Rotating Steel Cylinder Research Articles

Energy Efficient, Highly Precise Cascade Dryness Control for Fibrous Tape by Induction-Based Surface Heating of a Rotating Steel Cylinder with Moving Inductors

Drying various materials constitutes an essential component of several industrial processes, e.g., paper production. Typically, rotating cylinders heated internally by water steam are used for drying tape-shaped material in paper-making machines. Such an approach remains very energy-consuming, while the whole process is expensive and in conflict with the global policy of reducing energy consumption in heavy industry. One promising alternative method of drying fibrous tapes is the induction heating of drying cylinders. In this paper, we propose a drying system based on a set of inductors (electromagnetic field sources) that generate energy in the mantle of the cylinder and dry the running tape. By enabling the movement of the inductors, the system provides a high level of flexibility in terms of reacting to the varying humidity of the tape. Additionally, imaging the temperature field on the cylinder surface provides a supplementary source of information, enabling the temperature profile to be controlled. Two types of humidity control systems, a one-loop feedback control and a cascade control, were designed and analyzed. Simulation analysis and experimental verification performed using a semi-industrial setup proves that using the proposed cascade control ensures more than 30% faster response of the whole dryness control system.

Compensation of heat power generation delays in the induction heating system of a rotating steel cylinder

Compensation of heat power generation delays in the induction heating system of a rotating steel cylinder

Developing of Polypyrrole Coating on Rotating Steel Cylinder for Improving its Corrosion Resistance

This work investigates the possibility of using polypyrrole (PPy) coating for improving the corrosion resistance of rotating cylinder subjected to saline solution. Galvanostatic technique was used for layer formation under different conditions of current density, pyrrole monomer concentration, sodium tartrate concentration and solution pH. The potentiodynamic technique was used for examination of PPy coated steel in corrosive medium composed of 3.5%NaCl under different rotating speed ranging from 200 to 1000 rpm. The formed PPy layer was investigated for its corrosion resistance using 3.5% NaCl solution under different rotational speed using the potentiodynamic technique. The preliminary results showed that coating steel with polypyrrole layer under different rotational speed can improve its corrosion resistance by a factor ranging from 1.2 to 1.88 depending on the operating conditions

Control Algorithms for Inductors Movement in Induction Heated Calenders

Abstract Fixed, placed at regular distances inductors for induction heating of a rotating steel cylinder do not provide sufficiently uniform temperature profile along cylinder axis required by modern technologies,. The article examines the influence of inductors movement along the cylinder axis on the reduction of pick-to- pick temperature amplitude.

Using Infrared Camera for Dynamic Properties Identification of Induction Heated Rotating Steel Cylinder

Abstract Using of precise temperature control method requires knowledge of the dynamic properties of the controlled system. It can be determined by applying infrared camera to the temperature measurement of controlled system. The article presents two models of induction heated rotating steel cylinder and the method of their parameters estimation.

Fuzzy Spatial Relations-Based Markers Location on Images From an Infrared Camera

Abstract The following paper presents a fuzzy assessed spatial relations-based approach to detect a set of visual markers on a rotating steel cylinder previously discussed by the authors. Presented algorithm uses fuzzy inference system based on fuzzy assessed objects’ shape, orientation and mutual relative position in an input image.

J042021 回転体の非接触温度センシングヘのレーザー超音波の適用

In this work, a novel ultrasonic method for monitoring temperature distributions of a rotating object has been proposed. The method provides noncontact measurements of surface and internal temperature distributions of a rotating object using a laser ultrasonic technique. The principle of the method is basically based on a combination of temperature dependence of ultrasonic velocity for surface acoustic wave (SAW) of an axial symmetric heated columnar and its heat conduction analysis. First, the validity of the propose method is numerically verified for a steel cylinder model being uniformly heated up to 120 ℃. Next, the ultrasonic method has been applied to the internal and surface temperature measurements of a rotating steel cylinder of 100 mm diameter while the outer surface is being heated up to 120 ℃. Internal temperature distributions are estimated from the measured ultrasonic waves and its variation during heating is monitored.

Developing of Polyaniline Coating on Rotating Steel Cylinder for Improving Its Corrosion Resistance

Developing of Polyaniline Coating on Rotating Steel Cylinder for Improving Its Corrosion Resistance

Evolution of Cardiopulmonary Bypass

At the end of the Second World War, the devastation of many cities in Europe, combined with the problems of reconstruction and loss of financial support, had brought European medical research to a halt. On the other hand, in the United States the war brought about an enormous amount of scientific research through the development of nuclear weapons, the mass production of penicillin, early computers, and a variety of other technological advances, some of which were eventually put to use by medical investigators. In the immediate postwar years, Congress began 3 decades of generous funding for medical research and education through the National Institutes of Health and the Public Health Service. In the 1920s and 1930s, medical research money had been scarce, but after the war there was a flood of money. The National Institutes of Health budget for medical research in 1945 was $180 000. By 1947, it was increased to $4 000 000, in 1950 to $46 000 000, and in 1974 to $1 billion.1 By 2008, the total budget just for the Heart, Lung, and Blood Institute was almost $3 billion. Since colonial times, it had been customary for young American physicians to spend postgraduate time in Vienna, Berlin, London, or Paris. Now the opposite was true. It became important for a young European physician to have worked for a year or so in a US medical center. The world center for medical education and research had shifted from Europe to the United States. Postwar medical progress was also stimulated by several other programs. The Hill-Burton act of 1946 provided funds for community hospital upgrades and construction. Initially this bill provided $75 million per year for 5 years. It was a matching plan in which local hospitals were required to raise two thirds of the new …

Comparative potential of alternative wood welding systems, ultrasonic and microfriction stir welding

Two alternative welding systems were evaluated for wood welding. Ultrasonic welding produces joints of good strength but it appears to be applicable only to thin wood pieces. It does not appear that further possible process improvement could bring the joint strength to a structural level. Microfriction stir welding does show potential for welding continuously wooden plates without any limitation on length of wood pieces. The strength of the weld obtained was low due to the limited depth of the weldline. Optimisation of parameters is necessary. A drawback at present appears to be the limited thickness of the wooden pieces that can be welded. X-ray micro densitometry, scanning electron microscopy and optical microscopy showed that the main difference compared to the other techniques is that in the microfriction stir weld, there is a veritable welded line of molten material. This molten material comes from the wood in contact with the rotating steel cylinder, which has flowed down in the micro gap between the two pieces of timber where it has bonded by solidifying.

Mm wavelengths complex Doppler analysis using dark field illumination

Experimental results that indicate that at least two fundamental modes of Doppler generation are present when a rotating steel cylinder is broadside illuminated by radar. Improvised bistatic measurements at 77GHz are discussed and second order Doppler effects studied. Complex Doppler returns, consisting of two or more Doppler contributions, are decomposed and studied using empirical methods. In particular, ground illumination techniques are used to study Doppler in the shadow region of a cylinder of circumference 81 wavelengths. It is concluded that the complex Doppler response from the spinning cylinder consists of both direct (first order) and delayed (second order) Doppler components. Further measurements are proposed to study the delayed Doppler effect further.

Experimental characterization of a low-current cutting torch

An experimental characterization of a low-current (30-40 A) cutting torch is presented. To avoid contamination of the plasma arc by removed anode material, a rotating steel cylinder was used as the anode and the arc was anchored onto the cylinder lateral surface. The cathode-anode and cathode-nozzle voltage drops, together with the gas pressure in the plenum chamber were registered for different values of the mass flow rate injected into the plenum chamber. By employing an optical system with a large magnifi cation (<FONT FACE=Symbol>»</FONT> 15 X), the arc radius the nozzle exit was also determined with a digital optical camera. The obtained experimental quantities were used to evaluate several flow properties at the nozzle exit (hot arc plasma and cold gas temperatures, arc and gaz velocities, etc.) by employing a simplifi ed theoretical model for the plasma flow in the nozzle. The obtained results are in reasonable agreement with the data reported in the literature by other authors. Explanations of the origin of the clogging effect and the nozzle voltage are also presented.

Aminophosphonate corrosion inhibitors for steel

The protective properties of aminophosphonic acids and their magnesium and calcium complexes were studied on the example of rotating steel cylinders specimens in soft water. Only two of the seven acids studied, namely 1,1-hydroxycarboxypropane-3-amino-di(methylenephosphonic) and hexamethylenediamine-N,N-tetra(methylenephosphonic) acids, can suppress the corrosion of steel in water completely. As a rule, complexonates are much more effective them the corresponding acids; if the complexing agent is fixed, then the stability constants (K s) of the complexes become the major factor. For phosphonates of Mg2+ and Ca2+, which are usually less stable than the corresponding iron complexonates, the dependence of the protective concentration on K s passes through a maximum; the complexonates of those acids whose own protective properties are weaker are more effective. Imino-N,N-diacetic-N-methylenephosphonic acid can serve as an example. By contrast, the relatively more stable complexonates, for example calcium nitrilotri(methylenephosphonate), are much less effective than the acid itself.

The abrasive wear of steel during rolling-sliding contact with rock counterfaces

In many mining operations ( e.g. excavation, drilling, tunnelling, rock crushing), metallic components are forced against abrasive rocks in a complex motion. This study examines the relative importance of combined rolling and sliding motion in the two-body abrasive wear of a low carbon tempered martensitic steel against rock counterfaces. A novel wear test rig has been used to vary the amount of rolling and sliding motion between a rotating steel cylinder and a counter-rotating sandstone (highly abrasive) or limestone (much less abrasive) disc. Weight loss measurements reveal that the wear rate of the steel increases as the amount of motion against the rock counterface is reduced from pure sliding to about 50% sliding (and about 50% rolling). With further reductions in the amount of sliding motion, the wear rate of the steel is reduced because of the formation of corrugations on the sandstone and limestone rock surfaces. Scanning electron microscopy shows that when the amount of motion is reduced from pure sliding to about 50% sliding, the topographical and subsurface physical properties of the worn steel and rock surfaces are modified. Following large amounts of sliding motion (70–80% sliding), the worn steel surface is heavily deformed by shearing in the sliding direction and many of the minerals in the worn rock counterface are crushed and compacted. Reducing the motion to 50% sliding leads to a reduction in the depth of the plastically sheared layer in the worn steel, and the rock surface shows a considerable reduction in the amount of mineral crushing and compaction, with many of the abrasive grains maintaining some angularity. It is concluded, therefore, that the increasing wear rate of the steel with the amount of rolling motion, until the onset of rock surface corrugations, probably results from the rock counterface retaining a higher proportion of angular abrasive minerals.

Contact Pressures and Stresses in One Theoretically Investigated Case

The investigated case is: Two rotating steel cylinders, infinitely long and with effective radius of curvature of 5 cm, are loaded to Hertzian pressure of approximately 5000 kg/cm2 and are lubricated by an oil. The composite effect of peripheral speed and viscosity (under a given surface temperature) is necessary to build up a lubricating film with a thickness of 1 micron. The solution is approximate and found by the use of elastohydrodynamic theory.

Surface Temperatures in Sliding Contact

A study was made of the surface temperatures generated by friction in a sliding system—a fixed constantan ball riding on a rotating steel cylinder. Using the principle of the Herbert-Gottwein dynamic thermocouple, time-average as well as instantaneous surface temperatures were determined. Some measurements were also made with imbedded thermocouples, and advantages and limitations of both methods are discussed. It was found that the average surface temperature was quite independent of running time and gross wear but increased markedly with increasing speed or load. Under the conditions used in this study (60–250-gm loads and 14–224 cm per second sliding velocities), average surface temperatures ranging from 87 to 239 F were obtained. It is shown that ΔTm = KQn, where ΔTm is the average rise in surface temperature, Q is the total rate of frictional heat supplied, n is approximately equal to 1/2, and K is a proportionality constant. The corresponding maximum surface temperatures reached in these experiments ...

Surface Roughness Effects on Metallic Contact and Friction

A study was made of surface roughness effects on metallic contact and friction in the transition zone between hydrodynamic and boundary lubrication. The system used was one of pure sliding and relatively high contact stress, namely a fixed steel ball riding on a rotating steel cylinder. It was found that very smooth and very rough surfaces gave less metallic contact than surfaces of intermediate roughness; very smooth surfaces also gave less friction. Four different types of antiwear/antifriction additives (including tricresyl phosphate) were studied and although they were found to reduce metallic contact and friction, they had little effect in reducing surface roughness. Rather, the additives merely slowed down the wearing-in process of the base oil. Thus, the “chemical polishing” mechanism advanced for the antiwear behavior of tricresyl phosphate appears to be incorrect. With rough surfaces, the improvement in load-carrying capacity with increasing viscosity was less than that shown previously with smooth surfaces. Also, oils with a large pressure-viscosity coefficient did not show the expected beneficial effect with rougher surfaces.

The Effect of Lubricant Viscosity on Metallic Contact and Friction in a Sliding System

A study was made of the effect of lubricant viscosity on metallic contact and friction in the transition zone between hydrodynamic and boundary lubrication. The system used was one of pure sliding and relatively high contact stress, namely, a fixed steel ball on a rotating steel cylinder. The extent of metallic contact was determined by measuring the electrical resistance between the rubbing surfaces. Increasing the viscosity of Newtonian fluids (mineral oils) over the range from 2 to 1100 centipoises caused a decrease in metallic contact—the effect becoming progressively more pronounced at higher viscosities. The viscosity here was the viscosity at atmospheric pressure and at the test temperature; neither pressure-viscosity nor temperature-viscosity properties appeared to be important factors. On the other hand, non-Newtonian fluids (polymer-thickened oils) gave more metallic contact than their mineral oil counterparts—suggesting that shear-viscosity is important. However, no beneficial effects of viscoe...

Lubrication at point contacts

Measurements have been made of the friction, electrical resistance, and electrical capacity between rotating steel cylinders with their axes mutually at right angles. The lubricant was a plain hydrocarbon mineral oil. Nominally the surfaces come together at a single point and the apparatus is designed to ensure that this condition is maintained even if the cylinders wear. It is shown that hydrodynamic lubrication exists over a wide range of conditions. At loads of a few kilograms it persists even when the speed falls below 1 cm/s and at higher speeds (~ 100 cm/s) it is maintained even when the load becomes large enough to cause bulk plastic flow of hardened steel. Hitherto it has been considered that only boundary lubrication could occur under these extreme conditions. At very light loads classical hydrodynamic theory applies but as the load is increased a departure from classical theory occurs because the viscosity of the oil increases under the applied pressure. At heavier loads the pressures become large enough to cause appreciable elastic deformation of the surfaces and a state of elasto-hydrodynamic lubrication is achieved. Under elasto-hydrodynamic conditions the film thickness can be deduced from the measure­ments of electrical capacity. A simplified theory of elasto-hydrodynamic lubrication at point contacts is developed, and the measured values of film thickness are in fairly good agreement with those derived from the theory. However, the variations of film thick­ness with viscosity, speed and radius of curvature forecast by the theory differ significantly from those obtained experimentally. The values of the film thickness range from 2 x 10-6cm to more than 1 x 10-4cm. The results, over the whole range, conform to a regular pattern and there is no evidence of any disturbing influence of the surface molecular fields, even with the thinnest films.