Dust Monitoring Based on Laser Forward Scattering Method, Support Automatic Purging to Clean Gas Path and Avoid Dust Blocking

• Customization: Available
• Warranty: 12 Months
• Brand: Yuan Zheng
• Model NO.: DMT-300
• Customized: Non-Customized
• Portable: Non Portable
• Certification: CE
• Gas: So2, Nox (No, No2), CH4, Nh3, HCl, Hf, Co, CO2, O2
• Type: Laser Gas Analyzer
• Transport Package: Carbon Box
• Specification: 15 Kg
• Trademark: YUAN ZHENG
• Origin: China
• Production Capacity: >1000 Units/Year

Product Description

DMT-300 Dust monitor

DMT-300 dust monitor is a self-developed high-temperature heat tracing extraction dust monitor, based on years of technology research and development for dust detection. Different from conventional in-situ scattering dust monitor, DMT-300 extracts dust from flue (stack) in uniform speed to dust measurement module with full-process high-temperature heat tracing for measurement. It owns features of low detection limit (as low as 0.05mg/m3), no interference by moisture, high measurement accuracy, and etc. It applies to low temperature and high humidity dust conditions of super clean emission and after wet desulphurization.


Application
The  DMT-300 dust particle measuring device is widely applied in enterprises including thermal power, ferrous metallurgy, petrochemical industry, cement production, potting, waste incineration; flue gas emission monitoring in all kinds of power generating boiler, industrial kiln, and industrial boiler; monitoring and control in gas desulphurization and dust removal process.

Feature
•    Adopt the laser forward scattering method to detect dust concentration; low detection limit.
•    Full-process heat tracing, which heats water vapor to the gaseous state to prevent dust from caking and blocking gas path when encountering water. Thus it applies to high humidity occasion.
•    Pitot tube isokinetic sampling method meets the technical condition of dust sampling
•    Support automatic purging to clean gas path and avoid dust blocking
•    Support automatic zeroing technology under high temperature and automatic calibration technology of all optical paths
•    Support on-site manual span calibration
•    Support automatic double-range switching


Working principle

Under the negative pressure effect of the jet pump, dust in the stack enters the measurement module after being heated by tracing the sampling probe. Heat tracing will be in the whole process of extraction, measurement, and emission to eliminate moisture interference and prevent dust from blocking the gas path if encountering condensate water. The dust after being heated enters the measurement module, where the laser forward scattering dust monitor principle is used to measure dust concentration. After the measurement, the exhaust gas goes into the stack again.

DMS-300 manufactured by ZETIAN, one of the best continuous emission monitoring system suppliers, employs a magnetic valve and control unit to realize the automatic purging of the gas path and measurement module. Automatic zeroing shall be performed termly.  After maintenance, close laser device and insert calibration module for manual zeroing and calibration. Micro differential pressure transmitter and pitot tube are used to measure gas velocity in stack and feedback to the flow-control device at the same time. It can realize isokinetic sampling and isokinetic flue dust extraction for measurement of pitot tube by changing the jet gas flow to control extraction velocity.


Composition

 

The extraction dust monitor is composed by jet gas control unit (1, 2),  measurement unit (3, 4, 5, 8, 9), control & display unit (7),  and gas path control unit (6,10, 11, 12).   The flue gas inside stack is extracted to measurement unit in constant speed by gas path control unit. Measurement unit is with full-process high temperature tracing to eliminate influence from moisture to dust measurement. Actual concentration signal is processed and displayed by control &display unit. The gas control unit is able to achieve flue gas isokinetic extraction and reflect real dust concentration through velocity measurement inside stack, extraction velocity measurement of gas path, and velocity valve adjustment.The extraction dust monitor is composed of a jet gas control unit (1, 2),  measurement unit (3, 4, 5, 8, 9), control & display unit (7),  and gas path control unit (6,10, 11, 12).   The flue gas inside stack is extracted to the measurement unit at a constant speed by the gas path control unit. Measurement unit is with full-process high temperature tracing to eliminate influence from moisture to dust measurement. The actual concentration signal is processed and displayed by the control &display unit. The gas control unit is able to achieve flue gas isokinetic extraction and reflect real dust concentration through velocity measurement inside the stack, extraction velocity measurement of the gas path, and velocity valve adjustment.


Specification

Measurement Data
MeasuringPrinciple	Laser forward scattering
MeasuringRange	0~20mg/m3, 0~50mg/m3 (customizable)
Detection Lower Limit	0.05mg/m3
IndicationError	±20%
Indication Error Repeatability	±10%
Response Time	2s (optional)
Laser Device	650nm, 20mW
Measurement Condition
Sampling Head Diameter	6mm, 8mm, 10mm, 12mm (customize according to working condition)
Heat Tracing Temperature	120ºC~180ºC
Medium Temperature	<300ºC
Ambient Temperature	-20ºC~+50ºC
Compressed Air	No water and oil,≥0.4MPa, gas consumption 100L/min
Purging Time	Purge 3min (concentration data keeps), interval period 4h (adjust according to working condition )
Velocity Range	(2~40)m/s
Preheating Time	15min
Input, Output and Interface
Analog Output	4-20mA, maximum load 500Ω
Communication Interface	Rs485, RS232 (optional)
General Information
Weight	103kg
Dimension	1620mm(H)* 850mm(L)* 264mm(D)
Power	1500W
Supply	220VAC