JP2011133141A - Heating pipe and cooking machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating pipe having a simple structure, being easily manufactured at low costs, having high heating efficiency and durability to be used for a long time, and capable of performing a continuous operation at low costs. <P>SOLUTION: This heating pipe is a double pipe configured by inserting an inner pipe composed of copper or copper alloy into an outer pipe composed of a steel or stainless pipe, the adhesion or pressure-bonding of the double pipe is performed with pipe inner pressure or pipe outer pressure, and the adhesion and pressure-bonding are fixed by forming a bulging section to inner and outer sides through the inner pipe and the outer pipe. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heating tube and a cooking device using the heating tube, and more specifically to a cooking device such as a fryer and boiled noodles, and a heating tube useful for them.

As a heating device, a combustion gas generated by a combustion burner such as gas and oil is supplied to an exhaust pipe and a heating pipe disposed in a storage tank, and fluid such as water and oil is supplied through the heating pipe by the exhaust heat. There are a method of heating the steam or a method of contributing to steam generation as a boiler smoke pipe.
In order to increase the thermal efficiency of the heating tube, an apparatus has been proposed in which various fins are installed on the heating tube to improve the thermal efficiency.

  It is used as a cooking utensil as a heating tube for a fryer, boiled noodle machine or other equipment, configured as a device that stores water, oil, etc. in the tank and heats the exhaust pipe installed in the tank. ing.

JP-T-2006-527660 JP 2007-296554 A JP 2001-62522 A JP 2000-157425 A Japanese Utility Model Publication No. 60-52152

  Here, the heating pipe refers to a device for passing the combustion gas and heating the fluid in contact with the exhaust pipe, and is used in the same manner as the piping and the exhaust heat pipe.

As a double-walled metal tube, a reference 1 proposes a double-walled metal tube having a brazing layer between metal layers of a tubular roll-formed metal strip, the brazing layer being made of a copper alloy. Yes.
Since this structure forms a double tube with a brazing layer, it is difficult to obtain the strength of the brazing layer, and it is difficult to manufacture and cost.

  Further, Patent Document 2 proposes a method of manufacturing a double pipe in which an inner pipe is inserted into an outer pipe and press-molded from above the outer pipe. This is a so-called pressing method using a pressing device, and the deformation mode for pressurization of the outer tube and the inner tube is different, and the outer tube can be reduced without reducing the outer tube excessively. That's it.

  However, as described in the specification, it is better to increase the yield stress of the inner tube. In this manufacturing method, it is a so-called diameter reduction process, and the circular steel pipe is made into a square steel pipe corresponding to the V-shaped upper and lower cross-sectional shapes, and then the V-shape is corrected by the second molding, and the corner portion is changed. It is necessary to go through a number of steps to make it smaller, and the manufacture thereof is not easy and the cost increases.

In addition, this method has different deformation modes due to pressure molding due to the difference in yield stress between the outer tube and the inner tube, and the outer tube and the inner tube can be brought into strong contact with each other. It can be explained that it is not necessary to shrink excessively, the diameter of the outer tube can be reduced, and the cost is reduced.
However, in order to bring the outer tube and the inner tube into strong contact with each other, as shown in claim 2, there is not only a difference in yield stress, but also as shown in the specification, the material constituting the inner tube is lowered. The state stress needs to be larger than the yield stress of the material constituting the outer tube, and is specified in the specification.

Patent Document 3 proposes a double-pipe hydroform processing method. Here, a gap is formed between the outer pipe and the inner pipe, and only the outer pipe is deformed so that the gap between the inner and outer pipes is reduced. A method for obtaining an open double tube is described, but not a configuration in which the inner and outer tubes are closely formed.
Therefore, it is difficult to use as a heating tube from the viewpoint of heating efficiency.

  Further, it has been practiced to install fins in a conventional heating tube to capture exhaust heat, efficiently transfer the heat to the heating tube, and heat the fluid in contact with the heating tube (Patent Document 4). This heating tube is formed in such a way that the tube can be divided, and the work of installing the fins requires several steps such as temporary spot welding and brazing of the fins in the pipe, depending on the material, seam welding, high frequency welding For example, it is necessary to select appropriate application fixing means, and each work is required.

  Also, the thermal efficiency varies greatly depending on the shape and installation location of the fin, and it is necessary to select and determine the shape of the fin according to its usage state, and to manufacture various shapes corresponding to each usage state, It is difficult to make and use ready-made products.

  Further, in the case of a structure in which the fin is fixed in the pipe, it is difficult to prevent the heating efficiency from being deteriorated due to damage, distortion, or dropping of the fin due to heating.

Further, as shown in Patent Document 5, a device for heating a liquid in a liquid tank, for example, water, oil, etc., through a heating tube into the liquid tank, for example, boiled or fried has been proposed. Since several of them are installed in parallel, it is difficult to clean the bottom of the tank, and further, it is a normal stainless steel tube, and has disadvantages such as poor thermal efficiency.
In addition, although a single copper tube has good heating efficiency, it is weak in structure, and when used as a heating tube for liquids, particularly in a cooking machine, it may cause corrosion, patina, etc., and connection processing with other tubes. There are problems in use such as difficulty.

  As described above, it is difficult to form a double metal tube by a conventional method and apparatus, and it is difficult to form a double metal tube. Further, it is considered that this double metal tube is used as a heating tube. In view of the current situation, the present invention aims to obtain a heating pipe or exhaust pipe that can be manufactured very easily in order to solve the above-mentioned problems.

  In addition, since it is a heating pipe or exhaust pipe configured with a very simple structure, it is possible to manufacture various types of pipes, easy to manufacture off-the-shelf products, and extremely low manufacturing costs. The purpose is to provide.

It is another object of the present invention to obtain a heating tube or exhaust tube having a rigid structure that does not damage or damage the product part due to heating.
Another object of the present invention is to obtain a heating pipe and an exhaust pipe that have extremely good thermal efficiency and extremely good heating efficiency of fluids such as water and oil that come into contact therewith. In order to achieve the above object, the following configuration is proposed.

  In order to solve the above-mentioned problems, the present invention is a double pipe made of an outer pipe formed of a steel pipe or a stainless steel pipe, and an inner pipe made of copper or a copper alloy, and the inner and outer pipes are configured to be in close contact or pressure-bonded. This is a heating tube.

  Further, the heating pipe is characterized in that a bulging portion having a desired shape is formed on the double pipe so as to protrude in the inner pipe inward direction or in the outer pipe outer direction.

  In addition, the bulging portion is a heating tube characterized in that it is formed in an irregular shape alternately in a ring shape with a desired width at a desired interval.

  Further, the bulging portion is a heating tube characterized in that the cross-sectional corrugation continues.

  Moreover, the external pressure to the said both pipe | tubes is a heating pipe | tube characterized by being performed by hydroforming shaping | molding process.

  Moreover, it is a heating cooking machine characterized by installing the said heating pipe | tube in the liquid tank.

  In addition, the heating cooker is characterized in that a plurality of heating tubes are installed in parallel in the liquid tank.

  The heating cooker is characterized in that the heating pipe is erected in the liquid tank.

According to the present invention, copper or copper alloy having excellent thermal efficiency is used as an inner tube to sufficiently absorb combustion heat such as combustion gas that passes through the inner tube, and heat is transferred to the outer tube that is in close contact with the inner tube. Thus, the liquid in contact with the outer tube can be efficiently heated.
In addition, the inner tube can be protected by forming the outer tube with a hard material of steel or stainless steel because the copper or copper alloy of the inner tube is soft and easily damaged.

The heating tube of the present invention can be brought into close contact or pressure bonding by inserting the inner tube into the outer tube and applying a partial pressing force from the outer tube outer side or from the inner tube inner side, and its manufacture is extremely easy. .
Further, by press molding, pressure molding can be performed from the inner side of the inner tube by hydroforming from the outer side of the outer tube, and its manufacture is simple and the manufacturing cost is extremely low.

  In addition, the pressure from the inside of the inner tube or the outside of the outer tube promotes the integration of the two tubes, and the formation of the bulging portion inside and outside forms irregularities on the inner surface of the tube, and captures the combustion heat passing through the inner tube Is performed very efficiently, and a heating tube with high thermal efficiency is obtained.

It is a vertical side view of one embodiment of the present invention. FIG. 6 is a side view of another embodiment of the present invention. It is a side view of the other embodiment of the present invention. FIG. 6 is a side view of another embodiment of the present invention. FIG. 6 is a side view of another embodiment of the present invention. It is a schematic explanatory drawing of a boiled noodle machine using one embodiment of the present invention. It is a boiled noodle machine schematic explanatory drawing using this invention other implementation goods. It is a boiled noodle machine schematic explanatory drawing using this invention other implementation goods. It is boiled noodle machine bottom explanatory drawing using this invention other implementation goods. It is channel explanatory drawing used for the boiled noodle machine using this invention other implementation goods. It is channel explanatory drawing used for the boiled noodle machine using this invention other implementation goods. It is channel explanatory drawing used for the boiled noodle machine using this invention other implementation goods. It is channel explanatory drawing used for the boiled noodle machine using this invention other implementation goods.

The present invention will be described with reference to FIG.
The heating tube 1 of the present invention is a double heating tube, and the inner tube 3 is inserted into the outer tube 2 so as to be closely attached and fixed.

Reference numeral 2 denotes an outer pipe that uses a steel pipe or a stainless steel pipe. The steel pipe is convenient for use in high temperature, high pressure pipes and heat exchanger steel pipes, and the stainless steel pipe is convenient for use in alloy steel pipes containing stainless steel pipe Ni, Cr, etc. for piping. is there.
As the stainless steel tube, austenite (18Cr, 18Ni) SVS304 is often used. The thermal conductivity of the SVS 304 is 0.039 (cal / c, cm, sec). Also, a ferrite type (18Cr type) is used, and its thermal conductivity is 0.063.

Reference numeral 3 denotes an inner tube made of copper or a copper alloy, and oxygen-free copper (alloy number 1020), tough pitch copper (alloy number 1100), and phosphorus deoxidized copper (alloy number 1220) each have a thermal conductivity of 0.93. 0.93, 0.81 (cal / c, cm, sec), which is high in convenience.
Moreover, H3601 seamless copper pipe, H3603 deoxidized copper pipe, etc. are prescribed | regulated by JIS as a copper pipe and a copper alloy pipe. As this manufacturing method, various existing methods can be used.

  In forming the double pipe according to the present invention, first, there is a step of inserting the inner pipe 3 which is a copper alloy pipe into the outer pipe 2 which is a stainless steel pipe. At this time, it is preferable that the gap between both pipes be made as small as possible. The thickness of both tubes 2.3 is preferably 2 mm or less, and 1.0 to 1.8 mm is convenient for use. The outer diameter of the heating tube is often 80 mm or less. Pressure is applied to the double pipe 1 of the inner pipe 3 and the outer pipe 2 from the inner side of the inner pipe 3 or from the outer side of the outer pipe 2 so as to be integrated with the double pipe 1.

When pressure is applied from the outside of the outer tube, for example, using a roll molding method, ring-shaped bulging portions, here grooves 31 and 21 are formed by rotation of the roll, and the grooves 31 and 21 are formed at appropriate intervals. Bellows-like double pipe 1 is formed by alternating peak portions 32 and 22. Due to this roll pressure, the outer tube 2 and the inner tube 3 are brought into close contact or pressure-bonded, and a bellows-like double tube 1 is formed.
3 and FIG. 5, in the above roll molding method, when a roll having protrusions and protrusions is used instead of the roll, the double pipe 1 is disposed between the protrusions and protrusions. When the concave portions are formed at the desired intervals and are formed at the desired intervals, the inner and outer tubes 2 and 3 are adhered and fixed.
As the bulging portion, other cross-sectional corrugated shapes that are continuous or intermittent in the longitudinal direction and various protruding shapes can be formed.
Of course, the formation of these bulges and the close contact and crimping of the inner and outer tubes can also be performed by other methods, for example, pressure molding by a pressing method.

Of course, it has never been proposed or proposed that the double heating tube of the present invention is manufactured by these methods. Another method is a hydroforming method. This method is common to the point that the double pipe described in the cited document 3 is mounted on a mold and clamped.
However, the cited document 3 is characterized in that the first mold and the second mold are used first, and that only the outer tube is deformed in the second step to form a gap in the inner and outer tubes.

  On the other hand, in the present invention, a double pipe is constructed in which the inner and outer pipes are integrated and molded, and at the same time, closely adhered and fixed. In the present invention, since the purpose is to form a double pipe in which the inner and outer pipes are in close contact with each other, pushing the split mold in the pipe axis direction is nothing or only gives unevenness, and it can be very little and into the pipe. The objective can be achieved with a single internal pressure.

  Further, hydroforming as a method for forming the double pipe shown in FIGS. 2 and 4 will be described. Similar to the normal hydroforming method, by placing a double pipe on the split mold, after clamping the mold, the outer pipe 2 and the inner pipe 3 are axially pressed and simultaneously the inner pipe 3 is loaded with pressure. The bulging portions 22, 22... Of the split mold project from the inner tube 3 and the outer tube 2, and the bulging portions 32, 32. The At this time, when the bulging portions 22 and 22 are formed to be large or high, the amount of axial push against the outer tube 2 and the inner tube 3 increases, and in this case, a plurality of molds can be used.

Further, when the bellows-like double pipe shown in FIG. 1 is formed, the axial push amount with respect to the outer pipe 2 and the inner pipe 3 becomes large as described above. Several bulges on both sides are preferably formed sequentially, and it is convenient to use several molds according to the length of the bellows.
A method called a composite bulge processing method can also be used. This is because the interlocking mold is installed in a ring shape divided in the housing, the double pipe 1 is put into this mold, the hydraulic pressure is applied from within the double pipe 1, and the interlocking mold is moved, The double pipe 1 is swelled between ring-shaped molds and formed into a bellows shape.

Thus, the copper or copper alloy tube 3 excellent in heating efficiency is used as the inner tube, the combustion gas is efficiently absorbed, and the stainless steel tube excellent in mechanical strength such as tensile strength, elongation and hardness is used as the outer tube. The inner tube can be protected and the inner tube 3 can be heated efficiently through the outer tube 2 and the liquid in contact with the outer tube 3.
Further, due to the material properties such as the spreadability and drawing workability of the copper or copper alloy, it is surely integrated by being in close contact with or crimped to a stainless copper pipe having excellent mechanical properties.
In particular, due to the configuration of the bulging portion, close contact or pressure bonding between the inner tube 3 and the outer tube 2 is more reliably achieved.

In the double pipe in the present invention, the inner pipe 3 through which the combustion gas passes has a high thermal conductivity, sufficiently captures and holds the heat of the combustion gas, and passes slowly through the inner pipe 3. On the other hand, the outer tube 2 is considered to pass through the outer tube 3 quickly because the outer tube 2 receives and releases heat from the inner tube 3 and has a lower thermal conductivity than the inner tube and has a low retention rate. It is thought that it is quickly transmitted to the surrounding liquid.
Further, the heating area of the tube 1 increases due to the unevenness of the tube 1, and in particular, in the case of a bellows tube, it can be 3 to 10 times.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
6 to 9 show an embodiment in which the present invention is used in a boiled noodle machine.
In the figure, reference numeral 4 denotes a housing, which is formed in a box shape from stainless steel or the like. It is also possible to install columnar bodies at the four corners as necessary. 5 is a liquid tank installed in the upper part of the housing 4 and is formed in a box shape covering almost the entire inner surface of the housing 4. The liquid tank 5 is usually made of stainless steel, and SUS304 and 18Cr-8Ni, which are representative steel types, are widely used.

  The liquid tank 5 is composed of four side walls 51, 51, 51, 51 and a bottom 52. Like the case 4, the liquid tank 5 has a long front and rear depth and a planar quadrilateral shape. Is not to be done.

The heating tube 1 is configured as an L-shaped tube including a horizontal portion 12 and an upright portion 13, and one end is installed in the opening 53 provided in the bottom portion 52 of the liquid tank 5 with or without the connecting tube 11, and the other end is upright. The upper end of the part 12 is connected to the discharge part. It is preferable to install 2 to 4 heating tubes 1 according to the size of the liquid tank 5. The heating tube 1 passes through the combustion gas from the combustor 50 positioned below the opening 53 of the bottom 52 and absorbs heat very efficiently by the copper or copper alloy tube 3 serving as the inner tube, thereby heating the outer tube 2. And heat the surrounding liquid such as water.
In addition, when the heating tube 1 is an L-shaped tube, the heat exhausted by the normal chimney is also efficiently absorbed to increase liquid heating.

Further, the heating tube 1 can be formed as a straight tube, installed from the front surface of the housing 4 to the rear surface of the housing, and the combustor 50 can be provided at the front portion of the housing 4 so that combustion gas can be blown into the heating tube 1.
Further, the heating tube 1 can be erected and installed on the bottom 52 at the back of the liquid tank 5. At this time, it is convenient to install a plurality of heating tubes 1, but the heating tube 1 may be configured widely and a single installation may be used.
When the heating pipe 1 is erected, the combustor 50 can be installed at the front of the housing 4 and the combustion gas passage can be placed under the bottom 52 to serve as a heating auxiliary unit.

  Desired legs 43, 43, 43, 43 are provided at the lower part of the housing 4, but are short for the desktop type and formed at a desired height for the floor-mounted type.

  In the present embodiment, the liquid in the liquid tank 5 is heated only by the heating tube 1 in the first embodiment, and in addition, the bottom 52 of the liquid tank 5 is also heated.

Reference numeral 6 denotes a bottom plate provided in the housing 4. The bottom plate is disposed at an appropriate distance from the bottom 52 of the liquid tank 5 and substantially parallel to the bottom 52. A combustion gas flow path 7 is formed between the bottom plate 6 and the bottom 52 of the liquid tank 5. In the opening 81 provided near the front of the casing 4 of the bottom plate 6, flame ports 82, 82... And burner heads 83, 83, 83 are installed. The burner head 83 communicates with the nozzle 85 via the mixing tube 84 and communicates with the pressure regulator and the gas valve. The combustor 80 is configured by these known mechanisms. An opening 53 is provided in the bottom 52 near the rear of the housing 4 at an appropriate distance from the side wall 51, and the opening 53 serves as a discharge port, communicates with the combustion gas flow path 7, and faces the opening 53. Then, the heating tube 1 is erected.
A drooping plate 54 that is suspended from the vertical line of the front end side wall 51 of the liquid tank 5 is fixed at the bottom plate 6 and one end thereof, and serves as a starting end of the combustion gas flow path 7. A drooping plate 55 suspended from the bottom line of the side wall 51 at the rear end of the liquid tank 5 is fixed to the other end of the bottom plate 6 and serves as an end of the combustion gas flow path 7.

  The heating tube 1 is formed using a stainless steel tube and a copper tube, but it is recommended to form and use a bellows tube. The upper end of the heating tube 1 protrudes from the upper end of the housing 4.

Channel pieces 9 are arranged and installed on the bottom 52 of the liquid tank 5 to increase the heating efficiency.
The channel piece 9 is formed in an L shape (9A) or a U shape (9B) by planting or folding side plates 92, 92 or 92 on both side ends or one side of a rectangular small plate 91.
It can also be formed in an inverted T shape. Alternatively, the small plate 91 is formed in a rhombic shape formed at an appropriate angle with respect to two parallel sides, and the side plates 92, 92, or 62 are folded into two parallel sides or one piece, and an L-shaped cross section is formed. (9C).
A channel piece (9D) in which the small plate 91 is formed in a curved shape and the side plates 92, 92 or 92 are formed in accordance with the small plate 91 can also be used.

The installation of the channel piece 9B, that is, the channel piece B having both side plates 92, 92 will be described as an example.
The arrangement is such that the channel piece 9 is placed in front of the housing 4 in a state in which the side plates 92 are in contact with each other in parallel. This parallel arrangement is not necessarily aligned, and the front end may be in and out. In this case, the side plates 92 and 92 that contact each other of the adjacent channel pieces 9 are preferably installed in close contact with each other, but may be installed at an appropriate interval therebetween.

Further, in the case of an L-shaped channel piece, it is arranged in contact with the side plate 92 of one channel piece 9 and the small plate 91 of the adjacent channel piece 9, but it is also possible to put some space between them.
Further, when the channel piece 9 is connected, it is possible to combine the channel pieces 9B and 9A. When installing each channel piece 9, bolts are fixed in place by studless welding or the like in advance, and are passed through mounting holes 93, 93 provided in the small plate 91 of the channel piece 9, so that the small plate 91 is placed in the bottom 52. It is convenient to fix it with a nut.

Of course, the back surface of the small plate 91 is also welded to the bottom surface of the bottom 52 by other welding methods. However, the welding method is difficult, and there is a drawback in that the bottom portion is easily deformed and a failure such as welding peeling is likely to occur. On the other hand, the bolts and nuts are securely fixed, and the operation is simple and inexpensive.
In addition, the small plate 91 of the channel piece 9 and the bottom portion 52 of the liquid tank 5 are firmly and reliably adhered, and the thermal efficiency is extremely good.

When the second-stage channel pieces 9, 9, 9,... Are connected following the front-row channel pieces 9, 9, 9,..., The side plates 92, 92 of the front and rear channel pieces 9, 9, 9. The side pieces 92, 92 of the channel pieces 9, 9, 9 can be shifted from side to side so that they do not overlap.
Further, the third and fourth stages are connected in the same manner. Moreover, the connection of a front | former stage and a back | latter stage can also be installed at appropriate intervals.

  The channel pieces 9, 9... Arranged in parallel with the preceding stage are formed with grooves 94 formed by the side plates 92 and 92 and the small plates 91 of each channel piece 9, and each groove 94 continues as a combustion gas flow passage. . The side plate 92 and the side plate 92 of the next channel piece 9 are shifted from each other and the groove 94 and the next stage groove 94 are connected to each other. The flow path is divided by the side wall 92 in the next groove 94, and the combustion gas is divided into two parts. In the stage, the halved combustion gases merge or flow to another adjacent channel piece 9. In this way, the flow of the combustion gas is repeatedly divided or merged.

  Thus, “When a line is hypothesized in a moving fluid at a certain moment, if a tangent drawn to an arbitrary point above it indicates the direction of the flow velocity at that point, this line will flow. According to the definition of “line”, the channel piece 9 and the succeeding channel piece 9 are shifted left and right, and the side plate 92 is placed between the small plates 91 and 91 of the channel piece 9 in the preceding stage. It is a configuration.

And it can be said that shifting the channel piece 9 and the succeeding channel piece 9 is a change of the combustion gas flow path, and that part is the structure of the change part of the streamline.
Also, according to the definition of “a certain minute part in a fluid or a completely floating fine particle, and a line that passes with time is called a flow path”, it is also called “change of flow path”. I can do it.

In any case, a configuration or a part that causes a change in the flow of fluid in the flow path can be referred to as a streamline changing unit.
Further, it is considered that the fluid flow is changed by the flow line changing portion, and when the flow line is not changed, the fluid flow becomes turbulent due to the bending as compared with the laminar flow, thereby causing the diffusion delay of the flow velocity. This point leads to an increase in the heating rate.
At the same time, the gas flow is turbulent by changing the flow line, and the combustion gas repeatedly strikes each side plate 92 of the channel piece 9 to efficiently transfer the heat of the combustion gas to each channel piece 9.

By changing these streamlines, the flow path of the combustion gas fluctuates, the time for contacting each small plate 91, 91 of the channel piece increases, and the contact area also increases per hour, so that heating energy is supplied to the channel piece 9 Is increasing.
As a result, the rise in the liquid temperature in the liquid tank was remarkable, the energy consumption was kept low, and extremely efficient cooking became possible.

The channel pieces 9, 9, 9... Are directly transferred to the channel piece 9 because the small plate 91 is in close contact with the liquid tank bottom 52, and the bottom 52 is heated and transferred to the liquid in contact with the bottom 52. Heat it and heat it.
When the channel pieces 9, 9, 9... Are copper, the thermal conductivity is 0.93 (cal / c · cm · sec), compared with 0.04 (cal / c · cm · sec) of stainless steel. However, it is simply 23 times or more.
Examples of the copper include phosphorous deoxidized copper, oxygen-free copper, and tough pitch copper. Phosphorus deoxidized copper is convenient for use.

This channel piece 9 is heated very efficiently, and in order to retain heat, the adjacent channel pieces 9, 9, 9... And the bottom 52 where the channel pieces 9, 9, 9. Conduct heat and heat efficiently.
The combustion gas portion that does not reach the channel pieces 9, 9, 9..., The combustion gas portion that does not come into contact with the channel piece 9 travels in the flow path 7, heats the flow path 7, and the channel pieces 9, 9, 9. The opening 53 is reached while assisting heating in the flow passage formed at the bottom.

By the heating structure as described above, the combustion gas efficiently heats the bottom 52 of the liquid tank 5 through the channel pieces 9, 9,..., And is transferred to the liquid in contact with the bottom 52 by the heating of the bottom 52. To accelerate heating.
The energy of the combustion gas thus heated is greatly transferred to the liquid, and the liquid temperature is increased efficiently.

  On the other hand, the combustion gas that reaches the opening 53 through the flow path of the channel pieces 9, 9, 9,... Rises up the heating pipes 1, 1, 1,. The energy remaining in the combustion gas heats the heating tubes 1, 1, 1, heats the surrounding liquid according to the temperature, and accelerates the temperature rise of the liquid.

  By heating the channel pieces 9, 9, 9... And the heating pipes 1, 1, 1, most of the combustion energy is consumed and rises. The liquid in the liquid tank 5 is heated by both surfaces of the bottom 52 and the heating pipes 1, 1, 1 planted in the liquid tank 5, and the temperature rise of the liquid is efficiently accelerated. At the same time, the combustion gas energy is quickly and sufficiently transmitted to the liquid, and the liquid temperature can be increased in a short time.

Furthermore, the remainder of the combustion gas that has risen in the heating tubes 1, 1, 1 reaches the water storage tank 100, rises from openings 84, 84, 84 opened in the bottom 83, and is planted there. , 101 and 101 are heated to rise and become extremely low temperature and discharged.
The water in the water storage tank 100 is heated by the heating of the second heating pipes 101, 101, 101. The heated water overflows from the overflow pipe 102 and is supplied into the liquid tank 5 through the opening 105.

Reference numeral 44 denotes a discharge port provided in the bottom 52, which communicates with the discharge pipe 57.
Reference numeral 46 denotes an overflow groove formed at the upper edge of the liquid tank 5, a discharge port 47 is formed at the end thereof, a discharge pipe 48 is provided at the lower part thereof, and a discharge pipe is provided below the discharge pipe 48. 57 is connected.

The bellows double pipe shown in FIG. 1 of the present invention and a straight pipe double pipe simply inserted with a copper pipe through a stainless steel pipe were installed in the boiled noodle machine shown in the examples, and the measured values of the respective thermal efficiencies were determined.
Bellows double pipe outer diameter 76mm
Water: 43 l
Boiling time: 37 minutes 23 seconds Straight pipe Double water: 43 l
Boiling time: 43 minutes 46 seconds The bellows tube is about 12-13% boiling fast.

DESCRIPTION OF SYMBOLS 1 Double pipe 2 Outer pipe 22 Bulging part 3 Inner pipe 4 Case 43 Leg 5 Liquid tank 51 Side wall 52 Bottom part 6 Bottom plate 7 Flow path 8 Water tank 9 Channel piece 100 Water tank

Claims (8)

  A heating tube comprising an inner tube made of copper or a copper alloy and an outer tube made of a steel tube or a stainless steel tube, wherein the inner tube and the outer tube are in close contact or pressure bonded.   2. The heating tube according to claim 1, wherein a bulge portion having a desired shape is formed on the double tube so as to protrude in an inner tube inner direction or an outer tube outer direction at a desired portion.   The heating tube according to claim 1 or 2, wherein the bulging portions are alternately formed in an uneven shape in a ring shape having a desired width at a desired interval.   The heating tube according to any one of claims 1 to 3, wherein the bulging portion has a cross-sectional corrugated shape.   The heating pipe according to any one of claims 1 to 5, wherein the external pressure applied to both the pipes is performed by a hydroforming molding process.   A heating cooker characterized in that the heating pipe shown in any one of claims 1 to 5 is installed in a liquid tank.   The heating cooker according to claim 6, wherein a plurality of heating tubes are installed in parallel in the liquid tank.   The heating cooker according to claim 6 or 7, wherein the heating pipe is erected in the liquid tank.

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