Abstract: A fluid mixing and blending system employs a fluid mixing passage having two or more discrete, individually controllable mixing elements located along the mixing passage. The use of a single mixing passage with multiple mixing elements, such as venturis, assures consistent and precise mixing, with a system which is economical to produce.

Abstract: The present invention provides a metal brightener and surface cleaner, which provides significant etching of aluminum and other metals, without detrimentally affecting other surfaces such as painted surfaces, glass, rubber and plastic. The inventive composition is especially suited for aluminum brightening for large vehicles, and may be utilized in an alkaline step of a multi-step vehicle wash. One of the exemplary compositions includes an alkali metal hydroxide; a polycarboxylic acid; an alkali metal salt of an organic acid; a first, amphoteric surfactant; a second, betain surfactant; and a third, nonionic surfactant.