What are the negative effects of the acid temperature in the upper section of the absorption tower being higher than 90°?
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Our factory is a newly built sulfuric acid production facility that uses the contact process to produce acid at an annual capacity of 120,000 tons. Initially, there were two acid circulation tanks; now they have been replaced by two absorption circulation tanks (where there was originally just one absorption circulation tank) plus one drying circulation tank. In the past, the temperature of the acid never rose above a certain level, but now the temperature of the acid in the upper tower of the second absorption stage is 106 degrees, while the temperature in the returning stream is 117 degrees. The current consumption of the circulation water pumps is normal, the water valves of the acid coolers are fully open, and the bypass valves for the acid flowing through the acid coolers are fully closed. Yet the situation remains the same. What could be the reason? Please give me your guidance~~~
What are the water temperatures at the inlet and outlet of your acid cooler? Check to see if the heat exchange efficiency has decreased
Stop the machine immediately to clean the acid cooler; I suspect that smoke is already coming out of the exhaust tower, and the liquid has taken on a white, acidic color. It is recommended to install a filter at the inlet of the circulating water – this can be designed by oneself
It will accelerate the corrosion of the equipment, and it will also cause foam in the exhaust gases as well as poor absorption.
Check the flue gas temperature at the second inlet; in our plant, a value above 160° is considered high. Another thing is to control the acidification properly and avoid adding water as much as possible.
1. Check the current of the circulating acid pump; if there is a problem with the pump, the amount of acid fed in cannot increase. 2. The acid cooler has poor heat exchange efficiency and needs to be cleaned. 3. Check the acid distributor to see if there is a problem with it.
The main negative effects are, first, increased corrosion, and second, an impact on absorption efficiency, with acid mist levels possibly exceeding limits.
If there are no temperature sensors on the circulating water pipes or if the sensors are damaged, an infrared thermometer can be used to take readings; if none of these options are available, manual temperature measurement will have to be employed. When using this method, it is necessary to take care to avoid burns (although the probability of such injuries is low).
Reply to 2# yi*aofei001 Hi! The tables are broken! An infrared scan showed that the temperature difference was around 10°C. I also opened one end of the acid cooler and checked; there was no sign of blockage. Since the purification system equipment in our factory often malfunctions, the water in the cooling tower becomes acidic, and tests with test strips showed an acidity level of 4···
Reply to 3# gaolei0993: There is no exhaust gas for now; the acid color will turn white once that happens. We have installed a spraying system on the acid return pipeline for the second absorption stage, but the temperature of the acid remains above 90° at present. It’s not clear which equipment might be damaged by this condition. If the temperature stays above 90°, how long before the equipment gets damaged?
Reply to 4# youwu: I wonder which devices the master can corrode? How long before symptoms appear...? What can be done to avoid it as much as possible~?