Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D99/00—Subject matter not provided for in other groups of this subclass
  • F27D99/0001—Heating elements or systems
  • F27D99/0006—Electric heating elements or system
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B13/00—Conditioning or physical treatment of the material to be shaped
  • B29B13/02—Conditioning or physical treatment of the material to be shaped by heating
  • B29B13/022—Melting the material to be shaped
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B14/00—Crucible or pot furnaces
  • F27B14/06—Crucible or pot furnaces heated electrically, e.g. induction crucible furnaces with or without any other source of heat
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B14/00—Crucible or pot furnaces
  • F27B14/08—Details specially adapted for crucible or pot furnaces
  • F27B14/0806—Charging or discharging devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B14/00—Crucible or pot furnaces
  • F27B14/08—Details specially adapted for crucible or pot furnaces
  • F27B2014/0887—Movement of the melt
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D99/00—Subject matter not provided for in other groups of this subclass
  • F27D99/0001—Heating elements or systems
  • F27D99/0006—Electric heating elements or system
  • F27D2099/0008—Resistor heating

Definitions

• This invention relates to apparatus for the melting and dispensing of thermoplastic material, and more particularly to a heater module structure for such apparatus.
• each first fin of the second module spans the corresponding space between each adjacent pair of second fins of the first module to close all vertical spaces between the adjacent first and second fins and to provide longitudinally staggered vertical holes for the fluid passage of the melted thermplastic material.
• an entire grid surface may be built up to form a complete heating stage for rapidly melting the thermoplastic material.
• an assembly of the above heater modules may be utilized in each stage of the melting apparatus by mounting each, assembled stage within a hopper-type housing having a cross-section of the same shape as, but siightly larger than, the cross-section of the assembled stages.
• Conventional thermoplastic dispensing elements such as a dispensing head and hose, may be incorporated below the various stages assembled fuom the heater modules, for dispensing the melted thermoplastic material.
• various sizes of heating or grid stages may be constructed, with one or more vertically arranged stages, with a minimum of assembly time and materials.
• FIG. 2 is a section taken along the line 2-2 of FIG. 1;
• FIG. 3 is a section taken along the line 3-3 of FIG. 1;
• FIG. 4 is an enlarged fragmentary section taken along the line 4-4 of FIG. 3;
• FIG. 5 is a fragmentary section taken along the line 5-5 of FIG. 4;
• FIG. 6 is a fragmentary top perspective view of a plurality of heater modules assembled in a pre-melting stage. Best Mode For Carrying Out The Invention
• a hopper 15 for receiving the thermoplastic material 16 in its solid form.
• a protective casing or jacket 18 may enclose, and be spaced from, the outer surface of the heating receptacle. As shown, the hopper 15 is integral with the jacket 18.
• a gear pump 20 is driven by motor 21 through sprocket-chain transmission 22 and the driven shaft 23 to move the molten thermoplastic material 24 through the conduit block 12 into the heated dispensing head 25.
• Hose 26 conveys the hot thermoplastic material 24 from the dispensing head 25, preferably through a nozzle 27, to a point of discharge.
• the controls for the apparatus 10 are mounted in the control housing 29 on the outside of the jacket 18.
• a plurality of heater modules 30, made in accordance with this invention, are assembled within the heating receptacle 14 to provide an upper, or pre-melt, stage 31 and a lower, melting, or progressive melting stage 32.
• Each module 30 includes an elongated body 34 of thermally conductive material.
• Each elongated body 34 includes an elongated substantially rectangular core 35 of substantial height or depth having a plurality of first and second fins 36 and 37 projecting from opposite sides of the core 35.
• Each of the first and second fins 36 and 37 is a substantially uniform, rectangular cross-section.
• the first fins 36 and the second fins 37 are uniformly longitudinally spaced apart to form recesses 38 and 39, respectively, of uniform longitudinal dimensions equal to the longitudinal dimension of each of the fins 36 and 37.
• the second fins 37 are longitudinally staggered relative to the first fins 36 so that a fin 37 is in lateral alignment with a first recess 38, while each first fin 36 is in lateral alignment with a corresponding second recess
• a heating stage is built up by assembly of a plurality of modules 30 longitudinally parallel and adjacent to each other, with the first fins 36 of the second module 30' (FIG. 6) opposite and aligned with a second recess 39 in the first module 30, such that the lateral outer vertical face of the fin 36 closes the recess 39.
• the outer vertical face of each fin 37 closes an opposing recess 38.
• the closed recesses 38 and 39 form longitudinally staggered vertical holes, each hole having a rectangular cross-section, completely enclosed laterally and longitudinally, but vertically open to pro vide a fluid passage for the molten thermoplastic material 24.
• Each group of parallel modules 30. in each stage 31 and 32 may be held in assembled position by the ganging bars 50 at each end of the module 30.
• the ganging bars 50 may be connected together by the vertical connecting bars 41 and suspended from the upper edge of the hopper 15 by the hanger bars 52.
• the method of supporting the assembled modules 30 by the hanger bars 52 prevents any fastener members from penetrating the walls of the heater receptacle 14, to eliminate leakage of the very hot molten thermoplastic material 24.
• the thermal sensing elements 43 for each heating stage 31 and 32 are connected to separate and independent the ⁇ nostatic controls, so that the pre-melt stage 31 may be heated to and maintained at a lower temperature than the progressive melt or melting stage 32, as described in the prior U.S. Mercer patent 3,531,023.
• thermoplastic melting devices and apparatus may be easily and very quickly and economically assembled, regardless of the number of vertical stages required, and regardless of the transverse size and capacity of the apparatus desired.
• top walls 56 and 57 of the respective fins 36 and 37 are sloped, so that they decline laterally from the core 34 to facilitate drainage of the molten thermoplastic material 24 downward into, the corresponding vertical holes 38 and 39, to prevent unwanted accumulation of the thermoplastic material on top of the modules 30 and 30'. It is also within the scope of this invention to provide horizontal holes in the core 34 to receive heating elements, such as heating elements 40, longitudinally horizontally within the core 34.
• the monolithic thermally conductive material incorporated in each of the modules may be of an aluminum alloy, such as aluminum alloy No. 202413 or aluminum alloy 6061T6.
• a pre-melt stage 31 or progressive melting stage 32 has been designed which affords a greater ratio of heating surface to the opening areas for the thermoplastic material, thereby reducing the melting time and increasing the flew velocity of the thermoplastic material 24 through the respective melting stages 31 and 32, respectively.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Coating Apparatus (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22154417

Family Applications (1)

Country Status (4)

Cited By (3)

Citations (10)

Family Cites Families (2)

• 1980
  • 1980-06-30 WO PCT/US1980/000825 patent/WO1982000193A1/en not_active Ceased
  • 1980-06-30 AU AU69275/81A patent/AU6927581A/en not_active Abandoned
  • 1980-06-30 JP JP50096580A patent/JPS57500914A/ja active Pending
  • 1980-06-30 EP EP19810900697 patent/EP0054548A4/en not_active Withdrawn

Patent Citations (10)

Non-Patent Citations (1)

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