EP2744935B1 - Domestic appliance, such as a washing machine, having a flow of liquid, such as suds, on a tubular heating body - Google Patents

Description

The invention relates to a domestic appliance in a preferred embodiment as a washing machine, washer dryer comprising the further features of the preamble of claim 1, a flow of a liquid, such as wash liquor, occurring during a washing process on a tubular heating element.

A tubular heater with individual heating pipes is the most frequently used type of heating in a domestic appliance, such as a washing machine or washer-dryer, in order to heat the washing liquor to a suitable temperature in a particular phase of the operation of the washing machine so that the detergent dissolved in the liquor is suitable Can have an effect. In addition to the effect of temperature and detergent, the laundry placed in a washing drum also has an effect on the movement acting on it, usually through a reversing movement of the washing drum in order to achieve an optimal cleaning result.

The tubular heater is housed in a washing machine with a substantially horizontally aligned axis of the washing drum below the washing drum but still inside a tub, which almost completely surrounds the washing drum, suitable and known fixing means for the tubular heater including its individual heating pipes being provided. The distance between the respective walls of the suds container in relation to the washing drum is kept very small so that the suds enclosed by the suds container are essentially inside the washing drum with its perforated drum casing. However, an exception must be made at the bottom of the tub, where the fixed tubular heater is located, in order to meet the space requirements of the tubular heater and for at least the same amount of liquid surrounding it, such as wash liquor. This space surrounding the tubular heating element within the tub is also referred to as a heating element pocket, such a heating element pocket often having an asymmetrical structure. For safety reasons, there is always liquid, such as lye, in the space surrounding the tubular heater, so that even when one starts Washing program, if the tub is not yet properly filled with alkali, the tubes of the tubular heater cannot burn out. The tubular heater is always surrounded by a lye sump, so to speak

A washing machine comprising a tubular heater, which has a structure corresponding to the above description, is for example from DE 44 35 095 A1 known.

Furthermore, in EP 1 857 584 A2 discloses a laundry treatment machine which comprises a tub, a laundry drum rotatably mounted therein and a plate heat exchanger. The plate heat exchanger is located in the area of the floor and is used to heat the liquid. Furthermore, a flap is arranged on the tub to allow liquid to flow past the heat exchanger in the washing mode and air in the drying mode.

In the case of constant washing processes, the disadvantage arises that the tubular heating element calcifies and lint often accumulates in the space surrounding the tubular heating element, which can pass through the drum holes at high speeds during washing operations, as well as reversing washing operations. These lint cannot be completely removed from this space during the washing-out of wash liquor, since a certain minimum volume of caustic must always remain in the space surrounding the tubular heating element. Unfortunately, therefore, the tubular heater does not only have an undesirable calcification, but also lint remains on the tubular heater with its heating pipes or lint deposits around the tubular heater, so that its efficiency and service life decrease.

It is also stated that domestic appliances, such as washing machines and washer-dryers, may have a radiant panel adjacent to the tubular heating element and its associated heating pipes for reasons of keeping the heat radiation away from a specific area. Such a radiant sheet is already in the DE 7023740 U discloses, this radiant sheet is not housed, as in the prior art to be taken into account in the starting point, in the area of the alkali sump next to the tubular heater and its heating pipes located there.

The object of the invention is therefore to provide a solution in relation to the area of the tubular heater and its heating pipes in a known domestic appliance such as a washing machine and washer dryer, after which the calcification in question and the lint deposition are avoided as far as possible.

According to the invention, it is provided that in a household appliance in a preferred embodiment as a washing machine, washer-dryer, with a washing drum which can be rotated about an essentially horizontally oriented axis and which is located in a tub which surrounds the washing drum essentially on all sides, with reference to a region between one in the circumferential direction extending jacket of the drum and a bottom wall of the tub, which is to be regarded as the bottom, there is a tubular heating element with heating tubes, the tubular heating element being surrounded by a liquid, such as wash liquor, at least when the domestic appliance is in operation, this liquid preferably being predetermined by the tubular heating element in a predetermined manner Operating phases can be heated, and a flow in the liquid is formed and, in some cases, a radiant panel can be used between the tubular heating element and the bottom of the tub. It is now provided that at least one flow-influencing region is formed between the tubular heating element and the bottom of the tub, which is designed such that it blocks part of the flow of the liquid in an area under the heating pipes and in an area in which the heating pipes are diverted, at least one area influencing the flow being formed on the bottom of the tub or on a radiant panel which is inserted between the tubular heating element and the bottom of the tub.

Due to the fact that during a treatment process in the household appliance, such as washing in a washing machine, by constantly lifting laundry items via drivers inside the drum, liquid or alkali escapes from the holes in the drum and causes a constant flow between the drum jacket and the tub which is also effective in the area of the heating pipes of the tubular heating element, it is achieved according to the invention that the flow in the area of the heating pipes is increased by a flow which would occur under the heating pipes without the measures according to the invention, is blocked. As a result, the lime and lint deposits in the area of the heating pipes of the tubular heater are effectively prevented.

It has been shown that the design of the radiant sheet according to the invention also means that the heating pipes can be flowed through with a total flow with increased flow speed. This means that the flow velocity of the liquid, such as lye, is increased compared to a situation without the design of the radiant sheet according to the invention. With increased wall shear stress between the alkali and the heating surface, the fluff and lime particles can be torn away or their deposition can be prevented.

With regard to the design of the radiant sheet in the sense of the invention, it has proven to be advantageous that the radiant sheet has at least one flow-influencing region in the immediate vicinity of at least one of the heating pipes.

A more specific further development in the sense of the invention consists in that on both sides of a hypothetical line of symmetry, which can be aligned in particular parallel to the axis of rotation of the drum, the radiant panel has the areas influencing the flow.

It has been found that there are alternatives as to how the flow-influencing region can be formed in the radiant panel according to the invention.

According to a first alternative, it is provided that the at least one flow-influencing region of the radiant sheet has a fold, such as in particular with the formation of a triangular cross section.

According to a second alternative, it is provided that the at least one flow-influencing area of the radiant sheet has a raised edge.

According to a third alternative, it is provided that the at least one flow-influencing region of the radiant sheet has a deep-drawing.

However, the invention is fundamentally designed in such a way that there are also other alternatives which become apparent when the teaching claimed in principle and the examples listed up to that point are taken into account.

The radiant panel as such can be detachably or non-detachably connected to the tub at the bottom area thereof. If a tub is made of plastic, the radiant panel can be added during its manufacturing process, such as injection molding, for an inseparable connection to the tub.

However, the invention also includes the fact that it is not necessary to use a separate radiant panel. The effects of a radiant sheet must then be simulated.

If it is provided that a tub is made of plastic, the bottom of this tub made of plastic should have a flow-influencing geometry, as can be achieved with a separately constructed radiant panel, preferably the plastic in the area of the replicated radiant panel is a high-temperature-resistant plastic. The latter measure is intended to ensure that the heat radiation, which can otherwise be oriented in a suitable manner so as not to damage the plastic of conventional design, now withstands this thermal load.

When designing the flow-influencing geometry in the bottom of the plastic suds container, it should be noted that it is necessary to provide at least one flow-influencing area in the immediate vicinity of at least one of the heating pipes.

It has been shown that it is expedient to form the flow-influencing regions on both sides of a hypothetical line of symmetry in the base of the tub, these regions having a configuration similar to that of alternative designs of a separately formed radiant sheet.

If it is provided that the suds container consists of a metallic material, such as sheet metal, the bottom of the suds container should have a flow-influencing geometry, as can also be achieved with a separately constructed jet plate.

In the case of a tub made of metallic material, it is also provided that the geometry influencing the flow in the bottom of this tub includes that at least one area affecting the flow is provided in the immediate vicinity of at least one of the heating pipes.

It has also been shown that it is advantageous if the flow-influencing regions can be formed on both sides of a hypothetical line of symmetry in the base of the tub, these regions having a configuration similar to that of alternative designs of a separately configured radiant sheet. However, it has to be taken into account, which is a certain limitation that no shape may be used in which an inadmissible opening of the tub made of metallic material would occur. In the event of a fault, however, no problems are to be expected with regard to the thermal radiation of a tubular heater and of its heating pipes.

Insofar as the invention is further developed by claims that are non-independent and referenced to the independent claim, it should be the case that an initially specified chain of relationships is not restrictive with respect to the total communicated Teaching can be seen insofar as other combinations of features of claims are found to be suitable and executable from the perspective of the person skilled in the art.

• Fig. 1 zeigt eine wesentliche Teil- Schnittansicht eines Hausgerätes, wie Waschmaschine betreffend eines Bereiches von Waschtrommel und Laugenbehälter in dem Heizungsrohre eines Rohrheizkörpers und ein erfindungsgemäßes Strahlblech sich befinden;
• Fig. 2 zeigt verschiedene Ausbildungen des erfindungsgemäßen Strahlblechs, wobei die strömungsbeeinflussenden Bereiche des Strahlblechs im Figurenteil a) durch eine Auffaltung, im Figurenteil b) durch eine Aufkantung und im Figurenteil c) durch einen Tiefzug erreicht werden.

The invention is described in more detail below schematically using exemplary embodiments. The same reference numerals show the same or comparable parts. The figures are first briefly explained.

• Fig. 1 shows an essential partial sectional view of a household appliance, such as a washing machine relating to an area of washing drum and tub in the heating pipes of a tubular heater and a radiant panel according to the invention;
• Fig. 2 shows various designs of the radiant sheet according to the invention, the flow-influencing areas of the radiant sheet in figure part a) being achieved by folding, in figure part b) by a bevel and in figure part c) by deep drawing.

In Fig. 1 are already entered in an essential sectional view of a household appliance, such as a washing machine, all the parts from which the invention is based. A washing drum 2 can thus be rotated about an essentially horizontally oriented axis 1 of the washing drum 2. In the selected sectional view, only the center of rotation of the axis is indicated in a manner that is not to scale, wherein a jacket 4 of the washing drum 2 is at a radius R from this center of rotation or axis 1. The axis of rotation is oriented essentially perpendicular to the plane of the drawing. The washing drum 2 is essentially surrounded on all sides by a tub 3 which can hold a liquid, such as washing liquor 8. Since the Fig. 1 is directed to the most important features of the invention, it is dispensed with the proportion of the wash liquor, which is located within the washing drum 2, with. For that is in Fig. 1 the main focus is on an area 6, which is located between the circumferentially extending jacket 4 of the washing drum 2 and a bottom wall 5 of the tub 3 to be regarded as the bottom 5. In this area 6 there is a tubular heating element with heating pipes 7 and 7 ', the tubular heating element with heating pipes 7 and 7' being surrounded by the previously named liquid, such as wash liquor 8, when the domestic appliance is operating here. This liquid, such as lye, is operated by the tubular heater with its heating tubes 7 and 7 ', as in predetermined operating phases. heated up. Since the washing drum 2 rotates during operation of the washing machine, a flow 9 forms in the liquid 8, which is initially represented by a large number of arrows. Between the tubes 7 and 7 'of the tubular heater and the bottom 5 of the tub 3, a radiant panel 10 is used, which is initially used during the operation of the radiator with the heating tubes 7 and 7' to radiate heat radiated from the tub, in particular the bottom 5 keep the tub 3 away, especially since it is usually economical to make the tub from plastic, which can be sensitive to heat.

The Fig. 1 also shows one of several drivers 11, which are located on the inside of the drum shell 4 of the laundry drum 2. Arrows 12 are entered in relation to the driver shown, which show the direction in which items of laundry placed in the laundry drum and the soapy water taken up are transported during operation of the washing machine. It can be seen that the flow 9 is directed opposite to the transport direction 12. By transporting the laundry via the carriers 11, the latter is constantly raised and possibly falls back again, depending on the rotational speed which the washing drum 2 is taking up. At the same time, the wash liquor is scooped by the movement of the laundry and the driver, which then emerges again from the drum and flows back in the gap between the tub shell and the drum, which causes the flow 9 of the wash liquor 8, which Fig. 1 illustrated.

It was found that with constant washing processes the disadvantage arises that pipes 7 and 7 'of the tubular heating element calcify and lint often accumulates in the space or area 5 surrounding the tubular heating element, which fluff away from the laundry when the laundry is moved vigorously during washing operations detach and step out through the drainage holes of the washing drum. These lint can combine with the lime released from the wash liquor, especially at higher temperatures, and can be deposited in very stable layers on the heating pipe of the radiator. The concentration of fluff, especially in area 5, is also favored by the fact that fluff cannot be completely removed from area 5 when washing liquor 8 is being pumped out. The lime and lint composite material accumulating on the heating pipe can lead to heat build-up during operation of the tubular heating element, reduce efficiency and reduce its service life.

In order to remedy these disadvantages, a special, unsigned path has been taken according to the invention. It was found that, compared to a conventional, smooth design, the radiant panel 10 is to be structured such that part of the flow 9 of the liquid 8 is to be blocked in an area 13 and 13 'under the heating pipes 7 and 7' and in an area , in which the heating pipes are located, must be diverted. In this respect, the Fig. 1 already a distribution of the flow 9, which was achieved with the measure according to the invention.

The special design of the radiant sheet 10 also means that the heating pipes 7 and 7 'can be flowed around with a total flow 9 with increased flow speed, to which the narrowed areas 13 and 13' contribute and which can also be explained after taking into account the relevant flow laws after the invention was created .

In order to achieve the narrowed areas 13 and 13 ', it is necessary for the radiant panel 10 to have at least one flow-influencing area 14 and 14' in the immediate vicinity of at least one of the heating pipes 7 and 7 '.

It has been found that on both sides of a hypothetical line of symmetry (which is not shown in the drawing), which is aligned in particular parallel to the axis of rotation 1 of the drum 2, the radiant panel 10 has the flow-influencing regions 14 and 14 '.

With regard to the implementation of the radiant sheet, it was found that there are various alternatives a) to c). These are in Fig. 2 shown in the figure parts a) to c).

In part a), a radiant panel is designated 20. Flow-influencing regions are provided which are formed by a respective unfolding 24 and 24 '. In this case, an almost triangular cross section is achieved, which is the representation of the radiant sheet 10 with the flow-influencing regions 14 and 14 'of the Fig. 1 can be assigned in an easily recognizable manner. It is also stated that the radiant panel 20 is shown only in the area that is important in the context of the invention with regard to its design becomes. Otherwise, it can be detachably connected to the bottom 5 of the layer container 3, such as by a screw connection or permanently, such as by riveting or gluing. If the tub 3 is made of plastic and there is an inseparable connection to the tub, it is also possible to connect the radiant panel 10 or 20 of the tub 3 in one manufacturing process, for example by injection molding. The plastic area of the tub then holds the radiant panel through adhesive forces.

In part b), a radiant panel is designated 30. Areas influencing the flow are provided which are formed by a respective upstand 34 and 34 'of the radiant sheet. When using this radiant sheet on the bottom 5 of the tub 3, a sharp transition is achieved, which leads to a locally very strong flow at a very high speed. The blasting off and the removal of lime particles and fluff is greatly promoted. Here too, the radiant panel 30 is only shown with regard to its design in the area that is important in the context of the invention. The possible mounting options are the same as for 2 a) described.

In part c) a radiant panel is designated 40. Flow-influencing regions are provided which are formed by a respective deep drawing 44 and 44 ', that is to say as a result by deep drawing. For example, the flow-influencing region can be formed by a respective bead. This is accompanied by a favorable shape for influencing the flow in the sense of the invention, so that the blasting off and the removal of lime particles and fluff can also be achieved to the desired extent. Here, too, the radiant panel 40 is shown with respect to its design only in the area important within the scope of the invention. The possible mounting options are the same as for 2 a) described.

In partial deviation from the in particular according to the 2 a) to c) The exemplary embodiments described can also be implemented in that a radiant panel is not used as such. Then the bottom 5 of the tub 3 must have a flow-influencing geometry which is equivalent to that used with the radiant sheet, for example in the configurations according to FIG 2 a) to 2 c) equals. It is possible to design the tub from plastic or from metallic material or from sheet metal. Will plastic as Starting material selected, the plastic material should be changed in the area of the heating pipes so that the thermal radiation emitted by the heating pipes in the event of a fault does not lead to serious functional damage to the plastic material of the tub. If a metallic material is selected, the simulation of a shape is similar to the variants of 2 a) to 2 c) make sure that no breaks or passages are formed in the base 5 of the tub. It is therefore the choice of the material of the tub to match the shaping options in order to achieve an optimal flow-influencing geometry.

Otherwise, it is noted that the flow-influencing region 14, 14 'described in all the embodiments of the invention or the flow-influencing structure present with it can extend over the entire length or also over part lengths of the tubular heating element with the heating tubes 7 and 7', in particular in this regard should arrive that areas of the tubular heating element that are particularly at risk of calcification are taken into account.

Reference list

1

Axis, turning center

2nd

Washing drum

3rd

Suds container

4th

Coat from washing drum

5

Bottom of the tub

6

Area with tubular heater

7.7 '

Heating pipes

8th

Wash liquor

9

flow

10th

Radiant sheet

11

Carrier

12th

Direction of transport

13, 13 '

Area under heating pipes

14, 14 '

Flow influencing area

20

Radiant sheet Fig. 2 , 1 . alternative

24, 24 '

Unfolding

30th

Radiant sheet 2, 2 . alternative

34, 34 '

Backsplash

40

Radiant sheet Fig. 2 , 3rd alternative

44, 44 '

Deep drawing

R

Distance radius of the jacket

Claims (12)

1. Household appliance, preferably configured as a washing machine or washer dryer with a laundry drum (2) that can be rotated about an essentially horizontally aligned axis (1) and is located in a tub (3) that encloses the laundry drum (2) essentially on all sides, wherein a tubular heating body with heating tubes (7, 7') is present in relation to a region between a casing (4) of the drum (2) extending in a circumferential direction and a lower wall of the tub (3) to be considered as the base (5), wherein the tubular heating body is surrounded by a liquid (8), such as wash liquor, at least during operation of the domestic appliance, wherein said liquid (8) can preferably be heated by the tubular heating body in predetermined operating phases and a flow (9) forms in the liquid (8), characterised in that at least one flow-influencing region (14, 14') is embodied between the tubular heating body and the base (5) of the tub (3) and is embodied so that it blocks a part of the flow of the liquid (8) in a region (13, 13') below the heating tubes (7, 7') and is diverted into a region in which the heating tubes (7, 7') are located, wherein the at least one flow-influencing region (14, 14') is embodied on the base (5) of the tub (3) or on a stream plate (10), which is inserted between the tubular heating body and the base (5) of the tub (3).
2. Household appliance according to claim 1, characterised in that the region (13, 13') below the heating tubes is tapered by the flow-influencing region (14, 14').
3. Household appliance according to claim 1 or 2, characterised in that the flow-influencing region (14, 14') is embodied in direct proximity to at least one of the heating tubes (7, 7').
4. Household appliance according to claim 3, characterised in that the stream plate (10) has the flow-influencing regions (14, 14') on both sides of a hypothetical line of symmetry, which can be aligned in particular parallel to the rotation axis of the drum (1).
5. Household appliance according to claim 3 or 4, characterised in that the at least one flow-influencing region (14, 14') of the stream plate (20) has an upward fold (24, 24'), in particular forming a triangular cross section.
6. Household appliance according to claim 3 or 4, characterised in that the at least one flow-influencing region of the stream plate (30) has an upward edge (34, 34').
7. Household appliance according to claim 3 or 4, characterised in that the at least one flow-influencing region of the stream plate (40) has a deep-drawn element (44, 44').
8. Household appliance according to claim 1, characterised in that the stream plate (10; 20; 30; 40) can be mounted in a releasable or non-releasable manner, optionally during production of the tub (3) made of plastic, on the base (5) of the tub.
9. Household appliance according to one of claims 1 to 3, characterised in that the tub (3) is made of plastic and the flow-influencing region (14, 14') on the base (5) of the tub (3) has a flow-influencing geometry, which corresponds to the geometry of the stream plate according to one of claims 5, 6, or 7, wherein the plastic in the region of the heating tubes (7, 7') is preferably plastic resistant to high temperatures.
10. Household appliance according to one of claims 1 to 3 or 9, characterised in that the flow-influencing regions (14, 14') are configured on both sides of a hypothetical line of symmetry in the base (5) of the tub (3), said regions having an embodiment which corresponds to the geometry of the stream plate according to one of claims 5, 6, or 7.
11. Household appliance according to one of claims 1 to 3, characterised in that the base of a tub (3) made of a metallic material, for example sheet metal, has a flow-influencing geometry (14, 14') which corresponds to the geometry of the stream plate according to one of claims 5, 6, or 7.
12. Household appliance according to claim 11, characterised in that the flow-influencing regions (14, 14') are configured on both sides of a hypothetical line of symmetry in the base of the tub, said regions having an embodiment which corresponds to the geometry of the stream plate according to one of claims 5, 6, or 7, but with the restriction that no impermissible opening of the tub made of metallic material can result.

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