Contra Rotating Mixers

Contra rotating mixers

Contra rotating mixers are typically used when thick emulsions are produced by a bottom entry emulsifier or homogenizer. They are also very useful for multi task vessels where different process duties are required.

Advantages

Contra rotating mixers have the advantage of utilizing the benefits of a turbine unit with the benefits of an anchor / scraper. Contra rotating mixers offer excellent mixing throughout the vessel as viscosities increase due to their double mix system. A contra rotating mixer is fitted with two drives; an anchor / scraper drive and a centrally mounted turbine drive. In effect it is two mixers joined together. The wet end can be complete and installed into the tank prior to the vessel being completed or can be fully split to allow simple installation / removal.

Areas of Applications

The mixer is highly versatile and mostly used for manufacturing Tooth Paste, Creams, Cosmetics and other viscous products.

Operation Principles

Contra Mixer as the name suggest works on the principle of Contra rotation of Blades for simultaneous beating and scraping operation. The Mixing Assembly consists of series of paddle type blades of appropriate shape to move the material back towards the centre of the container. The paddle type blades are provided on the central shaft which runs through a hollow shaft on which other sets of blades are welded. Both the sets of blades intermeshes with each other and rotates in clockwise and anti-clockwise direction respectively and one sets also scraps the container wall for thorough and uniform mixing of the material.

The mixer is so designed to withstand high vacuum applied during the process for optimum mixing. Contra Mixer is provided with a jacket for cooling or heating as per the application. The vessel shall have a shell of suitable thickness with a hemispherical bottom and flanged top dish made out of S.S. 316 plate. The vessel shall be jacketed with MS jacket ( SS304 jacket provided on extra cost on demand, if required ) of suitable with stiffeners suitable for steam pressure of 4 to 5 Kg/cm2. The jacket shall be insulated with 50 mm thick glass wool insulation and shall be cladded with 16 SWG M.S. or SS304 material. The vessel shall be suitable for 600 to 700 mm of Hg vacuum and internal pressure of 3 Kgs / cm2.