The structure and working principle of the fixed coal powder sampler produced by Lianyungang Lingdong Electromechanical Equipment Co., Ltd. are mainly used for regular coal powder sampling on the secondary air coal powder pipe in the positive pressure direct blowing coal powder system. Due to the wear and tear of the grinding components of the coal mill, as well as changes in coal type and block size, the fineness of coal powder will undergo significant changes and directly affect the combustion rate of the boiler. Therefore, it is necessary to regularly sample and measure the fineness of coal powder. When the fineness of coal powder exceeds the design value, it is necessary to adjust the opening of the separator folding door in a timely manner or replace the grinding components.

The fixed coal powder sampler adopts compressed air blowing and suction sampling with an air extractor, which avoids the problem of clogging of the sampling port and is easy to sample. The sampling speed is controlled by controlling the compressed air pressure and flow rate. This can obtain a more accurate value of coal powder fineness.

The fixed coal powder sampler is different from the same type of production in that a pressure regulating valve is installed after the compressed air valve.; Due to the pressure of compressed air provided by power plants being around 6-8Kg, it is difficult to achieve the working pressure required by the coal powder sampling device solely by adjusting the compressed air valve. Sampling distortion often occurs due to high pressure, which does not represent.

2、 Structure of fixed coal powder sampler

The fixed coal powder sampler mainly consists of the following parts:

1. Sampling tube - insert into the coal powder pipeline - with the sampling port facing towards the coal powder airflow, and the coal powder enters the sampling device through this port. The form is sampling.

2. Separators - separate coal powder and gas, and the coal powder is thrown into the wall of the collector by the rotating airflow due to force, and then falls into the collector by force. The separated gas rotates downwards along the wall of the device from top to bottom, then rises along the intermediate path to the bottom, and undergoes secondary separation through the blades at the bottom of the exhaust pipe. It is discharged from the outlet of the part, resulting in the separation of coal powder and gas.

3. Sampling bottle - the fixed coal powder sample separated from the separator is collected and stored for calibration purposes.

4. Sampling valve - When sampling coal powder, open this valve and use the negative pressure formed by the exhaust of compressed air from the outlet to suck the air from the separator, so that the coal powder in the coal powder pipeline enters the sampling device from the sampling port for sampling.

5. Blowing valve - When it is necessary to clean the residual coal powder in the sampling pipe, close the sampling valve and pressure regulating valve, and open the blowing valve to use compressed air to blow the sampling pipe.

6. Pressure regulating valve - adjusting the opening of this valve can control the pressure and flow rate of compressed air and change the sampling speed of the sampling device. The pressure cannot be adjusted too high to prevent distortion in coal powder sampling.

7. Pressure gauge - provides intuitive basis for the operation of pressure regulating valves.

3、 Working principle of fixed coal powder sampler

The fixed coal powder sampler is developed using the principles of negative pressure suction and cyclone separation to extract coal powder from the coal powder pipeline and perform solid and gas separation. Lianyungang Lingdong Electromechanical Equipment Co., Ltd. is now explaining the process of coal powder sampling.

During the coal powder sampling process, all valves are in an open state. When compressed air is sprayed out from the outlet pipe, its jet action causes negative pressure at the pipeline connected to the sampling valve, and the gas inside the pipeline is carried out. The separator and its bottom powder collection bottle are enclosed and can be connected to the outside - only the sampling head and sampling tube. So the emergence of negative pressure causes the coal powder in the coal powder pipe to enter the sampling device along the sampling head. The coal powder is separated again in the separator and enters the powder collection bottle. The gas and a small amount of fine powder are separated again from the upper outlet of the separator through the blades in the outlet pipe, and are carried out by compressed air and sent into the coal powder pipeline, which does not cause pollution to the workplace.

The function of adding a blowing valve is to close the blowing valve after coal powder sampling, and open the sampling valve to blow away the residual coal powder in the sampling pipe to prevent the sampling pipe from being blocked by coal powder. And ensure accurate sampling.

4、 Operating Procedure for Fixed Coal Powder Sampler

Purging:

Sampling - The sampling tube should be blown clean to prevent coal powder from blocking the sampling tube.

1. Open sampling control valve 11; Close the purge valve 9; Blow the sampling tube for 1-3 minutes, close all valves to clean the coal powder in the sampling bottle, place the sampling bottle back in its original position, and pay attention to the sealing between the sampling bottle mouth and the separator interface.

Sampling:

Sampling - all valves are closed, - open compressed air valve 6; Adjust the pressure of the pressure regulating valve according to the pressure gauge 7 on the compressed air pressure regulating valve, and adjust the compressed air pressure to the required pressure range of 0.05-0.1MPa.

When adjusting the compressed air pressure, open all ball valves to start sampling. The sampling time is determined based on the pressure of the compressed air, usually 1-2 minutes. After sampling is completed, close all valves, remove the sampling bottle, and take out the sample; Return the sampling bottle to its original position and seal the interface.

Model: MF-XXX

Model description: MF: Coal powder sampler. XXX: Coal powder pipeline diameter.

5、 Composition structure of fixed coal powder sampler-

1. Sampling tube 2, sampling bottle 3, separator 4, movable joint 5, compressed air connection pipe 6, compressed air valve 7, pressure regulating valve 8, injection air extractor 9, blowing valve 10, injection pipe 11, sampling valve

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