JPH05317743A - Device for preventing blocking of coal feed pipe - Google Patents

Abstract

PURPOSE:To prevent fine coal from attaching to the inner wall of a coal feed pipe for feeding coal to a mill for coal fired boiler, thus preventing blocking of the pipe. CONSTITUTION:By boring a hole through the pipe wall of a scraper pipe inserted into a coal feed pipe to blow off hot air, by allowing the scraper itself to serve as a pipe heater or microheater, by providing an outer cylinder 32 surrounding a coal feed pipe 31 and winding heating wire 35 around the outer cylinder, or by feeding hot air into a space between the outer cylinder and the coal feed pipe, the coal feed pipe and scraper are heated to high temperature. As a result, fine coal is dried so that it is prevented from being attached to the coal feed pipe 31 and the scraper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents powder coal from adhering to the inner wall of a powder supply pipe, particularly a coal supply pipe for supplying coal to a coal-fired boiler mill, and clogging the pipe. The present invention relates to a coal feeding pipe blockage prevention device.

[0002]

2. Description of the Related Art FIG. 6 is a vertical sectional side view showing an example of a conventional coal feeding pipe, and FIG. 7 is an enlarged horizontal sectional view of the same. In these drawings, 1 is a vertical cylindrical coal feed pipe, 2 is a scraper, 3 is a claw attached to the scraper 2, 4 is the above-mentioned coal feed pipe 1
It is a hopper attached to the upper part of. Further, 5 is a mill (pulverized coal pulverizer), 6 is a conveyor, 7 is a motor, 8 is a reducer, 9 is pulverized coal on the conveyor, and 10 is pulverized coal being charged.

The coal feeding pipe 1 is rotated by a motor 7 via a speed reducer 8. The inserted scraper 2 has the claw 3 and keeps the stationary state. The hopper 4 at the upper end of the coal feeding pipe is the conveyor 6
The pulverized coal 10 is for receiving the pulverized coal 9 containing a small amount of moisture, which has been carried in. The charged pulverized coal 10 drops through the rotating hopper 4 and the coal feeding pipe 1 and enters the mill 5. As described above, since the stationary scraper 2 is inserted into the coal feeding pipe 1 and the coal feeding pipe 1 rotates at a predetermined rotation speed, the pulverized coal attached to the inner wall of the coal feeding pipe 1 is scraped off by the scraper 2. ..

[0004]

In the case of pulverized coal containing moisture, especially in a small-scale plant such as a boiler for private power generation or a pilot plant, the diameter of the coal feeding pipe is small, and therefore the hopper 4 and the feeding pipe 1 are lowered. Pulverized coal adheres to the surface of the inserted scraper over time. Then, the scraper 2 deteriorates its original function of scraping off the pulverized coal adhered to the inner wall of the coal feeding pipe by the claws 3, and eventually the coal feeding pipe 1 may be closed and the operation may be stopped.

[0005]

In order to solve the above-mentioned conventional problems, the present invention proposes the following coal feed pipe blockage prevention device. (1) A coal feed pipe for supplying coal to a coal-fired boiler mill is configured to be vertical and rotatable about an axis, and a stationary scraper pipe having a plurality of through holes in a pipe wall is inserted into the coal feed pipe. And a means for supplying heated gas to the scraper pipe, the coal feed pipe blockage prevention device.

(2) The coal feed pipe for supplying coal to the coal-fired boiler mill is constructed to be vertical and rotatable about its axis, and a pipe heater or a micro heater is inserted as a scraper into the coal feed pipe. A coal feed pipe blockage prevention device.

(3) Blocking of a coal feeding pipe characterized in that a coaxial outer casing is provided around a coal feeding pipe for supplying coal to a coal burning boiler mill, and a heating wire is attached to the outer casing. Prevention device.

(4) A coaxial outer cylinder is provided surrounding a coal feeding pipe for supplying coal to a coal burning boiler mill, and a space having an annular cross section formed between the outer casing and the coal feeding pipe. An apparatus for preventing blockage of a coal feeding pipe, characterized in that a means for supplying heated gas is provided in the.

[0009]

In the solution means (1), the heated gas is supplied to the scraper pipe, and hot air having a predetermined pressure and temperature is continuously or intermittently supplied from a plurality of through holes provided in the pipe wall of the scraper pipe. Blow out. Then, in addition to the blowing-off effect by the pressure, the reduction of the moisture content of the adhered pulverized coal is promoted by heat, and as a result, the adherence of the pulverized coal is reduced.

Further, in the solution means (2), by heating a pipe heater, a micro-heater, etc., the surface temperature of these is maintained at a certain temperature or higher, and the moisture content of the pulverized coal which is in contact with these surfaces is reduced. Is promoted, and as a result, the action of reducing the adhesive force of pulverized coal occurs. Further, it is possible to scrape off pulverized coal attached to the inner wall of the coal feeding pipe and suppress the attachment.

Further, in the solving means (3) and (4),
By heating the heater provided in the outer cylinder that surrounds the outside of the coal feeding pipe, or by supplying heated gas to the space of the annular cross section formed between the outer surface of the coal feeding pipe and the outer casing, Heat the outer surface of the coal feeding pipe. Then, the internal temperature of the inner surface of the coal feeding pipe rises due to heat conduction and is maintained at a certain temperature or higher. As a result, the reduction of the moisture content of the pulverized coal that is in contact with the scraper surface is promoted, and the adhesive force of the pulverized coal is reduced.

[0012]

1 (a) and 1 (b) are longitudinal side views showing a scraper tube in a first embodiment of the present invention. In these drawings, 12 is a scraper pipe, 13 is a plurality of through holes (blowing holes) provided in the pipe wall of the scraper pipe 12,
Reference numeral 14 is a heated gas inlet pipe, 15 is a solenoid valve, and 16 is a timer.

In FIG. 1A, hot air (heating air or heating gas) 17 having a predetermined pressure and temperature is sent to the inside of the scraper pipe 12 through a heating gas inlet pipe 14 and provided on the pipe wall of the scraper pipe 12. This is a system in which hot air is continuously blown out from the through hole (blowing hole) 13. 1 (b) is also hot air 1
7 is supplied in the same manner as in FIG. 1A, and the solenoid valve 15 and the timer 1 are supplied.
It is a method of intermittently blowing out from the blowout hole 13 by the combination of 6. In either method, in addition to the effect of blowing off by pressure, the reduction of the moisture content of the adhered coal by heat is promoted, and as a result, the adherence of the coal is reduced and growth on the scraper surface and coal feeding pipe is prevented. The effect will occur. As the hot air used in this example, exhaust gas, heated steam, or the like can be used as appropriate.

Next, FIG. 2 shows a second embodiment of the present invention. FIG. 2 (a) is a plan view and FIG. 2 (b) is a vertical side view. In the figure, 21 is a coal feeding pipe, 22 is a pipe heater type scraper, 23 is a claw, and 24 is a hopper.

In this embodiment, instead of the conventional scraper,
The pipe heater or the micro heater is used as a scraper to raise the scraper surface temperature to a predetermined temperature. In this method, if the surface temperature of the scraper 22 is maintained at a predetermined temperature, the high-moisture pulverized coal falling inside the coal feeding pipe 21 comes into contact with the surface of the scraper 22 to reduce the moisture, and The adhesion function of is reduced. Further, also on the inner wall surface of the coal feeding pipe 21, the adhering function of the pulverized coal is lowered due to the influence of the scraper 22. Even if it adheres, it can be scraped off by the original function of the scraper.

Next, FIG. 3 is a vertical sectional side view showing a third embodiment of the present invention. In this embodiment, an outer cylinder 32 is installed coaxially around the outside of the coal feeding pipe 31, a heat insulating material 33 is applied, and
A heating wire 35 is wound around the outer cylinder 32 to heat the outer cylinder 32,
The radiant heat raises the surface temperature of the coal feeding pipe 31 to a predetermined temperature. If the surface temperature of the coal feeding pipe 31 is maintained at a predetermined temperature in this way, the pulverized coal having a large amount of moisture falling inside the coal feeding pipe 31 comes into contact with the inner wall surface of the pipe, the moisture is reduced, and the adhesion function of the pulverized coal is deteriorated. .. In the present embodiment, no scraper is required and the coal feeding pipe is not required to rotate.

Next, FIG. 4 is a vertical sectional side view showing a fourth embodiment of the present invention. In this embodiment, a coaxial outer cylinder 42 and a heat insulating material 43 are provided so as to surround the coal feeding pipe 41, and the outer cylinder 42 is provided.
By circulating hot air (exhaust gas or heated steam) 44 in the space of the annular cross section formed between the coal feeding pipe 41 and the coal feeding pipe 41, the surface temperature of the coal feeding pipe 41 is set to a predetermined temperature as in the third embodiment. The moisture content of pulverized coal falling in the pipe is reduced to prevent the adherence. This embodiment can also be applied regardless of whether the coal feeding pipe is rotated or not, and does not require a scraper.

In each of the above examples, the pulverized coal is heated and dehumidified inside the coal feeding pipe. However, if the coal left in the coal storage yard is simply transported in the order of the bucket elevator, the coal bunker, and the belt conveyor and supplied to the coal feeding pipes of these examples, in the case of pulverized coal containing a particularly large amount of moisture, the coal feeding is still performed. May adhere to the surface of pipes and scrapers. In such a case, for example, the coal pretreatment is performed by using a coal feed pipe upstream heating type conveying device as shown in FIG.

In FIG. 5, reference numeral 51 is a bucket conveyor for lifting the coal 58 carried from the coal storage yard to the coal bunker 54 at a high place, and it is rising slowly. Utilizing this time, hot air is blown from the hot air jet pipe 52 to dry the coal in the bucket conveyor 51. This coal exits with hot air from the coal outlet 53 and falls on the upper part of the coal bunker 54. The falling coal and the rising air stream of the hot air blown out from the hot air jet pipe 55 are crossed to further dry the coal. The dried coal drops in the bunker 54 and is deposited and conveyed on the belt conveyor 56. The hot air jet pipe 57 is installed in the center of the belt conveyor 56, and the hot air from the hot air jet pipe 57 passes through the belt conveyor 56 made of mesh material to deposit the coal 5
Dry 9. Then, the sufficiently dried coal 59 falls into the subsequent coal feeding pipe.

As described above, when the bucket conveyor 51, the coal bunker 54, and the belt conveyor 56 are provided with hot air ventilation means, respectively, the supplied coal is heated, and if the surface moisture of the coal is reduced, the subsequent supply is reduced. Adhesion of pulverized coal on the coal pipe is reduced.

[0021]

According to the present invention, the following effects can be obtained. 1) Since the temperature of the inner wall of the coal feeding pipe and the surface of the scraper is maintained at a certain temperature or higher, the adhesive force of the pulverized coal is reduced, and the pulverized coal falling inside the coal feeding pipe does not adhere even if it contacts the inner wall of the coal feeding pipe and the scraper. .. Therefore, the coal feeding pipe is unlikely to be blocked even if the pulverized coal to be charged contains a large amount of moisture. 2) Therefore, the inner diameter of the coal feeding pipe can be small, and the entire coal feeding pipe can be made compact. 3) It becomes easy to control the moisture content and the particle size of the pulverized coal to be charged.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a scraper tube according to a first embodiment of the present invention.

FIG. 2 is a plan view and a vertical sectional side view showing a second embodiment of the present invention.

FIG. 3 is a vertical cross-sectional side view showing a third embodiment of the present invention.

FIG. 4 is a vertical sectional side view showing a fourth embodiment of the present invention.

FIG. 5 is a conceptual diagram illustrating a coal pretreatment device used in each of the above embodiments.

FIG. 6 is a vertical sectional side view showing an example of a conventional coal feeding pipe.

7 is an enlarged horizontal cross-sectional view of FIG.

[Explanation of symbols]

 1 Coal feeding pipe 2 Scraper 3 Claw 4 Hopper 5 Mill (fine coal pulverizer) 6 Conveyor 7 Motor 8 Speed reducer 9,10 Pulverized coal 12 Scraper pipe 13 Through hole (blowing hole) 14 Heating gas inlet pipe 15 Solenoid valve 16 Timer 17 Heated gas (hot air) 21 Coal supply pipe 22 Pipe heater type scraper 23 Claw 24 Hopper 31 Coal supply pipe 32 Outer cylinder 33 Heat insulation material 35 Electric heating wire 41 Carbon supply pipe 42 Outer cylinder 43 Heat insulation material 44 Hot air 51 Bucket conveyor 52 Hot air jet pipe 53 Coal outlet 54 Coal bunker 55 Hot air jet pipe 56 Belt conveyor 57 Hot air jet pipe 58,59 Coal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaken Yamauchi 1-1-1, Niihama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Research Institute (72) Inventor Koichi Takenobu 1-chome, Wadazaki-cho, Hyogo-ku, Kobe 1-1 No. 1 Sanryo Heavy Industries Co., Ltd.Kobe Shipyard (72) Inventor Takeo Araki 1-1-1 Wadazakicho, Hyogo-ku, Kobe Sanryo Heavy Industry Co., Ltd. Kobe Shipyard (72) Inventor Tomonori Hirota Kobe City Hyogo 1-1-1 Wadasaki-cho, Tokyo Sanryo Heavy Industries Ltd. Kobe Shipyard

Claims (4)

[Claims] 1. A coal feed pipe for supplying coal to a coal-fired boiler mill is configured to be vertical and rotatable about an axis, and a stationary scraper pipe having a plurality of through holes in a pipe wall is the coal feed pipe. And a means for supplying heated gas to the scraper pipe, the coal feed pipe blockage prevention device. 2. A coal feeding pipe for supplying coal to a coal burning boiler mill is configured to be vertical and rotatable about an axis, and a pipe heater or a micro heater is inserted as a scraper into the coal feeding pipe. Characteristic coal feed pipe blockage prevention device. 3. A coal feed pipe blockage prevention, characterized in that a coaxial feed pipe is provided around a feed pipe for supplying coal to a coal burning boiler mill, and a heating wire is attached to the feed pipe. apparatus. 4. A coaxial outer cylinder is provided so as to surround a coal feeding pipe for supplying coal to a coal burning boiler mill, and a space having an annular cross section formed between the outer casing and the coal feeding pipe. A coal feed pipe blockage prevention device comprising means for supplying heated gas.