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A process for making bleached pulp comprises contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency; bleaching the pulp mixture, to obtain a first bleached pulp m

A process for making bleached pulp comprises contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency; bleaching the pulp mixture, to obtain a first bleached pulp mixture; pressing or dewatering the bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate; sending a portion of the second filtrate to a second location of the first recycled filtrate loop, wherein the second location is downstream of and in fluid communication with the first location; contacting the pressed bleached pulp mixture with a second recycled filtrate obtained from a third location of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location is downstream of and in fluid communication with the second location; bleaching the second pulp mixture, to obtain a second bleached pulp mixture; pressing or dewatering the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate; sending a portion of the third filtrate to a fourth location of the first recycled filtrate loop, wherein the fourth location is downstream of and in fluid communication with the third location; and recycling a portion of the third filtrate in the first recycled filtrate loop to the first location.

대표청구항 ▼

1. A process for making bleached pulp, comprising: (a1) pressing a first unbleached pulp mixture to produce an unbleached pulp mixture and a first filtrate; and(a2) sending at least a portion of the first filtrate to a first location (2) of a second recycled filtrate loop;(a3) contacting the unbleac

1. A process for making bleached pulp, comprising: (a1) pressing a first unbleached pulp mixture to produce an unbleached pulp mixture and a first filtrate; and(a2) sending at least a portion of the first filtrate to a first location (2) of a second recycled filtrate loop;(a3) contacting the unbleached pulp mixture with a first recycled filtrate obtained from a first location (3) of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency;(b) bleaching the first pulp mixture, to obtain a first bleached pulp mixture;(c) pressing the first bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate;(d) sending at least a portion of the second filtrate to a second location (5) of the first recycled filtrate loop, wherein the second location (5) is downstream of and in fluid communication with the first location (3);(e) contacting the first pressed bleached pulp mixture with a second recycled filtrate obtained from a third location (6) of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location (6) is downstream of and in fluid communication with the second location (5);(f) bleaching the second pulp mixture, to obtain a second bleached pulp mixture;(g) pressing the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate;(h) sending at least a portion of the third filtrate to a fourth location (8) of the first recycled filtrate loop, wherein the fourth location (8) is downstream of and in fluid communication with the third location (6); and(i) recycling at least a portion of the third filtrate in the first recycled filtrate loop to the first location (3);to obtain the bleached pulp;wherein the second recycled filtrate loop is in fluid communication with the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof. 2. The process of claim 1, wherein the first recycled filtrate loop comprises a residual bleaching agent. 3. The process of claim 1, wherein the second recycled filtrate loop is free of residual bleaching agent. 4. The process of claim 1, wherein the first recycled filtrate loop contains a higher concentration of residual bleaching agent than does the second recycled filtrate loop. 5. The process of claim 1, further comprising diluting the first unbleached pulp mixture prior to pressing the first unbleached pulp mixture. 6. The process of claim 1, further comprising one or more of sending at least a portion of the first filtrate in the second recycled filtrate loop to an upsteam storage tank, sending at least a portion of the first filtrate in the second recycled filtrate loop upstream to dilute the first unbleached pulp mixture prior to dewatering the first unbleached pulp mixture. 7. The process of claim 1, further comprising diluting the first bleached pulp mixture. 8. The process of claim 1, further comprising contacting and diluting the first bleached pulp mixture with a recycled filtrate obtained from a location (4) of the first recycled filtrate loop, wherein location (4) is downstream of the first location (3) and upstream of the second location (5). 9. The process of claim 8, wherein the first bleached pulp mixture has a consistency of about 12% before the diluting. 10. The process of claim 1, further comprising diluting the second bleached pulp mixture. 11. The process of claim 1, wherein the second bleached pulp mixture has a consistency of about 30% before the diluting. 12. The process of claim 1, wherein the unbleached pulp mixture has a consistency of about 33-35%. 13. The process of claim 1, wherein the first pulp mixture has a first consistency of about 12%. 14. The process of claim 1, wherein the first pressed bleached pulp mixture has a consistency of about 33-35%. 15. The process of claim 1, wherein a second pulp mixture has a second consistency of about 30%. 16. The process of claim 1, wherein the second pressed bleached pulp mixture has a consistency of about 33-35%. 17. The process of claim 1, wherein the bleached pulp has a consistency of about 12% and a third filtrate. 18. The process of claim 1, further comprising storing the bleached pulp. 19. The process of claim 1, further comprising pressing the bleached pulp to a consistency of about 50%. 20. The process of claim 1, further comprising storing the second filtrate in a second first combined filtrate tank. 21. The process of claim 20, wherein the second combined filtrate tank is in fluid communication with the first recycled filtrate loop. 22. The process of claim 1, further comprising storing the third filtrate in a third combined filtrate tank. 23. The process of claim 22, wherein the third combined filtrate tank is in fluid communication with the first recycled filtrate loop. 24. The process of claim 1, further comprising controlling a fluid level in or diluting a residual bleaching agent concentration in the first recycled filtrate loop with a recycled filtrate obtained from a location (12) of a second recycled filtrate loop. 25. The process of claim 24, wherein a concentration of residual bleaching agent is higher in the first recycled filtrate loop than in the second recycled filtrate loop. 26. The process of claim 24, wherein the second recycled filtrate loop is in fluid communication with an upstream storage tank. 27. The process of claim 24, wherein the second recycled filtrate loop is in fluid communication with an upstream storage tank, and wherein the upstream storage tank is in fluid communication with a discharge line to discharge a recycled filtrate. 28. A process for making a paper product, comprising: the process of claim 1; andproducing a paper product from at least a portion of the bleached pulp. 29. A process for making bleached pulp, comprising: (a) contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location (3) of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency;(b) bleaching the first pulp mixture, to obtain a first bleached pulp mixture;(c) pressing the first bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate;(d) sending at least a portion of the second filtrate to a second location (5) of the first recycled filtrate loop, wherein the second location (5) is downstream of and in fluid communication with the first location (3);(e) contacting the first pressed bleached pulp mixture with a second recycled filtrate obtained from a third location (6) of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location (6) is downstream of and in fluid communication with the second location (5);(f) bleaching the second pulp mixture, to obtain a second bleached pulp mixture;(g) pressing the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate;(h) sending at least a portion of the third filtrate to a fourth location (8) of the first recycled filtrate loop, wherein the fourth location (8) is downstream of and in fluid communication with the third location (6);(i) recycling at least a portion of the third filtrate in the first recycled filtrate loop to the first location (3); andcontacting the second pressed bleached pulp mixture with a third recycled filtrate obtained from a second location (9) of a second recycled filtrate loop, to produce a third pulp mixture;to obtain the bleached pulp. 30. The process of claim 29, wherein the second recycled filtrate loop is not in fluid communication with the first recycled filtrate loop. 31. The process of claim 29, wherein the first recycled filtrate loop comprises a residual bleaching agent. 32. The process of claim 29, wherein the second recycled filtrate loop is free of residual bleaching agent. 33. The process of claim 29, wherein the second recycled filtrate loop is in fluid communication with the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof. 34. The process of claim 29, wherein the first recycled filtrate loop contains a higher concentration of residual bleaching agent than does the second recycled filtrate loop. 35. The process of claim 29, further comprising diluting the third pulp mixture. 36. The process of claim 29, further comprising diluting the third pulp mixture with a recycled filtrate obtained from a location (10) of the second recycled filtrate loop, wherein the location (10) is downstream of the second location (9). 37. A process for making a paper product, comprising: the process of claim 29; andproducing a paper product from at least a portion of the bleached pulp. 38. A process for making bleached pulp, comprising: (a) contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location (3) of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency;(b) bleaching the first pulp mixture, to obtain a first bleached pulp mixture;(c) pressing the first bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate;(d) sending at least a portion of the second filtrate to a second location (5) of the first recycled filtrate loop, wherein the second location (5) is downstream of and in fluid communication with the first location (3);(e) contacting the first pressed bleached pulp mixture with a second recycled filtrate obtained from a third location (6) of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location (6) is downstream of and in fluid communication with the second location (5);(f) bleaching the second pulp mixture, to obtain a second bleached pulp mixture;(g) pressing the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate;(h) sending at least a portion of the third filtrate to a fourth location (8) of the first recycled filtrate loop, wherein the fourth location (8) is downstream of and in fluid communication with the third location (6);(i) recycling at least a portion of the third filtrate in the first recycled filtrate loop to the first location (3);pressing the second pressed bleached pulp mixture to obtain the bleached pulp and a fourth filtrate; andsending at least a portion of the fourth filtrate to a third location (11) of a second recycled filtrate loop;to obtain the bleached pulp. 39. The process of claim 38, wherein the second recycled filtrate loop is not in fluid communication with the first recycled filtrate loop. 40. The process of claim 38, wherein the first recycled filtrate loop comprises a residual bleaching agent. 41. The process of claim 38, wherein the second recycled filtrate loop is free of residual bleaching agent. 42. The process of claim 38, wherein the second recycled filtrate loop is in fluid communication with the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof. 43. The process of claim 38, wherein the first recycled filtrate loop contains a higher concentration of residual bleaching agent than does the second recycled filtrate loop. 44. The process of claim 38, further comprising sending at least a portion of the fourth filtrate in the second recycled filtrate loop to an upstream storage tank. 45. The process of claim 38, further comprising sending at least a portion of the fourth filtrate in the second recycled filtrate loop to the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof. 46. The process of claim 38, further comprising diluting the second pressed bleached pulp mixture prior to pressing the second pressed bleached pulp mixture. 47. The process of claim 38, further comprising storing the bleached pulp. 48. The process of claim 38, further comprising one or more of sending at least a portion of the fourth filtrate in the second recycled filtrate loop to an upstream storage tank; sending at least a portion of the fourth filtrate in the second recycled filtrate loop upstream for contacting with the second pressed bleached pulp mixture; sending at least a portion of the fourth filtrate in the second recycling loop to the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof; or a combination thereof. 49. A process for making a paper product, comprising: the process of claim 38; andproducing a paper product from at least a portion of the bleached pulp. 50. A process for making bleached pulp, comprising: (a) contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location (3) of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency;(b) bleaching the first pulp mixture, to obtain a first bleached pulp mixture;(c) pressing the first bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate;(d) sending at least a portion of the second filtrate to a second location (5) of the first recycled filtrate loop, wherein the second location (5) is downstream of and in fluid communication with the first location (3);(e) contacting the first pressed bleached pulp mixture with a second recycled filtrate obtained from a third location (6) of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location (6) is downstream of and in fluid communication with the second location (5);(f) bleaching the second pulp mixture, to obtain a second bleached pulp mixture;(g) pressing the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate;(h) sending at least a portion of the third filtrate to a fourth location (8) of the first recycled filtrate loop, wherein the fourth location (8) is downstream of and in fluid communication with the third location (6);(i) recycling at least a portion of the third filtrate in the first recycled filtrate loop to the first location (3);contacting the second pressed bleached pulp mixture with a third recycled filtrate obtained from a second location (9) of a second recycled filtrate loop, to produce a third pulp mixture;pressing the third pulp mixture to obtain the bleached pulp and a fourth filtrate; andsending at least a portion of the fourth filtrate to a third location (11) of the second recycled filtrate loop;to obtain the bleached pulp. 51. The process of claim 50, wherein the second recycled filtrate loop is not in fluid communication with the first recycled filtrate loop. 52. The process of claim 50, wherein the first recycled filtrate loop comprises a residual bleaching agent. 53. The process of claim 50, wherein the second recycled filtrate loop is free of residual bleaching agent. 54. The process of claim 50, wherein the second recycled filtrate loop is in fluid communication with the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof. 55. The process of claim 50, wherein the first recycled filtrate loop contains a higher concentration of residual bleaching agent than does the second recycled filtrate loop. 56. The process of claim 50, further comprising sending at least a portion of the fourth filtrate in the second recycled filtrate loop to an upstream storage tank. 57. The process of claim 50, further comprising sending at least a portion of the fourth filtrate in the second recycled filtrate loop to the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof. 58. The process of claim 50, further comprising diluting the second pressed bleached pulp mixture prior to pressing the second pressed bleached pulp mixture. 59. The process of claim 50, further comprising storing the bleached pulp. 60. The process of claim 50, further comprising one or more of sending at least a portion of the fourth filtrate in the second recycled filtrate loop to an upstream storage tank; sending at least a portion of the fourth filtrate in the second recycled filtrate loop upstream to the second location (9) in the second recycled filtrate loop, sending at least a portion of the fourth filtrate in the second recycling loop to the first recycled filtrate loop to either control a fluid level in the first recycled filtrate loop, to dilute a residual bleaching agent level in the first recycled filtrate loop, or a combination thereof; or a combination thereof. 61. A process for making a paper product, comprising: the process of claim 50; andproducing a paper product from at least a portion of the bleached pulp.