Plant Upgradation at Barak Valley Cements

Barak Valley Cements recently did plant upgradation to improve its efficiency. The company did design fabrication and installation of Clinker Cooler and also increased kiln speed. The company was able to boost production by 33 per cent. Here is a case study on the plant upgradation.

Barak Valley Cements, incorporated in the year 1999, is engaged in the business of manufacturing of cement of different grades and is marketing its product under the brand name "Valley Strong Cement". The company started its commercial production in April 2001. Initially the company started its commercial production at the capacity of the plant at 300 TPD , subsequently company undertook various expansion and modernization plans from time to time which increased the installed capacity to 600 TPD of clinker and 750 TPD of cement. The technology that is used in manufacturing our product is Dry Process Rotary Kiln Technology with 4 stage Suspension Pre Heater technology.

The company is located in Assam and all the operations of the company are concentrated in the North Eastern region. The manufacturing unit of the company is at Jhoom Basti, Devendranagar, Badarpurghat, District Karimganj, Assam. The sales are also concentrated in the North Eastern region of India. The product portfolio includes both Ordinary Portland Cement (OPC) and Portland Pozzolana Cement (PPC). Barak Valley Cements is ISO 9001: 2008 certified company and their products confirm to BIS (Bureau of Indian Standards) specifications.

The BVCL plant is the largest cement plant in the State of Assam. Deficit cement market in North East Region (NER) has benefited the company, since cement demand has been growing at a faster pace in NER than rest of the country due to material gap between demand and supply. The plant is close to north-eastern states such as Mizoram, Tripura, and Southern part of Meghalaya, which are company?s target markets. Barak Valley is at the foot land of all the three states and Badarpur Ghat is the junction point. Continuing withs its trend in improving production efficiency the plant was recently upgraded. Here is a snapshot of few developments that took place.

Design Fabrication and Installation of Clinker Cooler Initially due to space constraint a Rotary Cooler was installed at 900 of kiln line at Barak Valley Cement. This cooler was not effecting so far cooling efficiency was concerned. The conventional cooler such as grate cooler, Ikon, Pendulum etc., were not possible. Conventional cooler requires more depth owing to spillage chambers and then conveying of spillage clinker. With the available space, a Cooler has been designed in house, fabricated & erected which is completely hydraulically operated. Each chamber consists of Zet Plates Fixed, over which pushers run to and fro pushing the hot clinker forward. Cold Air Passing through Zet Plate not allowing Spillage of clinker as found in Conventional Cooler due to having perforated plates.

Special feature over Conventional Cooler

• No Spillage Chamber.
• No loss in under Grate Pressure, utilizing full quantity of Air.
• No wear & tear in Zet Plates because it is not under abrasion life 5-6 years.
• No drop in pressure.
• Availability of high & consistant Secondary Crusher.
• Clinker Grindibility increased due to better air quenching.
• Clinker temperatures at discharge remain to be below 800 C – 900.
• Clinker is transported through rubber belt conveyor.

Construction in Brief
This cooler is having 4 chambers. A Chamber 2.2 meter wide x 3.5 meter long having nos. of Zet Plates duly fabricated by stainless steel plates as per the enclosed drg. These plates are fixed over the chamber plateform.

A pair of channel is fixed over the Zet Plates and a pair of channel reversed in position moves to and from through a box connected with hydraulic jack one row of fixed pusher and one row of moving pushers are welded. The driving box is connected with a jack which moves to and fro and the stroke of clinker depth is adjusted through P.L.C. When clinker falls from kiln, it is pushed by moving pusher over the fixed triangular pusher so that clinker does not come back. This way clinker gets forwarded motion and falls to next chamber. Finally cooled clinker gets discharged over rubber belt conveyor and then to clinker yard. A drawing is attached for study.

Kiln Twin Drive Problem

• Speed of Kiln limited to 1100 rpm of motor.
• Less Production.
• Run out at Drive causing tripping of VFD due to excessive current hunting. System Modified
• Second Auxiliary Motor of 110 kw added on other side.
• Installation 110 kw V.F.D on secondary drive with different ratio of gear box & different kw of main drive.
• PLC system for synchronization and load sharing with 220 kw/80:1 gear box with 110 kw/66:1 gear box.
• Previous system had a 220 KW drive motor. At present the modified system is running smoothly with configuration shown in above table.

Achievement
The company was able to increase the kiln speed. As a result the production capacity increased by 33 per cent. The twin drive system also solved the issue of current hunting & tripping. Overall, the modifications helped in smooth kiln operation and and gave stability to current flow due to load sharing.