順酐，別名馬來酸酐，主要用于制造聚酯樹脂、醇酸樹脂，用于涂料、醫藥、油品添加劑，等等。那么，用雷達液位計對順酐儲罐進行液位測量，應注意哪些工況呢?
Maleic anhydride, also known as maleic anhydride, is mainly used in the manufacture of polyester resin, alkyd resin, coatings, pharmaceuticals, oil additives, etc. Then, what conditions should be paid attention to when using radar level gauge to measure the liquid level of maleic anhydride storage tank?
在化工廠，順酐儲罐有兩種，即精酐酐和粗酐罐，這兩種儲罐主要是圓柱形的拱頂罐，至于高度和直徑，有高6米，直徑6米的，也有其它尺寸的，具體要看自家工況情況。一般情況下，精酐儲罐的操作溫度大約為60攝氏度，粗酐儲罐的操作溫度則約為70攝氏度。
In the chemical plant, there are two kinds of maleic anhydride storage tanks, i.e. refined anhydride tank and crude anhydride tank. These two kinds of storage tanks are mainly cylindrical dome roof tanks. As for the height and diameter, there are 6m high, 6m diameter and other sizes. The specific conditions depend on your own working conditions. Generally, the operating temperature of refined anhydride storage tank is about 60 ℃, while that of crude anhydride storage tank is about 70 ℃.
以上是從儲罐角度而言的。接下來，再來看看順酐這種介質，在常壓的情況下，順酐的結晶點是52.8℃。60℃時，液體順酐的相對介電常數大約是50;20℃時，順酐呈固態，相對介電常數大約是2.1.
The above is from the perspective of storage tank. Next, let's look at the medium maleic anhydride. Under normal pressure, the crystallization point of maleic anhydride is 52.8 ℃. At 60 ℃, the relative dielectric constant of liquid maleic anhydride is about 50; At 20 ℃, maleic anhydride is solid and its relative dielectric constant is about 2.1
順酐在化工廠運行過程中，由于微量雜質(反應副產物)的存在，會有結晶出現。曾經有工廠使用過雙法蘭液位計和吹氣式液位計。結果由于結晶，都無法正常測量，且維護量大。
During the operation of maleic anhydride in chemical plant, there will be crystallization due to the existence of trace impurities (reaction by-products). Double flange liquid level gauge and air blowing liquid level gauge have been used in some factories. As a result, due to crystallization, it can not be measured normally, and the amount of maintenance is large.
同時，順酐也容易出現揮發，形成酐氣，酐氣有腐蝕性。也曾有工廠采用人工檢尺對液位進行測量，結果在有防護的前提下，皮膚黏膜仍有強烈刺激。
Meanwhile, maleic anhydride is also easy to volatilize and form anhydride gas, which is corrosive. There were also factories that used manual ruler to measure the liquid level. The results showed that under the premise of protection, there was still strong irritation to the skin and mucous membrane.
雷達液位計
Radar level gauge
鑒于這種情況的存在，有的廠子開始采用雷達液位計進行液位測量。投入使用后，發現測量效果很理想，而且維護成本也大大降低。從這個實例中，不難看出，雷達液位計可以測量順酐儲罐，但是什么樣的雷達液位計合適，還需要大家根據自家實際情況選擇。
In view of this situation, some factories began to use radar liquid level gauge for liquid level measurement. After putting into use, it is found that the measurement effect is very ideal, and the maintenance cost is greatly reduced. From this example, it is not difficult to see that the radar level gauge can measure the maleic anhydride storage tank, but what kind of radar level gauge is suitable still needs to be selected according to your own actual situation.
對于雷達液位計而言，順酐的介電常數雖不影響測量，但是揮發和結晶的情況，大家也應多加重視。
For radar level gauge, although the dielectric constant of maleic anhydride does not affect the measurement, we should pay more attention to the volatilization and crystallization.
