KR20120137476A - Sanitary washing device - Google Patents

Abstract

A sanitary washing apparatus (1) of the present invention comprises a nozzle (7), a water feed passage (9), and a heat exchanger (10). The heat exchanger has a casing (23), a flat plate heater (20), and a flow path space (25). The flow path space is formed such that the width of the gap on the inflow portion side is smaller than the width of the gap on the outflow portion side.

Description

SANITARY WASHING DEVICE

The present invention relates to a sanitary washing apparatus, and more particularly, to a sanitary washing apparatus having a nozzle for spraying hot water.

BACKGROUND ART [0002] Conventionally, a sanitary washing apparatus for blowing hot water from a nozzle is known.

For example, flat-plate heaters are housed vertically in a rectangular parallelepiped-shaped casing having a small thickness dimension. Two flow paths are formed upwardly in a zigzag manner in the horizontal direction along each of the two heat transfer surfaces of the flat plate heater. While the flat plate heater is driven, the washing water flows along the respective flow paths, and the temperature rises to a certain temperature (for example, refer to patent literature).

Japanese Patent Application Laid-Open No. 1998-220876

In the conventional example, there is a possibility that the washing water stagnates in the meandering flow path or the portion where the bubbles become stagnant may occur. In the portion where the washing water stays, the washing water locally boils. In this local boiling portion, a calcium component or the like contained in the washing water adheres to the surface of the flat plate heater, and scale is generated. The heat transfer to the washing water is inhibited by the scale, resulting in locally high temperature of the flat plate heater. In addition, scale generation is promoted, and the passage resistance of the washing water is increased by the deposited scale. Thereby, there is a possibility that the required flow rate of the washing water can not be ensured.

Further, at the portion where the bubbles stagnate, the retention of the washing water and the localized high temperature of the flat plate heater cause the above problems.

Further, when the flat plate heater is locally heated to a high temperature by the scale, a temperature difference occurs in the flat plate heater. Due to the thermal stress caused by the temperature difference, cracks, cracks, and the like are generated in the flat plate heater in a flat plate heater using ceramics as a heating element, and the flat plate heater is broken.

An object of the present invention is to provide a sanitary washing apparatus capable of securing a flow rate of required washing water and preventing a failure.

A sanitary washing apparatus according to one aspect of the present invention includes a nozzle, a water supply path having an upstream end connected to the water supply source and having a downstream end connected to the nozzle, and a heat exchanger provided in the water supply path, The heat exchanger includes an inlet portion, an outlet portion located above the inlet portion, and a plate-like heater formed so as to communicate with the inlet portion at the lower end portion and communicate with the outlet portion at the upper end portion, A flat plate-shaped heater accommodated in the heater accommodating space of the casing so as to extend in the up-and-down direction and including a heat transfer surface facing the main surface of the heater accommodating space; Wherein a width of the gap on the inflow portion side is larger than a width of the gap on the outflow portion side, It is formed to be smaller.

INDUSTRIAL APPLICABILITY The present invention has the above-described structure, and provides a sanitary washing apparatus capable of securing a flow rate of required washing water and preventing failure.

These and other objects, features, and advantages of the present invention will become apparent from the following detailed description of the presently preferred embodiments when read in conjunction with the accompanying drawings.

1 is a perspective view showing a state in which a sanitary washing apparatus according to a second embodiment of the present invention is mounted on a toilet,
Fig. 2 is a plan view showing a front surface of a heat exchanger mounted in the sanitary washing apparatus of Fig. 1, Fig.
Fig. 3 is a plan view showing the right main surface of the heat exchanger of Fig. 2,
Fig. 4 is a cross-sectional view showing the heat exchanger cut along the line AA in Fig. 2,
Fig. 5 is a longitudinal sectional view showing the heat exchanger cut along the line BB in Fig. 3,
Fig. 6 is an enlarged view of the area C in Fig. 4,
Fig. 7 is a plan view showing a heating wire formed in the heat exchanger of Fig. 4,
Fig. 8 is a plan view showing a modification of the heating wire formed in the heat exchanger of Fig. 4,
9 is a schematic diagram showing a main configuration of a sanitary washing apparatus according to Embodiment 1 of the present invention,
10 is a cross-sectional view showing a heat exchanger mounted in the sanitary washing apparatus of Fig. 9,
11 is a schematic diagram showing a main configuration of a sanitary washing apparatus according to a modification of the present invention.

(Knowledge that became the basis of the present invention)

The present inventors have studied a heat exchanger in which a flow path is formed along both heat transfer surfaces of a flat plate heater.

Generally, a heat exchanger is designed on the assumption that the respective heat transfer amounts on the sides of the heat transfer surface with respect to the washing water are substantially the same. If there is a large difference in the amount of heat between the two sides, a local boiling phenomenon may occur in the flow path of one side, and bubbles may be generated. Such bubbles increase the flow resistance of the cleansing water in the flow path, the flow balance in both flow paths is broken, and the difference in total heat amount becomes larger.

In addition, a temperature sensor such as a thermistor may be provided near the outlet of the heat exchanger. In this case, when the bubbles grow large and adhere to the temperature sensor, the temperature sensor can not contact the washing water. Therefore, the temperature sensor can not be properly detected.

Further, when the bubbles adhere to the heat transfer surface and grow large, the bubbles interpose between the heat transfer surface and the cleansing water to dissociate them. In this case, it is difficult to transfer heat from the heat transfer surface to the washing water, and the temperature of the heat transfer surface increases greatly. The temperature difference between the heat transfer surface on which the bubbles adhere and the heat transfer surface on the opposite side increases. Due to the thermal stress, deformation or the like occurs in the flat plate heater, and the service life of the heat exchanger is shortened.

The most dominant factor that scale attaches to the front surface is the temperature of the front surface. Generally, in order to suppress scale adhesion, the set temperature of the heat transfer surface is set to 100 deg. C or lower, preferably 80 deg. C or lower, at which boiling occurs. The set temperature of the heat transfer surface is appropriately determined by the scale concentration of the tap water, the required duration of the heater, and the like. If a part of the heat transfer surface exceeds the set temperature, a scale is attached to the part, and the scale becomes a heat conduction failure. In order to avoid this, it is sufficient to increase the area of the heat transfer surface. However, this is undesirable because it increases the cost of the heat exchanger. It is also conceivable to set the distribution of the wattage density or the heat transfer rate of the flat plate heater so that the temperature of the heat transfer surface becomes almost uniform as a whole. In this case, the size of the heat transfer surface can be minimized, and the temperature of the heat transfer surface can be made lower than the set temperature, but the cost of the flat plate heater becomes expensive.

It is also conceivable to increase the speed of the washing water in order to suppress the generation of bubbles which cause scale or the like, or to accelerate the discharge of bubbles. In this case, the heat transfer rate from the heat transfer surface to the cleaning water is improved, and the size of the heat transfer surface can be reduced. However, in general, in the sanitary washing apparatus used for a hot water washing toilet seat, the amount of water used per washing water is small. For this reason, the thickness of the flow path must be made very thin to increase the flow rate of the washing water. Normally, the maximum value of the flow rate of the washing water is about 500 cc / min. In order to further increase the flow velocity with respect to this flow rate value, it is necessary to set the flow channel thickness within 0.5 mm. As described above, if the channel thickness is made very thin, nonuniformity of the local flow velocity tends to occur. The thickness of the flow path: 0.5 mm is smaller than the thickness of the velocity boundary layer: several millimeters, so that the velocity boundary layer covers the entire flow channel. Therefore, the velocity gradient changes depending on the thickness of the flow path, and the flow velocity is likely to vary due to unevenness in the flow path thickness.

The velocity boundary layer is a fluid layer whose velocity is zero at the heat transfer surface and whose velocity changes abruptly. Therefore, the bubbles on the heat transfer surface are weak in the force of discharging from the heat transfer surface. Further, when the channel thickness is thin, the size of the foam formed in the channel tends to become larger than the channel thickness. In this case, the bubbles are deformed corresponding to the thickness of the flow path, and a pushing force is generated by the surface tension of the bubbles, so that the bubbles are hard to move. Therefore, the bubbles stagnate in the flow passage, and the bubbles tend to locally cause unevenness of the flow velocity.

In the case of flat plate type heaters having a watt density of 30 W / cm < 2 > or more at a watt density of 30 W / cm < 2 > or more when the local flow velocity becomes uneven, the heat transfer surface temperature locally increases greatly. Boiling occurs at this point, causing more bubbles. For this reason, uneven flow is promoted, and the heat transfer surface burns out.

It is difficult to greatly increase the flow rate of the washing water because the pressure loss increases. In addition, since the speed becomes uneven, it is also difficult to reduce the thickness of the flow path. Further, if the flow path is skewed in the horizontal direction, the distance and time of the washing water flowing through the flow path is long and the flow path cross-sectional area is small, so that the flow of the washing water is likely to be blocked by the bubbles. Therefore, a meandering flow path is not preferable.

When a flat plate heater is used in a heat exchanger, the heat exchanger becomes compact and the heat transfer area can be easily increased. However, it has been difficult to generate a uniform and fast flow along the heat transfer surface by forced convection. In addition, as described above, if the thickness of the flow path is made thinner in order to generate a rapid flow along the heat transfer surface, the flow tends to become uneven. For this reason, when a partially superheated portion is generated, heat is concentrated in the superheated portion, and the washing water of this portion is evaporated to generate bubbles. If the bubble does not leak, this portion is further heated. As a result, when the air bubble becomes large and the heat transfer surface becomes extremely high, the heater is destroyed.

In order to form a thin and fast flow along the heat transfer surface, it is also conceivable to provide a flat diaphragm in the inflow portion of the flow path. However, air is easily collected at the throttling portion, and this bubble makes the flow uneven. As described above, there is also a problem in providing a flat cross-linking portion in the inflow portion of the flow path.

Further, even in the domestic water piping, air is contained in the fluid. Therefore, it is necessary to smoothly discharge bubbles such as air without collecting the bubbles in the heat exchanger.

The present invention is based on the above knowledge.

A sanitary washing apparatus according to an embodiment of the present invention includes a nozzle, a water supply path having an upstream end connected to the water supply source and having a downstream end connected to the nozzle, and a heat exchanger provided in the water supply path, The heat exchanger includes an inlet portion, an outlet portion located above the inlet portion, and a plate-like heater formed so as to communicate with the inlet portion at the lower end portion and communicate with the outlet portion at the upper end portion, A flat plate shaped heater accommodated in the heater accommodating space of the casing so as to extend in the up and down direction and including a heat transfer surface facing the main surface of the heater accommodating space; Wherein a width of the gap on the inflow portion side of the flow path space is smaller than a width of a gap on the outflow portion side, It is.

In the sanitary washing apparatus, the flat plate heater may be configured such that the heat density at the inlet side is larger than the heat density at the outlet side.

In the sanitary washing apparatus, the flat plate heater may have a ceramic base and an electric heating line formed by pattern printing on the ceramic base, and the sectional area of the electric heating line on the inlet side may be smaller than the sectional area of the electric heating line on the outlet side.

In the sanitary washing apparatus, the flat plate heater has a ceramic base and a heating wire formed by pattern printing on the ceramic base, and the spacing between the heating wires adjacent to each other on the inlet side of the heating wires adjacent to each other on the outlet side. It may be larger than the interval.

In the sanitary washing apparatus, the heat exchanger may further include an inlet port and a header section formed between the inlet port and the inlet section, and the header section may have a main flow path and a throttling flow path that gradually narrows from the main flow path toward the inflow section .

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

In addition, below, the same code | symbol is attached | subjected to the same or corresponding element through all the drawings, and the overlapping description is abbreviate | omitted.

A description will be given of a state in which the heat exchanger 10 is vertically installed so that the heat transfer surfaces 20a and 20b of the flat plate heater 20 are in the vertical direction. The Z direction shown in each figure indicates the vertical direction. The X direction is orthogonal to the vertical direction and also indicates a direction parallel to the heat transfer surfaces 20a and 20b of the flat plate heater 20. [ The Y direction indicates a direction orthogonal to both the Z direction and the X direction. The sectional area represents the area in a plane orthogonal to the flow of the washing water.

(Embodiment 1)

Fig. 9 is a schematic diagram showing the main configuration of the sanitary washing apparatus 1 according to the first embodiment.

The sanitary washing apparatus 1 includes a nozzle 7 and a water supply passage 9 having an upstream end to be connected to the water supply source 8 and having a downstream end connected to the nozzle 7, And a heat exchanger (10) provided in the heat exchanger.

10 is a cross-sectional view showing the heat exchanger 10 mounted on the sanitary washing apparatus 1 of Fig.

The heat exchanger 10 has an inlet 10a and an outlet 10b positioned above the inlet 10a and a lower end communicating with the inlet 10a and an upper outlet communicating with the outlet 10b A casing 23 including a plate-like heater accommodating space 23c formed to extend in the vertical direction and communicated with the heater accommodating space 23c of the casing 23 and accommodated to extend in the up and down direction in the heater accommodating space 23c of the casing 23, The flat plate heater 20 including the heat transfer surfaces 20a and 20b facing the main surfaces 30a and 40a of the space 23c and the flat surfaces 30a and 30b of the heat transfer surfaces 20a and 20b and the heater accommodating space 23c, And 40a, which are formed in the outer circumferential surface. The flow space 25 is formed such that the width of the gap on the inlet 10a side is smaller than the width of the gap on the outlet 10b side. Here, the " vertical direction " is a concept including both vertical directions and directions intersecting in the vertical direction. The " heater accommodating space " means a space including a region in which the heater is present and a space in contact with the heater region, assuming that the heater is removed from the casing. The " flow path space " can be referred to as a flow path formed in the casing for guiding fluid (here, water) along a pair of heat transfer surfaces of the flat plate type heater.

In the sanitary washing apparatus 1 having the above-described configuration, the washing water flows from the water supply source 8 to the water supply passage 9. The washing water flows into the heat exchanger 10 in the water feed passage 9 and is heated therein. The cleansing water which has become high temperature flows out of the heat exchanger 10 and is supplied to the nozzle 7. As a result, hot water is ejected from the nozzle 7.

In the heat exchanger 10, the washing water flows into the heater accommodating space 23c of the casing 23 from the inflow section 10a. The washing water enters between the main surfaces 30a and 40a on the plane of the heater accommodating space 23c and the heat transfer surfaces 20a and 20b of the flat plate heater 20 and passes through the flow space 25. At this time, the washing water is heated by the heat transfer surfaces 20a and 20b, and the temperature rises.

In this flow path space 25, the width of the gap on the inflow portion 10a side is smaller than the width of the gap on the outflow portion 10b side. For this reason, the washing water flowing through the flow path space 25 accelerates forced convection on the inflow portion 10a side. Here, the velocity gradient of the boundary layer with the washing water is increased from the heat transfer surfaces 20a and 20b, and the heat transfer rate is increased. Heat is applied to the washing water from the heat transfer surfaces 20a and 20b and the temperature of the heat transfer surfaces 20a and 20b is low and the scale is prevented from adhering to the heat transfer surfaces 20a and 20b.

The washing water flows from the inflow portion 10a side to the outflow portion 10b side by forced convection. Even in the outflow portion 10b side, the washing water is further heated on the heat transfer surfaces 20a and 20b. As a result, the air mixed in the washing water expands and bubbles are generated. The air bubble does not collect in the flow path space 25 and flows out to the outflow portion 10b because the width of the gap on the outflow portion 10b side is large.

Further, as the temperature of the washing water rises and the density thereof becomes smaller, an upward flow of natural convection occurs and the washing water flows to the outlet 10b. Since the width of the gap on the outflow portion 10b side is large, bubbles are easily excluded by the upward flow of natural convection, and the heat transfer rate from the heat transfer surfaces 20a, 20b to the washing water is improved.

According to the sanitary washing apparatus 1 having the above configuration, the bubbles are reliably discharged by the bubbles, so that the heat exchange between the washing water and the heat transfer surfaces 20a and 20b is stably performed.

Also, the bubbles stagnate in a part of the washing water, and the generation of the scale locally is reduced. Therefore, since the scale flows smoothly without narrowing the flow path space 25, the required amount of washing water can be secured.

Further, air bubbles do not adhere to the heat transfer surfaces 20a and 20b, and this portion becomes a high temperature, thereby preventing temperature differences on the heat transfer surfaces 20a and 20b. Thus, it is possible to prevent the heat transfer surfaces 20a and 20b from being deformed or damaged by thermal stress due to the temperature difference, and to prevent the plate heater 20 from failing.

(Embodiment 2)

[Configuration of sanitary washing apparatus]

Fig. 1 shows a toilet equipped with the sanitary washing apparatus 1 according to the second embodiment in the toilet 2.

The sanitary washing apparatus (1) is disposed on the upper surface of the toilet bowl (2). The sanitary washing apparatus 1 is provided with a main body 3, a toilet seat 4, a toilet lid 5 and an operating portion 6.

The body portion 3 is disposed on the rear side of the toilet seat portion 4, that is, on the rear side as viewed from a seated user. The main body 3 accommodates the water supply passage 9 and the heat exchanger 10 shown in Fig. 9 in the transverse-section housing 3a. In addition to these, the main body 3 houses a cleaning unit, a drying unit (not shown), a control unit for controlling these operations, and the like.

The water supply line 9 introduces tap water (fluid, liquid, washing water) from the water supply facility (water supply source 8) attached to the installation building of the toilet 2 to the nozzle 7 via the heat exchanger 10 do. When the user operates the operation unit 6 to execute a predetermined input, the cleaning unit is driven. The washing water is heated in the heat exchanger 10 and hot water is discharged from the nozzle 7 in the form of a shower toward the opening of the toilet 2.

[Configuration of Heat Exchanger]

2 is a plan view showing the front surface of the heat exchanger 10. Fig. 3 is a plan view showing the right main surface of the heat exchanger 10; 4 is a cross-sectional view showing the heat exchanger 10 cut along the line A-A in Fig. 5 is a longitudinal sectional view showing the heat exchanger 10 cut along the line B-B in Fig. Fig. 6 is an enlarged view of the area C in Fig.

The heat exchanger 10 has a small thickness dimension in the Y direction and a rectangular shape in the X-Z direction. As shown in Fig. 4, the heat exchanger 10 includes a flat plate heater 20, a first flow path forming member 21, and a second flow path forming member 22. As shown in Fig.

The casing (23) is formed by the first flow path forming member (21) and the second flow path forming member (22). The first flow path forming member 21 and the second flow path forming member 22 are each formed of, for example, a reinforced ABS resin in which ABS resin is compounded with glass fiber.

The first flow path forming member 21 is disposed on the first heat transfer surface 20a side of the flat plate heater 20. The first flow path forming member 21 includes a base portion 30 and a shelf end portion 31. The base portion 30 includes a base surface (main surface) 30a, and the base surface 30a is planar and opposes the first heat transfer surface 20a. In the shelf end portion 31, the thickness of the base portion 30 in the Y direction is changed. The thickness of the base portion 30 on the outlet 10b side of the shelf 31 is smaller than the shelf 31 on the side of the inlet 10a. The base surface 30a on the inlet 10a side of the shelf end 31 is closer to the first heat transfer surface 20a than the base surface 30a on the outlet 10b side. The width between the base surface 30a at the inlet 10a side and the first heat conductive surface 20a is narrower than the width between the base surface 30a at the outflow portion 10b side and the first heat conductive surface 20a.

The first flow path forming member 21 is provided with a wall-like flange portion 32 around the entire periphery of the base portion 30. A coupling groove 33 is formed at the front end of the flange portion 32 and the coupling groove 33 is formed around the entire periphery of the flange portion 32.

The second flow path forming member 22 is disposed on the second heat transfer surface 20b side of the flat plate heater 20. The second flow path forming member 22 includes a base portion 40 and a shelf end portion 41. The base portion 40 includes a base surface (main surface) 40a, and the base surface 40a is planar and opposes the second heat transfer surface 20b. In the shelf end portion 41, the thickness of the base portion 40 in the Y direction is changed. The thickness of the base portion 40 on the side of the outlet portion 10b is smaller than the side of the inlet portion 10a than the shelf end portion 41 on the side of the outlet portion 10b. The base surface 40a on the inflow portion side of the shelf end portion 41 is closer to the second heat transfer surface 20b than the base surface 40a on the outflow portion 10b side. The width between the base surface 40a and the second heat conductive surface 20b on the side of the inlet 10a is narrower than the width between the base surface 40a and the second heat conductive surface 20b on the outflow portion 10b side.

The second flow path forming member 22 is provided with a wall-like flange portion 42 around the entire periphery of the base portion 40. The flange portion 42 projects toward the opposite side of the base surface 40a. The front end portion of the flange portion 42 is turned over to the base surface 40a side. A coupling protrusion 43 is provided at the end of the tip end, and a coupling protrusion 43 is formed around the entire periphery of the flange portion 42.

The flange portion 42 of the second flow path forming member 22 is inserted into the flange portion 32 of the first flow path forming member 21 and the flange portion 42 of the second flow path forming member 22 is inserted into the coupling groove 33 of the first flow path forming member 21, The engaging projection 43 of the forming member 22 is fitted. For example, the engaging projections 43 are fixed to the engaging grooves 33 by ultrasonic welding. As a result, the first flow path forming member 21 and the second flow path forming member 22 are joined together in a watertight manner, and the casing 23 is formed.

The casing 23 has two side surfaces, two main surfaces, a ceiling surface and a bottom surface, and includes a substantially rectangular hollow portion surrounded by these. This substantially rectangular hollow portion constitutes a plate-like heater accommodating space 23c. The heater accommodating space 23c extends in the vertical direction. The lower end portion of the heater accommodating space 23c communicates with the inflow portion 10a and the upper end portion communicates with the outflow portion 10b. The inlet port 23a and the outlet port 23b open in one side surface among two side surfaces of a Y-Z direction. And the opening of the outlet 23b becomes the outlet 10b. The inlet 23a is provided at one lower end of the side surface and is connected to the upstream end of the water supply passage 9 (Fig. 9). The outlet 23b is provided at the upper end of one side of the side face and is connected to the downstream end of the water supply passage 9 (Fig. 9). Two main surfaces in the X-Z direction are formed on the base surfaces 30a and 40a, respectively. The ceiling surface is opposed to the upper end of the flat plate shape heater 20. The ceiling surface is inclined so that the gap between the ceiling surface and the upper end of the flat plate heater 20 becomes wider as it approaches the outlet 23b. The bottom surface faces the lower end of the flat plate shape heater 20. The inflow part 10a of the flow path space 25 opens in the ceiling surface, and the inflow part 10a extends in the X direction. A channel space (25) and a header portion (45) are formed in the casing (23).

The flow path space 25 includes a flow path between the first heat transfer surface 20a and the base surface 30a and a flow path between the second heat transfer surface 20b and the base surface 40a. These two flow paths are formed symmetrically on both sides of the flat plate-like heater 20. The two flow paths each have an inlet-side flow passage 25a and an outlet-side flow passage 25b. The inlet-side flow path 25a is provided on the side closer to the lower inlet / outlet 23a than the shelf end portions 31, 41. The outlet-side flow path 25b is provided on the side closer to the outlet port 23b than the shelf end portions 31 and 41. [ The thickness of the inlet-side flow path 25a in the Y-axis direction is smaller than the thickness of the outlet-side flow path 25b in the Y-axis direction.

The header portion 45 is provided between the inlet portion 10a of the flow path space 25 and the inlet port 23a and extends in the X direction as shown in Fig. The header portion 45 includes a header portion main flow path 45a and a header portion throttling flow path 45b. The cross-sectional area of the flow path in the X-Y direction in the header portion main flow path 45a is wider than that in the header portion throttling flow path 45b. That is, the cross-sectional area of the passage in the X-Y direction is orthogonal to the flow of the washing water flowing from the inlet 23a to the inlet 10a. The flow path cross-sectional area of the header portion interflow channel 45b gradually narrows from the header portion main flow path 45a toward the inflow portion 10a from the inflow portion 10a. The header portion communication oil passage 45b has a crank shape. The header portion interfacing flow passage 45b includes a vertical portion 45bb, a horizontal portion 45bc, and a vertical portion 45bd. The cross-sectional area of the vertical portion 45bb, the horizontal portion 45bc, and the vertical portion 45bd becomes smaller (that is, becomes narrower).

The flat plate heater 20 is accommodated in the heater accommodating space 23c of the casing 23 and extends in the vertical direction. The flat plate heater 20 has a rectangular flat plate shape and includes first and second heat transfer surfaces 20a and 20b on both surfaces thereof. The flat plate heater 20 includes a ceramic base 20k, a resistor pattern 20p, and an electrode (not shown). The temperatures of the heat transfer surfaces 20a and 20b are prevented from becoming locally higher than the predetermined temperature. This predetermined temperature is generally set to 100 deg. C or less, preferably 80 deg. C or less, at which the temperature of the heat transfer surfaces 20a, 20b is boiled. The predetermined temperature is appropriately determined by the scale concentration of the tap water, the required duration of the heater, and the like.

In the resistor pattern 20p, a resistor is printed on the ceramic base 20k. The resistor pattern 20p constitutes a heating wire (heater wire) and generates heat by energization from the electrode. As shown in Fig. 7, the heater wire extends in the X direction and meanders and extends upward in the Z direction. The width 20s of the heater wire in the inlet side flow path 25a is thinner than the width 20s of the heater wire in the outlet side flow path 25b and the sectional area of the heater wire is small. The smaller the width 20s of the heater wire and the smaller the cross-sectional area of the heater wire, the greater the resistance value of the heater wire. Therefore, the resistance value of the heater wire in the inlet-side flow path 25a is higher than the resistance value of the heater wire in the outlet-side flow path 25b. The heat generating density in the resistive pattern 20p in the inlet side flow path 25a is higher than the heat generating density in the resistive pattern 20p in the outlet side flow path 25b.

[Flow of rinsing water in the sanitary washing apparatus]

As shown in Fig. 9, when the solenoid valve is opened, the washing water flows from the water pipe of the water supply source 8 to the water feed passage 9 via the diverging water cap. As shown in Figs. 3 and 4, the washing water flows into the casing 23 from the water feed passage 9 via the inlet 23a.

4 to 6, the washing water enters the header portion main flow path 45a of the header portion 45. As shown in Fig. The resistance from the header portion main flow path 45a to the header portion flow path 45b is smaller than the cross sectional area of the header portion main flow path 45a because the cross sectional area of the header portion flow path 45b is much smaller than the cross sectional area of the header portion main flow path 45a, Direction is larger than the resistance in the X direction. Therefore, a considerable number of the washing water flows in the X direction of the header main flow path 45a, and the washing water uniformly fills the header main flow path 45a. Then, the washing water flows from the header main flow passage 45a to the header portion throttling flow passage 45b. Since the flow path cross-sectional area of the header portion throttling flow passage 45b is gradually narrowed, the flow of the washing water gradually becomes faster. Further, there is no place where air stays in the header portion throttling flow path 45b. Therefore, even if air is mixed into the cleansing water, the air is transferred toward the inlet 10a without aggregation. When the washing water flows from the inflow section 10a to the inlet-side flow path 25a, the bubbles rise smoothly by the buoyancy along the flow path space 25 in the vertical direction. Further, the bubbles flow to the outflow portion 10b along the ceiling of the casing 23 rising toward the outflow portion 10b. Then, the bubbles are discharged from the outflow portion 10b to the outside through the outlet port 23b.

As shown in Fig. 4, the washing water flows into the inlet-side flow path 25a of the flow path space 25 from the inlet portion 10a. The flow velocity of the washing water is faster in the inlet-side flow path 25a, which is a thin region of the flow path thickness. Therefore, the velocity gradients of the boundary surfaces between the heat transfer surfaces 20a and 20b of the flat plate heater 20 and the cleansing water are large and the heat transfer rate between the heat transfer surfaces 20a and 20b and the cleansing water is large. In addition, in each of the heat transfer surfaces 20a and 20b, the heat density in the resistive pattern 20p at the inlet-side flow path 25a is high. Therefore, the washing water is heated by the heat transfer surfaces 20a and 20b to become high temperature, and the density thereof is reduced. As a result, the washing water rises and flows from the inlet-side flow passage 25a to the outlet-side flow passage 25b.

In addition, since the heat generating density in the resist pattern 20p in the inlet-side flow path 25a is high, the temperatures of the heat transfer surfaces 20a and 20b are intended to be increased. However, since the temperature of the washing water in the inlet-side flow path 25a is low, the subcool (cooling degree with respect to the boiling temperature of the water) becomes large, and the washing water absorbs a large amount of heat from the heat transfer surfaces 20a and 20b. Further, in the inlet-side flow path 25a, the flow path thickness is thin and the flow rate of the washing water is high. Therefore, the washing water has a high heat transfer rate, and does not reach a high temperature at which local boiling phenomenon occurs.

In addition to the forced convection in the inlet-side flow path 25a, the outlet-side flow path 25b also has natural convection due to the difference in density. As a result, the washing water rises along each of the heat transfer surfaces 20a and 20b. Since this washing water is heated in the inlet-side flow path 25a, the temperature is high. By this cleaning water, less heat is taken from each of the heat transfer surfaces 20a, 20b, and the value of the subcool is small. Therefore, the temperatures of the heat transfer surfaces 20a and 20b in the outlet-side flow path 25b are likely to rise. However, since the heat-generating density at the outlet-side flow path 25b is small, the temperature of the washing water gradually rises as it approaches the outlet 23b, but does not cause rapid boiling. This prevents the scale from adhering to a part of each of the heat transfer surfaces 20a, 20b.

Further, even if air bubbles are generated on the respective heat transfer surfaces 20a, 20b, the air bubbles rise along the outlet-side flow path 25b with a thicker flow path thickness in the outlet-side flow path 25b. Then, the bubbles are discharged from the outlet port 23b.

The high-temperature washing water thus flows into the water feed passage 9 from the outlet port 23b. The temperature of the washing water is adjusted by a tank (not shown) or the like. When the solenoid valve is opened, warm washing water is discharged from the nozzle 7.

[effect]

The flow rate of the header portion is gradually increased by the header portion throttling flow path 45b whose sectional area is gradually narrowed. Therefore, even when air is mixed into the water pipe, the bubbles are extruded downstream and quickly discharged from the header portion 45 and the flow path space 25 before the bubbles grow large. As a result, the flow of the washing water on each of the heat transfer surfaces 20a, 20b is made non-uniform by the air bubbles, and the heat transfer surfaces 20a, 20b are prevented from locally becoming overheated. Therefore, the scale is locally attached to each of the heat transfer surfaces 20a, 20b to prevent the flow path from being narrowed. Thus, a necessary flow rate is secured. Further, due to the temperature difference between the heat transfer surfaces 20a and 20b due to the scale, it is avoided that the plate heater 20 is broken due to thermal stress.

In addition, since the header portion throttling flow path 45b has a crank shape, the flow path in the header portion throttling flow path 45b becomes longer. Therefore, even if the cross-sectional area in the header portion throttle passage 45b is slightly wider, the passage resistance in the header portion throttle passage 45b can be ensured. As a result, the washing water can flow uniformly into the header portion throttling flow path 45b at the entire length of the header portion main flow path 45a.

Uniform flow of the washing water along the heat transfer surfaces 20a and 20b in the flow path space 25 is formed by the header portion interfacing flow path 45b. As a result, the heat transfer rate of each of the heat transfer surfaces 20a and 20b and the washing water increases. Therefore, the washing water can be efficiently heated. In addition, it is possible to suppress the temperature of each of the heat transfer surfaces 20a, 20b to be low, and to prevent the scale from adhering to the heat transfer surfaces 20a, 20b. Further, bubbles generated on the respective heat transfer surfaces 20a, 20b are liable to be released, generation of a local scale and breakage of the flat plate heater 20 due to thermal stress are prevented, and the heat transfer surfaces 20a, The heat exchange of the washing water is not inhibited, and stable heat exchange becomes possible.

Particularly, the inlet-side flow passage 25a is close to the header portion communication flow passage 45b and the flow passage thickness is thin. Therefore, in the inlet-side flow path 25a, a fast flow from the header portion throttling flow path 45b is maintained. Therefore, the velocity gradient in the boundary layer between each of the heat transfer surfaces 20a and 20b and the washing water is large and the heat transfer rate due to the forced convection of the washing water to the heat transfer surfaces 20a and 20b is large. The washing water is efficiently heated, and breakage of the flat plate heater 20 is prevented.

Since the heat transfer densities of the heat transfer surfaces 20a and 20b in the outlet-side flow path 25b are small, local boiling phenomenon is prevented, and breakage of the flat plate heater 20 is prevented.

Further, since the flat plate heater 20 heats the washing water by the heat transfer surfaces 20a and 20b on both sides of the front and back surfaces, there is almost no heat loss loss. Therefore, it is possible to realize a high thermal efficiency of the heat exchanger 10 and to make it compact.

In addition, even in the outlet-side flow path 25b, the flat plate heater 20 is suppressed from becoming a high temperature to such a degree that local boiling phenomenon occurs, and generation of a local scale is prevented. Therefore, even if the ceramic is used for the flat plate heater 20, heat dissipation is small, and the thermal capacity is smaller than that of metal. However, if the ceramic is used for the flat plate heater 20, the division can be prevented and the sanitary washing apparatus 1 can be prolonged.

Even if bubbles are generated due to a large difference in the amount of heat transfer between the two heat transfer surfaces 20a and 20b in the flat plate heater 20 and the rinsing water of one of the two flow paths is locally boiled, Is smoothly discharged. Therefore, it is prevented that the flow path resistance of the washing water becomes high, the flow balance of the two flow paths is collapsed, or a large difference in the heat transfer amount of the two flow paths is prevented.

In addition, even if a temperature sensor such as a thermistor is disposed in the vicinity of the outflow portion 10b of the flow path space 25, the temperature sensor can appropriately detect the temperature. That is, since the bubbles are discharged, the bubbles do not increase. Therefore, a situation in which large bubbles adhere to the temperature sensor and the temperature sensor can not detect the temperature of the washing water due to the large bubbles not contacting the washing water is avoided.

Further, due to the forced convection of the washing water and the discharge of the bubbles, the scale is prevented from adhering to the heat transfer surfaces 20a and 20b. Thereby, it is not necessary to increase the area of heat transfer surfaces 20a and 20b in order to avoid heat transfer trouble due to scale. Therefore, the cost of the sanitary washing apparatus 1 can be prevented from increasing, and the sanitary washing apparatus 1 can be made more compact.

In addition, the cross-sectional area of the header portion interflow channel 45b is gradually narrowed, and the cross-sectional area of the inlet-side channel 25a in the channel space 25 is narrower than that of the outlet- As a result, uniform flow of the washing water along each of the heat transfer surfaces 20a and 20b is formed without reducing the thickness of the flow path.

Further, forced convection occurs due to the header portion throttling flow passage 45b whose sectional area is gradually narrowed and the inlet-side flow passage 25a whose sectional area is narrow, so that the air bubbles on the heat transfer surfaces 20a and 20b are quickly pushed upward. In addition, even in the case of the outlet-side passage 25b having a large cross-sectional area, even large bubbles can easily move. Therefore, the bubbles are quickly discharged to the outside. As a result, the flow of the washing water becomes uniform.

The heat transfer density of each of the heat transfer surfaces 20a and 20b is smaller than that of the inlet-side flow passage 25a. On the other hand, the flow velocity of the washing water is larger in the inlet-side flow passage 25a than in the outlet-side flow passage 25b. Therefore, the heat flow rate of each of the heat transfer surfaces 20a and 20b is higher than that of the outlet-side flow path 25b. This makes it possible to uniformize the temperatures of the heat transfer surfaces 20a and 20b, thereby suppressing the scale from locally adhering.

[Other examples]

In the second embodiment, as shown in Fig. 7, the width 20s of the heater wire in the inlet-side flow path 25a is made narrower than the width 20s of the heater wire in the outlet-side flow path 25b have. However, if the heat density in the resist pattern 20p in the inlet-side flow path 25a becomes higher than the heat density in the resist pattern 20p in the outlet-side flow path 25b, But is not limited to the line width 20s.

For example, as shown in Fig. 8, in the resistor pattern 20p, the interval 20h between adjacent heater wires in the inlet-side flow path 25a is narrower than the outlet-side flow path 25b. Thus, the heat generating density in the resistive pattern 20p in the inlet-side flow path 25a is higher than the heat generating density in the resistive pattern 20p in the outlet-side flow path 25b.

In the second embodiment, the header portion throttling flow path 45b has a substantially crank shape, and the flow path cross-sectional area thereof is gradually narrowed. The shape of the header portion interflow channel 45b is not limited to the crank. For example, a header portion throttling flow path may be formed in an end surface of an approximately " " shape formed by two sides of the vertical portion 45bb and the horizontal portion 45bc shown in Fig. Further, the present invention is not limited to the stepwise narrowing of the flow path cross-sectional area. For example, as shown in Fig. 11, a header portion throttling flow path may be formed in a triangular-shaped cross section whose distance toward the top is narrowed. In this case, the cross-sectional area of the flow passage is gradually narrowed.

In the second embodiment, the thicknesses of the base portions 30 and 40 in the Y direction are gradually changed by the shelf end portions 31 and 41 in the members 21 and 22, respectively. As a result, two flow paths 25a and 25b having different sectional areas are provided in the flow path space 25. On the other hand, as shown in Fig. 11, the members 21 and 22 may be formed so that the thickness of the base portions 30 and 40 in the Y direction is gradually changed. In this case, the flow path space 25 is provided with one flow path whose cross sectional area gradually changes.

Further, the above-mentioned entire embodiments may be combined with each other unless excluding each other.

From the above description, it will be apparent to those skilled in the art that many modifications and other embodiments of the present invention are possible. Accordingly, the above description should be construed as illustrative only, and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the invention. The details of the structure and / or the function can be substantially changed without departing from the spirit of the present invention.

[Industrial Availability]

The sanitary washing apparatus of the present invention is useful as a sanitary washing apparatus or the like capable of securing a required flow rate of washing water and preventing a failure.

1: Hygienic cleaning device 7: Nozzle
8: Water source 9: Water source
10: Heat exchanger 10a:
10b: outlet portion 20: flat plate heater
20a: First heat-transferring surface (heat-transferring surface) 20b: Second heat-transferring surface (heat-transferring surface)
20k: ceramic base 20p: pattern (heating wire)
23: casing 23a: inlet
25: channel space 30a: base surface (main surface)
40a: base surface (main surface) 45: header portion
45a: header main flow path (main flow path) 45b: header portion throttling flow path (throttle flow path)

Claims (5)

And a heat exchanger having an upstream end connected to the water supply source and having a downstream end connected to the nozzle, and a heat exchanger provided in the water feed path,
The heat exchanger,
And an inlet portion, an outlet portion located above the inlet portion, a lower end portion communicating with the inlet portion, an upper end portion communicating with the outlet portion, and a plate-shaped heater accommodating space formed to extend in the vertical direction. Casing,
A flat plate-shaped heater accommodated in the heater accommodating space of the casing so as to extend in the vertical direction and including a heat transfer surface facing the main surface of the heater accommodating space;
And a flow path space formed in a gap between the heat transfer surface and the main surface of the heater accommodating space,
The flow path space is formed such that the width of the gap on the inlet side is smaller than the width of the gap on the outlet side.
Hygienic cleaning device. The method of claim 1,
And the flat plate heater is configured such that the heat density at the inlet side is larger than the heat density at the outlet side
Hygienic cleaning device. 3. The method according to claim 1 or 2,
Wherein the flat plate heater has a ceramic base body and a heating wire formed by pattern printing on the ceramic base body,
Sectional area of the heating wire on the inflow portion side is smaller than a cross-sectional area of the heating wire on the outflow portion side
Hygienic cleaning device. 3. The method according to claim 1 or 2,
Wherein the flat plate heater has a ceramic base body and a heating wire formed by pattern printing on the ceramic base body,
The spacing of the heating wires adjacent to each other on the inlet side is greater than the spacing of the heating wires adjacent to each other on the outlet side.
Hygienic cleaning device. The method according to any one of claims 1 to 4,
The heat exchanger further has an inlet and a header portion formed between the inlet and the inlet,
The header portion has a main flow passage and a throttle flow passage gradually narrowing from the main flow passage toward the inflow portion.
Hygienic cleaning device.

Images