JPS5820247A - Detection of ignition in mill - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the following method:
In particular, this is a method for detecting ignition in a pyrite box to prevent a fire from occurring in a pyrite box due to coal contained in pyrite (foreign matter) mixed in coal.

In Japan, due to the tight supply of heavy oil, in order to correct the dependence on heavy oil, we are converting the fuel from the conventional heavy oil-burning to coal-burning, especially for business use.
Due to the enormous consumption of coal, large-capacity thermal power plants that burn coal exclusively are being constructed.

Since coal fuel has poor combustibility compared to heavy oil fuel, coal is pulverized into pulverized coal using a paddle mill such as a pole mill, a four-larch mill, or a chape mill in order to improve its combustibility. It contained a large amount of unpulverized metals and rock-like foreign matter (hereinafter referred to as pyrite), and this pyrite was mostly Hiro coal that had been dumped for 4 hours.

However, from the point of view of reducing the volume of pyrite itself and saving energy, this pyrite is re-crushed, the long coal produced from within the pyrite is extracted, the pulverized coal is reused as fuel, and the amount of pyrite F that is discarded is reduced. There is a tendency to decrease.

The present invention has arrived at this point, and its purpose is to store the coal in the pyrite box where the pyrite tube is stored!
The objective is to obtain a method for detecting ignition in a mill that can detect ignition of flammable gas generated from this coal and prevent fires and explosions in the colander. .

In short, the present invention detects flammable gas pipes such as methane, ethane, and CO generated from pyrite in a pyrite box to identify whether ignition is occurring or not.

The ball mill 1 is composed of a coal feed pipe 2, a coal crushing section 3, a power transmission section 4, a classifier 5, a pulverized coal outlet pipe 6, and a pyrite discharge lower.

The coal crushing section 8 is formed by a lower ring 8 connected to the power transmission section 4 and rotating at a constant rate, on which a plurality of balls 9 that revolve and rotate on their own are placed, and an upper ring 10 fixed in this manner. ing.

Coal is supplied from the upper part of the coal feed pipe 2 located at the center of the ball mill 10, as shown by the arrow, to the inside of the coal crushing section 30, as shown by the arrow B''r''. In this coal crushing w3, the coal is crushed by the lower ring 8 and the balls 9, and after being delivered to the outside of the coal crushing section 3 as shown by the arrow C, the crushed coal is transported by the conveying air as shown by the arrow. It is blown up inside the ball mill l and sent into classification j5 as shown by arrow E.

The right side of the coal sent into the classifier 5 is separated into pulverized coal and coarse pulverized coal.The pulverized coal goes from the outlet pipe 6 of the classifier 5 to a burner (not shown) as shown by the arrow F, and the coarse pulverized coal goes to the burner (not shown) as shown by the arrow G. As shown by the arrow B, by specific gravity separation, the coal is recirculated from the bottom of the classifier 5 to the inside of the coal crushing section 30 as shown by arrow B and is crushed into pulverized coal.On the other hand, the pyrite contained in the coal is crushed into coal. Since the coal is not completely crushed even after passing through the coal crushing section 3, it is separated from the crushed coal by specific gravity separation outside the coal crushing section 3, and the gap between the relief gate 11 and the lower ring 8,
(a-) falls from the gap 12 onto the bottom plate 13 as shown by the arrow H, is attached to the rotating upper l-l 14 and is collected by the nine pushers 15; After 17 sessions of the light box, it is discharged from the pyrite discharge lower.

The above is an explanation of the general flow of coal and pyrite in the bottle in the mail IK.In the past, pyrite is stored in a fixed amount in the pyrite box 17. After the pyrite is removed, it is taken out from the pyrite outlet γ and thrown away for use in the field.However, since the pyrite contains edible coal, it is not desirable from the point of view of energy saving, and the pyrite is b) From the viewpoint of zero sterilization, there is a tendency to recirculate the pyrite containing the coal branch pipe to the coal crushing section 3 using the feeder 22, etc., and reuse the coal content of the pyrite), such a reuse method. In this case, since the atmospheric temperature inside the pyrite box 17 is high, flammable gas is generated from the coal in the pyrite, and there is a high risk of ignition. The detection means 23 provided detects the flammable gas of pyrite, and the detected combustible gas is guided to the gas detector 524 to identify whether or not the combustible gas is ignited. In other words, if the amount of pyrite in the pyrite box 17 is less than the specified amount, the pigeon loft 18 will be opened and the exit logger will be activated. )
19Fi is closed and the gallery building 1 is operated with the feeder 22 stopped.

On the other hand, since the amount of pyrite reaches the amount of pyrite box 1, the inlet gate 18 is closed and the outlet gate 19 is opened. On the other hand, illite that does not pass through the screen 21 is discharged from the pyrite discharge lower.

In this way, illite is temporarily stored in the pyrite box 17, and there is a risk that the pyrite will ignite when the ambient temperature in the pyrite box 17 is high.
If the coal is recirculated to the coal crushing section 3 in the ball mill 1, it will help to cause a fire pipe in the ball mill 1.

Therefore, as mentioned above, pyrite is methane, ethane, C
The amount of combustible gas generated is 501'Pm at 50@C and 110'Pm at 10G''C.
0pp, 2.500ppm at 230'C 11 degrees is generated, so this flammable gas is removed from the pyrite box 1.
The combustible gas is collected by a detection means (collection nozzle) 23 provided in the gas detector 7, and is guided to a gas detector 24 to identify whether the combustible gas is ignited or not, and sends a detection signal 26 to an alarm generator 25. Since K is set to transmit, fires and explosions can be detected in advance based on the amount of combustible gas in the pyrite box 17.

According to the present invention, since combustible gas can be identified based on the amount of gas, safer operation is possible, and there are also advantages in reducing the volume of pyrite and reusing pyrite.

[Brief explanation of drawings]

The drawing is a schematic diagram of a ball mill showing an embodiment of the present invention. 1...Ga-ru building, 2...Coal feed pipe, 3
...Coal crushing section, 17...Pyrite box, 22...Fida, 23------...
Detection means, 24... Gas detector, 25...
...Alarm generator, 26...Detection signal.

Claims (1)

[Claims] Coal 11 is fed from the coal feed pipe to the coal crusher 11, and in this coal crusher it is separated into pulverized coal and foreign matter contained in the coal pipe.The pulverized coal is sent to the outlet pipe, and the foreign matter is transferred to the coal crusher. In the device that is recirculated to the foreign object, a detection means provided in the foreign object duct detects the foreign object's combustible gas and gas, and the detected combustible gas is guided to a gas detector to identify whether or not there is ignition. Nine things! Method for detecting ignition inside the mill for special features @