Blast furnace top gas analysis system with voltage stabilization protection

Abstract

The utility model discloses a blast furnace top gas analysis system with voltage stabilization and protection, belonging to the technical field of chemical waste gas detection and analysis. The system includes a sampling device, a pretreatment module, and a gas analyzer. After the sampling device collects the blast furnace gas, the sampled gas is transported to the gas analyzer through the pretreatment module. The pretreatment module includes a voltage stabilization unit. The structure of the voltage stabilization unit includes a pressure gauge for collecting the pressure of the sampled gas before entering the filter. The output end of the filter is connected with a pneumatic switching valve. The conveying pipeline of the sampled gas of the pneumatic switching valve is at least divided into two paths. One path is directly connected to a pressure stabilizing valve, and the other path enters the pressure stabilizing valve after passing through an air extraction pump and a check valve in sequence. A needle valve is connected in parallel with the air extraction pump, and the needle valve and the air extraction pump form a sampled gas loop. The pressure gauge is connected with a PLC controller, and the PLC controller controls the pneumatic switching valve by controlling an electromagnetic valve. The utility model has the characteristics of voltage stabilization and safety.

Description

Technical Field

[0001] This utility model belongs to the field of chemical waste gas detection technology, specifically involving a blast furnace top gas analysis system with pressure stabilization protection. Background Technology

[0002] Blast furnace top gas mainly refers to the high-temperature gas mixture generated during blast furnace operation, characterized by high temperature and high flow rate. With the increasing scale of modern blast furnaces and the growing sophistication of automation control technology, the composition of blast furnace top gas, a direct product of the furnace reaction, reflects the furnace's internal conditions. Online monitoring systems for blast furnace top gas play a crucial guiding role in ensuring safe and high-yield operation of the blast furnace and preventing opaque ironmaking processes.

[0003] Due to the high impurity content and complex composition of blast furnace top gas, the pretreatment technology of the sample gas is crucial for the normal operation of the online analysis system. Blast furnace top raw gas contains solid particles such as iron powder, ore, coke, and lime, as well as certain amounts of moisture and sulfur. When these dust particles mix with condensed moisture, they easily form a dense, concrete-like substance that is extremely difficult to process. Utility Model Content

[0004] The present invention aims to provide a blast furnace top gas analysis system with pressure stabilization protection, thereby improving the system's stability.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] A blast furnace top gas analysis system with pressure stabilization protection includes a sampling device, a pretreatment module, and a gas analyzer. The sampling device collects blast furnace gas, which is then processed by the pretreatment module before being delivered to the gas analyzer. The pretreatment module includes a pressure stabilization unit, the structure of which includes:

[0007] Pressure gauge P01 is used to collect the pressure of the sample gas before it enters filter TF01. The output end of filter TF01 is connected to pneumatic switching valve PV02. The sample gas delivery pipeline of pneumatic switching valve is divided into at least two paths. One path is directly connected to pressure regulating valve PR01, and the other path passes through pump DP01 and check valve CV01 in sequence before entering pressure regulating valve PR01. Pump DP01 is connected in parallel with needle valve NV02. The needle valve NV02 and pump DP01 form a sample gas circuit.

[0008] The pressure gauge P01 is connected to the PLC controller, which controls the pneumatic switching valve PV02 by controlling the solenoid valve SXV01.

[0009] In this system, the sampling device is configured for two-stage sampling, including a primary sampling probe and a secondary sampling probe, and a check valve is installed inside the sampling probe.

[0010] The sampling probe of the sampling device includes a filter and a backflush pipeline. The backflush pipeline is equipped with a PLC controller and a control valve. The backflush pipeline includes a connection to a nitrogen source or an instrument air main.

[0011] The sample gas collected by the sampling device enters the pretreatment module through a heated pipeline. The pretreatment includes a tubular cooler and a gas-liquid separator. After passing through the tubular cooler and gas-liquid separator, the sample gas reaches the filter TF01. The output end of the pressure regulating valve PR01 includes a bypass filter BF01. Before entering the gas analyzer, the sample gas includes a membrane filter MS01 and a needle valve flow meter.

[0012] Furthermore, the system includes a bypass pipeline connected to the bypass filter BF01, and a needle valve flow meter and a check valve are installed on the bypass pipeline.

[0013] The pressure regulating valve PR01 includes a pressure gauge, which is connected to an actuation unit for controlling the pneumatic switching valve PV02; the needle valve NV02 is replaced by a solenoid valve, and the actuation unit is a PLC controller.

[0014] Furthermore, the gas analyzer is a chromatograph.

[0015] Furthermore, the system also includes a standard gas pipeline that connects a standard gas source and a switching valve BV01, which is located on the pipeline from the bypass filter BF01 to the gas analyzer.

[0016] Beneficial effects: Compared with the prior art, the system provided by this utility model has voltage stabilization protection, which can improve the analysis effect and the system security. Attached Figure Description

[0017] Figure 1 This is a system structure diagram of the system described in this utility model.

[0018] In the diagram: SXV represents a solenoid valve, BV represents a ball valve, NV represents a needle valve, BXV represents a switching valve, BF represents a bypass filter, FI represents a needle valve flow meter, CV represents a check valve, FR represents an air pressure reducing valve, CR represents a cylinder pressure reducing valve, TF represents a filter, MS represents a mode filter, LVD represents a tube cooler, GLS represents a gas-liquid separator, and GS represents an oil mist filter. Detailed Implementation

[0019] To provide a detailed explanation of the technical solution provided by this utility model, a further description is given below in conjunction with the accompanying drawings.

[0020] Combination Figure 1 The system structure shown in this invention, a blast furnace top gas analysis system with pressure stabilization protection, mainly includes a sampling probe, a first-stage sampling device, a second-stage sampling device, an analyzer, a control box, a dehumidification device, and an instrument panel rack (indoor type). After pretreatment, the blast furnace gas enters the analyzer for analysis, and the results are displayed. Simultaneously, a 4-20mA standard signal is transmitted to the blast furnace main control room PLC for display on the operation screen.

[0021] The sampling device includes a sampling probe (with dual probes and automatic switching) and a sampling transmission line. The sampling probe is installed via a flange or adapter. The gas sampling probe features a check valve, is an integrated electrically heated sampling probe with backflush capability, and should be equipped with a direct-insertion filter and an outdoor protective enclosure with effective insulation, suitable for high-dust and high-humidity environments. Various probe tubes and extensions, filters, calibration gas interfaces, pulse backflush systems, and backflush control units are available as options.

[0022] Control principle: A pressure gauge P01 is added to the back end of the pretreatment to measure the gas pressure in real time during the pretreatment. The pressure signal collected by the pressure gauge P01 is sent to the PLC controller (which is used for backflush control) through hard wiring for processing, controlling the solenoid valve in the backflush box, and then controlling the pneumatic switching valve for switching the sampling probe.

[0023] The backflushing gas source can be nitrogen or instrument air. When the sampling probe is blocked or when the sample gas pressure is found to be reduced, the sampling probe filter is purged using timed or active control, including timed backflushing of the probe to keep the sampling probe unobstructed. Multiple purging methods (pulse blowing, internal blowing, external blowing, combined blowing, and circulating blowing) should be used to ensure the purging effect and guarantee the continuous operation of the system. If the probe is blocked, the sampling probes can be switched between each other through the PLC controller.

[0024] The system is equipped with a multi-stage dust filtration system (including a TF filter, a MS membrane filter, and a GS oil mist filter), with a filtration accuracy of no more than 0.2 microns. The filters are made of highly reliable materials such as sintered stainless steel. The final stage uses filter paper filtration. A vortex dehumidification method is employed to eliminate the influence of moisture in the sample gas on the analytical system. The system includes a MS membrane filter.

[0025] This invention includes a pressure stabilizing unit in the system, comprising a pressure gauge P01 for monitoring the sample gas pressure within the pipeline, and a pneumatic switching valve PV02 for controlling gas path switching. Through the control of the pneumatic switching valve PV02, the sample gas can be directly connected to the pressure stabilizing valve PR01, or the sample gas can enter the pressure stabilizing valve PR01 after passing through a diaphragm pump DP01 and a one-way valve CV01. The data collected by the pressure gauge P01 is sent to the PLC controller. The PLC controller analyzes and controls the solenoid valve SXV01 to provide driving gas to the pneumatic switching valve PV02, thereby preventing explosions caused by contact between flammable and explosive gases and electrical circuits. The control includes:

[0026] Sampling point pressure fluctuation range: 20-280 kPa; when the sampling point pressure is low (20 kPa G), the pressure transmitter (pressure gauge P01) measures the pressure in the pretreatment process, and the pressure is transmitted to the diaphragm pump DP01 via the PLC controller; when the pressure is high, the pressure transmitter (pressure gauge P01) measures the pressure in the pretreatment process, and the diaphragm pump DP01 is shut off via the PLC controller, while simultaneously controlling the solenoid valve SXV01, which in turn controls the pneumatic switching valve PV02 to switch to another path; because the sample pressure is very high (280 kPa G), a check valve is added after the diaphragm pump DP01 to protect it; because the sampling point fluctuation is large, but the instrument requires a stable injection pressure, a pressure regulating valve PR01 is added between the diaphragm pump DP01 and the other path to stabilize the pressure entering the chromatograph and maintain a constant flow rate. The system is highly automated and more sophisticated.

[0027] Other units of the system can be configured in accordance with conventional technologies and technical requirements in the field, including emission requirements for chemical gases and tail gas treatment requirements, as well as analytical requirements for analytical instruments, including calibration and verification. Therefore, the system provided by this invention includes:

[0028] Bypass unit: To accelerate the response speed of the response analysis system, a bypass discharge system should be provided.

[0029] Calibration Unit: The system should include a calibration system to facilitate the calibration of the chromatograph's operating point.

[0030] Control unit: The system described in this utility model is the first to achieve sampling under fluctuating pressure and realize closed-loop control of pressure fluctuation and sampling method through PLC controller.

Claims

1. A blast furnace top gas analysis system with pressure stabilization protection, comprising a sampling device, a pretreatment module, and a gas analyzer, wherein the sampling device collects blast furnace gas, which is then processed by the pretreatment module before being delivered to the gas analyzer, characterized in that, The preprocessing module includes a voltage regulator unit, and the voltage regulator unit structure includes: Pressure gauge P01 is used to measure the pressure of the sample gas before it enters filter TF01. The output end of filter TF01 is connected to pneumatic switching valve PV02. The sample gas delivery pipeline of pneumatic switching valve is divided into at least two paths. One path is directly connected to pressure regulating valve PR01, and the other path passes through pump DP01 and check valve CV01 in sequence before entering pressure regulating valve PR01. Pump DP01 is connected in parallel with needle valve NV02. The needle valve NV02 and pump DP01 form a sample gas circuit. The pressure gauge P01 is connected to the PLC controller, which controls the pneumatic switching valve PV02 by controlling the solenoid valve SXV01.

2. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1, characterized in that, The sampling device is configured for two-stage sampling, including a primary sampling probe and a secondary sampling probe, and a check valve is installed inside the sampling probe.

3. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1 or 2, characterized in that, The sampling probe of the sampling device includes a filter and a backflush pipeline. The backflush pipeline is equipped with a PLC controller and a control valve. The backflush pipeline includes a connection to a nitrogen source or an instrument air main.

4. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1, characterized in that, The sample gas collected by the sampling device enters the pretreatment module through a heated pipeline. The pretreatment includes a tubular cooler and a gas-liquid separator. After passing through the tubular cooler and gas-liquid separator, the sample gas reaches the filter TF01. The output end of the pressure regulating valve PR01 includes a bypass filter BF01. Before entering the gas analyzer, the sample gas includes a membrane filter MS01 and a needle valve flow meter.

5. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1 or 4, characterized in that, The system includes a bypass pipeline connected to a bypass filter BF01, and a needle valve flow meter and a check valve are installed on the bypass pipeline.

6. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1, characterized in that, The pressure regulating valve PR01 includes a pressure gauge, which is connected to an actuation unit for controlling the pneumatic switching valve PV02; the needle valve NV02 is replaced by a solenoid valve, and the actuation unit is a PLC controller.

7. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1 or 4, characterized in that, The gas analyzer mentioned is a chromatograph.

8. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1, characterized in that, The system also includes a standard gas pipeline, which connects the standard gas source and the switching valve BV01. The switching valve BV01 is located on the pipeline from the bypass filter BF01 to the gas analyzer.

9. The blast furnace top gas analysis system with pressure stabilization protection according to claim 1, characterized in that, The aforementioned air pump DP01 is a diaphragm air pump.

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