I. Overview of Bag Filter Leak Detector
With the advancement of industrial automation and the increasing emphasis on environmental protection, the monitoring of industrial dust has become increasingly stringent. Our developed bag dust removal on-line monitoring instrument is an effective on-line monitoring device that checks for bag damage in dust collectors and the dust content in each chamber. It can accurately and promptly detect and prevent the emission of harmful dust and reduce the loss of valuable powder, 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 removal bag house.
This instrument is widely used for leak detection in dust collection systems in metallurgy, power, chemical industry, food processing, building materials, and wood processing industries. When used for leak detection in dry ash removal systems 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 positive pressure ash removal and dust-powder separation due to bag damage. Particularly valuable in the ironmaking process, where blast furnace gas dust collectors, which are highly toxic (with CO content close to 30%) and operate at positive pressure, this instrument offers unique practical benefits. Over the past decade, it has been used from small furnaces to large ones (up to 2500 M³), from single trial installations to multiple installations (with some manufacturers installing multiple units). Through production practice across various manufacturers, it has proven to be sensitive, reliable, with minimal maintenance, highly practical, and capable of 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 promotion and use.
The HDLBJ-7 Bag Dust Collector Leak Detector comes in two series. One series allows for simultaneous online detection of the operating conditions of up to 8, 10, or 12 bag dust collector enclosures. This series features computerized patrol inspection, overload indicator lights, sound alarms, and a 4-20mA analog current indicator as well as switch quantity output. The other series not only monitors the operating conditions of the dust collector enclosures online but also comes with a main pipeline concentration meter, enabling real-time online monitoring of the dust concentration in the main pipeline. The instruments in this series display the dust concentration values of each bag dust collector enclosure and the main pipeline on an LCD screen, and are equipped with dust overload alarms and sensor failure alarms. Additionally, they can output 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 range of applications (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 II: Principle of Bag Dust Removal Leak Detection Instrument
In flowing powdered materials, particles can generate static charges due to friction and collisions with each other, with the tube wall, or with dust bags. This creates a static field, whose changes reflect the variation in dust content. A leak detector measures these changes in the static field to assess the proper operation of the dust bag filtration system. When a dust bag ruptures, the dust content in the gas-solid two-phase flow within the pipeline increases, along with an enhanced static field intensity.
This set consists mainly of three parts: ①Sensor (signal collection section), ②Transmitter (signal processing section), and ③Signal Transmission. The principle block diagram 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 powders into an electrical signal through electrostatic induction, and then transmit this signal to the transmitter via a cable.
The transmitter is composed of a multi-channel board, with its output being an analog current and optical audio 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, while outputting the analog current value. The current values output by each channel are measured by an automatic patrol and manual selection system composed of a single-chip microcomputer. The device can operate in either "Automatic Patrol" or "Manual Selection" modes as required. The "Box Selection" button serves as both the switch for toggling between "Automatic" and "Manual" modes and as the switch for toggling the box measurement in manual mode.
Section 3: Technical Parameters of Bag Dust Collector Leak Detection Instrument
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 allowable temperature: <260°C. (Special high-temperature models available upon site temperature.)
5. Sensor measurement pressure range: 2.0 MPa.
6. Sensor insertion depth: 300mm (total pipe length 1200mm). (Available for special customization according to on-site pipeline size.)
7. Instrument operating environment temperature: -30 to 80°C.
8. The transmitter enclosure dimensions are: 430×530×200mm
Section 4: Installation Case Studies Shared Below:
