New innovations for the textile processing plants
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48 PTJ May 2009 German Review 1. Introduction WAG-Freiburg GmbH, established in Germany, has, together with its branch office in Karachi, Pakistan, developed new tech- nologies and equipment improving some processes in the textile processing thus reducing the overall costs. These can be summarized as under: De-ironing Filters: Removal of iron and rust in water, steam and caustic solutions with magnetic filters. Especially for bleaching processes or any other processes using water, caus- tic or steam. Wedge Filters: Filtration of fluffs from strong/weak lye of mercerizers, wastewater filtration, or all liquid filtration down to 50 micron. De-coloring of strong or weak lye from mercerisers in Denim, followed by weak lye evaporation (CRU process) and reuse of strong lye. Wastewater Pre-Treatment (1st. stage): Complete space saving and modular chemical treatment, de-coloring (Denim) and sludge separation. Wastewater total treatment: Total space saving plant with modular elements for future extensions. Water Recovery: out of wastewater, Re-use for processing. Caustic Recovery Units: (CRU) Weak lye evaporation from mercerisers. Silt Removal: specially for ground water. 2. De-ironing Filters Burnt-out holes on your fabric? Rusty stains? or even reddish spots? These problems are solved with customized magnetic filters by WAG Freiburg Engineering in Germany. De-ironing filters in the Textile Mills are recommended for de-ironing of supplied water to bleachers, J-Boxes, a.s.o, fresh water distribution, con- densate, steam and weak and strong lye. De-ironing of supplied water is needed especially for the bleaching process in order to avoid attack of hydrogen peroxide with iron which results in holes in the fabric. If de- ironing is not done, iron particles coming with the water supply shall slip causing damage to the fabric. The caustic solutions from out- side sources can also contain impu- rities with iron contents. This iron slippage into commercial caustic solution comes from corroded and dirty tankers and also due to ineffi- ciency of post filtration process during manufacturing of caustic soda. The Filters are specially conceived for the elimination of Iron particles for the textile industry. The coarse iron particles will be retained in a 100 ym sieve whereas the fine iron material will be sticking on strong magnetic elements placed within the sieve. This filter will separate all iron particles in suspension in water. 3. Wedge filters WAG Wedge filter is best applicable for the filtration of fibres, fluffs, and all materials which are normally difficult to filtrate under pressure. WAG Hydro-Wedge filter are especially effective at removing particles from 100 to 1000 ym. New innovations for the textile processing plants by Alain Geiser and Fawad Ahmed Sheikh. De-ironing filter for hot water. De-ironing for strong lye. Wastewater flows downward along the Wedge filter. The material to be filtered will be retained on the surface of the wedge whereas wastewater will flow filtered through it. Filtered out material remains on the surface of the wedge and is constantly pushed downward the wedge into a sludge tank. Wedge Filter, Denim WW. Wedge Filter, Wastewater. WAG-Freiburg GmbH is a small innovative company based in Germany looking to solve the problems in the textile industry and make textile manufacturing more economical. The company can also be visited at ITM Istanbul at Hall 6. In view of its serious commitment to industry in Pakistan and also upcoming in Nigeria, WAG have established their Representative office “WAG-Pakistan“ in Karachi.
Transcript of New innovations for the textile processing plants
48 PTJ May 2009
Ger
man
Rev
iew
1. Introduction
WAG-Freiburg GmbH, established in Germany, has, togetherwith its branch office in Karachi, Pakistan, developed new tech-nologies and equipment improving some processes in the textileprocessing thus reducing the overall costs. These can be summarized as under:� De-ironing Filters: Removal of iron and rust in water, steam
and caustic solutions with magnetic filters. Especially forbleaching processes or any other processes using water, caus-tic or steam.
� Wedge Filters: Filtration of fluffs from strong/weak lye ofmercerizers, wastewater filtration, or all liquid filtration downto 50 micron.
� De-coloring of strong or weak lye from mercerisers inDenim, followed by weak lye evaporation (CRU process) andreuse of strong lye.
� Wastewater Pre-Treatment (1st. stage): Complete spacesaving and modular chemical treatment, de-coloring (Denim)and sludge separation.
� Wastewater total treatment: Total space saving plant withmodular elements for future extensions.
� Water Recovery: out of wastewater, Re-use for processing.� Caustic Recovery Units: (CRU) Weak lye evaporation from
mercerisers.� Silt Removal: specially for ground water.
2. De-ironing Filters
Burnt-out holes on your fabric? Rusty stains? or even reddish spots?
These problems are solved with customized magnetic filtersby WAG Freiburg Engineering in Germany. De-ironing filters inthe Textile Mills are recommended for de-ironing of suppliedwater to bleachers, J-Boxes, a.s.o, fresh water distribution, con-densate, steam and weak and strong lye.
De-ironing of supplied water isneeded especially for the bleachingprocess in order to avoid attack ofhydrogen peroxide with iron whichresults in holes in the fabric. If de-ironing is not done, iron particlescoming with the water supply shallslip causing damage to the fabric.
The caustic solutions from out-side sources can also contain impu-rities with iron contents. This ironslippage into commercial causticsolution comes from corroded anddirty tankers and also due to ineffi-ciency of post filtration processduring manufacturing of causticsoda.
The Filters are specially conceived for the elimination of Ironparticles for the textile industry. The coarse iron particles will beretained in a 100 ym sieve whereas the fine iron material will besticking on strong magnetic elements placed within the sieve. Thisfilter will separate all iron particles in suspension in water.
3. Wedge filters
WAG Wedge filter is best applicable for the filtration of fibres,fluffs, and all materials which are normally difficult to filtrateunder pressure. WAG Hydro-Wedge filter are especially effectiveat removing particles from 100 to 1000 ym.
New innovations for the textile processing plantsby Alain Geiser and Fawad Ahmed Sheikh.
De-ironing filter for hot water.
De-ironing for strong lye.
Wastewater flowsdownward along theWedge filter. The material tobe filtered will be retainedon the surface of the wedgewhereas wastewater willflow filtered through it.
Filtered out materialremains on the surface ofthe wedge and is constantlypushed downward thewedge into a sludge tank.
Wedge Filter, Denim WW. Wedge Filter, Wastewater.
WAG-Freiburg GmbH is a small innovative company based in Germany looking to solve the problems in the textile industry and maketextile manufacturing more economical. The company can also be visited at ITM Istanbul at Hall 6. In view of its serious commitment toindustry in Pakistan and also upcoming in Nigeria, WAG have established their Representative office “WAG-Pakistan“ in Karachi.
PTJ May 2009 49
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an R
eview
3. De-coloring of waste Indigo dyes in denim processing
Applications for weak andstrong lye decoloring in mercerisersis given as under:
Weak Lye of mercerisers
The use of Indigo dyes in theDenim processing does not allowits recovery, i.e, its evaporation to astrong lye with a caustic recoveryplant (CRU). The Indigo dyes wouldblock off the evaporation processes.2-6 m³/h weak lye with a concen-tration of 3-7 Be are reported to godown the drains and in otherwords, it is “money down thedrains”.
Strong lye of Mercerisers
Strong lye have to be drainedperiodically due to the high Indigoconcentration. New strong lye solu-tion will have to be frequently setup.
WAG Freiburg has found aprocess to remove the indigo dyefrom the caustic solution using acombined physico-chemical process.After 6 months trial period, thesystem is presently being installed intwo Denim factories in Pakistan.
Wastewater decoloring
Wastewater from DenimProcessing is dark blue or black,which is unesthetical and gives theimpression of a poisonous waste-water at the drainage area. Denimfactories often have complaints fromthe surrounding population ororganisations.
WAG has installed 5 wastewater pre-treatment plants inDenim factories in the last 6 months, where not only Indigo blueor black are removed, but also a reduction of 30-40% COD loadis obtained and reported by the customers. These plants areworldwide unique for their flexibility, space saving (130 m² for 70m³/h) and modular conception.
Total wastewater treatment plants (physical and biological)can also be planed for all textile processing plants.
Process water recovery out of the cleared wastewater is pos-sible, but still not very economical for the time being.
4. Caustic Recovery units (CRU)
A few Multiple Falling Film Evaporators unit are in operationin Pakistan, (examples include, Gul Ahmed Textiles Mills Ltd).Along with the units tailor-made designed heat and water recov-ery unit for the entire process was also supplied, which is savingtotal water, and nearly the total heat energy input in theprocess.�
De-coloring- Indigo weak lyeafter treatment.
Indigo Weak lye.
De-coloring unit.
