Assembling the flow cell from components
- Mechanical assembly
- Using a torque wrench properly
Ensure you have the following components:
Parts
- 4 barbed fittings
- 2 blocking gaskets
- 2 cell bodies
- 3 cut membranes
- 2 flow frames
- 2 grafoil current collectors
- 4 M6 nuts
- 4 M6 x 60 mm hex socket cap bolts
- 4 o-rings
- 2 pass-through gaskets
- several cm polypropylene packing tape
Tools
- 1 10 mm socket - To fit torque wrench
- 1 5mm hex key
- 1 torque wrench - to accept 5 mm allen key or 10 mm hex socket
Here is an overview of assembling an outdated version of the cell:
Step 1: Attach the barbed fittings
Take the two cell bodies and place one o-ring at the bottom of each threaded hole.
Then insert and carefully hand-thread the barbed fittings to the bottom of the port.
Step 2: Insulate the bolts with packing tape
Wrap polypropylene packing tape around the shafts of the bolts, leaving the final 1 cm of threads exposed.
Note
This prevents accidental short circuits of the cell from the bolt shafts contacting the grafoil.
Step 3: Insert the four bolts into one cell body
Take one cell body and insert the four M6 x 60 mm hex socket cap bolts so that the socket caps are on the same side of the cell as the barbs.
Step 4: Add the first grafoil current collector
Take this same cell body and place one grafoil current collector on top of the copper plate.
Step 5: Add the first pass-through gasket
Place one pass-through gasket on top of the assembly, using the bolts to guide the gasket and align it with the fluid holes in the cell body.
Help Block
The total combined thickess of the flow frames and (compressed) gaskets is key to achieving the desired results! There are multiple thickness options in the flow-frames folder and custom thicknesses can be genererated from the FreeCAD files. The graphite felt should be compressed to 70% of it's original thickness. The compression is fixed by the combined total thickness of the flow frame and two gaskets.
Place one flow frame on top of the assembly, using the bolts to guide the flow frame and align it with the fluid holes in the gasket.
Step 6: Add the first blocking gasket
Place one blocking gasket on top of the assembly, using the bolts to guide the gasket and align it with the fluid holes in the flow frame.
Step 7: Add the membranes
Take the three cut membranes and add them to the assembly.
Step 8: Add the second blocking gasket
Place one blocking gasket on top of the assembly, using the bolts to guide the gasket.
Step 9: Add the second flow frame
Place one flow frame on top of the assembly, using the bolts to guide the flow frame.
Step 10: Add the second pass-through gasket
Place one pass-through gasket on top of the assembly, using the bolts to guide the gasket and align it with the fluid holes in the flow frame.
Step 11: Add the second grafoil current collector
Place one grafoil current collector on top of the pass-through gasket, so that it will align with the copper current collector of the second cell body in the next step.
Step 12: Add the second cell body
Place the second cell body (with barbs and copper plate installed) on top of the assembly and ensure all fluid holes are aligned. Hand-tighten four M6 nuts onto the exposed threads of the bolts in order to lightly compress the cell and hold all the components in place.
Step 13: Tighten the bolts
Progressively tighten the bolts to 5 N⋅m in a 4-bolt flange pattern using a torque wrench fitted with a 10 mm socket and a 5mm hex key
Note
Progressively tightening using a flange pattern is important to evenly compressing the cell and ensuring leak-free operation
Add the barbed fittings
Warning
Do not overtighten the barbed fittings, or else they can shear off inside of the cell body!
Add the o-rings to the bottom of the threaded cell ports. Insert the barbed fittings and thread to finger-tight, then turn with a wrench 90 degrees past finger-tight.
Now you have an assembled flow cell!