JP3936589B2 - Hot water storage tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water storage tank equipped in a beverage supply machine or the like, and more particularly to a hot water storage tank having a function capable of effectively removing scale accumulated on the bottom surface of the tank.
[0002]
[Prior art]
For example, a hot water storage tank equipped in a tea machine has a structure in which a drain outlet provided with an opening / closing valve is opened at the center of the bottom surface of the tank body, and a heater is provided around the opening. When water is supplied into the tank body in the closed state, hot water is generated and stored by being heated by the heater, and when the pouring switch is operated, it is directed from the discharge port to the tea generation unit, etc. It is designed to be discharged.
By the way, in such a hot water storage tank, when water containing a large amount of calcium ions or the like is used as raw water, a scale is generated and deposited on the bottom surface of the tank body. If the accumulated scale is left as it is, it floats due to convection in the tank that occurs during heating, etc., and enters the dispensing valve during dispensing, causing malfunctions, and worsening the taste of tea and white water There was a fear.
In addition, if the scale is deposited on the heater installation area, bubbles generated near the heater installation area when the hot water boils up or disappears as they try to float out of the scale. As a result, there was a problem that abnormal noise was generated from the bottom of the tank.
[0003]
[Problems to be solved by the invention]
Therefore, it is necessary to clean the inside of the tank appropriately. However, it has been negligent or delayed, and the above-mentioned problems have to be accepted.
When cleaning, stop the tea machine, wash the tank while draining, then wait for a long time before reusing it, such as adding new water and boiling water again. Because it is necessary, it was necessary to select a time zone in which the tea machine is not used frequently, which also caused the cleaning work to be delayed.
The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a hot water storage tank having a function capable of efficiently removing the generated scale.
[0004]
[Means for Solving the Problems]
As a means for achieving the above object, the invention of claim 1 is characterized in that a drain outlet provided with an on-off valve is opened at the center of the bottom surface of the tank body, and a heater is provided around the outlet. In the hot water storage tank in which the water supplied to is heated by the heater and stored as hot water and discharged from the discharge port, the bottom surface of the tank body is formed in a truncated cone shape with the top surface as an opening. The convection facilitating plate is characterized in that the opening is positioned directly above the drain and the hem portion is disposed with a predetermined dimension floating above the bottom surface.
[0005]
According to a second aspect of the present invention, in the apparatus according to the first aspect, the heater is arranged in a circular shape with a predetermined radius, while the convection promoting plate is formed with an annular horizontal portion at the periphery of the bottom of the conical portion. And the skirt of the conical portion is characterized in that it is set to be located on the outer side in the radial direction with respect to the heater.
According to a third aspect of the present invention, in the first or second aspect of the present invention, a plurality of notches are formed along a circumferential direction at a lip of the opening in the convection promoting plate. Has characteristics.
[0006]
According to a fourth aspect of the present invention, there is provided the method according to any one of the first to third aspects, wherein an annular horizontal portion is formed around a hem of the conical portion of the convection promoting plate. Legs are formed by punching out three or more spherical bosses on the back surface, and these legs are placed on the bottom surface of the tank body, so that the hem portion of the convection promoting plate floats from the bottom surface and is supported. It has the characteristics where it is done.
The invention according to claim 5 is characterized in that, in the invention according to claim 4, four or more of the legs of the convection promoting plate are provided and a part thereof has a different height.
[0007]
According to a sixth aspect of the present invention, in the apparatus according to any one of the first to third aspects, a suspending device is provided on the lid plate attached to the tank body, and the convection promotion is performed by the suspending device. The plate is characterized in that it is suspended and supported in a state where a hem portion of the plate is floated from the bottom surface by a predetermined dimension.
According to a seventh aspect of the present invention, in the apparatus according to the sixth aspect, a receiving portion is provided at a lower end of the hanging tool, and the receiving portion receives the back surface of the hem portion of the convection promoting plate while receiving the skirt. Characterized by being fixed to the part.
[0008]
[Action and effect of the invention]
<Invention of Claim 1>
In the state where the convection promotion plate is arranged on the bottom of the tank body, when the stored water is heated by the heater, the hot water in the upper part of the tank body flows down along the inner peripheral surface, and then convection is promoted from the gap at the hem. Convection occurs such that it enters the lower surface side of the plate, flows along the conical portion, and then exits from the opening on the top surface and ascends the central portion in the tank body.
Here, when the scale is accumulated on the bottom surface of the tank body, especially on the lower surface side of the convection promoting plate, the convection from the peripheral part to the center part is promoted, and the convection is pushed. By being pushed by air bubbles that move with convection, the scale is gradually brought closer to the central part and dropped into a drain outlet provided in the central part of the bottom surface. This scale is quickly discharged out of the machine by opening the drain opening / closing valve.
That is, with a simple means such as arranging a convection promoting plate, the scale accumulated on the bottom surface of the tank body can be dropped into the drain outlet and eliminated, and the bottom surface of the tank body can be kept clean.
[0009]
<Invention of Claim 2>
Bubbles generated in the vicinity of the heater installation position act so as to rise toward the center along the lower surface of the conical portion of the convection promoting plate, and the scale is reliably brought closer to the center of the bottom surface.
<Invention of Claim 3>
By forming a notch at the lip of the opening of the convection promoting plate, large bubbles passing through the plate are crushed and reduced, and even if the scale rises with the bubbles, the amount can be reduced.
[0010]
<Invention of Claim 4>
The convection promoting plate is supported in a state where the legs are placed on the bottom surface of the tank main body and floated by a predetermined dimension from the bottom surface. In particular, since the legs are formed of spherical bosses and supported by so-called points, crevice corrosion is prevented from occurring.
<Invention of Claim 5>
Since the support of the convection promoting plate becomes unstable by changing the height of the leg, the convection promoting plate rotates while being lifted by the influence of convection and bubbles, and as a result, the contact position with the bottom surface of the leg is frequently By changing, crevice corrosion becomes more difficult.
[0011]
<Invention of Claim 6>
As the tank body is covered with the lid plate, the convection promoting plate is supported in a state of being floated by a predetermined dimension from the bottom surface of the tank body via the hanging tool.
Since the convection promoting plate has no structure in contact with the bottom surface of the tank body, there is no possibility of erosion corrosion due to crevice corrosion or scratches. Since the convection promoting plate can be handled integrally with the lid plate, the arrangement and removal work can be simplified.
<Invention of Claim 7>
When the convection promoting plate is suspended, it is fixed after being received by the receiving part of the hanging tool, so that even if the fixing is lost, the convection promoting plate is prevented from falling on the bottom surface of the tank body. It is.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the hot water storage tank 10 equipped in the tea machine is illustrated. The tea or white water pouring system in this tea dispenser will be briefly described with reference to FIG. 1. Raw water such as tap water is supplied into the hot water storage tank 10 through the water supply pipe 11, and this raw water is heated by the heater plate 29. When the tea or white water pouring switch is operated, the hot water discharged from the discharge port 23 is supplied to the mixing container 13 by opening the corresponding hot water supply valve 12 in the case of tea. The tea is mixed with the powdered tea discharged from the canister 14 and is poured out from the spout 15. On the other hand, in the case of white hot water, the corresponding hot water supply valve 12 is opened and discharged from the discharge port 23. The hot water thus poured is directly poured out from the other spout 16 as white hot water.
[0013]
Next, the structure of the hot water storage tank 10 will be described. The hot water storage tank 10 includes a tank body 20 made of stainless steel plate, and the tank body 20 is formed in a bottomed cylindrical shape having a diameter X of 180 mm as shown in FIGS. Is covered with a cover plate, and the outer surface is covered with a heat insulating wall 21. A water supply port 22 connected to the water supply pipe 11 is provided on the upper side of the peripheral surface of the tank body 20, and the discharge port 23 is provided on the lower side of the peripheral surface.
A drain pipe 25 having an inner diameter Y of 15 mm is suspended and connected to the center of the tank body 20, and an open / close valve 26 is interposed in the drain pipe 25 and a connected drain hose (not shown). )) Is led out to the drainage area outside the aircraft. Further, an aluminum heater plate 29 in which a heater wire 28 is cast is stretched on the outer bottom surface of the tank body 20, and the heater wire 28 has a diameter Z as shown by a chain line in FIG. It is arranged in a 130 mm circle.
[0014]
Now, the convection promoting plate 30 is placed on the bottom surface 20A of the tank body 20 described above. The convection promoting plate 30 is formed by press molding using a stainless steel plate as a base material, and as shown in FIGS. 4 and 5, is formed in a flat truncated cone shape with the top surface as an opening 31. An annular horizontal portion 33 is formed at the periphery of the bottom of the conical portion 32.
More specifically, the convection promoting plate 30 has an overall diameter A including the horizontal portion 33 of 160 mm, which is substantially equal to the diameter of the planar portion excluding the corner R portion 20R of the bottom surface 20A of the tank body 20. Yes. As will be described in detail later, this is set in consideration of the fact that the water flowing down along the inner peripheral surface 20B of the tank body 20 tends to wrap around the lower surface side of the convection promoting plate 30.
[0015]
The angle α formed with the horizontal surface of the conical portion 32 is set to 10 to 20 degrees as shown in FIG. This is particularly set in consideration of effectively moving the bubble b generated near the position where the heater wire 28 is disposed toward the center side and smoothly directing the flow entering from the periphery toward the center side. Yes.
The width B of the horizontal portion 33 is set to about 20 mm. In other words, the bottom of the conical portion 32 is located outside the position where the heater wire 28 is disposed. This is intended to allow the bubbles b to smoothly escape to the opening 31.
[0016]
The opening 31 on the top surface is at the center, and is placed directly above the drain pipe 25 when placed on the bottom surface 20A of the tank body 20. When the diameter C of the opening 31 is too small, the bubbles (b) are concentrated and clogged, so that the flow (convection) tends to deteriorate. The distance becomes short and the bubbles b cannot be moved effectively.
Therefore, in consideration of both, it is set to about 1/5 of the diameter X of the entire convection promoting plate 30 and about 30 mm which is not significantly different from the inner diameter Y (15 mm) of the drain pipe 25.
A plurality of (in the figure, 12) slits 35 are radially cut at the rim of the opening 31 at equal angular intervals. For example, as shown in comparison with FIG. 14, if there is no slit in the opening 1, there is a possibility that a large bubble b is lifted as it is from the opening 1, but as shown in FIG. When provided, it functions to crush the large bubbles b that emerge from the opening 31.
[0017]
Three legs 37 are formed on the lower surface of the horizontal portion 33 at equal angular intervals. The leg 37 is formed by striking a spherical boss toward the lower surface, and has a height D of about 3 mm. In other words, when the convection promoting plate 30 is placed on the bottom surface 20A of the tank body 20, the distance between the horizontal portion 33 and the bottom surface 20A can be narrowed. Is intended to be.
[0018]
Next, the operation of this embodiment will be described. The convection promoting plate 30 having the above structure is placed on the bottom surface 20 </ b> A of the tank body 20. As described above, the convection promoting plate 30 is placed in a state where the periphery of the convection promoting plate 30 is spaced from the inner peripheral surface 20B of the tank body 20 by about 10 mm and the horizontal portion 33 is lifted from the bottom surface 20A by about 3 mm. The opening 31 on the top surface is located immediately above the drain pipe 25.
In this state, when the water supplied into the tank body 20 is heated by the heater plate 29, the hot water in the upper part of the tank body 20 flows down along the inner peripheral surface 20B as shown by the arrow in FIG. After that, it flows from the peripheral edge of the horizontal portion 33 of the convection promoting plate 30 to its lower surface side, vigorously moves toward the center portion, and further flows along the lower surface of the conical portion 32, and then exits from the opening portion 31 on the top surface and enters the tank body Convection occurs such that the central part in 20 rises. Further, the bubble b generated near the position where the heater wire 28 is disposed acts so as to rise toward the center along the lower surface of the conical portion 32.
[0019]
Therefore, when the scale S is accumulated on the bottom surface 20A of the tank body 20, the convection from the peripheral edge to the center is promoted, particularly on the lower surface side of the convection promoting plate 30, so that the convection is pushed. Is pushed by the bubbles b moving in the same direction, the accumulated scale S is gradually brought closer to the center as shown in FIG. 3, and dropped into the drain pipe 25 opened at the center of the bottom surface 20A. The scale S is quickly discharged out of the machine together with the drainage by opening the on-off valve 26 provided in the drainage pipe 25.
The time when the convection promoting plate 30 is placed may be only an appropriate time when the scale S is considered to have accumulated to some extent, or may be always placed.
[0020]
As described above, in this embodiment, the scale S deposited on the bottom surface 20A of the tank body 20 is dropped into the drain pipe 25 and removed by simple means such as placing the convection promoting plate 30 on the bottom surface 20A of the tank body 20. The bottom surface 20A of the tank body 20 can be kept clean. As a result, when the tea or white hot water is poured out, the scale S is prevented from being mixed, the influence on the flavor of the hot water tea is eliminated, and the hot water supply valve 12 and the like are prevented from being clogged. Further, by removing the scale S accumulated in the vicinity of the position where the heater wire 28 is disposed, it is possible to prevent the generation of noise due to the bubbles b floating out of the scale S or disappearing. If the convection promoting plate 30 is always placed, the deposition of the scale S itself is suppressed.
[0021]
Further, by placing the convection promoting plate 30, foreign matters other than the scale S can be removed from the drain pipe 25, and the convection in the tank body 20 is promoted, so that unevenness in hot water temperature is reduced. Since the convection promoting plate 30 is merely placed, it can be easily taken out, and the convection promoting plate 30 itself or the inside of the tank body 20 can be easily cleaned.
Further, by forming the slit 35 at the lip of the opening 31 on the top surface of the convection promoting plate 30, as shown in FIG. 6, the large bubbles b passing therethrough are crushed and reduced, and temporarily scaled together with the bubbles b. Even if S soars, the amount can be reduced.
In order to place the convection promoting plate 30 on the bottom surface 20A of the tank body 20 in a state where the convection promoting plate 30 is floated to a predetermined size, the legs 37 made of spherical bosses are used and are supported by points, so that crevice corrosion occurs. Is prevented.
[0022]
Second Embodiment
7 and 8 show a second embodiment of the present invention. This second embodiment shows a convection promotion plate 30A with a shape change, and four legs 40 made of spherical bosses are provided at intervals of 90 degrees, of which a pair of diagonally arranged The height of the leg 40A is slightly lower than the height of the other pair of legs 40B.
Since the height of the legs 40A and 40B is changed as described above, the support of the convection promoting plate 30A becomes unstable, so that the convection promoting plate 30A is rotated while being lifted under the influence of convection and bubbles b. The contact position of the legs 40 with respect to the bottom surface 20A of the tank body 20 is frequently changed, so that crevice corrosion is further difficult to occur.
[0023]
<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment, a change is made to the support structure of the convection promoting plate 50.
The structure of the convection promoting plate 50 is the same as that of the convection promoting plate 30 shown in the first embodiment except that the legs 37 on the lower surface of the horizontal portion 33 are removed.
On the other hand, a cover plate 52 with a heat insulating material 53 stretched on the upper surface can be attached to the upper surface opening of the tank body 20, and a hanging metal fitting 55 is provided on the back surface of the cover plate 52. As shown in FIG. 11, the hanging metal fitting 55 has a shape in which a pair of hanging legs 57 are formed at both ends of the base portion 56 by bending an angle member made of stainless steel or the like into a gate shape. A pair of hanging legs 57 are provided in a hanging shape by 56 being fixed to the back surface of the lid plate 52. A mounting plate 58 is formed at the lower end of each suspension leg 57 by bending the lower end portion of one side plate 57A at a right angle.
[0024]
As shown in FIGS. 10 and 11, the mounting plates 58 of the suspension legs 57 of the suspension fitting 55 are applied to two positions spaced apart by 180 degrees on the upper surface of the annular horizontal portion 33 of the convection promoting plate 50. Fastened with fasteners such as welding or rivets.
Then, when the cover plate 52 is put on the upper surface of the tank main body 20, the convection promoting plate 50 is located at the center in the tank main body 20 and the horizontal portion 33 is located at the center of the tank main body 20 as shown in FIG. The bottom surface 20A is suspended and supported by about 3 mm.
[0025]
By arranging the convection promoting plate 50 in this manner, as described in the first embodiment, the scale S deposited on the bottom surface 20A of the tank body 20 is dropped into the drain pipe 25 and smoothly removed. Obtainable.
In addition, the following advantages specific to the third embodiment can be obtained. Since the convection promoting plate 50 is suspended and supported from the lid plate 52 and does not come into contact with the bottom surface 20A of the tank body 20, there is no possibility of erosion corrosion due to crevice corrosion or scratches.
[0026]
The convection promoting plate 50 is not an accessory but is handled integrally with the lid plate 52, and the convection promoting plate 50 is attached and detached automatically as the lid plate 52 is opened and closed, thereby simplifying the operation. For example, by attaching the convection promoting plate 50 with the closure of the lid plate 52, the scale removal function can be exhibited from the beginning of operation rather than from the middle. Further, since the convection promoting plate 50 is removed along with the opening of the lid plate 52, it is very convenient for cleaning.
In addition, the fact that it is not an accessory is less likely to be lost, and packing during transportation can be simplified.
[0027]
Further, since the convection promoting plate 50 is fixed at a fixed position with respect to the cover plate 52, it is always placed at the optimum position as long as the cover plate 52 is normally closed, and the scale excluding function is properly exhibited. Can do. Further, since the convection promoting plate 50 is in a fixed position, the convection generated in the tank main body 20 becomes regular, and the water level detection by the float switch can be performed stably.
Further, due to the self-weight of the convection promoting plate 50 and the hanging metal fitting 55, the sealing performance of the cover plate 52 is increased, the heat retaining property is improved, and it is also effective in suppressing the occurrence of crevice corrosion with the upper edge of the tank body 20. It becomes.
[0028]
<Fourth embodiment>
12 and 13 show a fourth embodiment of the present invention. The fourth embodiment should be called a modification of the third embodiment.
In the fourth embodiment, a pair of slits 60 are formed in the annular horizontal portion 33 of the convection promoting plate 50A by cutting from the outer edge in a posture parallel to each other with an interval of 180 degrees and facing substantially the center.
On the other hand, the hanging metal fitting 55A fixed to the back surface of the cover plate 52 is similarly provided with a pair of hanging legs 62, but the cross-sectional shape of the angle is point-symmetric as shown in FIG. Is formed. And the receiving plate 65 is formed because the lower end of the opposing side plate 63A of the both suspension legs 62 is bent at a right angle.
[0029]
When attaching the convection promoting plate 50A, as shown in FIG. 13, both suspension legs 62 are opened, and the side plate 63B opposite to the side on which each receiving plate 65 is provided is inserted into the slit 60. The back surface of the horizontal portion 33 is received and similarly fastened and fixed by a fastener such as welding or rivet.
When the upper surface of the tank main body 20 is covered with the cover plate 52, the convection promoting plate 50A is also suspended and supported in the center of the tank main body 20 with the horizontal portion 33 floating about 3 mm from the bottom surface 20A of the tank main body 20. Is done.
[0030]
In the fourth embodiment, in addition to obtaining the advantages shown in the third embodiment, the horizontal portion 33 of the convection promoting plate 50A is received by the receiving plate 65 of the suspension leg 62 and then fixed. Therefore, even if the fixing is lost, the convection promoting plate 50A can be prevented from falling on the bottom surface 20A of the tank body 20.
As shown in the third embodiment, the hanging metal fitting is formed by bending one angle member so that the cross-sectional shapes of the angles of both hanging legs are axisymmetric. In this case, the slits 60 formed in the horizontal portion 33 of the convection promoting plate 50A may be arranged on a straight line.
[0031]
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) When the legs are provided on the horizontal part of the convection promoting plate by punching out, the number thereof may be 5 or more. In that case, by changing the height of the legs as in the second embodiment, the crevice corrosion is further reduced. It is also possible to prevent it reliably.
(2) The dimensions of the tank main body and the convection promoting plate shown in the above embodiment are merely examples, and are not limited to the above numerical values.
(3) The present invention is widely applied to all hot water storage tanks in which the supplied water is heated by a heater and stored as hot water, such as a hot water storage tank of a beverage dispenser other than a tea machine. Is possible.
[Brief description of the drawings]
FIG. 1 is a side view showing an internal structure of a tea machine according to a first embodiment of the present invention. FIG. 2 is a plan view showing the inside of a tank body. FIG. 3 is a longitudinal sectional view of the bottom side of the tank body. ] Plan view of convection promoting plate [FIG. 5] Cross-sectional view thereof [FIG. 6] Schematic perspective view showing bubble crushing operation [FIG. 7] Plan view showing inside of tank body according to second embodiment [FIG. FIG. 9 is a longitudinal sectional view showing the inside of the tank body according to the third embodiment. FIG. 10 is a partially cutaway plan view showing a convection promoting plate fixed to a hanging metal fitting. FIG. 12 is a plan view of a convection promoting plate according to a third embodiment. FIG. 13 is a perspective view showing a fixing operation to a hanging metal fitting. FIG. 14 is a schematic perspective view of a comparative example.
DESCRIPTION OF SYMBOLS 10 ... Hot water storage tank 20 ... Tank main body 20A ... Bottom surface 20B (of tank main body 20) ... Inner peripheral surface of (tank main body 20) 23 ... Discharge port 25 ... Drain pipe (drain port)
26 ... Open / close valve 28 ... Heater wire (heater) 29 ... Heater plate 30 ... Convection promoting plate 31 ... Opening 32 ... Conical portion 33 ... Horizontal portion 35 ... Slit (notch)
37 ... Leg b ... Bubble S ... Scale 30A ... Convection promotion plate 40A, 40B ... Leg 50 ... Convection promotion plate 52 ... Lid plate 55 ... Hanging bracket 57 ... Hanging leg 58 ... Mounting plate 50A ... Convection promotion plate 55A ... Suspension Hanging bracket 60 ... Slit 62 ... Hanging leg 65 ... Reception plate

Claims (7)

A drain outlet provided with an opening / closing valve is opened at the center of the bottom surface of the tank body, and a heater is provided around it. Water supplied into the tank body is heated by the heater and stored as hot water, and discharged. In a hot water storage tank that is discharged from the outlet,
A convection promoting plate formed in a frustoconical shape with the top surface serving as an opening on the bottom surface of the tank body positions the opening directly above the drain outlet, and a hem portion from the bottom. A hot water storage tank that is arranged in a floating state.   While the heater is disposed in a circular shape with a predetermined radius, the convection promoting plate has an annular horizontal portion formed at the periphery of the bottom of the conical portion, and the bottom of the conical portion is more radial than the heater. The hot water storage tank according to claim 1, wherein the hot water storage tank is set outside.   The hot water storage tank according to claim 1 or 2, wherein a plurality of notches are formed along a circumferential direction at a lip of the opening in the convection promoting plate.   An annular horizontal portion is formed at the periphery of the bottom of the conical portion in the convection promoting plate, and legs are formed by punching out three or more spherical bosses on the back surface of the horizontal portion. The hot water storage tank according to any one of claims 1 to 3, wherein a hem portion of the convection promoting plate is supported by being floated by a predetermined dimension from the bottom surface by being placed on the bottom surface of the main body. .   The hot water storage tank according to claim 4, wherein four or more of the legs of the convection promoting plate are provided, and a part thereof has a different height.   The lid plate attached to the tank body is provided with a hanging tool, and the hanging tool supports the convection promoting plate in a state where the hem portion is lifted from the bottom surface by a predetermined dimension. The hot water storage tank according to any one of claims 1 to 3, wherein:   The receiving part is provided in the lower end of the said suspending tool, This receiving part is being fixed to this skirt part, receiving the back surface of the skirt part of the said convection promotion board. Hot water storage tank.

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