Solution for Online Monitoring of Oxygen Content in Reactor and Online Monitoring of Oxygen Content in Centrifuge

As a kind of industrial equipment, the reactor centrifuge is used in petroleum, chemical and other fields. Almost all of these industries have explosion-proof requirements for the reactor centrifuge. The safety of the centrifuge has become the primary concern of pharmaceutical factories.

As we all know, combustion requires three elements, combustibles, combustion aids, and ignition point. The essence of explosion protection is to control these three elements. As a chemically active gas, oxygen is also a very common combustion aid. In the petroleum, chemical, pharmaceutical and other industries, the reactor centrifuge feeds mostly flammable and explosive materials, so it is particularly important to control the oxygen content inside the reactor centrifuge. Need to analyze the oxygen content in the inner chamber of the reactor centrifuge How to measure the oxygen content in the process gas quickly, reliably and with low maintenance has always been an important topic. There are two methods for common measures in the industry.

One is the inert gas replacement method:

The method mainly ensures that the low oxygen content in the reactor is maintained by continuously injecting inert gas into the reactor. But this method also has another big limitation. Whether the concentration of inert gas injected into the reactor centrifuge can reach the safe range is not quantitatively controlled, and there is no clear value as the basis, and it is impossible to deal with various unexpected factors in the feeding. Therefore, the reliability of its protection is very poor.

The second is the oxygen content monitoring method:

By installing the reactor oxygen content online analysis system and the centrifuge oxygen content analysis system, the oxygen content in the reactor centrifuge can be monitored online in real time. The principle is to pump a certain gas from the reactor into the analysis instrument through the pipeline to monitor the oxygen content in the reactor centrifuge in real time, and the concentration alarm value can be set by itself. When the oxygen content reaches the alarm threshold, the analyzer will automatically alarm . Compared with the inert gas replacement method, the online analysis system for monitoring the oxygen content of the reactor has obvious advantages, which fundamentally solves the problem of monitoring the oxygen concentration inside the reactor. But the shortcomings are also obvious. This is mainly due to different industries and different manufacturers. The reactor centrifuge has different feeding and different parameters. It needs to be personalized and there is no universal. It is necessary to formulate corresponding pretreatment systems for different process parameters.

Such as the presence of corrosive gas and excessive water content in the gas in the reactor centrifuge, etc., it needs to be pre-treated before it can be monitored through the reactor oxygen content online analysis system. At present, this method is mainly used for supporting centrifuge manufacturers or terminal self-renovation.

Selection of reactor oxygen content online analysis system and centrifuge oxygen content analysis system:

There are usually many detection methods for oxygen content, such as traditional electrochemistry, ion flow, paramagnetic, zirconia, laser and other principles. Generally speaking, special working conditions are treated specially. The gas composition in the reactor centrifuge chamber is not complicated. For corrosive gas, strong acid and strong alkaline gas, a general electrochemical oxygen analyzer can be considered. The electrochemical principle has good versatility and low price. The disadvantage is that the sensor is not resistant to corrosion. It cannot be used directly when there is corrosive or acidic alkaline gas. The oxygen content analysis must be carried out after the pretreatment system.

When the gas composition in the centrifuge chamber of the reaction kettle is complex, there is acid gas (acetic acid), or alkaline gas or water vapor, etc., the oxygen analyzer using traditional methods such as electrochemistry not only requires a complicated pretreatment system, but also has a good effect. Relatively poor, magnetic oxygen analyzer or laser oxygen analyzer is generally recommended under such working conditions.

Because the paramagnetic oxygen analyzer uses physical principles (note: electrochemistry is a chemical principle) to measure oxygen content, only simple pretreatment is required, and it can be installed directly through pipelines. It is subject to acid gas and alkaline gas. And the influence of water vapor is small, and the oxygen content is directly monitored.

In addition to the electrochemical oxygen analyzer and the magnetic oxygen analyzer, there is also a laser oxygen analysis system. Like magnetic oxygen, laser oxygen uses optical principles to measure oxygen content. It is not sensitive to acidic, alkaline, corrosive and other gases. The disadvantage is that it requires the content of dust and other particulate matter in the measured gas.

Description of NK-100CY magnetic oxygen analyzer:

(1) The oxygen content adopts the principle of paramagnetic analysis;

(2) The measurement gas chamber is gold-plated and corrosion-resistant, with a unique grinding process, and the inner wall reaches a mirror finish

(3) Unitization of instrument components, convenient for maintenance and overhaul

(4) Alarm output (upper and lower limit extreme value alarm) high alarm point and low alarm point

(5) Standard signal isolation output (4-20mA) RS485 communication

(6) Provide SIL certification when necessary

Main technical performance of NK-100CY magnetic oxygen analyzer:

(1) Zero drift: ≤±1%FS

(2) Range drift: ≤±1%FS

(3) Measuring range: O2:0～21%

(4) Warm-up time: 30min

(5) Response time: ≤10s

(6) Output signal: 4～20mA (RL≤500Ω)

(7) Protection level: IP65

(8) Explosion-proof grade: ExdⅡCT6

NK-LAG100EX laser oxygen analyzer:

(1) Tunable laser spectroscopy technology, free from any background gas interference.

(2) The multi-reflection white cell is used to provide a measuring optical path length of up to 10m.

(3) Automatically eliminate environmental impact, with temperature and pressure compensation functions.

(4) The measurement speed can be as high as 100H Z, and the response speed is extremely fast.

(5) Stable performance, high sensitivity, and small long-term drift.

(6) Using optical measurement technology, it has a normal service life of more than 10 years.

Main technical parameters of NK-LAG100EX laser oxygen analyzer:

(1) Measuring range: 0~5/25%;

(2) Minimum resolution: 0.001%;

(3) Accuracy: 1%FS;

(4) Repeatability: 1%FS;

(5) Response time: τ 90 ≤10s;

(6) Flow rate: (0.3~0.5) L/min;

(7) Output signal: analog 4~20mA, digital RS485;

(8) Ambient temperature: -10~45℃;

(9) Environmental humidity: 0~95%;

(10) Protection level: IP66

(11) Explosion-proof grade: ExdⅡCT6

(12) Provide SIL certification when necessary