JP2655875B2 - Crusher - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverizing apparatus for pulverizing a solid raw material, and more particularly to a pulverizing apparatus capable of early detection of clogging of a raw material in a supply pipe section of an input raw material.

[Conventional technology]

A method for detecting clogging of a raw material supply pipe in a conventional pulverizer will be described with reference to a vertical pulverizer shown in FIG. 4 as an example.

Raw coal 10 sent from a coal feeder (not shown)
It is put into a coal feed pipe 2 provided at the center of the pulverized coal machine 1, and is put between a disc-shaped lower ring 5 and an upper crushing ring 6 which are driven and rotated via an electric motor 3 and a speed reducer 4. Is pulverized by a pulverizing ball 7 which is sandwiched between and rotated.
The pulverized coal 10 is roughly classified into fine powder 10a and coarse powder 10b by hot air 20 for drying and transporting from the air chamber 8 below the lower ring, and the fine powder 10a is provided at the top of the pulverizer. The fine powder 10c is further classified into fine powder 10c and fine powder 10d by the classifier 9, and the fine powder 10c returns to the center of the lower ring again through the burner of the combustion device, passes through the chute, and is crushed again.

In such a pulverizing device, the above coarse powder is provided above the gap 21 for drying air provided outside the lower ring.
10b and the fine powder 10d are always in a floating state by the drying air, forming a fluidized bed. In this fluidized bed, the thickness of the bed changes substantially in proportion to the increase or decrease in the amount of raw coal supplied.

In the conventional apparatus, pressure detecting seats 11 and 12 are provided at the air inlet 22 and the classifier inlet 23 of the pulverizer, respectively, so as to obtain a pressure difference when air passes through the fluidized bed.
The fine powder in the raw coal is deposited and deposited in the coal feed pipe 2 to cause clogging, the amount of coal supplied to the pulverizer decreases, and when the fluidized bed becomes thinner, the pressure difference decreases. This detects the blockage of the coal pipe. The differential pressure in the normal operation range is as wide as 300 to 750 mmAq, and the detection set value of the low differential pressure is 100 to 150 mmAq.

[Problems to be solved by the invention]

In the above prior art, since the clogging condition is detected by detecting a change in the pressure difference between the upper and lower sides of the fluidized bed of the material to be crushed, the coal feed pipe is almost blocked, and the supply of raw coal is reduced. It was a situation where blockage was discovered only when the condition was close to stopping. As a result, a time loss occurs until the clogging is detected. At the time of detection, the raw coal is clogged in the coal feed pipe, and the pulverizer must be stopped to clean the feed pipe. There was a problem that became impossible. Further, a method of constantly flowing water inside the coal feed pipe to prevent adhesion is also implemented, but this is a method contradicting the purpose of drying and pulverizing coal in a pulverizer.

An object of the present invention is to continuously operate the pulverizer without the above-mentioned problem by detecting the adhesion at the time when the raw material starts to adhere to the inside of the coal feed pipe and cleaning the inside of the coal feed pipe early.

[Means for solving the problem]

The above-mentioned problems of the prior art include a pulverizing unit for pulverizing a solid raw material, a raw material supply pipe for supplying the solid raw material to be pulverized to the pulverizing unit, and a discharge unit for conveying the fine powder of the pulverized raw material to the outside. In the pulverizing device provided with: an air hole opened in the tube wall of the raw material supply pipe, an air chamber provided outside the raw material supply pipe and surrounding the air hole, and supplying air to the air chamber. A pulverizing device, comprising: an air line to be closed; and a blockage detection device that detects a blockage state of the raw material supply tube by an amount of air supplied to the air chamber through the air line and / or air pressure. Is done.

〔Example〕

A specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a pulverizing apparatus provided with a coal feeding pipe with an adhesion detecting device according to the present invention. 2 and 3 are enlarged detailed views of the detection device.

1 and 2, the pulverized coal machine 1 has an upper crushing ring 6, a lower crushing ring 5, a crushing ball 7, and a coal supply pipe 2. Coal is supplied from the coal supply pipe 2, and
Crushed. The pulverized coal 10 is dried and classified by hot air for drying and transporting from an air chamber below the lower ring 5, and the fine powder is classified at a temperature of about 80 ° C. in a classifier 9 provided at the upper part of the pulverizer. Further fine powder 10c and fine powder 1
Classified as 0d, fine powder 10c goes to burner, fine powder 10d shoots
After passing through 25 again, it returns to the center of the lower ring 5 and is crushed again. The adhesion detecting device is provided outside the coal feed pipe 2. The detection device includes an air chamber (air chamber) 13, an air pipe 14,
A plurality of air holes 18 are provided around the pipe wall of the pressure gauge 15, the pressure regulating valve 16, the flow meter 17 with a contact point, and the coal feed pipe 2.

The air sent to the adhesion detecting device is sent into the pulverized coal machine through the air holes 18. The internal pressure of the pulverized coal machine 1 is only a ventilation resistance from the pulverized coal machine 1 to the burner, and is a substantially constant pressure. Therefore, a certain amount of air flows into the pulverizer during normal operation, but the flow rate changes due to coal fines adhering to the inside of the coal supply pipe and blocking several places of the air port. Further, it is possible to detect the adhesion before reaching the internal blockage of the coal feed pipe.

Accordingly, by continuously cleaning the inside of the coal feed pipe with a cleaning device, for example, a pipe cleaner or the like at an early stage by detecting the adhesion, continuous stable operation is possible.

FIG. 3 is a sectional view taken along line II in FIG.
The situation where an air hole is provided around the pipe wall of the coal feed pipe 2 is shown. If the pulverized coal adheres to the inner surface of the coal feed pipe and the air hole is closed, the pressure of the air pipe 14 increases. Therefore, the change in the pressure indicated by the pressure gauge 15 can detect the blockage. Since the blockage starts to occur near the lower end of the coal feed pipe,
The air hole for detecting blockage is desirably provided in a lower portion of the coal feed pipe.

〔The invention's effect〕

According to the present invention, when the raw material starts to adhere to the inside of the raw material supply pipe, the adhesion can be detected, so that there is an effect that a countermeasure can be taken at an early stage before the supply pipe is clogged.

[Brief description of the drawings]

FIG. 1 is a side view showing a pulverizing device provided with a coal feed pipe blockage detecting device according to the present invention, FIG. 2 is a partially enlarged view of the detecting device of FIG. 1, and FIG. FIG. 4 is a side view of a conventional crushing apparatus, taken along a line II in FIG. 1 ... pulverized coal machine, 2 ... coal feed pipe, 5 ... lower crushing ring, 6 ... upper crushing ring, 7 ... crushing ball, 9 ...
Classifier, 10: Coal raw material, 13: Air chamber, 14: Air tube, 15: Pressure gauge, 16: Pressure regulating valve, 17: Flow meter with contacts, 18: Air hole.

Claims (1)

(57) [Claims] A crushing section for crushing the solid raw material, a raw material supply pipe for supplying the solid raw material to be crushed to the crushing section, and a discharge section for conveying fine powder of the crushed raw material to the outside. In the pulverizer, an air hole opened in a tube wall of the raw material supply pipe, an air chamber provided outside the raw material supply pipe and surrounding the air hole, and an air pipe for supplying air to the air chamber A pulverization device comprising: a blockage detection device configured to detect a blockage state of the raw material supply pipe based on an amount of air supplied to an air chamber via an air pipe and / or air pressure.