JPH0150834B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial 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]

The process of drying and firing the processed material, such as wet granules, is performed continuously in the rotary kiln, and the flow of the processed material in the drying chamber is made continuous and smooth to prevent the processed material from turning into powder. For this purpose, a rotary kiln with a single drying chamber installed at the rear of the rotary kiln was proposed in Japanese Patent Application No. 195961/1983.

This rotary kiln has a single-stage drying chamber in the rear part of the fuselage, consisting of a large number of radial drying passages in the front and back direction, which has a substantially cylindrical concentric inner wall, and the radial partition plates of each drying passage have drying chambers on both sides. A large number of inclined feeding blades are fixed so as to guide the processed material forward, and a scraper plate and a weir are installed at the inlet end to guide the supplied processed material into each drying passage. A guide means made of a plate is provided, and a fall prevention gutter is also provided at the discharge side end to prevent the dried material to be processed from falling and turning into powder.

[Problem that the invention seeks to solve]

The rotary kiln described in the above-mentioned Japanese Patent Application No. 59-195961 is provided with a scraping plate at the inlet end of each drying passage, so that the material to be processed fed from the supply port is distributed to each drying passage. Care has been taken to minimize the amount of feedback that falls from the entrance end when the body rotates and is pulled up, but the feedback at the entrance of the drying chamber accumulates and remains in an equilibrium state at a certain material layer thickness. becomes. Therefore, the scraping plate alone is not sufficient as a means for guiding the material to be processed, and the diffusion of evaporated water from the wet granules becomes insufficient, causing the material to soften and collapse at the entrance of the drying chamber, and drying due to reduced strength. There is a problem in that it leads to powdering during the firing process.

The technical object of this invention is to significantly reduce the swelling, disintegration, and strength loss of wet granules during the drying process by smoothing out the retention of raw materials at the entrance of the drying chamber.

[Means for solving problems]

The technical measure taken to solve the above problem was to create an annular protrusion around the entire circumference on the inside near the rear end of the fuselage, and to place a cylindrical inner wall concentrically around the inner circumference of the fuselage in front of this protrusion. It is fixed and has a roughly V-shaped longitudinal section that protrudes inward with a steep slope at the front and a gentle slope at the rear.
The shaped inner cylinder is fixed such that the front end of its steep slope is connected to the rear end of the inner wall, and the rear end of the gentle slope is located rearward than the annular protrusion, and the inner wall and V
A large number of partition plates in the front and rear directions are fixed radially between the inner cylinder and the inner circumferential surface of the body, and a large number of drying passages in the front and rear directions are formed between each partition plate. A drying chamber is provided in which a large number of inclined feeding blades are fixed so as to guide objects forward, and a scraper plate is provided at the entrance side end of the rear end of each of the drying passages to guide objects to be processed into each passage. provided and said V
A cone with a small diameter at the front is fixed concentrically near the V-shaped inner cylinder through partition plates arranged radially, and a tapered guide passage is formed between this cone and the gentle slope of the V-shaped inner cylinder. was formed.

[Effect]

The technical means of this invention is as described above, in which the material to be processed is introduced from the supply chute at the supply port at the rear end of the fuselage and flows down the bottom of the taper at the rear of the fuselage.
It enters the drying passage located below through the entrance of the drying chamber. At this time, the amount of inflow is limited by the steep slope on the rear side of the protrusion.

The object to be processed, which has entered the lower drying passage, is lifted upward as the body rotates. During this rotation from the bottom to the top, the material to be processed is guided to the front of the drying passage by the scraping plate, and the material to be processed behind the annular protrusion in the passage falls onto the gentle slope of the V-shaped inner cylinder. , it slides down the gentle slope with the action of the inclined feed blade, and is sent to the rear of the steep slope of the inner cylinder in front of it.

Then, while the body rotates, that is, the drying passage moves from the top to the bottom, the processed material in the recess of the V-shaped inner cylinder in this passage falls onto the gentle slope of the annular protrusion, and moves along the gentle slope. Together with the action of the vanes, it is reliably sent to the front of the annular projection.

As a result, there is extremely little accumulation of material to be processed due to falling (feedback) at the inlet end.
The inlet end of the drying passage is always in an empty state, and the objects to be treated can smoothly flow into the passage.

In this way, the raw material that has entered the drying passage is rolled and rotated in this passage as the kiln body rotates.
It is silently and continuously transferred while being repeatedly fed by opposing inclined blades.

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

In the above case, the falling object (feedback) from the end of the passage entrance is received by a cone with a small diameter at the front, which is a feature of the second invention, and is guided by the guide passage on the tapered cylindrical outer surface of this cone. The material is then sent to the inside surface of the inner wall of the drying chamber, and is then dried by hot air as it rolls within the inner wall, enters the firing chamber from the end of the inner wall, and joins the material to be processed from the drying passage.

〔Example〕

In the embodiment of the first invention shown in FIGS. 1 to 5, 1 is a rotary drum body of a rotary kiln having a discharge port (not shown) at the front end and a supply port 2 at the rear end, and is lined with refractory material. It has a cylindrical shape, and is rotatably supported by appropriate support means with a gentle downward slope so that the front side, that is, the discharge port side (not shown) is facing down, as in a known rotary kiln. rotated by an appropriate driving means,
In addition, high-temperature combustion gas sent by a burner provided on the exhaust port side flows rearward within the body 1.

The body 1 includes a straight body part 1a and a tapered part 1 at the rear end.
b, and this tapered portion becomes larger in diameter toward the front straight body portion 1a.

The supply port 2 is for the object to be processed and also serves as an outlet for combustion gas, and a supply chute 3 faces here.

Reference numeral 4 denotes an annular protrusion provided inside the connecting portion between the straight body portion 1a and the tapered portion 1b of the body 1, and the supply port 2 side is a steep slope 4a, and the discharge port side is a gentle slope 4b.

A is a drying chamber provided at the rear of the fuselage 1, and this drying chamber is constructed as follows.

5 is a substantially cylindrical inner wall arranged concentrically within the fuselage 1.

Reference numeral 6 denotes a V-shaped inner cylinder with a substantially V-shaped longitudinal section that is arranged concentrically with the body and protrudes inward, and has a gentle slope 6a on the rear supply port 2 side and a steep slope 6b on the front discharge port side. A front end thereof is connected to the inner wall 5, and an inlet 6d is defined between the tapered portion 1b and the rear end of the gentle slope 6a.

The chevron-shaped top end 4c of the annular protrusion 4 is connected to the V
It is slightly shifted toward the supply port 2 from the top end 6C of the inner cylinder 6 in the axial direction of the body 1.

That is, the top end 4c of the annular projection 4 is within the gentle slope 6a of the V-shaped inner cylinder 6, and the top end 6c of the V-shaped inner cylinder 6
is located within the gentle slope 4b of the annular protrusion 4.

The inner wall 5 and the V-shaped inner cylinder 6 are concentrically fixed to the body 1 over the entire length by a large number of partition plates 7 arranged radially at regular intervals.
There are a number of drying passages 8 which are long in the front-rear direction and whose front and rear ends are open.

A large number of inclined feeding blades 11 and 12 are provided on both sides of each of the partition plates 7, respectively.
1 and 12 are inclined in opposite directions. That is,
On the side where the workpiece is placed on the partition plate 7 and rotated, the blades 11 and 12 are inclined in such a way that the workpiece slides forward.

A scooping plate 13, a weir plate 14a, and a weir plate 14b are provided on the inlet 6d side of the V-shaped inner cylinder 6 at the rear 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 7 in the direction in which the partition plate 7 rotates, as shown in FIGS. It is provided at the end, and the weir plate 14b faces in the opposite direction.

A fall prevention gutter 16 is provided at the front end of each partition plate 7. This prevention gutter 16 is provided on the inner wall 5 side of the upper surface of the partition plate 7 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 7 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. Discharge section 19 that discharges 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 embodiment of the first invention will be explained.

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

The material to be treated is introduced from the supply chute 3 of the supply port 2 in FIG. 1, flows down the bottom of the tapered portion 1b of the body 1, passes through the inlet 6d, and enters the drying passage 8 located below. At this time, the amount of penetration is limited by the steep slope 4a of the annular protrusion 4.

In this way, the objects to be treated that have entered the lower drying passage 8 are lifted upward as the body 1 rotates. During this rotation from the bottom to the top, the object to be treated is guided to the front of the drying passage 8 by the scraping plate 13, and the object to be treated before the steep slope 4a in the passage 8 is removed from the gentle slope 6a of the V-shaped inner cylinder 6. It falls upward, slides down the gentle slope 6a with the action of the inclined sending blade 12, and is sent to the front of the steep slope 6b.

Then, the rotation of the body 1, that is, the drying passage 8
While moving from above to below, the material to be processed in front of the steep slope 6b in this passage falls onto the gentle slope 4b of the protrusion 4, and is reliably moved forward on this gentle slope 4b by the action of the blade 11. It is sent. 6 and 7 show embodiments of the second invention, most of which are the same as those of the first invention, so the same parts are given the same reference numerals and a description thereof will be omitted.

The feature of this second invention is that a cone 32 having a vertical wall 31 is provided concentrically inside the V-shaped inner cylinder 6.

That is, the cone 32 has a tapered shape with the discharge port side reduced, the tip thereof is closed (or may be open), the rear end is open, and a flange-shaped standing wall 31 is formed around the entire circumference. There is.

The cone 32 is fixed to the V-shaped inner cylinder 6 by a plurality of axial partition plates 33 arranged radially, and a tapered guide passage 34 with open front and rear ends is formed between the inner cylinder 6 and the cone 32. form.

Vertical wall 31 at the end of the cone 32 on the supply port 2 side
The part is located slightly behind the rear end of the V-shaped inner cylinder 6, and the cone 32 receives the material to be treated spilled from the rear end of the inner cylinder 6 that has rotated upward, and guides the cone 32 into the guide passage on its outer peripheral surface. 34 to the front firing chamber B
It has the effect of causing it to fall.

Other functions are the same as in the first invention.

〔Effect of the invention〕

With the above-described configuration, the present invention can smoothly and reliably transport the material to be treated, and can smooth out the accumulation of the material at the entrance of the drying chamber.

That is, in this invention, an annular protrusion is provided on the inner side near the rear end of the fuselage, and a cylindrical inner wall is fixed concentrically to the inner circumference of the fuselage in front of the protrusion.
A V-shaped inner cylinder having a substantially V-shaped vertical cross section with a steep slope at the front and a gentle slope at the rear, the front end of the steep slope connecting to the rear end of the inner wall, and the rear end of the gentle slope extending rearward from the annular protrusion. Since the object is fixed in position, the object to be processed introduced from the supply port is smoothly transferred from the gentle slope of the inner cylinder to the front of the annular projection as the body rotates.

Therefore, the evaporated water generated from the wet granulated material to be processed is smoothly diffused, and the granulated material is prevented from softening and collapsing at the entrance of the drying chamber, and from decreasing its strength. Thermal efficiency is significantly improved, and there is almost no collapse due to swelling due to falling (feedback) retention of the processed material.

In addition, in the second invention, by providing a cone with a reduced front part, it is possible to actively utilize the heat exchange effect, and the length of the drying chamber can be made as short as possible. This method is effective for objects to be treated that do not cause bursting.

Furthermore, since there is no decrease in strength during the drying process, the number of rotations of the body can be increased and the capacity of the rotary kiln as a whole can be increased.

[Brief explanation of drawings]

Fig. 1 is a partially cut away vertical sectional side view showing an embodiment of the rotary kiln of the first invention, Fig. 2 is a partially cut away enlarged sectional view taken along the line shown in Fig. 1, and Fig. 3 is an enlarged sectional view taken along the line shown in Fig. FIG. 4 is a partially cutaway enlarged sectional view taken along the - line in FIG. 1, FIG. 5 is a partially cutaway enlarged perspective view of the partition plate, and FIG. A partially cutaway vertical side view showing the embodiment, FIG.
It is a partially cutaway enlarged sectional view of the figure-line. 1... body, 2... supply port, 4... annular projection,
5... Inner wall, 6... V-shaped inner cylinder, 7... Partition plate, 8
... Drying passage, 11, 12 ... Inclined feed blade, 4
a, 6b...steep slope, 4b, 6a...gentle slope, 3
1... standing wall, 32... cone, 33... partition plate,
34... Guidance passage.

Claims (1)

[Scope of Claims] 1. In a rotary kiln in which a cylindrical body having a discharge port at the front end and a supply port at the rear end is installed in an inclined manner, an annular protrusion extending over the entire circumference is provided inside the body near the rear end, A cylindrical inner wall is fixed concentrically to the inner periphery of the fuselage in front of this protrusion, and a V-shaped inner cylinder with an approximately V-shaped longitudinal section that protrudes inward with a steep slope at the front and a gentle slope at the rear is connected to the steep slope. is fixed such that the front end thereof is connected to the rear end of the inner wall, and the rear end of the gentle slope is positioned rearward than the annular protrusion, and between the inner wall, the V-shaped inner cylinder, and the inner circumferential surface of the body, a A large number of partition plates 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 slopes are provided on both sides of each partition plate to guide the processed material forward. 1. A rotary kiln, characterized in that a drying chamber having a fixed feeding blade is provided, and a scraping plate is provided at the rear end of each of the drying passages on the inlet side for guiding the material to be processed into each passage. 2. In a rotary kiln that has a cylindrical body with a discharge port at the front end and a supply port at the rear end installed in an inclined manner, an annular protrusion extending all the way around the inside of the body near the rear end is provided, and the area in front of this protrusion is A cylindrical inner wall is concentrically fixed to the inner periphery of the fuselage, and a V-shaped inner cylinder with an approximately V-shaped longitudinal section protrudes inward with a steep slope at the front and a gentle slope at the rear, with the front end of the steep slope facing the inner wall. connected to the rear end and fixed so that the rear end of the gentle slope is located rearward from the annular protrusion, and a large number of partition plates in the front-rear direction are installed between the inner wall, the V-shaped inner cylinder, and the inner circumferential surface of the body. The dryer is fixed in a radial manner 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 area forward. A scooping plate is provided at the inlet side end of the rear end of each drying passage for guiding the material to be treated into each passage;
A cone with a small diameter front part is fixed concentrically near the inner cylinder through partition plates arranged radially, and a tapered guide passage is formed between this cone and the gentle slope of the V-shaped inner cylinder. Rotary kiln formed.