Opening words: In order to quickly implement the group's requirements for promoting the important work of "everyone offers a plan to avoid cost reduction", create an entrepreneurial atmosphere for officers, and set off a boom in cost reduction and efficiency reduction, Xindarong Media Center opened up a column of "Reducing this arena", excavating key measures and typical cases of independent improvement of production plants of various companies in the group, showing achievements, finding gaps, and promoting the same professional branch factories to catch up. Encourage all cadres and staff to strive for the day and night attitude, a comprehensive standard to find the difference, continue to improve efficiency and efficiency, establish a long-term competitive advantage of Xinda, and accelerate the high-quality development of enterprises!

Hebei Xinda steel oxygen QC problem team

The team is a professional improvement team led by Liu Fengsuo, director of the oxygen plant of Hebei Xinda Iron and Steel Group Co., LTD., consisting of ten engineers and production leaders. The research team regularly organizes meetings to discuss and solve technical and equipment problems encountered in production. Don't look at the team members are tough guys, but they attach great importance to details, and they will most "save money" to live, and in order to achieve the ultimate in cost reduction and efficiency, they must start from "small cuts". This is not, looking at the release of oxygen, they can not sit, factory director Liu Fengsuo said: "I spend energy to produce gas and then release, this is absolutely not, solve!"

Just-in-time production reduces oxygen fluctuations

When the pace of steelmaking and ironmaking production slows down, the amount of oxygen is reduced, which will cause the pressure in the oxygen main pipe to rise. In order to ensure safe production, it is necessary to open the vent valve to vent, resulting in oxygen waste. When the pace of steelmaking and ironmaking production is accelerated, the amount of oxygen is increased, which will cause the pressure in the oxygen main pipe to decrease, lower than the guaranteed supply pressure. Due to the contradiction between supply and demand, the pressure of hyperbaric oxygen fluctuates greatly, from 2.4MPa to 1.31MPa. In order to avoid waste, the research team decided to carry out research on the topic of reducing the peak-valley difference of oxygen external supply pressure and reducing oxygen fluctuation through JIT production, and set the research goal of reducing the peak-valley difference of oxygen external supply pressure from 1.0MPa to less than 0.4MPa.

[Reasons] The team summarized four main reasons through investigation: the sudden impact of steelmaking and ironmaking due to maintenance or adjustment of production load; Energy management communication is not timely, late production coordination is slow, resulting in the impact of gas supply mismatch; Oxygen permeation valve adjustment performance is poor; The operation of liquid oxygen pump affects. After the main causes are confirmed, the team will formulate a measure implementation table for the four main causes, and the responsibility is to the person, and the deadline is completed.

[Countermeasure] The team shall formulate how to carry out the conversion operation of gas and liquid products under oxygen pressure into the operation standard, and control the supply pressure and oxygen release. The Energy management Center and the production Department organized and established a wechat group to ensure effective and timely communication. The oxygen plant stops or starts the equipment to control the oxygen pressure and release according to the oxygen pressure level, which shortens the recovery time of the guaranteed supply pressure by nearly 40 minutes.

When steelmaking begins to use oxygen, the vent valve begins to close for hours, immediately turn to manual control and quickly turn off, wait for oxygen to be lowered to the set release pressure and then turn to automatic control, solve the waste of release, convert this part of oxygen into pressure oxygen and send out, reduce the fluctuation range of oxygen pressure. After starting the liquid oxygen pump, the frequency is controlled at 15HZ, the operating frequency can be increased in time when the oxygen pressure is reduced, and the frequency can be reduced to 15HZ when the oxygen pressure is increased, and the pump operation is no longer stopped, saving the cooling pump link and saving the operation time of nearly 10 minutes, so that the oxygen can be supplied in time.

"Don't look at these are some simple actions, but the combined force is huge!" Factory director Liu Fengsuo said. "Through this activity to solve the problem of oxygen supply pressure peak and valley pressure difference, reduce the oxygen release rate, improve economic benefits, while providing timely and efficient services for steel and iron gas."

Oxygen plant (Hebei Rongxin) research team

This is the oxygen factory (Hebei Rongxin) a team focused on improvement, the team members are all reducing the master, their eyes inward, from a small point of view, with a critical eye, do not let go of any details that can reduce costs and increase efficiency, and find ways to reduce costs, under the leadership of deputy factory director Wang Wanzhong, the team operation and maintenance members work together to constantly find cost reduction space, This time will focus on the air separation tower blowing time, to the time for indicators, to benefit!

Shorten the heating and blowing time of air separation tower

In the process of gas production, air compressor as an important production equipment, the maintenance cycle is generally two years, and the maintenance time is about half a month. After the end of the operation cycle, the air separation tower and each heat exchanger need to be heated and blown off, and the heated and blown off has no product output and consumes electric energy. If the start air compressor is used to heat the air separation tower, the blowing time is about 36 hours, and the actual operation time of the air compressor is extended, resulting in an increase in unit oxygen power consumption and an increase in cost. In this regard, the research team has only one idea, that is, "energy-saving purging", and then combined with the team's production and maintenance members to tackle this.

[Cause finding] The team members went deep into the production site, observed the actual purge situation, and decided to design a set of air separation system that could shorten the heating and blowing time of the air separation tower. The existing nitrogen gas was used as the heat source for heating and blowing, so that the air compressor, air precooling system and molecular sieve purification system were not started during the large heating process.

[Countermeasure] The inlet end of the air compressor is connected to the nitrogen output end of the air separation equipment. In order to facilitate monitoring whether the production line meets the working conditions, the input pipeline of the air separation system is equipped with a dew point detector. By detecting the dew point detector, the blowing effect in the production line can be known. Compared with the prior art, after the maintenance of the air compressor, only the switch valve and the check valve of the blowing pipe are opened, and the high-pressure nitrogen can enter the production line for blowing, which reduces the energy consumption of the air compressor for the heating and blowing of the production line after the maintenance, greatly shortens the operation time of the air compressor, and directly generates oxygen by hot driving to achieve the purpose of reducing cost and increasing efficiency.

[Results] After the improvement, the heating purge time was reduced from 36 hours before the research to 2 hours. The oxygen delivery pressure of steelmaking was 1.6MPa, the high-pressure oxygen delivery pressure of ironmaking was 0.9MPa, and the low-pressure oxygen delivery pressure was above 3kpa. Continuous and stable delivery, to meet the user's use. The implementation of the project successfully solved the problem that when the pressure supply cannot meet the demand, a large amount of liquid oxygen is consumed to evaporate to meet the production demand, and finally achieve the energy balance. It is estimated that the cost can be saved by 868,700 yuan each time.

The above is the independent improvement results of the gas unit, each of which solves the actual problems on the site, makes the production more scientific and efficient, and achieves cost reduction and efficiency increase. The process of independent improvement is more like a process of continuous transformation, breaking the cocoon into a butterfly, "liberating the mind", "liberating the hands and feet" and "liberating the vitality", releasing a steady stream of improvement power through the "liberation war", optimizing the production process and improving product quality. All staff and cadres should devote themselves to independent improvement activities with a high sense of ownership and a sense of mission to further enhance the core competitiveness of the enterprise.