This paper deals with the development of an isokinetic dust sampler based on the principle of balancing of two differential pressures; one is of flue gas in a duct measured by a Pitot tube and the other of the sampling gas measured by a suction nozzle disposed behind a dust filter. Both differential pressures are led to each pressure transducer and connected to a pressure regulator, which transmits the electronic signals gained by changes of the dynamic pressure of flue gas to a servovalve. So the device has made the isokinetic procedure by the sampling apparatus automatic.
The apparatus consists of five parts; a sample dust collector with a suction nozzle and a Pitot tube, a gas cleaner, two pressure transducers, an automatic controller and a gas suction pump.
The characteristics of the suction nozzle and the automatic sampling apparatus have been studied in the test wind tunnel, and the applicability to source sampling has been affirmed.
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