Laboratory hydrogen analyzer analysis principle - Database & Sql Blog Articles

Analytical principle: The coal sample is burned and decomposed in a purified oxygen stream at a high temperature of 850 ° C to convert hydrogen into water and carbon to carbon dioxide. The reaction is as follows: the water and carbon dioxide produced by the combustion are passed under the oxygen stream. In the platinum inner wall electrolytic cell coated with phosphorus pentoxide, when the anhydrous gas passes, the electrolytic cell is nearly infinite, and there is no open current between the positive and negative electrodes. When the gas containing water passes through the electrolytic cell, the water Immediately absorbed by phosphorus pentoxide, the formation of metaphosphoric acid, the equation is as follows: At this time, the internal resistance of the electrolytic cell is reduced, the current flowing through the electrolytic cell is gradually increased, and the reaction is generated by electrolysis as follows: the maximum current flowing through the electrolytic cell is not less than 500 mA. As the electrolysis progresses, the amount of metaphosphoric acid decreases, and the electrolysis current also decreases. When the end current (60 mA) is reached, it means that the electrolysis has ended, and the amount of electricity consumed in the electrolysis process is measured, and the law of Faraday can be applied. Calculate the mass W of the substance to be tested. Where: F: the value of the Faraday's law constant is 96,487 coulombs; M: the molar mass of the substance to be tested; n: the number of electrons transferred to the electrode reaction material; i: the electrolysis current; t: the electrolysis time. Because the instrument is based on Faraday's law, using Coulomb integrator, using quantitative technology and computer control, it can directly display the milligram of hydrogen mass. The printer prints three hydrogen values. G (mg), the percentage of various hydrogen values ​​can be calculated as follows: where: W: instrument hydrogen display number; (mg) G: sample weight; (mg) Mad: analysis of coal sample moisture Value; %0.

1119: The water is converted into the coefficient of hydrogen. After the water is absorbed by the electrolytic cell, the carbon dioxide is absorbed by the absorbent alkali asbestos to form sodium carbonate and water, and the reaction is as follows: then the carbon analysis base Cad and the dry basis Cd are calculated according to the weight gain of the absorbent. The percentage content is as follows: where:: U-tube weight gain for absorption of carbon dioxide, (mg) (first plus two); that is (weight after suction - weight before suction) + (weight after suction - weight before suction) ); Mad: analysis of the moisture value of the coal sample; G: is the weight of the sample; (mg) 0.

2729: The coefficient of carbon dioxide converted into carbon; 2. The principle of program control The whole process of the instrument is controlled by microcomputer. After the instrument is connected to the power supply, the date, sample weight and hydrogen blank value are input through the keyboard, and the moisture value of the sample is analyzed. Press the hydrogen measurement button. When the carbon is to be measured, press the carbon test button. The motor rotates forward, and the sample feed rod is pushed forward to advance the sample. When it is pushed to 300 °C, the sample feeding mechanism touches the micro switch. This signal is sent. Into the computer, the microcomputer stops the motor, and delays for 30 seconds, then enters 500 °C, the sample feeding mechanism touches another micro switch, the signal is sent to the computer, the microcomputer stops the motor, and delays 2 Minutes, then the computer sends a signal to make the motor rotate forward to drive the sample rod to continue to advance the sample, push it to 800 °C, the sample feeding mechanism touches another micro switch, the signal is sent to the computer, and the microcomputer stops the motor. Turn, and delay for 10 minutes, then send a signal to reverse the motor, drive the sample rod to pull the quartz boat containing the sample out to the original position, the motor stops, the alarm alarms to indicate the test The whole process is over, the printer