5results about How to "Implement looping" patented technology

The utility model discloses a traditional chinese medicine rhizoma polygonati processing and impurity removing device, including turning and washing cage mechanism and the water tank of setting at turning and washing cage mechanism below position, the turning and washing cage mechanism is including the interval setting of both sides polyhedral support, a plurality of metal blocking net board structure can be dismantled and installed between polyhedral support, turning and washing cage mechanism still includes the spray -washing structure of setting in turning and washing cage mechanism, and the spray -washing structure includes long shower nozzle, and the bottom of long shower nozzle is equipped with a plurality of downward spray -washing setting's shower nozzle, the water outlet end position of water tank is installed with water pump, and the water outlet end of water pump is connected long shower nozzle. The above structure realizes the automatic cleaning, and can turn over the tuber big rhizoma polygonati in the cleaning process, improves the cleaning efficiency and improves the cleaning effect.

The present invention provides a 5-methyl-1, 3, 4-oxadiazolone synthesis method, which comprises: 1, adding ethyl acetate to a reactor, dropwise adding 80 wt% hydrazine hydrate to the reactor at a temperature of 20-80 DEG C, and carrying out a reflux reaction after the dropwise adding is completed; carrying out reduced pressure distillation on the reaction liquid after the reaction is completed to remove byproducts and ethyl acetate; step 2, at room temperature and normal pressure, adding aqueous alkali and a catalyst into a system subjected to reduced pressure distillation in the step 1, cooling the system to 10 DEG C under uniform stirring, adding triphosgene in batches for 1-3 hours, heating to 20-30 DEG C after the charging is finished, and carrying out heat preservation reaction for 6-7 hours; acethydrazide residues are detected in the reaction process, the reaction can be stopped when the acethydrazide residues are smaller than or equal to 1 wt%, insoluble substances are gradually separated out in the system in the heat preservation process, and 5-methyl-1, 3, 4-oxadiazolone is obtained. In the synthesis process, the triphosgene is used for replacing phosgene, so that the product yield is ensured, the requirements on reaction equipment are reduced, the comprehensive cost is reduced, the wastewater is recycled and reused, and the method is a synthesis method suitable for industrialization.

The application provides a method and a process system for continuously producing citronellal from citral. The method comprises the following steps: introducing hydrogen into citral to produce citronellal under the catalysis of a catalyst; wherein the hydrogen introduced in the hydrogenation reaction contains 100-600 ppm of activating gas; and the activating gas is selected from NO or NO2. The method and device for continuously producing citronellal from citral provided by the application overcome the shortcoming that noble metal catalysts in aldehyde systems are easily poisoned by CO generated by aldehyde decomposition, realize online activation of the catalyst, and realize circulation and reuse of the catalyst in the reactor.

The invention discloses a synthetic method of 4, 4 '-dihydroxybiphenyl. The method comprises the following steps: mixing 4, 4 '-dinitrobiphenyl, a metal catalyst and an organic solvent, introducing hydrogen, and carrying out hydrogenation reduction reaction to obtain 4, 4'-diaminobiphenyl; the preparation method comprises the following steps: mixing 4, 4 '-diaminobiphenyl and a silicon dioxide grafted modified multi-branched carboxylic acid polymer, carrying out a heating reaction, and removing a solvent from a reaction solution to obtain 4, 4'-dihydroxybiphenyl. 4, 4 '-dinitrobiphenyl is used as a substrate of the reaction, and an intermediate 4, 4'-diaminobiphenyl is obtained after hydrogenation reduction; the target product 4, 4 '-dihydroxybiphenyl is synthesized by taking the silicon dioxide grafted and modified multi-branched carboxylic acid polymer as a hydrolysis reagent, so that the efficiency and selectivity of the reaction for preparing the 4, 4'-dihydroxybiphenyl are effectively improved, the reaction condition is mild, the operation process is simple and convenient, and the method has wide industrial application potential.

The application discloses a method for continuously preparing 4,4'-dichloromethyl biphenyl, which comprises the following steps: pumping a paraformaldehyde, hydrochloric acid and a catalyst solution into a first-stage tubular reactor to perform a formaldehyde depolymerization reaction, and then pumping the depolymerization reaction solution into a second-stage tubular reactor to perform a chloromethylation reaction in the presence of biphenyl and a chlorinating reagent, and finally discharging the reaction solution from the tubular reactor to perform cooling crystallization and filtration to obtain a 4,4'-dichloromethyl biphenyl crude product, and recycling and reusing the catalyst in the system. The method has the advantages of high reaction efficiency, simple system, low cost, high yield and easy industrial production.