JPH11346933A - Liquid heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid heating system wherein a sufficient thermal efficiency is provided, the heater itself is miniaturized by preventing the deformation of a liquid tank bottom part and increasing the heat conductivity of a fin itself, and maintenance is easy. SOLUTION: In a liquid heating system 1 for heating liquid in a liquid tank 4 by heating the bottom part 4b of the liquid tank by a burner 5 arranged in the bottom lower part of the liquid tank 4, the liquid tank bottom part 4b is made of a stainless material having a linear expansion coefficient roughly equal to that of copper, and a long fin made of copper is fixed to the backside of the stainless material in a surface contact state. The bottom part 4b of the liquid tank 4 includes a bottom plate unit 6 having, e.g. a stainless plate 7 having a linear expansion coefficient roughly equal to that of copper, and a plurality of copper-made long fins 8 fixed to the backside of the stainless plate 7 in parallel such that an outer peripheral end is positioned in the outer peripheral end of the stainless plate 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid heating device such as a food fryer and a boiler, and more particularly to a liquid heating device capable of efficiently heating a liquid in a liquid tank.

[0002]

2. Description of the Related Art Conventionally, a deep-frying machine as a liquid heating device for frying food with cooking oil stored in an oil tank is disclosed in, for example, Japanese Utility Model Laid-Open No. 61-64837. As shown in FIG. 24, the deep-frying machine 101 has a storage portion 104 that protrudes below the one end of a bottom portion 103 of an oil tank 102 and that stores debris in the oil tank 102, and a burner 105 behind the bottom portion 103. Heat conduction path 106 for conducting heat
Are formed so as to protrude upward, and fins 107 having a cross-shaped cross section are fixed in the heat conduction path 106.

[0003]

However, in the fryer 101, there is a problem that the fins 107 cannot be fixed in close contact with the bottom 103, and sufficient thermal efficiency cannot be obtained. That is, since the fin 107 is formed by joining two long plate members in a cross-shaped cross section and disposing the fin 107 in the concave heat conduction path 106 of the bottom 103, the fin 107 is heated. It is extremely difficult in operation to fix directly to the inner surface of the conduit 106.

[0004] Even if the fins 107 are directly fixed to the inner surface of the heat guide 106, the contact area with the inner surface of the heat guide 106 is only equivalent to the thickness of the two plates, and the surface contact state is not sufficient. In the case of direct fixing, the fins 107 thermally expand and warp in the longitudinal direction,
The bottom 103 of the liquid tank 102 may be deformed. Therefore, the outer peripheral end of the fin 107 must be fixed to the inner surface of the heat conduction path 106 with a predetermined gap.
Therefore, it is difficult to obtain a sufficient heat efficiency because the heat transfer area cannot be set large.

Further, since the fin 107 itself has a complex cross-sectional shape, the cost of parts is increased, and the concave heat conduction path 106 needs to be formed at the bottom 103 of the oil tank 102. There is a problem that the structure of the fryer 101 itself becomes complicated and expensive, such as an increase in the manufacturing cost of the fryer 102.

Further, since the fins 107 having a cross-shaped cross section are fixedly disposed in the heat conduction path 106, the fins 1
07, it becomes difficult to remove soot and the like adhering to the inner part (upper side) in the heat conduction path 106, and cleaning work of the burner 105 becomes very troublesome. There is also a problem that it is difficult to perform this.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fin which can be directly fixed to a bottom portion of a liquid tank in a surface contact state, thereby obtaining a sufficient thermal efficiency. An object of the present invention is to provide a liquid heating device that prevents deformation of a bottom portion of a liquid tank, increases the thermal conductivity of the fin itself, reduces the size of the heating device itself, and facilitates maintenance.
It is another object of the present invention to provide a liquid heating apparatus in which the production of a liquid tank is facilitated and the cost of the heating apparatus itself can be reduced. It is another object of the present invention to provide a liquid heating apparatus capable of preventing deformation of a bottom portion of a liquid tank due to warpage of a fin itself, in addition to the objects of the first or second aspect of the present invention.

The object of the invention described in claim 4 is, in addition to the object of the invention described in claim 3, in addition to the object of the invention, to provide a liquid heating apparatus which can more reliably prevent the deformation of the bottom of the liquid tank due to the warpage of the fin itself. The object of the invention described in claim 5 is, in addition to the object of the invention described in claim 4, a liquid heating device that can more reliably prevent deformation of the bottom of the liquid tank due to warpage of the fin itself. To provide. Claim 6
Another object of the present invention is to provide a liquid heating apparatus capable of uniformly heating the bottom of a liquid tank in addition to the objects of the first to fifth aspects of the present invention. Another object of the present invention is to provide a liquid heating apparatus capable of further improving the thermal efficiency of the bottom of the liquid tank, in addition to the objects of the present invention. The object of the invention of claim 1 is claim 1
Another object of the present invention is to provide a liquid heating apparatus which is easier to maintain, such as being able to store waste generated in a liquid tank in a low-temperature tank.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, the bottom of the liquid tank is heated by a burner disposed below the bottom of the liquid tank, and the liquid in the liquid tank is heated. A liquid heating device for heating a bottom of a liquid tank, wherein the bottom of the liquid tank is formed of a stainless steel having substantially the same linear expansion coefficient as copper, and a long fin made of copper is fixed to a back surface of the stainless steel in a surface contact state. It is characterized by having done.

[0010] With this configuration, the liquid stored in the liquid tank in a predetermined amount is heated by heating the stainless steel material at the bottom of the liquid tank by burning the burner. Flows along the longitudinal direction in a gas passage formed by fins fixed to the back surface of the stainless steel material.
Copper fins with high thermal conductivity are fixed to the back surface of the stainless steel in surface contact, so the heat dissipation (heat transfer) area to the stainless steel increases, and the heat of the combustion gas is efficiently transferred to the stainless steel. Since the fins can be heated and the fins have substantially the same linear expansion coefficient as the stainless steel material, the stainless steel material (bottom portion of the liquid tank), which is the fixing surface of the fins, is prevented from being deformed by heat. In addition, the use of fins having high thermal conductivity allows the fin itself to be formed in a small size, and the bottom of the liquid tank can be formed by directly fixing to the back surface of the stainless steel material. Cleaning becomes easier.

According to a second aspect of the present invention, the bottom of the liquid tank is a stainless steel plate having substantially the same linear expansion coefficient as copper, and the outer peripheral edge of the stainless steel plate is located at the outer peripheral edge of the stainless steel plate. It is characterized by having a bottom plate unit comprising a plurality of long fins made of copper fixed and juxtaposed as described above.
With this configuration, the liquid tank can be manufactured by simply fixing the fins to the stainless steel plate in advance and forming the bottom plate unit, and then fixing the bottom plate unit to the bottom of the liquid tank, thereby facilitating the manufacturing of the liquid tank.

Further, according to a third aspect of the present invention, the fin comprises:
It is characterized by having a thermal expansion absorbing means capable of absorbing thermal expansion. With such a configuration, when the fins are heated by, for example, the combustion gas of the burner, the thermal expansion is absorbed by the thermal expansion absorbing means provided on the fins, and the fins are warped or the fins are warped. Deformation of the tank bottom is prevented.

According to a fourth aspect of the present invention, the fin has a fixed wall portion and a side wall portion protruding from the fixed wall portion, and the thermal expansion absorbing means is a slit formed along the direction in which the side wall portion protrudes. There is a feature. With such a configuration, the thermal expansion of the fin due to the combustion gas or the like is absorbed by the slit as the thermal expansion absorbing means, and at this time, the slit is formed along the projecting direction of the side wall of the fin. This slit reliably absorbs the thermal expansion in the longitudinal direction of the fin.

The invention according to claim 5 is characterized in that the deepest position of the slit reaches the fixed wall.
With this configuration, the side walls of the fins are completely separated in the longitudinal direction by the slits, and the thermal expansion is more reliably absorbed by each slit.

Further, the invention according to claim 6 is characterized in that the shape of the fin is set according to the temperature gradient of the combustion gas of the burner. With such a configuration, the fin heated by the combustion gas of the burner has, for example, a lower height of the side wall having a higher temperature on the burner side and a higher height of the side wall on the opposite side of the burner having a lower temperature, that is, The height (shape) of the fin in the longitudinal direction is set according to the temperature gradient of the combustion gas, and the heating condition of the bottom of the liquid tank by the fin is made uniform.

The invention according to claim 7 is characterized in that the bottom portion of the liquid tank is inclined at least along the longitudinal direction of the fins on the side where the burners are arranged. With this configuration, a draft effect of flowing the combustion gas along the longitudinal direction of the fins at the inclined portion at the bottom of the liquid tank is obtained, and the thermal efficiency of the liquid tank is further increased.

The invention according to claim 8 is characterized in that the bottom of the liquid tank has a low-temperature tank at a position not directly receiving the heat of the burner. With this configuration,
For example, dregs generated in the liquid tank can be accommodated in the low-temperature tank, which facilitates cleaning of the liquid tank and prevents contamination of the liquid used in the liquid tank.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 7 show a first embodiment of a liquid heating apparatus according to the present invention. FIG. 1 is a plan view thereof, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 4 is a partially cutaway perspective view of the bottom plate unit, FIG. 5 is an enlarged view of a portion C of FIG. 2, FIG. 6 is a partially cutaway side view of the fin, and FIG. It is explanatory drawing of the fixing method.

1 to 3, a liquid heating device 1 comprises:
A leg 3 is provided at a lower portion, and has a substantially rectangular parallelepiped housing 2 formed of, for example, a stainless steel plate.
And a gas burner 5 is arranged at a lower part on the front side (lower side in FIG. 1) of the liquid tank 4. The liquid tank 4 is formed in a substantially rectangular parallelepiped shape having an opening 4a on the upper surface, and a bottom plate unit 6 forming a heating surface is integrally disposed on a bottom 4b.

As shown in FIG. 4, the bottom plate unit 6 has a stainless plate 7 having substantially the same size as the bottom portion 4b of the liquid tank 4, and a fixed interval on the back surface of the stainless plate 7. A plurality of (eight in the figure) long fins 8 are fixed. The stainless steel plate 7 has, for example, 18Cr. 8N
i made of stainless steel.

On the other hand, the fins 8 are formed into a U-shaped cross section by bending a copper plate made of pure copper, and are formed at both ends of the fixed wall portion 8a serving as a fixing surface to the stainless steel plate 7 and both ends of the fixed wall portion 8a. It has a pair of side walls 8b. A gas passage 9a is formed in each fin 8 by the pair of side walls 8b of each fin 8, and a gas passage 9b is formed between the fins 8 by a pair of side walls 8b of the adjacent fins 8. The widths of the gas passages 9a and 9b are set to, for example, w1 = 12 mm and w2 = 4 mm, as shown in FIG. 5, but are not limited thereto. The setting can be changed as appropriate in accordance with the combustion amount or the like.

As shown in FIG. 6, the fins 8 are formed with a plurality of slits 10 for forming thermal expansion absorbing means at fixed intervals (or gradually narrowing or widening) in the longitudinal direction of the pair of side walls 8b. Have been. This slit 1
0 has a predetermined width w1 and is provided along the projecting direction of the side wall portion 8b, and its deepest portion reaches the fixed wall portion 8a, whereby the fins 8 are connected in the longitudinal direction by the fixed wall portion 8a. However, the side wall portions 8b are completely separated in the longitudinal direction by the slits 10.

The fins 8 are provided on the stainless steel plate 7.
4 is fixed in a state of juxtaposition at a predetermined interval on one surface (back surface) of the stainless steel plate 7, as shown in FIG. It is fixed to the outer peripheral edge 7a with a predetermined allowance L. The fins 8 are fixed to the stainless steel plate 7 by, for example, placing the fins 8 side by side with the back surface of the stainless steel plate 7 facing up as shown in FIG. At the same time, the fixing plate 20 is welded to each of the fins 8 of the stainless steel plate 7 at the L end portions at both ends in the longitudinal direction.

At this time, the fixing plate 20 is provided with projections 20a corresponding to the fins 8, and the projections 20a are welded in a state of being fitted between the side walls 8b at both ends in the longitudinal direction of the fins 8. I do. As a result, each fin 8 is fixed to the fixed plate 20.
Are positioned on the stainless steel plate 7 and the stainless steel plate 7 on which the fins 8 are positioned is supplied to an in-furnace brazing machine (not shown).
And the back surface of the stainless steel plate 7 are brazed and fixed with a copper braze or the like.

The method of fixing the fins 8 to the stainless steel plate 7 is not limited to the above-described brazing in a furnace, and it is needless to say that other appropriate fixing methods such as ultrasonic metal welding and high frequency welding can be adopted. It is possible. Further, at the time of manufacturing the bottom plate unit 6, the allowance L of the outer peripheral edge portion 7a of the stainless steel plate 7 is preferably set to be smaller from the relation of warpage due to heat at the time of brazing in a furnace. Alternatively, the bottom plate unit 6 may be bent in a predetermined direction to prevent warping of the bottom plate unit 6, or may be bent after brazing to correct the warpage of the bottom plate unit 6.

In the bottom plate unit 6 thus manufactured, the outer peripheral edge 7a of the stainless steel plate 7 is fixed to the lower end of the peripheral wall 4c of the liquid tank 4 by argon welding or the like as shown in FIG. ing. That is, the liquid tank 4 forms, for example, a peripheral wall member having a rectangular cross section with an open top and bottom,
It is manufactured by welding and fixing the bottom plate unit 6 manufactured in advance to the lower end opening of the peripheral wall member.

The gas burner 5 disposed below the liquid tank 4 is formed of a Bunsen gas burner. As shown in FIG. 3, the head has a large number of flame ports and a gas valve 13 connected thereto. The gas burner 5 is connected to the liquid tank 4
The bottom plate unit 6 is disposed so as to be located below the front side, and the installation interval between the front end of the flame and the back surface of the stainless plate 7 of the bottom plate unit 6 is set to be about 100 mm, for example.

A shielding plate 14 made of, for example, an L-shaped stainless steel plate is provided at a predetermined distance from the bottom plate unit 6 behind the gas burner 5 of the housing 2. The rear end is fixed to the bottom wall 2 a of the housing 2, and the rear end is fixed to the rear wall 2 b of the housing 2. This shielding plate 1
4 and the bottom plate unit 6 of the liquid tank 4
A combustion gas passage 15 including a and 9b is formed, and an exhaust duct 16 is connected to a downstream side 15b of the combustion gas passage 15.

The upper end of the exhaust duct 16 has the liquid tank 4.
Are provided so as to protrude above the upper surface of the upper surface, and a large number of exhaust holes 17 are formed in the upper end surface. Further, the housing 2 is provided with a drain valve 19 for draining the liquid W in the liquid tank 4 from a drain hole (not shown) provided at an appropriate position of the bottom 4b (bottom plate unit 6). I have.

Next, the operation of the liquid heating apparatus 1 will be described with reference to FIG. First, a predetermined amount of liquid W such as water or edible oil is stored in the liquid tank 4, a set temperature or the like is set by an operation panel (not shown), and the gas valve 13 is opened to burn the gas burner 5. When the gas burner 5 burns, the flame is discharged upward, and the combustion gas generated by the flame flows from the upstream side 15a to the downstream side 15b in the combustion gas passage 15 communicating with the outside air via the exhaust duct 16. Flows. The combustion gas is mostly supplied to a gas passage 9 formed by each fin 8.
a and 9b flow as shown by arrows a and b in FIGS. 1 and 3, and a part of the gas flows 9a and 9 as shown by arrow c in FIG.
It flows inside the combustion gas passage 15 outside b.

The combustion gas flowing in the fin 8 is
The gas flows through the gas passages 9a and 9b while being in contact with the fixed wall portion 8a of the fin 8 and the inner surface of the side wall portion 8b on both sides of the fixed fin portion 8a.
Temperature is increased. At this time, since the fixed wall portion 8a of the fin 8 having a U-shaped cross section is directly fixed to the back surface of the stainless steel plate 7 in a surface contact state, three surfaces including the fixed wall portion 8a of the fin 8 and a pair of side wall portions 8b are provided. Directly receive the heat of the combustion gas flowing in the gas passages 9a and 9b and radiate (heat transfer) the heat from the fixed wall portion 8a which is fixed to the stainless steel plate 7 in surface contact and forms a large heat dissipation surface. become.

Further, since the fins 8 are formed of a copper plate, the heat conductivity can be increased to 23 times or more as compared with the case where the fins 8 are formed of a stainless steel plate 7, and the heat of the combustion gas can be increased. Is the stainless plate 7 of the bottom plate unit 6
Heat is transferred quickly. Thereby, the bottom plate unit 6
The temperature of the stainless steel plate 7 is efficiently increased and the liquid tank 4
While the convection is being generated in the liquid W inside, the temperature of the liquid W is raised to a predetermined temperature.

When the gas burner 5 burns for a predetermined time and the fin 8 is heated to a predetermined temperature by the combustion gas flowing through the combustion gas passage 15 including the gas passages 9a and 9b, the fin 8 itself thermally expands. A force acts to warp in the longitudinal direction. However, the force acting on the fin 8 is absorbed by the slit 10 provided in the side wall portion 8b of the fin 8, and the fin 8 is prevented from warping. At this time, since the slit 10 of the fin 8 opens at the tip of the pair of side wall portions 8b in the protruding direction and is formed so that the deepest position reaches the fixed wall portion 8a, the pair of side wall portions 8b extend in the longitudinal direction. In this case, the slits 10 are completely separated, and the thermal expansion of the side wall 8b due to heat is reliably absorbed by the slits 10.

The absorption of the thermal expansion by the slits 10 of the fins 8 prevents the side walls 8b from warping,
The effect of stress due to thermal expansion on the fixed wall portion 8a due to the warpage of the side wall portion 8b, that is, the effect of stress on the stainless steel plate 7 of the bottom plate unit 6 is suppressed. And the gas passage 9
The combustion gas flowing through the combustion gas passage 15 including the exhaust holes 1a and 9b flows through the exhaust duct 16 as indicated by the arrow d.
From 7, it is exhausted to the outside as exhaust gas as indicated by arrow E.

As described above, in the liquid heating apparatus 1 of the first embodiment, a plurality of fins 8 having a U-shaped cross section are arranged in parallel along the longitudinal direction on the back side of the bottom 4b of the liquid tank 4. Since it is fixed in a state, the combustion gas generated by the combustion of the gas burner 5 can flow into the gas passages 9a and 9b formed by the fins 8, and the fins 8 are formed of a copper plate having a high thermal conductivity. Therefore, the heat transfer efficiency of the fins 8 itself can be increased, and the heat of the combustion gas can be efficiently transferred to the stainless steel plate 7 of the bottom plate unit 6.

In particular, the fin 8 is formed in a U-shaped cross section,
Since the planar fixed wall portion 8a is fixed to the back surface of the stainless steel plate 7 of the bottom plate unit 6 in a surface contact state by brazing, heat is radiated from the fins 8 to the stainless steel plate 7 by the fixed wall portion 8a (heat transfer). ) The area can be increased (for example, 100 times or more as compared with the case where the plate-like fins are erected vertically). When the heat dissipating area is increased, the plate-shaped fins, which are likely to be generated when the above-described plate-shaped fins are erected in a vertical state on the back surface of the stainless steel plate 7, also eliminate the red heat of the fins themselves. Is further improved, and a decrease in the durability of the fins 8 due to red heat is also prevented. From these, the liquid tank 4
The liquid W inside can be heated to a predetermined temperature in a very short time. For example, if the liquid heating device 1 is used as a food fryer, efficient frying work can be performed.

Further, since a copper plate having a high thermal conductivity is used as the fin 8, the height h (see FIG. 6) of the side wall portion 8b is made lower than that of a conventional fin made of stainless steel or the like. Therefore, the size of the liquid heating device 1 itself can be reduced, for example, the size of the bottom plate unit 6 can be reduced, and the width w2 (see FIG. 2) of the combustion gas passage 15 can be reduced along with the reduction in the size of the fins 8. Can be formed.

Further, since the fin 8 has a U-shaped cross section and the fixed wall portion 8a is fixed to the back surface of the stainless steel plate 7 of the bottom plate unit 6, the shape of the fin 8 itself is simplified and the liquid tank is formed. It is no longer necessary to form a concave heat conduction path on the bottom 4b of the base 4 as in the prior art, and the configuration of the fins 8, the liquid tank 4, and the like can be simplified.

Also, the liquid tank 4 can be manufactured by welding and fixing the bottom plate unit 6 in which the fins 8 are previously brazed in the furnace to the stainless steel plate 7 in the lower end opening of the peripheral wall 4c. The liquid tank 4 can be easily manufactured, for example, by automatically performing the fixing operation of the liquid tank 4. Accordingly, the manufacturing cost of the bottom plate unit 6 and the liquid heating device 1 itself can be reduced, and the cost of the liquid heating device 1 can be reduced by downsizing the heating device 1 itself.

Further, since the fins 8 have a U-shape, the rigidity of the fins 8 can be increased, and the durability of the fins 8 themselves can be improved, for example, the fins 8 do not glow as described above. Can be. Further, since the fins 8 have substantially the same linear expansion coefficient as the stainless steel plate 7, thermal deformation at the joint between the fins 8 and the stainless steel plate 7 can be suppressed, and the pair of side walls 8 b of the fins 8 have the deepest portions. Since the slits 10 reaching the fixed wall portions 8a are formed, the side wall portions 8b of the fins 8 can be completely separated by the slits 10 in the longitudinal direction, and the thermal expansion of the fins 8 can be reliably performed by the slits 10. Can be absorbed.

From these facts, the deformation of the bottom plate unit 6 due to heat when the fins 8 are fixed to the stainless steel plate 7 is prevented, and the fins 8 themselves warp when the gas burner 5 burns, and the fins 8 warp. The deformation of the stainless plate 7, that is, the deformation of the bottom 4b of the liquid tank 4 can be reliably prevented.

The fin 8 has a U-shaped cross section and a side wall 8b.
Since the space is opened downward, soot and the like adhering to the inside of the fins 8 can be easily removed with, for example, a brush, and the back surface of the bottom 4b and the gas burner 5 can be easily cleaned. In particular, by removing the shielding plate 14 provided below the bottom plate unit 6 of the liquid tank 4, the back side of the bottom plate unit 6 can be exposed, and the fins 8 can be exposed.
Can be performed more easily, and maintenance of the liquid heating apparatus 1 can be performed extremely easily.

FIGS. 8 to 10 are sectional views showing the main parts of another embodiment of the liquid tank of the liquid heating apparatus according to the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The same applies to the following embodiments. First, in the liquid tank 4 of the second embodiment shown in FIG. 8, the bottom plate unit 6 is inclined and welded and fixed to the peripheral wall 4c of the liquid tank 4 so that the gas burner 5 side is low and the exhaust duct 16 side is high. .

In the liquid tank 4 of the second embodiment, the same operation and effect as those of the first embodiment can be obtained. In addition, since the bottom 4b of the liquid tank 4 is inclined, a draft effect of the combustion gas is obtained. And the flow state of the combustion gas flowing in the combustion gas passage 15 is improved, and the operational effect that the thermal efficiency can be further improved can be obtained.

The liquid tank 4 of the third embodiment shown in FIG.
The length of the fins 8 of the bottom plate unit 6 of the liquid tank 4 of the first embodiment is shortened, and the bottom plate unit 6 is placed above the gas burner 5.
Front portion 7 of stainless steel plate 7 to which no fin 8 is fixed
b are directly opposed to each other. In the liquid tank 4 of the third embodiment, the same operation and effect as those of the first embodiment can be obtained.

The liquid tank 4 of the fourth embodiment shown in FIG.
Is such that an inclined surface 21 is provided on a front portion 7b of the bottom plate unit 6 where the fins 8 on the gas burner 5 side are not fixed. Also in the liquid tank 4 of the fourth embodiment, a draft effect of the combustion gas is obtained on the inclined surface 21, and the same operation and effect as in the second embodiment can be obtained. The third
In the fourth embodiment, only the portion of the stainless steel plate 7 to which the fins 8 are fixed is used as the bottom plate unit 6, and another stainless steel plate forming the front portion 7b is fixed to the stainless steel plate 7 of the bottom plate unit 6 by welding. By the bottom 4b
Can also be formed.

FIGS. 11 to 16 show the fifth to eighth embodiments of the liquid tank of the liquid heating apparatus according to the present invention. Low temperature bath 22
Is provided. First, the fifth line shown in FIG.
In the liquid tank 4 of the embodiment, the end of the bottom 4b on the side of the gas burner 5 is recessed downward, and this recess is used as a low-temperature tank 22 that does not directly receive the heat of the gas burner 5. Then, for example, the bottom plate unit 6 is fixedly arranged on the upper edge of the low-temperature tank 22, and the drain valve 19 (not shown) is provided on the bottom surface 22 a of the low-temperature tank 22.
Are connected.

According to the liquid tank 4 of the fifth embodiment, in addition to the functions and effects of the first embodiment, the low-temperature tank 22 is provided along the left-right direction of the front end of the liquid tank 4 as follows. Various operational effects can be obtained. That is, the waste generated in the liquid tank 4 can be settled (stored) in the low-temperature tank 22 in which the stored liquid W does not boil or the like. And the drainage valve 19 is opened, the drainage can be drained and removed downward, and the cleaning of the liquid tank 4 can be easily performed. Also,
Since the waste material has settled in the low-temperature tank 22, the waste material does not convect in the liquid tank 4, and the contamination of the liquid W in the liquid tank 4 can be prevented.

The liquid tank 4 of the sixth embodiment shown in FIG.
Is provided with a low-temperature tank 22 that is recessed downward along the front-rear direction at substantially the center of the bottom 4b in the left-right direction, and the gas burners 5 are arranged on both sides of the low-temperature tank 22, respectively. In the liquid tank 4, for example, a pair of bottom plate units 6 having the same shape is manufactured, and the bottom 4 b is formed in a state where the low-temperature tank 22 is provided between the bottom plate units 6. In the liquid tank 4 of the sixth embodiment, the same operation and effect as those of the fifth embodiment can be obtained.

The liquid tank 4 of the seventh embodiment shown in FIGS. 13 and 14 is provided with low-temperature tanks 22 along both front and rear ends of the bottom 4b in the left-right direction. The gas burner 5 is arranged. In the liquid tank 4 of the seventh embodiment, the same operation and effect as those of the fifth embodiment can be obtained.

Further, in the liquid tank 4 of the eighth embodiment shown in FIGS. 15 and 16, a low-temperature tank 22 having a substantially U-shape in plan view is provided at the front end of the bottom 4b and at both ends in the left-right direction. An air layer 23 is provided below the shielding plate 14 and in the exhaust duct 16. The air layer 23 is formed, for example, by vertically extending the rear end of the shielding plate 14 into the exhaust duct 16 and at a predetermined interval below the shielding plate 14.
4 is formed.

According to the liquid tank 4 of the eighth embodiment, the same operation and effect as those of the fifth embodiment can be obtained.
Can be blocked by the low-temperature air in the air layer portion 23, so that the temperature rise of the outer wall 2b and the like of the housing 2 can be suppressed, and it is particularly suitable for use as a fryer or the like. The effect is obtained. The air layer portion 23 is not limited to the eighth embodiment, but can be applied to the liquid tank 4 of the first to seventh embodiments.

The embodiments of the liquid tank 4 have been described above. Next, the embodiments of the fins 8 that can be used in these liquid tanks 4 will be described with reference to FIGS. The fins 8 of each embodiment are formed of the same copper plate as the fins 8 of the first embodiment. First, the fin 8 shown in FIG. 17 is formed in a U-shaped cross section similarly to the fin 8 of the first embodiment, and the height h of the pair of side wall portions 8b is made different at both ends in the longitudinal direction. It was done. That is, the height h1 of the fin 8 on the gas burner 5 side is set to be continuously smaller than the height h2 on the side opposite to the gas burner 5. Therefore, the depth of the slit 10 also gradually increases toward the gas burner 5 side.

According to the fin 8 of this embodiment, the fin 8
The heat transfer area of the fins 8 is set along the temperature gradient of the combustion gas in the gas passages 9a and 9b formed by the gas, in which the temperature on the gas burner 5 side is high and the temperature on the anti-gas burner 5 side is low. Side heat transfer area). Therefore, the efficiency of heat transfer to the stainless steel plate 7 in the longitudinal direction of the fins 8 can be averaged, and as a result, the effect of uniformly heating the bottom 4b of the liquid tank 4 can be obtained.

In the fin 8 of this embodiment,
The heights h1 and h2 at both ends in the longitudinal direction are not limited to change linearly from one end to the other end, but may be configured to change in an arc shape or in a stepwise manner. The thickness of the fins 8 may be changed along the length of the fins 8, that is, the fins 8 include all shapes in which the heat transfer areas at both ends in the longitudinal direction are different according to the temperature gradient.

The fins 8 shown in FIG. 18 are formed such that the fins 8 having a U-shaped cross section are tapered along the direction in which the side wall portions 8b protrude, and the fixing wall portions 8a of the fins 8 are arranged side by side. It is fixed to the stainless steel plate 7 in close contact. Accordingly, the gas passages 9a are formed in the fins 8, and the gas passages 9b are formed between the side walls 8b of the fins 8 adjacent to each other.

According to the fins 8 of this embodiment, the number of side walls 8b of the fins 8 fixed to the stainless steel plate 7 is larger than that of the fins 8 of the first embodiment, and the heat transfer area is wider. As a result, the operational effect that the thermal efficiency can be further improved can be obtained.

The fin 8 shown in FIG. 19 is formed in an L-shaped cross section having a fixed wall portion 8a and one side wall portion 8b erected on one end side of the fixed wall portion 8a. In this state, the wall portions 8a are fixed to the stainless steel plate 7 of the bottom plate unit 6 in a state of being closely attached in the juxtaposed direction. In the fin 8 of this embodiment, the gas passage 9a is not formed in the fin 8 itself, but the gas passage 9b is formed between the adjacent fins 8, and the same operation and effect as the fin 8 of the first embodiment can be obtained. In addition to the above, there is an operational effect that the shape of the fin 8 itself is simplified and the fin 8 can be formed at lower cost.

The fin 8 shown in FIG.
Is formed in a U-shaped cross section, and a projection 26 is provided on the outer surface of at least one of the side wall portions 8b.
a is fixed to the stainless steel plate 7.
According to the fin 8 of this embodiment, since the predetermined gap k is formed between the side walls 8b of the adjacent fins 8 by the projections 26, the side walls 8b due to the surface tension of the brazing material at the time of brazing in the furnace. Between the fins 8
The operation and effect that the interval setting work as shown in FIG. 17 and the shape correction of the fins 8 after the fixing can be easily performed can be obtained.

Further, as the fin 8 shown in FIG. 21, an integrated fin 8 provided with alternately U-shaped sections 27 is used, and one fixed wall portion 27a of the fin 8 is fixed to the stainless steel plate 7. Things. In the fin 8 of this embodiment, in addition to obtaining the same operation and effect as the fin 8 of the first embodiment, since the fin 8 is of an integral type, for example, when brazing to the stainless plate 7 in a furnace, The setting work on the stainless steel plate 7 can be easily performed, and the fixing plate 2
The effect of being able to simplify the configuration such as 0 is obtained.

The fin 8 shown in FIG.
Is formed in a T-shaped cross section having a fixed wall portion 8a and a side wall portion 8b, and the fixed wall portion 8a of the fin 8 is fixed to the stainless steel plate 7. Also in the fin 8 of this embodiment,
The fixed wall portion 8a can be fixed to the stainless steel plate 7 in a surface contact state, and the same operation and effect as the fin 8 of the first embodiment can be obtained.

The fin 8 shown in FIG.
The slit 10b is formed such that its deepest position does not reach the fixed wall portion 8a. That is, the fin 8
The depth h3 of the slit 10 is set so as to have a certain dimension h4 between the deepest position of the slit 10 and the fixed wall portion 8a. Also in the fin 8 of this embodiment, the slit 10
As compared with the first embodiment in which the deepest position of the fin 8 reaches the fixed wall portion 8a, although the absorption rate at the time of thermal expansion is slightly inferior, each slit 10 absorbs the thermal expansion of the fin 8 in the longitudinal direction and warps. Etc. can be prevented.
The same operation and effect as the embodiment can be obtained. In the case of the fins 8 of this embodiment, as shown by the two-dot chain line, the fins 8 having different heights at both ends in the longitudinal direction can be similarly configured.

The structure of the liquid tank and the fins of the liquid heating apparatus according to the present invention is not limited to each of the above-described embodiments. For example, the liquid tanks of the first to eighth embodiments may have various structures. The embodiments can be appropriately combined, such as using each of the fins alone or a plurality of types at the same time. Further, in each of the above embodiments, the case where the liquid tank is formed by welding and fixing the bottom plate unit in which the fin is fixed to the stainless steel plate in advance to the lower portion of the peripheral wall of the liquid tank has been described, but the present invention is not limited to this. Instead, for example, a structure in which a liquid tank having a bottom surface is formed in advance and fins are fixed to the back side of the bottom surface of the liquid tank to form a bottom portion may be used.

Further, in each of the above embodiments, the liquid tank is formed in a rectangular shape in plan view, but may be formed in a square shape. In each of the above embodiments, the structure of the liquid tank, the number of fins,
The length and juxtaposition, the installation area and position of the bottom plate unit with respect to the bottom of the liquid tank, the welding structure, the relationship between the thickness of the stainless plate and the fin, etc. are also examples, and various changes are made without departing from the gist of each invention. It goes without saying that it is possible.

[0065]

As described in detail above, according to the first aspect of the present invention, the fins are formed of copper having a high thermal conductivity and the back surface of the stainless steel material having substantially the same linear expansion coefficient as copper. Since the fins are fixed in surface contact with each other, the radiating area of the fins to the stainless steel material is increased, and the heat of the combustion gas can be efficiently transferred to the stainless steel material.
The thermal efficiency of the liquid tank can be increased, and the fin has substantially the same linear expansion coefficient as the stainless steel material, so that the deformation of the bottom of the liquid tank due to heat can be prevented. In addition, since the fins are made of copper and have high thermal conductivity, the fins themselves and the heating device can be formed in a small size, and the liquid tank bottom can be formed by simply fixing the fin fixing surface directly to the stainless steel back surface. The shape of the liquid tank is simplified, and maintenance can be easily performed.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, a fin is fixed to a stainless steel plate to form a bottom plate unit in advance, and this is simply fixed to the bottom of the liquid tank. Therefore, the liquid tank can be manufactured easily, and the cost of the liquid heating device can be reduced.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect, even when the fin is heated by the combustion gas of the burner or the like, the thermal expansion absorption provided in the fin is provided. Because the thermal expansion is absorbed by the means,
Deformation of the bottom of the liquid tank due to warping of the fins and the like can be prevented.

According to the fourth aspect of the invention, in addition to the effect of the third aspect, the slit as the thermal expansion absorbing means is formed along the direction in which the side wall of the fin projects. Thermal expansion in the longitudinal direction of the fin is absorbed by each slit, and deformation of the bottom of the liquid tank due to warping of the fin or the like can be reliably prevented.

According to the fifth aspect of the invention, in addition to the effect of the fourth aspect, since the deepest position of the slit in the projection direction of the side wall portion of the fin reaches the fixed wall portion, The longitudinal direction of the side wall portion is completely divided by the slits, and the thermal expansion is reliably absorbed by each slit, so that the deformation of the bottom of the liquid tank due to warping of the fins or the like can be more reliably prevented. .

According to the sixth aspect of the invention, in addition to the effects of the first to fifth aspects, the longitudinal shape of the fin can be set according to the temperature gradient of the combustion gas of the burner. Therefore, the heating conditions of the entire heating surface of the bottom of the liquid tank by the fins during burner combustion can be averaged, and the bottom of the liquid tank can be uniformly heated.

According to the seventh aspect of the present invention, in addition to the effects of the first to sixth aspects, a draft effect is obtained for the combustion gas of the burner by the inclined portion provided in the longitudinal direction of the fin, and The thermal efficiency at the bottom of the tank can be further increased.

According to the eighth aspect of the present invention, in addition to the effects of the first to seventh aspects, the waste generated in the liquid tank can be accommodated in the low-temperature tank. The cleaning of the bottom can be simplified and the liquid used can be prevented from being stained. For example, maintenance of the liquid heating device can be performed more easily.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of a liquid heating apparatus according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a partially cutaway perspective view of the bottom plate unit.

FIG. 5 is an enlarged view of a portion C in FIG. 2;

FIG. 6 is a partially cutaway side view of the fin.

FIG. 7 is an explanatory view of a fixing method of the fin.

FIG. 8 is a sectional view of a main part of a liquid tank showing a second embodiment of the liquid heating apparatus according to the present invention.

FIG. 9 is a sectional view of a main part of a liquid tank showing a third embodiment of the liquid heating apparatus according to the present invention.

FIG. 10 is a sectional view of a main part of a liquid tank showing a fourth embodiment of the liquid heating apparatus according to the present invention.

FIG. 11 is a sectional view of a main part of a liquid tank showing a fifth embodiment of the liquid heating apparatus according to the present invention.

FIG. 12 is a sectional view of a main part of a liquid tank showing a sixth embodiment of the liquid heating apparatus according to the present invention.

FIG. 13 is a sectional view of a main part of a liquid tank showing a seventh embodiment of the liquid heating apparatus according to the present invention.

FIG. 14 is a schematic sectional view taken on line DD of FIG. 13;

FIG. 15 is a sectional view of a main part of a liquid tank showing an eighth embodiment of the liquid heating apparatus according to the present invention.

FIG. 16 is a schematic sectional view taken along line EE in FIG. 15;

FIG. 17 is a side view showing another embodiment of the fin used in the liquid heating apparatus according to the present invention.

FIG. 18 is a sectional view showing still another embodiment of the fin.

FIG. 19 is a sectional view showing still another embodiment of the fin.

FIG. 20 is a sectional view showing still another embodiment of the fin.

FIG. 21 is a sectional view showing still another embodiment of the fin.

FIG. 22 is a sectional view showing still another embodiment of the fin.

FIG. 23 is a partially cutaway side view showing still another embodiment of the fin.

FIG. 24 is a schematic side view of a conventional liquid heating device.

[Explanation of symbols]

 1 ... Liquid heating device 4 ... Liquid tank 4a ... Opening 4b ... Bottom 4c ... Peripheral wall 5 ... ··· Gas burner 6 ···· Bottom plate unit 7 ···· Stainless steel plate 7a ··· Outer peripheral edge 8 ····· Fin 8a ··· · Fixed wall 8b ··· Side wall 9a, 9b ··· Gas passage 10 ··· Slit 14 ··· Shield plate 15 ··· Combustion gas passage 16 · ····· Exhaust duct 21 ·························································· Liquid

Claims (8)

[Claims] 1. A liquid heating apparatus for heating a liquid in a liquid tank by heating the liquid tank bottom with a burner disposed below the liquid tank bottom, wherein the liquid tank bottom has substantially the same linear expansion coefficient as copper. A liquid heating device comprising: a stainless steel material having the following formula: and a long copper fin fixed to the back surface of the stainless steel material in a surface contact state. 2. A stainless steel plate having substantially the same linear expansion coefficient as copper, and a copper bottom fixed to the rear surface of the stainless steel plate so that an outer peripheral end is located at an outer peripheral edge of the stainless steel plate. The liquid heating apparatus according to claim 1, further comprising a bottom plate unit including a plurality of long fins. 3. A liquid heating apparatus according to claim 1, wherein said fin has a thermal expansion absorbing means capable of absorbing thermal expansion. 4. The fin has a fixed wall portion and a side wall portion projecting from the fixed wall portion, and the thermal expansion absorbing means is a slit formed along a direction in which the side wall portion protrudes. The liquid heating device according to claim 3. 5. The liquid heating apparatus according to claim 4, wherein the deepest position of the slit reaches the fixed wall. 6. The liquid heating apparatus according to claim 1, wherein the shape of the fin is set in accordance with a temperature gradient of a combustion gas of a burner. 7. The liquid heating apparatus according to claim 1, wherein the bottom of the liquid tank has at least a side on which the burner is disposed inclined along a longitudinal direction of the fin. 8. The liquid heating apparatus according to claim 1, wherein said liquid tank bottom has a low-temperature tank at a position not directly receiving heat from said burner.