I. Overview of Bag Dust Removal Leak Tester
With the advancement of industrial automation and increasing environmental protection efforts, the monitoring of industrial dust has become increasingly stringent. Our developed bag dust collector online monitoring instrument is an effective online monitoring device that checks for bag damage and dust content in each chamber of the dust collector. It can accurately and promptly detect and prevent the emission of harmful dust and reduce the loss of useful powders, aiming to ensure the safe operation of the main equipment and minimize economic losses due to product damage. It also provides instant feedback on the operational status of each dust collector chamber.
This instrument is widely used for leak detection in dust collection systems in metallurgy, power, chemical industry, food processing, building materials, and wood processing. When used for leak detection in the dry ash removal system of large-scale thermal power generating units, it can prevent wear on the vacuum fan due to the rupture of the dust collector bags, as well as prevent excessive dust emissions and air pollution after the positive pressure ash removal and dust-powder separation. Particularly valuable is its use for leak detection in blast furnace gas dust collectors during the ironmaking process in metallurgy, where the gas is highly toxic (with CO content close to 30%) and operates at positive pressure. Over the past decade, from small to large furnaces (up to 2500 M³) and from a single trial installation to multiple installations (with some manufacturers installing several units), this instrument has proven to be sensitive, reliable, with minimal maintenance requirements, and highly practical, meeting production needs. It can replace manual leak detection, provide real-time concentration display, and offers significant economic, social, and environmental benefits, making it highly valuable for widespread application.
The HDLBJ-7 Bag Filter Leak Detector has two series. One series allows for the simultaneous online detection of the operating conditions of up to 8, 10, or 12 bag filter units. This series features computerized patrol inspection, over-limit indicator lights, sound alarms, and 4-20mA analog current indication with switch quantity output. The other series not only monitors the operating conditions of the filter units online but also comes with a main duct concentration meter for real-time online monitoring of dust concentration in the main duct. This series displays the dust concentration values of each bag filter unit and the main duct on a liquid crystal display, and includes dust over-limit and sensor failure alarms; it also outputs 4-20mA current, RS485 interface, and switch quantity output (passive).
The HDLBJ-7 series instruments feature a simple structure, high sensitivity, accurate and timely signals, safe and reliable operation, easy installation, minimal maintenance, and a wide application range (including various types of dust, positive and negative pressure systems, and a broad range of dust particle sizes). They are truly practical online dust monitoring devices for various industrial enterprises.
Section 2: Principle of Bag Filter Leak Detection Instrument
In flowing powdered materials, static charges are generated between particles and particles, particles and tube walls, and particles and filter bags due to friction and collisions, creating a static field. The changes in this static field reflect the variation in dust content. The leak detector measures these changes in the static field to determine if the filter bag dust removal system is operating normally. When the filter bags rupture, the dust content in the gas-solid two-phase flow within the pipeline increases, along with an enhancement in the static field intensity.
This set consists mainly of three parts: ①Sensor (signal collection section), ②Transmitter (signal processing section), and ③Signal Transmission. The block diagram principle is shown in Figure 1, and the function points and keypad layout are depicted in Figure 2.
The sensor's function is to convert the electrostatic field formed by the flow of powdered materials into an electrical signal through electrostatic induction, which is then transmitted to the transmitter via cable.
The transmitter is composed of a multi-channel board, with its output being an analog current and an optical and acoustic display that varies with the measured powder content. The new meter outputs a 4-20mA current signal, alarm switch quantity, or data signal through the RS485 interface. During normal operation (i.e., no bag breakage, powder content not exceeding the limit), the HDLBJ-7 model meter displays all green lights on and red lights off, and outputs the analog current value. The current values output by each channel are measured by an automatic inspection and manual point selection system composed of a single-chip microcomputer. The device can operate in either "Automatic Inspection" or "Manual Point Selection" modes as required. The "Box Selection" key serves as a switch to toggle between "Automatic" and "Manual" modes and, in manual mode, as a switch to switch between box measurements.
Section 3: Technical Specifications of Bag Dust Removal Leak Detector
Dust concentration measurement range: 0-1000 mg/m³.
2. Test Tube Diameter: 0.1-3m
3. Measured Particle Size: 1-80 μm
4. Sensor measurement point temperature allowance: <260℃. (High-temperature models can be custom-made according to on-site temperature.)
5. Sensor measurement pressure range: 2.0 MPa.
Sensor insertion depth: 300mm (total pipe length 1200mm). (Available for special customization according to site pipeline size.)
7. Instrument operating environment temperature: -30 to 80°C.
8. The transmitter housing dimensions are: 430×530×200mm
4. Sensor Installation Point Selection
5. Sensor Installation and Wiring Methods
Section 6: Sensor Connection Methods
