36 results about "Tension reduction" patented technology

An apparatus for treatment of a failing heart by reducing the wall tension therein. In one embodiment, the apparatus includes a tension member for drawing at least two walls of a heart chamber toward each other. Methods for placing the apparatus on the heart are also provided.

The invention relates to a total saponnis extraction technology of a honeylocust extract and an application field thereof. The total saponnis extraction technology is characterized in that the total saponnis is a plant source nonionic type surface active agent, and has the interfacial tension reduction property, emulsion activity, wetting property, temperature-resistant and salt-tolerant property, dispersant solubilizing and the like, so as to provide the applicability in the fields of recovery, storage and transportation of crude oil; the green surface active agent from the plant, namely the honeylocust, is applied to the bulk industrial purpose, so the resource utilization rate of the honeylocust is improved, the recovery rate of crude oil is improved, the storage and transportation cost of crude oil is reduced, and the pollution to the environment is reduced.

Devices and methods for treatment of a failing heart by reducing the heart wall stress. The device can be one which reduces wall stress throughout the cardiac cycle or only a portion of the cardiac cycle.

The invention discloses a band steel return control apparatus after the shutdown of a continuous annealing furnace. The apparatus comprises a mode selection device, an execution mechanism, an automatic tension control mechanism, an automatic time control mechanism and an operation table, wherein the mode selection device can select one of an automatic tension mode, an automatic time mode and a manual mode; the execution mechanism indicates equipment of the continuous annealing furnace to execute a band steel return operation or a tension reduction operation; the automatic tension control mechanism controls the execution mechanism to gradually reduce the tension of the continuous annealing furnace in time period; the automatic time control mechanism controls the execution mechanism to uniformly return the equal-length band steel with the work segment as a base in time period; and the operation table receives a manual operation instruction, and controls the return operation of the execution mechanism to be carried out according to the manual operation instruction when the mode selection device selects the manual mode. According to the invention, the band steel can be automatically returned to the furnace after the abnormal shutdown of the technical segment of the continuous annealing furnace, so problems comprising band breakage, furnace deformation, furnace roller displacement and the like can be effectively prevented.

The invention discloses a control method for restart of a strip steel processing line furnace area after shutdown. The control method is characterized in that an annealing furnace comprises an entrance preheating section, a heating section, a soak section, a cooling section, a superheating section and a final cooling section, and a process set value of normal production is multiplied by a certain coefficient according to different work conditions, so that the purpose of speed and tension reduction is achieved. The control method has the benefits that overburnt strip steel passes through the annealing furnace smoothly, strip breakage and hot waved surfaces of the strip steel in the annealing furnace are reduced or prevented as far as possible, and a unit can recover the normal production rapidly and stably.

The invention provides a structural system for reducing prestress before tension reduction of prestressed reinforcement, which consists of a novel fixing end capable of being repeatedly assembled and disassembled and a tensioning end structural system. In the structural system, when the design value of the tensile strength of the prestressed reinforcement is reached, before reducing tensile force and removing clamping pieces, the tensile force of the prestressed reinforcement is reduced in advance, before the final tension reduction, the pulling force value of the prestressed reinforcement is reduced until the material elongation generated by the left tensile strength value is enough for successful tension reduction, thereby fully utilizing the strength design standard value of the prestressed reinforcement, improving material utilization ratio, reducing the consumption of the prestressed reinforcement, reducing the structural specification of the whole structural system including the fixing end and the tensioning end and a prestressed reinforcement pore path; the unsuccessful tension reduction and the failed repeated use of the prestressed reinforcement caused by the beyond-the-limit working pulling force of the prestressed reinforcement are avoided; and the structural system provides new technological conditions for the non-bonding after-tension method prestress structural system used for the combination and disassembly of concrete precast components to save resources and lower cost.

In chain and sprocket systems with at least two resonance modes, two or more tension reducing sprockets are oriented to cancel each other at a first resonance mode and have no effect to increase tensions at such first resonance mode. The tension reduction sprockets, however, are oriented with each other so that tensions will be reduced at a second resonance mode. Hence, two or more tension reducing sprockets are used to reduce tensions at a second resonance mode from sources outside the chain and sprocket system while minimizing tension increases at first resonance mode.

In chain and sprocket systems with at least two resonance modes, two or more tension reducing sprockets are oriented to cancel each other at a first resonance mode and have no effect to increase tensions at such first resonance mode. The tension reduction sprockets, however, are oriented with each other so that tensions will be reduced at a second resonance mode. Hence, two or more tension reducing sprockets are used to reduce tensions at a second resonance mode from sources outside the chain and sprocket system while minimizing tension increases at first resonance mode.

The invention discloses a packing material tension keeping structure comprising a guide roller and a speed limit mechanism. The guide roller and the speed limit mechanism are arranged on an external packer which comprises a supporting rod, a hand wheel, a connecting rod and a down-pressing device, one end of the supporting rod is hinged to the down-pressing device through the connecting rod, and the other end of the supporting rod is in threaded connection with the hand wheel. The guide roller and a roller of the external packer are spaced by a certain distance to enable a packing material to keep certain tension. The rotating speed of the roller of the external packer can be controlled through the speed limit mechanism, and speed limit effect is achieved. The hand wheel is rotated to drive the supporting rod to rotate, and the down-pressing device moves up and down under the linkage action of the connecting rod. When the down-pressing device moves downwards, the speed of the roller is limited, and tension reduction of the packing material due to too fast rotation is avoided; when the down-pressing device moves upwards, limit to the speed of the roller is reduced, and feeding requirements of quick packing of the packer can be met.

The invention discloses a manufacturing method of L80-13Cr oil pipes. The manufacturing method comprises the steps of pipe blank heating, steel pipe penetration, tandem rolling of steel pipes, reheating of the steel pipes, tension reduction of the steel pipes, air hardening, tempering heat treatment, straightening of the pipes, cutting of heads and tails of the pipes and segmenting of the pipes. In the step of reheating the steel pipes, the heating temperature of the steel pipes is 960-1000 DEG C; in the step of tension reduction of the steel pipes, the temperature of the steel pipes after tension reduction is higher than 850 DEG C; and in the step of tempering heat treatment, the tempering temperature is 760-800 DEG C. Due to the adoption of the manufacturing method of the L80-13Cr oil pipes, the production cost of the products is obviously reduced while the productivity is substantially increased; and the mechanical property of the L80-13Cr oil pipes manufactured by the method can meet the API SPEC 5CT standard; and the impact toughness of the L80-13Cr oil pipes can be equal to and even substantially higher than that of the pipes subjected to common oil quenching or air quenching and tempering treatment.

The invention provides a controlled rolling method in a seamless pipe hot rolling process. According to the method, the following data are used for design: a perfect recrystallization temperature lower limit, a non-recrystallization temperature upper limit, temperatures of an inlet and an outlet of a perforator for rolling seameless pipe of the target specification by the conventional process on a production line planned to use, an inlet and an outlet of a pipe rolling machine and an inlet and an outlet of a tension reduction / sizing machine as well as rolling hole patterns for perforation, pipe rolling and tension reduction / sizing. A controlled rolling process is designed according to acquired data. The controlled rolling method comprises the following steps: performing rolling deformation adjustment and rolling temperature design by taking the two steps of perforation and pipe rolling as rough rolling and the step of tension reduction / sizing as fine rolling, and controlling the finish rolling temperature of rough rolling and open rolling temperature of fine rolling by a certain method to finally realize the controlled rolling process. The controlled rolling method has the beneficial effects that the microscopic tissue of the hot-rolled seamless pipe is improved, and the comprehensive mechanical property, particularly the impact strength, of a finished product pipe subjected to thermal treatment is improved. The properties of both 23Mn2SiCrV high-strength steel and ultralow-temperature 9Ni steel can be obviously improved by the use of the controlled rolling process.

Devices and methods for treatment of a failing heart by reducing the heart wall stress. The device can be one which reduces wall stress throughout the cardiac cycle or only a portion of the cardiac cycle.