Screw Blenders

From SolidsWiki
Jump to navigation Jump to search


Screw Blenders

Screw Blenders are common type of Vertical Mixers which excellent design alternatives for product applications that are shear sensitive, voluminous and also where space on the plant floor is at a minimum.

These mixers are widely used for mixing dry materials, paste, cream and lotions. The principle of blending is based on the differential travel speeds of product particles in the conical section of the vessel. The material from the bottom section of vessel is lifted by the screw and spread over the upper sections.


Features

  • The screw agitator turning on its axis produces a lifting action as it spirals the material in an upward flow
  • At the same time the screw orbits the tank , the screw removes material away from wall and deflects it into the centre of the tank setting up a spiral current throught the batch
  • The material lifted by the screw gravitates downwards thoroughly intermixing with material being spiralled upward
  • This results in most intimate intermingling of all ingredients


Advantages

Flexibility of Batch Size

Because of the vessel geometry and configuration the vertical cone screw blender can operate efficiently with batches as small as 10% of blender capacity. The ribbon blender generally requires a minimum of 40% of the total working capacity.

Homogenous Mixing

Better mixing efficiency and product quality are achieved in a vertical cone screw blender when compared to the ribbon blender.

Gentle Blending Action

The blending action of the slow turning mixing screw is very gentle. It is therefore suitable for friable and heat sensitive products.

Complete Discharge

The screw blender gives nearly 100% discharges through the lower cone.

Lower Risk of Contamination

The stuffing box is located above the working level of the material. As a result the material does not come in contact with the process material and the risk of product contamination is minimized.

Easy Cleaning

Screw blenders are easier to clean compared to the ribbon blenders since the stuffing box, packing glands do not come in contact with the process material.