有人將噴淋浸泡清洗稱為化學(xué)脫脂,也就是說高壓噴淋清洗是靠脫脂劑的皂化作用、乳化作用和分解作用來去除鋼帶表面的油脂的。
Some people call spray immersion cleaning chemical degreasing, that is to say, high pressure spray cleaning is to remove the grease on the surface of steel strip by saponification, emulsification and decomposition of degreasing agent.
(1)皂化作用。如果冷軋工序使用的軋制油主要是采用動物油和植物油配制而成的,這種類型的油通稱為皂化油。在脫脂過程中堿組分能與這些不溶于水的油類發(fā)生反應(yīng),生成能溶于水的肥皂,從而去除。反應(yīng)式為
(1) Saponification. If the rolling oil used in cold rolling process is mainly made of animal oil and vegetable oil, this type of oil is generally called saponified oil. In the degreasing process, the alkali component can react with these insoluble oils to form water soluble soap, which can be removed. The reaction formula is
(2)乳化作用。如果軋制油中存在礦物油。它屬于非皂化油,基本上不能與堿發(fā)生皂化反應(yīng),則必須靠表面活性劑的乳化作用來去除。
(2) Emulsification. If there is mineral oil in the rolling oil. It belongs to non saponified oil and can not react with alkali, so it must be removed by emulsification of surfactant.
表面活性劑能降低水表面的張力,這樣就能使本來平鋪在鋼帶表面的油膜卷離成小油珠,從而乳化。而且表面活性劑還能在乳化了的油珠表面形成一定厚度的界面膜,使乳化液比較穩(wěn)定,油污質(zhì)點懸浮于清洗液之中,不再沉積到鋼帶表面。
The surfactant can reduce the tension of water surface, so that the oil film on the surface of steel strip can be separated into small oil droplets, thus emulsifying. Moreover, the surfactant can form a certain thickness of the interfacial film on the surface of the emulsified oil beads, so that the emulsion is relatively stable, and the oil particles are suspended in the cleaning liquid and no longer deposited on the surface of the steel strip.
(3)分散作用。高壓噴淋清洗對于鋼帶表面不溶于水的固體污垢的去除,就靠表面活性劑的分散作用。離子型的表面活性劑能在固體顆粒表面被吸附,使所有的粒子都帶有相同的電荷,從而相互排斥而分散開來。此時表面活性劑的親油基定向排列于固體顆粒表面,親水基朝向水中。這樣也可使清洗液與固體粒子的界面張力小于粒子之間的內(nèi)聚力,防止粒子再聚結(jié)在一起。
(3) Dispersion. High pressure spray cleaning for steel strip surface insoluble in water solid dirt removal, depends on the surfactant dispersion. Ionic surfactants can be adsorbed on the surface of solid particles, so that all particles have the same charge, so that they repel each other and disperse. At this time, the lipophilic groups of the surfactant are oriented on the surface of the solid particles, and the hydrophilic groups face the water. In this way, the interfacial tension between the cleaning solution and the solid particles is less than the cohesive force between the particles, thus preventing the particles from coalescing again.