Honeycomb filter bodies and particulate filters comprising honeycomb filter bodies
A honeycomb filter body comprises: a clean filter pressure drop of (P 1 ) and a clean filtration efficiency of (FE 1 ); a porous ceramic honeycomb body comprising a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels, the porous ceramic honeycomb body comprising a base clean filter pressure drop (P 0 ) and a base clean filtration efficiency (FE 0 ); and a porous inorganic layer disposed on one or more of the wall surfaces of the porous ceramic honeycomb body.
1. A honeycomb filter body comprising:
a porous ceramic honeycomb body comprising a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels extending between the first end and the second end of the honeycomb body including one or more plugged channels, wherein the plurality of walls have an average thickness between 25 μm and 250 μm, the walls having a base wall portion comprised of a bulk portion having a bulk mean pore size of between 7 μm and 25 μm and a bulk porosity of between 50% and 70%, and wherein the porous ceramic honeycomb body has a base clean filter pressure drop (P 0 ) and a base clean filtration efficiency (FE 0 ); and
a porous inorganic layer disposed on one or more of the wall surfaces of the porous ceramic honeycomb body, wherein the porous inorganic layer has an average porosity (ε) greater than or equal to 50%, a mean particle size (d p ) less than or equal to 2 μm, and a thickness (t m ) between 0.5 μm and 30 μm;
wherein the honeycomb filter body has a clean filter pressure drop (P 1 ) and a clean filtration efficiency of (FE 1 );
wherein an overall performance parameter of the honeycomb filter body has an overall performance parameter defined as “X”, which according to Formula (I):
(
FE
1
-
FE
0
)
*
P
0
(
P
1
-
P
0
)
*
FE
0
Formula
(
I
)
where FE 1 and FE 0 are mass based filtration efficiency parameters;
wherein the honeycomb filter body has a filtration performance defined as “F”, which is according to Formula (II):
FE
1
-
FE
0
FE
0
;
Formula
(
II
)
and
wherein X is greater than or equal to 1.75, and F is greater than or equal to 0.25.
2. The honeycomb filter body of claim 1 , wherein X is greater than or equal to 2.
3. The honeycomb filter body of claim 1 , wherein F is greater than or equal to 0.5.
4. The honeycomb filter body of claim 1 , wherein F is greater than or equal to 1.25.
5. The honeycomb filter body of claim 1 , wherein an axial distance of the honeycomb filter body spans from a first end to a second end of the honeycomb filter body, and the porous inorganic layer covers greater than or equal to 70% of the axial distance.
6. The honeycomb filter body of claim 5 , wherein the porous inorganic layer covers greater than or equal to 80% of the axial distance.
7. The honeycomb filter body of claim 5 , wherein the porous inorganic layer covers greater than or equal to 90% of the axial distance.
8. A honeycomb filter body comprising:
a porous ceramic honeycomb body comprising a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels;
a porous inorganic layer disposed on one or more of the wall surfaces of the porous ceramic honeycomb body, wherein the porous inorganic layer has an average porosity (ε) greater than or equal to 95%, a mean particle size (d p ) in micrometers, and a thickness t m ;
wherein a morphology parameter of the porous inorganic layer is defined as “Y”, which is according to Formula (IV):
(
ε
6.5
/
d
p
0.5
)
*
(
1
-
ε
d
p
0.5
)
;
Formula
(
IV
)
and
Y is greater than or equal to 0.02.
9. The honeycomb filter body of claim 8 , wherein Y is greater than or equal to 0.03.
10. The honeycomb filter body of claim 8 , wherein Y is greater than or equal to 0.05.
11. The honeycomb filter body of claim 8 , wherein the porous inorganic layer comprises a mean particle size (d p ) of less than or equal to 2 micrometers.
12. The honeycomb filter body of claim 11 , wherein the mean particle size (d p ) is less than or equal to 1 micrometer.
13. The honeycomb filter body of claim 11 , wherein the mean particle size (d p ) is less than or equal to 0.4 micrometers.
14. The honeycomb filter body of claim 8 further comprising a pressure drop performance is defined as “P”, which is according to Formula (III):
P
1
-
P
0
P
0
;
Formula
(
III
)
and
P is less than or equal to 0.25.
15. The honeycomb filter body of claim 14 , wherein P is less than or equal to 0.20.
16. The honeycomb filter body of claim 14 , wherein P is less than or equal to 0.05.
17. The honeycomb filter body of claim 8 , wherein a thickness (t m ) of the porous inorganic layer is in the range of greater than or equal to 0.5 micrometers to less than or equal to 30 micrometers.
18. The honeycomb filter body of claim 8 , comprising a plurality of plugged ends.