07-11-2012, 05:59 PM
POWERHOUSE MAINTENANCE & BAGASSE PLANT AT CENTURY PULP & PAPER
POWERHOUSE MAINTENANC.docx (Size: 608.73 KB / Downloads: 157)
INTRODUCTION:
Century Pulp & Paper , a unit of century textiles & industries Ltd , and a member of B.K Birla group of companies . The chairman of the company is MR B.K KUMARJI BIRLA .CPP was established in 1984. location of the plant is at lalkuan on Bareilly-Nainital road , 5 Km from Pantnagar towards Haldwani.the company is pioneer in Bagasse based Paper manufacturing throughout the country.
POWER BLOCK:
Power block has 9 coal & pith fired boilers & 3 turbines. The turbines are of 6.8 MW BHEL T.G SET(extraction back pressure), 21MW T.G set & 16 MW BHEL turbine , 43 MW T.G Set (all are double extraction condensing type).
8 boilers are fluidized bed boilers out of which there are one F.B.C Boilers of 100 T/hr , 62 kg/cm2, 480 degree celsius, three F.B.C Boilers are of 23 T/hr ,47 atm , 420 degree celsius each, two F.B.C Boilers are of 50T/hr , 63 atm, 480 degree celsius each, one boiler is spreader stoker coal fired boiler of 25T/hr, 47 atm , 420 degree celsius, one boiler is coal cum pith fired boiler of 60T/hr ,66 atm, 485 degree celsius & one new coal fired boiler of 100 T/hr , 65 Kg/cm2 , 480 degree celsius.
CHEMICAL RECOVERY PLANT:
Chemical recovery plant recovers cooking chemicals spend during cooking operations in the digesters with the help of latest technology avialable. These chemicals are resued in cooking operations in pulp mill. The liqour received in pulp mill is called black liqour and the liqour supplied back to the pulp mill is called white liqour based on their colour appereance. The black liqour contains substantial amount of organic matter like lignin which when burnt in recovery boiler along with black liqour , releases enormous amount of heat which is utilised to generate high pressure steam and is sent to the turbines to generate power. The black liqour is first concentrated in evaporators , then burnt in boilers & thereafter is reacted with lime (calcium oxide) in causticizing section to finally recover the spent chemicals. Make up sulphur & lime stones are added in the system as per requirement. Lime is produced in rotatory lime klin by burning the mud (calcium carbonate) obtained from causticizing section.
COMMITMENT TO QUALITY & SERVICE:
At century, quality is an all pervasive commitment . It strive to continually improve the quality of their products and services , which have been , affirmed in the form of ISO 9001;2008 certification to the company for its quality management system. The company has been responsible to the changing market requirements and has developed new quality products to care to the varying end uses.
CARE FOR ENVIRONMENT:
Preserving & protecting the environment is a top priority at century. It is always sensitive to it’s boi- diversity of the soil , water & air around them. CCP’S power plant maintains an efficient system for reducing air emissions . Electrostatic precipitators have been installed to remove particulates from recovery boilers , coal fired boilers and lime klin flue gasses.
In strict adherence to the standards & guidelines , the effluents are treated in a modern FTP , which is recognised as the model plant for its efficiency & performance. Company’s adoption to a systematic approach to the environment matter including waste minimization , water recycling & reuse programs of by products has faciliated the company in getting the ISO-14001;2004 certification for its environment management system.
Company’s friendship with environment has also reflected in its Bagasse based paper , been licenced for eco labelling , a distinct honour to be attained.
PROCESS DESCRIPTION:
the company has three streets of production viz., W.P.P , BAGASSE , R.G.P plants. A wide variety of writing & printing paper is manufactured in W.P.P & Bagasse plant and Rayon grade pulp is manufactured in R.G.P plants.
The main steps in manufacturing PAPER/ RAYON grade pulp is as shown:
1. Chipping of the logs of Bamboo , Eucalyptus/ popular in W.P.P streets & Eucalyptus in R.G.P street to about 1 size chips & storage in chips sallow.
2. Bagasse unloading, handling, depithing, pile building, reclaiming & washing in Bagasse street.
3. Cooking-sulphate process: in W.P.P & R.G.P streets, vertical batch digesters (for chip cooking) & in Bagasse street, continuos tube type digester (forBagasse fibre cooking) are in operation. The cooking process is carried at a preset temperature and pressure of cooking chemicals for special cooking period.
4. Removal of Knots/uncooked/partially cooked portion of the material obtained from the digesters on the knitters.
5. Washing of pulp in brown stock washers to remove spent chemicals & organic matters.
6. Screening & cleaning of the pulp to remove impurities.
7. Bleaching of the pulp based on special technology to attain final pulp brightness as per requirement.
POWER PLANTS:
A power plant may be defined as a machine or assembly of equipment that generates and delivers a flow of mechanical or electrical energy. The main equipment for the generation of electric power is generator. When coupling it to a prime mover runs the generator, the electricity is generated. The type of prime mover determines, the type of power plants. The major power plants are:
1. Steam power plant
2. Diesel power plant
3. Gas turbine power plant
4. Nuclear power plant
5. Hydro electric power plant
The Steam Power Plant, Diesel Power Plant, Gas Turbine Power Plant and Nuclear Power Plants are called THERMAL POWER PLANT, because these convert heat into electric energy.
But here ,at cpp we greatly deal on the steam power plant i.e one of the thermax power plant , which depend on the thermal fuel i.e coal & liquor.
The known resources of coal in India are estimated to be 121,000 million tonnes, which are localized in West Bengal, Bihar, Madhya Pradesh and Andhra Pradesh. The present rate of
annual production of coal is nearly 140 million tonnes of which 40 million-tonnes are used for power generation. The coal used for power generation is mainly low-grade coal with high ash content (20-40%).The high ash content of Indian coal (40–50%) is one of the causes for bad performance of the existing steam power plants and their frequency outages, as these plants have been designed for low ash coals. Due to the large resources of coal available in the country, enough emphasis has been given for thermal Power plants & here in CPP too.