Pressure issues in hydrochloric acid synthesis furnaces
Thread Content
This post was last edited by sunjl1981 on 2013-1-6 at 19:57. If the chlorine pressure in the hydrochloric acid synthesis furnace increases, why does the pressure inside the furnace show as negative? # + + .
This phenomenon is likely due to an excess amount of hydrogen during normal operation; the absorber absorbs hydrogen chloride selectively, and this excess hydrogen increases the load on the exhaust gas extraction system, resulting in higher pressure in the synthesis system. As the chlorine pressure rises, its proportion entering the furnace increases accordingly. When the ratio of chlorine to hydrogen is close to 1:1, the excess hydrogen amount is also close to zero, at which point the absorber almost completely absorbs the syngas, so there is very little exhaust gas and the furnace pressure drops； If the chlorine pressure continues to rise, it will lead to an increase in the amount of chlorine entering the furnace, resulting in an excess of chlorine and excessive free chlorine in the product acid; therefore, regulation and control are necessary.
The friend upstairs is right; I would like to add that regarding the pressure involved in hydrochloric acid synthesis, two other factors need to be taken into account: moisture content and impurities in the raw materials, as well as crystallization blockages in the pipes.
I would like to add one more point: should we also consider the purity of chlorine at the scene at that time?
I completely agree. When the pressure stabilizes again, the furnace pressure should stabilize as well. The control system for the synthesis furnace mentioned by the poster is manual, right?
The poster is quite observant regarding the production process; sometimes, during operation, chlorine reacts with all the excess hydrogen, causing the furnace pressure to drop； If there is an excess of chlorine, the free chlorine content in the product will be too high. It should be noted.
The answer above is quite accurate; given a constant pumping force from the water jet pump, the pressure in the system depends on the amount of gas that has not been absorbed by the pure water. In normal furnace operation, there is an excess of hydrogen. By increasing the amount of chlorine at this time, the reaction between hydrogen and chlorine becomes more thorough, which reduces the amount of gas that remains unabsorbed, thereby lowering the system pressure.