Upgradation of 6Hi Reduction Mill

Transcription

1 Upgradation of 6Hi Reduction Mill CMI FPE LTD., CMI Industry Category: Technology

2 6 Hi Reduction Mill 12/2/2018 2

3 1. Brief presentation of the project Following upgradation has been undertaken to enhance the 6Hi Reduction Mill. Roll change with strip inside the mill Useful for tandem and twin stand mills Roller type pressure board Increases available time for production and reduce contamination of the coolant Air oil arrangement for work roll and intermediate roll Bearings run cooler and cleaner Cobble guard upgradation Compact design and adjustment as per roll diameter Online Intermediate Roll (IMR) shifting Ease of operation Over all aesthetics of the Mill

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5 2. The project owners and its timing Team members Sandip Dhuri Krishna Pimpale Rajesh Nalawde Shrirang Kulkarni Mentor: Sanjay Navare Sponsor: Raman Madhok Timeline: Aug 2017 Nov 2018 Bhaskar Karade

6 What has been achieved / put in place Rails were added for independent removal of work roll and IMR which helped in removing the rolls with strip inside the mill. Rolls were added in place of wooden/ UHM plastic boards for achieving back tension in the first pass so as to reduce the maintenance time. Traditionally grease lubricated arrangement was changed to air oil arrangement to keep the bearing clean and increase in life. Cobble guard assembly was too bulky with lot of piping. The new design is more compact and piping arrangement is made better. The necessary value additions were incorporated to ease the adjustment of IMR online for correction of shape. Aesthetics have been improved for easy identification and better branding

7 4. Contribution to a current challenge To be more competitive and to have an edgeover in the market for selling of our mill. Looking ahead for designing tandem mills. Bearing life is improved by 20%. Lower maintenance time. Value addition to our existing product. Increase in machine availability time. Increase in production. Reduce contamination of the coolant. Good selling USP for our mill. Aesthetics improved for easy identification and better branding

8 5. Collaborative approach Our internal team visited a few customers to understand the need for change and made a study of various arrangements. Followed by brain storming within the engineering team along with feedback from the erection and commissioning team. Various literature / photos of competitors were referred on these subjects to get an idea on the additional changes that are needed in our product to enhance its utility to the customer. Many ideas in each category were presented out of which the ones highlighted in BLUE are the ones that we have implemented. Cobble Guard Pressure Board Roll Change Lubrication arrangement for Work Roll/ IMR Rotary movement Multiple small roller Separate rails for work roll/ IMR Single Pneumatic cylinder existing Double hydraulic cylinder with inclined movement Single hydraulic cylinder with short stroke Multiple long rollers Present without strip inside Air Mist UHM boards Wooden board old design Grease lubrication Air Oil

9 COBBLE GUARD ASSEMBLY NEW OLD 12/2/2018 9

10 COBBLE GUARD OLD DESIGN Large cobble guard Frame with coolant & air spray header. The coolant supply headers are connected with Spray headers with number of long flexible hoses. NEW DESIGN Having less weight & coolant supply lines. The quantity & length of hoses reduced. Two pneumatic cylinder are given for in-out movement of Cobble Guard & screw jactuator arrangement for cobble position adjustment with respect to Work roll diameters. In out movement of Cobble Guard will be done by two hydraulic cylinder having Position Transducer for easy adjustment of cobble guard position according to changes in Work roll diameter. Due to location of Supply headers & hose pipe there are possibility of obstruction in fumes flow toward hood. Which causes the condensation of fumes & coolant droplet on finish strip. Due to new arrangement of coolant supply header with piping & Cobble guard position adjustment, The fumes & coolant carry over problem will be reduced. 12/2/

11 ROLLER TYPE PRESSURE BOARD Pad Type Pressure Board In pad type pressure board, pad are required to change during strip width changed from max to min or vice versa. Increase in maintenance cost & loss production time. Roller Type Pressure Board No need to changed roll for max to min strip width, increase production time Pad Type Pressure Board Due to wear & tear of pad, it needs to be replaced frequently. Harden & Tempered roll, less wear Debris from the pressure pad either lodge themselves in the coolant nozzle (thereby affecting shape) or give incessant marks on the strip which are visible after galvanizing and /or color coating. No Debris Roller Type Pressure Board 12/2/

12 ROLL CHANGE WITH STRIP INSIDED THE MILL IMR and WR chocks modified with wheels to ease removal. Work Roll or IMR Roll can be changed Independently as well as together. Auto Roll change with minimum Roll change time is 6 min. Separate rails provided for top WR. 3D Model Actual Site photo 12/2/

13 ROLL CHANGE OLD DESIGN While work roll change, we required to remove strip from mill stand & also the top work roll removed on bottom work roll by providing spacer pin between them. So because of this the work roll change cycle time is 25 minutes. NEW DESIGN The work rolls can removed even the strip will present in mill stand & also for top work roll change separate rails are provided. Now with this design work roll change will be done with in 5-6 minutes. While finish pass, if we want to change work roll due to roll surface texture issue, then whole strip required to be removed from mill stand which causes the yield loss. This design cannot be used for Tandem Mills. No need to remove the strip hence saving the yield loss. Suitable for Twin Stand mills and our future product - Tandem Mills 12/2/

14 AIR OIL LUBRICATION ARRANGEMENT IN WR & IMR Auto Coupled / Decoupled connection Drag Chain Prevents Entanglement / Damage Of Hoses During IMR Shifting Maintenances free Bearing runs clean Operator Side Arrangement Drive Side Arrangement 12/2/

15 AIR OIL BEARING LUBRICATION FOR WR, IMR Advantages of Air Oil Lubrication Over Grease & Oil Mist Low Lubricant Consumption - Air Oil consumption = 4 ltrs per day Drop in Bearing Temperature compared to Grease & Oil Mist No Air Pollution With positive pressure no contamination thus enhanced bearing life No grease, no disposal and maintenance cost during it s inspection Easy Maintenance Lubricant Air Oil Oil Mist Grease Strip Speed Higher Speed Higher speed but Hazardous Medium speed 12/2/

16 AIR OIL BEARING LUBRICATION GREASE LUBRICATION Grease contaminates the Coolant oil. Due to coolant oil contamination in grease & at higher speed, there is possibility to increase bearing temperature. Due to contamination the grease consumption is more. Bearing life is comparatively less. Maintenance time taken for grease removal. AIR OIL LUBRICATION Coolant oil contamination is less. Due continuous circulation of air-oil, chances of rising bearing temperature are less. Low lubrication consumption & Cleanliness With positive pressure no contamination, bearing life is more. Easy maintenance in less time. 12/2/

17 ONLINE IMR SHIFTING Position transducers provided in IMR Shifting cylinders with servo valves. Inline adjustment on load to correct edge drop of the strip. Forces were calculated and optimum adjustment speed ranging from 1mm to 2 mm/sec was estimated. 12/2/

18 ONLINE IMR SHIFTING OFFLINE IMR SHIFTING INLINE IMR SHIFTING In case of IMR shifting, the mill was to be stopped, roll gap opened and then the roll positions were adjusted. It can be done in a running mill. Due to above loss of time, yield was affected. No yield loss. Faster shape correction 12/2/

19 6. Cost / impact ratio EQUIPMENT OLD DESIGN UPGRADED DESIGN Cobble Guard (Weight) 2750 Kg 1300 Kg Roller Type Pressure Board (frequency of Pad replacement) Work roll change (Cycle time) Air Oil lubrication (Bearing Temperature) Inline IMR Shifting After certain time pad wear & required replacement regularly. 2.1% per year lost for replacement plus the material cost. 25 minutes (incl. removal of strip from the mill) Higher temperature Cannot shift IMR in running for shape correction hence yield loss is more. IMR shifting cycle time is 20 minutes. Harden & temper roll having less wear so frequency of replacement is less. Production hours saved equivalent increase of production by 1.5 % 6 minutes 50 C - 60 C (less contamination of coolant) IMR can shift in running for shape correction, so yield loss is very less. Inline shifting

20 7. Time-scale for impacting the business The upgradation is being undertaken for implementation on live projects. August 2017 December 2017 The idea for upgradation of Mills was initiated September 2018 November 2018 Drawings issued to projects with Santander, Spain and PHP, Bangladesh August 2019 The mills with the upgradation will be commissioned for both projects

21 8. Long-lasting nature of the project It is response through time due to the interaction with customers and their growing needs. The costumer always demanded for new feature in our product. The solutions provided will be used on all mills and will be promoted as the standard features. The solutions are improvement to the existing product

22 9. Means deployed for the promotion of the project A presentation to the Sales team and Spares & Services team was made to highlight the value additions made for a better and improvised Mill. The upgradation proposed are being promoted during visits to all customer during presales. Spares & Services team is in talks with existing clients for the upgradation of their existing/old mills

23 10. Deployment of essential skills Increased product yield Client oriented Better Product Machine utilization Cost saving

24 11. Contribution of the project to the reputation, of CMI and its operations Value-added product Better USP for marketing the Mills and processing lines Easy to approach high-end customer Better performance guarantees Increased Safety standards