With personal protection and a safer workplace in mind, in mid-2015 an existing customer requested Dinnissen to think along about a solution for the automatic emptying of 200 dm³ drums containing toxic/ explosive powdery products.
The reason for this was that although the drums were already being emptied mechanically at the existing customer’s premises, the employees had to wear gas masks during the emptying of these drums, which is undesirable, especially for long periods of time.
In the course of 2016, Dinnissen’s specialists set to work and, in conjunction and regular consultation with the client, they developed a fully 3D-animated pre-engineering in order to present the first draft designs.
The first draft designs were received with so much enthusiasm that by the end of 2016, Dinnissen was awarded the contract. This was the beginning of an exciting process of adaptations, improvements, unique innovations and frequent consultation with the client.
In early 2018, after more than a year of development, testing and improvement, the worldwide first of this truly unique automatic drum-emptier was a fact. The process starts with the supply of the closed drums, which are placed on the roller conveyor via the operator. After the ‘release signal’ and confirmation that the installation is ready, the drum is transported towards the first cabin.
Opening of the drum: first part
During the first operation, the lid is removed from the drum fully automatically with a special head piece, after which the lid remains clamped in this head piece. The drum is transported to the second cabin through an airlock. In the meantime, the clamped lid is pushed out of the head piece and placed on another conveyor belt. The lid that has just been removed is then transported to a separate cabin and cleaned with a neutral liquid, so after cleaning, it can be removed from the installation without any risk.
Inliner: second part
From the first cabin, and after removal of the lid, the drum now arrives in the second cabin. Because in some cases the drums are provided with a separate ‘inliner’ (a – usually – plastic lining on the inside of the drum) a provision had to be made to allow the operator to easily remove it. For this reason, the second cabin is provided with a special hatch that allows access not only to remove the inliner, but also to easily remove any powder residue. To further optimise accessibility and workability, the drum is positioned on a specially developed turntable, so the operator can work quickly and efficiently.
Emptying the drum
After the previous operation, the still filled drum is transported to the third cabin via another roller conveyor. Here the drum is fixed by a gripper arm, which rotates and empties the drum. At the express request of the client, this gripper arm is infinitely operable by the operator by means of a two-hand operation. This is a major advantage. After all, it allows the operator to look into the rotating drum and assess whether the use of a specially positioned ‘beater’ is necessary to knock any powder residues from the drum. In the meantime, possible powder chunks are reduced in size by a self-developed breaking knife.
Both the inliner, if there is one, and the removed powder continue their way via the roller conveyor, with the inliner being automatically transported to the shredder and shredded. Because these flakes may still be contaminated with the toxic/explosive residual product, they are stored in a special container that is eventually filled with a cleaning liquid. After a certain time, this liquid is drained and the flakes can be repacked and safely disposed of.
Last step: cleaning the drum
After emptying, the drum is returned to the starting position with the same two-handed operation and transported to the cleaning cabin via the roller conveyor. Here the drum is fully automatically clamped, lifted, turned over, brought into the desired cleaning position and rinsed out with a large amount of liquid, then blown dry with compressed air and placed back on the roller conveyor, after which the clean drum is fully automatically released via a secured hatch.
For the sake of additional safety, each cabin is regarded as an isolated space, which can be locked securely by its own automatic doors or shutters. If required, the operator can inject nitrogen into any cabin containing potentially explosive products, eliminating the chance of a possible explosion. The installation is also equipped with a built-in air dryer, including filters that prevent vapours from spreading through the installation. Another equally innovative measure is the constant negative pressure, which ensures no toxic/explosive vapours can escape when the drums are introduced or released.
Naturally, the complete electronic control and monitoring, including visualisations, have been developed and implemented by Dinnissen. All in all, this is a technical tour de force which will be highly regarded worldwide.
Article contributed by Dinnissen Process Technology, The Netherlands