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EP-4302032-B1 - DRYER AND DRYING UNIT FOR DRYING PAPER TUBES

EP4302032B1EP 4302032 B1EP4302032 B1EP 4302032B1EP-4302032-B1

Inventors

  • OWCZAREK, RADOSLAW
  • KOWALCZYK, Tadeusz

Dates

Publication Date
20260506
Application Date
20220302

Claims (10)

  1. A drying unit (1) for drying paper tubes (4) conveyed in a multilayer stream (W), comprising a dryer (2) and a conveyor (3) of the multilayer stream (W), wherein the dryer (2) for drying paper tubes (4) conveyed in the multilayer stream (W) transversely to the axis of the paper tubes (4) comprising an inlet (6) adapted to receiving a conveyor (3) of the multilayer stream (W) so that the conveyor passes through the inlet (6), an outlet (7) adapted to receiving the conveyor (3) of the multilayer stream (W) so that the conveyor passes through the outlet (7), at least one drying chamber (5) situated between the inlet (6) and the outlet (7), adapted to receive the conveyor (3) of the multilayer stream (W), at least one heater (8) to heat the air, at least one fan (9) to blow the heated air into the drying chamber (5), wherein at least one wall (13, 14) of the dryer (2) is provided with at least one blowing element (15) for the heated air, wherein the conveyor (3) of the multilayer stream (W) is provided with two supporting surfaces (33, 34) adapted to hold the multilayer stream (W) at two sides, wherein the blowing element for the heated air is adapted to blow the heated air in the blowing direction (R) substantially parallel to the supporting surfaces of the conveyor of the multilayer stream (W) characterized in that the blowing direction (R) of the heated air through the blowing element is situated substantially transversely to the longitudinal axis (k) of the drying chamber of the dryer, and in that the blowing direction (R) of the heated air through the blowing element is transverse to the conveying direction (V) of the multilayer stream (W) of the paper tube, and in that the blowing direction (R) of the heated air is in line with the axes (t) of the paper tubes (4) conveyed in the multilayer stream (W).
  2. The drying unit (1) as in claim 1 wherein at least one of the two opposite walls (13, 14) of the drying chamber (5) is provided with the blowing elements (15) for blowing the heated air.
  3. The drying unit (1) as in claims 1 or 2, wherein the dryer is provided with at least two drying zones (H1, H2) at least partially separated from each other, the drying zone (H1, H2) being provided with a fan (9).
  4. The drying unit (1) as in claim 3, wherein successive drying zones (H1, H2) the blowing elements (15) are arranged respectively on different sides of the drying chamber (5).
  5. The drying unit (1) as in claim 3 or 4, wherein the heating chambers (16) of the drying zones (H1, H2, H3) are separated from each other by walls (23).
  6. The drying unit (1) as in any of claims 3 to 5, wherein in the drying zone (H1, H2, H3) the air circulation (C1, C2, C3) passes through the drying chamber (5), the openings (12) in the front wall (10), the channel (22), the fan (9), the heating chamber (16) and the blowing elements (15) in the side wall (13, 14).
  7. The drying unit (1) as in any of the preceding claims 1 to 6, wherein the drying chamber (5) is positioned vertically.
  8. The drying unit (1) as in any of the preceding claims 1 to 7, wherein the inlet (6) and the outlet (7) are adapted to a conveyor (3) provided with two supporting elements (31, 32).
  9. The drying unit (1) as in any of claims 1 tc 8, characterised in that the supporting surfaces (33, 34) are formed on a chain conveyor.
  10. The drying unit (1) as in any of claims 1 to 9, characterised in that the supporting surfaces (33, 34) are provided with projections (41, 42) situated transversely to the conveying direction (V) of the conveyor (3).

Description

The object of the invention is a drying unit for drying paper tubes. The invention relates to the manufacture of paper products for the food industry, in particular in the manufacture of drinking accessories such as paper drinking straws. The publication GB 1088 745 discloses a rotary tube dryer wherein the tubes circulate around the circumference of the wheels and are individually fed into and carried away from the dryer. The publication GB 291 102 discloses a dryer wherein the cardboard tubes are dried individually and each tube is rotated individually during the drying process. The publication WO 2017/080067A1 discloses a dryer having three drying sections wherein in the first section the drying is performed using hot air, in the second section the drying is performed using microwave radiation, and in the third section the drying is performed using cool air. Also the publications DE 839 444 C and CN 2 518 672 Y disclose drying units according to the prior art. There are known drying units in which heating elements such as an irradiator are used, whereas in these solutions there is one-sided heating of the dried products, which leads to their deformation. Drying units of such type require the use of a single layer arrangement of dried products situated on a horizontal supporting surface. There are known drying units in which the heated air stream is directed from above onto the articles moving horizontally along the conveyor. The invention is defined in the claim 1. The drying unit according to the invention is characterised in that the blowing element for the heated air is adapted to blow the heated air in a blowing direction substantially parallel to the supporting surfaces of the conveyor of the multilayer stream. The drying unit according to the one of its aspects is characterised in that at least one of the two opposite walls of the drying chamber is provided with the blowing elements for blowing the heated air. The drying unit according to the one of its aspects is characterised by being provided with at least two drying zones at least partially separated from each other, the drying zone being provided with a fan. The drying unit according to the one of its aspects is characterised in that in successive drying zones the blowing elements are arranged respectively on different sides of the drying chamber. The drying unit according to the one of its aspects is characterised in that the heating chambers of the drying zones are separated from each other by walls. The drying unit according to the one of its aspects is characterised in that in the drying zone the air circulation passes through the drying chamber, the openings in the front wall, the channel, the fan, the heating chamber and the blowing elements in the side wall. The drying unit according to the one of its aspects is characterised in that the drying chamber is vertically positioned. The drying unit according to the one of its aspects is characterised in that the inlet and the outlet are adapted to a conveyor provided with two supporting elements. The drying unit according to the one of its aspects is characterised in that the blowing element for the heated air is adapted to blow the heated air in the blowing direction substantially parallel to the supporting surfaces of the conveyor of the multilayer stream. The drying unit according to the one of its aspects is characterised in that the supporting surfaces are formed on a chain conveyor. The drying unit according to the one of its aspects is characterised in that the supporting surfaces are provided with humps situated transversely to the conveying direction of the conveyor. The drying unit according to the invention effectively reduces the moisture content of the conveyed paper tubes while maintaining their shape. Drying the tubes conveyed as a mass flow held by two supporting surfaces allows to avoid bending of the tubes which support one another or find support in the supporting surfaces of the conveyor. Furthermore, the stream of tubes can be directed at any angle during drying so the entire drying unit can be positioned at any angle. The object of the invention was shown in more detail in a preferred embodiment in a drawing in which: Fig. 1 shows a drying unit in vertical configuration,Fig. 2 shows a cross-section through the drying unit,Fig. 2a shows a fragment of the cross-section of Fig. 2,Fig. 3 shows a view of an outlet of the drying unit, andFig. 4 shows the drying unit in horizontal configuration. A drying unit 1 shown in Fig. 1 is adapted to dry paper tubes 4 during the conveyance of such tubes in a multilayer stream W. The drying unit 1 comprises a dryer 2 and a conveyor 3 adapted to convey the multilayer stream W of paper tubes 4. The paper tubes 4 in the stream W may be arranged in a regular manner (in a view as in Fig. 1 an arrangement similar to a honeycomb) as well as in an irregular manner. The dryer 2 shown in Fig. 1 comprises a drying chamber 5, an inlet 6, an outlet 7