36results about How to "Control vacuum" patented technology

This invention relates to a heat conduction tube and its manufacturing method including the following steps: providing a tube with a first and a second open-end and fixing said tube, vacuuming said tube from the first open-end till the tube reaches to a pre-designed vacuum degree, sealing the first open-end to get a first sealed segment, injecting liquid from the second open-end and sealing it to get a second sealed segment. The heat conduction tube prepared by said method includes a sealed tube with a capillary structure and suitable working medium, in which, both ends of said tube are in staved sealed segments.

A vacuum refreshing device for a refrigerator belongs to the field of vacuum refreshing. The vacuum refreshing device is arranged in a refrigerating box of the refrigerator, and comprises at least one vacuum box, a vacuum generation device for vacuumizing the vacuum box, and a vacuum control device for controlling pumping and preserving of vacuum. Through the arrangement of the vacuum generation device and the vacuum control device in the refrigerator, the degree of vacuum in the vacuum box is controlled well, so that food is isolated from air to be in negative-pressure and hypoxia environment, which prolongs the food refreshing time.

The invention provides an RH refining method for controlling wettability of inclusions in low-carbon aluminum killed steel. Through controlling the components, the adding time, the adding amount and the adding mode of an inclusion modifier, and in cooperation of the vacuum degree control and process adjustment in the RH refining process, so that the surface of the aluminum oxide inclusions is completely covered or partially covered with 2Al-2 O-3.CaO and 6Al-2 O-3.CaO, and the modified form of the inclusions is surface modification or local surface modification. On the basis of controlling thevacuum degree of RH refining, the yield of the modifier can be improved, and the problem of molten steel pollution caused by the modifier is reduced. On the basis that the refining process and the period are not influenced, the surface wettability of the aluminum oxide inclusions in the molten steel is improved. The problem of water opening nodulation in the continuous casting process can be relieved, and the problem of liquid level abnormal fluctuation caused by the water opening nodulation is avoided; and the problem of aggregation of the aluminum oxide inclusions in the solidification process of the molten steel is relieved, so that the cleanliness of the molten steel is improved, and the product quality of the low-carbon aluminum killed steel is improved.

The invention relates to a method for the batch production of granules made of polycondensation polymers by pre-condensating an oligomer at 5 to 400 mbar and by means of subsequent polycondensation in a rotating disc reactor and subsequent granulation. In the area of the discharge connection piece, the dragging surface density ranges between 1 and 8m<2> per m<3> in the reactor chamber and is steadily increased at an increasing distance from the discharge area. There is a viscosity gradient within the reactor and between the area that is the remotest from the discharge connection piece and the zone of the discharge connection piece. Thermal reduction of the polymer melt draining off from the reactor is compensated during granulation. The rotating disc reactor comprising a horizontal and longitudinal axis has approximately the form of a simple or double truncated cone. The reactor has rotatable, vertical product dragging surfaces and stationary strippers therebetween.

The invention relates to the technical field of refrigerators, in particular to a device and a method for controlling the vacuum degree of a vacuum refreshing refrigerator, which comprises a vacuum refreshing box, a vacuum pump, a pressure switch and a master control board, wherein the vacuum pump is communicated with the vacuum refreshing box, a pressure detection end of the pressure switch is communicated with the vacuum refreshing box, a pressure signal output end of the pressure switch is connected with the master control board, and a control signal output end of the master control board,which controls the action of the vacuum pump according to a pressure signal of the pressure switch, is connected with a signal input end of the vacuum pump electrically. In the control method, the pressure switch is used for detecting the air pressure of the vacuum refreshing box and outputting the pressure signal according to the air pressure to control the action of the vacuum pump. In the invention, the pressure switch is added to control the vacuum degree inside the refreshing box to be kept in a certain range all the time, and the control range is adjustable; moreover, the pressure switch has the advantages of simple structure and low cost and is safe and reliable.

The invention relates to a preparation method of an optical frequency band metamaterial based on gold-branch-shaped units and particularly relates to a preparation method of a metamaterial. The preparation method of the metamaterial comprises the following steps: firstly preparing the gold-branch-shaped units in an aqueous solution by using dodecyltrimethylammonium bromide as a template by virtue of a nano self-assembly method, then assembling the prepared gold-branch-shaped units into a single-layer array on a glass substrate, coating the surface of the single-layer array with a PVA (Poly Vinyl Alcoho) film and overlapping the single-layer array and a sheet of ITO (Indium Tin Oxide) conductive glass to form the metamaterial of a composite structure. The metamaterial shows relatively strong transmission passband peak in a visible light frequency band and has obvious plate focusing effect on light with corresponding wavelengths.

The invention discloses an air blowing type vacuum sucking disc and a vacuum adsorption device with the air blowing type vacuum sucking disc. The air blowing type vacuum sucking disc comprises an inner barrel, an adsorption disc which is arranged at the bottom of the inner barrel and covers an opening in the bottom of the inner barrel, and an outer barrel which is arranged outside the inner barrel in a sleeving manner, wherein negative pressure holes are formed in the side wall of the inner barrel; the inner barrel is provided with unidirectional sealing elements used for unidirectionally sealing the negative pressure holes; the unidirectional sealing elements prevent airflow from flowing from the outer side of the inner barrel into the inner barrel through the negative pressure holes; the adsorption disc is provided with suction holes; exhaust holes are formed in the side wall of the outer barrel; the exhaust holes are positioned below the negative pressure holes; and the bottom of the outer barrel and the bottom of the inner barrel are hermetically connected. According to the novel-structure vacuum sucking disc provided by the invention, ordinary vacuum sucking discs are made vacuum through extracting air with a vacuum machine; and in the air blowing type vacuum sucking disc, an air compressor is adopted to generate compressed air, the compressed air flows directionally at a high speed, and a vacuum state is achieved, namely, the vacuum state is achieved through adopting an air blowing method.

The invention provides a cationic dyeable PET and a composite elastic fiber prepared therefrom. The preparation method of cationic dyeable PET includes: mixing titanium dioxide, terephthalic acid and ethylene glycol and beating to obtain a slurry; performing esterification and precondensation on the slurry respectively, and adding dihydroxyisophthalic acid to the precondensation product Propyl ester-5-sodium sulfonate is initially melt-blended to obtain the primary product of cationic dyeable PET; the primary product of cationic dyeable PET is subjected to solid-phase viscosity increasing treatment to obtain cationic dyeable PET. Cationic dyeable PET / PTT composite elastic fiber is prepared by melt composite spinning of cationic dyeable PET and PTT. The technical solution provided by the invention effectively solves the problem that the current PET fiber is difficult to unify with full extinction and deep dyeing. The prepared product has good performance, high added value, easy process realization, and is conducive to large-scale production. It is suitable for elastic fabrics such as clothing and home textiles Wide application prospects.