This passive gravity valve is made for the discharge outlet of a screw conveyor with a DN250 / 10inch outlet. Primarily, the valve is needed to stop the uninterrupted ingress of air into the conveyor and consequently into the pyrolysis process of which it is a part of. In order for a pyrolysis process to operate effectively there must be little or no air present. This passive gravity valve offers a quick to implement solution that can be made entirely on site with nothing more than a 3D printer, some nuts, bolts and washers. While it doesn’t completely eliminate air ingress, it greatly reduces the air flow into the system, thereby improving the process’s effectiveness. The valve is designed to operate passively. The weight of material accumulating on the inside of the flap triggers it to open, and once the material has been discharged, the valve closes. It has been designed to be 3D printed on a standard FDM 3D printer, with a print volume of 300mm by 300mm by 300mm. The entire assembly can be printed in a few working days if only one printer is available. Additional printers will speed up print time. This valve has been printed in ABS filament. Other filaments can be used. This post is an introductory post to the valve and I will follow up with printing and assembly instructions as well as updates on its performance in a live, large-scale pyrolysis system. See the rotating model below? It’s interactive – click on it to have a look!
Follow up posts will include:
- 3D printing information incl. print settings, times and material usage
- validation of air ingress reduction on a live pyrolysis process
- general design process
- 3D printing and assembly images
