The invention relates to a laundry treatment apparatus having a heat pump system, in particular the invention relates to a heat pump tumble dryer or a washing machine having a dryer function (washer dryer).

EP 2 341183 A1 discloses a dryer comprising a heat exchanger for cooling process air. A front portion of the heat exchanger is cleaned by a liquid spray from a pipe which is connected to a liquid collection chamber arranged below the heat exchanger. Condensate generated at the heat exchanger as well as liquid supplied to the front portion of the heat exchanger is collected in the liquid collection chamber. A filter is arranged in the collection chamber in the region of the collection chamber which is between the front portion of the heat exchanger and a rear portion. A cleaning pump for pumping liquid through the pipe to the heat exchanger for cleaning is arranged in the collector chamber below a rear portion of the heat exchanger. The liquid used for cleaning the heat exchanger washes off fluff from the heat exchanger surface and the fluff is collected in the collection chamber. By activating the cleaning pump liquid is pumped from a front portion of the collection chamber (below the front portion of the heat exchanger) through the filter to the rear portion, such that only filtered liquid is conveyed to the heat exchanger for cleaning. By activating a draining pump which is fluidly connected to the front portion of the collection chamber the liquid flow through the filter is reversed, whereby collected fluff is washed from the filter and drained from the collection chamber.

It is an object of the invention to provide a dryer or washer dryer with low production and maintenance costs.

The invention is defined in claim 1, Particular embodiments are set out in the dependent claims.

According to claim 1 a heat pump tumble dryer or washer dryer having a dryer function is provided. In the following the dryer or washer dryer is denoted as treatment or laundry treatment apparatus for simplicity. The treatment apparatus comprises a laundry treatment chamber for treating laundry using process air, i.e. a laundry drum, and a process air circuit or loop for circulating the process air through the treatment chamber. A heat pump system of the treatment apparatus comprises a first heat exchanger arranged in the process air circuit for cooling the process air and a second heat exchanger arranged in the process air circuit for heating the process air. Cleaning means are adapted to provide cleaning liquid to the first heat exchanger for cleaning a portion or at least a portion of the first heat exchanger surface, i.e. fluff generated during a drying process is collected on the first heat exchangers surface, in particular a front portion of the first heat exchanger which is passed by process air first. Collected fluff on the first heat exchanger surface may affect adversely the heat exchanger performance. This is prevented by the cleaning means which washes off collected fluff from the first heat exchanger. A liquid collector is assigned to the first heat exchanger and is adapted to collect liquid from the first heat exchanger.

The liquid collector comprises at least two compartments, wherein a first compartment is adapted to collect condensate generated at the first heat exchanger and a second compartment is adapted to collect the cleaning liquid provided to the first heat exchanger by the cleaning means, i.e. the first compartment collects reusable 'clean' liquid, i.e. condensate, and the second compartment collects 'dirty' or contaminated liquid, i.e. liquid with fluff, which may be discharged via the process air coming from the laundry treatment chamber. The at least two compartments are separated from each other, i.e. the at least two compartments are spatially separated, for example by a partition wall, such that clean liquid and dirty liquid are collected separately. The liquid collected in the second compartment may include a small portion of the liquid condensed at the first heat exchanger. Liquid collected in first compartment is or is essentially condensate but may include a small (spilling) fraction of the cleaning liquid. In other words clean and dirty liquid are not or are essentially not mixed, such that always clean liquid is provided, which might be reused for cleaning the first heat exchanger with the cleaning means. Preferably a separation means is provided such that the liquid collected in the second compartment can not flow or leak to the first compartment.

Preferably the first and second compartments are separated from each other such that there is no liquid communication between the liquid in the first compartment and the liquid in the second compartment. Thus in operation the two compartments have liquid levels that are independent of each other. The absolute liquid levels (e.g. in relation to a horizontal plane taken as a reference, for example the floor where the machine is installed) in the compartments may be different of each other according to the operation state of the tumble dryer or washer dryer. In particular, during an initial phase of the drying cycle, the first compartment collects the water condensed at the evaporator and the liquid level increases accordingly, whereas the second compartment is substantially empty during said initial phase and the liquid level inside the second compartment increases only when the evaporator cleaning operation is activated, which operation is performed after said initial phase since condensed water needs to be accumulated in the first compartment.

At least one of the first compartment and second compartment may extend at least partially below the first heat exchanger, such that condensate is easily collected in the first compartment and/or dirty liquid is easily collected in the second compartment by flowing down from the heat exchanger into the respective compartment. In particular no liquid filter means is provided for filtering the liquid collected in the first compartment or no liquid filter is arranged in a cleaning liquid path between the first compartment and the first heat exchanger. In contrast to EP 2 341 183 A1 the above described treatment apparatus does not need a filter means for the evaporator cleaning liquid path to provide clean liquid e.g. for cleaning the first heat exchanger or for collecting in a removable container for ironing. As the above treatment apparatus does not need a filter means, less components have to be assembled, and in particular no filter means has to be maintained or cleaned. In other words a treatment apparatus is provided with low production and maintenance costs.

Preferably the cleaning means comprises a conveying means adapted to convey liquid from the first compartment to the first heat exchanger, e.g. the conveying means may comprise a first pump for pumping clean liquid from the first compartment to a front portion of the first heat exchanger. Alternatively the conveying means may comprise a tank for storing clean liquid, which is arranged above or higher than the first heat exchanger, and a valve which is opened during a cleaning phase for cleaning the first heat exchangers, such that clean liquid is supplied or conveyed to the first heat exchanger by means of gravity.

According to an embodiment at least one of the first compartment and the second compartment is at least partially arranged below the second heat exchanger, For example when both heat exchangers are arranged in a base unit of the treatment apparatus at least one of or both of the compartments, i.e. the liquid collectors, may be arranged at least partially below the second heat exchanger in a space-saving manner. For example the liquid collector is at least partially formed integrally with a base unit of the treatment apparatus, such that the number of assembly parts is reduced, i.e. the treatment apparatus is easy to assemble.

Preferably the cleaning means comprises a first pump controlled by a control unit of the treatment apparatus for pumping liquid from the first compartment to the first heat exchanger or to an intermediate tank or container from where it is supplied to the cleaning means. Thus excess (clean) liquid may be pumped to the intermediate tank for later use. i.e. for cleaning the first heat exchanger. According to an embodiment the intermediate tank is removable, such that the collected clean liquid may be used e.g. for ironing.

According to an embodiment the treatment apparatus comprises a second pump controlled by a control unit of the treatment apparatus for pumping liquid from the second compartment to an extractable container or to the outside of the treatment apparatus. Thus excess dirty or contaminated liquid may be removed from the treatment apparatus, i.e. from the second compartment. For example a liquid level detector connected to the control unit is arranged in the first and/or second compartment. When a maximum liquid level is reached in the first/second compartment the control unit activates the first/second pump to remove excess liquid.

Preferably the first compartment comprises a first sump which is in fluid connection with the first compartment or which is part of the first compartment, wherein the first sump is arranged at a rear portion of a basement of the treatment apparatus and wherein the first pump is arranged at or in the first sump for pumping liquid from the first sump, e.g. to the first heat exchanger. Additionally or alternatively the second compartment comprises a second sump which is in fluid connection with the second compartment or which is part of the second compartment, wherein the second sump is arranged at a rear portion of the treatment apparatus basement and wherein the second pump is arranged at or in the second sump for pumping liquid from the second sump, e.g. to the outside of the treatment apparatus. The treatment apparatus basement is preferably formed by a two-part base unit comprising an upper shell and a lower shell. Preferably at least a portion of a bottom or base section of the first compartment and additionally or alternatively of the second compartment has an inclined slope for guiding the collected liquid towards the rear part of the basement. I.e. the inclined bottom section guides the liquid towards the first and additionally or alternatively towards the second sump.

According to an embodiment the cleaning means is adapted to supply the cleaning liquid to a front or side portion or to a front or side surface of the first heat exchanger. The front surface is located where the process air coming from the laundry treatment chamber along the process air channel hits the first heat exchanger first. I.e. the portion or surface of the heat exchanger where most of or all of the fluff carried by the process air is collected Thus it is provided that the cleaning means washes off all fluff from the heat exchanger such that the heat exchanger is thoroughly cleaned

Preferably the cleaning means is adapted to supply liquid to an upper portion of the first heat exchanger from face. I.e. liquid is supplied to an upper portion, such that it subsequently flows down the heat exchanger from top to bottom, whereby fluff is washed off. Alternatively the cleaning means is adapted to supply liquid to the entire or essentially the entire front surface of the first heat exchanger perpendicular to the process air flow, such that the complete front surface or portion is cleaned with a liquid spray of clean liquid.

The first compartment may be at least partially arranged below a middle and rear portion of the first heat exchanger, Thus gravity assists clean liquid (condensate) flowing towards the first compartment as it is arranged below the portion of the first heat exchanger where condensate is generated. Further, as the liquid for cleaning the heat exchanger is distributed across a front surface or front portion of the first heat exchanger, the dirty (cleaning) liquid is prevented from flowing into the first compartment. According to another example the first compartment is arranged in a space-saving manner below at least a portion of the second heat exchanger and a middle/rear portion of the first heat exchanger,

Preferably the second compartment is at least partially arranged below a front portion of the first heat exchangers which is cleaned by the cleaning liquid, such that liquid flowing down from the heat exchanger carrying fluff is safely or efficiently collected in the second compartment.

The second compartment may extend or essentially extend across the width of the first heat exchanger perpendicular to the process air flow, e.g. when the second compartment is arranged at least partially below the heat exchanger(s) an opening or inlet to the second compartment extends across the width of the first heat exchanger, such that washed off fluff, i.e. dirty liquid, is efficiently collected in the second compartment. For example the second compartment extends below a front portion of the first heat exchanger at least 1/10, 1/8, 1/5, 1/4 of the first heat exchanger length in direction of the process air flow to ensure that all dirty liquid is collected during and after a cleaning phase of the first heat exchanger.

According to an embodiment the second compartment is fluidly connected to a front portion of the first heat exchanger by means of a drain conduit, such that liquid is conveyed from the front of the first heat exchanger to a rear portion of the base unit, wherein at least a portion of the conduit is arranged within or is passing through the first compartment. Alternatively at least a portion of the conduit is arranged and/or passing at a side of the first compartment. According to a further alternative at least a portion of the conduit is arranged below the first compartment, i.e. a drain conduit in form of a 'tunnel' is provided to convey dirty liquid collected at a front portion of the first heat exchanger to a rear portion of the treatment apparatus, whereby the first and second compartment can be arranged in a basement of the treatment apparatus in a space-saving manner.

The first and second compartment may be fluidly connected, e.g. by an overflow element between first and second compartment. For example an overflow element or wall is adapted such that clean liquid from the first compartment only overflows to the second compartment, but not the opposite way. Thus it is provided that excess clean water may be discharged from the first compartment, while preventing that the clean liquid in the first compartment is contaminated by dirty liquid from the second compartment.

Preferably the cleaning means comprises a two-way valve controlled by a control unit of the treatment apparatus to selectively supply liquid to the first heat exchanger from the first compartment or alternatively from an intermediate tank, For example clean liquid is supplied to the first heat exchanger from the intermediate tank when not enough liquid for a cleaning phase is collected in the first compartment, e.g. during the beginning of a drying operation of the treatment apparatus. For example clean liquid in the intermediate tank may be left over from a previous drying operation, such that no external liquid supply is necessary. Alternatively or additionally the intermediate tank may be filled with water/liquid by a user. For example for additionally cleaning the heat exchanger between drying operations of the treatment apparatus. Thus it is possible to clean the first heat exchanger without having to execute a drying operation or having to disassemble the treatment apparatus to dismount the heat exchanger for cleaning.

According to an embodiment the cleaning means comprises a valve controlled by a control unit of the treatment apparatus to supply liquid to the first heat exchanger from a liquid or tap water supply, e.g. when a drying operation starts or when a liquid level in the first compartment drops below a minimum level an external liquid supply is provided for cleaning the first heat exchanger.

Preferably the treatment apparatus comprises a liquid level detector for detecting a liquid level in the first compartment, wherein the control unit is adapted to supply liquid to the first compartment when a liquid level of the compartment drops below a predetermined minimum level. The liquid may be supplied to the first compartment from an intermediate tank or alternatively from a liquid or tap water supply. Thus it is at all times ensured that the amount of clean liquid in the first compartment is sufficient for cleaning the first heat exchanger.

The cleaning means may comprise a two-way valve controlled by a control unit of the treatment apparatus to supply liquid selectively from the first compartment to an extractable container or to the outside of the treatment apparatus. Thus excess clean liquid may be removed from the treatment apparatus. Alternatively, a more economical embodiment may comprise of a manual operation to disconnect the liquid supply directed towards the extractable container and direct all the "dirty" water collected after the cleaning operation to the outside of the apparatus.

Reference is made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying figures, which show:

Fig. 1

a schematic view of components of a laundry treatment apparatus according to a first embodiment,

Fig. 2

a schematic view of components of a laundry treatment apparatus according to a second embodiment,

Fig. 3

a schematic side view of a detail of Figs. 1 and 2,

Fig. 4a-b

perspective rear/side views of a basement for a laundry treatment apparatus,

Figs. 5a-b

perspective front/side views of the basement of Figs. 4a-b,

Fig. 6

a perspective sectional side view of the basement of Figs. 4a-b,

Fig. 6a

a detail of Fig. 6, and

Figs. 7 to 9

perspective sectional front/side views of the base unit of Figs. 4a-b in succeeding assembly steps.

Figs. 1 to 3 show schematic views of selected elements or components of a laundry treatment apparatus having a heat pump system, which is in the following embodiments a heat pump tumble dryer. The schematically depicted elements are incorporated amongst others in a heat pump tumble dryer and are selected to illustrate the general concept of the invention.

A heat pump tumble dryer comprises a laundry compartment or drum arranged in a housing of the apparatus for receiving laundry to be dried therein. A first heat exchanger 2 (evaporator) for cooling and dehumidifying process air and a second heat exchanger 4 (condenser - see Fig. 3) for heating process air is arranged in a process air loop of the apparatus, in particular in a battery channel 32 (Fig. 4a) arranged in a basement 6 (Fig. 4a) of the treatment apparatus. During a drying operation of the apparatus and controlled by a control unit of the treatment apparatus (moist) process air is conveyed through the closed process air loop from the laundry drum through the first and second heat exchanger 2, 4, i.e. through the battery channel 32, and subsequently the heated and dehumidified process air is fed back into the laundry drum for drying laundry therein.

With reference to Fig. 1, when laundry is dried, fluff is generated in the drum which is carried by the process air to the first heat exchanger 2, where it accumulates at a front surface 10 or front portion of the heat exchanger 2 which is hit by process air first. The gradually accumulating fluff deteriorates the heat exchanger performance of the heat exchanger 2. To prevent this the treatment apparatus comprises a cleaning means for cleaning a front portion or front surface 10 of the first heat exchanger 2. The cleaning means comprises a spray head 38, a feed pipe 46 and a first pump 40 to convey liquid to the heat exchanger surface 10, i.e. to wash off the accumulated fluff. The spray head 38 is fed with condensate collected from the first heat exchanger 2 in a first compartment 16 arranged in the basement 6 below the heat exchangers 2, 4. For example the spray head 38 is adapted to spray liquid to an upper portion of the first heat exchanger 2 by means of a first pump 40 from where the cleaning liquid flows down the heat exchanger surface 10 by means of gravity and washes off fluff thereby.

The washed off fluff, i.e. the dirty or contaminated liquid, is collected in a second compartment 18 arranged in the basement 6 below the first heat exchanger 2. A portion of the second compartment 18 may also have an extension below the second heat exchanger 4 - preferably with a liquid scaling partition wall between the second heat exchanger 4 and the second compartment.

The collected dirty liquid may be drained to the outside of the treatment apparatus by means of a second pump 42 or drain pump and a drain pipe 48 (a respective drain pipe 48' is shown in Fig. 2 for the second embodiment). As shown in Fig. 1 the treatment apparatus may comprise a removable tank 36 for collecting excess liquid from the second compartment 18, which can be emptied by a user as required, i.e, when a maximum level is reached. For convenience the removable tank 36 may be located or arranged at an upper portion of the treatment apparatus which is easily accessible for a user.

A valve 44 is provided to selectively feed liquid to the removable tank 36 or to the outside of the treatment apparatus, e.g. first the removable tank 36 is filled up to a predetermined maximum capacity and any further liquid is discharged to the outside of the apparatus. For example a liquid level detector connected to the control unit of the treatment apparatus is adapted to detect the liquid level in the second compartment 18, wherein the control unit is adapted to operate the second pump 42 and to open the valve 44 selectively to the removable tank 36 or to the outside when a maximum liquid level is reached. Alternatively valve 44 is omitted and a pipe branch is provided at the position of the valve 44. By disconnecting the line of drain pipe 48 towards the removable tank 36, the liquid is then drained to the outside of the cabinet (not shown) of the apparatus through the outgoing line of the drain pipe 48.

As shown in Fig. 2, alternatively or additionally a removable condensate container 37 or tank is provided which is connected to the first compartment 16 and to the spray head 3 8 by means of a two-way valve 44'. Thus clean liquid, i.e. condensate, from the first container 16 may be collected and removed from the treatment apparatus, e.g. to be used for ironing. Unless otherwise mentioned, the statements relating to Fig. 1 also apply for the second embodiment of Fig. 2.

In order to convey the collected cleaning liquid from the tank 37 to the first heat exchanger 2 the two-way valve 44' may be replaced by a three-way valve. Thus clean liquid (condensate) may be conveyed from the first compartment 16 to the condensate tank 37, may be supplied from the first compartment 16 to the spray head 38 or may be supplied from the tank 37 to the spray head 38. For example the condensate container 37 is arranged above or higher than the spray head 38, such that liquid from the condensate container 37 may be conveyed to the spray head 38 and through feed pipe 46' by gravity, i.e. controlled by the control unit the three-way valve is opened to feed liquid to the spray head 38, for example when the amount of liquid in the first compartment 16 has not reached a minimum level sufficient for cleaning the first heat exchanger 2.

Fig. 3 schematically shows the flow of liquid from the first compartment 16 to the first heat exchanger 2 and into the second compartment 18 with arrows which is the same for all above described embodiments. After conveying clean liquid from the first compartment 16 by means of the first pump 40 to the front surface 10 or portion of the first heat exchanger 2, the liquid flows down the heat exchanger 2 surface and washes off accumulated fluff. The dirty liquid comprising the washed off fluff flows downwards into the second compartment 18. A front portion or section of the first heat exchanger 2, which is cleaned with liquid from the first compartment 16, is indicated by 'B' and is arranged above the second compartment 18, i.e. above an inlet 28 to the second compartment 18. Thus it is ensured that all the dirty cleaning liquid flows into the second compartment 18 and no or essentially no dirty liquid flows into the first compartment 16. The rear and middle portion of the first heat exchanger 2, where condensate is generated during a drying operation, is indicated by 'A' and is arranged above the first compartment 16, such that the generated condensate, i.e. clean liquid, is collected in the first compartment 16.

Figs. 4a-b show perspective rear views of a portion of a basement 6 of the treatment apparatus. Unless otherwise mentioned, the basement 6 of Figs. 4a-b may comprise the schematically depicted components of the embodiments as described above. The reference numerals for elements described above are used for the same elements in the following embodiment.

The basement 6 is formed by an upper shell and a lower shell 8, wherein the upper shell is omitted to allow a better view onto the internal structure and components arranged in the basement 6. During a drying process a process air channel guides the process air from the outlet of the laundry chamber (not shown and preferably a drum) to the inlet of the laundry compartment preferably such that a closed process air loop is formed. A portion of the process air channel is formed between inner walls of the upper shell and lower shell 8. In Fig. 4a those portions are indicated which form part of the channel, namely a front section channel 30a which guides the air downward from the treatment chamber into a battery channel, which houses the heat exchangers 2,4. The process air leaves the battery channel 32 through the rear channel section 30b where the process air blower (only housing part shown) is arranged. The first heat exchanger 2 (evaporator) cools and dehumidifies the process air and the second heat exchanger 4 heats the process air. Both are arranged in the battery channel 32 where only the first heat exchanger 2 is shown in Fig. 4a. The second heat exchanger 4, which is arranged downstream the first heat exchanger 2 with respect to process air flow is omitted to allow a better view of the structure. The first heat exchanger 2 is held in its operating position by retaining elements 14a-b protruding from inner walls of the lower shell 8,

A cover panel 12 or a cover plate forms a bottom or lower boundary of the battery channel 32. As shown in Fig. 4b - where the cover panel 12 is removed for illustrative purposes - the first and second compartments 16,18 are arranged below the cover panel 12, i.e. below the heat exchangers 2, 4. The front portion of the cover panel 12, which is arranged below the first heat exchanger 2 comprises a plurality of slits 26a-g (Fig. 5a) below the middle and rear portion of the first heat exchanger 2, such that condensate generated at the first heat exchanger 2 flows through the slits 26a-g into the first compartment 16 below the first heat exchanger 2.

A front portion of the first heat exchanger 2, which is cleaned by a cleaning means or spray head 38 as described above, is arranged above the opening or inlet 28 (Fig. 5a) to the second compartment 18. In other words the second compartment 18 extends below a front portion of the first heat exchanger 2. The inlet 28 has the same or essentially the same width as the first heat exchanger 2 to assure that all the dirty liquid flowing down the heat exchanger front surface 10 is collected. Thus when the front surface 10 of the first heat exchanger 2 is washed with clean liquid, the dirty liquid flows through the inlet 28 into the second compartment 18 from where it may be pumped to an outside of the apparatus or to an extractable container 36 as described above.

Figs. 5a-b show perspective front/side views of the lower shell 8 of Figs. 4a-b without the first heat exchanger 2. As shown in Fig. 5b - where the cover panel 12 is removed - the first compartment 16 is arranged below a middle and rear portion of the first heat exchanger 2 and below the second heat exchanger 4 and extends to the rear of the lower shell 8 or basement 6 to a first sump 20 (Fig. 4a) where the first pump 40 is arranged to pump liquid to the spray head 38 for cleaning the first heat exchanger 2 as described above. The compartments 16, 18 are divided from each other by a dividing wall 24. The second compartment 18 extends to a front portion of the lower shell 8, i.e. below a front portion of the first heat exchanger 2. to the area which is washed by a cleaning means as described above. The second compartment 18 extends from the front of the lower shell 8 along a side of the lower shell 8 to the rear of the basement 6. The second compartment 18 is connected to a second sump 22 (Fig, 4a) at the rear of the basement 6 or shell 8 by a drain conduit 34 or tunnel arranged at a rear portion of the lower shell 8. The second pump 42 is arranged in the second sump 22 to pump dirty liquid to the outside of the apparatus or to a removable tank 36 as described above.

Fig. 6 shows a perspective sectional side/front view of the lower shell 8 of Figs. 4a-b and Fig. 6a shows a detail of the view of Fig. 6. Fig, 6a depicts the front and side portion of the lower shell 8 with the inlet 28 to the second compartment 18, wherein the flow of dirty water from the first heat exchanger 2 to the inlet 28 and into the second compartment is illustrated with arrows B.

Figs. 6 to 9 show succeeding assembly steps of the basement 6 of Figs. 4a-b in perspective sectional side views. First the cover panel 12 is placed in the lower shell 8 until it reaches its end position as shown in Fig. 7, In this position the lower side of panel 12 rests on the upper face of dividing wall 24. In Fig. 8 the cover panel 12 is depicted semi-transparent to depict the position of the compartments 16, 18 with respect to the slits 26a-g or openings in the cover panel 12. To allow an even discharge of condensate through the cover panel, i.e. to prevent any congestion, the slits 26a-g are evenly distributed over a base area of the first heat exchanger 2. It is noted that due to the even distribution of the slits 26a-g not all of the slits 26a-g are arranged above the first compartment 16. i.e. a very small amount of condensate flows into the second compartment 18 through slit 26a. In Fig. 9 the first heat exchanger 2 is inserted in its operating position in the lower shell 8 between the protruding retaining elements 14a-b. It is shown that the position of the first heat exchanger 2 is such that liquid sprayed or conveyed to its front surface 10 is reliably collected via the inlet 28 in the second compartment 18.

2

first heat exchanger (evaporator)

4

second heat exchanger (condenser)

6

basement

8

lower shell

10

heat exchanger front surface

12

cover panel

14a-b

retaining element

16

first compartment (collection tank)

18

second compartment (collection tank)

20

first sump

22

second sump

24

dividing wall

26a-g

slit opening

28

second compartment inlet

30a, 30b

front and rear section of process air channel

32

battery channel

34

drain conduit / tunnel

36

removable water tank

37

condensate tank

38

spray head

40

first pump

42

second pump

44, 44'

valve

46, 46'

feed pipe

48, 48'

drain pipe

A

clean liquid/condensate flow

B

dirt liquid flow (with fluff)