Dynamic Density Control for Dense Medium Process

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Admin 2022-11-25 16:23:48 106

Dynamic Density Control for Dense Medium Process

The density control system automatically adjusts the set density in real time to realize unattended operation. It is mainly applied to two types of dense medium separation systems: Dense medium separator system and Dense medium cyclone system.

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1.Intelligent Density Control System for dense Medium Separator in a Coal Preparation Plant

  1. Replace the Gradiomanometer and Liquid level meter.

  2. Increase the magnetic medium meter, upstream, horizontal flow is now a manual knife gate valve, to ensure improved the efficiency of the pneumatic valve replaced in front to this position, 5 valves each.

  3. Connect the water supply valve and divert valve to the density control system.

  4. The final control goal is to stabilize the setting density of 1.85kg/L.

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2.Intelligent density control system for the first stage dense medium cyclone in a coal preparation plant

  1. Add a qualification medium pump and a tank, add a Gradiomanometer on the outlet pipeline of the qualification medium pump;

  2. The valves before and after the pump are connected to the intelligent density control system (wear-resistant valve), and the water supply valve and divert valve are connected to the density control system.

  3. Add magnetic medium meter and level meter;

  4. Calibrate the ash monitor on the belt of 706 and 707, and access the data to the control system;

  5. When producing low ash refined coal, the ash separator data is used as the basis for the system density adjustment parameters, and when thermal coal is produced, the ash analyzer data is used as the feedback data of the washing results.

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3. Intelligent density control system for the second stage dense medium cyclone in a coal preparation plant

  1. Add a qualification medium pump and a tank, add a Gradiomanometer on the outlet pipeline of the qualification medium pump.

  2. The valves before and after the pump are connected to the intelligent density control system (wear-resistant valve), and the water supply valve and divert valve are connected to the density control system.

  3. Add magnetic medium.

  4. The main control target is to stabilize the set density value of 2.00kg/L.

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Critical Equipment

1.Online Ash & moisture analyzer

Status:

1) A coal preparation plant has two radioactive source ash monitors, which are placed in two final coal upper bin belt machines, and the data fluctuates greatly.

2) There is no online ash & water monitor on the raw coal belt, and there is no raw coal ash data to guide production.


Solution:

1) The product does not use radioactive sources, no rays are generated when power is cut off, and it is safe and reliable.

2) Using the principle of combining X-fluorescence technology and X-ray absorption, the measurement method of reflection and transmission solves the influence of the change of element content in coal, the change of coal thickness and density on the measurement.

3) Real-time detection results are given, which solves the lag problem of traditional mining, production and transformation.

4) Low maintenance - modular design, simple installation and low maintenance.

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Two new side-line X-ray ash & moisture monitors have been added for use with samplers. Calibrate the ash monitor of the two final coal bunker belt conveyors, access the data to the tight control system, guide the density control, record the online ash measurement data into the system, establish the coal quality information database, and provide data support for coal quality application analysis.


Installation Location: Raw coal belt conveyor/ Refined coal belt machine


Technical Parameter

Measuring Accuracy of Ash Content

Ash Content ≤15%

≤0.5%, 1σ

Ash Content 15%~30%

≤1.0%, 1σ

Ash Content ≥30%

≤1.5%, 1σ

Measuring Accuracy of Moisture Content

5%~10%

≤0.5%, 1σ

10%~20%

≤1.5%, 1σ

More Than 20%

≤2.0%, 1σ

Reference Accuracy of Calorific Value

(The Specific Accuracy Is Given According to The   Site Conditions)

Clean Coal

≤100kcal/Kg, 1σ

Low Ash Raw Coal

≤150kcal/Kg, 1σ

High Ash Raw Coal

≤200kcal/Kg, 1σ

 

2. Density Meter and Other Equipment

Status:

1) The current age or unreasonable installation of the density meter in the coal preparation plant is inaccurate, and the density control is guided by manual measurement.

2) Non-magnetic content meter, used with density meter to avoid virtual density.

3) The pressure sensor is not accurate.

4) The level meter is not accurate.


Solution:

The instrument selects high-precision, good stability instruments, cooperates with the technical transformation of the coal preparation plant, installs in strict accordance with the instrument installation requirements, and all instrument data is connected to the newly added density control PLC cabinet, and real-time online monitoring of each monitoring amount of density control.

NO.

NAME

SPECIFICATIONS

UNIT

QUANTITY

1

Gradiomanometer

CYYC

Sets

4

2

Magnetic medium meter

DN150

Sets

4

3

Pressure sensor

0.4MPa

Sets

4

4

Pressure level meter

5m/0.06MPa

Sets

13


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Gradiomanometer

Voltage: DC24V

Wiring Mode: Two-wire Type

Density Range: 0-2g/Cm³

Signal Output: 420ma

Measurement Accuracy: 0.001gcm³

Probe Distance: 1m/1.5m


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Pressure Sensor

Measuring Range: 0~0.4MPa

Measurement Accuracy: ± 0.15% FS

Temperature Self Compensation

Protection Grade: IP65

Medium Temperature: - 40 ℃~+110 ° C

Ambient Temperature: - 40 ° C~+60 ° C

 

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Magnetic Medium Meter

Measuring Range: 0~1000g

Measurement Accuracy: Indication ± 1%

Resolution: ± 1 Word

Host Output: 4~20mADC

Power Supply: 220V ± 10% AC, 50Hz

 

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Pressure Level Meter

Measuring Range: 5m/0.06MPa

Measurement Accuracy: ± 0.15% FS

Temperature Self Compensation

Protection Grade: IP65

Medium Temperature: 40 ° C~+110 ° C

Ambient Temperature: 40 ° C~+60 ° C