As the core control system of a rolling mill, the hydraulic automatic gauge control (HAGC) system is key to ensuring a rolling process with high speed, high precision and high reliability. However, a HAGC system is typically a mechanicalelectrichydraulic coupling system with nonlinear characteristics. The vertical vibration of the load easily occurs during the working process, which ...
PROBLEM TO BE SOLVED: To provide a vertical roller mill enabling suppression of selfexcited : A vertical roller mill includes: a casing forming a classification chamber; a pulverization table housed below the casing and driven to rotate; a plurality of roller pressurization devices for pulverizing coal on the pulverization table by pressing pressure rollers against the ...
![[PDF] Vertical Vibration Control of Cold Rolling Mill's Rolls Based on ...](/qzl6ea0/71.jpg)
In this paper, a two degree of freedom nonlinear vertical vibration equation of the cold rolling mill with the dynamic rolling force was established, then the delay feedback control method was introduced into the equation to controlled the vertical vibration of the system.
Especially, the vertical vibration of rolls directly effects the exit thickness of strip. In order to restrain vertical vibration of rolls and improve stability of rolling process, the active control theory and technology has been used and to control the vertical vibration phenomenon. Zhang adopted the robust theory to control the strip tension ...
The vertical roller mill has high energy efficiency and the installation space is smaller compared with tube mills. These days, the vertical roller mills have been widely adopted. A）Structure (1) The rollers are hydraulically pressed against a disc table and the feed is ground between the rollers and the disc table.
In this paper, vibration characteristics of a Vertical Roller Mill (VRM) are studied by using physical parameters of an operating VRM. The mathematical model is derived and simulated for a set of working parameters. Mechanical properties of the grinding material and the physical properties of the mechanical construction are used in the vibration model in order to obtain more realistic results ...
The vibration demolding of the crystallizer leads to slab thickness deviation in continuous casting processes. Therefore, in this paper, the dynamic model of the hot strip rolling mill vibration resulting from entry thickness deviation is proposed and its dynamic characteristics are studied. First, the dynamic model of vertical vibration in the hot strip rolling mill is established based on ...
When the material layer is too thin, the feeding amount should be increased to increase the equipment pressure difference, stabilize the material layer, and reduce equipment vibration. If the material layer is too thick, you should immediately reduce the amount of feed and increase the amount of ventilation to ensure a smooth discharge system.
1. Introduction. The vertical roller mill (VRM) is heavy mechanical equipment that used in the cement materials industry to process cement, slag, and coal cinder (Pani Mohanta, Citation 2015).The equipment always needs to work in the environment of heavy load, high temperature, high pressure, high corrosiveness, electromagnetic radiation interference, and multifield coupling, thus it is ...
In recent years vertical roller mill (VRM) has proved to be a popular choice for finished cement grinding due to low power consumption but it is also very sensitive to vibrations and can deteriorate productivity if process optimization is varied slightly.
re vibration vertical roller mill. There are a number of reasons for high vibrations in vertical roller mills, such as: 1. Failure of the grout or cement material under the steel beams embedded in the foundation top, which allows oil to penetrate, further degrading the concrete. The anchor bolts, which are typically large in diameter, continue ...
Request PDF | Vibration Analysis of a Vertical Roller Mill: Modeling and Validation | In this paper, vibration characteristics of a Vertical Roller Mill (VRM) are studied by using...
This study establishes a verticalhorizontal coupling vibration model of hot rolling mill rolls under multipiecewise nonlinear constraints considering the piecewise nonlinear spring force and piecewise nonlinear friction force constraints of the hydraulic cylinder in the vertical direction of the rolls, the piecewise stiffness constraints in th...
When vertical roller mill is in normal operation, its vibration is weak. When the mill is vibrating strongly, it should be stopped and checked to ensure the equipment is working properly. There may be some reasons for the excessive vibration, and the cause should be analyzed: The upper layer of grinding disc is too thin or too thick;
Vertical roller mill is suitable for the largescale processing of nonmetallic mineral powders below 1250 mesh. Its largescale and energysaving effects are significant. ... causing vibration. ... The control of moisture content of raw material is very important for the stable operation of vertical roller mill. If the moisture content of the ...
This article, based on the abrasion condition of the rollers on the working field, analyzes the movement characteristics of the material layer of the vertical roller mills from several aspects, such as the tangent speed difference between the roller and the grinding table, the "piles up" phenomenon as well as the flow forms of the material layer. Then we further studied the influence of the ...
This paper studies the torsional vibration suppression control problem for the nonlinear rolling mill main drive system with performance constraint requirements and unknown measurement sensitivities. Firstly, considering the nonlinear friction between the roll gaps, a torsional vibration model of the main drive system of rolling mill is established. Then, with the asymmetric performance ...
quadropol® vertical roller mill thyssenkrupp is one of the few fullrange suppliers for the cement industry from individual machines, all the way up to complete cement plants, and this since decades. The market requirement is easy to define. Present kiln lines have capacities of up to 10,000 tons per day.
Rolling mill vibration is a worldwide problem, although it has been found that the mill structure defects are the main cause of vibration, but the inhibition measures are difficult to implement. So we discussed the rolling force parameters influence on rolling mill vibration and suppression measures from rolling technology in this article. The results show that the rolling force is increased ...
How do you reduce vertical roller mill vibration? gkmill News Adjustment of Grinding Pressure The central control operator should pay attention to the feedback value of the grinding pressure in time. When the grinding pressure is lower than the set pressure, it should be filled with nitrogen immediately to increase the grinding pressure.
The lower rocker arm is an important part of the vertical roller mill and its lightweight design is of great significance for reducing the mass and production cost of the roller mill. Firstly, the strength and deformation distribution of the lower rocker arm under working load were analyzed by ANSYS Workbench to determine the maximum stress and maximum deformation. The parts with large ...
Air leakage of the system. Air leakage of the mill body is bound to cause small pressure difference, insufficient wind speed, making the powder cannot be taken away in time, affecting the output capacity of vertical roller mill. In addition, air leakage in other parts of the system will also reduce the wind speed, which will cause the ...
Firstly, based on the deterministic vertical vibration model of a fourroller cold rolling mill under harmonic excitation, a stochastic vertical vibration model of a fourroller cold rolling mill with random fluctuation as Gaussian white noise is introduced.
Dynamic Model. The rolling mill drive system mainly consists of the motor, reducer, main shaft, speed divider, arc gear shaft, work roll and bearings at corresponding parts [].The torsional vibration is often closely related to the dynamic energy transformation process of the rolling interface, which causes the relative speed between the strip and work roll change on the rolling interface.
VRM construction, its process and parameters which affects the performance and productivity of vertical roller mill are discussed. Also the consequences of variations in parameter explained.
Vertical Roller Mills. Optimization of VRM Operation Do not believe screen values unless you have checked them Continuously change Process Parameters and document results to find Optimum Optimum is highest capacity at lowest power consumption Be sensitive to changes of feed material and adapt parameters Focus on Relevant Process Parameters only Optimize Control Loops
grindability affects the capacity of grinding, type of mill and roller pressure. The capacity of the mill is calculated Using G K * D Where, G is capacity of the mill, K1 is roller mill coefficient and D is table diameter. 2. PROCESS CONTROL OF VRM The conventional control system of VRM composed of field staff to adjust the few process
Comparison of Figures indicates that the two ranges of, namely, N < < > 5 N, can cause severe vibration of rolling mill rolls in the vertical and horizontal directions. In this study, a coupled vibration model of hot rolling mill rolls under the effect of multiple nonlinear forces was established.
As a result of the higher ∆Pmill, the mill vibration increases. (8 10mm/s), which results in a good opportunity to test the effect of the grinding aid. In contrast to tests with ball mills, the effect of grinding aids in a VRM is already visible and audible after 10 20min. Table 1: Data used to produce Figure 3.
Overview Products What we offer Customer stories Vertical roller mills offer supreme grinding with high energyefficiency Whether grinding raw coal, clinker, cement and/or slag, we have a VRM solution to suit your grinding needs.
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