INTERNATIONAL JOURNAL OF PURE AND APPLIED ... - 185.pdfINTERNATIONAL JOURNAL OF PURE AND APPLIED RESEARCH IN ENGINEERING AND TECHNOLOGY A PATH FOR HORIZING YOUR INNOVATIVE WORK MODIFICATION

Research Article Impact Factor: 2.275 ISSN: 2319-507X Potbhare MS, IJPRET, 2014; Volume 2 (11): 26-33 IJPRET

Available Online at www.ijpret.com

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INTERNATIONAL JOURNAL OF PURE AND APPLIED RESEARCH IN ENGINEERING AND

TECHNOLOGY A PATH FOR HORIZING YOUR INNOVATIVE WORK

MODIFICATION OF WRAPPER ROLL SYSTEM IN HOT STRIP MILL THROUGH

VIBRATION MONITORING AND BEARING SEAL

POTBHARE MS1, DHOMNE S2

1. M-Tech Student (CAD/CAM and Automation), Dr. Babasaheb Ambedkar College of Engg. &

Research Nagpur.

2. Asst. Professor in Dr. Babasaheb Ambedkar College of Engg. & Research Nagpur.

Accepted Date: 12/06/2014; Published Date: 01/07/2014

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Abstract: The aim of this paper is to develop, and evaluate a concept for a new modified bearing use in

wrapper roll system in hot strip mill and its online vibration. With the help of this new modified bearing and online vibration of wrapper roll system the productivity increases and breakdown decreases in hot strip mill. Wrapper roll is one of the most important components in rolling coiler. And it has great relation to the quality of the final product. Based on the programming and optimization experience, a hot strip coiler with new coiling process, which operates with position control and pressure control is introduce. Due to laminar cooling of hot strip in wrapper roller, water increase of the bearing of wrapper roller and due to this roller of spherical roller bearing get rust that leads to vibration and further failure of the system. There are two control methods in wrapper roll control. One is position control which is called CPC (Constant position control) and the other is pressing force control, which is called CPR (constant pressure rolling).The configuration of the system is more compact. It acts slightly, obviously reduces dynamic loads and noise and improves the surface quality of strips. Thus modification in wrapper roller bearing by implementing extra seal in wrapper roller bearing and through vibration monitoring improves the overall performance of wrapper roller system. Keywords: Wrapper Roll System, Online Vibration, Bearing Etc.

Corresponding Author: MR. MANGESH SURESH POTBHARE

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How to Cite This Article:

Potbhare MS, Dhomne S; IJPRET, 2014; Volume 2 (11): 26-33

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INTRODUCTION

With increasing international competition in steel production mainly from developing nations,

it is important for steel plants to keep up to date with new technologies, and continuously

improve on current practices and manufacturing techniques to remain competitive. This paper

looks specifically at improvements to the hot rolling mill downcoilers, which is where the strip is

coiled at the end of the rolling process. Hydraulic and pneumatic technology is combined to

give accurate position control of guide wrappers that aid the initial coiling process.

Down coiler area is the finished product area of the hot strip area and has great influence on

the quality of band steel .Wrapper roll is the most important parts of the whole system. the

high precision of position and force control of wrapper roll control system enhances the quality

of band steel wrapping.

Literature survey

In recent years, attention has focused on decreasing the breakdown in hot strip mill by applying

modification in system. The paper describes the design, implementation and testing of

modified bearing and online vibration of wrapper roll system in hot strip mill. The results from

the trials demonstrate the advantages to be gained from the modified wrapper roll system. In

the present study, the results obtained from the present study can be used to establish a

database for wrapper roll system in hot rolling processes by determining the effect of modified

bearing and online vibration on wrapper roll system.

Problem occur in wrapper roll bearing

Due to laminar cooling of hot strip in wrapper roller, water increase of the bearing of wrapper

roller and due to this roller of spherical roller bearing get rust that leads to vibration and further

failure of the system.

Figure 1.1 Water Etch on spherical roller bearing.



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A CASE STUDY

Ispat Industries, Dolvi, Maharashtra state is one of the well known rolling industry in India. The

major work carried out in this industry is based on the hot rolling.

Hot rolling is a metalworking process that occurs above the recrystallization temperature of the

material. After the grains deform during processing, they recrystallize, which maintains an

equiaxed microstructure and prevents the metal from work hardening. The starting material is

usually large pieces of metal, like semi-finished casting products, such as slabs, blooms, and

billets. If these products came from a continuous casting operation the products are usually fed

directly into the rolling mills at the proper temperature. In smaller operations the material

starts at room temperature and must be heated. This is done in a gas- or oil-fired soaking pit for

larger workpieces and for smaller work pieces induction heating is used. As the material is

worked the temperature must be monitored to make sure it remains above the recrystallization

temperature. To maintain a safety factor a finishing temperature is defined above the

recrystallization temperature; this is usually 50 to 100 °C (90 to 180 °F) above the

recrystallization temperature. If the temperature does drop below this temperature the

material must be re-heated before more hot rolling.

Hot rolled metals generally have little directionality in their mechanical properties and

deformation induced residual stresses. However, in certain instances non-metallic inclusions

will impart some directionality and workpieces less than 20 mm (0.79 in) thick often have some

directional properties. Also, non-uniformed cooling will induce a lot of residual stresses, which

usually occurs in shapes that have a non-uniform cross-section, such as I-beams. While the

finished product is of good quality, the surface is covered in mill scale, which is an oxide that

forms at high-temperatures. It is usually removed via pickling or the smooth clean surface

process, which reveals a smooth surface. Dimensional tolerances are usually 2 to 5% of the

overall dimension.

Hot rolling is used mainly to produce sheet metal or simple cross sections, such as rail tracks.

Other typical uses for hot rolled metal includes truck frames, automotive wheels, pipe and

tubular, water heaters, agriculture equipment, strappings, stampings, compressor shells, truck

frames, railcar components, wheel rims, metal buildings, railroad-hopper cars, doors, shelving,

discs, guard rails, pipe and tubular, automotive clutch plates.



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Conceptual design:

Rolling contact bearings are used in almost every type of rotating machinery whose successful

and reliable operation is very dependent on the type of bearing selected as well as the precision

of all associated components, i.e. shaft, housing, spacers, nuts etc. Bearing engineers

FIG 3.1 Online Vibration Monitoring Concept

Generally use fatigue as the normal failure mode, on the assumption that the bearings are

properly installed, operated and maintained. Today, because of improvements in

manufacturing technology and materials, it is generally the case that bearing fatigue life, which

is related to sub surface stresses, is not the limiting factor and probably accounts for less than

3% of failures in service.

Unfortunately though, many bearings fail prematurely in service because of contamination,

poor lubrication, temperature extremes, poor fitting/fits, unbalance and misalignment. All

these factors lead to an increase in bearing vibration and condition monitoring has been used

for many years to detect degrading bearings before they catastrophically fail. Vibration

monitoring has now become a well accepted part of many planned maintenance regimes and

relies on the well known characteristic vibration signatures which rolling bearings exhibit as the

rolling surfaces degrade. However, in most situations bearing vibration cannot be measured

directly and so the bearing vibration signature is modified by the machine structure, this

situation being further complicated by vibration from other equipment on the machine, i.e.

electric motors, gears, belts, hydraulics, structural resonances etc. This often makes the

interpretation of vibration data difficult other than by a trained specialist and can in some

situations lead to a misdiagnosis, resulting in unnecessary machine downtime and costs.



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Modified Bearing:

FIG 3.2 Modified Bearing with Extra Seal

Sealed bearings differ from shielded or open bearings in that they cannot be relubricated once

the lubrication breaks down or leaks out. Although this results in a shorter overall life span than

that of properly maintained shielded or open bearings, sealed bearings, when used properly,

still have a number of advantages over unsealed bearings.

Unsealed bearings must be lubricated at regular intervals to prevent failure, whereas sealed

bearings are lubricated by the manufacturer and never need to be lubricated again. This saves

labor, no matter what the application, but it is particularly valuable when the bearing is located

in an inaccessible part of the machine. Unsealed bearings in hard-to-reach places often require

partial disassembly of surrounding components to perform maintenance on the bearing. The

same route that allows the addition of lubricant to unsealed bearings also allows entry of

contaminants, which increase wear and tear and shorten the life of the part. Sealed bearings do

not offer an entrance path for contaminants, as long as the seal is intact; the same covering

that keeps the lubricant inside keeps out everything else. The reverse is also true; failure of the

seal soon results in the failure of the bearing.

Sealed bearings eliminate the potential for accidental over-lubrication. Unsealed bearings fail

more frequently from over-greasing than from under-greasing. This requires the proper use of

sealed bearings; never install grease fitting on a sealed bearing or attempt to force grease into

it. Clearly mark machinery with sealed bearings to ensure that any technician who works on it

knows not to try to lubricate them. Sealed bearings can be of either the contact or noncontact

type. The seal in a contact bearing touches the inner race, or the inner track on which the ball

bearings spin. This keeps out moisture more effectively but results in quicker wear and higher

operating temperatures. Noncontact bearings have a seal that does not touch the inner race.



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They run cooler and with less friction but are not as effective at excluding moisture from the

bearing.

TEST RESULT AND DISCUSSION

FIG 4.1Acceleration Spectrum after Bearing Replacement

FIG 4.2 Velocity Spectrums after Bearing Replacement

FIG 4.3 Overall Trends after Bearing Replacement



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AMS ™Suite: Machinery Health™ Manager v5.4

The AMS Machinery Manager v5.4 release is the result of user input collected during plant visits

and documented by customer support and marketing teams. This release includes

enhancements that will simplify the work of every experience level.

The major AMS Machinery Manager v5.4 enhancements focus on data visibility and ease of use.

For example, spectral and waveform data from the CSI 9420 Wireless Vibration Transmitter can

be viewed in the AMS Machinery Manager application. And machinery health programs are

strengthened through the 3-step integration of AMS Machinery Manager with Emerson’s

DeltaV and Ovation process automation systems.

CSI portable technology users will find increased software functionality and reduced time spent

performing routine procedures, especially in the vibration and infrared thermography modules.

New database reporting capabilities allow summarized reporting of analysis parameter, fault

frequency, and alarm limit sets by machine and/or analysis group. A new Overall Vibration

Index report in the Export application identifies all monitored assets in the plant that have

exceeded their assigned vibration threshold limits.

As we have seen in acceleration spectrum, velocity spectrum and in overall trend the vibration

in wrapper roller bearing is decreases. This leads to less breakdowns and increase in

productivity.

CONCLUSION

This research paper presents the modification of wrapper roll system in hot strip mill through

bearing seal and online vibration monitoring which is useful in hot rolling process. This modified

system gives the vibration report online which is useful for maintenance of the hot rolling

process.

In this way this modified system is successfully implemented for hot rolling process. Thus this

expert system is very helpful in the hot rolling industries.

REFERENCES

1. Harris T A, Rolling Bearing Analysis (4th Ed), Wiley, New York, 2001.

2. Lacey S J, Vibration monitoring of the internal centre less grinding process, Part 1:

mathematical models. Proc Instn Mech Engrs. Vol 24. 1990.



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3. Lacey S J, Vibration monitoring of the internal centre less grinding process, Part 2:

experimental results. Proc Instn Mech Engrs. Vol 24. 1990.

4. Wardle F P and Lacey S J, Vibration Research in RHP. Acoustics Bulletin.

5. Bearing Repair Provides Valuable Alternative to Bearing Replacement for Heavy Industries”

K. Flowers, June, p 85.

6. Improving the Quality of Steel Slabs and Billets with Additional Electric Heating Elements, K.

M. Tiitto, J. M. Pyykkonen and P. T. Mantyla, Sept., p 52.

7. Modernization and Upgrading of Existing Plants A Decisive Factor in the Field of Hot Strip

Mills, A. Angerbauer, B. Haring and R. Burger, May, p 267.

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INTERNATIONAL JOURNAL OF PURE AND APPLIED ... - 185.pdfINTERNATIONAL JOURNAL OF PURE AND APPLIED RESEARCH IN ENGINEERING AND TECHNOLOGY A PATH FOR HORIZING YOUR INNOVATIVE WORK MODIFICATION