scholarly journals Dynamic processes modeling in a peristaltic concrete pump with a hydraulic drive

2020 ◽  
Vol 0 (89) ◽  
pp. 15
Author(s):  
Vladimir Shatokhin ◽  
Boris Granko ◽  
Vladimir Sobol
Keyword(s):  
Hydraulic Drive ◽  
Dynamic Processes ◽  
Concrete Pump

scholarly journals VIBRATION PROCESSES MODELING IN A PERISTALTIC CONCRETE PUMP WITH HYDRAULIC DRIVE

2020 ◽  
pp. 22-32
Author(s):  
Vladimir Shatokhin ◽  
Boris Granko ◽  
Vladimir Sobol
Keyword(s):  
Hydraulic Drive ◽  
Dynamic Processes ◽  
Variable Component ◽  
Significant Variable ◽  
Hydraulic Motor ◽  
Friction Forces ◽  
Average Speed ◽  
Pump Rotor ◽  
Resistance Torque ◽  
Concrete Pump

The research results of the mathematical model development of dynamic processes in a peristaltic concrete pump with a hydraulic drive are presented. Cast concrete occupies a leading place in modern construction. Peristaltic concrete pumps are good proved in this area. Developing of devices for performance of such activities is an actual task. One of contemporary efficient directions in its solving is an adequate modeling of dynamic processes in mentioned devices. The model is development in the form of a differential equation for rotation angle of the pump rotor; contains general geometric characteristics, rotor’s mass characteristics, dynamic characteristics of the hydraulic motor, parameters of the hose and a structural mix. A method has been developed for the resistance torque forming to rotation of the pump rotor from rollers deforming the hose. A model of the friction forces during the movement of the structural mix is proposed. An expression is obtained for the resistance forces as result of gravity forces action on the mix particles in the outlet part of the hose. An approach is proposed for using catalog data to represent the torque of a hydraulic motor as a function of the angular velocity of its rotor. Researches of dynamic processes by using the proposed model are carried out. Important technological regularities of the unit functioning have been established, in particular: the mortar speed may have a significant variable component; the mortar speed and the pump performance increase with a decrease in the length of the outlet hose and a decrease in its height, a decrease in the rolling friction coefficients for the rollers, and not using of the side rollers. The conducted research show that an increase of an altitude leads to a decrease in the average speed of the mixture and the frequency of pulsations. In this case the amplitude of velocity pulsations increases. With an increase in the length of a deferent hose, the amplitude of velocity pulsations changes insignificantly. The rejection of side rollers leads to an increase in the average speed of the mixture motion with minor pulsations. The walls of the hose, however, in this case experience more intense bending stresses, which reduce the product life of the hose.

Modeling of the Supplying Process of Building Mixture by Using of Peristaltic Concrete Pump

2018 ◽  
Vol 38 ◽  
pp. 46-59 ◽  
Author(s):  
Denys Chayka ◽  
Inga Emeljanova ◽  
Alexsander Grigoryev ◽  
Pavel Andrenko
Keyword(s):  
Hydraulic Drive ◽  
Operating Parameters ◽  
Flexible Hose ◽  
Operating Modes ◽  
System Pressure ◽  
Basic Parameters ◽  
Torque Values ◽  
Concrete Pump ◽  
The Impact ◽  
General Service

Presently constructors use peristaltic concrete pumps for wet shotcreting processes or for transferring the building mixes to the place of their deposit. Fitting the flexible-hose concrete pump with a hydraulic drive allows both making the range of its operating modes much broader and enhancing its reliability. Numerically simulated models of the building mixes feeding processes were developed to design a hydraulic drive to fit the general-service flexible-hose concrete pump and to calculate its basic parameters. Simulation of the building mixes feeding processes gave the characteristic curves of the concrete pump operating parameters, determined the time of ramping the concrete pump up to the steady running mode, and estimated the impact of the transferred mix density and viscosity to the maximal system pressure, supplied power and torque values.

scholarly journals Mathematical model of the volumetric hydrodrive’s dynamics, sensitive to the loading variation

2018 ◽  
Vol 224 ◽  
pp. 02100 ◽  
Author(s):  
Alexandra Ivanovskaya ◽  
Vladimir Popov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Characteristic Feature ◽  
Hydraulic Drive ◽  
Drive System ◽  
Operating Principle ◽  
Dynamic Loads ◽  
Dynamic Processes ◽  
Hydromechanical System

The paper deals with the problems of mathematical modeling of the dynamic processes proceeding in a complex hydromechanical system of the ship’s deck load-lifting devices. The characteristic feature of this class of equipment is the operation in special conditions, i.e, under the influence of external hydrometeorological factors, taking into account variations in the parameters of lifted or lowered cargo. With a view to gradual regulation of the change of torque on the working drum to reduce dynamic loads, it is offered to use a hydraulic drive that is sensitive to the variation of loading. The operating principle of the considered volumetric hydraulic drive is described. The received mathematical model allows to establish influence of the hydrodrive parameters on transients in a drive system.

Surface reactions observed by photoemission electron microscopy (PEEM)

1992 ◽  
Vol 50 (1) ◽  
pp. 286-287
Author(s):  
H.H. Rotermund
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Work Function ◽  
Chemical Reactions ◽  
Reaction Diffusion ◽  
Dynamic Processes ◽  
Clean Surface ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Photoemission Electron

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.

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