Potassium hydroxide is a kind of strong alkali, which is often used as chemical raw material. However, if the main content of the main product fails to meet the requirements when it is used, it will also affect the subsequent use effect. How to solve the problem when the main content of the product is low? Let's take a look.

　　主含量是指成品中KOH的質量分數，這是確定產品質量主要的參數之一，一般要求含量大于90%。這個過程中控制好堿液的溫度是關鍵。1.148%堿液濃度在經過一效、二效蒸發器蒸發只有，堿液濃度需要達到或大于48%，為后面進行的工序質量合格做好準備。這個過程主要是通過蒸氣冷凝產生的熱量用來蒸發堿液中的水分從而提高濃度，因此需要能夠保證蒸氣的壓力和溫度達到相應的要求：真空狀態下可以降低堿液沸點，所以為了節約能源和提升效率，蒸發器中的真空度要盡量保持一個比較高的狀態。二效蒸發器堿液真空度處于0.085~0.094MPa，溫度在75~85攝氏度之間，效果是比較好的。

　　The main content refers to the content of KOH in the finished product, which is one of the main parameters to determine the quality of the product. Generally, the content is more than 90%. In this process, the key is to control the temperature of alkali liquor. 1.148% of the alkali liquor concentration needs to reach or exceed 48% after being evaporated by the first and second effect evaporators, so as to prepare for the quality of the subsequent process. In this process, the heat generated by steam condensation is used to evaporate the water in the alkali liquor, so as to improve the concentration. Therefore, it is necessary to ensure that the pressure and temperature of the steam can meet the corresponding requirements: the boiling point of the alkali liquor can be reduced in the vacuum state, so in order to save energy and improve efficiency, the vacuum degree in the evaporator should be kept as high as possible. The vacuum degree of alkali liquor in the two effect evaporator is between 0.085 ~ 0.094 MPa, and the temperature is between 75 ~ 85 ℃.

　　1、提高高壓蒸氣的壓力和溫度

　　1. Increase the pressure and temperature of high pressure steam

　　升膜蒸發器以高壓蒸氣為加熱介質，可以繼續提高堿液的濃度，氫氧化鉀堿液溫度一般在190~210攝氏度之間比較適宜。

　　The rising film evaporator uses high-pressure steam as the heating medium, which can continue to increase the concentration of alkali liquor. The temperature of potassium hydroxide alkali liquor is generally between 190 ℃ and 210 ℃.
                        

　　2、氫氣燃燒爐及熔鹽系統

　　2. Hydrogen combustion furnace and molten salt system

　　濃縮制片過程需要使用熔融鹽HTS為加熱介質，而加熱BTS是使用氫氣燃燒爐來提供熱源的。燃燒爐提供的熱量要保證穩定，這樣才能確保熔鹽溫度和流量的穩定，才能生成足夠量的穩定熱量來加熱堿液，使經過濃縮器后的堿液溫度達到標準要求，一般在380-400攝氏度之間。

　　Molten salt HTS is used as heating medium in the process of concentrating and making slices, and hydrogen combustion furnace is used to provide heat source for heating BTS. The heat provided by the combustion furnace should be stable, so as to ensure the stability of the molten salt temperature and flow, and generate enough stable heat to heat the alkali liquor, so that the alkali liquor temperature after the concentrator can meet the standard requirements, generally between 380-400 ℃.

　　3、保持系統密閉

　　3. Keep the system closed

　　為了避免堿液溫度降低和發生潮解，降低其中的K0H含量，堿液在從濃縮器至片堿機的流動過程中需要盡量保持密閉狀態，避免和空氣進行接觸。

　　In order to avoid the decrease of temperature and deliquescence of lye, and reduce the content of k0h, the flow of lye from concentrator to flake caustic soda machine should be kept as closed as possible to avoid contact with air.

　　上面介紹的四種就是氫氧化鉀主含量低的解決方法，通過上面的方法處理之后可以有效的提高產品的純度。

　　The four solutions described above are the solution of low content of potassium hydroxide, which can effectively improve the purity of the product.