Printing and dyeing belong to the three high industries with high energy consumption, high water consumption and high pollution. The annual wastewater discharge accounts for about 14% of the national industrial wastewater discharge volume, which indicates the large proportion of its water consumption .
The national water use quota for printing and dyeing companies is continuously increasingThe current limit of water consumption for the 100m standard products of existing printing and dyeing companies is less than 2.5 tons ;
The limit for newly-built reconstruction and expansion of printing and dyeing enterprises is less than 2 tons/100 meters of standard products ;
The advanced value required by the Cleaner Production Standard is less than 2 tons per 100 meters of standard products;
The shortage of water resources led to rising water prices, and the price of tap water was between 3-5 yuan/ton. Wastewater treatment costs between 3-5 yuan / ton, so many printing and dyeing plants cost about 8 yuan per ton, and most printing and dyeing companies daily water consumption of several thousand tons. According to statistics, the cost of water consumption accounts for about 4-6% of the processing value. At present, the average profit of printing and dyeing companies in many regions is only about 6% of the output value. Therefore, water consumption has a great impact on the operation of printing and dyeing enterprises. Great influence. On the one hand the country's water quota regulations, reach metrics face penalties or even stop off elimination. On the other hand, the high cost of money indicates the seriousness of water for printing and dyeing.
At present, a large number of printing and dyeing plants use a small amount of production, but the final reported unit product water consumption is up to standard, in fact, there are many artificial calculation factors at work, that is, when the various products converted into standard products, the width There is artificially high allocation of the width coefficient and the weight coefficient, so that the yield per unit can be increased and the unit water consumption can be achieved. There are also some factories, although the access and consumption of new water is not very high, but in fact it is by investing a lot of funds to do a lot of work on the reuse of water. The actual water consumption per 100 meters of product is still very large. Therefore, the actual production of water is used in what place, can minimize the amount of water, dyeing and dyeing water in-depth study and refinement of management is a common topic.
2 Water analysis
To fine management, we must first analyze water consumption as much detail as printing production process, analyze the absolute amount of each step and the proportion of water to determine management priorities.
Taking dyeing production as an example, the dyeing production water can be generally divided into three parts: pretreatment, dyeing, and post-finishing. Among them, the finishing water is usually the water used for preparing the finishing liquid with softening agent or other finishing agents, the washing tank water, and the setting machine cooling roller water. The amount of water used for the finishing liquid is 70.80% of the weight of the fabric, and there is not much water in the washing rolling groove. All the cooling roller water can be recycled and used, and does not consume. Therefore, the converted water consumption per 100 meters of product is about 30kg/100m.
Intermittent dyeing process water is divided into three parts: pre-treatment - Dyeing - washing, dyeing or pretreatment process water can be calculated, the weight of the fabric l: 8-10, provided one hundred meters fabric weight of 35-40kg, each staining is a water 280-400kg, the cooling water of the dyeing process, the steam condensate is all the recycling may not be included in consumption.
So the total amount of water pre-treatment process of dyeing production, dyeing and finishing of available statistics as follows:
Water consumption (tons)
Water consumption (tons)
Bath ratio
1: 8
1:IO
Pre-treatment process water
0.28
0.35
Pre-treatment washing water
0,28
0.35
Dyeing process water
0.28
0.35
Dyeing water for washing
0_28
0 35
Finishing water
0. O3
0.O3
total
1 15
1.43
Assuming a weight of 35kg per 100m fabric, if the other washing water is not counted, the necessary pre-processing, washing, dyeing, washing, and finishing the entire process of water consumption is l . 15-1 . 43 tons / 100 meters , and the actual water consumption of many factories before the no mark is above 3 tons / 100 meters . Compared with pure process water consumption is 1 . 15-1 . 43 tons / 100 meters , and the actual production of water 3 tons , the gap is 1 . 57-1 . 85 t / meters, the actual production can be seen in the water consumption of each track is mostly the washing process, as well as of the material, washing tub, washing vat and the like. Therefore, the focus of water management should pay attention to the repeated washing process and the repeated rework of products. Of course, all kinds of cleaning water should also pay attention.
3 The importance of water
The importance of water is not only reflected in the total amount of water companies to control water control costs, more important is how much water vapor has a great influence on the stability of energy consumption and production quality. The steam used in the printing and dyeing process is usually a heating treatment liquid or a dyeing liquid and a water washing liquid . The better the control of the amount of water used, the lower the amount of water used, the lower the heating steam will be. Therefore, saving water is the basis for saving steam.
The quality stability of the production process has a great relationship with the bath ratio . If the accuracy of water control is improved , not only the water consumption is decreased , but also the accuracy of the dyeing quality is improved , the stability is improved , and once the success rate is increased , the water used for feeding , repairing, and the use of electricity and electricity are reduced , so the water saving is energy saving. A basic job of reducing emissions, rather than a simple water cost issue.
4 Fine management of water
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