JP4493797B2 - How to remove deposits at the rotary kiln outlet - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for removing deposits at a rotary kiln outlet.
[0002]
[Prior art and problems to be solved by the invention]
The rotary kiln has a cylindrical shape, and its central axis is rotated from the upstream to the downstream with respect to the horizontal, and the waste or the metal-containing waste and the reducing agent are introduced from the inlet at the upstream opening end. While introducing the combustion gas and moving the waste toward the downstream opening end (or outlet end), molten slag or molten metal and molten slag are generated, and molten slag or molten metal and molten slag are overflowed from the outlet end. It will flow down. However, overflowing molten slag or molten metal and a part of the molten slag adhere to the outlet end surface and solidify, and if the rotary kiln is operated for a long time, the deposit on the outlet end becomes enormous, and finally the molten metal and molten slag are difficult to flow down. There is a problem that the adhering material that has become large or exfoliates at a stretch for some reason and falls into the cooling water tank below, causing a steam explosion.
[0003]
Conventionally, when such a deposit situation occurs, the rotary kiln is stopped and cooled to near room temperature, and then the deposit is removed manually. However, manual removal of deposits has the problem of reducing the operating rate of the rotary kiln, and it is difficult to remove deposits by hand in the rotary kiln, which takes a long time or complete removal. There is a problem that the operation rate of the rotary kiln is shortened because there are things that cannot be done. Further, there is a problem in that the removal work of the deposit by manual work is a dangerous work that may be accompanied by injury of the worker due to the fall of the deposit.
[0004]
The present invention has been intensively studied in view of such problems, and an object of the present invention is to provide a method for automatically and safely removing deposits at the rotary kiln outlet.
[0005]
[Means for Solving the Problems]
The object is to remove deposits at the outlet of the rotary kiln according to the present invention according to claim 1, that is, the long axis of the water-cooled scraper faces the radial direction of the rotary kiln and is parallel to the outlet end face of the rotary kiln. As described above, place a rod-shaped water-cooled scraper in the vicinity of the rotating rotary kiln outlet end surface, and scrape off the adhering material adhering to the rotary kiln outlet end surface by the side, side or tip of the scraper. This is achieved by a method for removing deposits at the rotary kiln outlet.
[0006]
Further, the object is to remove the deposit on the rotary kiln outlet according to the present invention according to claim 2, that is, the long axis of the water-cooled scraper faces the radial direction of the rotary kiln and is parallel to the outlet end face of the rotary kiln. A stick-shaped water-cooled scraper is installed in the vicinity of the exit end face of the rotating rotary kiln so that the adhering matter adheres to the exit end face of the rotary kiln and is scraped off by a blade attached to the scraper. This is achieved by a method for removing deposits at the rotary kiln outlet.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0008]
First Embodiment FIG. 1 is a plan sectional view in which a scraper according to an embodiment of the present invention is disposed near the outlet end of the rotary kiln, and FIG. 2 is a diagram of the scraper according to the embodiment of the present invention disposed near the outlet end of the rotary kiln. It is a front view.
[0009]
The exit end face 101 of the rotary kiln 1 has an annular shape. The rotary kiln 1 rotates at a constant speed around the central axis 3 in the direction of arrow 2.
[0010]
A rod-shaped scraper 4 is disposed in the vicinity of the outlet end face 101 of the rotary kiln. In the first embodiment, the long axis of the scraper 4 is arranged in the radial direction of the rotary kiln and parallel to the outlet end face 101. The scraper 4 is a rod having a square cross section, and the left side 402 of the scraper 4 is closest to the outlet end surface 101 in parallel, and an adhering material (not shown) attached to the outlet end surface 101 is scraped off by the side 402 of the scraper. Or, it inhibits the growth of deposits. That is, the scraper 4 is installed stationary near the outlet end surface 101 of the rotary kiln 1, while the rotary kiln 1 rotates around the central axis 3 so that the deposits attached to the outlet end surface 101 are sequentially deposited. It contacts the left side 402 of the scraper 4 and is scraped off or hinders the growth of deposits.
[0011]
The arrangement position of the scraper 4 is such that the long axis of the scraper is parallel to a desired distance from the outlet end face 101 of the rotary kiln, for example, 20 mm to 500 mm, and the long axis of the scraper is substantially coincident with the horizontal radius of the rotary kiln. Alternatively, the rotary kiln is positioned at a desired angle, for example, 1 ° to 5 ° upward in the rotational direction of the rotary kiln. Further, the tip surface 401 of the scraper 4 is disposed so as to protrude from the inner surface 102 of the rotary kiln toward the central axis 3, but unlike the embodiment shown in FIG. 2, the tip surface 401 of the scraper 4 is more than the inner surface 102 of the rotary kiln. Adjustment is possible so as not to protrude in the direction of the central axis 3.
[0012]
In the first embodiment, the scraper 4 is provided with an opening 502 in a part of the side wall 501 of the secondary combustion chamber 5 provided in contact with the outlet of the rotary kiln 1. A scraper 4 is inserted from the outside. A heat insulating material (not shown) may be filled between the scraper 4 and the opening 502 to prevent the heat inside the secondary combustion chamber 5 from being released to the outside.
[0013]
Further, in the first embodiment, the lower surface 405 of the scraper 4 that is outside the secondary combustion chamber 5 is placed on the scraper receiver 6 in contact with the rollers 601 and 602. The scraper 4 can be taken in and out in the radial direction of the rotary kiln 1. Therefore, when the metal or slag begins to adhere to the outlet end face 101 of the rotary kiln, the scraper 4 can be inserted into the secondary combustion chamber 5 and the position can be finely adjusted. The scraper 4 can be easily taken out.
[0014]
Since the vicinity of the rotary kiln outlet is hot and the deposits are also hot, the scraper 4 is preferably cooled, particularly water-cooled. A cooling water supply port 411 is provided on the rear end surface 403 of the scraper 4, and a cooling water discharge port 410 is provided on the upper side surface 404 near the rear end surface 403. Although other known methods can be used for cooling the scraper 4, water cooling is desirable from the viewpoint of fire resistance, flammability, economy, and ease of operation.
[0015]
A blade (not shown) may be attached to a desired length near the front end surface 401 on the left side surface of the scraper 4. The blades are used to actively scrape off deposits adhering to the outlet end face 101. When the blade is deteriorated, only the blade can be replaced with a new one or repaired and attached to the scraper 4.
[0016]
Second Embodiment FIG. 3 is a front view of a scraper according to a second embodiment of the present invention, and FIG. 4 is an enlarged side view of the scraper according to a second embodiment of the present invention.
[0017]
The scraper of the second embodiment is mainly different from the scraper of the first embodiment in the following two points.
[0018]
First, the scraper of the second embodiment is fixedly installed outside the secondary combustion chamber. That is, the scraper receiver 7 is installed outside the secondary combustion chamber, and the rear end portion of the scraper 4 is placed on the receiving base 701 of the scraper receiver 7 and fixed by the fixing tools 702 and 703.
[0019]
2ndly, the scraper of 2nd Embodiment differs in the point which scrapes off the deposit | attachment adhering to the rear-end surface of a rotary kiln with the side part 424 and front-end | tip part near the front-end | tip part by the square cross-section column shape. Reference numerals 420, 421, 422, and 423 are side surfaces of the scraper. The diagonal line passing through the side 424 of the cross section of the scraper is disposed so as to pass through the center of the rotary kiln, but is disposed at a position delayed from the horizontal radius by an angle θ in the rotational direction of the rotary kiln. θ is preferably 1 ° to 5 °. The distance between the side 424 of the scraper and the exit end face of the rotary kiln is L, and L is 20 mm to 500 mm.
[0020]
As another embodiment, a chip such as a plurality of cutting blades may be attached to the scraper. The tip is used to scrape off the deposits.
[0021]
Furthermore, as another embodiment, the scraper may have a rectangular, circular, triangular, or polygonal cross-sectional shape, and the adhering material adhering to the outlet end surface of the rotary kiln may be scraped off by the side, side, or tip. FIG. 5 is a front view of a scraper according to a third embodiment of the present invention. The tip portion 431 of the scraper 4 has a circular cross section and is smaller in diameter and narrower than the rear portion 432. A front end portion 431 of the scraper 4 is disposed in the vicinity of the rear end surface 101 of the rotary kiln. Moreover, the adhering material adhering to the outlet end face 101 of the rotary kiln is scraped off while rotating the scraper 4 around its long axis. Moreover, it is the structure which can move the scraper 4 to a major axis direction as needed, and can adjust a position.
[0022]
FIG. 6 is a schematic view showing a position where the scraper of the present invention is arranged near the exit end face of the rotary kiln. Scrapers 41, 42, 43 are installed near the exit end face 101 of the rotary kiln 1, but the rotary kiln 1 rotates in the direction of the arrow 2 and coincides with a horizontal plane 31 passing through the center 3 after passing through the lowermost part 111. 41 is disposed, and the scraper 42 is disposed at the uppermost portion 113 of the rotary kiln 1 and coincides with the vertical plane 32 passing through the center 3, while the scraper 42 is perpendicular to the horizontal plane 31 of the rotary kiln. It is disposed at an intermediate position with respect to the surface 32.
[0023]
FIG. 7 is another schematic view showing a position where the scraper of the present invention is disposed near the exit end face of the rotary kiln. The rotary kiln 1 rotates in the direction of the arrow 2 and is parallel to the horizontal plane 31 passing through the center 3 after passing through the lowermost part 111, and is arranged offset upward by a distance L (off).
[0024]
【The invention's effect】
In the method for removing deposits at the outlet of the rotary kiln according to the present invention, a stick-shaped water-cooled scraper is placed close to the outlet end surface of the rotary kiln, and the deposits attached to the outlet end surface of the rotary kiln are removed from the side or side of the scraper. Since the blade attached to the scraper is scraped off, the deposit that starts to adhere to the rotary kiln outlet reaches a predetermined size and starts to contact the scraper. Therefore, it is not necessary to stop the operation of the rotary kiln, and not only the operating rate of the rotary kiln is improved, but also the huge deposits do not fall into the water tank at a stretch for some reason, making it safer and more stable The effect that it can operate is acquired. In addition, there is no need for the manual removal work of deposits, and the work can be performed more safely.
[0025]
In the method for removing deposits at the rotary kiln outlet according to the present invention, a stick-shaped water-cooled scraper is placed close to the outlet end surface of the rotary kiln, and the deposits adhering to the outlet end surface of the rotary kiln are attached to the side, side, and tip of the scraper. Or the blade attached to the scraper scrapes off or inhibits the growth of deposits. When deposits that start to adhere to the rotary kiln outlet end surface become a predetermined size and start to contact the scraper, As a result, deposits are scraped off, the state of the outlet end face of the rotary kiln is always kept constant, and it is easy to control the overflow of molten metal or molten slag.
[Brief description of the drawings]
FIG. 1 is a plan sectional view in which a scraper according to a first embodiment of the present invention is disposed near an outlet end of a rotary kiln.
FIG. 2 is a front view in which the scraper according to the first embodiment of the present invention is arranged near the outlet end of the rotary kiln.
FIG. 3 is a front view in which a scraper according to a second embodiment of the present invention is disposed near the outlet end of a rotary kiln.
FIG. 4 is an enlarged side view in which a scraper according to a second embodiment of the present invention is disposed near the outlet end of a rotary kiln.
FIG. 5 is a front view of a scraper according to a third embodiment of the present invention.
FIG. 6 is a schematic view showing a position where the scraper of the present invention is arranged near the exit end face of the rotary kiln.
FIG. 7 is another schematic view showing a position where the scraper of the present invention is disposed near the exit end face of the rotary kiln.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotary kiln 101 Outlet end surface 102 Inner surface 111 Lowermost part 113 Uppermost part 3 Central axis 31 Horizontal surface 32 Vertical surface 4 Scraper 401 Front end surface 402 Left side surface 403 Rear end surface 404 Upper side surface 405 Lower side surface 410 Discharge port 411 Water supply port 420 Side surface 421 Side surface 422 Side surface 423 Side surface 424 Side edge 431 Front end portion 432 Rear portion 5 Secondary combustion chamber 501 Side wall 502 Opening 6 Scraper receiver 601 Roller 602 Roller 7 Scraper receiver 701 Receiving base 702 Fixing tool 703 Fixing tool

Claims (2)

A rod-shaped water-cooled scraper is installed stationary near the outlet end face of the rotating rotary kiln so that the long axis of the water-cooled scraper faces the radial direction of the rotary kiln and is parallel to the outlet end face of the rotary kiln. A method for removing deposits from a rotary kiln outlet, characterized in that deposits adhering to the outlet end surface of the rotary kiln are scraped off by the side, side or tip of the scraper. A rod-shaped water-cooled scraper is installed stationary near the outlet end face of the rotating rotary kiln so that the long axis of the water-cooled scraper faces the radial direction of the rotary kiln and is parallel to the outlet end face of the rotary kiln. A method of removing deposits on a rotary kiln outlet, wherein deposits adhering to an outlet end face of the rotary kiln are scraped off by a blade attached to the scraper.

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