250results about How to "Improve cavitation resistance" patented technology

The present invention relates to a pilot type hydraulic overflow valve. Its main valve body has front end cover, in said main valve body a main valve seat, a main valve buckle, a main valve core and a main valve spring are set, and said pilot valve is formed from its valve seat, valve core and pressure-regulating spring, said pilot valve is connected with said main valve. Said invention also provides the structure of main valve and pilot valve, and provides the application range of said valve.

The invention discloses a method for optimally designing impellers of bidirectional axial flow pumps. The method is characterized by comprising steps of designing hydraulic power on planar hydraulic power graphs of impellers in a central symmetry manner; completely modifying working faces of wing sections of the impellers into straight lines, enabling inlets and outlets of the backs of the wing sections of the impellers to be in circular arc transition, properly thickening the middles of the wing sections of the impellers and modifying the wing sections of the impellers into symmetrical structures; designing the impellers according to a plurality of main parameters including wrap angles phi of blades, diameters d<h> of hubs, diameters D of the impellers, setting angles beta<L> of lines, chord lengths I and radiuses R<1> of the lines. The method has the advantages that the performance of the impellers of the bidirectional axial flow pumps can be improved by means of optimizing the wing section and the planar graphs of the impellers on the basis of the traditional streamline method for designing impellers of axial flow pumps, and accordingly the purpose of improving the efficiency and the cavitation erosion resistance of the impellers of the bidirectional axial flow pumps can be achieved; high efficiency, a wide efficient range and the good cavitation erosion resistance of the bidirectional axial flow pumps can be guaranteed by the aid of the method, and the method is applicable to bidirectional axial flow pumps with the specific speeds ranging from 600 to 2000.

The invention discloses a double-stage variable-speed oppositely-rotating axial flow pump flow passage component for water spraying propelling. A primary-stage impeller is in an inducer mode. The rotating direction of the primary-stage impeller is opposite to the rotating direction of a secondary-stage impeller. The rotating speed of the primary-stage impeller and the rotating speed of the secondary-stage impeller are different so as to meet the cavitation performance requirement and the lift efficiency requirement respectively. The ratio of the rotating speed n1 of the primary-stage impeller to the rotating speed n2 of the secondary-stage impeller is between 1 and 2. The boss diameter ratio dh to D of the primary-stage impeller is between 0.25 and 0.6. According to the double-stage variable-speed oppositely-rotating axial flow pump flow passage component for water spraying propelling, a double-stage variable-speed oppositely-rotating axial flow pump is good in cavitation resistant performance, high in lift efficiency and compact in structure, expands the use range of a traditional axial flow pump, and is applicable to the water spraying propelling fields with the operating requirements of good cavitation resistant performance, high lift efficiency, compact structures and the like.

In the invention, epoxy, meidum plain emergy, diluent and curing agent are used as raw material, their weight percentage are (wt%): epoxy 12-16, medium plain emergy 73-82, diluent 1.5-2.5, curing agent 4.5-8.5. epoxy is optimum selected A-type E44 epoxy, medium plain emery can be river sand or quartz sand, diluent can be epoxy propane butyl ether, curing agent is optimum selected modified M-phthalic amine curing agent. Modifying method of said M-phthalic amine curing agent is that M-phthalic amine curing agent and monocycle oxo-compound do chemical combining reaction to generate liquid amine compound, then to be modified by acylate.

The present invention belongs to chemical paint technique area, specifically, it is amolybdenum disulfide fire-resistant anticorrosion antifriction paint. It selects fire-resistant bisphenol. A oxygen resin as gelatinizing agent, dicyandiamide as curing agent, molybdenum disulfide as lubricant, carbon black as antiseptic agent, and then add the mixed solvent. Finally the molybdenum disulfide fire resistant anticorrosion antifriction paint is formed. In the middle or high temperature environment, the coat has not only good abrasive resistance, bearing capacity and lubricity, but also excellent anticorrosion, grease-proof and erosion resistance. The effect: surface-prevention, antifriction, sealing, lubrication and extension the use of components. The metal sealing gasket painted with this paint can be used for a long time in the high temperature condition. It can reach the requirement of working in difficult condition, such as car ventilating pipe sealing components.

The invention relates to a double-doped grouting material for repairing a pavement and a preparation method of the double-doped grouting material. The double-doped grouting material is prepared from the following components in parts by weight: 50 to 70 parts of silicate cement, 20 to 30 parts of aluminate cement, 5 to 8 parts of silica fume, 10 to 15 parts of coal ash, 8 to 12 parts of barite powder, 1 to 3 parts of retarding admixture, 10 to 15 parts of waterborne epoxy resin, 3 to 8 parts of polyurethane, 0.5 to 0.8 part of antioxidant, 0.1 to 0.3 part of defoaming stabilizer, 1 to 4 parts of coupling agent, 0.3 to 0.5 part of surfactant, 3 to 8 parts of waste rubber powder, 0.05 to 0.2 part of cement reinforcing agent, and 0.1 to 0.3 part of water retaining agent. The double-doped grouting material prepared by the invention has high permeability, impact and wear resistance, high strength, high toughness, high temperature resistance and good durability, can solidify loose particles,has good binding property with original pavement concrete and is suitable for repairing various pavements.

The invention discloses a nanometer coating protective pipe prepared by nanometer squama coating and production technique of coating, wherein, the nanometer coating protective pipe consists of three parts of a pipe body, a basal layer and a function layer. The basal layer is the substrate of the nanometer coating and coated on the surface of the pipe body when contacts with a metal base body. The function layer is the facial layer of the nanometer coating and coated on the surface of the basal layer when the function layer contacts with corrosive medium. The nanometer coating the protective pipe disclosed in the invention changes the surface characteristic of the steel pipe products, and acquires a novel characteristic completely different from the original steel pipe products and enables the products to satisfy the need of people towards hi-tech development. The nanometer coating can provide oil pipe products with good performance in resisting corrosion, paraffin, scale and abrasion, so as to greatly prolong the maintenance period of the pipeline products in oil extracting wells, water injecting wells and conveying pipelines of oil fields.

The invention relates to the technical field of cavitation-erosion-resistant coatings, and discloses a method for preparing a cavitation-erosion-resistant coating through a thermal spraying and laserre-melting compound technology. The method comprises the following steps that (1) a metal ceramic composite coating is prepared on a matrix through thermal spraying; and (2), laser re-melting treatment is carried out on the metal ceramic composite coating obtained in the step (1), the surface of the metal ceramic coating is re-melted to form a new structure under high-density energy of lasers, thestructure property of the coating is enhanced after cooling, and the cavitation erosion resistance of the coating can be greatly improved. The method effectively eliminates the problem that ceramic powder deposits on the surface of the matrix through direct laser cladding, the obtained coating is low in porosity, the surface is compact and smooth, the cavitation erosion resistance is excellent, the coating can be widely applied to propellers, water turbine blades and other equipment prone to cavitation damage, the service life of the equipment can be prolonged, the frequency of maintaining the equipment due to cavitation damage is greatly reduced, and the using efficiency of the equipment is improved.

The invention relates to a mixed fiber concrete pipe, wherein mixed fiber concrete for forming the pipe comprises the following components according to the parts by weight: 322-540 parts of cement, 140-220 parts of water, 475-828 parts of sand, 864-1,306 parts of cobbles, 0.2-20 parts of polymer fibers and 20-140 parts of steel fibers. The mixed fiber concrete pipe has low raw material cost, light weight, high tensile strength, flexural strength, shearing strength and torsional strength, better durability and fatigue resistance, stronger capacities of shock resistance, abrasion resistance and cavitation resistance and better crack resistance, conforms to an energy saving and emission reduction policy and is a renewal product of the existing concrete pipes.

The invention discloses a cast steel part for an ultra-supercritical thermal power generating unit. The cast steel part is characterized by being prepared from the following chemical components in percentage by weight: 0.15 to 0.20% of C, not greater than 0.60% of Si, 0.4 to 0.8% of Mn, not greater than 0.02% of P, not greater than 0.015% of S, 2.2 to 2.5% of Cr, not greater than 0.5% of Ni, 0.5 to 0.8% of Mo, not greater than 0.5% of Cu, 0.3 to 0.4% of V, and the balance of Fe and inevitable micro impurities. The invention further discloses a process for producing the cast steel part. The cast steel part is high in wear resistance, corrosion resistance and heat resistance, high in toughness, and applicable to the ultra-supercritical thermal power generating unit.

The invention relates to a regulating angle valve, in particular to a black water coking-preventing impact-resistant shockproof regulating angle valve special for the coal chemical industry, and belongs to the field of fluid control valves. The black water coking-preventing impact-resistant shockproof regulating angle valve comprises a diffusion tube and a valve body, wherein the lower end of the valve body is connected with the diffusion tube through a bolt. An inlet flowing channel is arranged in the valve body, an outlet flowing channel is arranged in the diffusion tube and is communicated with the inlet flowing channel, and the inlet flowing channel is perpendicular to the outlet flowing channel. A valve carrier base is arranged in the outlet flowing channel and is clamped through the diffusion tube and the valve body, and a valve carrier is arranged in the valve carrier base. The black water coking-preventing impact-resistant shockproof regulating angle valve is simple in structure and novel in design, can effectively solve the technical problems that a traditional black water regulating angle valve is easy to coke, poor in impact resistant performance, undesirable in shockproof effect and the like in a use process, is widely applied in sites of customers, and effectively lowers production operation cost of the customers.

A servo valve of water pressure consists of permanent magnet torque motor, pre-amplification unit and sliding valve power unit. It is featured as arranging filter stopper at two ends of filtering screen end to form concentric circular seam between said stopper and valve body, opening valve body fixed damping hole at valve body between said stopper and valve bush, using water contained in gap between spool and valve bush to form fixed liquid resistance and spool static pressure support of pre -amplification unit.

The invention discloses a wear-resisting corrosion-resistant composite coating for a ship water-jet propeller impeller and a preparation method thereof, belonging to the technical field of corrosion-resistant wear-resisting coatings of a metal base body. The coating is obtained by a TiC in-situ reinforced NiTi intermetallic compound-based composite coating through solid-solution and aging treatment. The preparation method of the coating comprises the following steps: (1), preparing Ni-Ti-C composite powder by taking sucrose as a precursor of carbon and taking Ti powder and hydroxyl Ni powder as materials; (2), preparing a TiC in-situ reinforced NiTi intermetallic compound-based composite coating on the surface of a stainless steel impeller of a ship water-jet propeller by taking the Ni-Ti-C composite powder as the material through a plasma-beam cladding technology; and (3), carrying out solid-solution treatment and aging treatment on the coating obtained in the step (2) to obtain the coating. The coating disclosed by the invention can greatly improve cavitation erosion resistance, wearing resistance and corrosion resistance of the stainless steel impeller of the ship water-jet impeller.

The invention relates to a laser cladding anti-cavitation-erosion coating and a preparation method thereof, and belongs to the technical field of alloy coatings. The anti-cavitation-erosion coating isa shape memory alloy coating that is clad on the surface of a workpiece by a laser; and the shape memory alloy coating can absorb most of the energy and pulse stress generated by bubble-sweepdown based on cycling characteristics such as superelasticity and a shape memory effect of the shape memory alloy coating, and is subjected to superelastic deformation and martensite phase transformation, after external force is unloaded, the shape memory alloy coating is subjected to elastic recovery and martensite reverse phase transformation to be subjected to strain recovery, thus the most of the energy generated by the bubble-sweepdown can be buffered and dissipated, self-injury is avoided, and the purposes of prolonging the cavitation-erosion induction period and curbing initiation and propagation of cavitation-erosion cracks so as to improve anti-cavitation-erosion performance are realized. The technological process of laser cladding is simple, the coating can be prepared selectively at a local subtle position according to needs, and the cost is effectively reduced. The laser cladding titanium-nickel coating and the preparation method thereof can be used for preparation and repair of ship propellers, and have good economical efficiency and application prospects.

The invention discloses a cavitation prevention slurry pump. The cavitation prevention slurry pump comprises a pump body. The pump body is provided with a suck-in opening and a discharge opening. An impeller is arranged in the pump body and provided with main blades and induction blades. The induction blades extend into the suck-in opening. The main blades and the induction blades are connected. The cross section area of the suck-in opening is 3 to 10 times of the cross section area of the discharge opening. The invention aims at providing the slurry pump which can prevent cavitation and can convey high-concentration two-phase flow or high-vapor-content three-phase flow.

The invention relates to a multi-stage axial flow submerged pump with a long shaft and a method for conveying phosgene, which are mainly used for pressurizing and conveying the phosgene or chlorine gas. The submerged pump is provided with an inducer (1), a primary impeller (2), a secondary impeller (5), an auxiliary sliding bearing and shaft sleeve (6), a lower main sliding bearing and shaft sleeve (8), an upper main sliding bearing and shaft sleeve (10), a seal cavity (19) and a bearing bracket (28). The lower end of a packing box (13) is provided with an emergency seal rubber pneumatic bag (17); a double-end face mechanical seal (22) is sleeved on a pump shaft (30); a radial balancing hole (37) is arranged on the impeller; and the auxiliary sliding bearing and shaft sleeve (6) is made from silicon carbide. When both of the mechanical seal and the packing seal become invalid, high pressure nitrogen gas ensures that the emergency seal rubber pneumatic bag (17) is inflated to clasp the shaft so as to quickly block leakage of the conveyed phosgene.

The invention discloses a multistage deep sea mixture pump with an axial force transmission structure. The pump comprises a pump case. Two ends of the pump case are fixedly provided with an inlet pumpcover and an outlet pump cover. The other end of the outlet pump cover is fixedly connected with an outlet connecting pipe. The outlet pump cover is coaxially provided with an outlet bearing pedestal. The other end of the inlet pump cover is fixedly connected with an inlet connecting pipe, a bearing box, and a motor. The inlet pump cover is coaxially provided with an inlet bearing pedestal. The bearing box is internally provided with a bearing box shaft. One end of the bearing box, far away from a motor, extends into the inlet connecting pipe. The pump case is internally provided with a pumpshaft. One end of the pump shaft extends into the inlet connecting pipe and is connected with the bearing box by a shaft, and the other end of the pump shaft is in the outlet bearing pedestal. A plurality of stages of static pressure expanders are uniformly sleeved on the pump shaft along an axial direction in sequence. Ends of the pressure expanders, close to the inlet pump cover, are provided with closed impellers which are fixedly coupled with the pump shaft in a cooperated manner. A thrust collar is arranged between a first stage impeller and the inlet bearing pedestal. The pump is high inoperation efficiency under a working condition of high gas content, and the pump is easy to process and install.

The invention relates to a broken line inlet type hole plug energy dissipater used for a pressure spillway tunnel. The broken line inlet type hole plug energy dissipater comprises a hole plug base and an overflowing hole arranged in the hole plug base, the overflowing hole is formed by connecting two contract truncated cone-shaped holes which are provided with front ends larger than rear ends and are in different tapers, and the outlet of the front contract truncated cone-shaped hole is the inlet of the rear contract truncated cone-shaped hole. Total length L0 of a hole plug meets the following relation: L0=0.6 D0-2.5D0, the diameter D1 of the inlet of the front contract truncated cone-shaped hole meets the following relation: D1=0.6 D0-1.0D0, the ratio D1/D2 of the diameter D1 of the inlet of the front contract truncated cone-shaped hole to the diameter D2 of the outlet of the front contract truncated cone-shaped hole is 1.05-1.3, the length L1 of the front contract truncated cone-shaped hole meets the following relation: L1 =0.1 L0-0.4L0, and the ratio D2/D3 of the diameter D2 of the inlet of the rear contract truncated cone-shaped hole to the diameter D3 of the outlet of the rear contract truncated cone-shaped hole is 1.05-1.4, wherein D0 is the diameter of a spillway tunnel in the relations.

The invention relates to a preparation method of a water-based magneto rheological hydraulic transmission medium, comprising: proportioning 55-70% of deionized soft water, 29-45% of magnetic particle and 1-10% of additive; successively adding; and mixing and stirring to obtain the water-based magneto rheological hydraulic transmission medium. The medium has good stability and inoxidizability and can greatly improve the abrasion resistance and the rust protection of a hydraulic system working medium.

The invention discloses a designing method of a cylindrical blade with the controllable inlet setting angle. A designing and shape drawing process of a novel cylindrical blade is given. The inlet edge of the novel blade and the blade inlet attack angle at the intersection of a front cover plate and a rear cover plate can both be given. The impact hydraulic loss at the positions of the blade inlet can be reduced through the controllable inlet setting angle, the major reason for the large hydraulic loss of a traditional cylindrical blade is eliminated, and the purpose of increasing the blade energy index is achieved. The anti-cavitation capability of the blade can be improved through the blade structure, and the application range of the cylindrical blade is enlarged. After the blade is used in an impeller with the specific speed reaching 120, a pump can still have high hydraulic efficiency.