blade is located below the center of the rotating drum, and the stirring blade is a wide plate having a uniform cross section from the root to the tip. And its tip is made to approach the bottom surface of the inner wall of the dryer drum through a slit, and is attached to the shaft while being inclined in the direction along the flow of hot air, and there is a speed difference between the rotation speed of the stirring blade and the rotation speed of the drum. A dryer characterized by being imparted. 2. A dryer having a rotating drum equipped with a rotating stirring blade, wherein the center of the rotating shaft of the stirring blade is located below the center of the drum, and the stirring blade has a wide plate shape with a uniform cross section from the root to the tip. The dryer is characterized in that its tip is made to approach the bottom surface of the inner wall of the dryer drum through a slit and is attached to the shaft while being inclined in the direction along the flow of hot air. 3. The dryer according to claim 1, wherein the dried material supply port is provided in a lower portion of the drum, and the hot air blowing port is provided in a tangential direction of the drum.