JPH0113031B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a rotary kiln for drying a workpiece such as a wet granulated material such as ore and then firing it.

[Conventional technology]

A rotary kiln that is commonly used is intended only for firing (roasting) the object to be processed. Therefore, normally, the workpiece has been dried using a band dryer, a grate type preheater, etc., and then put into a rotary kiln.

In addition, for drying or firing granular materials such as iron ore, a rotary kiln with a heat exchange chamber consisting of a collection of radial chambers, that is, a drying chamber, was developed in the 1970s.
This is proposed by Publication No. -37323.

This rotary kiln is equipped with a heat exchange chamber, that is, a drying chamber, which is made up of a collection of radial chambers formed by a slope bottom plate that is inclined in the axial direction toward the rear of the kiln, and a partition plate. The material is distributed into radial chambers within the exchange chamber, exchanges heat with the combustion gas as it is transferred from the partition plate to the sloping bottom plate, and then drops to the bottom of the kiln to dry the material. It is designed to be fired by sending it forward.

[Problem that the invention seeks to solve]

The conventional rotary kiln commonly used as described above requires drying equipment separate from the kiln, resulting in an increase in equipment costs.

In addition, in the rotary kiln described in the above-mentioned Japanese Patent Publication No. 47-37323, when the object to be processed is a wet granulated material, the swelling phenomenon of the object to be processed can be improved by the heat exchange chamber consisting of radial small chambers. Even if it is done,
The material to be treated enters the heat exchange chamber from the bottom, moves to the top by the rotation of the kiln, and is dried by contact with hot gas while sliding and falling along the sloped bottom plate and partition plate of the heat exchange chamber. Therefore, it cannot be said that contact between the object to be treated and the hot gas is sufficient just by providing one heat exchange chamber.

Therefore, in order to achieve uniform and sufficient drying, it is necessary to provide several stages of heat exchange chambers along the length of the kiln, which significantly increases the overall length of the kiln. Furthermore, the objects to be processed move violently in each heat exchange chamber, and the objects to be processed are crushed and powdered by the impact caused by falling from a high position at the exit of each stage of heat exchange chambers. There is also the problem of an increase in

The technical object of this invention is to prevent the raw material from becoming swollen, disintegrated, and powdered in a single drying chamber, and to increase the contact between the processed material and the hot gas to achieve uniform drying.

[Means for solving problems]

The technical measures taken to solve the above problems were to arrange a substantially cylindrical inner wall concentrically in the drying chamber of the rotary kiln, and to install a large number of partition plates in the front and back direction between this inner wall and the inner peripheral surface of the body. They are fixed radially to form a large number of drying passages in the front and back direction between each partition plate, and a large number of inclined feeding blades are fixed on both sides of each partition plate to guide the processed material forward. A guide means is provided at the inlet side end of each drying passage for guiding the processed material supplied from the supply port into each drying passage, and a guiding means is provided at the discharge port side end of each drying passage. A fall prevention gutter is provided to prevent objects to be processed from falling from the end of the partition wall closer to the inner wall.

[Effect]

The technical means of the present invention is as described above, and the material to be treated is introduced into the body of the rotary kiln from the supply port and flows into the drying passage from the inlet. As the kiln rotates, the raw material that has entered this passage is silently and continuously transferred within this passage while repeating rolling and feeding by opposing inclined blades.

In the process of transferring the material to be treated in this way, it is dried by heat exchange with the countercurrent hot gas and discharged into the kiln from the outlet of the drying passage. Therefore, the layer of the object to be treated moves within the passage while being repeatedly turned over, so that it is evenly contacted with the countercurrent hot gas.

〔Example〕

In Fig. 1, 1 is the body of the rotary kiln, which has a cylindrical shape lined with refractory material, and has a gentle downward slope so that the front side, that is, the discharge port side (not shown) is at the bottom, similar to known rotary kilns. It is rotatably supported by an appropriate support means at an inclination, rotated by an appropriate drive means, and high-temperature combustion gas fed by a burner provided on the exhaust port side flows rearward inside the fuselage 1. .

Further, the rear end of the body 1 serves as a supply port 2 for the material to be processed, which also serves as an outlet for combustion gas, and a supply chute 3 faces here.

Reference numeral 4 denotes an inner wall provided in the drying chamber A at the rear of the fuselage 1, which has a substantially cylindrical shape as shown in FIGS.
It is fixed concentrically to the Further, the rear end of the inner wall 4 forms a tapered portion 6 with an open rear end.

Each partition plate 5 spans the entire length of the inner wall 4 and is arranged radially at regular intervals, and between each partition plate 5 there is a large number of drying passages 8 which are open at the front and rear ends and are long in the front and rear direction. .

A large number of inclined feeding blades 11 and 12 are provided on both sides of each of the partition plates 5, respectively.
1 and 12 are inclined in opposite directions. That is,
On the side where the workpiece is placed on the partition plate 5 and rotated, the blades 11 and 12 are inclined in such a way that the workpiece slides forward.

A scraping plate 13 and a weir plate 14a are provided on the entrance side of each drying passage 8 as means for guiding the material to be treated.
The scraping plate 13 is slightly inclined from the fold 15 at the end of the partition plate 5 in the direction in which the partition plate 5 rotates, as shown in FIGS.
is facing the opposite.

A fall prevention gutter 16 is provided at the front end of each partition plate 5. This prevention gutter 16 is provided on the inner wall 4 side of the upper surface of the partition plate 5 on the side rotating downward as shown in FIGS. 4 and 5, and the front end of this gutter 16 is closed with an end plate 17. , the rear end becomes a weir plate 18 provided along the front edge of the partition plate 5 that slopes rearward, and the area between the end of this weir plate 18 and the inner surface of the body 1 is used for baking the workpiece in the front of the drying chamber A. Exhaust port 19 for discharging to chamber B
It is becoming.

Further, a disc-shaped baffle plate 20 is fixed concentrically at the front center of the drying chamber A with a plurality of brackets 21 so that most of the combustion gas flows into each passage 8.

Next, the operation of the above embodiment will be explained.

The body 1 of the rotary kiln is rotated in the direction of the arrows in FIGS. 2 to 5, and the combustion gas is of a countercurrent type in which it flows from the right to the left in FIG.

A workpiece 22 consisting of a wet granulated material such as ore is introduced by a supply chute 3 into the entrance of a drying passage 8 located below.

The input object 22 to be processed enters the lower passage 8, initially rests on the inner surface of the body 1, moves upward, is guided by the scraping plate 13, rests on the partition plate 5, and on the way moves upward. Natsuta inclined feed blade 12
As a result, it slides forward and descends while resting on the upwardly facing inner wall 4.

In the descending process, the workpiece 22 is separated from the partition plate 5
It enters the baking chamber B in the body from the discharge port 19 while sliding forward along the blade 11, but the fall prevention gutter 1 at the front end of the partition plate 5
The material to be processed that has entered the chamber 6 is discharged from the discharge port 19 near the inner surface of the body 1 to the firing chamber B in front along the weir plate 18 following the gutter 16. In this manner, while the objects to be processed move through each drying passage 8, they are brought into contact with the combustion gas flowing in the direction opposite to the direction of movement of the objects, and are dried.

〔effect〕

In this invention, a concentric cylindrical inner wall is provided in a drying chamber provided in the rear part of the body of a rotary kiln, and a number of drying passages in the front and rear directions are provided by this inner wall and a number of partition plates provided in the body. Since the inclined feed blades are provided on both sides of the plate in different directions, the layers of the material to be processed in the passage are moved while being repeatedly turned over as the kiln rotates. As a result, the opportunity for contact with the high-temperature countercurrent combustion gas is greatly increased, and the particles of each object to be treated come into contact almost evenly, making it possible to perform extremely uniform drying without uneven drying. Continuous flow of processed material,
Moreover, its movement is extremely smooth and quiet.

Therefore, sufficient drying can be achieved even if the drying path is shortened, so the overall length of the path, that is, the drying chamber, can be shortened.

Further, since a drop prevention gutter is provided at the front end of the drying passage to prevent the objects to be processed from falling from a high position, it is possible to prevent the objects to be dried and to be powdered by falling.

In addition, by appropriately selecting the mounting angle and number of the inclined feed blades, there is an effect that the residence time of the raw material in the drying chamber can be arbitrarily set.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway vertical side view showing an embodiment of the rotary kiln of the present invention, and FIG.
Partially cutaway enlarged cross-sectional view of the line, Figure 3 is Figure 1-
A partially cutaway enlarged sectional view of the line, Figure 4 is Figure 1.
FIG. 5 is an enlarged partially cutaway sectional view of the line, and FIG. 5 is a partially cutaway enlarged perspective view of the partition plate. DESCRIPTION OF SYMBOLS 1... Body, 2... Supply port, 4... Inner wall, 5... Partition plate, 8... Drying passage, 11, 12... Inclined feed blade,
13... Raising board, 16... Fall prevention gutter, 19... Outlet, A... Drying chamber, B... Baking chamber.

Claims (1)

[Claims] 1 In a rotary kiln that has a drying chamber at the rear of a cylindrical body that has an exhaust port at the front end and a supply port at the rear end, and is installed at an angle so that the discharge port side is lower, this drying chamber has an approximately cylindrical shape. In addition to arranging the shaped inner walls concentrically, between this inner wall and the inner peripheral surface of the fuselage,
A large number of partition plates in the front and back directions are fixed radially, and a large number of drying passages in the front and back directions are formed between each partition plate, and both sides of each partition plate are sloped to guide the processed material forward. A large number of inclined feeding blades are fixed, and guiding means is provided at the inlet side end of each drying passage to guide the processed material supplied from the supply port into each drying passage. A rotary kiln characterized in that a fall prevention gutter is provided at an end of each partition wall to prevent the workpieces at the upper end of each partition wall from falling from the end closer to the inner wall of the partition wall.