FR2726583A1 - WASHING AND DRYING MACHINE WITH ANTI-FOAM PHASE - Google Patents

Abstract

Washing and drying machine equipped with a washing tub (1), a revolving basket (2) inside said tub and able to contain the articles to be washed, and to rotate at different speeds including the spin speed, a drain duct (5) positioned below said tank, a drying air circulation circuit composed of at least a first suction duct (6) humid air inside the tank, a propeller (7) for circulating said drying air, a heating element (8) for said drying air, and a reintroduction duct (9) of said air in said tank, where, after the washing phase and before the rinsing phase, said hot air circulation propeller (7) is automatically activated for a predetermined time interval (T).

Description

- 1 - 2726583

  WASHING AND DRYING MACHINE WITH ANTI-FOAM PHASE

  The invention relates to a combined machine for washing and drying linen, provided with improved means for the automatic elimination of possible blockages of foam overflowing in the circuit.

drying air circulation.

  Combined machines are known for washing and drying laundry with operation controlled by means of programming the operating cycle, which normally includes, at the end of the washing phase, a

  or several phases of rinsing the laundry.

  It has been observed that under particular operating conditions, for example when the load of detergent substance is excessive, but above all when detergents producing a particularly abundant foam are used, there is an excess of foam in the tank, which , due to the alternating movement of the basket, tends to penetrate all the accessible cavities of the tank. In particular in combined washing and drying machines, excess foam tends to enter the recirculation circuit for hot and humidified air, in the two openings through which said recirculation circuit is connected to the interior of the tank, and in the most severe cases, iL fills said circuit with a quantity of foam which naturally also includes particles of

dirt carried by the Linen.

  This state of affairs causes two types of problems described below: The first problem arises from the fact that the excess foam, by closing all the openings, thus makes the tank an airtight container; In this way, when after the washing phase the successive rinsing phases, and consequently of water loading, take place, the tank is slightly pressurized, since the quantity of water admitted is not compensated by the expulsion of an equivalent volume of air, nor through the water supply duct,

- 2 - 2726583

  since the upper swinging part of the foam that floats on the water rises with the level of this one, and very quickly closes this same water supply duct, allowing the entry of water but preventing L air expulsion. It follows that the pressure switch undergoes a pressure higher than that corresponding to the effective level of the rinsed water admitted, and consequently, it prematurely blocks the inflow of water, inducing the easily imaginable drawbacks. This problem was solved in machines intended only for washing and not for drying, by providing an appropriate exhaust duct of sufficient size, between the top of the tank and the water distribution means located above; however, this solution cannot be applied to a combined machine for washing and drying laundry of the type described, since during drying this duct would behave as an escape for

  The hot air forced into the tank.

  Therefore, in the combined machines for washing and drying clothes, the problem was combated by creating an exhaust duct from the propeller seat directly in said water distribution means, this duct leaving the the air comes out, but due to its length, never completely filling with foam, which could overflow towards the outside. However, this assembly does not avoid the problem of a pressurization of the tank, if the foam fills the duct

drying air intake.

  The second of the two problems generated is linked to the fact that in the successive rinsing and spinning phases, said recirculation circuit not being directly involved from the functional point of view, Said foam remains in said circuit, even after spinning final of

  Laundry, and before The drying phase.

- 3 - 2726583

  Therefore, in the following drying phase, when this recirculation and air heating circuit, whose moisture is condensed, is traversed by said drying air flow, the foam being in this circuit of air circulation is transported again by the circuit in the tank, and reads the laundry irreversibly, since the dirt and the other substances present in the foam can no longer be

Removal of laundry.

  IT would therefore be desirable, and this is the aim of this patent, to be able to have a combined machine for washing and drying laundry which is able to eliminate the problems described by releasing the air circulation circuit. of the foam possibly therein, using the simplest and most common methods, by the use of components already present and by implementing

available technologies.

  The invention will be better understood on reading the

  description which follows, given by way of example only

  limiting, and with reference to the accompanying drawing, in which is shown a schematic drawing of the various components concerned by the invention, in a machine

  combined for washing and drying laundry.

  In the course of the description below, we

  The term "water" will be used interchangeably to mean washing water or rinsing water, but this simplification will not harm the clarity of the presentation, given the context in which these terms are used, as will be immediately obvious to

the man of art.

  Referring to the single figure, which shows a preferred embodiment, is explained a solution according to the invention, as well as its principle of

operation.

  The combined machine described has a washing tank 1, a rotating basket 2 inside said

- 4 - 2726583

  Wash tank, and which is able to contain the items to be washed 3, an electric motor, not illustrated, connected to said basket and able to rotate it at

  variable and selectable speeds beforehand.

  It is also necessary to take into consideration, even if they are not represented, all the other elements known in the state of the art, and which contribute to determining the conditions for correct operation.

of the machine.

  Below said tank, is placed a drain pipe 5, arranged substantially vertically, and which communicates, in its upper part, with the interior thereof, and at its lower end, with a pump

not shown.

  The machine is also provided with a circuit for circulation of the drying air consisting, in the example illustrated, of at least one first duct 6 for sucking wet air from inside the tank, d a propeller 7 for circulating said drying air, a heating element 8 for said drying air and a duct 9 for

  reintroducing said air into said tank.

  In the example described, the propeller chamber 7 is connected, via a conduit 10, to said means 11 for the distribution of water, these means

  can freely offer flow to the outside.

  Said machine is able to execute at least one washing cycle comprising at least one rinsing phase following the washing phase; during said washing phase, the foam generated inside the tank can penetrate deep inside said drying air circulation circuit through the two openings corresponding to the suction duct 6 and to the duct 9 reintroduction of air, by the effect of the alternating movement of the basket, in addition to the excessive production of foam, and it can remain there even after

  rinsing phases, with the drawbacks already mentioned.

- 5 - 2726583

  To avoid this phenomenon, the invention uses, immediately after the end of washing, and for a short period, the propeller 7 for air circulation in the drying duct, so that the air flow is being stabilized inside said circuit, entrains the foam by reintroducing it into the tank, which therefore completely cleans said circuit from all traces of foam. As an experiment, iL has been observed that the passage, for a short period, of the foam inside said circuit does not cause any inconvenience for the components therein, such as the

  condenser, the propeller itself, and the heating element 8.

  Consequently, these operations, by releasing the suction 6 and reintroduction 9 duct, ensure that even in the presence of foam, the tank empties freely, thus making it possible to load a correct quantity of water; moreover, the removal of the foam from said conduits guarantees that the drying phase

  which follows occurs in the total absence of foam.

  It is preferable that the propeller 7 is started up after at least a first emptying of the tank water, in order to limit the presence of foam in the tank, which could be circulated with

  the air sucked and blown, inside said circuit.

  Finally, it was noted that the start-up period of the propeller should be maintained, in domestic machines, for a period of between two and five minutes, in order to guarantee effective cleaning of the circuit, without penalizing the cycle by a

excessive lengthening of its duration.

- 6 - 2726583

Claims (5)

  1. Combined machine for washing and drying laundry, provided with a washing tub (1), a pivoting basket (2) inside said tub and able to contain the articles to be washed (3 ) and able to rotate at different speeds including the spin speed, a drain pipe (5) positioned below said tank, a drying air circulation circuit composed of at least a first humid air suction duct (6) from inside the tank, a propeller (7) for circulating said drying air, a heating element (8) for said drying air, and a duct (9) for reintroducing said air into said tank, said machine being able to carry out at least one washing cycle comprising at least one rinsing phase following the washing phase, characterized in that after said phase of washing, and before said rinsing phase, said propeller (7) for circulating hot air is activated, during a predefined time interval.   2. Machine according to claim 1, characterized in that the activation of said propeller (7) is determined automatically by suitable control means   placed inside said machine.   3. Machine according to claim 1 or 2, characterized in that prior to the activation of said propeller operating phase (7), is drained the tank.   4. Machine according to any one of the claims   above, characterized in that said propeller (7) is   activated after each emptying phase of the tank.   5. Machine according to any one of the claims   above, characterized in that it is provided with a conduit (10) able to put the propeller chamber (7) into communication with means (11) for the distribution of water, said means being able to freely   provide outward flow.