7results about How to "Control reaction rate" patented technology

The invention discloses a low-free-formaldehyde sodium glutamate-based gypsum retarder as well as a preparation method and application thereof, and belongs to the technical field of building material admixtures. The preparation method comprises the following steps: by taking sodium glutamate and formaldehyde as raw materials, carrying out an addition reaction at low temperature under a weakly alkaline condition regulated by calcium hydroxide to generate an intermediate; and then heating under an acidic condition to carry out dehydration polycondensation, and neutralizing by negative pressure and lime milk to prepare the sodium glutamate-formaldehyde condensation compound. The invention also discloses a retarder composition containing the condensate and a phosphate / zinc sulfate mixture. According to the invention, the content of free formaldehyde (1t; 300 mg / kg) is obviously reduced through improvement; the problem that the strength of gypsum is reduced due to a traditional retarder is solved by using the chelation of calcium ions and zinc sulfate.

The invention belongs to the technical field of isotope recovery and separation, and discloses a method for recovering high-abundance C13 carbon dioxide from C13 urea based on acidic constant-temperature hydrolysis. According to the method, the hydrolysis rate of the C13 urea is maintained by selecting proper dilute sulfuric acid concentration, sulfate radicals and urea are prevented from forming an adduct by controlling the dilute sulfuric acid concentration, the release efficiency of the 13CO2 is increased, the reaction rate is controlled, and side reaction is avoided. The invention further provides a set of reaction device for recycling 13CO2 through acidic constant-temperature hydrolysis of C13 urea under reduced pressure, the gas-liquid phase contact area and residence time are remarkably increased by arranging the rectifying column, visual water removal and low temperature are realized through the water removal column and the condenser pipe, the problems of external CO2 pollution, high impurity air content and relatively high water content are solved, and the method is suitable for industrial production. And high abundance recovery of the 13CO2 is ensured.

The utility model discloses a device for preventing a galvanized reaction tank pipeline from being blocked. The device comprises a tank body, a cover plate, a liquid outlet, a liquid inlet, a high-position overflow port, an emptying port, a ball valve and a hanging basket, the cover plate is movably connected to the top face of the tank body, the liquid outlet is connected to the middle of one side face of the tank body, the liquid inlet and the emptying port are connected to the bottoms of the opposite side faces of the two sides of the liquid outlet respectively, the high-position overflow port is connected to the top of the side face, where the emptying port is located, of the tank body, and the ball valve is connected to a pipeline connecting the liquid inlet and the emptying port. The hanging basket is movably connected to the inner side of the tank body; compared with the prior art, the hanging basket bearing the zinc plate is placed in the tank body for producing the zinc sulfate solution through the hoisting mechanism, the generated zinc sulfate solution is conveyed into the alloy liquid tank, zinc plating is carried out on the steel wire through electrolysis, and the electrolyzed sulfuric acid solution returns to the tank body from the liquid inlet; the solution in the tank body is not easy to splash out, the reaction condition of the zinc plate is convenient to observe, impurities and the like left by the reaction are deposited on the hanging basket, the cleaning is convenient, and the liquid inlet is not easy to block.

This invention provides an apparatus for preparing isocyanates, comprising: a heater; a reaction vessel disposed within the heater, the reaction vessel including at least a first opening, a second opening, and a third opening, each opening connecting the inside and outside of the reaction vessel; a gas input pipeline connected to the first opening; a condenser connected to the second opening; a receiving bottle connected to the end of the condenser away from the second opening; a distillation column connected to the third opening; a condenser with its inlet connected to the end of the distillation column away from the third opening and its outlet returning to the distillation column; a vacuum pump including at least a first inlet and a second inlet, the first inlet connected to the condenser and the second inlet connected to the condenser; and a gas output pipeline connected to the outlet of the vacuum pump. The preparation apparatus provided by this invention can solve the problems of low product yield, high purification difficulty, high reaction energy consumption, and high production cost.

The utility model discloses a fluorination furnace convenient to loading relates to fluorination reaction technical field, including furnace body and feed inlet, the feed inlet is located one end at the top of furnace body, is equipped with the conveying cylinder on the furnace body, the conveying cylinder top is equipped with first motor, first motor output is equipped with spiral conveying rod, spiral conveying rod rotatory connection is in the conveying cylinder inside, the conveying cylinder lower part one end is equipped with the feed frame, the conveying cylinder upper part one end is equipped with the discharge frame, and the discharge frame is located above the feed inlet. The utility model adds solid reactant in the conveying cylinder inside, then rotates spiral conveying rod, reaches the effect convenient for adding solid reactant to the inside of furnace body, can more accurately control the adding time and rate of reactant, to maximum limit improves the reaction efficiency and selectivity, not only can simplify the operation process, reduces the operation difficulty, can improve work efficiency.

The application provides a preparation method of nano silver powder with single particle dispersion. The method aims at solving the problems of easy agglomeration, high impurity and high cost of nano silver powder in the prior art. The method comprises the following steps: preparing an oxidizing agent solution containing a high molecular carboxylic acid or a salt thereof, a reducing agent solution, and a bottom solution containing a dispersant and a silver ion release regulator respectively; adjusting the pH of the bottom solution, and adding the oxidizing agent and the reducing agent solutions at the same flow rate to react; then, the target product is obtained through flocculant sedimentation purification, cleaning, drying and air grinding. The method controls the release of silver ions and the reaction rate through the synergistic effect of the high molecular carboxylic acid or the salt thereof, the silver ion release regulator and the like, and realizes the single particle dispersion of the nano silver powder without a large amount of dispersant, and is suitable for the fields of electronic information, biomedicine and the like.

The application discloses a method for regulating material reaction rate to improve finished product rate of aluminum-tantalum intermediate alloy, and relates to the technical field of intermediate alloy materials. The specific steps comprise the following steps: mixing large-granularity tantalum pentoxide, aluminum particles and potassium chlorate to obtain first-grade material; mixing medium-granularity tantalum pentoxide, aluminum particles and potassium chlorate to obtain second-grade material; mixing small-granularity tantalum pentoxide, aluminum particles and potassium chlorate to obtain third-grade material; sequentially adding the third-grade material, the second-grade material and the first-grade material into a reaction crucible, and insulating the materials by using porous aluminum foil, then performing aluminothermic reaction, and then performing gradient cooling to obtain aluminum-tantalum alloy without loose material. The reaction rate of the materials in the crucible gradually increases from top to bottom, the problems of poor slag-ingot separation and insufficient feeding caused by long formation of alloy liquid at the end of solidification and slow backflow are solved, the formation time of the alloy liquid in the later period is shortened, the backflow feeding is accelerated, the loose and stratification defects of the aluminum-tantalum alloy ingot are reduced, and the finished product rate is improved by more than 6%.