Ergonomic and safe reactor filling
How can you load a reactor with the correct amounts of different powders, some even showing bad flow characteristics, without creating dust clouds, in a safe way for both the process and its equipment but also for the operators minimizing material handling operations of the bulk raw materials?
For all these questions Gericke has found the right answers by combining vacuum and positive pressure pneumatic conveying systems.
For a global player in specialty chemicals Gericke were challenged to unload different powders delivered in small bags into several large reactors with volumes of more than 100 m3. The traditional filling method of tipping directly above the reactor through an inlet required lifting all the bags from ground floor up to a height of more than 12 m creating several safety and ergonomic issues.
The Gericke solution was to install a bag unloading station on the ground floor eliminating much of the bag handling by the operator. The large opening of the bag unloading station is designed to unload 20 kg bags of a very light filter aid powder. During unloading bags into the tipping station a vacuum conveying system, fed by a discharge screw installed at the bottom of the bag tipping station, sucks the material away. This allows even bad flowing powders to be emptied easily. The vacuum system transfers the powders from the bag tipping station into a large receiving vessel. This vessel is on load cells so the weight is protocolled and checked at all times ensuring that the correct batch weights are filled. The full recipe of powders is unloaded in this way with a total batch size of 50 – 400 kg of all involved powders filled into the receiving vessel.
The vacuum receiver vessel then changes its function and unveils its second ability to act as a pressure vessel suited for dense phase positive pressure conveying. A carrier gas, in this case pressurized nitrogen due to the process conditions in the receiving reactors, is used to transfer the material. Before starting the transfer from the Gericke pressure vessel the receiving reactor is put under vacuum. The dense phase conveying system consumes only limited nitrogen so the scrubber on the reactor can be kept closed during the filling process reducing the vacuum in the reactor slightly.
The complete batch is emptied from the pressure vessel and filled into the reactors that are situated over 30 m away from the tipping station. With this arrangement the tipping area is isolated from the reaction area. With positive dense phase conveying systems conveying distances of more than 100 m are feasible.
During the project Gericke tested and proved the function of both vacuum and positive pressure dense phase conveying systems in its test facility in Regensdorf (Switzerland).
About Gericke
The Swiss Gericke Group has been designing and manufacturing equipment and systems for modern
bulk material processes, as well as providing design and consultation services, for more than 125 years. Gericke bulk materials processing technology can be found throughout the world in many sectors including the food, chemical, pharmaceutical, plastics and construction material industries.
Gericke’s fully owned group companies employ more than 300 experienced professionals and are located in Switzerland, Germany, Great Britain, The Netherlands, France, USA, Brazil, Singapore, Indonesia, Malaysia, Thailand and China.