Besides pure material transfer, additional requirements can be placed on a vacuum conveying system. For example, a given batch weight is to be fed to a mixer or reactor or perhaps the material should not be delivered in one go but over a longer period of time as a constant material flow to aid mixing. So, sometimes, a combination of weighing and constant material delivery (dosing) is required.
These requirements can be met by a combined transfer and weighing conveyor (CONWEIGH) or by a dosing system placed at the product outlet of the vacuum conveyor.
Conveying and Weighing vacuum conveyor
CONWEIGH: The conveyor for transferring bulk materials can also be equipped with a weighing function, allowing for exact batch feeding of a mixer, reactor or container. For this purpose, the vacuum conveyor is weighed by means of load cells -pre and post transfer and thus the net weight of the contained product is determined. The filling of the receiving vessel can therefore be brought up to the target weight.
Dosing systems
Some processes require a continuous feed of a powder, granulate or other bulk material over a longer period of time. This may be a requirement for feeding a mixer or reactor, for example, where a bulk material is to be mixed into another product (or liquid).
With a dosing system, bulk material from a feed pipe, a storage container or other mass flow device is delivered to the downstream process evenly and with a predefined quantity over time. In this way, continuous product delivery can be achieved with a vacuum conveying system that operates in cycles.
Our product portfolio includes the following dosing systems:
Rotary feeder: The dosed discharge of bulk material from a container can be carried out by means of a rotary feeder. At the same time, the rotary feeder acts like an airlock which prevents the flow of air or gases from upstream or downstream processes.
A vibratory feeder can convey a variable flow of material from a hopper to a downstream process. Combined with a weighed buffer vessel, accurate metering can be achieved.
