Wet Pulping System and Method for Producing Cellulosic Insulation with Low Ash Content

• US 20070137805A1
• Filed: 12/14/2006
• Published: 06/21/2007
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Fiberight LLC
• Original Assignee: Atlantic Recycling Technologies LLC
• Inventors: Stuart-Paul, Craig, Gerber, Steven, Gerber, Milton, Oganesoff, Eric
• Granted Patent: US 7,758,719 B2
• Time in Patent Office: Days
• US Class Current: 162/4
• CPC Class Codes: A01K 1/0152 Litter
• CPC Class Codes: A01K 1/0155 comprising organic material
• CPC Class Codes: D21B 1/026 Separating fibrous materials from waste
• CPC Class Codes: D21B 1/16 in the presence of chemical agents
• CPC Class Codes: D21B 1/32 of waste paper
• CPC Class Codes: D21C 11/00 Regeneration of pulp liquors or effluent waste waters
• CPC Class Codes: D21C 5/02 Working-up waste paper mechanical part D21B1/08, D21B1/32
• CPC Class Codes: Y02W 30/64 Paper recycling
• CPC Class Codes: Y10S 210/928 Paper mill waste, e.g. white water, black liquor treated

Abstract

Apparatus and method for recovering organic cellulosic fibers from landfill materials (such as post consumer, municipal and industrial waste materials). The apparatus and method selectively introduces waste materials containing organic cellulosic fibers into a size reduction machine. The pre-cleaned waste materials are conveyed to a tank, drum, or tunnel type fiber recovery apparatus. The waste materials are subjected to mechanical and fluid fiberization for a selected period of time to produce useful products, such as cellulosic insulation with a total ash content equal to or less than 10%, as well animal and fowl bedding products that is substantially devoid of moisture content, among other products.

Claims

1. A process for recovering organic cellulosic fibers from landfill materials such as post consumer, municipal and industrial waste materials comprising:

a. selectively introducing waste materials containing organic cellulosic fibers into a size reduction machine;

b. conveying such pre-cleaned waste material to a tank, drum or tunnel type fiber recovery apparatus; and

c. subjecting such waste material for a selected period of time to mechanical and fluid fiberization.

2. The process of claim 1 further comprising:

d. introducing a pulping fluid containing chemicals to enhance the fiber separation process;

e. selectively treating the recovered fibers with rapidly penetrating flame retardants, insecticidal properties and decay inhibitors;

f. selectively dyeing the separated fibers to selected colors; and

,

g. providing solids separation reagents to selectively remove contaminants in the pulping fluids.

3. The process of claim 1 where the pulping fluid is selectively heated to a temperature range between about 50°

F. to about 200°

F.

4. The process of claim 1 further comprising:

h. cleaning the recovered fibers through screening and hydro-cleaning devices to remove plastics and tramp metal;

i. conveying the removed plastics and tramp metals to a waste disposal system consisting of a receiving tank and a sludge press; and

j. extracting a high percentage of the pulping fluid for further processing.

5. The process of claim 1 further comprising:

k. subjecting the recovered fibers to a mechanical disk refiner to control fiber length, fiber bundle separation and fiber surface properties.

6. The process of claim 1 further comprising:

l. removing contaminants consisting of fillers, fines, coatings and other extraneous materials through the use of one or more clarifiers with select solids separation reagents and polymers.

7. The process of claim 1 further comprising:

m. extracting pulping fluids and water from the recovered fibers to formulate a cellulosic fiber wet lap of about 40% to about 60% pulp solids content;

n. fluffing the cellulosic fiber wet lap in a cake fluffer and a disk refiner;

o. drying the fluffed fibers in a flash or tunnel dryer; and

p. conveying the dried fibers to a packaging or baling system.

8. The process according to claim 7, wherein the step of drying comprises:

drying the fluffed fibers at a temperature from about 150 F to about 700°

F., thereby reducing bacteria content of the recovered fibers, and drying them to a uniform moisture content.

9. The process according to claim 8, wherein the moisture content is between about 10% and about 18%.

10. The process according to claim 8, wherein the dried fibers have a bulk density of between about 2 pounds per cubic foot to about 6 pounds per cubic foot.

11. The process according to claim 8, wherein the dried fibers are used for animal and fowl bedding and have a higher degree of absorbency than sawdust, straw, wood shaving, or conventional paper-based bedding.

12. The process according to claim 11, wherein the dried fibers used for animal and fowl bedding are about six times more absorbent than sawdust, straw or wood shavings.

13. The process according to claim 11, wherein the dried fibers used for animal and fowl bedding are between about 18 percent and 25 percent more absorbent than conventional paper-based bedding.

14. The process according to claim 8, wherein the dried fibers are used for animal and fowl bedding and incur between about 40% to about 50% less compaction than conventional paper-based animal and fowl bedding.

15. The process of claim 7, further comprising:

q. removing inorganic precipitated chemicals and contaminants from the extracted pulping fluids; and

r. recycling the pulping fluids back to the primary tank/drum/tunnel fiber recovery apparatus.

16. The process of claim 15 where the removed inorganic precipitated chemicals and selected contaminants comprise calcium hydroxide, calcium carbonate calcites, aluminum hydroxide, aluminum oxide, magnesium hydroxide and/or various other minor hydroxides.

17. The process according to claim 1, wherein the recovered organic cellulosic fibers comprise a final total ash content equal to or less than about 10%.

18. The process according to claim 1, wherein the recovered organic cellulosic fibers comprise a final total ash content of about 8.09%.

19. The process according to claim 1, wherein the recovered organic cellulosic fibers comprise an average fiber length greater than about 0.700 mm.

20. The process according to claim 1, wherein the recovered organic cellulosic fibers comprise an average fiber length of about 0.780 mm.

21. A cellulosic insulating fiber product that is used for thermal insulation in applications ranging from about −

50°

F. to about +170°

F., wherein

the composition of the fiber product has a bulk density of about 1.0 pounds per cubic foot to about 1.6 pounds per cubic foot,

the composition of the fiber product is substantially free of dust particles, and wherein

the composition of the fiber product has a final total ash content equal to or less than about 10%.

22. The cellulosic insulating fiber product according to claim 21, wherein the final total ash content is less than about 9%.

23. The cellulosic insulating fiber product according to claim 21, wherein the final total ash content is about 8.09%.

24. The cellulosic insulating fiber product according to claim 21, wherein the fiber product is selectively dyed to provide brand identification.

25. The cellulosic insulating fiber product according to claim 21, wherein the fiber product is used as acoustical insulation, packaging materials, industrial thickeners or fillers to be combined with other products, hydro-mulch and other related uses.

26. A cellulosic animal and fowl bedding fiber product that is used for the absorption of excess moisture, fecal matter and thermal insulation in animal applications, wherein

the composition of the cellulosic animal and fowl bedding fiber product has a bulk density of about 2.0 pounds per cubic foot to about 6.0 pounds per cubic foot,

the composition of the cellulosic animal and fowl bedding fiber product is substantially free of dust particles,

and wherein

the composition of the cellulosic animal and fowl bedding fiber product has a final total ash content equal to or less than about 10%.

27. The cellulosic animal and fowl bedding fiber product according to claim 26, wherein the ash content is less than about 9%.

28. The cellulosic animal and fowl bedding fiber product according to claim 26, wherein the ash content is about 8.09%.

29. The cellulosic animal and fowl bedding fiber product according to claim 26, wherein the fiber product is selectively dyed to provide brand identification.

30. The cellulosic animal and fowl bedding fiber product according to claim 26, wherein the fiber product has a higher absorbency than wood shavings, sawdust or straw and conventional paper-based litter.

31. The cellulosic animal and fowl bedding fiber product according to claims 26, wherein the fiber product reduces foot sores in poultry products in comparison to wood based bedding.

32. The cellulosic animal and fowl bedding fiber product according to claim 26, wherein the dried fibers are used for animal and fowl bedding and incur between about 40% to about 50% less compaction than conventional paper-based animal and fowl bedding.

33. A system for recovering organic cellulosic fibers from landfill materials such as post consumer, municipal and industrial waste materials comprising:

a. means for selectively introducing waste materials containing organic cellulosic fibers into a size reduction machine;

b. means for conveying such pre-cleaned waste material to a tank, drum or tunnel type fiber recovery apparatus; and

c. means for subjecting such waste material for a selected period of time to mechanical and fluid fiberization.

34. The system of claim 33 further comprising:

d. means for introducing a pulping fluid containing chemicals to enhance the fiber separation process;

e. means for selectively treating the recovered fibers with rapidly penetrating flame retardants, insecticidal properties and decay inhibitors;

f. means for selectively dyeing the separated fibers to selected colors; and

,

g. means for providing solids separation reagents to selectively remove contaminants in the pulping fluids.

35. The system of claim 33 where the pulping fluid is selectively heated to a temperature range between about 100°

F. to about 200°

F.

36. The system of claim 33 further comprising:

h. means for cleaning the recovered fibers through screening and hydro-cleaning devices to remove plastics and tramp metal;

i. means for conveying the removed plastics and tramp metals to a waste disposal system consisting of a receiving tank and a sludge press; and

j. means for extracting a high percentage of the pulping fluid for further processing.

37. The system of claim 33 further comprising:

k. means for subjecting the recovered fibers to a mechanical disk refiner to control fiber length, fiber bundle separation and fiber surface properties.

38. The system of claim 33 further comprising:

l. means for removing contaminants consisting of fillers, fines, coatings and other extraneous materials through the use of one or more clarifiers with select solids separation reagents and polymers.

39. The system of claim 33 further comprising:

m. means for extracting pulping fluids and water from the recovered fibers to formulate a cellulosic fiber wet lap of about 40% to about 60% pulp solids content;

n. means for fluffing the cellulosic fiber wet lap in a cake fluffer and a disk refiner;

o. means for drying the fluffed fibers in a flash and/or tunnel dryer; and

p. means for conveying the dried fibers to a packaging or baling system.

40. The system according to claim 39, wherein the means for drying comprises:

drying the fluffed fibers at a temperature between about 150°

F. and about 700°

F., thereby reducing bacteria in the fluffed recovered fibers, and drying them to a uniform moisture content.

41. The system according to claim 39, wherein the means for drying comprises drying the fluffed fibers at a temperature above about 300°

F., thereby reducing bacteria in the fluffed recovered fibers, and drying them to a uniform moisture content.

42. The system according to claim 41, wherein the moisture content is between about 10% and about 18%.

43. The system of claim 39, further comprising:

q. means for removing inorganic precipitated chemicals and contaminants from the extracted pulping fluids; and

r. means for recycling the pulping fluids back to the primary tank/drum/tunnel fiber recovery apparatus.

44. The system of claim 43 where the removed inorganic precipitated chemicals and selected contaminants comprise calcium hydroxide, calcium carbonate calcites, aluminum hydroxide, aluminum oxide, magnesium hydroxide and/or various other minor hydroxides.

45. The system according to claim 33, wherein the recovered organic cellulosic fibers comprise a final total ash content equal to or less than about 10%.

46. The system according to claim 33, wherein the recovered organic cellulosic fibers comprise an average fiber length greater than about 0.700 mm.

47. The system according to claim 33, wherein the recovered organic cellulosic fibers comprise an average fiber length greater than about 0.780 mm.

48. A method for recovering cellulosic fibers from mixed trash comprising:

a. loading waste containing cellulosic fibers and other non-organic materials into a sorting apparatus to produce a combination of short and long fiber feedstock;

b. blending the sorted trash to maintain ratio of about 50% to about 90% short fiber feedstock and about 10% to about 50% long fiber feedstock;

c. shredding the blended sorted fiber feedstock;

d. weighing the shredded fiber feedstock into load sizes of about 100 to about 300 lbs;

e. pulping the weighed fiber feedstock into cellulosic fibers and a first through fourth group of select waste materials with pulping fluids in a fiber extractor recovery apparatus thereby impregnating the cellulosic fibers with the pulping fluids;

f. draining the cellulosic fibers from the extractor fiber recovery apparatus into a hydro-cleaner;

g. de-watering the impregnated cellulosic fibers in the hydro-cleaner to reduce the amount of pulping fluid in the impregnated cellulosic fibers, and extracting a portion of the second group of select waste materials;

h. depositing the extracted portion of second group of select waste materials into a landfill;

i. fluffing the de-watered cellulosic fibers in a first disk refiner;

j. thickening the fluffed cellulosic fibers in a thickener and extracting pulping fluid for re-use in the fiber extractor recovery apparatus;

k. storing the thickened cellulosic fibers in a stock chest apparatus;

l. extracting pulping fluid from the thickened cellulosic fibers in a pulping fluid extractor;

m. impregnating additional chemicals comprising fire retardant chemicals, dyes, insecticides, and/or biocides, such that the final cellulosic fiber product comprises a flame retardant loading of about 6%;

n. extracting excess pulping fluid from the thickened cellulosic fibers in a pulp press thereby producing partially dried thickened cellulosic fibers;

o. fluffing the partially dried thickened cellulosic fibers in a fluffer apparatus that reduces a density of the cellulosic fibers from a first range of about 6 to about 10 lbs per cubic foot to a second density range from about 2 to about 6 lbs per cubic foot, with a post fluffing moisture content of about 40% to about 60%;

p. additionally fluffing the cellulosic fibers in a second disk refiner at a temperature between about 150°

F. and about 700°

F.;

q. drying the cellulosic fibers in a dryer to further reduce the moisture content to about 10% to about 18%; and

s. packaging and/or baling the dried cellulosic fibers.

49. The method according to claim 48, wherein the step of pulping comprises:

i. rotating and agitating the shredded fiber feedstock in a plurality of fiber recovery apparatuses into cellulosic fibers and first through fourth groups of select waste materials, each of the fiber recovery apparatuses containing pulping fluid, wherein the pulping fluid comprises a combination of water, fire retardant chemicals, biocides, dyes, insecticides and surfactants;

ii. impregnating the cellulosic fibers and the first through fourth select waste materials with fire resistant chemicals, dyes, chemical insecticides, and/or biocides;

iii. separating the impregnated cellulosic fibers from the first group of select waste materials that are not utilized or desired in separator fiber recovery apparatuses;

iv. extracting the first group of select waste materials dissolved within the pulping fluid from the cellulosic fibers in a dirty water tank, DAF contaminant separator, waste tank, sludge press and then depositing the first group of select waste materials into a landfill;

v. separating the impregnated cellulosic fibers from the second group of select waste materials in an extractor fiber recovery apparatus; and

vi. extracting the second group of select waste materials from the impregnated cellulosic fibers.

50. The method according to claim 49, further comprising:

t. transferring pulping fluid extracted from the pulping fluid extractor and pulp press to a dirty water storage chest to extract additional inorganic compounds such as calcium carbonate, aluminum and magnesium hydroxide;

u. adding one or more acids to the water and pulping fluid stored in the dirty water storage chest to lower the pH of the pulping fluid to a range of about 4.0 to about 5.0;

v. mixing the pulping fluids in a first precipitator with one or more alkaline agents to increase the pH of the pulping fluid to a range of about 4.5 to about 6.0 to cause precipitation of aluminum and magnesium hydroxide byproducts;

w. centrifuging the mixture of pulping fluids and precipitated aluminum and magnesium hydroxide byproducts in a first centrifuge to separate and discard the aluminum and magnesium hydroxide byproducts;

x. adding carbon dioxide to the first centrifuged pulping fluids;

y. mixing the pulping fluids in a second precipitator with one or more additional alkaline agents to increase the pH of the carbonated pulping fluids to a range of about 11.5 to about 12.8 or to a pH point wherein calcium carbonate precipitates from the carbonated pulping fluids;

z. centrifuging the mixture of carbonated pulping fluids and precipitated calcium carbonate byproducts in a second centrifuge to separate and discard the calcium carbonate byproducts, thereby producing treated white water for use in the recovery process; and

aa. storing the treated white water in storage tanks for use in the recover process and apparatus.

51. The method according to claim 49, wherein the step of additionally fluffing the cellulosic fibers in a second disk refiner is omitted, and the step of drying includes drying the cellulosic fibers at a temperature between about 250°

f. and 350°

F., thereby producing animal and fowl bedding product.

52. A system for recovering organic cellulosic fibers from landfill materials comprising:

a. a stock preparation apparatus configured to prepare a suitable combination of short fiber and long fiber feedstock for use in the cellulosic fiber recovery system from landfill materials and further configured to mix the short fiber and long fiber feedstock with a pulping fluid thereby initially separating the short fibers and long fibers from first through fourth groups of select waste materials, and to further process the first group of select waste materials;

b. a stock extraction apparatus configured to further mix the separated short and long fiber feedstock with the pulping fluid, and to extract a second group of select waste materials thereby producing a thickened slurry of cellulosic fibers from the combination of short and long fiber feedstock that is substantially free from the second group of select waste materials; and

c. a pulp drying and packaging apparatus configured to extract pulping fluid from the thickened slurry of cellulosic fibers, and which is further configured to separate third and fourth groups of select waste materials from the pulping fluid and to fluff, dry, and bale the thickened slurry of cellulosic fibers as recovered organic cellulosic fibers with a moisture content of about 10% to about 18%.

53. The system according to claim 52, wherein the first group of select waste materials comprises fillers, coatings, fines, clays, among other non-organic materials.

54. The system according to claim 52, wherein the second group of select waste materials comprises plastics, metals, glass, among others.

55. The system according to claim 52, wherein the third group of select waste materials comprises calcium carbonate, among others.

56. The system according to claim 52, wherein the fourth group of select waste materials comprises aluminum and magnesium hydroxides, among others.

57. The system according to claim 52, wherein the stock preparation apparatus comprises:

a. a trash sorting apparatus configured to sort gross trash into a first group of trash comprising cellulosic fibers, and a second group of trash that is substantially free of cellulosic fibers;

b. a fiber blending apparatus configured to selectively and mechanically blend the first group of trash comprising cellulosic fibers such that a ratio of about 50% to about 90% of short cellulosic fibers and about 10% to about 90% long cellulosic fibers is maintained in the recovery system;

c. a shredder apparatus configured to continuously shred the selectively maintained short and long cellulosic fibers into smaller pieces;

d. a weigh feeder configured to continuously measure the shredded short and long cellulosic fibers into substantially equivalent loads of about 100 lbs to about 300 lbs per load;

e. one or more drums/tunnel pulpers configured to substantially continuously mix pulping fluids with the shredded short and long cellulosic fibers such that separation of short and long cellulosic fibers from first through fourth groups of select waste materials occurs, and treatment of the short and long cellulosic fibers with the pulping fluid occurs; and

f. a chemical dissolver configured to produce the pulping fluids from a combination of water, and rapidly penetrating surfactants, dyes, insecticides, biocides, and/or flame retardants.

58. The system according to claim 57, wherein

the short cellulosic fiber comprises fibers of a first length from about 0.5 mm to about 0.7 mm, and

the long cellulosic fiber comprises fibers of a second length from about 0.7 mm to about 0.9 mm.

59. The system according to claim 57, wherein

the one or more drums/tunnels are further configured to rotate at substantially equal intervals, and

then reverse rotation for a second interval, in the case there are more than one drum/tunnel, in order to transfer the mixture of pulping fluids and shredded short and long cellulosic fibers from a first to a subsequent drum/tunnel, and from the subsequent drum/tunnel to additional subsequent drum/tunnels should there be such additional subsequent drum/tunnels;

and

wherein the one or more drum/tunnels are further configured to transfer the mixture of pulping fluids, shredded short and long cellulosic fibers into an additional processing stage during the reverse rotation interval.

60. The system according to claim 57, wherein the fire retardants comprise those fire retardants that when absorbed by the short and long cellulosic fibers meet federal requirements STM C-739, C-1149, C-1497, and CPSC 16 C.F.R. §

§

208, 1404.

61. The system according to claim 52, wherein the stock extraction apparatus comprises:

i. one or more additional drums/tunnel pulpers configured to further substantially continuously mix pulping fluids with the shredded short and long cellulosic fibers such that

separation of short and long cellulosic fibers further occurs from a first and second group of select waste material, and

continuous treatment of the short and long cellulosic fibers with the pulping fluid occurs producing a cellulosic fiber slurry, and

further wherein the second group of select waste materials is removed from the one or more additional drums/tunnel pulpers, and

further wherein the cellulosic fiber slurry is also transferred out of the one or more additional drums/tunnel pulpers;

ii. an extractor configured to hold the transferred cellulosic fiber slurry;

iii. a hydrocleaner configured to extract still additional second group of select waste materials from the cellulosic fiber slurry;

iv. a disk refiner configured to fluff the cellulosic fiber slurry;

v. a thickener configured to remove water and/or additional liquids from the fluffed cellulosic fiber slurry such that the percentage of cellulosic fibers with the fluffed cellulosic fiber slurry increases from a first range of about 1.5% to about 2% to a second range of about 3.0% to about 4.5%; and

vi. a plurality of white water holding tanks configured to hold the water and other liquids removed by the thickener.

62. The system according to claim 52, wherein the pulp drying and packaging apparatus comprises:

i. a pulping fluid extractor configured to extract additional pulping fluid from the thickened cellulosic fiber slurry;

ii. an additional chemical dissolver tank to produce an optional fire retardant spray comprising fire retardant chemicals, dyes, insecticides and/or biocides, wherein the optional fire retardant spray can be applied to the thickened fiber cellulosic slurry;

iii. a pulp press configured to extract additional water and/or other liquids such that the thickened fiber cellulosic slurry is about 40% to about 60% solids, thereby producing cellulosic fiber wet lap;

iv. a fluffer configured to fluff the cellulosic fiber wet lap into a fluffed cellulosic fiber wet lap;

v. a disk refiner configured to additionally fluff the fluffed cellulosic fiber wet lap;

vi. a flash/tunnel dryer configured to dry the fluffed cellulosic fiber wet lap at a temperature between about 150°

F. and about 700°

F. thereby reducing a moisture content to a range of about 10% to about 18%; and

vii. a packaging or bailing apparatus configured to package or bail the substantially dry fluffed cellulosic fiber wet lap.

63. The system according to claim 52 further comprising:

d. a water treatment apparatus configured to recover pulping fluid at various points in the recovery process, separate the third and fourth group of select waste materials from the pulping fluid thereby creating treated white water which can then be returned to the recover system for continuous recovery of organic cellulosic fibers from landfill materials.

64. The system according to claim 63, wherein the water treatment apparatus comprises:

a. an acid supply tank configured to store a supply of one or more acids, comprising sulfuric acid, phosphoric acid, acidic acid, among others;

b. a dirty water storage tank configured to receive pulping fluids removed from the fluffed cellulosic fiber slurry by the thickener and further configured to add one or more of the acids stored in the acid supply tank such that a pH level of the pulping fluids is reduced to a range of about 4.0 to about 5.0 so as to dissolve one or more organic compounds comprising calcium carbonate, aluminum hydroxide, magnesium hydroxide, among others;

c. a first alkaline agent holding tank configured to store one or more agents comprising sodium tetraborate, sodium borates, calcium borates, ammonium hydroxide, anhydrous ammonia, lime, and/or soda ash, among others;

d. a first precipitator configured to the receive water and/or additional liquids from the dirty water storage tank, and further configured to add one or more of the agents stored in the first alkaline agent storage tank such that a pH level of the received pulping fluids is increased to a range of about 4.5 to about 6.0 so as to cause precipitation of aluminum and magnesium hydroxide byproducts;

e. a first centrifuge configured to received the pulping fluids from the first precipitator, and further configured to centrifuge the first precipitated pulping fluids to separate and collect the aluminum and magnesium hydroxide byproducts;

f. a carbonator configured to receive the pulping fluids from the first centrifuge, and further configured to add carbon dioxide to the pulping fluids;

g. a second alkaline agent holding tank configured to store one or more agents comprising sodium tetraborate, sodium borates, calcium borates, ammonium hydroxide, anhydrous ammonia, lime, and/or soda ash, among others;

h. a second precipitator configured to receive the pulping fluids from the carbonator, and further configured to add one or more of the agents stored in the second alkaline agent storage tank such that a pH level of the received pulping fluids is increased to a range of about 11.5 to about 12.0, or to such pH level so as to cause precipitation of calcium carbonate;

i. a second centrifuge configured to received the pulping fluids from the second precipitator, and further configured to centrifuge the second precipitated pulping fluids to separate and collect the calcium carbonate; and

j. a treated white water storage tank configured to store and transfer the treated white water now substantially free of calcium carbonate, and aluminum and magnesium hydroxide byproducts and which has a pH level in the range of about 11.5 to about 12.0.

65. The system according to claim 52, wherein the flash/tunnel dryer is configured to dry the fluffed cellulosic fiber wet lap at a temperature between about 250°

F. and about 350°

F.