Kufner Textilwerke (Germany)
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- 1. Case study or Built example
Case study
- 2. Industry Sector
Textile finishing of woven fabric, knitware and card web
- 3. Industrial application
Finishing (Dyeing): heat recovery system
- 4. Process description
- Flowsheet
[[Image:Flowsheet(Germany).jpg
Pic. 1: flowsheet: Kufner, textile finishing of knitware and woven fabric
Pic. 2: Kufner textile finishing of card web
- Processes
Production is done in 4-shift operation, 6-7 days per week. Production in 1999: 173.900.000 m2 or 13.500 tons of finished fabric.
Processed fibres: [mass%]
- CO 6 %
- CV 28 %
- PES 55 %
- PA 9 %
- WO 1 %
- Animal hair 1%
Finishing-products: [mass%]
- Card web 9 %
- Knitware 15 %
- Woven fabric 76 %
At the time when the project was carried out, woven fabric and knitware consisted to 56 mass% of synthetic material (PES, PA) and 44 mass% natural fibres (CO, CV, WO and animal hair). Card web consisted of Synthetics only (PES and PA).
Fabrics of natural fibres were washed / scoured in a continual washing-machine and afterwards dried on a stenters which was directly heated by natural gas. Fabric made of synthetic fibres was subjected to a planned dimension-change, which promotes elasticity and fullness. Unless this fabric is died, it will afterwards be dried.
Dyeing is done on jiggers (fabric mainly consisting of Cellulose) or on HT (fabric composition: 100% PES and PA). With jigger-dyeing, the temperature of the dye liquor can be close to 100°C, with HT-dyeing even 130°C. The required water is pre-heated via the installed heat-recovery-system to 50°C and the process-temperature is kept constant at 60°C with steam (Booster). Process temperature in the dyeing mill is adjusted by indirect steam-heating.
After “glazing” (“Appretur”) (“wet-in-wet” for dyed fabric, and “dry-in-wet” for wihite fabric), the fabric is mechanically dried with a foulard and a suction bar, thermally dried in SR and afterwards thermofixed.Accodring to customer demands, the fabric is coated (paste-/powder- or spot-coating). In a pre-dryer the coated fabric is dried or sintered. In the main dryer, the fabric is dried at temperatures up to 185°C. At the end of the coating aggreagate, there is a cooling-roll and a smoothing-roll.
The following finishing aggregates are in use:
Coating machines 3
Stenter frames 3
Dyeing machines 8
Washing machines 1
Cylindrical dryer 1
Plants for further pre-treatment 2
Plants for further final treatment 2
- 5. Energy flows and temperature ranges
- Main heat supply system and fuel:
Heat production: steam, direct firing, thermo-oil and heat recovery system (dyeing)
Energy supply: natural gas + electricity (1999: 17% electricity, 83% natural gas) Total energy consumption in 1999: 31 242 MWh Electricity consumption in 1999: 5 333,5 MWh Natural gas consumption in 1999: 2 785 871 m3 or 25 909 MWh
- Energy consumption:
Electricity consumption:
Electrical power of certain loads – Kufner HB:
All electrical loads were operating 7390 hours in 1999.
Natural gas consumption – 1999 Kufner:
1 coating system
2 stenter frames
3 thermo-oil boiler
4 boiler house
5 pre-treatment machines
Gas consumption – 1999 Kufner:
- Temperature ranges and other parameters:
The dyeing process-temperature is kept constant at 60°C. In a pre-dryer the coated fabric is dried or sintered. In the main dryer, the fabric is dried at temperatures up to 185°C.
- 6. New technology’s description
- Picture of the scheme
1 fresh water tank
2 fresh water
3 process-water cold
4 steam
5 process-water hot
6 waste-water heat-exchanger
7 waste-water tank
8 dyehouse
9 booster
10 hot water tank
- Heat recovery system (dyehouse)
Waste water coming from the dyehouse is being separated in “hot” and “cold” water by a temperature switch, which is adjusted to 40°C. Cold water is piped via the in-house canalisation to the communal system and warm water is collected in a waste-water pool. From here, it is piped to the central two-stage heat-recovery system. A large amount of the heat is extracted there.
- 7. Energy savings
- Pinch analysis results
No information is available.
- Energy savings:
No information is available.
- 8. Economic evaluation
- Economic parameters:
No information is available.
Source: “Potential for the reduction of CO2 emissions through rational energy use in textile finishing”, Bavarian Federal Office for Environmental Protection, December 2000, Bavaria, Germany (“CO2-Minderungspotentiale durch rationelle Energienutzung in der Textilveredelungsindustrie”, Bayerisches Landesamt für Umweltschutz, Dezember 2000, Bayern, Deutschland)
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