75results about How to "Reduce ablation rate" patented technology

Disclosed is an elongating arc plasma jet ignition device. A swirler is fixed to the bottom of an inner cavity of a shell; a positive pole is located in the shell and fixedly connected with the swirler; the lower end of an insulation sleeve is installed in a central hole of the swirler, and an air chamber is formed in the gap between the outer peripheral surface of the middle of the insulation sleeve and the inner surface of the shell. A negative pole is embedded on a negative pole installation base, and the arc end of the negative pole extends out of the lower end of the insulation sleeve to be located in the positive pole. An arcing distance 2-8 mm long is kept between the arc end of the negative pole and a nozzle of the positive pole; an air inlet pipe is located at the upper end of the shell and communicated with the space of the air chamber formed between the insulation sleeve and the shell. The taper angle beta of the arc end of the negative pole is 40 degrees. The taper angle alpha of a contraction section of the positive pole is 60-90 degrees. Eight swirling holes with the spiral angle of 45 degrees are evenly distributed in an end surface of the swirler, and work media passing through the swirler generate swirling flow. The elongating arc plasma jet ignition device has the advantages of being high in flame spreading speed, high in penetrating power and rich in active air plasma.

A system for dental tissue treatment includes a system for directing a laser beam to an area of dental tissue to be treated, and a fluid-delivery system for directing and controlling a flow of a fluid. The fluid is directed to at least a portion of the area to be treated and the fluid flow is controlled to substantially prevent both a change in laser energy absorption by the dental tissue and attenuation of treatment efficiency due to fluid interference with the laser beam. The fluid present in at least a portion of the area to be treated may prevent or reduce the likelihood of melting of enamel in that area.

The invention provides a self-lubricating modular metal roller electric locomotive pantograph head with a damping structure. Pure carbon sliding plates are arranged on the two upper end surfaces of aU-shaped insulating base, and more than one group of metal rollers are arranged on the horizontal bottom plate of the base; the setting mode of each group of metal rollers is as follows: the lower parts of every two T-shaped insulating supports extend into grooves of a horizontal bottom plate respectively, and are arranged on fixing bolts which are screwed into the outer side of the horizontal bottom plate through holes in the horizontal bottom plate, spring damping mechanisms are symmetrically arranged on the left side and the right side of each insulating support, and the two metal rollers are arranged between the two supports through fixing shafts; and the structure of the metal rollers are is characterized in that the metal cylinders sleeve the metal shafts through insulating bearings,annular current-receiving electric brushes are fixed on the metal shafts, and the outer surfaces of the annular current-receiving electric brushes are in contact with the inner walls of the metal rollers. The self-lubricating modular metal roller electric locomotive pantograph head has the self-lubricating effect, is in flexible contact with an arch net and forms rolling friction fit, and has thecharacteristics of being capable of adapting to requirements of traction power of a train, being longer in service life and the like.

A system for dental tissue treatment includes a system for directing a laser beam to an area of dental tissue to be treated, and a fluid-delivery system for directing and controlling a flow of a fluid. The fluid is directed to at least a portion of the area to be treated and the fluid flow is controlled to substantially prevent both a change in laser energy absorption by the dental tissue and attenuation of treatment efficiency due to fluid interference with the laser beam. The fluid present in at least a portion of the area to be treated may prevent or reduce the likelihood of melting of enamel in that area.

The invention relates to oxide high-entropy ceramic with a defective fluorite structure and a preparation method of an anti-ablation coating of the oxide high-entropy ceramic. The preparation method comprises the following steps of: firstly, preparing high-entropy ceramic powder by adopting a high-temperature solid-phase reaction method; and then, by using a supersonic plasma spraying technology, preparing a high-entropy ceramic coating with corresponding components on the surface of a base material by using the high-entropy ceramic powder having been subjected to spray drying treatment. The high-entropy ceramic coating (HfZr(3RE))O2-delta (wherein RE is selected from Sm, Er, Ce, Y, Yb) provided by the invention has excellent phase stability and ablation resistance. In a supersonic plasma spraying process, the high-entropy ceramic is free of phase change and phase decomposition, and the prepared high-entropy ceramic coating still keeps the phase structure of the original high-entropy ceramic powder. The high-entropy ceramic coating is ablated and examined in oxyacetylene flames with heat flux density of 2.38 MW/m<2>, the highest temperature of the surface of the coating in the ablating process reaches 1900-2100 DEG C, the ablated coating does not have the phenomena of stripping, peeling and the like, an ablating rate is low, and excellent anti-ablating performance is shown.

The invention relates to a preparation method of Ageratina-adenophora-base high-specific-area activated carbon, belonging to the field of environmental protection. The method comprises the following steps: uniformly mixing KOH and an Ageratina adenophora carbonization material in a solid-phase state, filling into a ceramic crucible, and putting into a microwave high-temperature reactor; introducing nitrogen to evacuate air in the furnace, heating under microwaves to the last fewer minutes, quickly blowing CO2 into a guide tube communicated with the bottom of the ceramic crucible, and meanwhile, starting an ultrasonic generator; after finishing heating, washing the activated material with water, and recovering the residual KOH activator; and sequentially carrying out acid washing, water washing and drying to obtain the high-specific-area activated carbon. By using the Ageratina adenophora as the raw material, the method uses the CO2 bottom blowing mode to enhance the activation effect of the carbonization material, thereby lowering the production cost of the activated carbon, relieving the environmental pollution, changing harmful substances and waste into valuable substances and implementing comprehensive utilization of natural resources. The high-specific-area activated carbon can be effectively used in the fields of adsorptive collection of gasoline and other organic substances in automobile exhaust emissions and fuel system volatile substances, solvent recovery and the like.

The invention discloses an ablation-resistant organosilicon composite, and a preparation method and application thereof. The composite is a co-cured system of vinyl polymethylphenylsiloxane and silicic hydrovinyl polysilazane, and a silicic hydrogen addition or peroxide vulcanization system is adopted for vulcanization to obtain vulcanized rubber. The invention also discloses a preparation method and application of the composite. The ablation-resistant organosilicon composite has the characteristics of high high-temperature ceramic yield and favorable ablation resistance, and can be used for preparing heat insulating layers and fire-resisting cables of engines and the like.

Non-asbestos elastomeric insulating materials for solid propellant rocket motors are disclosed. The insulating materials are composed of EPDM rubber, polyaramide fiber, liquid EPDM rubber, magnesium hydroxide or aluminum hydroxide, silicon dioxide, chlorinated flame retardant compound and zinc hydroxystannate. The char forming organic fiber is used to substitute asbestos in traditional insulating materials that are believed to cause serious environmental problems. These fillers in the formulation, which when combined, have a synergistic effect that reduces the ablation rate significantly. Also, use of zinc hydroxystannate to substitute Sb₂O₃, may further reduce density of the insulator and smoke density and smoke toxicity of exhausted gas from the rocket motor.

The invention discloses a modified carbon fiber reinforced silicone rubber thermal-insulation material and a preparation method thereof, belonging to the technical field of thermal-insulation materials. The modified carbon fiber reinforced silicone rubber thermal-insulation material is prepared from the following raw materials in parts by weight: 40-60 parts of methyl vinyl silicone rubber, 40-60parts of methyl vinyl phenyl silicone rubber, 20-30 parts of white carbon black, 3-10 parts of graphene, 10-15 parts of modified carbon fibers and 0.5-1.5 parts of a vulcanizing agent. After carbon fibers are processed by virtue of concentrated nitric acid, the surface roughness of the carbon fibers is increased, and oxygen-containing functional groups are increased; after the carbon fibers are soaked in PEG6000 and alpha-aminopropyl triethoxysilane, the surfaces of the carbon fibers contain organic functional groups of N and Si. The tensile strength of the silicone rubber added with the modified carbon fibers reaches 2.96MPa, and the elongation at break reaches 57%; and compared with silicone rubber added with unmodified carbon fibers, the tensile strength and the elongation at break aregreatly increased, and the line ablation rate and the quality ablation rate are greatly decreased.

The invention relates to a method for vacuum reinforced desulfurization of high sulfur petroleum coke and belongs to the technical field of vacuum metallurgy. First petroleum coke is ground and screened to the granularity of 45-450 [mu]m, and the thickness is controlled to be 10-100 mm; under the vacuum degree of 10<-3>Pa to 100 Pa, the temperature rises to 1000-1600 DEG C at a heating rate of 10-50 DEG C and preserving heat for 10-90 min, the petroleum coke desulfurization efficiency reaches 70% or above, and elemental sulfur with a purity of 90% or above is collected in a condensation device at the top. According to the method, a low ash content of the petroleum coke is guaranteed without adding of an additive while a high desulfurization rate is achieved, it is also guaranteed that the petroleum coke has a high recovery rate after being desulfurized, the elemental sulfur can further be obtained in the process, and the problem that plenty of harmful SO2 gas unfavorable for collection is generated according to most of petroleum coke desulfurization methods is solved.

The invention relates to the field of comprehensive utilization of environment-friendly and hazardous solid waste resources, and particularly provides an industrial regeneration process of waste powdered activated carbon. By adopting a mode of firstly granulating and then carbonizing and activating in a rotary kiln, the influence of flying dust of powdered carbon is avoided, and the ablation rateis greatly reduced; the granulated activated carbon is wetted before feeding, so that the inhibition effect of introducing water vapor into the rotary kiln on flaming of a fuel machine is avoided, pore forming in the activation process is facilitated, and the activation effect is effectively achieved; the binder adopts an organic carbon source material with few impurities, no new impurity is added, the binder is used as a new carbon source, the activation raw material is increased, the operability is strong, and the method is suitable for industrialization.

The invention provides a multi-cavity plasma generator anode, which comprises a compression cavity, a stable combustion cavity, a conduction flow cavity and an accelerating cavity, which are connected in succession; the compression cavity is used to compress plasmas generated by a cathode; the stable combustion cavity can meet the requirement of plasma expansion; the conduction flow cavity provides a good electrically conductive path for conduction electrons; the accelerating cavity is a double-parabola structure formed by an upper-open parabola and a lower-open parabola; and the compression section is used to compress plasmas and improve plasma density, and the accelerating section is used to reduce the resistance of plasmas jetting form the leading end of the anode and increase plasma jetting velocity. The multi-cavity plasma generator anode provided by the invention is different from the traditional plasma generator anode, which adopts a first-compression-and-then-expansion type nozzle. In the invention, a unique multi-cavity anode construction is designed according to the expansion property of plasmas, and therefore the shortcoming of the traditional anode that the anode life is shortened due to too fast ablation rate resulting from the overlap of a conducting zone and an electric arc combustion zone is overcome.

The invention relates to a high-power long-life plasma torch based on permanent magnet constraint, comprising a cooling structure, a gas distributor, an integrated electrode, a permanent magnet lens and a plasma torch shell; the integrated electrode, the permanent magnet lens and the plasma torch shell are sequentially sleeved from inside to outside; the gas distributor is arranged at the head part of the plasma torch shell, and the external ionized medium gas generates spiral airflow after passing through the gas distributor; an arc is generated between the anode and the cathode of the integrated electrode, and the arc breaks down the spiral airflow to form an arc plasma jet. The plasma torch in the invention has the advantages of being high in temperature, high in enthalpy, centralized in energy height, high in energy conversion efficiency and long in service life, can generate a high-temperature environment, and is widely applied to fields of preparation and treatment of spaceflight, aviation, metallurgy, spray coating, high-temperature-resistant ceramic materials, nano-material preparation, material surface treatment, fuel conversion and combustion-supporting, harmful garbage treatment and the like.

The invention relates to a composite heat insulation structure resistant to long-time ablation overload. According to the composite heat insulation structure, a structure with a composite heat insulating layer is adopted. The composite heat insulating layer is structurally composed of two layers, namely an outer heat insulating layer and an inner heat insulating layer. The outer heat insulating layer is made of a GZ46-2 material, and the inner heat insulating layer is made of a GZ46-3 material. The thickness of the GZ46-3 material is 4 mm, the thickness of the GZ46-2 material is 6 mm, and in other words, the thickness ratio of the GZ46-2 material to the GZ46-3 material is 3: 2. After the outer heat insulating layer and the inner heat insulating layer are molded through die pressing, the inner heat insulating layer is bonded to the inner side surface of the outer heat insulating layer through adhesive. According to the composite heat insulation structure, the ablation rate is decreasedby about two magnitude orders compared with the maximum ablation rate of a common EPDM material heat insulating layer; and under the same working conditions, the thickness of the heat insulation structure can be effectively reduced, and the performance of a solid rocket engine is improved.