Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
  • D21B1/00—Fibrous raw materials or their mechanical treatment
  • D21B1/02—Pretreatment of the raw materials by chemical or physical means
  • D21B1/026—Separating fibrous materials from waste
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
  • D21B1/00—Fibrous raw materials or their mechanical treatment
  • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
  • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
  • D21B1/30—Defibrating by other means
  • D21B1/32—Defibrating by other means of waste paper
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/64—Paper recycling

Definitions

• the present invention relates to the field of treatments to recover raw material and energy from waste materials.
• a treatment of waste material from a pulper of the paper industry which allows recovery, with advantageous energy balance and in an eco-compatible manner, of the paper, plastic and metal fractions constituting said material, increasing the overall energy efficiency of the paper production process.
• the pulper is a pulper of varied capacity, used in the initial step of the paper production cycle; water and fibrous material are fed therein; thanks to an impeller that moves at high speed, the fibers are separated and hydrated to produce a suspension with variable density; the suspension is then transferred to other plants where it is subjected to further treatments such as refining, the addition of charges, glues and any dyes, felting, pressing and drying, to obtain the final sheet.
• the pulper is also used to produce recycled paper: in this case water and pulped paper are mixed in appropriate proportions; the suspension then follows the normal paper production chain according to the steps mentioned above.
• the work of the pulper always generates, as by-product, a certain amount of non- pulpable waste material; when pulped paper is used as raw material, the waste material is constituted by the foreign materials that always come with this product, prevalently plastics, metals, wire, rope, etc., and a noteworthy percentage (approx. 25% of the total waste material) of paper fiber which is retained by said waste. These waste materials can also be present even when starting out from wood fiber.
• This assembly of elements allows separation of the characteristic components of waste from the pulper, such as metal, plastic and paper.
• the overall energy cost of the process lower than the cost of disposing with untreated waste, is further reduced by the possibility of selling/re-utilizing the discrete components recovered, and/or recovering energy through combustion.
• the modular nature of the system also allows the number of steps to be interchanged and/or reduced according to the quali-quantitative composition of the waste, further increasing the overall energy efficiency of the process.
• FIGURES Figure 1 block diagram of the post-pulper modular system forming the object of the invention.
• Figure 2 photograph of industrial prototype: (f): conveyor line for coarse fraction; (g) collection line for paper fraction; (h) collection silo for paper fraction; (i) collection line for plastic fraction; (I) container for plastic fraction.
• FIG. 3 detail of the fine/coarse fraction separator (b). DETAILED DESCRIPTION OF THE INVENTION
• the present process utilizes, as raw material, the waste material from the pulper, already separated from the aqueous suspension intended to produce paper.
• This waste material can be recovered from the pulper, stored separately and later treated according to the present invention, or it can be conveyed from the operating pulper and treated directly without intermediate storage.
• the operating diagram of the modular system of the invention is presented in Figure 1.
• the first element is constituted by the grinder (a).
• the object of this element is to reduce the waste from the pulper, normally tangled in the form of plaits of variable dimensions, into a sufficiently comminuted and flowing product. Any mechanical apparatus capable of performing this grinding operation can be utilized as element (a).
• the grinding action can take place in a single passage or repeated grinding can take place through cyclical movement of the material through the same pair of wheels, or by providing a series of several pairs of said wheels through which the material is fed.
• the grinding action can be facilitated with the aid of water jets, vibrations or other systems, in order to promote movement of the material and/or prevent residues from adhering to the surface of these wheels.
• the material delivered from the grinder is conveyed using suitable means, such as conveyor belts, into the coarse and fine fraction separator (b), also called screen. Any mechanical apparatus capable of performing this function can be used as the element (b).
• the material coming from (a) is conveyed inside the tubular element appropriately made to rotate.
• the fine fraction, full of paper fiber, passes through the holes, is collected and, preferably, recycled in the pulper; alternatively, it can be subjected to separate processes to refine and recover the paper fiber.
• the paper fraction is handled with suitable systems, such as conveyor belts, augers, pneumatic systems, depending on the density and rheological qualities of said fraction.
• the unprocessed coarse fraction, full of metal material, plastic and larger aggregates of paper fiber does not pass through the holes and proceeds inside the tubular element suitably pushed by the pressure of the incoming material and by the rotational movement of the element (b); upon delivery from (b), it is conveyed by means of appropriate conveyor means into the modular element (c), the soft and hard fraction separator.
• Any mechanical apparatus capable of performing this separation can be utilized as the element (c).
• it is constituted by a suitably adapted washing machine.
• the material to be separated is treated with a high pressure water recirculation system that carries the soft material in suspension; the hard material is instead retained by suitable filters through which the suspension is fed.
• the suspension of soft material, full of paper fibers is preferably recycled in the pulper; alternatively, it can be subjected to separate processes to refine and recover the paper fiber.
• the hard fraction is recovered from the filters and subjected to drying.
• At least one collection point for the metal fraction through suitable metal fraction separators (d). Collection preferably takes place by placing the material on a conveyor belt moving in the range of action of an electromagnet, which attracts and separates the magnetic metals, and of an appropriate electromagnetic field, which repels and separates the non-magnetic metals (obtainable for example by means of the product Eddy Current, Art 901 , soc. Calamit, Cologno Mz.se).
• the preferred points for this collection are located along the path between the elements (b) and (c), and/or after the element (c).
• the use of two metal collection points is particularly preferred as it allows more complete separation of this element.
• the remaining fraction delivered from the cycle a-b-c-d is prevalently constituted by plastic. This fraction can be stored and used as plastic to be recycled, or can be burnt with the aim of recovering energy.
• the combustion reactor (e) is chosen from conventional burners suitable for the purpose or, advantageously from the energy and environmental viewpoint, it is constituted by a pyrolyzer, associated with a catalytic oxidation chamber; inside the pyrolyzer, the plastic fraction is heated in an inert gas atmosphere, to a temperature of around 500 0 C; the material vaporizes and is then conveyed by the flow of nitro ⁇ en into the oxidation chamber, fed by a flow of air or pure oxygen; vapor combustion takes place through suitable oxidation catalysts, therefore not in the flame phase.
• Suitable heat exchangers are associated with the combustion reactor, so as to store the heat generated with the aim of recovering energy.
• a dust is produced, prevalently constituted by fine plastic material that adheres to the walls of the various collection elements.
• This material can be recovered, manually or automatically, and then recycled or subjected to combustion as described above for the plastic fraction.
• the process described here therefore allows complete separation and/or recycling or eco-compatible combustion of the elements constituting the waste from the pulper.
• the modular nature of the system allows the composition and sequence of the various elements described above to be varied, depending on the quali- quantitative composition of the initial waste product, thereby optimizing the energy balance of the process.
• the modular system described above can be produced as a separate plant, or be integrated in the production cycle of a paper mill; in the first case it is fed with the waste from the pulper, previously recovered separately; in the second case feed takes place through suitable ducts that convey the waste material coming from the pulper directly towards the modular system.
• the present invention therefore covers the modular system on its own, or integrated within a paper production plant, in particular, but not exclusively, for the production of recycled paper.
• An example of embodiment has been produced on an industrial scale.
• Figure 2 shows the modular system as a whole
• Figure 3 shows the element (b) in detail.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Paper (AREA)
• Processing Of Solid Wastes (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38616378

Family Applications (1)

Country Status (3)

Families Citing this family (4)

Family Cites Families (3)

• 2006
  • 2006-07-11 IT ITMI20061338 patent/ITMI20061338A1/it unknown
• 2007
  • 2007-07-10 WO PCT/IB2007/001923 patent/WO2008007204A1/en active Application Filing
  • 2007-07-10 EP EP20070766618 patent/EP2054547A1/de not_active Withdrawn

Non-Patent Citations (1)

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