Regarding the variable frequency speed control of SO2 fans
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Variable frequency speed control of motors in equipment such as fans and pumps is widely used, but it seems that its application in SO2 fans in large-scale acid production plants, especially those that use flue gas for acid production, is not yet widespread It is also the case that frequency converters are mostly used in small and medium-sized installations for technical upgrades; whereas devices of slightly lower importance are more frequently used in larger installations. For low-load operation, using frequency converters is highly beneficial for saving energy and reducing consumption; yet why do design institutes choose them less often for SO2 fans? Is it everyone’s fixed mindset? Is it the construction party that is reluctant to spend this amount of money? Or is it that everyone’s equipment is operating at full capacity, and low-load conditions are rarely considered? Still, modern fans generally maintain high efficiency even at low loads; isn’t their power consumption not much higher than that of inverters? Additionally, how much energy can be saved by using an inverter? Could you provide a rough figure?
If you search on forums, you’ll find many posts on this topic; frequency conversion is used in the sulfuric acid production industry from pyrite, and it is currently primarily applied to feed belts and fans located in front of the furnaces. The number of converted main fans is very small, and there are two main reasons for this. First, the main fans in 100,000-ton systems generally have a power rating of around 700 kilowatts, and inverters for them are quite expensive, costing around millions of yuan. 2. The surplus capacity of the main fan used for acid production from pyrite is generally not large. When the system is operating at full capacity, little adjustment is needed; the inlet and outlet valves are sufficient to meet the requirements.
The same is true for hydraulic couplings; the use of couplings with blowers is quite common in the sulfuric acid industry.
Frequency conversion also incurs costs, and its adjustment range is not infinite. As far as is known, some types of inverters tend to become less efficient under light load conditions. Another point that everyone should pay attention to is the issue of crossing the surge zone during variable frequency regulation; therefore, even when a variable frequency drive is installed, a circulation valve for the fan is still necessary. This post was last edited by in the blink of an eye on 2009-4-10 08:15]
The S1200 fans used in our sulfur-based acid production process are equipped with variable frequency drives, which make it very convenient to adjust the air volume, especially when the system temperature rises or the load decreases
The design by Nanhua Design Institute is good and can be applied
Haha, this time my fan (S1200) had a minor issue with its variable frequency function; it was operated at the standard frequency for over 30 hours, and the effect was quite noticeable – there was a difference of around 3000 KW in power consumption per day.
Variable frequency drives should help save a significant amount of energy. We have a 630KW fan that we plan to install; sometimes, in order to increase production, extra capacity is considered when selecting such fans. Installing a variable frequency drive would be a good option. The cost is around 800,000 yuan, and the manufacturer has agreed to allow payment in installments based on the amount of energy saved each month.