52results about How to "The preparation process is easy to operate" patented technology

Lactic acid obtained by a method for producing lactic acid, the method comprising: (A) a step of continuous fermentation wherein a fermentation culture medium of a microorganism having an ability of lactic acid fermentation is filtered through a porous membrane having an average pore size of not less than 0.01 µm and less than 1 µm with a transmembrane pressure difference within the range of 0.1 to 20 kPa, and the permeate is collected, while retaining the non-permeated liquid in or returning the non-permeated liquid to the culture, and adding a fermentation feedstock to the culture; (B) a step of filtering the permeate obtained in Step (A) through a nanofiltration membrane; and (C) a step of distilling the permeate obtained in Step (B) under a pressure of not less than 1 Pa and not more than atmospheric pressure, at 25°C to 200°C to recover lactic acid; comprises only small amounts of impurities, and a polylactic acid obtained using the lactic acid as a raw material has excellent thermal stability, mechanical strength and hue.

The invention provides a screw-in type pipeline connector. The screw-in type pipeline connector comprises a pressure-bearing joint used for connecting two pipelines and two screw-in type squeezing rings symmetrically arranged on the two sides of the inner surface of the pressure-bearing joint. The pressure-bearing joint is of a tubular symmetrical structure with a middle transition line as the baseline. Circumferential sealing rings and annularly-distributed axial anchoring teeth are arranged on the pressure-bearing joint and are respectively located on the two sides of a middle transition section. Rectangular threads are symmetrically arranged at the two ends of the inner oblique surface of a squeezing groove of the pressure-bearing joint. Rectangular threads matched with the rectangularthreads on the inner oblique surface of the pressure-bearing joint are arranged on the outer surfaces of the screw-in type squeezing rings. The screw-in type pipeline connector is simple in structureand capable of realizing connection of submarine pipelines and broken pipelines rapidly and reliably.

The invention discloses an additive solution for a cooling system as well as a preparation method and a use method of the additive solution. The additive solution comprises the following components inpercentage by mass: 30-65% of an alcohol solvent, 1-5% of a composite additive and 30-69% of deionized water, the preparation method comprises the following steps: respectively adding the alcohol solvent and the deionized water in percentage by mass, uniformly stirring, adding the composite additive, and uniformly mixing; the use method comprises the following steps: detecting the pH value of thecooling liquid, judging whether the cooling liquid is invalid or not, detecting whether the cooling water tank is damaged and leaks or not, opening the water tank cover in the cooling state of the engine, adding the additive liquid to a specified liquid level scale, finally starting the engine to heat the vehicle, and continuing to supplement the additive liquid if the liquid level is reduced. The cooling system additive solution provided by the invention is good in corrosion inhibition effect and storage stability, not only can prolong the service life of the original vehicle cooling liquidand save social resources and maintenance cost, but also can effectively enhance the anti-corrosion, anti-freezing, anti-boiling and anti-scaling properties and the like of the original vehicle cooling liquid.

The invention discloses an environment-friendly rustproof powder coating. The environment-friendly rustproof powder coating is prepared from, by weight, 55-105 parts of GMA type acrylic resin, 45-110 parts of epoxy resin, 18-68 parts of absolute ethyl alcohol, 28-58 parts of linseed oil, 200-400 parts of methylbenzene solutions, 5-10 parts of titanium dioxide, 3-10 parts of degassing agents, 2-8 parts of flexibilizer and 1-15 parts of flatting agents. The environment-friendly rustproof powder coating in the technical scheme is high in purity and large in adhesive force, both the powder coating and the coating production process are free of three-waste pollution, and therefore the environment-friendly effect is good; the powder coating can be recovered and coated for the second time and is resistant to acid, alkali and abrasion and waterproof, and a rustproof film is smooth, long in service life and good in rustproof capacity.