pneumatic conveyor
Vacuum conveying enables hygienic transfer of materials, even on long and twisting routes
Pneumatic conveying systems
We design and manufacture pneumatic conveying systems in negative pressure both dilute and semi-dense phase, to meet the needs and requirements of the food, chemical, and plastic industries.
Dilute phase pneumatic conveying
They are used for example when is necessary to charge and weight content into powder mixers with multiple components, starting from different big bags or fully emptying previously batched hoppers.
It is an easy to install system, particularly suitable to convey food and potential explosive powders in a safe and clean way for long distances.
Gimat powder mixers have been studied to be under vacuum and filled up pneumatically, realizing a high speed and economical filling system, very easy to clean.
ATEX - Explosion Proof Protected
On request Gimat pneumatic conveying equipment can be designed and manufactured in compliance with the Directive ATEX 2014/34/EU FOR ZONE 2-22 / ZONE 1-21
features
Electric vacuum or pneumatic pumps
Easy removable filter groups, for fast cleaning
Perfectly dust-tight thanks to negative pressure inside pipeline
Direct suction into the vertical ribbon mixer
How does a pneumatic conveying system work?
Here an example of a typical pneumatic system designed by Gimat. A pneumatic conveyor system in the dilute phase empties the big bags. A cyclone separator is integrated in the vertical ribbon mixer. The content of the mixer is then transferred into a container holding the same blend of materials. To prevent the separation of the previously obtained product mix, a flexible screw conveyor is used to transport the blend.
In lean phase pneumatic conveying, the material to be conveyed is suspended in the airstream and the ratio of material to air is low (up to 5 kg product / kg air), meaning that the material is conveyed in a dilute phase.
In semi-dense phase pneumatic conveying the material to be conveyed is only partially suspended in the air stream and moves for the most part by sliding on the pipeline. The ratio of material to air is higher (up to 10 kg product / kg air), meaning that the material is conveyed with a higher concentration inside the tube and also lower speed is used.
In both cases the best way to regulate the material fed into the inlet point is using a rotary valve that dose the product into the air flow ensuring a correct and constant product/air ratio.
How to select the right pneumatic conveying equipment
The main factors we need to analyse to design a pneumatic conveying system for you are:
- Characteristics of the material to be conveyed (such as particle size and shape, bulk density, degree of abrasiveness and friability, moisture content, cohesion, explosiveness and others).
- Quantity of material to be conveyed (hourly transfer capacity to meet your production requirements).
- System installation: adaptation to the premises, volume constraints (available space, presence of other machinery, ceiling height), accessibility for maintenance.
Negative pressure semi-dense phase conveying vs. dilute phase conveying
The variety of cases we have dealt with over the past 50 years allows us to say that no two projects are the same, and the choice of one system over another depends precisely on the combination of many factors. Here, we summarise the general characteristics of both systems. Our R&D department has capitalised on the experience gained over the years to make the most of the advantages of both methods.
Semi-dense phase: pros and cons
- Preferable for fragile, mixed or abrasive materials.
- Cyclone filters with lower filtering surface thanks to smaller air amount.
- Less wear and tear: slower speeds reduce abrasion on the conveying system and components.
- Higher costs for pump and components.
- Requires more careful system design and control.
- Risk of plugs due to higher product concentration in the transport pipeline.
- More sensitive to the type of product conveyed.
Dilute phase: pros and cons
- Lower initial investment, easier to set up compared to dense and semi-dense phase systems.
- Can handle a variety of material types.
- High flow rates
- Reliable, easy to install and operate.
- Higher energy consumption (requires more power due to the high air amount needed).
- Increased abrasion on bends if not carefully designed.
- Material degradation: friable materials can break down due to the higher conveying speed.
- Separation of mixed materials (especially when the mix contains particles of very different sizes and bulk densities).