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International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 1, January 2018, pp. 378–387, Article ID: IJMET_09_01_041 Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=9&IType=1 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication Scopus Indexed

DESIGN AND ANALYSIS OF MODIFIED IDLER

IN DRAG CHAIN CONVEYOR

B.Radha Krishnan, M.Ramesh, R.Giridharan and R.Sanjeevi

Assistant Professor, Department of Mechanical Engineering, K.Ramakrishnan College of Engineering

Dr.D.Srinivasan

Principal, K.Ramakrishnan College of Engineering

ABSTRACT

The 20th century has been a period of rapid developments in manufacturing

technology. Mass production has become the dominant manufacturing activity in the

world. Mass production means single-product, large-lot-size production. The major

problems in Mass production is a high quantity of products transfer from one place to

another place Several effective methodologies have been developed for solving Mass

production problems such as, conveyors, cranes, pumping System, trucks, and special

purpose vehicles.

The focus of this paper is redesigning the chain type conveyor and eliminates the

errors. This paper work is mainly concentrated on modify the existing idler in the

chain type conveyor and eliminate the failure of idlers due to various errors. Due to

introducing anti frictional bearing by modified existing system of frictional type Ni-

Hard bearing bush, the following benefits are derived; increased life span of idler

consequent to that then consumption of idlers will get reduced drastically. Breakdown

of machining have been avoided due to failure of idlers. Maintenance is reduced, on

account of consumption of idlers and its spares. Lesser power is needed due to

reduced load to the conveyor drive motor because of introducing anti frictional

bearing

Keywords: Composite Materials, Fabrication Process, Testing Process, Results, Discussion

Cite this Article: B.Radha Krishnan, M.Ramesh, R.Giridharan, R.Sanjeevi and Dr.D.Srinivasan, Design and Analysis of Modified Idler in Drag Chain Conveyor, International Journal of Mechanical Engineering and Technology 9(1), 2018. pp. 378-387. http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=9&IType=1

Design and Analysis of Modified Idler in Drag Chain Conveyor


1. INTRODUCTION AND CEMENT MANUFACTURING PROCESS

The basic raw material for cement manufacture is limestone. It is being mined in lime stone mines and transported to primary crusher-cum-picking plant where primary crushing of limestone takes place. The crushed limestone is then cleaned manually in the picking belt and after removing the unwanted black rejects, the cleaned limestone (78% CaCo3) is then sent to secondary crusher for further crushing. The cleaned limestone of required quality and size is then brought to cement plant by tipper. These materials are conveyed to limestone hopper through belt conveyor and then fed in to slurry mill having a size of 3 M diameter and 12.7 M length through table feeder where it is ground by adding 33%of water approximately .these mills have three compartments filled with grinding media of desired quantity and size, which grinds the crushed limestone with water slurry.

The slurry pumps pump then slurry to storage silos. This slurry is taken to the mixer basin where it is stirred well by compressed air and corrected to the desire quality. It is then sent to kiln section and fed into rotary kiln at one end of it subject to chemical reaction at a temperature of 13000 to 14000c by burning fine coal at the other end so as to form nodules called clinker. The dust laden hot gas is drawn into electro static precipitator where in the dust particles are separated and the cleaned hot gas is vented out through exhaust chimney. The separated dust particles are recycled back into the kiln through conveyor and bucket elevator and get converted into clinker.

The hot clinker coming out from the kiln is fed into clinker cooler and cooler and get cooled by forcing atmospheric air into three compartments cement mills having a size of 3.75m diameter and 12.75m length along with 5% gypsum and the ground product coming out of the mill is called ordinary Portland cement (OPC). When the cement is ground with a proportion of 75% clinker, 5% gypsum and 20% fly ash. It is called Portland pozzolana cement (PPC). The cement is then conveyed to storage silos and packed into 50kgs of PP/paper bags and dispatched through tucks.

PLANT AND MACHINERY CAPACITY

Primary Crusher

Type: Double toggle jaw (DTJ) crusher

Capacity: 325 TPH

Feed size: 1.5×1.2mm

Drive: (-) 50mm

End product size: 190Kw/1000RPM, 3.3Kv HT motor

No of unit: ONE

Secondary Crusher

Type: Single rotor impactor

Capacity: 250 TPH , Feed size: (-) 250mm

End product size: 190Kw/1000RPM, 3.3Kv HT motor

No of unit: ONE

E.O.T. Crane Lifting capacity: 10 Tones

Span: 30 meters Height of lift: 13 meters Drive: Hoist & crab – 90HP/750 RPM

Long travel – 60 HP/970 RPM

NO. Of units: TWO

Raw mill

Type: Ball mill

Size: 3m Ø × 12.7 m length in 2 compartments

Capacity: 50 TPH

Feed Size: (-) 250mm

Drive: 2010 HP/1000 RPM 11Kv HT motor

No of units: TWO

Kiln

Type: Rotary kiln (wet process)

Size: 3.75 m Ø × 3.4 m × 3.75 m × 135 m long

Capacity: 630 TPH

Kiln slope: 2˚ (3.5%)

Drive: 220 HP DC/313 RPM

No of units: TWO

B.Radha Krishnan, M.Ramesh, R.Giridharan, R.Sanjeevi and Dr.D.Srinivasan


2. PARTS OF DRAG CHAIN CONVEYOR

The parts of Drag chain conveyor unit consists of a shaft, hollow pipe, hollow cylinder, idler, bushes, disk, bearings, bearing end block.

A. Drag Chain

Drag chain is made up of stainless steel. It is used to carry the clinker material from one place to another. The bottom of the chain dragging toe clinker from tail end to head end (tension side) and top of the chain is called return side (loose side). This loose side of 64 meter length supported by 18 idlers with equal space.

B. Shaft

A shaft is a rotating machine element which is used to transmit power from one place to another place. the power is delivered to the shaft by some tangential force and the resultant torque (or twisting moment)set up within the shaft permits the power to be transferred to various machines linked up to the shaft. When the process time the shaft only carried the all loads of the drag chain conveyor. EN 24 shaft has used for in this idler.

C. Electrical Motor

The electrical motor is mainly used to operate the drag chain conveyor. The capacity of this electrical motor is 10HP. The electrical motor shaft has directly connected with the idler shaft.

D. Idler

Idler is a rotating device, it is used to carried the weight and load of the drag chain conveyor and clinker. The drag chain has flow over this idler.

A. Bearing

A bearing is a machine element which supports another moving machine element (known as journal). It permits a relative motion between the contact surfaces of the members, while carrying the load. The two ends of the shaft has supported by the bearing.

B. M.S Pipe

The pipe has made up of mild steel. This MS Pipe used to weight reducing purpose of the idler and also it has low cost consumption. The length of this pipe is 1080mm.

C. Hollow Cylinder

The main purpose of the hollow cylinder is weight and cost reducing purpose. It is made up of manganese and cast iron. The diameter of this cylinder is 203mm and the length of this cylinder is 810mm.

D. Disk

Disk is a one of the circular object; it is used to weight reducing purpose only. It has attached with the hollow cylinder. The width of this disk is 10mm.

E. Bush

The bush has made up of NI-Hardening. It is used to support the shaft for rotating motion.



3. EXISTING IDLER

In existing idler consisting the numbers of various parts are to be used such that Manganese steel block for idler, EN-24shaft, Ball bearings no: 6209 and Ni-Hardening bush.

Figure 1 Existing Idler

A. Manganese Steel Block for Idler

In manganese steel block is produce the idler to transmit the chain. The manganese steel block is to formation of idler by using casting process. Then the casting process, the steel blocks are to be machined in the formations of idler. This is hardened compared to the other blocks of idler.

The manganese steel idler is the various properties are

Density = 7.21g.m - 3

Melting point = 12460c

Thermal expansion = 250c

Bulk modulus = 120Gpa

Moh’s hardness = 6.0

The manganese steel block is used to production of idler; it is high strength and hardness. So it should be withstand the load of chain. The idler weight is (41kg) for one number. In this idler is to be used in drag chain conveyor, the load (344.8kg) of acting on the idler on the surface of the manganese steel block idler. The idler go more unwanted weight to be wearing the chain.

Figure 2 Manganese steel block for idler



B. En-24 Shaft

European standard steel grade names fall into two categories:

1. Steel specified by purpose of use and mechanical properties.

2. Steel specified by chemical composition.

The inclusion of a letter 'G' before the code indicates the steel is specified in the form of a casting. The materials of EN-24 are following items.

Table 1 EN – 24 Materials

C. Si. Mn Ni. Cr. Mo.

0.40% 0.30% 0.60% 1.50% 1.20% 0.25%

The materials of EN-24 are having the various properties are high quality, high tensile and Alloy steel. Usually supplied readily machine able in ‘T’ condition. It combines high tensile strength, shock resistance, good ductility and resistance to wear. EN24 is available from stock in round bar, flat bar and plate.

Figure 3 EN 24 Shafts

C. EN-24 Properties

• Heat uniformly to 823/850oC until heated through. Quench in oil.

• Heat uniformly and thoroughly at the selected tempering temperature, up to 660oC and hold at heat for two hours per inch of total thickness. Tempering between 250-375oC in not recommended as this can seriously reduce the steels impact value.

• Heat slowly to 650-670 C, soak well before cooling the EN24 tool in a furnace or in air.

Table 2 Mechanical Properties

Heat

Treatmen

t

Tensile Strength

Rm N/mm²

Yield

Stress Re

N/mm²

Impact

Izod J

Impact

charpy J

Proof

Stress

rp0.2

Hardness HB Size mm

T 850/1000 654 40 35 635 248/302 >150≤250

T 850/1000 680 54 50 665 248/302 >63≤250

U 925/1075 755 47 54 740 269/331 >29≤100

V 1000/1150 850 47 42 835 293/352 >13≤63

W 1075/1225 940 40 35 925 311/375 >6≤29

X 1150/1300 1020 34 28 1005 345/401 >6≤29

Z 1550 1235 10 9 1125 444 >6≤29



The EN-24 shaft is coupled to manganese steel block idler with the help of key ways. This shaft is to be rotated with the help of bearings to avoid the friction occurs between the shaft and contact surface.

The EN-24 shaft is to be machined to the formations of step turning to withstand the load. The load is fully acting on the EN-24 shaft and contact surface of bearings. The EN-24 shaft and manganese idler is to be joined by using the welding. It is due to stress formed in the shaft during welding.

D. Ball Bearing 6209

A bearing is a machine element to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as well as by the directions of applied loads they can handle.

E. Ni-Hardening Bush

Nickel is used as a binder in the cemented tungsten carbide or hard metal industry and used in proportions of six to 12% by weight. Nickel can make the tungsten carbide magnetic and adds corrosion-resistant properties to the cemented tungsten carbide parts, although the hardness is lower than those of parts made with cobalt binder. The Ni-Hardening bush is fixed between idler and EN-24 shaft. This bush is used to contact the shaft and idler but the wear and friction will occurs on the bearings.

F. Problem Analysis for the Existing Idler

• The idler go more unwanted weight to be wearing the chain.

• It is due to stress formed in the shaft during welding (Hard facing).

• The idlers not rotating freely due to more line of contact of the shaft with bearing bush causing excess stress due to surface contact lead to arrest the free rotating of shaft.

4. MODIFIED IDLER

Idler is a rotating device, it is used to carried the weight and load of the drag chain conveyor and clinker. The drag chain has flow over this idler. Modification of idler is to improve the durability of over loading, capable to work without one year period of maintenance. Considerable changes are takes place and weight of the modified

Idler mostly used

Figure 4 Modified Idler

A. M.S Hollow Pipe & Shaft

The pipe has made up of mild steel. This MS Pipe used to weight reducing purpose of the idler and also it has low cost consumption. The length of this pipe is 1080mm.MS pipe is known for high torsion, rigidity and compressive strength. The smooth and uniform profile of



hollow sections minimizes corrosion and facilitates easy on site fabrication. Hollow sections are used in industrial sheds, bridges, commercial and residential construction, and many more.

A shaft is a rotating machine element which is used to transmit power from one place to another place. the power is delivered to the shaft by some tangential force and the resultant torque (or twisting moment)set up within the shaft permits the power to be transferred to various machines linked up to the shaft. When the process time the shaft only carried the all loads of the drag chain conveyor. EN 24 shaft has used for in this idler.

Figure 5 M.S Hollow Pipe Figure 6 Shaft

B. Bearing and Bearing End

A bearing is a machine element which supports another moving machine element (known as journal). It permits a relative motion between the contact surfaces of the members, while carrying the load. The two ends of the shaft has supported by the bearing. The most sophisticated bearings, for the most demanding applications, are very expensive, highly precise devices, whose manufacture involves some of the highest technology known to human kind.

Bearing end is used to support the veering at the end of the shaft. It can be used for lock the bearing in position and with stands all stresses developed in shaft.

Figure 7 Bearing Figure 8 Bearing Ends

C. Hollow Cylinder and Bushes


Figure 9 Hollow Cylinder Figure 10 Bushes



D. Support Cylinder & Assembled View of Modified Idler


Figure 11 Support Cylinder Figure 12 Assembled Modified Idler

5. RESULT ANALYSIS

A. Results of Existing Idler

The following problems are identified in the existing idler.

• The idler go more unwanted weight to be wearing the chain.

• It is due to stress formed in the shaft during welding (Hard facing).

• The idlers not rotating freely due to more line of contact of the shaft with bearing bush causing excess stress due to surface contact lead to arrest the free rotating of shaft.

Figure 13 Stress Analysis of Existing Idler

Total cost of Existing idler = 32000 Rs each

Total weight of Idler and shaft = 136.64Kg

Stress = load/Area

= (213.4×9.81)/{π/4×652}

Stress (σ) =0.213 X 10-3 N/mm2

Deflection (D) = PL/AE = (213.4×9.81×155)/{π/4×652×2×105} =0.480 X 10-3 mm

Maximum stress developed= 0.213 X 10-3 N/mm2

Maximum deflection = 0.480 X 10-3 mm



B. Results of Modified Idler

Due to introducing anti frictional bearing by modified existing system of frictional type Ni-Hard bearing bush, the following benefits are derived. Increased life span of idler consequent to that then consumption of idlers will get reduced drastically.

Figure 14 Stress Analysis of Modified Idler

Total cost of Existing idler = 4910 Rs each

Total weight acting on the shaft=379.135 Kg

Stress=load/Area = (189.57×9.81)/{π/4× (41.52)}

Stress (σ) = 0.159 X 10-3 N/mm2

Deflection (D) = Pl/AE= (189.57×9.81×200)/ {π/4×(41.52)×2e5}

D=0.208 X 10-3 mm

Maximum stress developed= 0.159 X 10-3 N/mm2

Maximum deflection= 0.208 X 10-3 mm

Maintenance is reduced, on account of consumption of idlers and its spares lesser power consumption due to reduced load to the conveyor drive motor because of introducing anti frictional bearing.

6. CONCLUSION

Our paper, Design and Analysis of Modified Idler in drag Chain Conveyor is designed and implemented using the latest trends. The Design and Analysis of Modified Idler in drag Chain Conveyor can be implemented in Tamilnadu Cements Corporation in Alangulam Plant where the high productivity is required. It reduces the errors that occurred in Maintenance, on account of consumption of idlers and its spares lesser power consumption due to reduced load to the conveyor drive motor because of introducing anti frictional bearing.

On completing this paper we have gained immense knowledge on the mechanical subject by doing the fabrication ourselves. Our knowledge on the selection of materials, fabrication and machining for the right application has greatly improved. In all doing this paper has enhanced our overall technical knowledge in all the aspects of industrial manufacturing. It has thoroughly tested our knowledge and has successfully implemented our study experience.

Our knowledge and experience in working with the paper has immensely improved. We have also experienced real team-spirit and mutual co-operation by completing this paper successfully.



REFERENCE

[1] F.L.D. Cloete and P. Kirsten, Drag chain conveyor bv.sed on standard engineering components, CSIR Report CENG 118, April 1976

[2] Arnold P.C. and Hill G.L. Predicting the discharge trajectories from belt conveyors. 1EAust. 3rd International Conference on Bulk Materials Storage Handling and Transportation, Newcastle, NSW, Australia, June 1989

[3] Arnold P.C. and Hill G.L. Feeding coal to and from belt conveyors, lEAust. 1990 International Coal Engineering Conference, Sydney, Australia, June 1990

[4] Whittaker P. Design concepts for the layout of troughed belt conveyor transfer stations. IEAust. 1st International Conference on Bulk Materials Storage Handling and Transportation, Newcastle, NSW, Australia, 1983

[5] Korzen Z. Mechanics of belt conveyor discharge process as affected by air drag. Bulk Solids Handling 1988. 9, No. 3, 289-297

[6] Arnold P.C. and Hill G.L. Design of conveyor chutes with special attention to blockage wear and conveyor direction change. NERDDP Project 1188 Report, April 1991

[7] Park, Y. B. (1996). ICMESE: intelligent consultant system for material handling equipment selection and evaluation. Journal Manufacturing System, 15(5), 325–336.

[8] Swaminathan, S. R., Matson, J. O., & Mellichamp, J. M. (1992). EXCITE: expert consultant for in-plant transportation equipment. International Journal of Production Research, 30(8), 1969–1983.

[9] Fisher, E. L., Farber, J. B., & Kay, M. G. (1988). MATHES: an expert system for material handling equipment selection. Engineering Costs and Production Economics, 14, 297-310.

[10] Honng, W. L (1990). MATHES II: an expert system for material handling equipment selection, unpublished thesis, Industrial Engineering Department, NCSU.

[11] Roma Rani, Pankaj Rai, Jyoti Athiya, Design and Analysis of Second Generation Current Conveyor Based Low Power Operational Trans conductance Amplifier, International Journal of Electrical Engineering & Technology (IJEET), Volume 6, Issue 4, April (2015), pp. 09-15

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