Drying apparatus and dryer for a textile web comprising an improved device for introducing heat

Abstract

A drying apparatus includes a dryer for a textile web. The dryer includes a drying chamber and at least one air-permeable drum arranged to rotate in the drying chamber. The textile web is guidable over a partial section of the circumference of the drum and heated drying air is flowable through the textile web. The dryer further includes a device to introduce heat for heating up the drying air. The device includes an internal hot gas source and an external hot gas source. The internal hot gas source is a component of the dryer and the external hot gas source is arranged peripherally to the dryer and includes a hot gas line connected at least indirectly to the dryer.

Claims

1. A drying apparatus, comprising: a dryer for a textile web, the dryer including a drying chamber and at least one air-permeable drum arranged to rotate in the drying chamber, wherein the textile web is guidable over a partial section of a circumference of the drum and heated drying air from the drying chamber is flowable through the textile web; a device to introduce heat for heating up the drying air, the device comprising an internal hot gas source and an external hot gas source, wherein the internal hot gas source is a component of the dryer and the external hot gas source is arranged peripherally to the dryer and includes a hot gas line connected at least indirectly to the dryer; a first heat exchanger adapted to release heat to the drying air; and a preheat exchanger and a fluid line coupling the preheat exchanger to the first heat exchanger, wherein the hot gas line of the external hot gas source extends into the preheat exchanger and transfers heat to a heating fluid in the fluid line.

2. The drying apparatus according to claim 1, wherein the internal hot gas source includes a gas blower burner arranged in or on the dryer.

3. The drying apparatus according to claim 1, wherein the external hot gas source includes a cogeneration plant which transfers via the hot gas line at least indirectly heat into the drying chamber.

4. The drying apparatus according to claim 1, further including a control unit coupled to the internal hot gas source and to the external hot gas source and configured to control the internal hot gas source and the external hot gas source.

5. The drying apparatus according to claim 4, wherein the control unit is configured to control the internal and external hot gas sources so that the external hot gas source serves as a basic heat supply for the dryer and the internal hot gas source functions to control the temperature of the drying air.

6. The drying apparatus according to claim 1, further including a fresh air heat exchanger coupled to the external hot gas source and to the drying chamber, wherein hot gas from the external hot gas source is flowable through the fresh air heat exchanger, wherein the fresh air heat exchanger is arranged downstream of the preheat exchanger and fresh air entering the drying chamber is heatable by the fresh air heat exchanger prior to entering the drying chamber.

7. The drying apparatus according to claim 4, further including at least one measuring element to measure moisture in the drying air in the drying chamber, wherein the control unit is coupled to the measuring element to read moisture values out of the measuring element and to actuate the internal and external hot gas sources in dependence on the moisture values.

8. A dryer for a textile web, comprising: a drying chamber; at least one air-permeable drum arranged to rotate in the drying chamber, wherein the textile web is guidable over at least a partial circumference of the drum and heated drying air is flowable through the textile web; an internal hot gas source to heat up the drying air; a first heat exchanger by which heat is releasable to the drying air; and a preheat exchanger and a fluid line coupling the preheat exchanger to the first heat exchanger, wherein a hot gas line of an external hot gas source extends into the preheat exchanger and transfers heat to a heating fluid in the fluid line.

9. The dryer according to claim 8, further including a control unit arranged to control the internal hot gas source and the external hot gas source.

10. The dryer according to claim 9, wherein the control unit actuates the hot gas sources so that the external hot gas source supplies heat to the dryer and the internal hot gas source functions to regulate a temperature of the drying air.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional measures to improve the invention are described in further detail in the following with the description with the aid of the Figures, in which:

(2) FIG. 1 is a schematic view of a drying apparatus with a dryer and an external hot gas source which comprises a cogeneration plant;

(3) FIG. 2 is a variant of the exemplary embodiment according to FIG. 1 with a first heat exchanger in the dryer, and

(4) FIG. 3 is a different variant of the dryer according to FIG. 2, wherein a preheat exchanger is installed, which forms an internal heat exchanging loop together with the first heat exchanger.

DETAILED DESCRIPTION OF THE INVENTION

(5) FIGS. 1, 2 and 3 respectively show a drying apparatus with a dryer 100 for drying a textile web 1. The dryer 100 comprises a housing 27 with therein formed drying chamber 10. Shown are two air-permeable drums 11 which are arranged rotating in the drying chamber 10. The textile web 1 initially wraps around the first drum 11 and then the second drum 11. A roller 28 functions as intake roller and to supply of the textile web 1 to the first drum 11 while a discharge roller 29 is used to discharge the textile web 1 from the second drum 11.

(6) Several arrows show that drying air 12 can flow through the textile web 1 arranged around the outside circumference of the drum 11, so that the drying air collects on the inside of the drum 11 from which it is suctioned out with devices not shown further herein.

(7) A portion of the drying air 12 is released as exhaust air 30 via an exhaust-air device 31 from the drying chamber 10 while fresh air 24 is supplied to the drying chamber 10, which then mixes with the drying air 12.

(8) A first device 13 for introducing heat takes the form of an internal hot gas source 15, wherein for the exemplary embodiments the internal hot gas source 15 is a gas blower burner 18.

(9) The drying apparatus furthermore comprises an external hot gas source 16 which forms an additional device 14 for introducing heat. The external hot gas source 16 may comprises a cogeneration plant 19. Hot gas flows from the cogeneration plant 19 via a hot gas line 17, wherein the heat from the cogeneration plant 19 is supplied directly or indirectly to the drying air 12 in the drying chamber 10.

(10) FIG. 1 shows an exemplary embodiment in which the hot gas line 17 is supplied to a mixing module 21 in the drying chamber 10. The hot gas from the internal hot gas source 15 as well as the hot gas from the external hot gas source 16 is supplied via the hot gas line 17 to the mixing module 21. The hot gases are mixed in the mixing module and are then released to the drying air 12.

(11) The embodiment according to FIG. 1 furthermore shows a control unit 20 which is connected to the cogeneration plant 19 and the gas blower burner 18, so as to activate these accordingly. Also shown is a connection between the control unit 20 and the mixing module 21, designed to activate the mixing module 21 such that the highest possible energy amount is contributed by the external hot gas source 16 to the drying air 12 and so that the internal hot gas source 15 is operated at the lowest possible energy level.

(12) A measuring element 26 for measuring the moisture may be connected to the control unit 20 to measure the degree of moisture in the drying air 12 in order to correspondingly activate the internal and external hot gas sources 15 and 16, and in particular the mixing module 21.

(13) FIG. 2 shows a modified embodiment compared to the embodiment of FIG. 1, wherein hot gas from the cogeneration plant 19 is supplied via the hot gas line 17 to a first heat exchanger 22. The drying air 12 is heated via the first heat exchanger 22, wherein the introduced heat is initially supplied to the mixing module 21.

(14) The hot gas line extends again out of the first heat exchanger 22 as hot gas line 17 which may lead to a fresh air heat exchanger 23 for preheating the fresh air 24 that enters the drying chamber 10. This results in an even better use of the amount of heat energy supplied by the cogeneration plant 19.

(15) FIG. 3 shows the exemplary embodiment according to FIG. 2 with an additional heat exchanger forming a preheat exchanger 25.

(16) The heat from the hot gas in the line 17, coming from the cogeneration plant 19, is transferred to the preheat exchanger 25, which exchanges the heat for a heating fluid, such as a thermal heating oil, in a fluid line 32. Once the hot gas from the hot gas line 17 moves through, it continues in the hot gas line 17 line to the fresh air heat exchanger 23 to preheat the fresh air 24 entering the drying chamber 10, as previously described in connection with FIG. 2. The preheat exchanger 25 can be arranged near the cogeneration plant 19, in particular it is possible for the preheat exchanger 25 to form a single structural unit with the external hot air source 16, resulting in the advantage of a better transportability of the heat in a heating fluid in the fluid line 32, to be supplied to the heat exchanger 22.

(17) The control unit 20 and moisture measuring element 26, shown and described in connection with FIG. 1, are shown installed in a similar manner for the embodiments according to FIG. 2 and FIG. 3. In particular, it is possible to use the control unit 20 to activate the preheat exchanger 25 shown in FIG. 3 and/or the fresh air heat exchanger 23 shown in FIGS. 2 and 3, for example, to control the amount of the respective energy transfer or energy introduction.

(18) It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and that the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.