用于纸和纸浆行业的离子交换树脂
水是制造纸张和纸浆的重要材料，并且被大量使用。这始于作为原材料的木浆，并涉及其在巨型造纸机中的应用。在这些巨型造纸机中，纤维素纤维从水悬浮液中分离出来，然后逐渐排出。最后，生产出来的纸张以高达每分钟约2000米的速度卷绕到卷筒上。这种高生产速度使可再生工艺条件的严格的要求成为必要，这些要求必须被严格的遵守。
为了确保这一复杂的过程可靠的工作，并生产出始终如一的高质量纸张，所用的水也必须符合严格的要求。水质越好，生产优质纸张的可靠性和效率就越高。特别是溶解成分的类型和浓度，无论是无机盐还是有机分子，都必须在狭窄的范围内保持恒定。
我们的LewaPlus®设计软件可以在量身定制的基础上对离子交换树脂和交换阶段的各种组合进行建模，并分析其性能。这为用户提供了最大的信心，即他们将获得相关给水的最佳处理解决方案，和给定情况下所需的工艺水质。
在任何使用蒸汽的地方，离子交换树脂也是必不可少的，例如在制浆过程中的加热水箱，或干燥纸幅。与火力发电厂一样，它们确保水蒸汽回路可靠运行，几乎不需要维护。这需要对补给水进行仔细处理，还需要高性能的冷凝水抛光。
最后，工艺水再循环对于制造过程的可持续性和成本效益至关重要，尤其是因为造纸工业使用了大量的水。即使这在今天已经基本实现，仍有改进的潜力。这适用于使用来自干燥器的潮湿废气的机罩冷凝物，例如，在热回收过程中与废气分离的机罩冷凝物。
对于这些和其他应用，朗盛提供全方位的特殊离子交换树脂，可根据特定要求量身定制。现在就找到最适合您需求的产品吧。
Having as few dissolved substances such as iron, ammonium, calcium and magnesium salts as possible in the process water provides the most favorable conditions for paper manufacturing. Only then can various paper chemicals such as optical brighteners, colorants, fillers, and retention agents take optimum effect. That is why the fresh water used for paper manufacturing in Germany is generally of potable quality.
Lewatit® ion exchanger types can be combined to beneficial effect to soften or even completely desalinate (demineralize) the fresh water. This allows the water required to be obtained reliably and economically. When used paper is used as a raw material along with or instead of native pulp in particular, calcium salts from fillers that it contains can enter the process water in larger quantities and also increase water hardness.
Our Lewatit® ion exchangers are used in paper plants around the world to ensure, for example, that added optical brighteners give the paper the highest degree of whiteness by reliably removing ionic, organic compounds such as humic acids from the process water. Such humic acids even absorb UV light and would otherwise compete with the brighteners.
Through droplets that are carried along when the paper is being dried, salts – together with a variety of organic compounds from the white water – find their way into the hood condensate. Using LewaPlus® software, a multi-stage solution for treatment can be calculated based on the results from the analysis of this condensate from the heat exchangers.
Since the hood condensate is less polluted than standard feed water that is used, it can be assumed that ion exchangers can be successfully used for purification. The resultant water can be fed into the process water cycle. Following an increase in the pH value, sufficient reduction in water hardness, and a reduction in organic impurities, it can also be mixed with the make-up water.
Steam boiler manufacturers provide detailed specifications for feed water based on VGB guidelines (e.g. max. electrical conductivity; silicic acid, sodium, and organic compound content) in order to ensure optimal operation. For example, forced-circulation boilers that are operated under high pressures of up to 290 bar and at hot steam temperatures of 600 °C require very pure, desalinated water. This is the only way to prevent turbines, for example, from becoming corroded, contaminated, or damaged or to avoid deposits forming there.
The usual sources for feed water are well or surface water, reused waste water, and seawater. This variety makes clear that the treatment steps also need to be configured individually. Our LewaPlus® design software is suitable for this.
In most cases, the make-up water is conditioned with ammonia in the water-steam circuit in order to create an alkaline environment, which aids corrosion protection. Nonetheless, impurities are created during operation in a water-steam circuit, which for the most part find their way into the condensate in the form of ions.
Moreover, even very small leaks can allow the ingress of organic compounds that then increase the risk of corrosion or lead to foaming under the extreme pressure and temperature conditions in the boiler. Therefore, treatment with ion exchangers is sensible or necessary in many cases in order to ensure reuse of the condensate as make-up water.
