The first volume of the deceitful year of the lust of Xiangjiang Iron and Steel Co., Ltd. coal-fired compressed air freeze-drying system design Li Hanming Xiangtan Iron and Steel Company dynamic discharge self-contamination introduction With the increase of coal injection volume of blast furnace, the pulverized coal transportation is required to be stable and uniform, smooth flow, pulsation phenomenon less.
Therefore, in recent years, people have put forward higher requirements for the quality of compressed air of coal powder conveying medium, requiring compressed air to be free from pollution.
There are three types of pollutants in compressed air, namely oil dust and water.
The oil is derived from the compressor lubricating oil, and some of them are often decomposed to form oxides, such as organic acids. The water-soluble substances are highly corrosive, and other liquid oxides form oily and sticky residues.
Liquid water may contain ionic soluble gases. For example, when water is in contact with steel, iron oxide hydrate is usually formed. This reddish brown powdery substance is insoluble in water and may also form dirt and cause blockage of certain parts.
Two commonly used compressed air drying methods are commonly used in the compressed air drying method in the industry. There are two adsorption methods and a freezing method.
The adsorption method uses a special desiccant to absorb the moisture in the compressed air by its physical properties, and uses the method of transformation or temperature change to explain the regeneration to achieve the purpose of recycling.
The adsorption method is suitable for the manufacture of more than one compressed air with a dew point. The gas loss is relatively large, generally 15 for cold areas.
The freezing method uses the freezing principle to achieve air drying by reducing the temperature of the compressed air.
The freeze dryer is a popular drying equipment developed at the end of the decade and at the beginning of the generation. It does not consume any desiccant, nor does it need to regenerate gas. The dew point is stable and the price is low.
This method is applicable to the manufacture of dew point temperatures.
Above compressed air.
The picture shows the working principle of the water-cooled freezer.
Wet air first entered the date one contact Li Hanming senior engineer Hunan Xiangtan City Xiangtan Iron and Steel Co., Ltd. design institute pre-cooler, heat exchange pre-cooling with the frozen outlet air can be pre-cooled to a 25 and then enter the evaporator and cold medium quality freon Heat exchange cooling, cooling to a pressure dew point equivalent to the atmospheric pressure dew point, a cooled air enters the oil water separator, removes mechanical water and oil droplets, and then enters the pre-cooler to pre-cool the newly incoming humid air, and finally from the The air inlet enters the pipe network.
The function of the pre-cooler is to pre-cool the inlet humid air, save energy to heat the outlet cold air, prevent secondary condensation and condensation outside the outlet pipe and downstream pipeline, and improve the compressed air. The amount of water.
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Compressed air outlet wet air inlet cooling water outlet diagram water-cooled freezer working principle Xianggang compressed air freeze-drying system design Xianggang Steel Injection Workshop existing two series of coal powder preparation system and three series of blast furnace coal injection system, another set The pulverized coal conveying station uses only the coal for the blast furnace. The current total gas consumption is 3 and the fire 2 piston air compressor.
The original system does not have a compressed air drying device, and only a part of the mechanical water can be removed by the gas storage tank. Therefore, the compressed air has a large water content and oil content.
In production, especially in the rainy season in spring and summer, equipment failures such as blockage of coal plugs under blocked pipes often occur. In severe cases, the coal mouth is often repaired, and the phenomenon of dripping of coal powder is often found.
In the past, the production level of the blast furnace in Xiangtan Iron and Steel Co., Ltd. was low, and the understanding of coal injection coke was insufficient, and there was insufficient investment in the technical transformation of the coal injection system.
With the continuous improvement of the technical indicators of the blast furnace, especially the iron production has been greatly improved, the coke supply of the coking plant of the company has become increasingly tight, and the blast furnace coal injection has become an important process of blast furnace production.
In order to ensure that the blast furnace can stably and uniformly spray coal, the company has modified the compressed air drying system of the coal injection workshop in the year to solve the difficulties caused by the excessive oil content of compressed air.
Xianggang Iron and Steel Co., Ltd. uses compressed air drying method for drying compressed air. The process flow is shown in the figure.
The original parameters of the design are air treatment volume storage tank outlet temperature 50-60 air oil content-water content, environmental parameters during the test, atmospheric temperature, atmospheric pressure, atmospheric humidity, air pressure station, oil-cooled water, frozen water, and an arsenic cold-drying One is away from the dryer machine, the first one of the factory, the person L map Xianggang refrigerating dryer process design points are as follows: 1) compressed air treatment amount A factory recommended selection table or freeze dryer dual-use one parallel arrangement.
The design considers that the intake air volume of the equalization stage freeze dryer is difficult due to the difference in the pipeline layout system. Therefore, a freeze dryer is selected to simplify the system.
As for the dual-use and one-time preparation, not only the investment is increased, but also the pipeline layout is long, the valves are numerous, the system is complicated, and the land is occupied.
From the perspective of system operation, there is not much need.
Because the manufacturer promises that the freeze dryer can run for many years, similar to the household refrigerator system, except for the oil-water separator, there is no other wearing parts, and the time for replacing the filter is extremely short.
Therefore, there is no need to increase investment.
The freeze dryer is divided into normal type and high temperature type according to the inlet air temperature.
The air inlet temperature is a common type and requires a high temperature type.
Although Xianggang's coal injection air compressor has a rear cooler, the temperature of the compressed air after the cooler is still high. Generally, the B plant recommends the use of a high-temperature freeze dryer, so that the cooler before the freeze dryer can be eliminated.
However, the design considers that Xianggang uses a piston air compressor and has been used for many years. The compressed air contains a large amount of oil. If the compressed air cannot be effectively degreased before entering the freeze dryer, the multi-oil gas enters the freeze dryer. When the refrigerant evaporator is used, the low-temperature refrigerant copper tube is easily adhered by the oil, thereby lowering the cooling efficiency.
Xianggang's coal-fired air compressor piston cylinder uses the lubricating oil. The kinematic viscosity of the mechanical lubricating oil is inversely proportional to the temperature. Therefore, if the compressed air enters the oil-water separator before the freeze dryer, it can effectively remove the oil. It is necessary to reduce the temperature of the compressed air before the oil-water separator.
After the viscosity is increased, the diameter of the oil mist droplets is correspondingly increased, and the oil filtering efficiency of the separator is greatly improved.
The design is provided with a compressed air cooler in front of the oil-water separator in front of the freeze dryer, and the freeze dryer is a water-cooled common type.
The rational selection and use of the water separator is also an important part of whether the freeze-drying system can adapt to the gas used for coal injection.
The higher the grade of the separator, the higher the efficiency of oil-water separation, but the greater the gas resistance.
The principle of separator setting in the system should be that the level before the freeze dryer is low and the level after it is high.
The filter particle size of the oil-water separator in the freeze dryer is generally the oil-water separator after the freeze-drying of the oil-water separator before the freeze-drying machine is selected.
The reason is that the resistance of the fine oil-water separator is large, which will affect the pressure of the gas for coal injection. The coal injection process does not require excessively pure compressed air. The amount of dewatering of the fine separator accounts for a small proportion of the system's dewatering amount.
The freeze-drying system is set as close as possible to the air compressor station rather than the user's coal injection station because the dew point of the air changes as the pressure changes.
The compressed air pressure drop from Xianggang's coal injection air compressor station to the coal injection station is about.
Does not contain freeze-drying system resistance.
The temperature of the outlet gas of the freeze dryer is low. During the pipeline transportation from the freeze-drying system to the coal injection station, there is also a heating process, especially in the southern region, where the temperature of the compressed air is increased, which can increase the water capacity, that is, reduce the gas. Humidity, which is another benefit of the freeze-drying system near the air compressor station.
Inspired by this, the drying method can be used for drying the compressed air, and the reverse side can also be used. In fact, the heating method has been practiced.
Operational Effects The authors have examined the freeze-drying system of compressed air in three ironworks in China.
The Taiwanese freeze dryer used in the two blast furnaces was put into operation in less than two months.
The freeze dryer of the factory also basically fails. The compressed air part passes through the freeze dryer and partially passes the bypass pipe. If the freeze dryer is completely gone, the compressed air resistance is too large to meet the pressure requirement of the coal injection. The freeze dryer actually It is in a semi-squat state.
Only the freeze dryer of Taiwan's Taiwanese has been running for half a year, the effect is better, but after the compressed air from the system comes out of the freeze dryer, before the coal injection station is installed, a compressed air heating device is added according to the scene, and the heater is not installed. Before, the freeze-drying system is not easy to use, and the three plants of the coal-fired plugging pipe are discharged from the air-storage tank of the air compressor station before entering the freeze-drying machine, and no cooler is provided for cooling, and the freeze-drying system is close to the coal injection station. Settings.
The operation of the CO2 compressed air freeze-drying system of Xiangtan Iron and Steel Co., Ltd. is very good. The effect of the on-site reflection is very good. The pipe blocking phenomenon has not occurred, and the coal injection is even and stable.
The original amount of coal injected in the blast furnace is now reached at the rate of more than eight in the case of no oxygen enrichment.
The chilled-drying system provides high-quality compressed air, which is an important prerequisite. The equipment failure of the gas-using equipment is also greatly reduced, especially in the past, solenoid valves that often have clogging problems, and almost no clogging.
Practice has proved that the design of the freeze-drying system is successful, the process is reasonable, the equipment selection is appropriate, the system is simple, the investment is less, the compressed air dewatering effect is good, the production requirements are met, and the intended purpose is achieved.
Hu Hui technical information single-layer self-cleaning cantilever screen vibrating screen on the blast furnace development and application by identifying a single-layer double-sided self-cleaning cantilever screen vibrating screen in the blast furnace application of this technology, greatly reducing the entry into the blast furnace The amount of powder in the blast furnace was developed and applied. The powder control day in the sinter was passed by the Shandong Metallurgical Industry Corporation, and the identification of the host who entered the mine was also reduced.
The quantity of qualified products makes the qualified mines in the returning mine less than the average screening efficiency of Laiwu Iron and Steel Co., Ltd. Laiwu Iron and Steel Co., Ltd. and the long-term insurance company ironmaking plant. Jinan Zhongran Industrial Development Co., Ltd. is stable and reduced. The workload of the screen is cleaned, so that the single-layer double-sided self-cleaning cantilever screen mesh assisted by the division improves the gas permeability of the column, improves the blast furnace antegrade, and improves the development and application of the production sieve on the blast furnace. The quantity reduces the consumption of the finished sinter and reduces the production of pig iron into good economic and social benefits.
The blast furnace can create more than 0 million economic benefits in one year. This technology has obtained national patents.
Its development and response.
The development of single-layer double-sided self-cleaning cantilever screen vibrating screen not only fundamentally solves the long-term and application of raw material screening in ironmaking industry, but also for the first time in China.
Due to its reasonable structure, it has been a key technical problem, and it has also been designed for other industries. Therefore, it has a successful experience in improving the screening quality with light weight and wear resistance.
Low life and long screening are characterized by high efficiency and stability.
Laigang Wuhan Iron and Steel Design and Research Institute Cheng Jianguo
Professional Sheet Metal Fabrication,Professional CNC Fabrication Service,Custom Sheet Metal Fabrication,Precision Sheet Metal Fabrication
Ningbo Jiongke Technology Co., Ltd , https://www.precisioncncmachiningparts.com