FRELP: progress in June 2014
The four steps of the plan of development, the situation is as follows:
1st step Detachment of aluminum profiles and connector (ACTION B3)
This action has been fully resolved at the design level with the help of a robotics company that has already provided to the study of the components and has already budgeted also a possible industrialization of the process.
We have already contacted the other two manufacturers to have some alternative offers before to start comparative assessments and then proceed with the order.
The dimensioning of the system was made on the basis of the dismantling of about 45 panels/hour, corresponding to a weight of 1000 kg/hour, and such as to allow a power supply to the next step on the basis of a feed rate of about 2 cm/second.
2nd step Detachment of glass by sandwich (ACTION B3)
This action, which was the crux of the whole project, is now settled in brilliantly through the creation of a pre-prototype capable of handling a range of panels equal to 25% of that provided in the pilot plant.
After a month of testing, changes, implementations, technological innovations, practice tests, has now reached a level of reliability that allows us to confirm that the correct choice of the pre-prototype design object.
In June, it was also proven automation, which still needs fine-tuning, especially in relation to the variability of the panels to be treated, because, for the moment, we are limited to three types of the 18 considered by SSV phase characterization.
In any case we will also dedicate the month of July to complete the tests on all types available in order to evaluate each type of variable to which you may suffer.
In summary, the technology used is based on three innovations:
1 – Heating differentiated on the two sides of the sandwich (glass side and side wafer) with three different heating devices which ensure a delta of 20-30 degrees in temperature between the glass side and the side of the wafer. This delta is essential to ensure a perfect separation of the glass from the surface of EVA in contact with the glass itself.
2 – Mechanical Detachment of the glass by means of a pulsating knife, leveled at a fixed distance from the intrados side of the glass, result of an experiment on the field, which has allowed to minimize the effort of dragging of the panel and to maintain a perfect alignment of the detachment line with tolerances on the order of 0,1 mm. Both the oscillation that the amplitude of the pulsating movement are adjustable in an automatic way, depending on the characteristics of the panel.
3 – Complete automation of the progress of the panel as a function of 5 parameters:
- frequency of the pulsations of the knife;
- temperature in the transport section;
- temperature in the cutting section;
- thickness of the glass;
- typology of the backsheet.
Based on a few hours of steady state operation it can be said that the specific total energy used throughout the separation phase is well below the 100 kWh/t, provided as an objective in the presentation of the project.
In July, we will test the prototype also the gluing device in continuous of the panels to be treated, in order to evaluate also any problems due to the discontinuity in the longitudinal phase of contact with the pulsating knife.
3rd step Pyrolysis (ACTION B4)
There have been several tests of pyrolysis, for now in ambient not inertized with nitrogen to problems of delay in delivery of the equipment.
This, however, has served to complement the quantitative and qualitative data on the size of the silicon wafer, and this has already allowed you to change almost on a final mass flow.
It was also verified the ease of extracting, by simple sieving, after the pyrolysis, the strings of aluminum, inside of the ashes of pyrolysis, maintain dimensions significantly larger than the rest of the ashes.
The B3 action on the pyrolysis, whose term was scheduled to end in June 2014, will be completed by September, 2014, due to the delay in the receipt of laboratory equipment and the delay in obtaining the silicon wafer recovered through the operation of the pre-prototype.
4th step Leaching, Nanofiltration, Pyrolysis (ACTION B5)
The leaching has been studied only in the context of the possible reactive in particular on the need to send anything but the silicon in solution, and not to affect the nano silver particles which should be removed for nanofiltration before or after electrolysis. The type of electrolysis will be chosen based on the results of the nanofiltration.
These experiments will be the subject of thorough investigations and laboratory tests in the coming months. The action B5 will be completed by September 2014.
The project, passed the hurdle of detachment of the glass from sandwich, proceeds according to the programs, with a delay of three months on the actions B4 and B5.
Currently there aren’t obstacles in the way of good continuation.