Trough for a trough shortage

Abstract

A trough (1) for a trough ironer (100), comprising a trough plate (10) shaped into a circular segment with a flattening surface (11) that can be brought into contact with the laundry to be treated, and comprising a cover plate (12) on the outer surface (13) of the curved trough plate (10), which is welded to the trough plate (10) over the planar extent of the trough plate (10) by a plurality of spot welds (14) and is deformed by internal high-pressure forming in such a way that a flow space for flow of a heat transfer medium is formed between the trough plate (10) and the deformed cover plate (12), characterized in that the trough plate (10) and the cover plate (12) are made of a heat-resistant structural steel.

Description

[0001] The invention relates to a trough for a trough ironer, comprising a trough plate shaped like a circular segment, with an ironing surface that is brought into contact with the laundry to be treated. The laundry is usually both finally dried and ironed using such a trough. For this purpose, the trough is heated during operation, with the heat being introduced into the trough plate using a heat transfer medium. For this purpose, a cover plate is applied to the outer surface of the trough plate. This cover plate, viewed over the entire trough, has the same curvature as the trough plate, but is deformed into a so-called pillow plate using an internal high-pressure forming process, so that fluid spaces are created between the trough plate and the cover plate, through which fluid oil can flow, for example, as a heat transfer medium. The trough plate, on the other hand, is not deformed by the internal high-pressure forming process due to its significantly greater thickness.For this purpose, the cover plate is welded to the trough plate over its flat extension with a large number of welding points so that the heat transfer medium can flow through the space between the cover plate and the trough plate. STATE OF THE ART

[0002] For example, such a trough is known from EP 1 120 488 A2. The trough's basic structure consists of a trough plate with an inner ironing surface, into which a mangle roller is inserted, allowing the laundry to be both dried and smoothed via the circumferential gap between the mangle roller and the ironing surface of the trough plate. The cover plate, which has been formed into a pillow plate, is arranged on the outer surface of the trough plate, creating a flow space for the flow of a heat transfer medium.

[0003] Such troughs for trough ironers are known to be made of stainless steel, so that at least the trough plate is made of a stainless steel material. For example, see EP 0 855 459 A1.

[0004] In contrast, WO 2010 / 037401 A1 teaches that the trough plate is made of a low-alloy steel, while the cover plate is made of stainless steel. Selecting stainless steel for the cover plate is said to offer the advantage of improved formability, while selecting a trough plate made of non-alloyed or low-alloyed steel as the material offers good thermal conductivity properties, ensuring uniform heating of the trough plate, particularly over the circumference and length of the trough mangle.

[0005] Disadvantages of the material combinations include the welding behavior of the two materials, the different expansion behavior, and the price of stainless steel sheets, particularly for the provision of the usually thicker trough plate relative to the thickness of the cover plate. However, if the trough plate is made of stainless steel, the thermal conductivity is poorer and thus the temperature distribution is uneven within the trough, for example, with a higher temperature in the area of ​​the incoming heat transfer medium compared to the outgoing heat transfer medium. While the cover plate does not need to have a particularly high thermal conductivity to achieve uniform temperature distribution within the trough, it can also contribute to this. DISCLOSURE OF THE INVENTION

[0006] The object of the invention is to improve the trough for a trough plate which is easy to manufacture, low in cost and enables a good even heat distribution over the entire contact surface for the laundry to be treated.

[0007] This object is achieved based on a trough according to the preamble of claim 1 in conjunction with the characterizing features. The same applies to the subordinate claim 10. Advantageous developments of the invention are specified in the dependent claims.

[0008] The invention includes the technical teaching that the trough plate and the cover plate are formed from a heat-resistant structural steel.

[0009] Heat-resistant structural steels exhibit high thermal conductivity. At operating temperatures of the troughs of, for example, approximately 150°C to 200°C, the thermal conductivity of heat-resistant structural steel is approximately 50W / m*K, while stainless steel has a thermal conductivity of only about 30% of that of heat-resistant structural steels. Thus, with heat-resistant structural steel, a high overall thermal conductivity can be achieved for both the trough plate and the cover plate, ensuring even heat distribution throughout the trough. The cover plate can be advantageously welded to the trough plate via the numerous welding points, as heat-resistant structural steels generally offer good weldability. Furthermore, the inventive selection of materials results in low costs, significantly lower than those of stainless steels.

[0010] The heat-resistant structural steel of the trough plate and cover plate can be particularly advantageously made from H2 grade boiler steel. Boiler steels, boiler plates, or so-called pressure vessel steels with H2 grade contain low alloys of carbon, chromium, copper, manganese, molybdenum, nickel, niobium, phosphorus, sulfur, silicon, nitrogen, titanium, and / or vanadium. Boiler steels of this grade, in particular, exhibit high strength even at higher temperatures, such as those used in heated trough ironers.

[0011] The yield strength Rp0.2 for a boiler steel grade H2 is approximately 200 MPa at the temperatures mentioned, whereas stainless steel only achieves a yield strength Rp0.2 of 130 MPa to 140 MPa at the same temperatures. This results in increased rigidity of the troughs, even with thinner trough plates. The heat-resistant structural steel of the trough plate and the cover plate can be made of steel 1.0425, also known as P265GH. Within the scope of the specified heat-resistant structural steels, the exact material specifications of the trough plate and the cover plate may differ from those of the trough plate, although they are preferably identical.

[0012] For the purposes of the invention, the thickness of both the trough plate and the cover plate also plays a role. The selected plate thicknesses of both the trough plate and the cover plate can be matched to the strength properties of the heat-resistant structural steel. It has proven advantageous for the plate thickness of the trough plate to be 6 mm to 15 mm, preferably 8 mm to 13 mm, more preferably 9 mm to 12 mm and in particular 10 mm. The plate thickness of the cover plate can be 1 mm to 4 mm, preferably 1.5 mm to 3.5 mm, more preferably 2 mm to 3.2 mm and particularly preferably 3 mm, preferably paired with the thickness of the trough plate of 10 mm. Thus, the trough plate and the cover plate can be designed free of stiffening frames, and the dimensional stability of the trough can be created simply by the plate pairing of trough plate and cover plate with the preferred plate thicknesses as described above.

[0013] Due to the good weldability of the heat-resistant structural steel according to the invention for both the trough plate and the cover plate, a laser welding process is suitable for producing the plurality of weld points. In addition, the trough plate and the cover plate can have a circumferential edge weld seam, which is also produced by laser welding. The weld points over the planar extent of the trough plate or the cover plate can preferably have a regular grid. The weld point spacing in the grid of the weld points can be, for example, 30 mm to 70 mm, preferably 40 mm to 60 mm, and more preferably 52 mm to 58 mm. The row and column-shaped matrix arrangement of the weld points can be rotated by 45° with respect to the circumferential direction or the longitudinal direction of the trough.

[0014] In this case, the connection points between the cover plate and the trough plate are referred to as weld points, which are arranged in a grid pattern and are therefore spaced apart from one another. The weld points themselves can have a structure; for example, the weld points can form weld squares, weld crosses, weld polygons, or weld rings, so that ring welds can have a ring diameter of 8 mm to 13 mm, preferably 9 mm to 12 mm, and more preferably 11 mm. For example, ring welds with a diameter of 10 mm to 12 mm can be harmonized with a grid of weld points with a grid spacing of 55 mm. Ring welds are preferred because there are no corner areas that would experience excessive stress during hydroforming.

[0015] The invention is further directed to a trough ironer with a trough, comprising a trough plate shaped into a circular segment with an ironing surface that is brought into contact with the laundry to be treated, and comprising a cover plate on the outer surface of the curved trough plate, which is welded to the trough plate with a plurality of weld points over the flat extent of the trough plate and has been deformed by internal high-pressure forming such that a flow space for the flow of a heat transfer medium is formed between the trough plate and the deformed cover plate, wherein the trough plate and the cover plate are formed from a heat-resistant structural steel. The features and associated advantages in connection with the trough listed above are taken into account in the same way for the trough ironer according to the invention. PREFERRED EMBODIMENT OF THE INVENTION

[0016] Further measures improving the invention are described in more detail below, together with the description of a preferred embodiment of the invention, with reference to the figures. It shows: Fig. 1 a schematic view of a trough mangle with two troughs as an example, Fig. 2 a perspective view of a trough with a trough plate and an outside cover plate and Fig. 3 a cross-sectional view through the trough with an inserted trough roller.

[0017] Fig. 1 shows a schematic view of a flatwork ironer 100 with, for example, two flatwork ironers 1, each containing a flatwork roller 15. The flatwork ironers 1 are accommodated in a frame 16 of the flatwork ironer 100, with a bridge 18 for transferring the laundry being inserted between the two flatwork ironers 1.

[0018] The trough 1 has a trough plate 10, which forms the basic structure of the trough 1, since the trough plate 10 has a greater thickness, for example, 10 mm. The trough plate 10, made of heat-resistant structural steel, thus determines the shape of the trough 1, which is shaped into a circular segment, for example, or approximately a semicircle, so that the mangle roller 15 is enclosed in an approximately semicircular manner as shown, wherein the above-described circular segment of the trough plate 10 has a length of, for example, 2 m to 5 m, preferably 3 m to 4 m, and particularly preferably 3.5 m. The diameter of the circular segment and thus also of the trough plate 10 can be, for example, 0.5 m, while the mangle roller 15 has a slightly smaller diameter.

[0019] The trough plate 10 has a flattening surface 11 for contact with the laundry, which faces inward toward the ironer roller 15. A mangle gap is created between the flattening surface 11 and the outer peripheral surface of the ironer roller 15, through which the laundry to be treated is passed. For this purpose, the ironer roller 15 is set in rotation, and the interior of the ironer roller 15 is connected to a suction air system to extract warm, moist air and thus dry the laundry.

[0020] To heat the trough plate 10, it has a cover plate 12 applied to its outer surface 13, which is formed according to the pillow-plate principle using an internal high-pressure forming process. This creates a fluid chamber 17 in the space between the trough plate 10 and the cover plate 12, through which, for example, a hot heat transfer medium can flow.

[0021] The Fig. Figure 2 shows the trough 1 with the trough plate 10 visible on the inside, which forms the flattening surface 11 facing inwards. The cover plate 12 is applied to the outer surface 13 of the trough plate 10 and welded via a plurality of welding points 14. If the trough plate 10 and the cover plate 12 are welded via the plurality of welding points 14, the cover plate 12 is subsequently bulged in the areas between the welding points 14 via internal high-pressure forming, whereby the Fig. 1 is formed. This pillow-plate principle enables the direct flow of a heat transfer medium onto the trough plate 10. During internal high-pressure forming, the trough plate 10 is not deformed due to the considerably greater material thickness compared to the cover plate 12, and only the cover plate 12 assumes the pillow structure. The distance between the weld points 14, represented by the weld point distance A, is approximately between 52 mm and 58 mm, for example.

[0022] Fig.3 finally shows the trough 1 with the inserted mangle roller 15 comprising the trough plate 10 and the cover plate 12, wherein the plurality of weld points 14 shows that the bulge can be created between them in order to create the fluid space 17 between the trough plate 10 and the cover plate 12. The detail X shows an enlarged view of a weld point 14 with the cover plate 12 bulging laterally above the trough plate 10. The thickness of the trough plate 10, shown with the plate thickness D, is, for example, 10 mm, wherein the thickness of the cover plate 12, shown as plate thickness d, is approximately 3 mm.

[0023] The invention is not limited in its implementation to the preferred embodiment described above. Rather, a number of variants are conceivable, which utilize the presented solution even in fundamentally different embodiments. All features and / or advantages apparent from the claims, the description, or the drawings, including structural details or spatial arrangements, may be essential to the invention both individually and in a wide variety of combinations. List of reference symbols: 1 trough 10 trough plate 11 Flat surface 12 Cover plate 13 Exterior surface 14 welding point 15 mangle roller 16 frames 17 Fluid chamber 18 Bridge 100 trough mangle D Plate thickness trough plate d Plate thickness cover plate A Weld point distance 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] EP 1 120 488 A2

[0002] EP 0 855 459 A1

[0003] WO 2010 / 037401 A1

[0004]

Claims

[1] Trough (1) for a trough ironer (100), comprising a trough plate (10) shaped into a circular segment with an ironing surface (11) that can be brought into contact with the laundry to be treated, and comprising a cover plate (12) on the outer surface (13) of the curved trough plate (10), which is welded to the trough plate (10) with a plurality of welding points (14) over the planar extent of the trough plate (10) and is deformed by internal high-pressure forming such that a flow space for the flow of a heat transfer medium is formed between the trough plate (10) and the deformed cover plate (12), characterized by that the trough plate (10) and the cover plate (12) are made of a heat-resistant structural steel. [2] Trough (1) according to claim 1, characterized by that the heat-resistant structural steel of the trough plate (10) and the cover plate (12) is a boiler steel of grade H2. [3] Trough (1) according to claim 1 or 2, characterized bythat the trough plate (10) and the cover plate (12) are made of heat-resistant structural steel 1.0425 and / or P265GH. [4] Trough (1) according to one of claims 1 to 3, characterized by that the plate thickness (D) of the trough plate (10) is 6mm to 15mm and / or 8mm to 13mm and / or 9mm to 12mm and / or 10mm. [5] Trough (1) according to one of the preceding claims, characterized by that the plate thickness (d) of the cover plate (12) is 1mm to 4mm and / or 1.5mm to 3.5mm and / or 2mm to 3.2mm and / or 3mm. [6] Trough (1) according to one of the preceding claims, characterized by that the trough plate (10) and the cover plate (12) are designed free of stiffening frames and the dimensional stability of the trough (1) is created by the plate pairing of trough plate (10) and cover plate (12). [7] Trough (1) according to one of the preceding claims, characterized bythat the plurality of welding points (14) are produced by means of laser welders and that the trough plate (10) and the cover plate (12) have a predominantly circumferential edge weld seam. [8] Trough (1) according to one of the preceding claims, characterized by that the welding points (14) are distributed in a preferably regular grid on the planar extension of the trough plate (10) or the cover plate (12) and have a distance of 30 mm to 70 mm and / or from 40 mm to 60 mm and / or from 52 mm to 58 mm. [9] Trough (1) according to one of the preceding claims, characterized by that the welding points (14) have a ring weld with a ring diameter (R) of 8mm to 13mm and / or of 9mm to 12mm and / or of 11mm. [10] Trough ironer (100) with a trough (1), comprising a trough plate (10) shaped into a circular segment with an ironing surface (11) which can be brought into contact with the laundry to be treated, and comprising a cover plate (12) on the outer surface (13) of the curved trough plate (10), which is welded to the trough plate (10) with a plurality of welding points (14) over the planar extent of the trough plate (10) and is deformed by internal high-pressure forming such that a flow space for the flow of a heat transfer medium is formed between the trough plate (10) and the deformed cover plate (12), characterized by that the trough plate (10) and the cover plate (12) are made of a heat-resistant structural steel. [11] Trough mangle (100) according to claim 10 with a trough (1) according to one of claims 2 to 9.

Images