After the take-off pressure of the complete air separation plant is adjusted, the lock nut should be tightened to prevent the adjustment screw from loosening, so that the take-off pressure can be changed by itself. At the same time, cover the cover and seal it with lead, and do not change it arbitrarily. The lever type safety valve adjusts the take-off pressure by changing the position of the weight on the lever or changing the weight of the weight. After adjustment, it should be fixed and placed in an iron box for protection to prevent unauthorized movement. Make the foundation according to the manufacturer's drawings and local soil conditions. Clean the foundation holes and prepare about 10 horns (recommended 100mm×60mm×15mm, with a slope ratio of 1:12). Check the appearance of the wooden box, and then open the box and count the equipment and accessories;
Not as safe as immersion evaporators. Therefore, in order to improve the safety and reliability of the equipment, it is preferable to reduce some heat transfer effects. At present, the use of film evaporators is not recommended. For those that have been used, pay attention to ensure the liquid oxygen circulation volume of the liquid oxygen pump. For the degreasing of the pipeline and equipment of the complete set of air separation equipment, a degreasing agent should be selected first. There are four commonly used degreasing methods: perfusion method, circulation method, steam condensation method and scrubbing method. The degreasing method and amount of degreasing agent for the air separation tower, liquid oxygen container and pipeline are listed in Table 44. The quality of degreasing can be checked by the relative increase of the oil content in the degreasing agent after degreasing. When the full low pressure oxygen machine of the complete set of air separation plant encounters an emergency power failure, the first task is to quickly open the vent valve at the end of the air compressor and close the valve of the air entering the rectifying tower, so as to avoid the failure of the check valve at the outlet of the air compressor and cause the compressed air Reverse and make the air compressor reverse and burn out the bearing.
For an air separation plant that produces gaseous products, in order to cool the plant and accumulate liquid as quickly as possible during the start-up phase, its refrigeration capacity is much larger than that required for normal production. For example, for small and medium-pressure air separation plants, the cooling capacity can be increased by increasing the air pressure; for low-pressure air separation plants, the cooling capacity can be increased by increasing the expansion capacity. The complete set of air separation plant is the drying zone in the range of -60°C to -133°C. Using this principle, the cooling process of the equipment in the start-up operation is carried out in stages, that is, the staged cooling method. The whole cooling process is divided into 4 stages: the first stage is the water analysis and freezing stage. It is achievable to obtain a lower temperature than the environment in a complete set of air separation
plants by artificial methods. However, this requires a certain price, that is, consumes a certain amount of energy (work, electrical energy, etc.) to achieve. This process of artificially obtaining low temperature is called "refrigeration".
If the reflux liquid in the lower tower is too much, not only the liquid air purity will be too low, but also it may cause liquid flooding in the lower tower. Therefore, the large adjustment valve -1 should be opened at this time to improve the purity of liquid air and liquid oxygen, and while the liquid level continues to rise, the rectification conditions of the upper and lower towers will gradually become normal. When accumulating liquid oxygen, mastering the switching timing and mutual cooperation of several valves is an important method to speed up the rise of liquid oxygen level. Among the many processes that occur in nature, some can proceed spontaneously in one direction but not the other way round. Two gases with the same temperature and pressure are installed on both sides of a container. After the separator in the middle is pulled apart, the two gases will spontaneously and evenly mix, but work must be consumed to separate them.