4results about How to "Control heating rate" patented technology

This application discloses a steam regulating valve assembly for a polycrystalline silicon differential pressure coupled distillation column. The steam regulating valve assembly is installed on the steam pipeline to regulate the amount of steam entering the reboiler. The steam regulating valve assembly includes: a main regulating valve unit, which is installed on the steam pipeline and has a first through-hole, and is used to regulate the flow rate of the main steam during the stable operation phase of the distillation column; and an auxiliary regulating valve unit, which is also installed on the steam pipeline and has a second through-hole, which is smaller than the first through-hole, and is used to perform micro-flow control of steam during the start-up phase of the distillation column.

The invention discloses a hollow three-dimensional crimped fiber with a high compression resilience rate and a preparation process, and relates to the field of fibers, and the hollow three-dimensional crimped fiber comprises the following raw materials by weight: 50-100 parts of bottle flakes; 10 to 50 parts of a soaking material; 5-15 parts of modified zinc oxide; 1 to 5 parts of styrene-methyl methacrylate resin; the modified zinc oxide is prepared from the following raw materials: zinc oxide, polyvinylpyrrolidone, water, chitosan and N, N-dimethylformamide. The compression resilience of the three-dimensional crimped fiber is improved.

The present invention relates to the field of catalyst technology, specifically to a method for preparing a mesoporous catalyst based on activated alumina. The present invention hydrolyzes ethyl orthosilicate and aluminum sec-butoxide together, mixes with a hard template and a soft template, introduces hydrogen, loads tungsten and nickel bimetallics after calcination, and then calcines again and acid-treats and ultrasonically obtains a mesoporous catalyst. By silicon-modifying alumina and controlling the calcination procedure, the obtained catalyst has a large specific surface area and pore volume; by controlling the addition of a hard template, a soft template and hydrogen, the obtained catalyst has a mesoporous structure and a stable pore configuration; tungsten and nickel are loaded on the activated alumina, the pH of the system, the ratio and total amount of metals are controlled, and the catalyst has high activity for the hydrodesulfurization reaction of sulfur-containing dibenzothiophene; by acid treatment and ultrasonication, the B acid amount, L acid amount and total acid amount of the catalyst are all improved; by protecting the hydrolysis site of alumina, the obtained catalyst has a good catalytic effect after 10 cycles of use.

The invention discloses composite brazing filler metal and a method for brazing connection of Ag and Ni-Cr alloy, and belongs to the technical field of brazing. The composite brazing filler metal is composed of, by mass, 40%-45% of silver, 25%-30% of copper, 20%-25% of zinc, 2%-3% of tin and 1%-5% of titanium. The method for brazing and connecting Ag and Ni-Cr alloy through the composite brazing filler metal comprises the steps that the composite brazing filler metal is evenly laid on the surface of a Ni-Cr alloy sheet, an Ag sheet is laid on the composite brazing filler metal, and a brazing structural part is obtained; and the brazed structural part is put into a vacuum brazing furnace to be heated, and the brazed structural part is taken out after temperature rising, heat preservation and cooling and cooled to the room temperature. By controlling the proportion of all metal elements in the composite brazing filler metal, the composite brazing filler metal with good wettability and joint filling capacity is obtained. According to the proportion of the composite brazing filler metal, the heating rate and the cooling rate during brazing are controlled, and the shear strength of a brazing structural part is improved.