Fault phenomenon and its causes and solutions:

1. Air purification device: including a flow meter, two glass tubes, an air pump and connection hose.

(1) Flowmeters: The inlet and outlet ports of the flowmeter may be blocked by the silica particles in the drying tube due to the connection to the drying tube, so that the gas flow rate may not be stabilized, or the specified flow rate may not be adjusted; if the interior enters the liquid or enters The combination of dust and moisture will cause a large resistance to the small float, which will also cause the flow to be unstable or unable to adjust; its own damage, such as the internal air tightly closed, the needle valve also causes the flow to be unadjustable or unstable.

(2) Glass tube: The lower ends should be filled with deesterified cotton. The two upper and lower air holes are shielded so that their contents do not inhale into the connecting pipe, blocking the air path. If it has small cracks, it can be sealed with special glue. Once the silicone is completely discolored, it must be replaced in time.

(3) Air pump: The principle is that the interior is driven by electromagnetic action to move the two cups back and forth to produce aerodynamic force. Its failure is usually caused by the rupture of two cups. When the cup breaks, the pumping force drops, showing that the flowmeter floats down and the flow rate is unstable, which is the same as that of the 1 and 2.

(4) Rubber tube: It is prone to aging, causing system air leakage and unstable flow.

The performance of the above failures are the same. The leak detection work for each test is for them (of course, also including the electrolytic cell) reflected in the sample results are to make the measurement results unstable, ups and downs.

2 electrolytic cell (1) The upper cover of the electrolytic cell should be tightened, the aging of the sealing ring, and the plastic opening at each access hole is the cause of air leakage.

(2) Four pole pieces in the electrolysis cell, two small ones, two large groups of indicating electrodes, which are the electrolysis electrodes. The indicator electrode serves to sense the titration of the electrolyte and to control the titration of the electrode. If any electrode goes wrong, it will cause the experiment to fail. Therefore, it must be ensured that the surface of the four pole pieces is clean, and no cracking may occur at the seal.

If the electrode pad is instructed to be disconnected from its lead (such as when the sealer cracks), the electrolytic electrode will continue to be electrolyzed and cannot be stopped. The electrolyte is red, and the screen is counting rapidly (even if the coal sample is not put). The phenomenon of sticking on the surface is also such a phenomenon: if the electrode plate is disconnected from its lead, the electrolyte will become more and more white during sample preparation, but the screen is not Counting, that is equivalent to the electrolytic switch off state. The surface fouling is manifested as delayed electrolysis, that is, the electrolysis suddenly turns on when the liquid is very white, and the measurement result is seriously low and unstable.

Treatment method: The surface of the dirty, can be cleaned. If the split rubber is disconnected, the residual glue may be removed, the plastic pipe connected with the pole piece is removed, the inner wall thereof is cleaned, the eroded lead part is replaced, the re-soldered part is re-welded, and the sealant is not glued. The electrolyte may have accumulated inside, the leads have been corroded, and the pole pieces are not conducting.

(3) Leads of electrolytic cell outlets and sockets on the machine, as a result of the long-term oxidation, loosening caused by the same phenomenon as the pole piece is contaminated or open circuit, the plug can be plated with a thin layer of solder, remove the oxide layer to increase the plug and The tightness of the socket can also be directly welded to the corresponding point in the machine.

3 mixers:

The principle is to use a rotating magnetic field to drive the magnetic stir bar in the electrolytic cell to rotate. If the stirrer's magnetic field is weakened or its motor speed is slowed, the stirring speed is correspondingly slowed down. The disappearance of the magnetic force of the stir bar is a common cause of the stirring out-of-step phenomenon, which can be replaced or magnetized. The faster the stirring speed, the more favorable the uniform titration of SO2 hydrate. The reason why the stirring speed is too low and the measurement result is unsatisfactory is that if the stirrer is stopped in the experiment, the electrolysis phenomenon will occur.

4 burner section:

(1) The correct installation of the thermocouple is very important. When it is dropped back to the silicon carbon tube, it will fall back to 2mm. The farther away from the instrument, the lower the display value of the instrument is, the lower the actual furnace temperature is, the less the set temperature (actual furnace Temperature has already reached) or rise to set °C, the control accuracy is not good, dozens of fluctuations in the temperature control point or even Baidu fluctuations: If the thermocouple hits the silicon carbon tube, when it rises to high temperature, there will be leakage The current enters into the machine from the silicon carbon tube, which causes the display temperature to fluctuate greatly, and the straight line goes down and even appears negative temperature (negative temperature difference from the temperature drop caused by the return of the thermocouple), which severely damages the temperature of the instrument. . Abnormal temperature control, furnace temperature is too high (above 1050 °C) phenomenon is: Look inside the furnace, is not a normal red light, but has been bleached, often causing adhesion of quartz boat and reducer, serious The reducer burns, and the reducer sticks to the silicon carbide tube. If the coal sample is fed, the coal ash will be found on the porcelain boat when it is withdrawn and it will not be scraped off. The thermocouple position or adjustment can be adjusted according to the actual situation. Set the temperature. If the thermocouple is not connected properly or its internal disconnection, the desulfurizer displays 1 to indicate over-range: if the thermocouple is short-circuited, the instrument always shows room temperature.

(2) The reducer is a closed combustion chamber of the sample, ensuring that the SO2 gas generated by combustion enters the electrolytic cell under the action of the air pump. If it cracks or breaks, it will cause the escape of sulfur-containing gas, which will make the measurement result seriously low and unstable. The different-diameter tube will be hidden under the high temperature and concealed in the furnace body. Therefore, the fracture is hidden, and when it is abnormal, it can be released. Bolt fastening screws at the mouth and take it out for inspection.

(3) 10 Ω is the best value for silicon carbon tube debugging. If the resistance is too large or too small, the maximum heating current will be reduced, and the natural resistance will increase. The performance is that the heating time becomes longer or rises than the set temperature: At this time, the furnace flow simulation display lamp cannot reach the 9 or 10 light position. The treatment method is generally replaced by good, and the resistance value can be measured when determined.