1、 Overview of the Plan

With the development of large-scale modern blast furnaces, the level of automation control technology is increasing. As a direct product of furnace reactions, the composition and content of the top gas can reflect the conditions inside the furnace. The online monitoring system for blast furnace top gas plays a key guiding role in ensuring safe and high-yield operation of the blast furnace, avoiding black box ironmaking.

SK-7500-BFG typeBlast furnace top gasonline monitoringThe system usually consists of three parts: sampling probe, sample preprocessing, analyzer, etc., and may be equipped with a data acquisition and processing system if necessary. The sampling probe includes a sampling probe with a pre filter and a probe blowback system. The sample gas is sent to the analysis cabinet for sample processing and analysis through an electric tracing transmission pipeline. The analysis cabinet generally includes sample processing components, analyzers, etc.

Due to the continuous process of blast furnace ironmaking, this system mostly adopts dual flow analysis and control technology to continuously monitor the concentration of gases such as CO, CO2, H2 in the flue gas at the top of the blast furnace. In automatic mode, when the flowroad1. Flow during analysisroadPerform blowback replacement and drainage for channel 2, and when analyzing channel 2, perform blowback replacement and drainage for channel 1. Repeat this process to ensure the continuity of the analysis data.

SK-7500-BFG typeBlast furnace top gasonline monitoringThe main components of the system are CO, CO2, H2, O2, and CH4. Analyzing their concentration values plays an important role in determining and adjusting the energy conversion, cooling system, furnace top material distribution, and overall furnace conditions of the blast furnace. The blast furnace gas analysis system consists of a sampling unit, a sample preprocessing unit, an instrument analysis unit, an automation control unit, and a calibration unit, all of which are combined and connected to the analysis system cabinet. The system adopts analytical instruments and fittings, with reliable technology, long maintenance cycle, low operating cost, and simple operation.

The main functions of the system include:

1real-time monitoringChimney ductinflue gasContent.

2Real time monitoring of the on-site situation in the venue through the upper computer system monitoring center.

3Real time recording of the above monitoring data in the monitoring center, and centralized management of the data.

（Schematic diagram of monitoring system）

2、 Execution standards

GB3836.1-2010 Electrical Equipment for Explosive Gas Atmosphere Part 1: General Requirements

GB3836.2-2010 "Electrical equipment for explosive gas atmospheres - Part 2: Explosion proof type" d ""

GB 3836.15-2000 "Electrical equipment for explosive gas atmospheres - Part 15: Electrical installations in hazardous areas (excluding coal mines)"

GBT50493-2019 "Design Standard for Combustible Gas and Toxic Gas Detection and Alarm in Petrochemical Industry"

GB12358-2006 General Technical Requirements for Workplace Gas Detection and Alarm Devices

GBZ 2.1-2007 Occupational Exposure Limits for Hazardous Factors in the Workplace

GB 4208-2008 "Degrees of Protection Provided by Enclosures (IP Code)"

GB 16297-1996 Comprehensive Emission Standards for Air Pollutants

GB/T 16157-1996 "Determination of particulate matter and sampling methods for gaseous pollutants in exhaust from stationary sources"

HJ/T 76-2017 "Technical Requirements and Testing Methods for Continuous Monitoring System of Flue Gas Emissions from Fixed Pollution Sources"

HG/T 20507-2014 "Design Specification for Selection of Automation Instruments"

IIIMonitoring location

4Product Parameters

On line monitoring system for out of stock flue gas

5Overall dimensions

6、 Installation precautions

8.1 Installation method:

8.11 Cabinet fixation

The cabinet should be placed vertically or wall mounted, and the ground should be kept flat. The cabinet should not be tilted.

8.1. 2 Power supply

The cabinet is powered by 220V AC and must ensure good grounding of the ground wire.

8.1. 3 Determine installation location

8.1.3Selection of installation location for the main chassis

Firstly, the temperature tolerance range of the internal sensor components is -20 ℃ to+50 ℃, and the optimal working temperature is around+20 ℃. Therefore, it is necessary to choose a location where the ambient temperature is not lower than -20 ℃ or higher than+50 ℃ for installation.

8.13.2 Distance between sampling point and main box pipeline

The vacuum pump used inside the main chassis is a small vacuum diaphragm pump, with a vacuum degree of around 50KPa to 70KPa. The principle of pipeline length is that the shorter the temperature, the better. The longer the pipeline, the longer the data delay. Generally, there is no problem within 20 meters. It still needs to be determined based on the actual situation on site.

8.2 air circuit connection

8.2Pipeline interface

One sampling inlet enters the system; Gas exhaust outlet after continuous testing; Two way filtration and water removal gas outlet. The interface defaults to a diameter of 6 and can use PU hoses with an outer diameter of 6mm and an inner diameter of 4mm.

8.2.2 Installation of sampling tube(Optional)

Insert the sampling tube into the test areagasThe pipeline is fixed with matching flanges. If the pipeline to be testedgasIf the temperature is higher than the heat-resistant temperature of the sampling tube, the pipeline in the early stage of sampling should adopt heat-resistant pipeline and be pre cooled before connecting to the sampling interface of the detection system with PU hose.

8.2Connection method of gas path discharge interface

Exhaust port: connected with a PU hose with a diameter of 6, mainly discharging the gas detected by the flow detector,

Drainage outlet: Connected with a PU hose with a diameter of 6, most of the sampled gas and water vapor are discharged from here. If the temperature and humidity of the gas pipeline to be tested are high and contain a lot of water vapor, water will flow out of the drainage outlet. Therefore, the drainage pipe should be installed downwards to ensure smooth discharge of water flow.

8.3 Precautions during debugging:

8.3Flow meter control

During system operation, the gas flow rate through the detection instrument is controlled at around 300-500ml/min by adjusting the flow meter and the throttle valve on the lower drainage pipe of the condenser.

8.3. 2 Condenser

The target condensation temperature of the condenser can be set to the default temperature.

8.3. 3 Filters

Regular manual maintenance and cleaning of the dust filter or timely opening of the throttle valve to discharge accumulated water vapor is required to prevent blockage of the air path.

8.3. 4 Temperature controller (optional)

Generally set to 30 ℃ (open lid setting, control the heat tracing temperature of the heat tracing tube, and place the temperature sensing tube externally).

8.3. 5 Heater (optional)

Generally set at 20-30 ℃ (open lid setting, be careful to prevent burns).

8.3Gas concentration detector

The use of the detector is detailed in the user manual of the detector.