JPS63224744A - Method of crushing massive material - 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 Field of the Invention The present invention relates to a method for crushing lumps applied to a roller mill for crushing coal in a pulverized coal-fired boiler.

However, the present invention is not limited to this, and can also be applied to a cement mill that crushes talin car and the like.

2. Description of the Related Art There is a conventional method of pulverizing lumps of coal or the like used in pulverized coal-fired boilers, as shown in FIG.

An example of an apparatus for crushing lumps such as coal into fine powder is Roller Mill I.

In this roller mill, lumps (not shown) are fed from a lump supply pipe 2 provided at the top of the mill, and are continuously fed into a (rotary) table 3 placed inside the mill. The lumps are crushed by the plurality of pulls 3 and the plurality of rollers 4 which rotate while being pressed against the upper surface of the table, and are further blown to the outer periphery of the rotary table 3.

Further, a carrier gas supply port 6 is provided in the side portion 5 of the roller mill 1 for supplying a preheating gas, that is, a carrier gas (not shown) for drying (preheating) the particles formed by crushing the agglomerates.
The particles are fed into the mill 1 from the roller mill 1 and further passed through the blower part 7 provided around the rotary table 3, whereby the particles are blown into the second part of the roller mill 1. In this way, the particles carried by the carrier gas are fed into the classifier 8 disposed at the upper part of the mill, and the particles are further classified into coarse powder and fine powder inside this classifier. After this,
The former coarse powder falls along the inner wall of the funnel-shaped cone 9 at the bottom of the classifier 8, is scattered on the table 3, and is crushed again. On the other hand, the latter fine powder, which becomes a product, is discharged (taken out) to the outside from a plurality of particle discharge pipes 10 arranged around the lump supply pipe 2 while being conveyed by a carrier gas.

The particle size of the finished fine powder is sorted by adjusting the fine powder entrance angle (exit angle) of a guide vane 12 provided between the cone 9 and the inner cylinder 11 in the upper part of the classifier 8. This angle is adjusted by an angle adjuster 13 provided on the outside upper part of the roller mill 1.

Problems to be Solved by the Invention The conventional method for crushing agglomerates described above, however, has the problems shown in FIG. 3.

Particles of crushed agglomerates, namely coarse powder 14 and fine powder 15
has a tendency to aggregate, and this is due to the fact that the new surface created by pulverization becomes electrically activated, the surface area increases, and the fine powder itself has adhesive properties. There is.

As shown in FIG. 3, when the fine powder 15 is aggregated with the coarse powder 14, the fine powder 15, which should originally be taken out as a product, is re-pulverized together with the coarse powder 14. This leads to over-pulverization, leading to an increase in the consumption of crushing power (not shown).

Moreover, when a so-called coating phenomenon occurs in which a large number of fine powders 15 cover the coarse powder I4, the crushing load applied between the (rotary) table and the crushing roller is dispersed, and the crushability of the coarse powder 14 becomes worse. Put it away.

As described above, when the coarse powder 14 and the fine powder 15 agglomerate, serious problems arise such as an increase in the crushing power and a decrease in the crushability.

Means for Solving the Problems In order to solve these conventional problems, the present invention provides the following:
The agglomerates are fed onto a rotating table, the agglomerates are pulverized by a crushing roller that rotates while being pressed against the table, and the pulverized particles are discharged by a carrier gas blown up from around the table. In the grinding method, the surface of the above particles? This material was discharged after adsorbing a dispersant to reduce the cohesive force.

According to this method, a dispersant that reduces the cohesive force of the particles of the crushed agglomerates is mixed into the carrier gas or sprayed directly onto the powder in a roller mill, so that the particles to be crushed are The dispersing material can be sufficiently adsorbed on the surface, and then the dispersed particles can be reliably discharged from the roller mill.

Embodiment An embodiment of the present invention will be described in detail below with reference to FIG. In FIG. 1, the same parts as those shown in FIG. 2 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

According to the present invention, in the method for crushing agglomerates as described above, dispersion nozzles 16 for dispersing material (not shown) are provided inside the roller mill 1 at the side portions 5 and/or the roller mill 1.
Alternatively, it is attached to the carrier gas supply port 6 and/or the classifier 8, etc. A plurality of these nozzles are arranged at appropriate angles in the circumferential direction at respective positions.

By using these spraying nozzles 16 alone or in combination, a dispersing material is sprayed from these spraying nozzles 16 onto the surface of the particles of the agglomerates to be crushed to reduce their cohesive force. Ru.

Furthermore, among these nozzles, the side 5 of the roller mill I
and/or in the case of the nozzle 16 located at the carrier gas supply port 6, the dispersion material is carried on the carrier gas and dispersed,
While being mixed in the gas phase, it will be adsorbed onto the particle surfaces as described above. On the other hand, in the case of the nozzle 16 located in the classifier 8, the dispersing material is directly sprayed onto the particles falling along the inner wall of the cone 9, and is similarly adsorbed onto the particle surface. However, especially when dispersing the dispersion material from the nozzle 16 of the carrier gas supply port 6, the carrier gas flowing into the supply port 6 is preheated and is usually in a high temperature atmosphere of 100°C or more, so it is not likely to be thermally destroyed. It is necessary to select a dispersing material that will not cause

The types of dispersants include, for example, Rheosdart MPF, a trade name manufactured by Lion Corporation. Before use, this dispersant is in a solid state, but when used, it is turned into a liquid state and mixed into the carrier gas or It is sprayed directly onto particles. In addition, the amount of dispersion per use is approximately 0.05% by weight.
That's about it.

By the method described above, the above-mentioned dispersion material can be sufficiently adsorbed on the surface of the particles of the lumps crushed by the table 3 and the crushing roller 4.

After this, the particles that have been reliably dispersed no longer have cohesive forces acting on each other, and therefore particles (fine powder) of the desired particle size are released from the particle discharge pipe 10 of the roller mill 1. can be discharged stably.

Table 1 shows an example of the present invention in which the operating conditions of the roller mill 1, such as the amount of coal supplied and the amount of preheated air, were kept constant.

Table 1 It can be seen that this is significantly reduced compared to the method using the above method.

Effects of the Invention As detailed above, according to the present invention, due to the dispersion treatment effect of the dispersion material on the particles of the crushed agglomerates, mutual aggregation of the particles can be reliably prevented (first
(see table), the occurrence of over-grinding can therefore be considerably reduced, and as a result the consumption of the grinding power can be kept to a minimum. According to experiments, it has become possible to actually reduce the crushing power by as much as 30%.

Furthermore, since the coating phenomenon of coarse powder with fine powder can be sufficiently eliminated, the crushing load applied between the (rotary) table and the crushing roller can be concentrated, and as a result, the crushability of coarse powder is improved. can be made quite good. Moreover, it shortens the time of the crushing process,
Moreover, costs can be reduced along with the above-mentioned energy saving.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing an example of the method for crushing a lump according to the present invention, FIG. 2 is a cross-sectional view of a main part showing a conventional method for crushing a lump, and FIG. FIG. 2 is a diagram showing the adsorption state of particles, that is, coarse powder and fine powder. 1. Roller mill, 3. (rotating) table, 4.
Grinding roller, 14.15... Particles (coarse powder and fine powder (other 1
Name) Figure 1 4: Loaf Mishi 3: Chi 71 Shi 4: Early roller in half 74.15: Hashiri Tatej door (4th eye, coming power l toq, igibun, child) 161 Scattered nosuru Figure 2

Claims (1)

[Claims] A grinding method in which a lump is supplied onto a rotating table, the lump is pulverized by a grinding roller that rotates while being pressed against the table, and the pulverized particles are discharged by a carrier gas blown up from around the table. A method for crushing agglomerates, characterized in that a dispersant for reducing cohesive force is adsorbed onto the surface of the particles and then discharged.