Corrosion Resistance Requirements of Field Instruments in Fine Chemical Production
In fine chemical production, field instruments are exposed to various highly corrosive raw materials and media. To ensure the normal operation and service life of the instruments, extremely high requirements are placed on their corrosion resistance. For example, certain chemicals may corrode the metal components of the instruments, leading to decreased performance or even damage. Therefore, when selecting instrument materials, materials with good corrosion resistance, such as metals like titanium and tantalum, or non-metallic materials like polytetrafluoroethylene, need to be chosen. At the same time, technologies such as coatings and film deposition can be used to add protective layers to the instruments to enhance their anti-corrosion ability. For instance, in some strongly acidic and alkaline environments, the use of special anti-corrosion coatings can effectively protect the instruments from corrosion. Additionally, conducting regular anti-corrosion maintenance and inspections of the instruments and promptly discovering and addressing corrosion issues are also important measures to ensure the corrosion resistance of the instruments.
Requirements for Field Instruments in Fine Chemicals to Adapt to High Temperature and High Pressure Environments
Fine chemical enterprises often operate under extreme conditions, and high-temperature and high-pressure media are common. This requires that field instruments have strong pressure resistance and high-temperature resistance capabilities. For example, in high-temperature environments, the components of the instruments may deform due to thermal expansion, affecting measurement accuracy and reliability. Therefore, the materials of the instruments need to have high thermal stability and a low expansion coefficient. At the same time, the sealing structure of the instruments also needs to be able to withstand the pressure brought by high temperatures and high pressures to prevent medium leakage. In practical applications, like some instrument components made of special alloys, they can maintain stable performance under high temperatures and high pressures. Moreover, to ensure the accuracy of the instruments under extreme conditions, strict high-temperature and high-pressure tests and calibrations are also necessary.
Principles for Selecting Field Instruments in Fine Chemicals
When selecting field instruments in fine chemicals, several important principles need to be followed. First, it must meet the process requirements, and the type and specification of the instrument are determined based on factors such as process parameters, medium properties, pipeline diameters and materials, and environmental conditions. Secondly, scientificity should be considered, finding a balance between advancement, economy, and operating costs. For example, for key detection points and control systems, more advanced and higher-precision instruments should be selected; for some non-critical parts, cost-effective instruments can be chosen on the premise of meeting the basic requirements. Furthermore, it is necessary to ensure the uniformity of the selection. For larger engineering projects, products of the same series, the same specification and model, and the same manufacturer should be selected as much as possible to facilitate later maintenance and management. Finally, it is necessary to ensure that the selected instruments are market-verified, reliable in performance, and have sufficient supply to avoid affecting the project progress due to instrument supply issues.
Selection of Instrument Manufacturers in Larger Fine Chemical Engineering Projects
In larger fine chemical engineering projects, the selection of instrument manufacturers is crucial. On the one hand, the reputation and word-of-mouth of the manufacturer should be considered, and manufacturers with good market reputation and rich experience should be selected to ensure product quality and after-sales service. On the other hand, the technical strength and innovation ability of the manufacturer should be investigated, being able to provide technical solutions that meet the special needs of the project and are constantly updated. For example, some manufacturers may have unique advantages in the research and development and production of specific types of instruments, and can provide more accurate and stable instrument products for the project. In addition, attention should also be paid to the production capacity and supply cycle of the manufacturer to ensure that the required instruments can be provided on time and in full to avoid affecting the project progress due to supply delays. At the same time, good communication and cooperation with the manufacturer is also one of the key factors for successful selection.
Requirements for Installation Positions of Field Instruments in Fine Chemicals
The installation positions of field instruments in fine chemicals need to meet a series of strict requirements. First, they should be easily accessible, observable, repairable, and operable. If necessary, dedicated operation platforms and ladders should be set up to facilitate daily maintenance and fault handling by staff. Secondly, they should avoid places with high temperatures and strong vibrations to prevent these adverse factors from affecting the accuracy and stability of the instruments. Furthermore, they should avoid electrostatic and electromagnetic interference. When it is impossible to avoid, appropriate anti-static and electromagnetic interference measures should be taken to ensure the accuracy of the instrument measurement data. In addition, for non-waterproof instruments installed outdoors, they should be installed in instrument protection boxes to prevent erosion from external factors such as rainwater. Finally, when non-explosion-proof instruments are used in explosion-hazardous locations, they should be installed in positive pressure instrument cabinets or take other explosion-proof measures and comply with relevant explosion-proof regulations to ensure production safety.
Requirements for the Connection of Field Instruments and Process in Fine Chemicals
The connection of field instruments and the process in fine chemicals needs to meet various requirements. The material at the process connection of the instrument should not be lower than that of the pipeline or equipment at the process connection to ensure a strong and durable connection. The pressure grade at the process connection of the instrument should also not be lower than that of the pipeline or equipment at the process connection to prevent problems such as leakage due to pressure mismatch. Unless otherwise specified in the design, the nominal pressure of the process connection flange of the measurement instrument for toxic and flammable media should comply with specific standards. For example, for grade A pipeline flanges, the nominal pressure should not be lower than 5.0 MPa; for grade B and C pipeline flanges, the nominal pressure should not be lower than 2.0 MPa. In addition, in steam, air, and water pipelines with a design pressure of not more than 0.6 MPa, the nominal pressure of the flange should not be lower than 1.0 MPa. At the same time, the selection of gaskets for flange sealing should also comply with the regulations, and appropriate gasket types, such as asbestos rubber sheet gaskets, polytetrafluoroethylene-coated gaskets, wound gaskets, or metal ring gaskets, should be selected based on different pressure and medium conditions.
Requirements for Display Accuracy of Field Instruments in Fine Chemicals
The display accuracy of field instruments in fine chemicals is crucial for the monitoring and control of the production process. To ensure display accuracy, high-precision sensors and advanced signal processing technologies need to be adopted in the design and manufacturing process of the instruments. For example, the use of sensors with high sensitivity and good linearity can perceive changes in the measured parameters more accurately. At the same time, the calibration and debugging of the instruments are also very critical, and multiple calibrations need to be carried out under different working conditions to eliminate errors. In actual use, conducting regular maintenance and verification of the instruments and promptly replacing aged or damaged components can ensure that the instruments maintain accurate display for a long time. In addition, for some measurements with extremely high precision requirements, multiple measurements and comparisons are also needed to improve the reliability of the measurement results.
In conclusion, fine chemicals have strict requirements for field instruments in terms of corrosion resistance, adaptation to high-temperature and high-pressure environments, selection, manufacturer selection, installation positions, connection with the process, and display accuracy. Only by meeting these requirements can the instruments play the role of accurate monitoring and control in fine chemical production, ensuring the safe, stable, and efficient operation of production.