Extrusion die cleaning
PCA already built many plants for wastewater treatment and process water production in the aluminium pre-treatment industry. In this way, the step towards cleaning aluminium extrusion dies was taken. Meanwhile, PCA has already built several installations which, by using NaOH, clean extrusion dies.
To design such an installation, we sat down with a number of aluminium extruders. A number of basic conditions were confirmed:
- Automatic: without manual handling by the operator
- The operator never comes in contact with NaOH
- No fumes are released in the hall
- The unit is ATEX compliant
- The cleaning process must be fast and controlled
- Controlled re-use of NaOH
- No automatic crane as it is sensitive to malfunctions and expensive to maintain
- Minimal discharge of contaminated flows
Starting from these basic principles, we developed an installation with a corresponding process. The installation consists of process tanks in which all processes take place. Specifically, this means that both the cleaning of dies with NaOH and the rinsing with water take place there. In addition, the installation ensures that the liquid is always in motion, which in turn makes the process go much faster.
Since all the processes take place in one and the same tank, the dies don't need to be transported from one tank to another. The operator therefore doesn't need to intervene during a cleaning cycle.
Flexible elaboration of the installation
Because we design our installations entirely in-house, we are also flexible in their elaboration. The process tanks can be adapted to any existing baskets, available space, etc.
Usually, the tanks are built in stainless steel 304, but 316 is certainly an option as well. Moreover, all tanks are equipped with insulation to limit the heat losses.
Given the scarcity of liquid NaOH in 2022, and consequently high prices, we may also expand the installation with a system to use NaOH granules. The NaOH granules are placed in a hopper and the system will then automatically dose them in the mixing tank. In this way, we guarantee operation reliability, even when liquid NaOH isn't available.