Research On Ignition Source Detection And Alarm In Dust Collector Pipe

In recent years, the dust explosion, caused by the ignition source mixed from dust collector pipe, is increasing more and more. The dust explosion is extremely destructive and involves a wide range of industries, it has occurred in coal industry, chemical industry, metal processing industry, food and feed processing industry and so on. Therefore, the research on ignition source detection and alarm in dust collector pipe is of great research significance and quite high application value. The ignition source in dust collector pipe is small, low heat and moving fast, so the only way to detect it is using non-contact detection method. In this subject we use PbS infrared detector building the ignition source detecting system, and identify the ignition source by detecting the infrared radiation issued by the ignition source.In this paper, we build the mathematic model of the detector on pipe receiving the radiation power from the ignition source and use MATLAB to compute and analysis the impact of the ignition source’s temperature, diameter, speed and other factors to the detector’s receiving radiation power.Because the infrared detector’s window is small and has a limited receiving range, its sensitivity is low, so we design the optical part to expand its receiving range and increase its sensitivity.The hardware circuit of system is designed, which includes analog signal acquisition circuit and digital signal processing circuit. The analog acquisition circuit includes a bias circuit, an amplifier circuit, a precise full-wave rectifier circuit and a low-pass filter circuit, etc. The digital signal processing circuit uses MSP430microcontroller for data acquisition and data procession, it also has keyboard, LCD, serial communication interface and so on. Its software mainly includes data acquisition, data procession, display and RS-232communication. We realize the automatic acquisition of signal, RS-232communicaiton, LCD display and keyboard operation.The overall building and debugging of the system is completed in this design, and we make some preliminary ignition detection experiments in the laboratory and test the system detection performance, simulating the ignition source and pipe environment and building the ignition source detection apparatus. The experiments show that the system is of fast response and reliable detection to the ignition source, simulated by the5mm diameter steel ball whose emissivity is about0.8, and the ignition source temperature range that the detection system can detect in different distances is given according to the experiments.