CN209857488U - Drainage device of refrigeration equipment and refrigeration equipment - Google Patents

Abstract

The utility model discloses a refrigeration plant's drainage device and refrigeration plant, refrigeration plant include the evaporation cavity, and it is enclosed by bottom plate and housing, are equipped with evaporimeter and air intake in the evaporation cavity, and the below of evaporimeter is equipped with the water collector, and air intake department is equipped with the air inlet circle, and air intake and water collector are all located on the bottom plate. The drainage device comprises a flow guide body assembly, wherein the flow guide body assembly is arranged on the bottom plate and is positioned in the evaporation chamber, one side wall of the flow guide body assembly is abutted to the outer peripheral wall of the air inlet air ring, one side wall of the flow guide body assembly is abutted to the water receiving disc, and one side wall of the flow guide assembly is abutted to the inner wall of the housing. Condensed dew on the housing drops onto the flow guide body assembly, and the flow guide body assembly guides the condensed dew dropping on the flow guide body assembly into the water receiving tray, so that water accumulated on the bottom plate is avoided, the water accumulated on the bottom plate is prevented from overflowing from the air inlet, and the water leakage at the top of the refrigerator is avoided.

Description

Drainage device of refrigeration equipment and refrigeration equipment

Technical Field

The utility model relates to a refrigeration plant technical field especially relates to a refrigeration plant's drainage device and refrigeration plant.

Background

Present kitchen refrigerator, some locate kitchen refrigerator's top with the evaporimeter, during the installation, the top of refrigerator is equipped with the installation cavity that is used for installing the evaporimeter, is equipped with the bottom plate in the installation cavity, and bottom plate and refrigerator's inner bag fixed connection are equipped with evaporimeter and air intake on the bottom plate, and the lower part of evaporimeter is equipped with the water collector, and the water collector is used for flourishing evaporimeter defrosting water when changing the frost, and air intake department is equipped with air intake fan. The periphery of the evaporator and the air inlet fan is provided with a housing which is fixedly connected with the bottom plate, and the space enclosed between the housing and the bottom plate is an evaporation chamber. The air in the storage compartment flows into the evaporation chamber from the air inlet under the suction action of the air inlet fan to exchange heat with the evaporator, becomes cold air and then flows out from the air outlet (not shown). In the process of refrigeration operation of the evaporator, the temperature in the evaporation chamber is low, the temperature of air outside the housing is higher than that of air in the evaporation chamber, so that low-temperature air in the evaporation chamber can be condensed into water drops after contacting with the housing, and condensed water flows down to the bottom plate along the housing to cause water accumulation on the bottom plate. The existing kitchen refrigerator generally has no structure for draining accumulated water on the bottom plate, the accumulated water on the bottom plate cannot be drained at any time, and the accumulated water can influence the refrigeration effect of the evaporator; meanwhile, when accumulated water is accumulated continuously until the height of the accumulated water exceeds the height of the air ring of the air inlet, the accumulated water on the bottom plate can overflow from the air inlet, so that water leakage at the top of the kitchen refrigerator is caused, and the use effect of the refrigerator is seriously influenced.

The above information disclosed in this background section is only for enhancement of understanding of the background of the application and therefore it may comprise prior art that does not constitute known to a person of ordinary skill in the art.

Disclosure of Invention

The utility model aims to solve the technical problem, a refrigeration plant's drainage device and refrigeration plant are provided, it can avoid bottom plate ponding, avoid bottom plate ponding from the air intake excessive, avoid the refrigerator top to leak with the condensation water conservancy diversion on the housing to the water collector in.

In order to realize the purpose of the utility model, the utility model adopts the following technical scheme to realize:

the utility model provides a refrigeration plant's drainage device, refrigeration plant includes: the evaporation chamber is enclosed by a bottom plate and a housing, an evaporator and an air inlet are arranged in the evaporation chamber, a water pan is arranged below the evaporator, an air inlet ring is arranged at the air inlet, and the air inlet and the water pan are both arranged on the bottom plate; the drainage device includes: the water guide body assembly is arranged on the bottom plate and positioned in the evaporation chamber, one side wall of the water guide body assembly is abutted with the peripheral wall of the air inlet ring, one side wall of the water guide body assembly is abutted with the water receiving disc, and one side wall of the water guide body assembly is abutted with the inner wall of the housing; the condensed water condensed on the encloser flows to the flow guide body component along the inner wall of the encloser, and the flow guide body component guides the condensed water dropping on the flow guide body component into the water receiving tray.

Furthermore, the flow guide body assembly comprises two flow guide bodies, and the two flow guide bodies are symmetrically arranged on two sides of the air inlet air ring; the flow guide body comprises a first side wall, a second side wall, a third side wall and a flow guide surface, the flow guide surface is respectively connected and intersected with the first side wall, the second side wall and the third side wall, the first side wall is abutted against the outer peripheral wall of the air inlet air ring, the second side wall is abutted against the side wall of the water receiving disc, the third side wall is abutted against the inner wall of the housing, the connection intersection position of the first side wall and the flow guide surface is higher than the end face of the air inlet air ring, and the connection intersection position of the second side wall and the flow guide surface is higher than the side wall of the water receiving disc; the condensed water dropping on the flow guide body flows into the water receiving tray through the flow guide surface.

Furthermore, the flow guide surface is of an inclined surface structure and gradually decreases from the direction away from the lateral side of the water receiving tray and close to the lateral side of the water receiving tray, and gradually decreases from the direction close to the lateral side of the air inlet ring and away from the lateral side of the air inlet ring.

Furthermore, the inclination angle of the flow guide surface from the side far away from the water pan to the side close to the water pan is 8-12 degrees, and the inclination angle of the flow guide surface from the side close to the air inlet ring to the side far away from the air inlet ring is 8-12 degrees.

Furthermore, one side of the flow guide surface, which is close to the air inlet air ring, is provided with a water retaining rib.

Furthermore, one side of the flow guide surface, which is far away from the air inlet air ring, is internally accommodated on the side wall of the water receiving tray, which is abutted against the flow guide surface.

Further, an air inlet fan is arranged at the air inlet and is connected with the bottom plate through a support; and a support avoiding part for avoiding the support is arranged on the flow guide body.

Furthermore, a temperature sensor is arranged at a position, close to the air inlet air ring, on the bottom plate, and a sensor avoiding part for avoiding the temperature sensor is arranged on the flow guide body.

Furthermore, the material of the flow guide body component is heat-insulating foam.

The utility model also provides a refrigeration plant, including the inner bag, the upper portion of inner bag is equipped with evaporation cavity, evaporation cavity is enclosed by bottom plate and housing, be equipped with evaporimeter and air intake in the evaporation cavity, the below of evaporimeter is equipped with the water collector, air intake department is equipped with the air inlet circle, the air intake with the water collector is all located on the bottom plate, be equipped with as above in the evaporation cavity drainage device.

Compared with the prior art, the utility model discloses an advantage is with positive effect:

the utility model provides a refrigeration plant's drainage device and refrigeration plant, refrigeration plant include the evaporation cavity, and it is enclosed by bottom plate and housing, are equipped with evaporimeter and air intake in the evaporation cavity, and the below of evaporimeter is equipped with the water collector, and air intake department is equipped with the air inlet circle, and air intake and water collector are all located on the bottom plate. The drainage device comprises a flow guide body assembly, wherein the flow guide body assembly is arranged on the bottom plate and is positioned in the evaporation chamber, one side wall of the flow guide body assembly is abutted to the peripheral wall of the air inlet ring, one side wall of the flow guide body assembly is abutted to the water receiving disc, and one side wall of the flow guide assembly is abutted to the inner wall of the housing. Condensed dew on the housing drops onto the flow guide body assembly, and the flow guide body assembly guides the condensed dew dropping on the flow guide body assembly into the water receiving tray, so that water accumulated on the bottom plate is avoided, the water accumulated on the bottom plate is prevented from overflowing from the air inlet, and the water leakage at the top of the refrigerator is avoided.

Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic overall structure diagram of a refrigeration device according to an embodiment of the present invention;

fig. 2 is a first schematic structural diagram of an evaporation chamber according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of an evaporation chamber according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram three of an evaporation chamber according to an embodiment of the present invention;

fig. 5 is a first schematic structural view of a baffle according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a baffle according to an embodiment of the present invention;

fig. 7 is a third schematic structural view of a baffle according to an embodiment of the present invention;

fig. 8 is a fourth schematic structural view of a baffle according to an embodiment of the present invention.

100-a guide body, 110-a first side wall, 120-a second side wall, 130-a third side wall, 140-a guide surface, 141-a water retaining rib, 150-a sensor avoiding part, 160-a support avoiding part, 161-a first support avoiding part, 162-a second support avoiding part, 170-a connecting hole, 180-a bottom surface, 200-refrigeration equipment, 210-a box body, 220-an evaporation chamber, 230-an evaporator, 240-a bottom plate, 241-a connecting column, 242-an upright column, 250-a water pan, 260-a housing, 270-an air inlet, 271-an air inlet fan, 272-an air inlet ring, 2721-an inner end surface, 2722-an inner peripheral wall, 280-a support, a 281-support first part, a 282-support second part and 283-a support third part;

10-space a, 20-space B.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The utility model discloses a drainage device of refrigeration plant, for the convenience of explanation and understanding the utility model discloses drainage device's structure and effect before carrying out the detailed description to drainage device's structure, this paper will be brief in the refrigeration plant with the structure that this drainage device's setting is relevant.

Referring to fig. 1 to 4, in fig. 1, the cover 260 is omitted to clearly see the internal structure of the evaporation chamber 220; the housing 260, evaporator 230 and current carrier assembly are omitted from fig. 3 to provide a clear view of the structure within the evaporation chamber 220 prior to installation of the current carrier assembly; the casing 260 and the evaporator 230 are omitted from fig. 4. The refrigeration equipment, such as a vertical kitchen refrigerator, includes a box body 210, an inner container (not labeled) is arranged in the box body 210, an evaporation chamber 220 is arranged on the upper portion of the inner container, the evaporation chamber 220 is enclosed by a bottom plate 240 and a cover 260, the cover 260 is fixedly connected with the bottom plate 240, and the bottom plate 240 is fixedly connected with the inner container. An evaporator 230 and an air inlet 270 are arranged in the evaporation chamber 220, a water pan 250 is arranged below the evaporator 230, an air inlet ring 272 and an air inlet fan 271 are arranged at the air inlet 270, and the water pan 250 and the air inlet 270 are both arranged on the bottom plate 240. Air in the storage compartment of the refrigeration device flows into the evaporation chamber 220 from the air inlet 270 under the suction action of the air inlet fan 271 to exchange heat with the evaporator 230, and then flows out from the air outlet (not shown) after being changed into cold air. After the evaporator 230 operates for a period of time, it needs to be defrosted, and defrosted water directly drops into the water pan 250 to be discharged. In the process of the cooling operation of the evaporator 230, the temperature in the evaporation chamber 220 is low, and the temperature of the air outside the casing 260 is higher than the temperature of the air in the evaporation chamber 220, so that the low-temperature air in the evaporation chamber 220 contacts the casing 260 and is condensed into water drops, and the condensed water flows down to the bottom plate 240 along the casing 260. The utility model discloses drainage device's effect just lies in discharging in will flowing down condensation water conservancy diversion to water collector 250 along housing 260, avoids bottom plate 240 ponding from air intake 270 excessive, avoid the refrigerator top to leak.

The drainage device includes a flow guiding body assembly, referring to fig. 4 to 8, the flow guiding body assembly is disposed on the bottom plate 240 and located in the evaporation chamber 220, one of the side walls of the flow guiding body assembly abuts against the peripheral wall of the air inlet duct 272, one of the side walls of the flow guiding body assembly abuts against the water receiving tray 250, and one of the side walls of the flow guiding body assembly abuts against the inner wall of the housing 260. The condensed water condensed on the casing 260 flows onto the flow guide member along the inner wall of the casing 260, and the flow guide member guides the condensed water dropping thereon into the drain pan 250.

Specifically, the baffle assembly includes two baffles 100, the two baffles 100 are symmetrically disposed on two sides of the air inlet duct 272, fig. 5 and 6 are schematic structural diagrams of the baffles 100 disposed on one side of the air inlet duct 272, and fig. 7 and 8 are schematic structural diagrams of the baffles 100 disposed on the other side of the air inlet duct 272. The two flow conductors 100 differ only in that one of the flow conductors 100 is provided with a sensor escape 150 (see fig. 5 and 6) for avoiding a sensor, and the details will be described in detail below. Of course, if the temperature sensors are disposed on both sides of the air inlet duct 272, the sensor avoiding portion 150 is required to be disposed on both of the flow conductors 100. The installation position of the sensor escape portion 150 on the baffle 100 depends on the specific installation position of the temperature sensor.

As can be seen from fig. 3, there is a certain space between the water pan 250 and the air inlet duct 272, the space between the water pan 250 and one side of the air inlet duct 272 is denoted as a space a 10, and the space between the water pan 250 and the other side of the air inlet duct 272 is denoted as a space B20. An end surface of the air inlet duct 272 on the side of the evaporation chamber 220 is defined as an inner end surface 2721 thereof, the inner end surface 2721 of the air inlet duct 272 protrudes from the bottom plate 240, that is, a certain distance is provided between the inner end surface 2721 of the air inlet duct and the bottom plate 240, and a portion between the inner end surface 2721 of the air inlet duct and the bottom plate 240 is defined as an inner peripheral wall 2722 of the air inlet duct. The air inlet fan 271 is fixedly connected with the bottom plate 240 through the support 280, the support 280 comprises a support first part 281, a support second part 282 and a support third part 283, the support first part 281 and the support third part 283 are horizontally arranged, the support second part 282 is vertically arranged between the support first part 281 and the support third part 283, the support second part 282 is tightly abutted with the outer side of the inner peripheral wall 2722 of the air inlet air ring, and the support third part 283 is fixedly connected with the bottom plate 240 through a screw. Before the drainage device is not installed, condensed water condensed on the housing 260 can drip onto the bottom plate 240 along the housing 260, and is continuously accumulated on the bottom plate 240, and when the condensed water in the bottom plate 240 is accumulated to a certain amount, the condensed water can overflow the air inlet air ring 272 and flow out from the air inlet 270, so that water leakage at the top of the refrigerator is caused. Meanwhile, the insufficient availability of the condensed water to be discharged in time also reduces the cooling efficiency of the evaporator 230.

Referring to fig. 4, in the present embodiment, the flow guiding body assembly is installed in a space between the water receiving tray 250 and the air inlet ring 272, that is, one of the flow guiding bodies 100 is disposed in the space a 10, and the other flow guiding body 100 is disposed in the space B20, so as to guide the condensed water flowing down along the inner wall of the casing 260 to the water receiving tray 250, and further discharge the condensed water in time. The outer contour of current carrier 100 is determined by the specific shape of space a 10 and space B20.

In this embodiment, referring to fig. 5 to 8, the specific structural shape of the baffle 100 is that the baffle 100 includes a first sidewall 110, a second sidewall 120, a third sidewall 130, and a baffle surface 140, the baffle surface 140 is respectively connected to the first sidewall 110, the second sidewall 120, and the third sidewall 130, the first sidewall 110 is in adaptive abutment with an outer side of an inner peripheral wall 2722 of the air inlet ring 272, the second sidewall 120 is in adaptive abutment with a sidewall of the water receiving tray 250, and the third sidewall 130 is in adaptive abutment with an inner wall of the housing 260. The surface of flow guiding body 100 opposite to flow guiding surface 140 is referred to as bottom surface 180, bottom surface 180 is a planar structure, and bottom surface 180 abuts against bottom plate 240. In order to realize the flow guiding function, the flow guiding surface 140 is configured as an inclined surface structure, which gradually decreases from the direction away from the water pan 250 side to the side close to the water pan 250 side, and gradually decreases from the direction close to the air inlet ring 272 side to the side far from the air inlet ring 272 side.

One side of the housing 260 abutting against the third side wall 130 is an arc-shaped structure, and correspondingly, the third side wall 130 is also provided with the arc-shaped structure, so that the third side wall 130 can be in adaptive abutting against with the inner wall of the housing 260 well, and condensed water flowing down along the housing 260 can flow onto the flow guide surface 140.

In order to prevent condensed water dropping on the flow guide surface 140 from flowing out of the air inlet 270, a meeting intersection position (marked as S) of the first side wall 110 and the flow guide surface 140 is set to be higher than an inner end surface 2722 of the air inlet air ring 272. In order to prevent the condensed water dropping on the diversion surface 140 from smoothly flowing into the drain pan 250, the junction (marked as P) of the second side wall 120 and the diversion surface 140 is higher than the side wall of the drain pan 250. The condensed water condensed on the casing 260 flows down to the flow guide surface 140 along the inner wall of the casing 260, and flows into the water receiving tray 250 under the flow guide effect of the flow guide surface.

The inclination angle of the flow guide surface 140 from the side far away from the water-receiving tray 250 to the side close to the water-receiving tray 250 is 8-12 degrees, and preferably 10 degrees; the angle of inclination of the deflector surface 140 from the side close to the inlet funnel 272 to the side away from the inlet funnel 272 is 8-12 °, preferably 10 °.

In order to prevent the condensed water dropping on the flow guiding surface 140 near the air inlet 270 from being exposed from the air inlet 270 due to splashing, a water blocking rib 141 is disposed on one side of the flow guiding surface 140 near the air inlet ring 272, and the water blocking rib 141 extends and is distributed along the meeting intersection position of the flow guiding surface 140 and the first side wall 110.

When the two diversion bodies 100 are installed on the bottom plate 240, one side of the diversion surface 140, which is far away from the air inlet air ring 272, is inwardly retracted to the side wall of the water pan 250, which is abutted to the diversion surface, so that condensed water on the diversion surface 140 can flow into the water pan 250 and cannot flow to the outside of the water pan 250.

Be equipped with on the baffle 100 and dodge the portion 160 for the support that support 280 abduced, it is specific, support dodge portion 160 includes first support dodge portion 161 and second support dodge portion 162, and first support dodge portion 161 is used for abdicating for support two parts 282, and second support dodge portion 162 is used for abdicating for support three parts 283.

A temperature sensor is typically located within the evaporation chamber 220 and is generally located near the air intake 270. In actual installation, a plurality of hollow columns 242 are pre-installed on the base plate 240, and the temperature sensor is fixed in the column 242. The posts 242 are typically of a plastic construction and are easily damaged or broken. The sensor avoiding portion 150 for avoiding the upright column 242 is arranged on the first side wall 110, and referring to fig. 5 and 6, the sensor avoiding portion 150 plays a role in protecting the upright column 242, and encloses and blocks the upright column 242 between the first side wall 110 and the inner peripheral wall of the air inlet wind ring 272, so that the upright column 242 is effectively prevented from being damaged or broken.

The two flow conductors 100 are made of high-density heat-insulating foam, so that the flow conductors 100 have the functions of heat insulation and heat preservation while realizing the flow guiding function, and the loss of cold in the evaporation chamber 220 is reduced.

The flow guide body 100 is fixedly connected with the bottom plate 240 in an interference clamping mode, specifically, a connecting column 241 is arranged on the bottom plate 240, a connecting hole 170 which is matched and clamped with the connecting column is formed in the flow guide body 100, and the connecting column 241 is inserted into the connecting hole 170 so as to fixedly install the flow guide body 100 on the bottom plate 240.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims (10)

1. A drain for a refrigeration appliance, the refrigeration appliance comprising:

the evaporation chamber is enclosed by a bottom plate and a housing, an evaporator and an air inlet are arranged in the evaporation chamber, a water pan is arranged below the evaporator, an air inlet ring is arranged at the air inlet, and the air inlet and the water pan are both arranged on the bottom plate;

characterized in that the drainage device comprises:

the water guide body assembly is arranged on the bottom plate and positioned in the evaporation chamber, one side wall of the water guide body assembly is abutted with the peripheral wall of the air inlet ring, one side wall of the water guide body assembly is abutted with the water receiving disc, and one side wall of the water guide body assembly is abutted with the inner wall of the housing;

the condensed water condensed on the encloser flows to the flow guide body component along the inner wall of the encloser, and the flow guide body component guides the condensed water dropping on the flow guide body component into the water receiving tray.

2. The drain device of a refrigeration apparatus according to claim 1,

the flow guide body assembly comprises two flow guide bodies, and the two flow guide bodies are symmetrically arranged on two sides of the air inlet air ring;

the flow guide body comprises a first side wall, a second side wall, a third side wall and a flow guide surface, the flow guide surface is respectively connected and intersected with the first side wall, the second side wall and the third side wall, the first side wall is abutted against the outer peripheral wall of the air inlet air ring, the second side wall is abutted against the side wall of the water receiving disc, the third side wall is abutted against the inner wall of the housing, the connection intersection position of the first side wall and the flow guide surface is higher than the end face of the air inlet air ring, and the connection intersection position of the second side wall and the flow guide surface is higher than the side wall of the water receiving disc;

the condensed water dropping on the flow guide body flows into the water receiving tray through the flow guide surface.

3. The drain device of a refrigeration apparatus according to claim 2,

the flow guide surface is of an inclined surface structure and gradually decreases from the direction far away from the lateral direction of the water receiving tray and close to the lateral side of the water receiving tray, and gradually decreases from the direction near the lateral direction of the air inlet air ring and far away from the lateral side of the air inlet air ring.

4. The drain device of a refrigeration apparatus according to claim 3,

the inclination angle of the flow guide surface from the side far away from the water receiving tray to the side close to the water receiving tray is 8-12 degrees, and the inclination angle of the flow guide surface from the side close to the air inlet ring to the side far away from the air inlet ring is 8-12 degrees.

5. The drain device of a refrigeration apparatus according to claim 3,

one side of the flow guide surface, which is close to the air inlet air ring, is provided with a water retaining rib.

6. The drain device of a refrigeration apparatus according to claim 5,

one side of the diversion surface, which is far away from the air inlet air ring, is internally folded on the side wall of the water receiving tray, which is abutted against the diversion surface.

7. A drain device of a refrigerating apparatus according to any one of claims 2 to 6,

an air inlet fan is arranged at the air inlet and is connected with the bottom plate through a support;

and a support avoiding part for avoiding the support is arranged on the flow guide body.

8. A drain device of a refrigerating apparatus according to any one of claims 2 to 6,

the bottom plate is provided with a temperature sensor at a position close to the air inlet air ring, and the flow guide body is provided with a sensor avoiding part for avoiding the temperature sensor.

9. The drain device of a refrigeration apparatus according to claim 1,

the material of baffle subassembly is the heat preservation foam.

10. A refrigeration device comprises an inner container, wherein an evaporation chamber is arranged on the upper portion of the inner container, the evaporation chamber is formed by a bottom plate and a housing in a surrounding mode, an evaporator and an air inlet are arranged in the evaporation chamber, a water receiving disc is arranged below the evaporator, an air inlet ring is arranged at the air inlet, the air inlet and the water receiving disc are both arranged on the bottom plate, and the refrigeration device is characterized in that the evaporation chamber is internally provided with the water drainage device as claimed in any one of claims 1 to 9.