Trockenhaube

Abstract

Drying hood (1) for a machine for producing or processing a fibrous web, in particular a paper or cardboard web, wherein the drying hood (1) comprises an insulated hood roof (2), characterized in that at least one, in particular several access openings (3) are provided in the hood roof (2)

Description

[0001] The invention relates to a drying hood for a machine for producing or processing a fibrous web, in particular a paper or board web. The invention particularly relates to a drying hood with an insulated hood roof provided with access openings to facilitate cleaning of the underlying false ceiling.

[0002] Drying hoods are state-of-the-art in modern paper machines and are described, for example, in documents DE 10 2021 115075, DE 10 2021 115076, and WO15 / 173080. They are used for thermal drying of the paper web and to minimize heat losses. In many designs, a so-called intermediate ceiling is provided within the drying hood, which contributes to the flow of the hood exhaust air and simultaneously serves as a drop protection against condensation.

[0003] A disadvantage of conventional drying hoods is that dust accumulates on the suspended ceiling, which can pose a significant fire hazard. However, cleaning these areas is complex because they are difficult to access from the existing walkways. In practice, this often requires extended machine downtime, which requires dismantling parts of the hood roof.

[0004] The invention is therefore based on the object of providing a drying hood that enables simplified and faster cleaning, particularly of the suspended ceiling, without requiring disassembly of the hood roof. At the same time, the thermal efficiency of the hood is maintained and condensation is prevented.

[0005] This object is achieved by a drying hood having the features of claim 1. Advantageous embodiments emerge from the subclaims.

[0006] The drying hood according to the invention comprises an insulated hood roof into which at least one, preferably several, access openings are integrated. These openings allow direct access to the interior of the drying hood, in particular to a suspended ceiling below, without having to dismantle the hood roof. This allows for significantly faster access to the interior of the drying hood.

[0007] The access openings are preferably designed to be closable, for example, by means of hinged or easily removable elements in the hood roof. This maintains the hood's thermal insulation during normal operation. The access opening, in particular the access flap, can be designed to open outwards.

[0008] In a preferred embodiment, the drying hood may include a false ceiling located inside the drying hood and positioned at a distance of usually less than 2 meters, preferably less than 1 meter, below the hood roof. This allows for a compact design and effective air flow.

[0009] The suspended ceiling serves primarily to even out the airflow during the extraction of the hood air and simultaneously provides protection against falling drops in the event of condensation. However, it is difficult to access from the walkways, which has made cleaning difficult.

[0010] The openings can be used, in particular, for cleaning purposes, such as dust extraction in the suspended ceiling area. This reduces the fire load and increases the operational safety of the system.

[0011] The access openings are preferably distributed so that every area of ​​the suspended ceiling can be reached with a cleaning device. Industrial vacuum cleaners typically have an effective radius of 3-4 m, so a maximum distance of 6-8 m, preferably ≤ 5 m, between adjacent openings is recommended. This allows the entire surface of the suspended ceiling to be reliably cleaned from the outside.

[0012] The hood roof is preferably constructed from a plurality of insulating panels, with at least one, or in particular several, of the insulating panels being equipped with an access opening. This enables a modular design and easy retrofitting of existing systems.

[0013] The frames of the inserts and panels are designed to prevent thermal bridges, e.g., through thermally separated profiles or insulating inserts. This prevents the formation of condensate inside the dryer hood, which in turn increases the service life of the components and improves paper quality.

[0014] The invention therefore offers the following advantages in particular: • Easier cleaning: The access openings allow targeted cleaning of the suspended ceiling, e.g. by suction with industrial vacuum cleaners. • Reduced downtime: Cleaning can be carried out during short maintenance windows without having to open the hood roof. • Improved safety: Regular removal of dust deposits reduces the fire load. • Thermal efficiency: Condensation is avoided by frame constructions that reduce cold bridges. • Modularity: The openings can be integrated into standard insulation panels, allowing for easy retrofitting. Example

[0015] In a preferred embodiment, a standard insulation panel is provided with a hinged insert integrated into the panel via an insulated frame. The insert can be opened without tools or removed completely, revealing the access opening. The openings are distributed in a grid pattern across the hood roof, with the spacing between adjacent openings being 4.5 m. The suspended ceiling is located 1.2 m below the hood roof and consists of perforated aluminum panels for air guidance. Cleaning is achieved by inserting a flexible suction hose with a radius of 3 m.

[0016] The invention is explained below with reference to figures. The invention is not limited to the embodiments shown in the figures.

[0017] The figures show in detail: Fig. 1: Drying hood according to the invention Fig. 2: Insulating panel of a drying hood according to another aspect of the invention Fig. 3 and Fig. 4 Hood roof of a drying hood according to another aspect of the invention

[0018] Fig. 1 shows a drying hood 1 according to one aspect of the invention in a schematic side view. The drying hood 1 comprises a hood roof 2, beneath which a suspended ceiling 5 is located. The suspended ceiling is arranged at a distance below the hood roof and serves to guide the air and as a drip guard. In this embodiment, several access openings 3 are provided, allowing cleaning of the suspended ceiling 5 without dismantling the hood roof 2. Drying cylinders 7 are located beneath the suspended ceiling 5 in the drying section 10.

[0019] Fig. Figure 2 shows a section of an embodiment of the drying hood 1 according to the invention, with an insulated hood roof 2, into which several access openings 3 are integrated. The access openings 3 are designed to be closable with access flaps 4. The flaps 4 open outward and allow direct access to the underlying suspended ceiling 5 without having to dismantle the hood roof 2. The suspended ceiling 5 is arranged at a distance of less than 2 m below the hood roof 2.

[0020] Fig. 3 and Fig. 4 show an enlarged section through an insulating panel 6 of a hood roof 2 with integrated access element. In Fig. 3 features an access flap 4 that opens outward. The access flap 4 is inserted into the panel 6 via a frame with reduced thermal bridges. The frame is thermally separated to prevent condensation. The flap 4 can be opened without tools or removed completely. Fig. 4 shows an embodiment in which the access opening 3 is closable, but does not have an access flap 4. Instead, the closure element can be lifted upwards out of the access opening 3, entirely or largely, without the use of tools.

[0021] Both variants provide easy access to the underlying suspended ceiling 5. List of reference symbols 1 drying hood 2 hood roof 3 Access opening 4 flap 5 False ceiling 6 insulation panels 7 drying cylinders 10 Dry section QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 115075

[0002] DE 10 2021 115076

[0002] WO 15 / 173080

[0002]

Claims

[1] Drying hood (1) for a machine for producing or processing a fibrous web, in particular a paper or cardboard web, wherein the drying hood (1) comprises an insulated hood roof (2), characterized by that at least one, in particular several access openings (3) are provided in the hood roof (2) [2] Drying hood (1) according to claim 1, characterized by that the at least one access opening (3) is designed to be closable. [3] Drying hood (1) according to claim 2, characterized by that the closable access opening (3) is designed as an access flap (4), wherein the access flap (4) can be opened in particular outwards. [4] Drying hood (1) according to one of the preceding claims, characterized by that the drying hood (1) further comprises an intermediate ceiling (5) which is provided in the interior of the drying hood (1) and which is arranged at a distance of less than 2 m, preferably less than 1 m, below the hood roof (2). [5] Drying hood (1) according to one of the preceding claims, characterized by that the drying hood (1) has a plurality of access openings (3) which are arranged in particular uniformly distributed over the hood roof (2), wherein the distance between two adjacent access openings (3) is less than 8m, in particular less than 5m. [6] Drying hood (1) according to one of the preceding claims, characterized by that the hood roof (2) is constructed from a plurality of insulating panels (6), wherein at least one, in particular several of the insulating panels (6) are equipped with an access opening (3).

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