Due to the increase of air velocity, pressure, backwater volume and spray volume, a large amount of water will be brought into the air separation tower. When the purifier was switched over, water was carried out due to the impact of air flow due to too fast speed. In order to prevent water carrying accident, careful management and operation of nitrogen water precooler should be strengthened.DEAR Biogas purification unit.At the beginning of the fourth stage of start-up, the liquid nitrogen control valve and upper tower blow off valve should be fully opened to conduct heat from the medium pressure channel and low pressure side of the main cooler and cool the main cooler thoroughly. When the liquid oxygen appears and the liquid level rises, the liquid nitrogen regulating valve remains open, and the blow off valve can be opened and closed intermittently.On the one hand, the corrugated fin in the middle of the partition plate supports the partition plate and increases the strength; on the other hand, it expands the heat transfer area, greatly increasing the heat transfer area per unit volume, so that the whole heat exchanger can be made compact. The fluid flows through channels in the fins. In order to realize the heat exchange between cold and hot fluids in the heat exchanger, the channels of cold and hot fluids should be arranged at intervals.
Platinum plating on activated alumina. The catalyst can directly hydrogenate oxygen to water at room temperature and raise the temperature to 130-400 ℃. The oxygen content is less than 0.5 × 10 ~ (- 6) and no additional heat source is needed. But it's expensive.After extracting argon fraction, it has a great influence on the working conditions from the liquid air feed port to the fraction extraction port of the main tower. Because the amount of rising steam decreases and the reflux ratio increases, more trays are needed to ensure the purity of liquid oxygen.If the temperature of the product channel and circulation channel in the middle of the switching heat exchanger is uniform, and the temperature deviation in the middle of other channels is very large, it is due to the bias flow caused by insufficient air volume. It is necessary to try to increase the air intake volume, which is generally used in rough adjustment. The product oxygen and nitrogen are backflow gases. Changing their flow distribution can also achieve the purpose of adjusting the temperature condition.
In operation, there are several incorrect uses: do not measure the temperature difference at the hot end. There is no thermometer connector in the pipeline; some have thermometer connector, but do not install thermometer; there is no thermometer connector, but the thermometer is directly tied to the pipeline to measure the temperature;The cooling water is preferably softened. It is easy to use magnetic water softener for softening treatment, and the effect is acceptable. Sedimentation tank should be set up to remove suspended solids. If the cooling water is recycled, it is conducive to the softening of water quality, but it covers a large area and has a large capital investment.DEAR Biogas purification unit.In the start-up stage, the task of accumulating liquid is completed by liquefier, not by condensing evaporator. Even if the expansion air is introduced into the condensing evaporator, because of the poor heat transfer effect, it is not competent to accumulate liquid. Not only that, but also the problem is that there is no expansion gas in and out of the circuit in the structure of the condensing evaporator.
