Duct optimization to prevent freezing
View Patent ↗In a device for conveying liquids or moist gases through a closed duct in a vehicle fuel cell power systems, freezing of the duct is prevented by providing a part of its internal wall flow passages or flow chambers with a nonwoven material. The nonwoven material absorbs liquid in disperse form at low temperatures through its capillary action and inhibits premature ice formation.
1. A device for the passage of liquids or moist gases, comprising:
a closed duct; and
a nonwoven fabric which is disposed at least in part on an internal wall of flow passages or flow chambers of said duct, and has a mesh structure which absorbs liquid in disperse form at low temperatures.
2. A device for the passage of liquids or moist gases, comprising:
a closed duct; and
a nonwoven fabric which is disposed at least in part on internal wall flow passages or flow chambers of said duct, and which absorbs liquid in disperse form at low temperatures;
wherein the nonwoven material is of multi-ply construction.
3. The device as claimed in claim 2 , wherein the nonwoven is made of stainless steel.
4. The device as claimed in claim 2 , wherein:
at least one ply of the nonwoven material has a coarse mesh structure and performs a supporting function; and
at least one ply of the nonwoven material has a fine mesh structure and performs a capillary action.
5. The device as claimed in claim 4 , wherein:
the ply with a coarse mesh structure is directed towards the wall-side duct surface; and
the ply with a fine mesh structure is directed towards the middle of the duct.
6. The device as claimed in claim 4 , wherein the nonwoven ply with a fine mesh structure has a coating that prevents condensate formation.
7. The device as claimed in claim 6 , wherein the coating on the fine mesh structure comprises aluminum silicate.
8. The device as claimed in claim 6 , wherein the coating on the fine mesh structure comprises a polymer with acid or alkali residues.
9. A device for the passage of liquids or moist gases, comprising:
a closed duct;
a nonwoven material which is disposed at least in part on internal wall flow passages or flow chambers of said duct, and which absorbs liquid in disperse form at low temperatures; and
an element for heating the nonwoven material at least in places.
10. The device as claimed in claim 9 , wherein the nonwoven ply with a coarse, supporting mesh structure is constructed at least in places as a heating conductor.
11. A method of installing a nonwoven material into a closed duct for conveying a fluid flow, said method comprising:
inserting the nonwoven material in a rolled-up state into the closed duct; and
unrolling the nonwoven material when it is located at a point necessary for functioning to absorb liquid in disperse form at low temperatures within the closed duct.