Classification of methanol extraction towers? Urgent discussion
Thread Content
Friends are currently discussing the classification of this tower. It is a methanol extraction tower with a design pressure of 1.68 MPa and a design temperature of 70 degrees; its operating pressure is 1.5 MPa and its operating temperature is 50 degrees. The medium used is C3 and C4 compounds, which are flammable. The volume of this tower is 37.5 cubic meters. The design institute has classified it as Category 2. Is this correct?
Are there any issues with classifying medium voltage as category two? Do you mean three categories? Then you need to first figure out whether this device is a reaction vessel or a separation vessel.
The key is this issue – does Wen Bing have any suggestions?
Extraction is a unit operation used to separate mixtures by taking advantage of the different solubilities of components in a solvent. There are two types of extraction: liquid-liquid extraction, which involves using a selected solvent to separate a certain component from a liquid mixture; the solvent must be immiscible with the liquid mixture being extracted, possess selective solvating capacity, as well as good thermal and chemical stability, and have low toxicity and corrosivity. Using benzene to separate phenols from coal tar ； Separate olefins and the like in petroleum fractions using organic solvents. Solid-liquid extraction, also known as leaching, uses a solvent to separate components within a solid mixture; for example, water is used to extract sugars from beets ； Soak soybeans in alcohol to extract soybean oil and increase oil yield ； The process of extracting active ingredients from traditional Chinese medicines using water to produce an extract is called \"percolation\" or \"leaching\". Although extraction is often used in chemical experiments, its process does not cause any changes to the chemical composition of the substance being extracted (in other words, no chemical reactions occur), so extraction is a physical process. According to the extraction process, it is a physical separation process; therefore, classifying it as such should be correct. It’s just that some colleagues in our unit have doubts. The relevant regulations don’t specify this clearly, and they insist on their own opinion regarding classifying it as category three, which really confuses me.
Since it is a separation process, it involves a separation container; it belongs to category two, not category three. What are the questions from the people in your organization? Do they think there is a chemical reaction taking place?
The basis for the questions raised by our colleagues is Annex 1 of the regulatory standards, which provides an explanation of pressure vessels used in reactions; such vessels are primarily employed for carrying out physical and chemical reactions of the substances contained within them. Extraction is also considered a physical reaction.
What is referred to in tolerance specifications is chemical reaction, and any chemical reaction inevitably involves physical changes as well. Simple physical changes cannot be taken into account