Paste silos

Paste silos are containers for pasty, viscous or poorly flowing products. They serve as buffers, storage vessels and discharge units between a preceding process and the downstream plant. Unlike silos for bulk materials, pastes and highly viscous masses can form stable bridges and adhere strongly to the walls. Gravity and simple hopper shapes are therefore insufficient for discharge.

Paste bunkers are key links in process chains. They balance out different operating modes and buffer material flows. This allows continuous and batch-operating plants to be run independently.

Typical contents include:

• Filter cakes
• Slurries
• Doughs.
• Highly concentrated dispersions.
• Recyclates with a high proportion of fine particles and moisture content.

Such materials are used in the chemical, environmental technology, food and building materials industries. Paste bunkers feature internal discharge aids, for example:

• slow-running scraper arms
• screws
• helical agitators
• SinConcave mixing helical blades
• pneumatic floors or scraper floors.

The rotating discharge mechanisms detach the product from the wall surfaces and convey it in a controlled manner to the outlet. The paste bunker is often designed as a flat-bottomed silo. This design reduces the overall height and enables almost complete emptying across the entire base area. Discharge aids prevent dead zones and the risk of blockages. The mechanical discharge aid must be capable of transmitting high torques, particularly when dealing with compacted materials. On the other hand, shear stress and temperature rise for the product should be kept as low as possible. Its structure, viscosity and temperature should not change.