Introduction to the requirement of centrifuge nitrogen protection explosion protection

Centrifuge very wide application, such as chemical, pharmaceutical and other industries in many areas of the national economy, which is still the current chemical intermediates, pharmaceutical raw materials, medicine and other production processes in solid-liquid separation of the main equipment. Due to the different physical and chemical properties of the applications, processes and media used in centrifuges in these industries, there are different requirements for centrifuges, such as material requirements, structural requirements, anti-corrosion requirements, and explosion-proof requirements.

This paper mainly introduces the design of a nitrogen protection explosion-proof system for the application of digital oxygen oximeter in the application of centrifuge in the chemical and pharmaceutical industry.

2 explosion-proof requirements

We know that the three elements that generate explosions are temperature, fire source, oxygen, and the simultaneous existence of three basic conditions to prevent chemical explosion. It is the basic theory for preventing chemical explosion of combustible materials. In other words, the essence of all technical measures to prevent chemical explosion of combustible materials is to prevent the simultaneous existence of three basic conditions of chemical explosion. Among them: (1) temperature, for a specific medium, whether it is liquid phase or gas phase, the operating temperature of the centrifuge should be considered in the process design, which depends mainly on the process conditions, and will not be elaborated here; (2) Fire Source, in the design of the centrifuge, the application of sufficient safety air- rotor pump room for moving parts to eliminate the possible mechanical friction and impact, at the same time, the machine must have measures to eliminate static electricity. For brake devices, mechanical friction brakes should not be used, generally in the form of electrical energy brakes (non-contact brakes, the disadvantage is that the brake time is longer than the contact type, especially when fully loaded) This is especially true in the case of large inertia.) In addition, for the transmission belt, the anti-static belt is used to eliminate or reduce the possibility of static electricity generation; (3) oxygen is generally protected by inert gas, and the oxygen concentration is maintained by replacing the inside air with nitrogen inside the centrifuge. Within the safe range.

3 explosion-proof measures

At present, the nitrogen protection of the centrifuge generally used is actually only a nitrogen gas inlet pipe and a nitrogen gas outlet pipe are arranged on the casing, and the inner cavity is filled with nitrogen gas when the centrifuge is working. As to whether the nitrogen concentration can reach the safe range, there is no quantitative control, and therefore, the reliability of the nitrogen protection is poor. An improved nitrogen protection system is designed with an online oxygen detection device and a pressure transmission sensor to detect the oxygen concentration in the centrifuge chamber during operation, and to perform quantitative control to control the oxygen content within a safe range (also That is to say, the oxygen concentration in the machine is outside the explosion limit of the flammable and explosive medium).