Online oxygen analyzer at the rear end of electric coke capture

1、 Equipment Overview

Online oxygen analyzer at the rear end of electric coke captureIt is a gas monitoring device installed in the outlet pipeline of the electric tar catcher, which uses electrochemical sensors or laser spectroscopy technology to continuously monitor the oxygen content in gas in real time. The equipment has explosion-proof design（Ex d ⅡC T6 Gb）Suitable for environments with flammable and explosive gases such as coke oven gas and generator gas, with a detection range0-5%O₂, accuracy±0.1%FSResponse time≤15Provide critical data support for the safe operation of the electric coke capture system in seconds.

2、 Working principle

Online oxygen analyzer at the rear end of electric coke captureThe detection unit based on electrochemical sensing technology is in contact with the sample gas through a gas diffusion membrane. Oxygen undergoes oxidation reaction at the working electrode to generate a current signal, which is converted into4-20mAStandard signal. The laser analyzer utilizes the absorption characteristics of oxygen molecules towards specific wavelengths of laser, byBeer-LambertThe law calculates concentration. The equipment integrates a sample gas pretreatment system, including dust removal, dehydration, and pressure stabilization devices, to ensure that the cleanliness of the sample gas meets the working requirements of the sensor (dust)≤5μmDew point≤5℃）.

3、 System composition

1. Analysis UnitIncluding sensor module, temperature compensation circuit, microprocessor, supporting automatic calibration function (zero point)/Range calibration cycle can be set)

2. Preprocessing UnitCyclone separator (separation particle size>10μmDust), semiconductor cooler (reducing the temperature of the sample gas to5-10℃）Precision filter (filtration accuracy)0.2μm）Peristaltic pump (waste liquid discharge)

3. control unit：PLCController, configuration7Inch touch screen, realizing data display, parameter setting, alarm output (high)/Low limit alarm relay contacts

4. auxiliary systemIntrinsic safety sampling pump (flow rate)0.5-1L/min）Standard gas interface (standard configuration)1/4'NPTInternal thread), instrument air pretreatment module (pressure)0.4-0.6MPa）

4、 Technical parameters

5、 Installation specifications

1. Sampling point selectionDownstream of the electric coke outlet3-5Double the diameter of the straight pipe section, avoiding turbulent areas such as bends and valves, and the depth of insertion of the sampling probe≥pipe diameter1/3

2. Installation methodWall mounted installation, with the bottom of the instrument box above the ground1.5-1.8mThe sampling pipeline adopts316Stainless steel material (length)≤15m）Control the heat tracing temperature within40-60℃

3. electrical connectionThe power cable adoptsRVV3×1.5mm²(Laying through galvanized steel pipes), signal cables use shielded twisted pair (single end grounded)

4. Calibration interface: Set up calibration gas path ball valve, equipped with standard gas pressure reducing valve (output pressure)0.1MPa）Calibration gas selection99.999%N ₂(Zero point gas) and2.00%O ₂/N₂(Range gas)

6、 Operation and maintenance

1. routine maintenanceCheck flow and pressure parameters daily, clean filter cartridges weekly (pressure difference>0.1MPaVerify temperature compensation accuracy on a monthly basis (when replaced)

2. periodic calibration: Every3Perform zero point calibration every month, every6Perform range calibration every month, and before calibration, blow the pipeline with standard gas5More than minutes

3. Fault handlingAging activation when sensor drift exceeds tolerance（40℃constant temperature heating24Hours), used for pre-treatment of blockages5%Reverse flushing with nitric acid solution

4. Replacement of spare parts: Lifespan of electrochemical sensors2Year (recommended spare parts), drying tube silicone discoloration exceeds2/3When replacing, the frost thickness of the refrigeration fins should be greater than2mmNeed to check the temperature control system

7、 Safety interlock

1. Alarm SettingsLevel 1 alarmO₂＞0.8%(Sound and light alarm), Level 2 alarmO₂＞1.2%(Trigger electric capture coke power-off protection)

2. interlocking logicWhen the oxygen concentration continues30Exceeding the second level alarm value in seconds, the system outputsDOCut off the high-voltage power supply of the electric coke trap and open the nitrogen purge valve at the same time

3. data recording: Possess1Annual data storage capacity（1Minute intervals), supportedUDisk export（CSVFormat), meeting the requirements of the "Safety Regulations for Special Operations in Hazardous Chemical Enterprises"

8、 Application value

1. security guaranteeReal time monitoring of oxygen leakage caused by internal insulation aging, cathode wire damage, and other faults in electric coke traps to prevent gas explosion risks (coke oven gas explosion limit)5.0-31.0%）

2. process optimizationAnalyze the operating efficiency of electric coke capture by analyzing the trend of oxygen content changes, and guide the adjustment of tar mist capture effect (under normal working conditions)O₂The content should be less than0.5%）

3. Environmental compliance standardsTo avoid excessive oxygen entering the subsequent desulfurization and benzene removal systems, reduce the probability of side reactions, and minimize the generation of pollutants such as sulfur and acid mist

4. intelligent management: Factory accessDCSThe system implements remote monitoring and historical data trend analysis to provide data support for preventive maintenance of equipment

9、 Quality standards

Execution standard:

·GB 3836.1-2010Explosive Environment1Part: General Requirements for Equipment

·GB/T 13933-2010Technical specifications for online gas analysis instruments

·AQ 2018-2008Guidelines for the Implementation of Hazard Investigation and Management in Hazardous Chemical Enterprises

·HJ 1013-2018Technical requirements for continuous monitoring system of non methane total hydrocarbons in fixed pollution source exhaust gas

10、 Scope of Supply

This plan establishes a safety warning mechanism for the gas system by monitoring the oxygen content at the outlet of the electric coke collector in real-time, which is in line with the coking industry'intrinsic safety'Management requirements can effectively reduce the risk of explosion accidents and improve production continuity. The overall design of the equipment meets the requirementsGB 50493-2019The "Design Standard for Combustible Gas and Toxic Gas Detection and Alarm in Petrochemical Industry" is standardized and has an explosion-proof certificate issued by the National Explosion proof Electrical Product Quality Supervision and Inspection Center.