Study on the determination of the parameters of the electric purifier

The article is devoted to the determination of the parameters on which the filter performance depends on the hydrodynamic, electromagnetic and geometrical parameters of the fluid and pollution. These include fluid viscosity and flow rate, magnetizing force, particle size of contamination, gap height, and the distance between the turns.

Study for a Wall-Climbing Robot Magnetic Attraction Force of An Electronically Controlled Permanent Magnet

With the advancement in science and technology, a wall-climbing robot attached to the ship's outer surface is increasingly replacing humans in the rust removal. The magnetic force is not just the adsorption force but also the moving resistance force, which is currently the technological bottleneck in wall-climbing robotics based on magnetic adsorption. This paper proposes a novel wall-climbing robot based on electrically controlled permanent magnet technology to solve this problem. An electrically controlled permanent magnetic wall-climbing robot is proposed to realize the function of magnetization and demagnetization by changing the pulse current. The results of the experiments reveal that the magnetizing force is adequately adsorbed on the ship's outer surface. The magnetic attraction force is close to 0 N during demagnetization, meaning that the system is fully unloaded, as predicted by the theoretical analysis.

METHODOLOGY OF DETERMINATION OF THE OF MULTIFREQUENCY MAGNETIC FIELD LEVEL AT WELDER`S WORKING ZONE

The purpose of this work is to develop a methodology for determination of the total level of multifrequency magnetic field (MF) at the working area of welder by studying the dependences of the magnetizing force of its individual harmonic components to the electrical characteristics of the MF source and welding modes. The study was carried out at a wide frequency range of the MF action for the researching of dependences to MF technological parameters of the contact welding machine and the distance to it. An induction magnetic field sensor and a digital recording oscilloscope with a fast Fourier transform function were used for experimental studies of MF magnetizing force and their spectral ranges. Based on the analysis of the obtained MF oscillograms and spectrograms, the shape and magnitude of the MF magnetizing force signals in different frequency ranges were established. Since it is impossible to quantify the overall level for a multifrequency MF with taking into account all the harmonic components of the MF simultaneously, the generalized magnetic field level indicator (MFI) was proposed, which became the basis for its use as a methodology for the assessment of MF impact on human body. The use of the proposed methodology allowed to establish that it is generated MF with harmonic components in the frequency ranges 5-50 and 50-1000 Hz at working area under contact spot welding, which may exceed their maximum allowed levels, leading to the respective increase of MFI level. It was established that any changes in the mode of contact spot welding, compared to the mode of welding with one batch of full-phase pulses of welding current, lead to the increase in MFI with exceeding of maximum allowed level at a distance of 800-1000 mm from the axis of contact welding machine electrodes; modelling of the front and trailing edges of the pulse lead to the reduction of MFI level, while increasing the angle of phase control of the heating mode leads to the increase of MFI level. The proposed methodology can be applied as universal both for hygienic assessment of the electromagnetic environment during arc welding and for other electrical equipment. The developed methodology gives possibility to assess the overall impact of multifrequency MF on human body. It is based on the known laws of electrodynamics using a new generalized indicator - magnetic field level indicator MFI.

DEVICE FOR RESEARCHES OF MAGNETIC FIELD IMPACT UPON “WHEEL-RAIL” FRICTION PAIR CHARACTERISTICS

The paper is dedicated to the circuit diagram substantiation of the specialized roller bench for researches of the magnetic field impact upon wheel adhesion with a rail. On the basis of the analysis of the experimental plants available at present for the study of the contact interaction of wheels with rails it is defined that two-roller benches are the most efficient for the investigation of different outer factors impact upon wheel adhesion with a rail. Taking into account mentioned above there is offered an original design of the two-roller bench equipped with the device for friction area magnetization. Two cylinders with parallel axes are theoretically a friction pair. Taking into account the presence of a non-concurrency arisen at roller manufacturing and mounting a point contact is realized in the bench. A bench formation is carried out according to a modular approach with the installation of rotary magnetic conductors. For the support of the largest magnetization of a friction area in longitudinal and transverse directions and for the decrease of stray flux in the bench there is realized a series connection of roller friction area with the sources of a magnetizing force. For the substantiation of rotary magnetic conductor position choice regarding a friction area of bench rollers there is carried out an analysis of magnetic field distribution in the friction area depending on the location of magnetic conductors. On the basis of the investigation results it is defined that a change of magnetic conductor position changes the orientation of a magnetic field vector, at that a roller friction area is magnetized in transverse and longitudinal directions. In view of this the bench design offered allows investigating the impact of longitudinal and cross magnetic fields upon friction in the contact of a wheel with a rail. Furthermore, it is defined that at small values of an angle between the direction of a magnetic field vector and the plane of a roller friction area a possibility to exclude the effect of roller magnetic additional loading appears.

Calculation of the Magnetomotive Force of Control Coils of Actuators with Different Current Directions

The article is devoted to solving the actual problem of synthesis of actuators based on materials with a form memory effect. An actuating device with a distributed control coil and an active element made of such ma-terial is considered. It is shown that the characteristics of the device do not depend on the direction of the mag-netic field providing deformation. Not only the magnitude of the magnetizing force but also the direction of current in the windings of the distributed control coil has a significant influence on the process of re-magnetizing the active element. It is advisable to use alternating current direction in control coils of actuators to save electric energy

Algorithm for Calculating the Basic Optimal Parameters of Magnetic Devices of Telecommunication-Information Control Systems

For calculating magnetic devices of telecommunication –information control systems used the optimal directed graph. On the based the directed graph defining optimal parameters of magnetic devices: complex magnetic resistance, optimal value, complex size of magnetizing force of the coil and other.

DYNAMIC CONDITIONS OF COMPENSATED SYNCHRONOUS MACHINE

The dynamic behavior of synchronous machine with longitudinal-transverse excitement by maintenance of the rotor overhang corner as equal zero are considered. The given condition is named as compensated and correspond with full compensation of transverse armature reaction by magnetizing force of transverse excitement winding. In such machine is absented the limit of steady-state overload, but active and reactive components of load current are concurrent as projections of load current image vector on orthogonal axes of machine inductor. The research aim is a determination of steady-state stability criterion of compensated synchronous machine working on powerful electrical system. The researches are organized in assumption of inductor current invariance and at neglect of stator windings time constant. The electromagnetic moment expression of longitudinal-transverse excitement synchronous machine in compensated work condition is received as a result of analysis of the spatial vector diagrams and equations. The expression analysis has allowed to find the criterion of rotor creepage stability and to examine the steady-state stability of the machine in different work conditions. It is shown that machines stability factor is defined by not only the reactive power of machine short circuit, but also associated reactive power.

Development of electromagnetic stirring system at modernization ofhorizontal continuous caster

Horizontal state of mold at continuous casting of steel in horizontal continuous casters (HCC) complicates the melt supply conditions and forming of billets, results in disturbing ofcasting process stability, in forming of zones of chemical and physical inhomogeneity, distortion of the billet geometric form, arising of longitudinal fractures, bleeding at the mold exit. A possibility to increase the quality of the billets, produced at HCCs relates to changing of conditions of the metal solidification, creation of forced melt movement, in particular, by application of electromagnetic field. To increase the casting stability andimprove quality of the billets from alloyed steels a modernization of a HCC accomplished. Within the modernization a system of electromagnetic stirring (EMS) for modernizedmold of the HCC was developed. The modernized mold for horizontal casting is equipped by a build-in two-phased stator of alternative current. The two phased EMS stator built-in into the mold shell, supplied by power from two-phased frequency convertor, developed and manufactured by “Electroprivod i silivaya electronica” LLC (Moscow). A water immersion winding is the main element of the EMS stator. The winding isolation resistance at the first stage of the water immersion stator running was more than 500 m ohm. The technology of the winding manufacturing provides a high coefficient of heat exchange between the copper wires and technical water, usedfor direct cooling. By this, high values of the winding magnetizing force is reached at a small volume that in its turn provides a wide range of stirring intensity control. The developed EMS system enables to decrease considerably the existing drawbacks of HCC.