JPS63116750A - Production unit for coal-water slurry - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coal-water slurry manufacturing device, and particularly relates to a coal-water slurry manufacturing device, and particularly to a device for producing coal-water slurry, which includes a lower ring that is rotatably installed, and an upper ring that is placed above the lower ring. The present invention relates to a coal-water slurry manufacturing apparatus suitable for reducing coal crushing power in a ring roller mill that wet-compresses and crushes coal between the ring and the balls by disposing a ball therebetween.

[Conventional technology]

Coal-water slurries are being developed to improve the handling of coal, which is a solid fuel.

Coal-water slurry is composed of coal, water, and a small amount of surfactant, and is generally produced by pulverizing coal using a wet mill.

A wet tube mill has already been proposed as a device for producing coal-water slurry, but the inventors believe that it requires less power to crush the coal and less water to make the slurry have the desired fluidity. We proposed a coal-water slurry manufacturing device using a ring roller mill with special features (patent application filed in 1973).
9-203761, etc.). In coal-water slurry production equipment using ring roller mills, it is difficult to control the residence time of coal particles in the crushing section of the mill, so a portion of the slurry coming out of the mill is passed through a distributor to the mill. need to be returned to.

FIG. 3 is a system diagram of a conventional coal-water slurry manufacturing apparatus using a ring roller mill. In Figure 3, bunker 1
The coal A in the interior is fed through the feeder 2 and from the coal feed pipe 4 at the top of the wet vertical ring roller mill 3, as well as water B and surfactant liquid C.
and pHl adjustment liquid are injected into the mill from tanks 5.6 and 7, respectively, via coal feed pipe 4 by pumps 8.9 and 10, respectively. The mixture of coal, water and additives pulverized in the ring roller mill 3 is sent from the outlet 11 at the bottom of the mill to the slurry distributor 13 by the slurry pump 12, and a part of it is sent into the mill from the coal feed pipe 4 of the mill. It is circulated. The remaining slurry distributed by the distributor 13 is sent to the coarse grain separator 14 installed above the mill, and the separated coarse grains are recycled into the mill 3 from the coal feed pipe 4 of the mill by gravity. .

The coal-water slurry that has passed through the coarse separator 14 is stored as a product in a slurry pump 15.

FIG. 4 is a sectional view of the ring roller mill in FIG. 3. In FIG. 4, the crushing section includes a crushing table 17,
The upper fixed ring (
an upper ring) 19; a lower roller (lower ring) 21 installed at the end of the crushing table 17 rotated by a drive device 20; It is composed of a plurality of grinding balls 22 that roll with rotation, and a scraper 23 for cleaning the inside of the coal feed pipe that is installed eccentrically from the center of the grinding table 17. Coal A to be wet-pulverized is sent to distributor 1
3 (See Figure 3) Circulating slurry from coarse separator 14
It is supplied to the coal feed pipe 4 of the pulverizer main body 16 together with the coarse particle slurry, water, surfactant liquid, and pH adjuster liquid from the pulverizer main body 16 (see FIG. 3).

The mixture of coal, water, and additives supplied to the coal feed pipe 4 falls through the coal feed pipe 4, but the mixture adhering to the inner surface of the coal feed pipe 4 is removed by the cleaning scraper 23 that rotates together with the crushing table 17.
The particles are scraped and dispersed on the grinding table 17. The mixture of coal, water and additives dispersed on the grinding table 17 is moved to the grinding ball arrangement part by the centrifugal force generated by the rotation of the grinding table 17, and a pressure Ii? is generated between the balls 22 and the lower ring 21. i! Shattered. The crushed coal flows down from the space between the lower ring 21 and the crusher main body 16 into the slurry weir 24 below the crushing table 17, and is mixed by the mixing seed 25 installed at the bottom of the rotating crushing table 17. It is discharged from the discharge port 11.

[Problem that the invention seeks to solve]

In the above-described coal-water slurry manufacturing apparatus, the ratio of the weight of the slurry returning to the ring roller mill 3 to the amount of slurry entering the distributor 13 (hereinafter referred to as distribution ratio) is 0, although it varies depending on the coal and the pulverization conditions. .90 to 0.99, and the amount of slurry circulated to the mill is the coarse separator 14.
This is 10 to 100 times the amount of slurry sent to the factory. For this reason, there was a problem that the distributor 13 became large and the circulation pump for circulating the slurry between the distributor 13 and the ring roller mill 3 became large and the pump power increased.

The purpose of the present invention is to solve the problems of the prior art described above,
It is an object of the present invention to provide a coal-water slurry manufacturing apparatus that can control the residence time of coal particles in a mill without increasing the crushing power, and can downsize a distributor, circulation pump, etc.

[Problem that the invention seeks to solve]

The above purpose is to place a ball between a rotatably installed lower ring and an upper ring installed above the lower ring, and compress and grind the coal between the ring and the ball under wet conditions. This is achieved by providing an upper ring within the ring roller mill that is rotatable in a direction opposite to the direction of rotation of the lower ring.

[Effect]

The coal particles in the slurry are compressed and ground between the ball and the lower ring. The slurry that has fallen onto the grinding table is moved to the lower ring by the centrifugal force that accompanies the rotation of the grinding table. The moving speed of the slurry moving toward the lower ring varies depending on the rotation speed of the lower ring, and the residence time in the crushing section can be controlled by this rotation speed. However, if the rotation speed of the lower ring is lowered, the moving speed of the balls will also be lowered, and the crushing capacity will be reduced. At this time, if the upper ring is rotated in the opposite direction to the rotational direction of the lower ring, the residence time of the coal particles in the crushing section can be maintained for a predetermined time, and at the same time, a decrease in crushing capacity can be prevented.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings. 1st
The figure is a sectional view of a ring roller mill provided in the coal-water slurry manufacturing apparatus according to the present invention, and FIG. 2 is a system diagram of the coal-water slurry manufacturing apparatus equipped with the ring roller mill shown in FIG. 1.

1 and 2, the difference from the conventional device shown in FIGS. 3 and 4 is that a drive device 26 is provided for rotating the upper ring 19 in a direction opposite to the direction of rotation of the lower ring 21. A slurry flow meter 283 is installed in the middle of the line that circulates the slurry from the mill 3 to the distributor 13, and a slurry flow meter 283 is installed in the middle of the line that circulates the slurry from the mill 3 to the distributor 13. 6. A mixing tank 27 is provided in which the water, surfactant liquid, and pH adjuster liquid from 7, the slurry from the distributor 13, and the slurry from the coarse particle separator 14 are mixed and stored. A slurry flow meter 28b is installed in the middle of the line for introducing slurry into the coal feed pipe 4 of the mill 3.

The detection signals from the slurry flowmeter 283 and the slurry flowmeter 28b are input to a controller (not particularly shown), and the rotation speed of the drive device 20 that rotates the lower ring 21 is controlled based on the control signal from this controller. It is supposed to be done.

The distributor 13 may be a branch pipe equipped with a flow rate adjustment valve, but any type of device may be used as long as it can distribute the coal particles as they are without classifying them. The coarse particle separator 14 may be of any type, such as a strainer, wet screen, sieve bend, etc., as long as it can separate particles of about 300 to 1000 μm or more in the slurry.

In FIGS. 1 and 2, components other than those described above are the same as those in FIGS. 3 and 4, so they are designated by the same reference numerals and a detailed explanation of the construction will be omitted.

Next, the operation of the coal-water slurry manufacturing apparatus configured as described above will be explained.

Upper ring 19 force 1 movement device 26 lower ring 2
Rotate in the opposite direction to 1. From coal feed pipe 4 to powder table 1
The slurry (a mixture of coal, water, surfactant, circulating slurry, and coarse slurry) that fell onto the grinding table 17
It moves to the lower ring 21 due to the centrifugal force generated by the rotation of the ball 22 and is compressed and ground between the balls 22 and the lower ring 21. The slurry containing the crushed coal falls from the space between the end of the lower ring 21 and the crushing body 16 into the slurry weir 24 below the crushing table 17, and is mixed by a mixing device [25] installed at the bottom of the rotating crushing table 17. Exhaust port 1
It is discharged from 1.

During such pressure crushing of coal, if the rotation speed of the lower ring 21 is lowered, the residence time of the coal particles in the crushing section becomes longer, and the degree of crushing (
For example, the increase in the amount of mesh passing through 200 meshes increases.

However, if the rotational speed of the lower ring 21 is too low, the slurry cannot be smoothly discharged to the outside of the mill, resulting in a reduction in crushing capacity, and furthermore, the inside of the mill may become clogged.

In this embodiment, from the mixing tank 27 to the coal feed pipe 4 of the mill 3,
The flow rate s + of the slurry supplied to the slurry flow meter 28
On the other hand, the flow rate St of the slurry discharged from the mill 3 is measured with the slurry flowmeter 28a, and the slurry hold amplifier amount in the mill 3 is calculated from the difference between the flow rate SI and the flow rate S2. The rotation speed of the lower ring 21 is controlled so that the slurry hold up amount does not exceed a predetermined value.

Next, the effects of the present invention will be illustrated with specific operational examples.

Operation Example I A slurry was produced using A coal (HGI50) under the following conditions using a mill having a structure as shown in FIG. 2 and having a rotary table with a diameter of 165 mm.

(Conditions) Amount of coal fed to the mill: 20 kg/h (based on pure coal) Amount of surfactant: 0.5% (relative to coal) Coal concentration in the mill is near 2% Upper ring rotation speed: 120 rpm Lower ring rotation speed :6Qrpm Operation Example 2 A slurry was produced using coal (HGI36) in the same manner as Operation Example 1. However, the amount of coal fed to the mill is 10
kg/h, and the coal concentration in the mill was 68%.

Operation Example 3.4 (for comparison) Using the conventional coal-water slurry manufacturing apparatus shown in FIGS. 3 and 4, slurries were manufactured for A coal and coal under the same conditions as Operation Examples 1 and 2, respectively. However, the rotation speed of the lower ring at that time was 18 (l rpm).

Performance Results for Operational Examples 1 to 4 The distribution ratios of the distributor 13 in Operational Examples 1 and 2 were 0.80 and 0.76, respectively. On the other hand, operation example 3.
The distribution ratios of 4 were 0.95 and 0.92, respectively. Comparing this in terms of the amount of slurry supplied to the distributor 13, the amount of slurry supplied to the distributor 13 is approximately 140 kg/h in Operation Example 1, while it is approximately 560 kg/h in Operation Example 3, which is approximately four times that of Operation Example 1. Even when comparing Operation Example 2 and Operation Example 4, the amount in Operation Example 4 is three times higher. That is, with the device of the present invention, the size of the distributor 13 and circulation pump 12 can be reduced to 1/4 to 1/3, and the pump power has also been reduced to 174 to 1/3.

〔Effect of the invention〕

As described above, according to the present invention, the residence time of coal particles can be controlled in the ring roller mill, and the power to crush the coal particles is improved, so devices such as distributors and slurry circulation pumps can be downsized, and the pump power is also significantly reduced. Can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a ring roller mill provided in a coal-water slurry manufacturing apparatus according to the present invention, FIG. 2 is a system diagram of a coal-water slurry manufacturing apparatus equipped with the ring roller mill of FIG. 1, and FIG. System diagram of conventional coal-water slurry production equipment,
FIG. 4 is a sectional view of the ring roller mill in the coal-water slurry production apparatus of FIG. 3. 1... Bunker, 2... Feeder, 3.
·····mill. 4... Coal feed pipe, 5, 6.7... Tank, 13... Distributor, 14... Coarse particle separator, 15... ...Slurry tank, 17...
Grinding table, 18...pressure device. 19... Upper ring, 20... Drive device, 21... Lower ring, 22... Ball, 26... Drive device. Representative Patent Attorney Masaru Nishimoto - Figure 1 M2

Claims (2)

[Claims] (1) A ball is placed between a rotatably installed lower ring and an upper ring installed above the lower ring, and the coal is wet-compressed and ground between the ring and the ball. A coal-water slurry manufacturing apparatus equipped with a ring roller mill, characterized in that the upper ring is rotatably provided in a direction opposite to the rotational direction of the lower ring. (2) The lower ring is based on the slurry hold-up amount in the ring roller mill, which is calculated from the difference between the flow rate of the coal-water slurry introduced into the ring roller mill and the amount of coal-water slurry discharged from the ring roller mill. The coal-water slurry production apparatus according to claim 1, further comprising means for controlling the rotation speed of the coal-water slurry.