INSTRUMENT AND METHOD FOR MEASURING THE CONCENTRATION OF UNBURNED CARBON PARTICLES LOCATED IN THE INNER PORTION OF STEAM GENERATOR FURNACES.

摘要

Described herein is an instrument for measuring the concentration of unburned carbon particles located in the inner portion of steam generator furnaces (1200 degree C to about 1600 degree C) of thermoelectrical central stations and industrial heaters using fuel oil, heavy crude oil, pulverized carbon or oil coke. The inventive instrument is characterized in that it comprises three stainless steal concentric tubes having a length of from about 1 m to about 6 m; an S-type pitot tube, having the same length as that of the aforesaid tubes, is located between the outer tube and the intermediate tube. The tubes are welded together by the end portions thereof, thereby forming a single structure having a diameter smaller than that of a heater furnace spyhole; the outer tube comprises both pitot tube inlets and a nozzle for suctioning combustion gases disposed at the end portion of the instrument that is inserted into the furnace, the nozzle having a minimum diameter of 3/8 and a maximum diameter of 5/5. Th e instrument comprises a cylindrical-shaped case located at the end portion opposite the gas entrance which is heated at a temperature of up to 150 degree C by an electrical tape, the case simultaneously including a glass fiber filter where the particles are collected. The water flow for cooling the instrument is from about 1000 liters to about 1500 liters per each insertion meter, at a pressure of from about 7 kg/cm3 to about 10 kg/cm3, and at a temperature of from about 60 degree C to about 70 degree C. The inventive instrument is horizontally introduced into the furnace through a spyhole, the first reading being taken at a distance of 0.5 meters away from the inner wall, subsequent readings being taken with insertion increments of 0.5 meters until one half of the transversal section of the furnace is covered. The instrument is simultaneously or alternately introduced into the opposite side wall for performing the analysis of the whole furnace transversal section. An average value of the differential pr essure indicated by the S-type pitot tube is taken at each point; the speed is predetermined by the aforementioned value and gas density (temperature is measured by a suction pyrometer); the gases are suctioned using a vacuum pump at said predetermined speed. The collected particles are dried and weighted, the concentration being determined according to the suctioned gases. Finally, a particle analysis is performed with regard to their size distribution and chemical composition (carbon, hydrogen, nitrogen, sulphur and ashes).