Deep gradient-density filter device

1. A deep gradient-density filter device having a depth of at least approximately 0.5 inch (1.27 cm.) and capable of filtering a fluid containing a distribution of particles in the range of approximately 25 microns to approximately 0.2 micron, the deep gradient-density filter device comprising in order:

(a) a pre-filtration zone comprising layers of filtration material, said pre-filtration zone capable of retaining particles in the range of approximately 25 microns to approximately 1 micron,

(b) a primary filtration zone comprising filtration material, said primary filtration zone capable retaining particles in the range of approximately 1 micron to approximately 0.3 micron, and

(c) a polishing zone comprising layers of filtration material, said polishing zone capable of retaining particles in the range of approximately 0.3 micron to approximately 0.2 micron; and

wherein the retention capabilities of the pre-filtration zone, the primary filtration zone, and the polishing zone, as recited in (a), (b), and (c) respectively, are established at a fluid velocity of at least approximately 100 cm/hr and an initial hydraulic permeability of greater than approximately 10 cm/hr/psi.

2. The deep gradient-density filter device of claim 1 , wherein said primary filtration zone comprises at least one layer of fibrillated fiber containing material.

3. The deep gradient-density filter device of claim 1 , wherein said pre-filtration zone comprises:

(i) a layer of non-woven fiber material having an approximately 25 micron nominal pore rating; and

(ii) a layer of non-woven fiber material having an approximately 1 micron nominal pore rating.

4. The deep gradient-density filter device of claim 3 , wherein said layers (i) and (ii) of said primary filtration zone are both substantially made of propylene fiber material, and both have a thickness within the range of approximately 0.10 inch (0.254 cm.) to approximately 0.15 inch (0.381 cm).

5. The deep gradient-density filter device of claim 3 , wherein said primary filtration zone comprises at least one layer of fibrillated fiber containing material.

6. The deep gradient-density filter device of claim 5 , wherein said polishing zone comprises:

(i) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 140 to approximately 260 LMH/psi;

(ii) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 68 to approximately 120 LMH/psi;

(iii) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 300 to approximately 560 LMH/psi;

(iv) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 140 to approximately 260 LMH/psi; and

(v) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 70 to approximately 120 LMH/psi.

7. The deep gradient-density filter device of claim 6 , wherein said layers (i), (ii), (iii), (iv), and (v) of said polishing zone each have a thickness within the range of approximately 0.10 inch (0.254 cm.) to approximately 0.15 inch (0.381 cm).

8. A biopharmaceutical fluid processing methodology comprising the steps of:

providing a manufactured protein-containing solution comprising a synthetically-enriched concentration of a predetermined target protein and a distribution of solid particles of differing sizes;

providing a deep gradient-density filter device comprising abutting layers of filtration materials that collectively have a depth of at least approximately a half-inch; and

passing said manufactured protein-containing solution through said deep gradient-density filter device at a velocity of at least approximately 100 cm/hr.

9. The biopharmaceutical fluid processing methodology of claim 8 ,

wherein said abutting layers of filtration material of said deep gradient-density filter device define a pre-filtration zone, and primary filtration zone, and a polishing zone;

wherein said pre-filtration zone is capable of retaining particles in the range of approximately 25 microns to approximately 1 micron, said primary filtration zone is capable retaining particles in the range of approximately 1 micron to approximately 0.3 micron, and said polishing zone is capable of retaining particles in the range of approximately 0.3 micron to approximately 0.2 micron; and

wherein the retention capabilities of the pre-filtration zone, the primary filtration zone, and the polishing zone are established at a fluid velocity of at least approximately 100 cm/hr and an initial hydraulic permeability of greater than approximately 10 cm/hr/psi.

10. The biopharmaceutical fluid processing methodology of claim 8 ,

wherein said abutting layers of filtration material of said deep gradient-density filter device define a pre-filtration zone, and primary filtration zone, and a polishing zone; and

wherein said pre-filtration zone is capable of retaining particles within a first size distribution range; said primary filtration zone comprises at least one layer of fibrillated fiber containing material and is capable of retaining particles within a second size distribution range smaller than said first size distribution range, and said polishing zone is capable of retaining particles within a third size distribution range smaller than said second size distribution range.

11. A deep gradient-density filter device comprising in order:

a pre-filtration zone comprising layers of filtration material, said pre-filtration zone capable of retaining particles within a first size distribution range;

a primary filtration zone comprising at least one layer of fibrillated fiber containing material, said primary filtration zone capable of retaining particles within a second size distribution range, said second size distribution range being smaller than said first size distribution range; and

a polishing zone comprising layers of filtration material, said polishing zone capable of retaining particles within a third size distribution range, said third size distribution range being smaller than said second size distribution range.

12. The deep gradient-density filter device of claim 11 ,

wherein the device is capable of filtering a fluid containing a distribution of particles in the range of approximately 25 microns to approximately 0.2 micron; and

wherein said first size distribution range is approximately 25 microns to approximately 1 micron, said second size distribution range is approximately 1 micron to approximately 0.3 micron, and said third size distribution range is approximately 0.3 micron to approximately 0.2 micron; and

wherein the retention capabilities of the pre-filtration zone, the primary filtration zone, and the polishing zone are established at a fluid velocity of at least approximately 100 cm/hr and an initial hydraulic permeability of greater than approximately 10 cm/hr/psi.

13. The deep gradient-density filter device of claim 11 , wherein said pre-filtration zone comprises:

(i) a layer of non-woven fiber material having an approximately 25 micron nominal pore rating; and

(ii) a layer of non-woven fiber material having an approximately 1 micron nominal pore rating.

14. The deep gradient-density filter device of claim 13 , wherein said layers (i) and (ii) of said primary filtration zone are both substantially made of propylene fiber material.

15. The deep gradient-density filter device of claim 13 , wherein said polishing zone comprises:

(i) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 140 to approximately 260 LMH/psi;

(ii) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 68 to approximately 120 LMH/psi;

(iii) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 300 to approximately 560 LMH/psi;

(iv) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 140 to approximately 260 LMH/psi; and

(v) a wet-laid layer of cellulose and diatomaceous earth having a permeability of approximately 70 to approximately 120 LMH/psi.