In the forefront

HNL has always maintained an edge in technology. Following are a few instances of the use of modem technology by HNL.

  Used Hydrogen Peroxide for bleaching which resulted in better bleaching and lesser pollution.

  Installed and later upgraded the computer based Quality Control System for Paper machine.

  FBC conversion of Boilers.

  Introduction of DCS system for all mill process operations.

  Lime sludge re-burning plant for recovery of chemicals.

  Energy efficient Falling Film Evaporator and Finisher in Recovery plant.

  Installed Fiber Optic LAN for mill- wide Computer networking.

  Implemented Enterprise Resource Planning (ERP) software, BaaN for all business activitives.

BRIEF DESCRIPTION OF PROCESS FLOW

 Chemi Mechanical Pulp (CMP)

 230 BDMT per day CMP plant (Sunds Defibrator, Sweden) uses hard wood chips to produce pulp. Chips are washed, presteamed and impregnated with caustic soda. Impregnated chips after recovering spent alkali is mechanically pulped using three Raffinators (RL 58”) in series. Raffinators are driven by synchronous motors of 6.5 MW (BHEL make). Spent chemicals are removed after primary refining using  Twin roll press. Pulp after second stage refining is washed and bleached by Hydrogen Peroxide. The TCF bleaching process operates effluent free. Bleached pulp after third stage refining is sent to High Density storage tower for onward use in paper machine.

 Chemical Pulping (CP)

 Reed/ Bamboo chips are pulped using conventional sulfate process using stationary vertical Digesters of BHPV make. After counter current washing, pulp is bleached using chlorine followed by Hydrogen Peroxide stage.

 De-Inking Plant (DIP)

 The 100 TPD De-Inking Plant uses Old Newspaper (ONP) and Old Magazine Paper (OMG). Waste paper is weighed and pulped in Batch Pulper and stored in Dump Tower. Pulp is cleaned off the contaminents using HD cleaner followed by 2 stage hole screening. A seven cell floatation process (5 in primary and 2 secondary) removes the ink  from pulp. Pulp is further cleaned in 4 stage centricleaners followed by 3 stage slot screens. Pulp is thickened in Disc filter and Screw Press to 30 % driness and subjected to hot dispersion. Pulp is then bleached using Sodium Hydrosulfite and stored in High Density storage tower. A Reject handling system separates the rejects for disposal at about 50% dryness. The sludge handling system thickens the ink sludge to 40% dryness for use in our FBC Boilers.

Into Paper Machine

The CMP, CP and DIP are mixed in a definite ratio and supplied to the headbox through approach flow system wherein additives are added. The paper machine approach flow system consists of four-stage centri-cleaner, Clark and Vicario Deculator system, primary fan pump and a variable speed secondary fan pump and pressure screens.

 The paper machine is the modern high speed machine from JM VOITH GmbH, Germany. With the desired velocity, the diluted pulp flows from a high turbulance W-type head box into Duoformer twin-wire forming section. The paper web is formed in Duoformer and it is pressed to remove water with swimming rolls. The paper from the press section passes on to a dryer section, with 36 dryers and one sweat dryer, having thermo-compressor steam and condensate system. The dried paper surface is smoothened through a four roll open calendar stack with two Kusters swimming rolls.

 The machine is designed for 750 meters per minute (mpm) speed with a deckle (width) of 6.85 meters to produce 44 to 54 GSM newsprint. The machine has a sectional D.C. drive with thyristor control. The finishing line has a VOITH winder, Jagenberg Salvage winder and Klienewefers roll wrapping machine. Paper core is made here in a spiral core making machine with purchased kraft paper and grey board.

 The Utilities

 The steam requirement is met by 3 AVB/ ABL boilers with fluidised bed burning. There is a chemical recovery boiler of BHEL make. The turbo generator has a capacity of 15 MW. About 50-55% of total power requirement is met through State Electricity Board. Also the mill has an effective water and air supply system for plant use and controls.

 Effluent Treatment

In keeping with National priorities and increasing social obligations, HNL has adopted environmental and pollution control measures. The colour and other pollutants are removed and water free from pollutants is discharged to the river. Air pollution is also controlled by effective Electro Static Precipitators.

Aerators in HNL's Lagoon