259results about How to "Shorten maintenance period" patented technology

Problems with accuracy reading position detection signal peaks and minute phase differences in the detection current make motor drive control easily susceptible to differences in motor characteristics. The rotor position is determined based on whether or not a neutral point difference voltage, which is the difference voltage between the neutral point voltage and the pseudo-neutral-point voltage when the motor phases are selectively energized, exceeds a specific threshold value. The phase energized to start the motor is determined based on this determination and the motor is energized accordingly to start. Instead of switching directly from the search step at the initial rotor position to the back-EMF voltage mode, a search and start mode that creates initial rotor speed sufficient to start the motor is executed before entering the back-EMF voltage mode.

The invention relates to a shape memory alloy energy consumption combined column with a resetting function and a mounting method thereof and belongs to the technical field of structural projects. Theshape memory alloy energy consumption combined column comprises a foundation, assembled square steel pipe columns, I-shaped columns, H-shaped steel beams, anti-buckling supports and connecting short beams, T-shaped splicing plates are fixed to the joint area parts of the assembled square steel pipe columns, and grooves are formed in the upper portions and the lower protons of the T-shaped splicingplates correspondingly. The T-shaped splicing plates and the assembled square steel pipe columns are connected by self-locking bolts, the joint area parts of the I-shaped columns are connected by resetting joints, and the middle of each layer of each I-shaped column is connected by three splicing plates through bolts. Shape memory alloy long bolts are arranged between the upper flanges and the lowerflanges of the I-shaped columns, one ends of L-shaped connecting plates are fixedly connected with the connecting short beams, the other ends of the L-shaped connecting plates are fixedly connectedwith the H-shaped steel beams, and ribbed plates are welded to the corresponding positions of the columns. The anti-buckling supports between the assembled square steel pipe columns and the I-shapedcolumns are connected in a combined mode. According to the shape memory alloy energy consumption combined column with the resetting function and the mounting method thereof, the effects that completeassembling is conducted on a construction site, energy dissipating can be achieved in an earthquake, and the after-earthquake restoring capacity is improved are achieved.

A socket box, equipped with means allowing it to be fixed to a circular opening made in the wall of a block of a building's wall upon an expansion effect of the socket box's structure, whose structure portions are displaced by using expansion screws, which, when turned, cause the socket box to be locked in opening made in block.

Provided are a sewing design manufacturing management apparatus and method, which can provide information associated with sewing processes necessary for manufacturing an end product, on the basis of sewing design information. In order for a user to easily input information and data necessary for a sewing process, a design shape for each process is provided by analyzing the sewing design information of an end product generated or provided from the outside. The design shape for each process makes it easier to input sewing information and sewing data on a corresponding process. Working hours and cost may be calculated on the basis of at least one of the input sewing information and sewing data. The sewing information and sewing data may be transmitted to a corresponding sewing manufacturing device over a network, thereby setting work parameters for performing a necessary process.

The purpose of the present invention is to shorten the period of time for which a cryptographic key for one-time pad (OTP) cryptography will be insufficient, when using OTP cryptography to encrypt and send data encoding audio or video. Terminal device A (102) uses the number of bits remaining in an OTP cryptographic key (401) to select one of two encoding methods to use for encoding outgoing data: encoding method A, or encoding method B (which has a lower bit rate than encoding method A). Terminal device A (102) uses the selected encoding method to encode the outgoing data and generate encoded data. Using the OTP cryptographic key, terminal device A (102) then generates encrypted transmission data (405) by using OTP cryptography to encrypt the generated encoded data, and sends the generated encrypted transmission data (405) to terminal device B (103).

The invention discloses a CFB boiler inlaid type hood air distributing device and an improving method thereof, and belongs to the technical field of heat-engine plant circulating fluidized bed boiler air distribution plate transformation. The CFB boiler inlaid type hood air distributing device comprises a tube nest, air distribution plate castable and the like. The tube nest is located at the upper portion of an air chamber. Hearth water wall tubes are evenly arranged below the tube nest. The air distribution plate castable is laid on the tube nest with reserved gaps. An air pipe B is inlaid in an air pipe A, penetrates the tube nest and extends into the air chamber. The air pipe A and the air pipe B are fixed through welding points. A strengthening casing pipe is fixed to the intersection position of the air pipe A and the tube nest. Small air holes of the air pipe B are formed in the upper portion, above the air pipe A, of the air pipe B. An I-shaped hood is buckled at the upper portion of the air pipe A, and I-shaped hood air outlet holes are formed in the I-shaped hood. According to the CFB boiler inlaid type hood air distributing device and the improving method thereof, welding and fixing points are broken by dismounting the hood, part of air pipes are cut, new air pipes are inserted, welding and fixing are conducted, and therefore the running resistance of an air distribution plate can be adjusted; and the problems that the air distributing uniformity is poor, temperature distribution is uneven, slag leaks in the air chamber, and the power consumption of a primary draught fan is large are solved.

The invention relates to the technical field of vanadium-titanium ore metallurgy and discloses a residual iron discharging method for a vanadium-titanium ore smelting furnace. According to the erosion particularities of the bottom and a hearth of a titanium slag blast furnace used for vanadium-titanium magnetic iron ore smelting, it is found that the bottom and the hearth of the titanium slag blast furnace used for vanadium-titanium ore smelting are eroded in a 'circular truncated cone plus pan bottom' shape; and through organization of previous furnace clearing materials and data statistics, by means of a comparative analysis method, the position of a residual iron opening of the blast furnace is marked, the erosion conditions of the bottom and the hearth of the furnace are determined, and the amount of residual iron is calculated. It is proved through practice that by means of the residual iron discharging scheme, the maintenance time limit can be remarkably shortened; labor intensity of furnacemen is remarkably lowered; furthermore, furnace clearing cost is lowered; and the residual iron discharging method is more precise, more efficient, more scientific and more reasonable.

The invention provides oil-based cleaning agent for petrochemical equipment. The oil-based cleaning agent is prepared from the following raw materials in percentage by mass: 9-12% of an emulsifiable penetrant, 1-2% of a penetrant, 1-2% of a non-ionic surfactant, 1-2% of a complexing agent, 1-1.5% of an antirust agent and the balance of an assistant. The cleaning agent is efficient, free of pollution and simple in operation process, is compatible with existing petrochemical equipment, and the cleaning and operating cost is lower. A system cleaned by the cleaning agent can reach a ferrous sulfide cleaning effect, and ferrous sulfide cleaning does not need to be carried out again. The cleaning agent does not contain a strong oxidant or a heavy metal ion of affecting sump oil recycling. The cleaning process is free of wastewater or a liquid waste and is free of corrosivity to equipment.

The invention relates to a soft start control method of a power supply and a device thereof. The soft start control method is characterized in that after the power supply is started, an open loop is used for carrying out soft start; when output voltage of the power supply reaches a set value, a switch control mode is started, and under the switch control mode, an analog-digital converter converts the output voltage of the power supply into digital signals which are used as basis of whether to switch to closed loop control and adjust the output voltage; and a bit length utilization rate of the analog-digital converter is improved by utilizing the technology, smooth output voltage waveforms can be guaranteed, the maximum or the minimum overshoot under the switching mode can be avoided to the largest degree at the same time, and namely, transient response is restrained effectively.

A motor driving method is provided. A rotor position is determined based on whether or not a neutral point voltage difference, or a voltage difference between neutral point voltage and pseudo neutral point voltage exceeds a predetermined threshold when an energization phase is sequentially selected and energized. The energization phase for starting a motor is determined based on the result of this determination, and the motor is energized and started according to the determined energization phase. The operation mode is not changed directly from a step for searching the initial position of the rotor to a counter electromotive voltage mode. Instead, a search start mode for supplying appropriate rotational speed to the initial startup of the motor is once established, and then the mode is changed to the counter electromotive voltage mode. Following problems are solved: a problem of the correctness of a peak value of a position detection signal taken in; a problem of proneness to be influenced by a variation in motor characteristics caused by the slightness of differences in detection currents between phases; and a problem that methods of comparing voltage differences determined with respect to each group of measured voltages that occurs at a neutral point of motor windings each time a detection signal is applied to determine a large voltage difference require a reference table and high computing power.

The invention discloses a span-type steel structure platform for a bridge overhaul system, comprising a supporting device and an operating platform, wherein a linear sliding device is arranged on the operating platform, the operating platform slides on the supporting device through the linear sliding device, an overhaul trolley is arranged on the operating platform, and the operating platform is connected with a sliding driving device. According to the invention, by arranging the operating platform on the supporting device, the operating platform can be driven by moving the supporting device so as to realize segmented overhaul of a bridge; when the operating platform encounters a bridge pier, the operating platform slides to one side of the supporting device through the linear sliding device so as to avoid the bridge pier; and after the operating platform crosses the bridge pier, the operating platform slides to the reverse direction to reset so as to overhaul the bridge continuously. The device avoids the trouble of dismounting the overhaul device in the overhaul process when encountering the bridge pier, so that the overhaul period is greatly saved.

The invention discloses an aging rating method for 15Cr1Mo1V steel for a steam pipeline of a thermal power unit based on field detection for a hardness and a metallographic structure. The method detects the hardness and the metallographic structure of a material, and evaluates an aging level of the material correspondingly according to a detection result for the hardness and the metallographic structure. The method is simple, accurate and effective, a state of the material can be evaluated without damaging cut or sampling, and a metal inspector can be guided to accurately judge an aging degreeof 15Cr1Mo1V steel after high temperature service, thereby assisting a power plant to evaluate the service reliability of the material, and avoiding heavy accidents such as steam pipeline cracking due to severe aging of the material during operation of the power plant. The equipment of the power plant and the personal safety are effectively guaranteed, the maintenance period of the power plant isshortened, and the cost is saved.