5results about How to "Reduce total nitrogen" patented technology

This invention discloses a method for controlling sulfides in sulfur-containing gear steel, belonging to the field of metallurgical technology, including converter, LF refining, RH refining, and continuous casting processes. Converter process: molten steel tapping temperature 1630±20℃, carbon-oxygen product controlled below 0.0020; LF refining process: aluminum content in molten steel controlled at 0.035-0.045%, LF slag composition adjusted to R: 1.5-2.5, FeO+MnO: 1.0-2.0%; RH refining process: ferrotitanium added in one step to adjust the composition appropriately; Continuous casting process: argon-blown stopper rods and submerged entry nozzles are used for continuous casting, and 150-200 kg of low-basicity tundish covering agent is added to the tundish. The sulfur-containing gear steel produced by this invention can be continuously drawn for more than 10 heats, and the level of Class A inclusions can be stably controlled at A coarse ≤ 1.0 grade and A fine ≤ 1.5 grade, with a pass rate of over 99.9%.

The invention belongs to the technical field of casting, and particularly relates to a die casting protection casting device and a using method thereof. The die casting protection casting device is connected to a ladle nozzle in a sealed mode and comprises an upper sealing assembly, a lower sealing assembly and an adjusting device, and the upper sealing assembly and the lower sealing assembly are connected in a sealed and pressed mode. The adjusting device is connected to the steel ladle casting vehicle and connected with the upper sealing assembly. A ladle nozzle and a molten steel flowing area are wrapped, non-oxidation protection in the whole casting process is achieved, and the casting blank quality is improved.

The application discloses a kind of deep denitrification continuous flow aerobic granular sludge reactors and control method thereof, belong to wastewater treatment field.Reactor includes the anaerobic pool, aeration tank, anoxic tank, sludge separator and secondary sedimentation tank connected in sequence, and also includes intelligent control system.Control method includes: real-time monitoring state variable;According to the deviation of state variable and preset target value, the control input of last time and control barrier function, build performance function;Approximate long-term cost function using fractional kernel function;Calculate update error and update weight coefficient;Solve optimization problem to obtain control input;Execute control instruction.The application carries out intelligent optimization and closed-loop control to key operating parameters by safety reinforcement learning algorithm, maintains stable treatment effect when influent quality and quantity fluctuate, realizes efficient, stable, self-adapting deep denitrification operation, and has strong impact load capacity.

This utility model discloses an artificial enhanced aquatic ecosystem restoration system, mainly relating to the field of aquatic ecosystem restoration technology. The artificial enhanced aquatic ecosystem restoration system of this utility model is characterized by comprising a pretreatment system, an enhanced denitrification system, an artificial wetland system, a main control system, and a power supply system. The artificial enhanced aquatic ecosystem restoration system of this utility model has high removal efficiency for suspended solids, organic matter, and pollutants such as nitrogen and phosphorus in water bodies. Compared with existing technologies, this utility model has advantages such as enhanced denitrification, high integration, low carbon emissions and energy saving, good treatment effect, and low operating cost.

The application discloses a preparation method of 700MPa girder steel with excellent low-temperature toughness for high-cold regions, and belongs to the technical field of steel metallurgy, and comprises the following steps: S1, selecting a low-carbon mode for converter smelting, suppressing nitrogen increase through top and bottom combined blowing to strengthen the molten pool stirring, performing slag washing when tapping, and forming slag in advance; S2, LF refining, controlling nitrogen under 0.2MPa micro-positive pressure, creating low-melting-point refining slag and extreme desulfurization, removing large-size non-metallic inclusions, and performing modification treatment on residual MnS and Al2O3 by calcium treatment to remove small-size non-metallic inclusions; S3, full-process protection pouring of slab continuous casting, optimizing the electromagnetic stirring of the crystallizer, dynamic soft reduction, and cooling capacity of the secondary cooling zone under the premise of low superheat, and shortening TiN precipitation time; and S4, sequentially performing heating, rough rolling and finish rolling, and performing finish rolling in the austenite region, and rapidly cooling high-temperature austenite by low coiling, so that TiN is precipitated in a finer and more dispersed form.