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EP-3429767-B1 - DOOR FOR SOLID WASTE PRESS

EP3429767B1EP 3429767 B1EP3429767 B1EP 3429767B1EP-3429767-B1

Inventors

  • OUDE GROTEBEVELSBORG, WILLEM JAN
  • GONELLA, CARLO

Dates

Publication Date
20260506
Application Date
20170316

Claims (13)

  1. A press (10) comprising, a chamber (12), the chamber having an opening; a ram (14) arranged in the chamber (12) and, a sliding door (20) fitted to the opening, the door having an extrusion section (22) and an expulsion section (24) alternately covering the opening of the chamber (12), wherein when the extrusion section (22) is over the opening, the opening is generally closed and waste (18) can be compressed in the chamber (12), wherein holes are provided in the door (20) or in walls of the chamber (12) for removing wet fraction of the waste, and wherein the expulsion section comprises an opening for removing a dry fraction of the waste, wherein when the expulsion section (24) is over the opening of the chamber (12), the ram (14) can extend from the chamber (12) at least partially through the opening of the expulsion section (24).
  2. The press (10) of claim 1 wherein the expulsion section (24) defines a passage that is generally the same size and shape as the opening of the chamber (12).
  3. The press (10) of claim 1 or 2 wherein the expulsion section (24) is above the extrusion section (22).
  4. The press (10) of any preceding claim wherein the extrusion section (22) comprises openings for a wet fraction (32) of waste (18) to pass through the door (20).
  5. The press (10) of any preceding claim wherein the door (20) is slidable within a frame (26) and at least part of the door frame (26) is movable relative to the chamber (12).
  6. The press (10) of any preceding claim wherein the door (20) is slidable within a frame (26) and the side of the frame (26) has a pressure release channel (48).
  7. A method of pressing waste (18) comprising, moving a ram (14) in a chamber (12) while an opening in the chamber (12) is covered by an extrusion section (22) of a sliding door (20) for compressing waste (18) in the chamber (12), wherein a wet fraction leaves the chamber through holes in the in the door (20) or in walls of the chamber (12); lowering the door (20) to bring an opening of the expulsion section (24) over the opening of the chamber (12); and, expelling a dry fraction of the waste from the chamber (12) through the opening of the expulsion section (24) of the door (20) by moving the ram (14) at least partially through the opening of the expulsion section (24).
  8. The method of claim 7 wherein the door (20) slides in a frame (26) forming a vertical passage.
  9. The method of claim 7 or 8 wherein waste is expelled through an opening in the expulsion section (24), wherein the expulsion section (24) is an upper section of the door (20).
  10. The method of claim 9 comprising scraping the upper section of the door (20) with the ram (14).
  11. The method of any of claims 7 to 10 comprising pressing a liquid fraction of waste through the extrusion section (22), wherein the extrusion section (22) is a lower section of the door (20).
  12. The method of any of claims 7 to 11 further comprising a step of moving at least part of the door frame (26) towards the chamber (12) from time to time.
  13. The method of any of claims 7 to 12 further comprising scraping a channel in a side of the frame (26) with a scraper (52) attached to an upper section of the door.

Description

FIELD This specification relates to presses for treating solid waste and methods of operating them. BACKGROUND Solid waste includes, for example, municipal solid waste (MSW), source separated organics (SSO) and waste from industrial, commercial and institutional (ICI) sources. The waste can de divided into various fractions. For example, the organic fraction is the part of the waste that is most easily biodegraded and may also be referred to as organic waste. The organic fraction is primarily made up of food waste, but may also include leaf and yard waste or other materials. The organic fraction is approximately 40% of ordinary MSW after recyclables are removed. SSO may have an organic fraction of 80% or more and ICI wastes can have varying amounts of organic material. Historically, organic waste was landfilled with other solid waste. However, the organic fraction of solid waste is the major cause of greenhouse gas emissions, leachate and odors in landfills. There is a general trend to divert organic waste for biological treatment, for example by anaerobic digestion (AD) or composting. Most biological treatment steps require some preprocessing of the waste such as debagging and sorting to remove large items such as bottles and cans. Certain biological treatments, such as some composting methods and high-solids slurry and wet (low solids) anaerobic digestion, also require that the waste be reduced in size and homogenized. The size reduction is typically done in a device that comminutes the waste, such as a hammer mill, shredder or pulper. In some cases, the comminuting device also provides a coarse separation of contaminants (i.e. material that is not readily biodegraded, such as plastic). Alternatively, a separate separation device may be added. With adequate processing, at least some of the non-organic waste may be used, for example as refuse derived fuel (RDF), rather than landfilled. Recently, there have been various attempts to use presses to separate solid waste into organic and non-organic fractions. The organic fraction may also be called a wet fraction and the non-organic fraction may also be called a dry fraction. In general, the solid waste is loaded into a chamber having a porous wall. A hydraulic ram compresses the waste, which causes liquids and soft materials (i.e. food waste) to be squeezed through the porous wall. Large pieces of primarily non-organic waste are retained in the chamber. The non-organic fraction can also include materials, such as wood, that are organic but would be difficult to digest. The non-organic waste is rejected through a door of the chamber. In some (but not all) cases the pressure of the ram is enough to break open cell walls in the organic waste that is squeezed through the porous wall. US Publication 2013/0316428 describes one process in which an organic fraction is separated from solid waste in a press. The organic fraction is extruded through a grid having small-bore holes, under a pressure higher than the burst pressure of the cell membranes. The cells are disrupted and a gel or paste of a doughy consistency is produced. The gel can be digested in an anaerobic digester. Some examples of presses are described in European Publication Nos. 1207040 and 1568478, International Publication WO 2010/097177, Italian patent application ITTO20111068, EP 0 468 853 A1, EP 2 292 419 A2 and DE 31 13 515 A1. Commercially available presses include, for example, the Biosqueeze press sold by Finsterwalder and the VM 2000, Orex and Biorex presses sold by DB Technologies or Anaergia. EP 0468 853 A1 discloses a press for treating heterogeneous waste products comprising a solid phase and a liquid phase, said press comprising (a) a frame; (b) means defining a feed zone of receiving said waste products, said feed zone having a feed axis and being open adjacent to an upper end thereof and defining two opposed lateral openings, a compression piston movable between one of said openings of said feed zone and a position located beyond the other of said openings, said lateral openings having a section adapted to a corresponding section of said piston; (c) a press chamber having a pressing axis and comprising an inlet opening and an outlet opening which are in opposed relation to each other and disposed coaxially relative to said feed axis of said feed zone, said chamber having a section equal to a section of said compression piston, means for recovering said liquid phase, said press chamber comprising calibrated passages connecting said press chamber with said liquid phase recovering means; (d) a chamber for discharging said solid phase located downstream of said press chamber relative to a direction of flow of said waste products through said press chamber; (e) an element having a shape complementary to a shape of said discharging chamber and movable transversely relative to said pressing axis of said press chamber between a first position for closing said outlet opening of said press chamber