The article examines the influence of various superplasticizers on the performance characteristics of concrete. A series of tests of samples-beams of fine-grained concrete modified with plasticizers of various types was carried out. The optimal amount of the introduced additive was experimentally determined to compare the plasticizing effect of the cement-sand mixture. Experimental data are given indicating the main operational characteristics of the material depending on the additive used. The most effective additive "Polyplast SP-3" has been determined.
Keywords: concrete, fine-grained concrete, mixture, lignosulfonates, polycarboxylates, naphthalene sulfonates, plasticizer, superplasticizer, water demand, plasticity
The paper analyzes and shows the inadequacy of the technology for repairing production wells by rolling out a corrugated metal patch with a dornating device, which consists in premature violation of the tightness of the well due to low strength of the connection. A technology and a hydromechanical device for additional fastening by radial extrusion of spherical cavities in the metal of the plaster are proposed. As a result, a drag force is generated in the cross-section of the fastener, which prevents shear loads from axial forces. Strength calculations have shown that for better performance of the metal patch, it is advisable to increase the shear resistance force by increasing the number of punches or technological transitions of fastening.
Keywords: casing, production string, well tightness, metal plaster, radial extrusion, strength
The paper presents the properties and nomenclature of products made of ceramic fiber used for insulating lining in steam reforming furnaces. On the example of the lining of the radiant chamber, the technology of mounting ceramic blankets on anchor studs, which is currently used in the construction and repair of reforming furnaces, is considered. The shortcomings of the existing technology are noted. These include the complexity of the process, the complexity of installation control and the high probability of uneven thermal conductivity of the lining surface due to hidden defects, as well as the spraying of ceramic fiber particles in the air that cause diseases. The nomenclature and technology of installation of insulating lining with ceramic blocks along guide tubes with subsequent resistance welding with the camera body is proposed. The technology will reduce the repair time, improve the thermal conductivity of the camera, reduce the risk of diseases.
Keywords: gas reforming, radiant chamber, insulation lining, ceramic fiber, thermal conductivity of the furnace
In industrial production, stacker loaders used for loading and transporting goods packed on pallets are quite widely used in warehouse work. Basically, when performing a loading and transport technological operation, the functionality of the stacker is sufficient. When an obstacle appears or pallets are stacked, additional maneuverability is required, as a result of which the overall performance of the loader is lost. As a result of the conducted research, it was found that when bypassing obstacles and laying pallets, the time spent on maneuvering the chassis is up to 13%, while the utilization factor of the loader-stacker in terms of productivity is 0.7. Numerical modeling of the positioning process of the load-handling body of the loading and transport unit was carried out, on this basis, the design of a loader-stacker with expanded functionality was proposed and developed, in particular, the service area increased due to the use of a tripod manipulator and two guide actuators, which reduces the time of the technological operation of loading and unloading pallets in warehouse work. Geometrical, structural and kinematic parameters of the loader mechanism are calculated.
Keywords: numerical simulation, loader-stacker, service area, lifting body, manipulator, hinges, chassis, structural analysis, geometric analysis, kinematic analysis, executive drive, pallet
The technology of well cleaning using the KOS-02 complex and a multifunctional tool that has the ability to reciprocate and rotational motion. The scheme of force effect of the cleaning tool is given and the power parameters of the process are estimated.
Keywords: destruction of the face zone, sand plug , equipment for cleaning wells, cleaning tool, flushing technology
The results of theoretical research and analysis of methods that will significantly reduce the weight of the gravity oil platform are presented. At the same time, its static, dynamic, and shear stability will remain under the influence of wind, wave, ice load and current load. In order to reduce the weight and overall dimensions, it is proposed to outline the lower part of the platform base with a metal sheet pile wall. As a result of theoretical studies, the dependence of the shear force under the influence of external forces acting on the platform during operation on the physical and mechanical properties of the soil and the size of the sheet pile wall is found, which will significantly reduce the weight of the platform and the cost of its construction.
Keywords: gravity oil platform, shear stability, tongue-and-groove wall, external forces acting on the platform, rollover stability