JPH0226664B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an apparatus for producing highly concentrated coal/water slurry.

[Conventional technology]

High concentration coal/water slurry (hereinafter abbreviated as CWM)
There are three main types of manufacturing methods: dry method, high concentration wet method, and low concentration wet dehydration method. The dry method is a method in which water and additives are added to dry pulverized coal, mixed and stirred to form CWM. In the high-concentration wet method, coal, water, and additives are charged into the pulverizer in advance in a highly concentrated state, and the
This is a method of CWM. The third low-concentration wet dehydration adjustment method involves pulverizing coal in a low-concentration state with water in a pulverizer to create a low-concentration slurry, which is then dehydrated in a dehydrator to form a cake, and then added to this cake. Add the agent and a small amount of water, mix and stir.
This is a method of CWM.

Incidentally, as a CWM manufacturing apparatus using the above-mentioned low concentration wet dehydration adjustment method, one having the structure shown in FIG. 2 has been known. In other words, 1 in the figure
is a pulverizer for preparing low concentration slurry by pulverizing coal and water. This crusher has two coal supply pipes.
and water supply pipe 3 are connected to each other. The crusher 1 is connected to a dehydrator 5 via a pipe 4 through which the low concentration slurry flows. This dehydrator 5 is attached with a conveyor 8 for supplying a dehydrated cake 6 discharged from the dehydrator 5 to a slurry adjustment tank 7. Note that water generated in the dehydrator 5 is supplied to the water supply pipe 3 through a circulation pipe 9. A stirrer 10 is provided in the slurry adjustment tank 7. In addition, a water supply pipe 1 is provided in the slurry adjustment tank 7.
1 are connected to each other, and an on-off valve 12 is interposed in the water supply pipe 11. An additive supply pipe 13 is connected to the slurry adjustment tank 7.
Further, at the bottom of the slurry adjustment tank 7, a blended
A pipe 14 for discharging CWM is connected.

[Problem that the invention seeks to solve]

In the manufacturing apparatus shown in FIG. 2 described above, in order to maintain a constant concentration of CWM discharged from the slurry adjustment tank 7, it is necessary to know the concentration (moisture) and flow rate (conveyance amount) of the dehydrated cake 6 from the dehydrator 5. , is calculated taking into account the properties of the cake and the amount of additive injected into the slurry adjustment tank 7 from the additive supply pipe 13, and controls the on-off valve 12 of the water supply pipe 11 to achieve the target concentration of CWM. It is necessary to supply necessary water to the slurry adjustment tank 7 from the water supply pipe 11. The amount of additive to be injected from the additive supply pipe 13 is determined based on the amount of CWM discharged from the slurry adjustment tank 7 or the amount of coal supplied from the coal supply pipe 2 to the crusher 1, etc.

However, conventionally, the only method for detecting the concentration (moisture) of the dehydrated cake discharged from the dehydrator 5 is analysis by sampling (loss on drying method), which requires about 1 hour for analysis.
Therefore, when controlling the concentration of CWM, there is a large time delay, making it difficult to continuously obtain a constant concentration of CWM, and it is necessary to perform sampling and analysis frequently, which requires a great deal of time and effort. There was a problem.

The present invention has been made to solve the above problems, and aims to provide a CWM manufacturing apparatus that can automatically and continuously control the concentration of CWM.

[Means and actions for solving problems]

The present invention comprises a crusher supplied with coal and water;
A dehydrator to which the low-concentration slurry in the pulverizer is supplied through piping, a conveyor to supply the dehydrated cake discharged from the dehydrator to a slurry adjustment tank, and an on-off valve connected to the slurry adjustment tank. A measuring device for measuring the weight flow rate of the conveyor dewatered cake in a highly concentrated coal/water slurry production apparatus comprising a water supply pipe interposed with a water supply pipe and an additive supply pipe connected to the slurry adjustment tank. At the same time, a flow meter and a density meter are installed in the pipe through which the low concentration slurry flows, and the opening degree of the on-off valve of the water supply pipe is adjusted based on the signals from these meters, the flow meter, and the density meter. It is characterized by the addition of a controller. According to the present invention, the concentration (moisture content) and flow rate (conveyed amount) of the dehydrated cake from the dehydrator can be continuously detected using a measuring instrument, a flow meter, and a density meter, and a controller to which these detection signals are input. By adjusting the opening degree of the on-off valve of the water supply pipe, it becomes possible to automatically and continuously control the concentration of CWM.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to FIG. Note that the same members as those in the manufacturing apparatus shown in FIG.

15 in the figure is a pipe 4 through which the low concentration slurry flows.
This is a density meter installed in the slurry to measure the density of the slurry. This density meter 15 may be of a single tube type, a vibration type, a gamma ray type, or the like. The density meter 15
A first flow meter 16 for measuring the flow rate of the low concentration slurry is installed in the pipe 4 on the latter stage side. Reference numeral 17 in the figure denotes a measuring device, for example, a load cell type, which is attached to the conveyor 8 and used to measure the weight flow rate of the dehydrated cake 6 on the conveyor 8.
18 in the figure is a second flow meter 19 that is installed in the water replenishment pipe 11 between the slurry adjustment tank 7 and the on-off valve (electromagnetic valve) 12 to measure the amount of water to be replenished;
is a third flow meter installed in the additive supply pipe 13 for measuring the injection amount of the additive. Further, 20 in the figure is a controller for controlling the CWM concentration. This controller 20 includes the density meter 15.
The density signal S ₁ of the low concentration slurry measured in the first
Flow rate signal of low concentration slurry measured by flow meter 16 of
S ₂ , a weight flow rate signal S ₃ of the dehydrated cake 6 measured by the measuring device 17 , a flow rate signal S ₄ of the make-up water measured by the second flow rate 18 , and a weight flow rate signal S 4 of the additive measured by the third flow meter 19 . A flow rate signal _S5 is respectively input. Further, a preset coal true specific gravity signal S ₆ , a preset CWM target concentration signal S ₇ , and a preset additive density signal S ₈ are input to the controller 20, respectively. be done. Furthermore, the controller 20 controls the on-off valve 12 based on each of the signals S ₁ to S ₈ .
A control signal S ₉ is output to the on-off valve 12 to adjust the opening degree of the on-off valve 12 .

When a production apparatus having such a configuration is operated, the coal concentration in the low concentration slurry supplied from the crusher 1 to the dehydrator 5 and the weight flow rate of dry coal are calculated by the following equation.

Coal concentration = (S ₁ -1) / (S ₆ -1)・S ₆ /S ₁ Dry coal weight flow rate = (S ₁ -1) / (S ₆ -1)・S ₆ /S ₁・S ₁
・S ₂ = (S ₁ -1) / (S ₆ -1) ・S ₆・S ₂ On the other hand, the weight flow rate of the dehydrated cake 6 discharged from the dehydrator 5 is measured by the measuring device 8 as a signal S ₃ . The weight flow rate of dry coal before and after the dehydrator 5 is:
Since it is assumed to be unchanged, the dehydrated cake concentration is calculated by the following formula.

Dehydrated cake concentration = (S ₁ -1) / (S ₆ -1)・S ₆・S ₂・
1/S ₃ Based on this formula, the flow rate of water to be mixed in the slurry adjustment tank 7 is calculated as shown in the following formula.

Flow rate of water to be mixed = (dry coal weight flow rate) / S ₇ −S ₃ −S ₈・S ₅ = [(S ₁ −1) / (S ₆ −1)・S ₆・S ₂ ]/S ₇ −S ₃ −S ₈
・_S5 The amount of water to be mixed is calculated by the controller 20, and the amount of water and the flow rate signal _S4 of the make-up water from the second flow meter 18 installed in the water make-up pipe 11 are calculated. By outputting a control signal S ₉ from the controller 20 to the on-off valve 12 based on the deviation, the slurry adjustment tank 7 can be replenished with the water necessary to achieve the target concentration of CWM from the water replenishment pipe 11 . Therefore, the concentration of CWM discharged from the slurry adjustment tank 7 can be automatically and continuously controlled by the controller 20.

In addition, in the manufacturing equipment shown in Fig. 1 mentioned above, a density meter is also installed on the CWM discharge side of the slurry adjustment tank 7.
The configuration may be such that the density of CWM is measured and the control by the controller is corrected again based on the density.

〔Effect of the invention〕

As detailed above, according to the present invention, the concentration of CWM can be automatically and continuously controlled without performing any dehydration cake, other sampling, analysis, etc., and the concentration of low concentration slurry, dry coal weight flow rate, etc. can be controlled automatically and continuously.
It is possible to provide a high-concentration coal/water slurry manufacturing apparatus that can display and record state values such as dehydrated cake weight flow rate and dehydrated cake concentration on an indicator and can perform simple operation management.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing a CWM manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a flow sheet showing a conventional CWM manufacturing apparatus. 1...Crusher, 4...Piping through which low concentration slurry flows, 5...Dehydrator, 6...Dehydrated cake, 7...
Slurry adjustment tank, 8... Conveyor, 11... Water supply piping, 12... Open/close valve, 13... Additive supply piping, 15... Density meter, 16, 18, 19... Flow meter, 17... Measuring instrument, 20...controller.

Claims (1)

[Claims] 1. A pulverizer to which coal and water are supplied, a dehydrator to which the low concentration slurry in the pulverizer is supplied through piping, and a conveyor to supply the dehydrated cake discharged from the dehydrator to a slurry adjustment tank. A highly concentrated coal/water slurry production apparatus comprising a water supply pipe connected to the slurry adjustment tank and having an on-off valve interposed therebetween, and an additive supply pipe connected to the slurry adjustment tank, A measuring device for measuring the weight flow rate of the dehydrated cake is installed on the conveyor, and a flow meter and a density meter are installed in the piping through which the low concentration slurry flows, and based on the signals from these measuring devices, the flow meter and the density meter. A highly concentrated coal/water slurry manufacturing apparatus, characterized in that a controller is attached for adjusting the opening degree of the on-off valve of the water supply pipe.