77results about How to "Improve the safe service life" patented technology

The invention discloses a method for grouting construction of a prestressed pipe. The method includes following steps: a pulper, a grout storage tank and a mudjack machine are connected through a pipeline; a discharge port of the mudjack machine is connected with a feed port of the prestressed pipe through the pipeline, and a discharge port of the prestressed pipe is connected with a vacuum pump through the pipeline; the pulper is started, mixing water and grouting material powder are added, water-binder ratio is controlled to be 0.27, stirring is performed for 3-5 minutes, fluidity is measured to be 10s-17s (second), and grouting material is poured in the grout storage tank; the vacuum pump is started so that pressure in the pipeline remains from minus 0.06 to minus 0.10 Mpa (mean pulmonary arterial pressure), and the mudjack machine is started to continue to grout; and when the other end of the prestressed pipe discharges cement paste identical to a stipulated fluidity, an outlet valve and the vacuum pump are shut, and then a grouting process is finished. The method has the advantages that prestressed concrete construction quality can be greatly improved, construction period is shorted, construction cost is saved, common quality problems like non-solid grouting and untight paste during pipeline grouting construction are solved, structure project quality of a prestressed bridge is guaranteed, and safety service life of a bridge is greatly enhanced.

The invention discloses a pesticidal compound taking chlorantraniliprole and monosultap as active ingredients. The weight ratio of the chlorantraniliprole and the monosultap is 1:1 to 100, and the sum of the weight of the chlorantraniliprole and the monosultap is 10 to 50 percent of the total weight of the compound. The pesticidal compound is added with a solvent or a hydrotropy agent, an emulsifier, a dispersant, a sharing emulsifying agent, an antifreeze, a foam killer, a thickening agent, a stabilizing agent, an adhesive, etc. which are all different, and can be processed into different agent types such as an emulsion in water (EW), a microemulsion (ME), a suspending agent (SC), a wettable powder (WP), or a water dispersible grain agent (WDG), etc. The pesticidal compound can effectively prevent agricultural insects, in particular is applicable to prevent rice insect pests, has obviously synergized action for the poison function of insects, shows the characteristics of wide range of desinsection, high efficiency, rapid functional speed, low toxicity for mammals and natural enemy insects, low dosage and agricultural use cost, no cross resistance among medicaments, etc., and overcomes and defers the generation of the drug fastness of pests.

The present invention relates to method of applying prestressed binding steel in reinforcing and repairing available concrete structure. The method includes the reinforcing method of adhering initial tension high strength steel sheet for reinforcing and adhering no-tension high strength steel sheet onto the concrete structure with reinforced displacement to reinforce. The reinforcing structure and the steel sheet realize the integral operation via high strength screws and binding surface to transfer shearing force. The reinforced concrete structure has greatly raised bearing capacity, rigidity and structural anti-cracking property within the normal operation stage. The method can prolong the safe service life of concrete structure and reduce investment for re-constructing building.

The invention provides a nitrogen injection gas well annular protection liquid capable of inhibiting oxygen corrosion and a preparation method thereof, and belongs to the technical field of corrosion protection of oil and gas wells. A nitrogen injection gas well annular protection liquid system is prepared from a corrosion inhibitor, a bactericide, a pH regulator, an oxygen scavenger, a density modifier and a scale inhibitor. The annular protection liquid comprises the following components in percentage by mass: 10%-12% of an imidazoline corrosion inhibitor, 0.5%-2.5% of an isothiazolinone fungicide, 3%-5% of an alkanes alcohol amine pH regulator, 6%-8% of a sulfite and oxime compound deoxidant, 10%-20% of an organic acid salt density regulator, 0.5%-1.5% of an organic phosphonic acid scale inhibitor, and the balance of water; and in necessary conditions, an appropriate amount of anti-swelling agent is added. The annular protection liquid provided by the invention can well control the annular oxygen corrosion problem of the nitrogen injection gas well and has the advantages of small damage to a reservoir, strong stability and environmental protection.

The invention discloses a preparation method of low-dielectric-constant insulating paper. The method comprises the following steps of: stirring and dispersing raw wood pulp by use of a defibering device; pouring the prepared SiO2 hollow microsphere suspension into the defibering device, mixing, and continuing to stirring, wherein the stirring temperature is normal temperature, the stirring time after the mixing is 2-10 minutes, and the stirring rate is 3,000r / min; after the stirring, manufacturing the insulating paper quantized to 120g / m<2> on a paper former; and compacting and forming, wherein the SiO2 hollow microsphere added to the obtained low-dielectric constant insulating paper accounts for 1-7%. In the modified insulating paper disclosed by the invention, silicon dioxide hollow microsphere is added, the insulating performance of a transformer composite insulating system is improved by reducing the relative dielectric constant of the insulating paper, and the safe service life is prolonged. Meanwhile, the steps of the preparation method are simple and easy to realize, and the cost is low.

An exterior vehicle headlight assembly protective cover, comprising of fabric or other material, extends across the front of the vehicle, covering the headlights of the vehicle. The protective cover blocks sunrays, dew, snow, ice, bird droppings, debris, and other elements when the vehicle is parked outside. The cover is dimensioned to cover the exterior of the vehicle headlight assemblies, by covering one headlight assembly then extending over across the front of the vehicle, over the grill area providing breathability to the vehicle grill area or over the hood area depending on the position of the headlights, then extending over and covering the second headlight assembly. The cover is held in place by a multitude of suction cups on the headlight assembly lens and surrounding area of the vehicle, including the front fenders.

The invention discloses a grout supplementing and pressing device for prestressed pipelines of a bridge and a construction method thereof. A vacuum grout supplementing and pressing device is arranged on a beam body in matched mode, a pre-buried pipeline in the vacuum grout supplementing and pressing device is arranged in the highest positions of the prestressed pipelines in the beam body. A vacuum pump, a grout supplementing and pressing funnel, a hose, a first three-way valve, a second three-way valve, a grout storage drum, an air inflation pipe and a high-pressure air pump are combined to complete overall grout supplementing and pressing construction. In the process of grout supplementing and pressing construction, treatment of pre-judging and detecting needs to be completed firstly, and then follow-up grout supplementing and pressing is conducted. By means of the optimized design, grout supplementing treatment can be effectively conducted on a cavity occurring in the beam body after grouting solidification, and grouting fullness is improved. Combining with the arrangement of the grout storage drum, the high-pressure air pump and the air inflation pipe, the treatment effect of a concrete air bubble film inside the beam body is improved. Meanwhile, the fullness and completeness of supplemented grout are further strengthened, the engineering quality of a prestressed structure of the bridge is guaranteed, and the safe service life of the bridge is greatly prolonged.

The invention provides low-cost oil-based annulus protection fluid applicable to a CO2 flooding well and a preparation method thereof and belongs to the technical field of corrosion protection of an oil and gas well. A low-cost oil-based annulus protection fluid system applicable to the CO2 flooding well is prepared by compounding engine oil, a corrosion inhibitor, a bactericide, an oxygen removing agent, a density regulator and a surfactant. The annulus protection fluid is prepared from the following components in percentage by mass: 1 percent to 3 percent of a morpholine derivative compoundcorrosion inhibitor, 0.8 percent to 1.6 percent of halogenated hydantoin bactericide, 3 percent to 5 percent of the oxygen removing agent, 5 percent to 30 percent of an organic acid salt density regulator, 3 percent to 5 percent of a non-ionic type polyoxyethylene type surfactant and the balance of the engine oil. The oil-based annulus protection fluid provided by the invention has a very good protection effect on a shaft tubular column of the CO2 flooding well and has the advantages of good high-temperature stability, good low-temperature freezing resistance and long-period stability; meanwhile, the refrigeration engine oil is used as a dispersant, so that the low-cost oil-based annulus protection fluid has the advantages of low cost and the like.

The invention discloses a heating furnace control and combustion optimization method. The problem that a heating furnace system is not easy to control is solved. A control strategy combining an advanced control algorithm and a conventional control algorithm is adopted, and continuous stable operation of the heating furnace system is ensured. O2 and CO switching control is used, and low-oxygen combustion is achieved. A national standard simplified formula serves as an optimized target. Real-time optimization of the oxygen content in flue gas is achieved through a self-optimization algorithm, and the aim of economical combustion is achieved.

A composite insecticide for paddy rice, vegetables, tea tree, cotton, flower, fruit tree, etc is prepared from Yinchongwei and monosultap in weight ratio of 1: (1-200).

The invention discloses a novel substitute material of seamless steel tubes for oil cylinders. The novel substitute material is prepared from the components in percentage by mass: 0.15-0.19% of C, 0.3-0.45% of Si, 1.35-1.6% of Mn, less than or equal to 0.025% of P, less than or equal to 0.015% of S, less than or equal to 0.25% of Cr, less than or equal to 0.25% of Ni, less than or equal to 0.1% ofMo, less than or equal to 0.1% of Ti, less than or equal to 0.1% of V, less than or equal to 0.2% of Cu, less than or equal to 0.025% of Al, less than or equal to 0.1% of Nb and the balance of Fe. According to the novel substitute material, by properly reducing the contents of C and Si, the carbon equivalent in the seamless steel tube material for the oil cylinders is maintained between 0.40% and0.45%, the weldability and heat sensitivity crack tendency of the material is reduced to a great extent, the safe service life of an oil cylinder product is prolonged, by reducing the content of C and properly increasing the content of Mn, a guarantee is provided for the impact toughness of the material after heat treatment, by optimizing the heat treatment process, the hardness after heat treatment is ensured to be 235-255 HB, the impact toughness at -20 DEG C exceeds 70 J, the turning performance of an oil cylinder pipe is improved, and meanwhile, the fatigue life in a severe environment isprolonged.

The invention discloses a felling saw. The felling saw comprises a casing provided with a side surface opening, a cover plate connected on one side surface of the casing, guide rails fixedly mounted on one inner side wall of the casing and arranged in the front-and-back direction of the casing, a mounting plate glidingly connected onto the guide rails, an electric push rod connected between the mounting plate and the back part of the inside of the casing as well as a motor fixedly connected on the mounting plate, wherein a rotating shaft of the motor extends to one side wall of the casing; the felling saw further comprises a guide plate connected to one outer side wall of the casing, chain wheels connected at the front end of the guide plate and on the rotating shaft of the motor as well as a saw chain connected between the two chain wheels. The tightness degree of the saw chain is adjusted automatically and conveniently through cooperative work of the electric push rod and a tension sensor, and the saw chain can be automatically adjusted to the state suitable for normal work without experience.

The invention relates to the technical field of battery fixing frames, and concretely relates to a detachable battery fixing frame for a new energy automobile based on sliding. The fixing frame comprises a clamping device, splicing devices are symmetrically arranged on one side of the clamping device, top sliding connection devices are arranged at the tops of the clamping device and the splicing devices, the clamping device comprises a clamping fixing frame, and cooling devices are symmetrically arranged on the two sides of the central axis of one side of the inner wall of the clamping fixing frame. Each cooling device comprises an annular motor shell, a motor is arranged in the motor shell, a rotating shaft is arranged at the circle center of one end of the motor, fan blades are arranged at one ends of the rotating shafts, each splicing device comprises a splicing fixing frame, and a battery is not convenient to detach from the fixing frame, and after an automobile is driven for a long time, a large amount of heat is generated between the batteries to increase the temperature in the fixing frame and soften protective shells on the surfaces of the batteries, so that electric shock and explosion danger are caused by wire contact, and the service life of the batteries is shortened.

The invention relates to a composite material buoyancy tank glued by a wood-plastic foaming board, a PIN core material and a foaming board, and belongs to the technical field of application of new buoyancy materials. A buoyancy tank which is low in mounting cost and can provide certain buoyancy needs to be mounted in agricultural and piscatorial water areas of which the water depth exceeds 3m or which are not suitable for piling construction, such as fishponds, reservoirs and lakes, so as to bear the weight of a photovoltaic power generators floating on the water surface. The composite material buoyancy tank is made according to the following steps of: dividing the foaming board according to a design drawing; bonding the divided foaming boards together with waterproof glue so as to form a buoyancy tank made of the foaming boards; filling the buoyancy tank made of the foaming boards with EPS buoyancy foams; gluing a waterproof two-sided adhesive tape with a PIN core material layer on the outer side of the buoyancy tank made of the foaming boards; and sequentially gluing the PIN core material layer, a wood-plastic foaming board and a glass-fiber wrapping layer by using waterproof glue from inside to outside so as to obtain the composite material buoyancy tank which is needed when photovoltaic power generation is performed on the water surface in agriculture and fishery.

The invention relates to the technical field of electronics, in particular to a soft-start / soft-turn-off electronic switch. The electronic switch comprises an electronic switch main circuit and a softstart / soft turn-off circuit. According to the electronic switch main circuit, an intelligent switch tube BTS555 is used as a core component; a modular design idea is adopted; universality and interchange of the electronic switch are realized; main electricity is input into the electronic switch main circuit. The electronic switch main circuit carries out current sampling and voltage sampling. A current signal and a voltage signal are respectively obtained through linear isolation; current sampling passes through an over-current protection circuit and is isolated by an optical coupler to obtain a protection signal. Wherein the soft start / soft turn-off circuit is connected with the electronic switch main circuit through the drive circuit, and a control signal passes through the optocouplerisolation and drive circuit in sequence and passes through the electronic switch main circuit to realize main power output, so that the current impact during starting of motor loads can be reduced, and the power supply quality is improved; and the reduction of the current impact is helpful for prolonging the safe service life of the power device.

The invention provides a battery collection device based on a flexible flat cable (FPC). The battery collection device comprises the flexible flat cable, wherein the flexible flat cable is provided with a plurality of acquisition arms, an acquisition system is arranged at the top end of each acquisition arm and comprises a voltage acquisition device and a plurality of acquisition wires arranged in the flexible flat cable, the voltage acquisition devices are arranged at the top ends of the acquisition arms, temperature acquisition devices are arranged on the voltage acquisition devices, a golden finger is also arranged at one end of the flexible flat cable, and the voltage acquisition devices, the temperature acquisition devices and the golden finger are connected through the acquisition wires. The battery collection device is integrated in wiring harness, high in acquisition precision and low in cost, is provided with multiple acquisition points, the safety of lithium batteries is effectively improved, and the service life of the lithium batteries is effectively prolonged.

The invention discloses a distributed bridge real-time monitoring device based on an LORA wireless communication. The device comprises three parts, namely a plurality of remote data acquisition nodes,a centralized monitoring terminal and an LORA wireless communication network, wherein networking is carried out through LORA wireless communication. By means of an analog switch gating, different operational amplifier gain feedback resistors are gated, different gain multiples are achieved, and different intensity signals are amplified under different working conditions; system working time synchronization and position positioning are realized through a GPS, and the synchronous work of the plurality of remote data acquisition nodes is ensured; a solar cell panel is used for generating electricity, a rechargeable battery is charged and accumulated through a battery management module, and a system power supply is provided for the remote data acquisition nodes; and an acoustic emission principle is applied to calculate and analyze acquired data in a centralized monitoring terminal, and positions and sizes of bridge cracks are determined. The device of the invention has the beneficial effects that accident potentials are found early, effective measures are taken, safe and healthy operations of bridges are ensured, and the safe service lives of the bridges are effectively prolonged.

The invention discloses a bridge crane conical motor, comprising a housing, a front end cover, and a rear end cover. The motor also comprises a motor shaft. The motor shaft is provided with a conical rotor. The outer ring of the conical rotor is provided with a stator matched with the conical rotor. The motor shaft is rotatably connected with the front end cover and the rear end cover respectively using bearings. The motor shaft is also provided with a part extending out of the rear end cover. The part of the motor shaft, extending out of the rear end cover, is provided with a bridge crane conical motor braking device. Since the part of the motor shaft of the bridge crane conical motor, extending out of the rear end cover, is provided with the bridge crane conical motor braking device, and a technical problem that an original bridge crane conical motor is prone to have friction between the rotor and the stator to burn the bridge crane conical motor is overcome. The bridge crane conical motor realizes to operate safely and stably, operation and maintenance cost of the bridge crane conical motor is reduced, and safe service life of the bridge crane conical motor is improved.

The invention discloses a reinforced aluminium alloy compressive cable. The reinforced aluminium alloy compressive cable comprises a tubular aluminium alloy conductor; a carbon fibre composite reinforced core is arranged in the centre of the tubular aluminium alloy conductor; a thin copper strip is arranged between the carbon fibre composite reinforced core and the tubular aluminium alloy conductor; an insulation layer is wrapped outside the tubular aluminium alloy conductor in an extruded manner; a single-wire layer, which is formed by a plurality of conductive single wires in a parallel winding manner, is wound outside the insulation layer; a buffer layer and an outer sheath are lapped outside the single-wire layer; and a metal compressive tube is also arranged between the buffer layer and the outer sheath. The reinforced aluminium alloy compressive cable disclosed by the invention is high in compressive strength and mechanical strength, good in moisture resistance, sealing performance and flexibility, low in cost and long in service life.

The invention relates to a building roof waterproof layer and belongs to the technical field of building technologies. The building roof waterproof layer comprises a metal substrate which is provided with a transparent flexible layer. A transparent protection layer is arranged on the transparent flexible layer which integrates the waterproof function and the function of providing cathode protection for the metal substrate. The transparent flexible layer can generate free electrons through light by means of the photoelectric effect. The building roof waterproof layer adopts the metal substrate with a cavity, so that an excellent heat preservation effect is achieved, and accordingly temperature control energy consumption in winter or summer can be reduced, and comfort is improved. The flexible layer adopted by the building roof waterproof layer integrates the waterproof function and the cathode protection function, the corrosion rate of the metal substrate can be greatly delayed, and the safety service life of a building roof can be prolonged remarkably. The building roof waterproof layer can be applied to roofs of commercial buildings such as markets and shopping centers, industrial buildings like industrial plants, and other buildings such as subways, airports and stations.

The invention discloses a power wire alarm device. The device comprises a mounting plate and a box body; the box body is fixedly arranged on the mounting plate; a current device is fixedly arranged inthe box body; a warning lamp and a buzzer are fixedly arranged at the top of the box body; a temperature sensor and a humidity sensor are fixedly mounted at the top of the cavity of the box; a plurality of air outlet pipes are equidistantly arranged in the box body from front to back; a small fan is fixedly mounted at the top of the box body through a bracket; the output end of the small fan is connected with a main air guide pipe in a sealed mode. The end, away from the small draught fan, of the main air guide pipe is connected with branch air guide pipes with the same number as the air outlet pipes. The device has the advantages that the moisture-proof, dust-proof and high-temperature-proof functions are realized, internal components can be effectively protected in the long-time use process, the safety service life of the device is greatly prolonged, and the practicability is realized.

The invention discloses an anti-steel-seepage furnace floor structure. The anti-steel-seepage furnace floor structure is composed of a furnace floor area, a furnace floor arc transition area and a molten pool transition area; the furnace floor area, the furnace floor arc transition area and the molten pool transition area are each provided with a lower permanent layer furnace lining and an upper working layer furnace lining, and the working layer furnace lining of the furnace floor arc transition area is closely built on the permanent layer furnace lining of the furnace floor arc transition area; the working layer furnace lining of the molten pool transition area is closely built on the permanent layer furnace lining of the molten pool transition area; and a triangle area is generated among the permanent layer furnace lining of the furnace floor arc transition area, the working layer furnace lining of the furnace floor arc transition area, the permanent layer furnace lining of the molten pool transition area and the working layer furnace lining of the molten pool transition area. The anti-steel-seepage furnace floor structure can give full play to the advantages of high density andhigh strength of shaping products.

The invention discloses a photosynthetic microorganism cultivation production system. The photosynthetic microorganism cultivation production system includes a ventilation circulation system, whereinthe ventilation circulation system comprises a gas supply unit, a ventilation pipeline unit, a rubber ball, a solenoid valve and a valve; the gas supply unit includes an air extraction device, an airsupply end purification device, precise air pressure detection controllers, a solenoid valve control system; the precise air pressure detection controllers are installed at both ends of a culture pipeline; the air extraction device adopts an active air pressure filtration purification device to accurately supply air, and used for keeping the air pressure difference between the inside and outside of the culture pipeline to be not more than + / -50Pa; and the air extraction device and the air supply end purification device are installed at both ends of the culture pipeline. According to the photosynthetic microorganism cultivation production system, the defects of the current two representative culture equipment systems are overcome, and culture, filtering, cleaning and sterilization are integrated, the safe service life of the equipment is greatly prolonged, the workload is significantly reduced, the working efficiency of culture is significantly improved, and the product quality is significantly improved.

The invention discloses a strain gauge attaching device and method for a deep-hole shaft pin sensor, and belongs to the field of shaft pin sensors. The problems that an existing strain gauge attaching device of a deep-hole shaft pin sensor cannot ensure that a strain gauge is accurately positioned and is poor in strain gauge attaching effect are solved. The strain gauge attaching device comprises two arc plates and a bar core. The arc plates are in a circular arc tile shape. Each arc plate comprises an inner arc face, an outer arc face and two transition faces between the inner arc face and the outer arc face, wherein the two transition faces are on the same plane. The cross section of the bar core is in a circular shape. The radius of the circular cross section is equal to the circular arc radius of the cross section of each inner arc face. The circular arc on the cross section of each outer arc face is concentric with the circular arc on the cross section of the corresponding inner arc face. According to the strain gauge attaching device and method, the position of the strain gauge in the deep-hole shaft pin senor can be accurately positioned, and therefore high-quality and accurately-measured products are obtained.

The invention discloses a saw chain of a felling saw. The saw chain comprises connecting chain links and cutting chain links connected through driving pieces, wherein the driving pieces are rotatably connected with the connecting chain links and the cutting chain links through rivets; the cutting chain links comprise left cutting chain links and right cutting chain links which are arranged in turns; the left cutting chain links comprise main connecting pieces, sub connecting pieces, connection parts connected between the main connecting pieces and the sub connecting pieces, cutting blades connected on the sides, away from the connection parts, on the main connecting pieces, and limiting heads which are integrally connected on the main connecting pieces and are positioned at the front of the cutting blades; notches are reserved between the limiting heads and the cutting blades; and the left cutting chain links are formed through stamping a complete metal piece. According to the saw chain, the structure is ingenious, the strength is high, the cutting speed is high, and the service life is relatively long.

The invention discloses an inflatable anti-explosion tire and a processing method thereof, and belongs to the field of tires. The inflatable anti-explosion tire comprises a tire body, an inner cavityis formed in the tire body, and spiral convex grains are arranged around the surface of the inner cavity. The spiral convex grains are wound around the center axis of the inner cavity in the annular direction of the surface of the inner cavity for a circle. Anti-pricking holes are formed between the tire surface of the tire body and the inner cavity in the direction of the center axis of the innercavity. According to the inflatable anti-explosion tire, the spiral convex grains are arranged on the surface of the inner cavity of the tire body, the surface structure of the inner cavity of the tire body is changed, the specific surface area is increased, framework stress is eliminated, the heat exchange effect is enhanced, the anti-explosion performance requirement is met, and the tire weightis not increased; by means of the processing method, the tire can be integrally formed, and the production cost is greatly reduced.

The invention discloses a welding gun for electrical construction. The welding gun comprises a welding gun main body and a handle. The welding gun main body comprises a gun head end and a gun breech end. The gun head end is provided with a gun nozzle, a heat isolating protective cover and a nylon plastic shell. The side wall of the welding gun main body is provided with a liquid crystal display screen. The gun breech end is provided with a rear cover. The gun nozzle is provided with a safety cap. The welding gun main body is internally provided with a heating main body. The side, close to thegun nozzle, of the heating main body is provided with a hot air pressurizing gun cap. The heating main body is internally provided with a wire ceramic skeleton. The wire ceramic skeleton is provided with a first heating wire and a second heating wire. According to the welding gun, after using of the welding gun is finished, a gun head can be protected by utilizing the safety cap; in the welding process, an air isolating layer can isolate air, so that a welded body is not oxidized; through the double-wire effect of the first heating wire and the second heating wire, heat accumulating can be conducted more quickly, and the temperature is increased quickly; a protector is loaded, thus real-time protection can be achieved; and when the temperature is abnormal, the protector can be fused automatically, and the service and safety life is longer.

The invention relates to a device and method for preventing a steam turbine shaft seal from leakage. Currently, no device which can solve the leakage problem of a steam turbine shaft seal from the root exists. The device for preventing the steam turbine shaft seal from leakage comprises a steam turbine which is provided with a shaft seal system, and the device is characterized by further comprising an air compressor, an air storage tank, an air drier and a shaft seal gap position nozzle block; the air storage tank is connected with the air compressor through a pipeline, the air drier is connected with the air storage tank through a pipeline, the shaft seal gap position nozzle block is connected with the air drier through a pipeline, and the shaft seal gap position nozzle block is distributed adjacent to the shaft seal system. A method for preventing the steam turbine shaft seal from leakage comprises the steps that the air compressor generates compressed air of high pressure, the compressed air is conveyed to the position of the shaft seal gap position nozzle block through the air storage tank and the air drier, the air is blasted to the shaft seal system, a high pressure air field is formed outside the shaft seal system, and the purpose of preventing the shaft seal system from leaking sealed steam outward is achieved. The device for preventing the steam turbine shaft seal from leakage is simple in structure, and the leakage problem of the steam turbine shaft seal is solved from the root.

The invention provides a motor power driver based on an IGBT transistor, which is characterized by comprising a shell (1), a CPU circuit board (2) and a driving output board (3), wherein the CPU circuit board (2) is connected with the driving output board (3) through a board level; the CPU circuit board (2) and the driving output board (3) are arranged in the shell (1); the CPU circuit board (2) can collect and analyze externally input control signals and output corresponding direction control signals and pulse signals with corresponding duty ratios, and therefore the speed of the motor is controlled; and the driving output board (3) can carry out overcurrent protection. The soft start / turn-off function is achieved, the soft start / turn-off function of the motor inductive load can be realized, suppression of the start current of the direct current motor is facilitated, the fluctuation of the direct current output voltage is reduced, and the safe service life of the power device and thedirect current motor is prolonged.