dvontedlores
Member
Hello everyone, so this topic might get a bit complicated. I am currently designing/building/redesigning a system to cast palladium via induction for jewelry. To spare the details, I will try to summarize. This will have an argon atmosphere above the melt, a vacuum below the mold, and 15kw (7.5kw in reality) chinese induction heater. Currently attempting to melt a tiny 1g palladium ingot I bought online. At least in my current quantities I am not getting it hot enough. During one experiment I had a graphite crucible sitting on a concrete block and I managed to melt the concrete, but not the palladium. I have not found an affordable infrared thermometer that can reach above 3000°f and my current one only goes to 800. Concrete is supposed to melt at 2300ish F, and palladium 2800, so I know I am getting close lol. Since then, I have made lots of design changes. My graphite crucible (it will be lined eventually) slides down into a vacuum chamber which is insulated with ceramic insulation. The induction coil is inside the chamber.
The induction coil is causing issues. Too many loops and the machine cannot run it. Too few loops and it doesnt get hot enough. I have heard that the crucible can be slowly inserted and it will work because there is less resistance as it heats up, but due to the nature of this design, I dont think I can do that and it seems janky. I have seen references to parallel coil systems, but I have not found anyone that has done this. Essentially there is still two main lines in and out of the induction heater, but just before the coil, it splits into two lines per side. These run to top positive and bottom positive for one line and top negative and bottom negative for the other line. I know this terminology is incorrect but you get the idea. I fail to understand how this would benefit more than just a long coil, but I read that if you make your coil length too long for one coil, you need to split it up into two coils in parallel. Any thoughts? Has anyone successfully done this?
The induction coil is causing issues. Too many loops and the machine cannot run it. Too few loops and it doesnt get hot enough. I have heard that the crucible can be slowly inserted and it will work because there is less resistance as it heats up, but due to the nature of this design, I dont think I can do that and it seems janky. I have seen references to parallel coil systems, but I have not found anyone that has done this. Essentially there is still two main lines in and out of the induction heater, but just before the coil, it splits into two lines per side. These run to top positive and bottom positive for one line and top negative and bottom negative for the other line. I know this terminology is incorrect but you get the idea. I fail to understand how this would benefit more than just a long coil, but I read that if you make your coil length too long for one coil, you need to split it up into two coils in parallel. Any thoughts? Has anyone successfully done this?