46results about How to "Improve pollution resistance" patented technology

The invention discloses a pilot stage digital electro-hydraulic servo valve with variable area gradient. A high-speed switch valve is respectively installed in the control chambers on both sides of the electro-hydraulic servo valve to form a pilot stage; the digital servo controller utilizes negative feedback to Two high-speed on-off valves are controlled; through the control of the high-speed on-off valve, the pressure difference between the two control chambers of the spool is formed to control the movement of the spool; The edge of the orifice is designed to have a continuously variable area gradient, so that the area gradient of the orifice increases with the increase of the displacement of the spool. It can be seen that the pilot stage of the present invention adopts two high-speed on-off valves of the same type, combined with a digital controller to realize valve core displacement control, which not only has good dynamic characteristics, but also improves the anti-pollution ability of the servo valve, thereby reducing the failure rate; The design of the edge of the orifice of the sleeve can improve the zero resolution and flow control accuracy, and at the same time can achieve a larger rated flow.

The invention discloses a powder decoration coating and preparation and construction methods thereof, and belongs to the technical field of coatings. The powder decoration coating comprises raw materials in parts by weight as follows: 40-70 parts of shell powder of 1,000-2,000 meshes, 10-30 parts of a powder functional material, 2-10 parts of dispersible gelatin powder and / or a silicate cross-linked substance, 1-5 parts of sepiolite short-fibers and 5-30 parts of colorful composite rock slices. The powder decoration coating is prepared from the shell powder calcinated at the temperature of 300 DEG C, the powder functional filler, the colorful composite rock slices, the powder cross-linked substance and functional additives through blending, the shell powder calcinated at the temperature of 300 DEG C is taken as a main material, and the powder decoration coating is good in breathability, anti-condensation, scrubbing-resistant, pollution-resistant, anti-bacterial, mould-proof and non-inflammable and has a green and environment-friendly inorganic system and a colorful decoration effect.

The invention provides a model-based method for electro-hydraulic proportional loading and belongs to the technical field of hydraulic loading technology and automation. The method comprises the following steps: pre-establishing conversion relations between the control current and the pressure of a hydraulic proportion valve at different flow rates, namely models; and selecting a corresponding model according to the actual flow rate to complete the pressure control of the proportion valve. As the different models are adopted under different conditions, the control accuracy is improved greatly.As the established models possibly have certain errors, a feedback compensation process is adopted to eliminate the errors in the models. As a result, the pressure control accuracy of the electro-hydraulic proportional valve is improved, the response time is reduced, and the requirements on pressure, force or torque loading are met.

The invention discloses a grounding method for a composite insulating pole tower of a power transmission line and a pole tower thereof. The pole tower main body adopts a composite tube, a conductor cross arm adopts a composite insulator, a ground wire cross arm adopts a metal conductor, a grounding down-lead adopts a metal wire or a tube or a bar, the grounding down-lead is suspended from the middle of the tube and is led down to be grounded, the ground wire cross arm and the conductor cross arm are provided with metal electrodes, and the proper part of the pole tower is perforated for arranging the grounding down-lead to lead out the electrodes; and the air gap distance between the ground wire side electrode and the conductor side electrode and the air gap distance between the leading-out electrode of the grounding down-lead and the conductor can be determined according to the lightning protection requirement. The grounding mode of the composite pole tower effectively utilizes the insulating property of a composite pole, can improve the pollution flashover and ice flashover resistance, wind deflection prevention and lightning protection level of the line, can also compress the size of a tower head, and has the advantages of reducing the manufacturing cost and the transportation, assembly and maintenance expenses of the pole tower main body and reducing corridor width of the line at the same time.