The Coal Powder Sampler is a constant velocity sampling device specifically designed for thermal power plants, coal-fired power plants, and coal powder boiler systems. It is used to obtain uniform and representative coal powder samples from the primary air-coal powder pipeline, for the detection of coal powder fineness, moisture content, ash content, and other indicators, guiding the optimization of boiler combustion and ensuring the economic and environmentally friendly operation of the unit.
I. Core Working Principle
Comply with the National Standard for Uniform Rate Sampling (GB/T 18511):
The airflow velocity at the nozzle is consistent with the coal powder airflow velocity inside the pipeline, preventing flow rate discrepancies from causing inaccuracies in the sampling of coarse and fine powders; combined with vacuum suction/air blast cleaning, it achieves targeted, full-cross-section sampling with strong sample representativeness.
II. Main Categories
By level of automation
Manual Push-Type Coal Powder Sampler: Manually push/pull the sampling gun, simple structure, low cost, suitable for small and medium-sized units.
Semi-automatic Coal Powder Sampler: Electric telescopic sampling gun, reducing manual operation intensity
Fully Automatic Coal Powder Sampler: PLC controlled, automatically performs extension/retraction → isokinetic sampling → blowing → reset, with remote control capability, suitable for large-scale thermal power units
2. By installation and usage method
Fixed installation: Permanently mounted on a single coal powder pipeline for long-term,定点 sampling
Portable: Compact, mobile, multi-tube wheel-type inspection and sampling
Retractable/Extendable: During non-operation, the sampling tube withdraws from the pipeline airflow, significantly reducing erosion and wear.
III. Core Structure Composition
Sampling Gun/Sampling Probe: Wear-resistant stainless steel material, uniform sampling orifice design
Extendable Thrust Mechanism: Electric / Manual, for probe entry and exit from the pipeline
Vacuum Extraction Components: Water Jet Extractor / Gas Jet Extractor, providing sampling power
Gas and dust separator: Separates coal dust from compressed air, collects samples
Blow-off System: Compressed air blow-off piping, anti-blocking and anti-dust accumulation
Control Box / Gauge: Differential Pressure Monitoring, Constant Speed Adjustment, Stroke Control
IV. Key Performance Features
Constant speed error ≤ ±5%, sampling results are accurate and reliable
Self-cleaning function, no clogging or powder accumulation
Full stainless steel material, wear and temperature resistant, suitable for high-temperature coal powder gas flow
Easy installation, flange/tubing-style quick connection to piping
Fully automatic models can operate unattended and perform timed sampling.
V. Applicable Working Conditions and Scenarios
Applicable Medium: Coal Powder + Primary Air Mixture Flow
Common Parameters: Wind temperature ≤ 350°C, pressure ≤ 0.25 MPa, flow rate 10-30 m/s
Application Scenarios: Direct Blowing Milling System, Intermediate Storage Milling System, Coal Powder Boiler Commissioning and Routine Inspection
Section 6: Key Selection Parameters
Coal powder pipeline nominal diameter DN
Medium Temperature, Operating Pressure, Airflow Velocity
Sampling Method: Manual / Electric / Fully Automatic
Installation Type: Fixed/Portable, Flanged/Welded
Material Requirements: 304/316L Stainless Steel, Wear-Resistant Coating
