Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
  • F26B21/02—Circulating air or gases in closed cycles, e.g. wholly within the drying enclosure
  • F26B21/022—Circulating air or gases in closed cycles, e.g. wholly within the drying enclosure with provisions for changing the drying gas flow pattern, e.g. by reversing gas flow, by moving the materials or objects through subsequent compartments, at least two of which have a different direction of gas flow
  • F26B21/028—Circulating air or gases in closed cycles, e.g. wholly within the drying enclosure with provisions for changing the drying gas flow pattern, e.g. by reversing gas flow, by moving the materials or objects through subsequent compartments, at least two of which have a different direction of gas flow by air valves, movable baffles or nozzle arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
  • F26B13/10—Arrangements for feeding, heating or supporting materials; Controlling movement, tension or position of materials

Definitions

• the invention relates to a convection oven according to the preamble of patent claim 1.
• Convection ovens for drying and / or melting, briefly for treating material webs passed through the furnace, in particular textile material webs comprise a housing in which a means of transport for passing a material web are arranged. Above and below the means of transport, nozzle boxes are arranged parallel to one another and parallel to the direction of transport, and nozzles are formed on their opposite side faces facing the means of transport. Air is blown onto the material web with the nozzles.
• the nozzle boxes are arranged in a closed outflow chamber, from which the air emerging from the nozzles is sucked off and - heated and compressed - is fed back to a pressure chamber in order to be blown through the nozzles onto the material web again.
• the circulating air dryer known from EP-AI 148 113 which is constructed in the manner described above, has the disadvantage that the air blown onto the material web is supplied to the material web in a well-controlled manner, but does not flow out of there in a controllable manner, because, depending on the surface quality, density and the thickness of the material web and the distance between the printing boxes there are no constant conditions.
• a device for heat treatment of a web is also known, in which each nozzle box is assigned a channel with positive pressure and a channel with negative pressure. Flaps on the ducts allow the nozzles to either blow air onto the web of material on both sides, or to extract air from there, or to suck on one side and blow on the other side. Furthermore, the nozzle boxes lie side by side, so that the blown-in air is sucked out again by an adjacent one or the opposite one.
• a disadvantage of this device is that it is not possible to flow through the web alternately from bottom to top and from top to bottom.
• the invention seeks to remedy this.
• the object of the present invention is therefore to create a circulating air oven which enables a controlled inflow and outflow of process air to and away from the material web according to essentially freely selectable criteria. This object is achieved by a convection oven according to the features of patent claim 1.
• a connection between the nozzle spaces and the nozzle boxes can be created either with a suction space or a pressure space in order to direct air flowing out of the one nozzle through the material web and to suck it off through the suction nozzles.
• This enables optimal flow of process air through the material web. This leads to a uniform treatment of the material web over its entire material cross section.
• the air can be distributed particularly advantageously transversely to the material web if the nozzle boxes are alternately arranged in mirror image.
• the circulating air oven according to the invention also allows the amount of air supplied to each nozzle box to be narrowly adjusted and changed along the passage of the material through the circulating air oven.
• the air guidance can be very simplified and, for example, in the direction of transport of the material web, air can be guided in overpressure on one side and air in vacuum on the other side.
• the convection oven can be constructed in a modular manner, namely in that the air-guiding, laterally arranged boxes are set up independently of the length of the nozzle boxes arranged between them.
• FIG. 1 shows a schematic illustration of a conventional type convection oven
• FIG. 2 shows a cross section through a conventional nozzle box along line II-II in FIG. 1
• 3 shows a cross section through the convection oven according to the invention
• FIG. 4 shows a vertical section through the two nozzle boxes according to FIG. 3
• FIG. 5 shows a top view of the upper nozzle box in FIG. 3
• FIG. 6 shows a schematic representation of a further advantageous embodiment
• FIG. 7 shows a vertical section through a nozzle box with an elastic band as a flap
• FIG. 8 shows an oblique view of a group of nozzle boxes on the flap side
• FIG. 9 shows a vertical section through a convection oven with a rectangular cross section (nozzles set to "blow” above and below)
• FIG. 10 shows a vertical section through a convection oven with a rectangular cross section (Nozzles have “blow” above, “suck” below).
• FIG. 11 shows a top view of a convection oven with nozzle boxes according to FIGS. 9 and 10.
• FIG. 1 The structure of a convection oven 1 known from EP-AI 148 113 shown in FIG. 1 comprises an insulated housing 3, the interior of which is subdivided into a pressure chamber 5, a return flow chamber 7 and a heating chamber 8.
• the heating chamber 8 is connected to the backflow chamber 7 via a filter element 11.
• a blower 15 for example an axial blower, is installed in the wall 13 between the pressure chamber 5 and the heating chamber 8.
• the return flow space 7 comprises at least one means of transport 17, preferably a circumferential conveyor belt 21 guided around a plurality of deflection rollers 19.
• the conveyor belt 21 is made of an air-permeable material such as a gauze, a net or a grid made of metal or plastic and is driven by a motor M.
• a second transport means 17 ' can also be arranged above the first, such that two strands 23 and 23' run parallel to one another and a material web 27 is guided between them.
• the distance between these two runs 23, 23 ' is preferably adjustable to the thickness of the material web 25 guided between them.
• the material web 25 is guided by the two transport means 17 in the direction of arrow T through the forced air oven 1.
• a plurality of nozzle boxes 27 arranged in series next to one another are arranged below and above the transport means 17.
• the nozzle boxes 27 extend at right angles to the transport direction T of the material web 27 over its entire width, ie they extend over the width of the conveyor belt 21.
• the nozzle boxes 27 have a cross section narrowing from the air inlet side 31.
• a pressure flap 35 is articulated, with which the
• Opening cross section 37 to the pressure chamber 5 can be completely or partially closed (see also FIG. 2). This known arrangement enables the
• the air impinging on the material web 25 escapes uncontrollably to the side of the nozzle boxes 27 and can reach the backflow chamber 7 through the spaces between the adjacent nozzle boxes 27.
• the convection oven 1 comprises, in addition to the pressure chamber 5 and the return flow chamber 7, a suction chamber 39. This can extend next to the pressure chamber 5 and / or be penetrated by the nozzle boxes 27.
• the suction chamber 39 is in direct connection with the heating chamber 8.
• a through opening 41 between the suction chamber 39 and the heating chamber 8 is spanned by a filter element.
• a second passage 43 between the suction chamber 39 and the backflow chamber 7 is preferably adjacent to the passage opening 41 from the suction chamber 39 into the heating chamber 8 educated.
• the passage 43 can be completely or partially closed by a slide 45.
• suction flaps 49 are arranged, which allow the suction of air with the nozzles 29.
• the air flow in the inventive convection oven according to FIG. 3 does not differ from that in the known convection oven when the suction-side closure means, such as suction flaps 49, are closed and the slide 45 to the suction side of the fan 15 is open. Then the air then flows out of the nozzles 29 of the nozzle boxes 27 onto the material web 25 and from there uncontrollably between the adjacent nozzle boxes 27 into the return flow chamber 7 and further through the filter 11 into the heating chamber 8.
• the warm air now flows from the upper nozzle boxes 27 from the nozzles 29 through the material web 25 and is sucked in by the nozzles 29 due to the negative pressure present in the lower nozzle boxes 27 or vice versa.
• the warm air consequently not only contacts the upper side of the material web 25, but it is sucked through the material web 25 and comes into contact with all parts of the material web 25 and, as a side effect, the air is filtered, ie fibers and lint detached from the surface remain in the material web 25, so that only a small number of fibers or lint can reach the filter 11 through the suction space 39. So that no air can flow out laterally and leave the flow direction perpendicular to the material web 25, 29 nozzle beds 30 are formed between the nozzles. These form surfaces lying parallel to the material web 25 between the nozzles 29.
• the suction flaps 49 can be opened and the pressure flaps 35 closed or vice versa on the nozzle boxes 27 which form a heating nozzle column and are connected in parallel, or vice versa that the flow takes place alternately or in sections from bottom to top or from top to bottom.
• the advance of the material web 25 through the transport means 17 causes a continuous change in the air flow direction in the material web 25.
• An extremely uniform flooding of the material web 25 with warm air can thus be achieved over the entire thickness of the material web 25.
• FIG. 6 shows schematically a further advantageous embodiment of the invention.
• the nozzle boxes 27 are connected by a line 51 to a reusable valve 53 or a reusable cap, with which a connection to a pressure line P or a suction line S can optionally be established.
• the pressure line P is connected to a blower V, which is connected on the suction side to the suction line S.
• a filter F, a suction fan S and / or a heater H or a refrigerator C can be used.
• FIG. 6 only two nozzle boxes 27, which lie opposite one another, are represented as representative of a plurality of nozzle boxes 27.
• the nozzle boxes 27 are covered by formwork 59 mounted on the end face, so that the processing space 61 between the Nozzle boxes 27, through which the material web 25 is passed, are closed.
• the intermediate space between the individual nozzle boxes 27 lying opposite one another in pairs can also be closed by appropriate cladding, or the nozzle boxes 27 can be lined up without a mutual spacing.
• An insulation layer 63 prevents heat exchange with the surroundings.
• the air flow over or through the material web from pressure box to pressure box 27 can be adjusted.
• the air emerging from the pressure boxes 27 with overpressure is sucked out through the slots on pressure boxes 27 connected to the suction side. This eliminates an uncontrolled flow of air between the pressure boxes. In contrast to that described at the outset, this arrangement enables optimal access to the material web 25.
• this arrangement enables the supply of warm air as well as cold or possibly humidified air.
• the sucked back air can also be cleaned in a filter F.
• the pressure blower V can be supported by a suction blower S.
• Switching the multi-way valves 53 can be done manually or when using Electromagnetically controllable valves are made by the machine control. Depending on the design of the valves 53, the amount of air that has flowed in / extracted can also be controlled in each individual pressure box 27.
• the air outlet cross sections of the nozzles 29 can be adjusted. This makes it possible, for example, to supply a small amount of warm air to the material web 25 at the start of the heat treatment and to increase this amount successively, be it until the end of the throughput section or only over a certain area and then by reducing the cross sections by reducing the amount again.
• a suitable air quantity control can also be achieved by an arrangement according to FIGS. 6 and 7.
• FIGS. 7 and 8 A particularly advantageous embodiment of a closure means cap is shown in the embodiment of the invention according to FIGS. 7 and 8.
• This comprises a flexible sheet or plastic and, in short, band 71, which is guided in guides 73 arranged laterally on the nozzle boxes 27.
• the band 71 can be moved from a closed position, in which the passage for air between the nozzle box 27 and the pressure chamber (5) and the suction chamber (7) is closed, into an open position or intermediate position, which defines the passage releases completely or to the desired extent.
• the belt 71 is preferably moved by hand.
• a tab 75 is formed on a band end.
• the band 71 is held self-locking in the guides 73 and can therefore be brought into any desired position and held there without any further technical measures. An electro-mechanical shift is also possible.
• the nozzle boxes 27 are cubic, i.e. also rectangular in vertical section.
• the supply of air (pressure-side opening 85) takes place from the left-hand side from a pressure space 5 arranged along the circulating-air oven 1.
• the suction of air takes place on the right-hand side through an opening 87 into a suction space 39, which also extends over the length of the circulating-air oven 1 extends.
• the suction chamber 39 and the pressure chamber 5 are connected to one another by fans, as in the previous examples.
• This design of the nozzle boxes 27 results in a very balanced air distribution transverse to the material web and regardless of the flow direction of the air prevailing in the nozzle boxes 27.
• FIGS. 9 to 11 show, in addition to the nozzle boxes 27 arranged one above the other, the passage space 77 for the material web 25.
• Inside the nozzle boxes 27 are horizontal pivot axes A, which are preferably mounted in at least one of the side walls 27 'and 27 ", can be seen on each pivot axis A, which divides the interior of the nozzle box 27 essentially diagonally into two wedge-shaped halves.
• the two parallel to the axis A running edges 81 of the switching flap 79 are preferably at a distance from the end walls of the nozzle boxes on the lower and upper side walls 27 ', 27 ".
• the switching flap 79 does not run exactly diagonally through the nozzle box 27 in order to allow the flap 79 to be pivoted from one diagonal (FIG. 9 below) to the other diagonal (FIG. 10 below) without touching the end walls .
• the pivoting can be done with a handle 83 attached to the suction or pressure side end of the switching flap 79.
• a closing flap 89 which is guided by a guide element 91, is preferably articulated on the pressure-side end of the switching flap 79.
• the closing flap 89 is guided in front of the opening 85 in the nozzle box 27 and closes the latter in the “suction position”.
• the upper nozzle box 17 is connected to the pressure chamber 5.
• the changeover flap 79 rests with its one edge 81 at the top left and with the other edge at the bottom right of the nozzle box 17.
• the switching flap 79 allows air to enter from the pressure chamber 5 through the opening 85 adjoining the pressure chamber 5 in the nozzle box 27 and from there through the nozzles 29 to the material web 25.
• the suction chamber 39 is probably connected to the upper half of the nozzle box 27, however, because of the switching flap 79 there is no connection to the nozzles 29.
• Each of the nozzle boxes 27 can be individually connected to either the suction chamber 39 or the pressure chamber 5.
• Both the pressure chamber 5 and the suction chamber 39 are connected to a plurality of nozzle boxes 27.
• nozzle boxes 27 Depending on the material web width that is to be processed, nozzle boxes 27 with a corresponding length L are used. Consequently, nozzle boxes 27 of different lengths can be used Always identical pressure chambers 5 or suction chambers 39 are used, which consequently enable modular production of the convection ovens 1.
• the circulating air oven 1 or the various freely selectable options for supplying or removing air gives the user a means of adapting the course of the heat treatment exactly to the material to be dried or treated.
• the circulating air oven 1 according to the invention proves to be particularly advantageous if the material web 25 is pressed within the housing 3 during the heat treatment by the nozzle boxes 27 or pressure plates arranged thereon (not shown).
• suitable nozzles 29 can be provided that the material web 25 transported in the transport direction T is set in vibration. An additional vibration or oscillation device for loosening the material web 25 can thus be omitted.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatment Of Fiber Materials (AREA)
• Drying Of Solid Materials (AREA)
• Glass Compositions (AREA)
• Electric Stoves And Ranges (AREA)
• Cookers (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=33557704

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Family Cites Families (18)

• 2004
  • 2004-06-28 EP EP04738043A patent/EP1642073B1/fr not_active Not-in-force
  • 2004-06-28 WO PCT/CH2004/000402 patent/WO2005003661A1/fr active IP Right Grant
  • 2004-06-28 US US10/562,657 patent/US7296995B2/en active Active
  • 2004-06-28 AT AT04738043T patent/ATE386913T1/de not_active IP Right Cessation
  • 2004-06-28 DE DE502004006262T patent/DE502004006262D1/de active Active

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events