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Efficient Fibre Processing by Recovery through Rotary Screen-2a

Description

Removal of contaminants and recovery of fibres and fines from process water including cylinder mould filtrate is necessary for cleaning process water. Use of Special Rotary Screen helps to maximise the process of recycling as well as recovery of fibre. This case study describes, how the above could be effectively achieved by using a Special Rotary Screen.

Implementing Industry

Daman Ganga Paper Mills is a medium sized company engaged in recycled packaging products. Company produce a range of recycled products such as Paper, Core-Board, Cores & Tubes, Fibre-Drums, Partition Boards, Insulation Boards, Acoustic Boards, etc. The company started its operation in the year 1982, with present production capacity of Kraft Board 60 Tons per day, with annual turnover of 50 Crores.

Implemented technology / technique

BEFORE:

  • Filtrate from Hydro Pulper (intermittent) and High Density Cleaner (intermittent) with filtrate from Cylinder Mould combined with Paper machine chest (continuous) are mixed in mixing box where floating impurity removal was practiced through manual operation, the filtrate of which is sent to ETP after removal of floating impurities. Thus resulting in low removal efficiency of fibre and fines.

  • The practice increased SS (suspended solids) and TDS (Total Dissolved Solids) in filtrate water being sent to ETP from Mixing Box. This increased solid waste from primary clarifier in form of sludge and was required to be disposed to TSDF site.

  • Since the filtration/scr is not done and the streams are mixed, the valuable fibre leads to the sludge with fines & contaminants through ETP. 

AFTER:

  • The stream lines for Hydro Pulper (intermittent) and High Density Cleaner (intermittent) made first loop and segregated from the stream from Cylinder Mould combined with Paper machine chest, which made the second loop. 

  • The Rotary Screen (B2 Thickener, 80 mesh size) is installed, it recovers the fibres by screening the filtrate of both the loops separately as per availability of filtrate. The improved filtration / screening improved the process water quality which can be recirculated in the process loop. At the same time, the   fibre recovery was improved which can be recycled in the process loop. 

  • The rotary screen was installed prior to clarifier, which recovers 50%-60% of total fibre which was earlier going into the sludge (0.103 Ton/day).

Economic benefits

With Capital investment of Rs. 18,00,000 and with minimum operating cost, industry saves Rs. 4,50,000 per annum (Fibre recovery cost only) giving a payback period of 4 years.

Contact details 

Mr. Banjul Shah, Director; banjul.shah@damanganga.com