JP2012057892A - Heater for generating hot air - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater for generating hot air, which enables weight reduction, resource saving, and low cost by enhancing performance with a simple constitution.SOLUTION: An insulator 12g is installed in a nearly cylindrical heater container 11 with a supply hole 22 at one end and a discharge hole 20 at the other end. A plurality of air flow holes with nichrome wires provided therein are installed in the insulator 12g, and the air supplied via the supply hole 22 is circulated through the air flow holes of the insulator 12g for heating. The high-temperature hot air is discharged from the discharge hole 20. The insulator 12g is formed of a plurality of disc-like plates each of which has a predetermined thickness. The air flow holes are provided in the axial direction thereof and a plurality of insulators 12g are aligned one by one substantially in parallel in the air flow direction at intervals. The distance is set in the range from half to twice the thickness of the insulator 12g.

Description

  The present invention relates to an improvement of a hot air generating heater for discharging hot hot air by connecting to a blower or the like.

A conventional heater for generating hot air of this type and an insulator used in the heater are shown in FIGS. FIG. 6 is a perspective explanatory view of an insulator, and FIG. 7 is a conceptual explanatory view of a heater for generating hot air.
The insulator 50 shown in FIG. 6 is a so-called lotus root insulator having a columnar shape, and a large number of through holes 52, 52,... Are provided in the axial direction, and a nichrome wire or the like is provided in each of the through holes 52. A heating wire is wired.

The blown gas flows in the axial direction (gas flow direction) D, passes through the through holes 52, and is heated. No protrusion or protrusion for supporting the nichrome wire is provided on the inner wall surface of each through hole 52.
An appropriate number of the insulators 50 are arranged in the axial direction, overlapped so that the positions of the respective through holes 52 coincide with each other, and arranged in the heater for generating hot air.

FIG. 7 shows a hot air generating heater 60 in which the insulator 50 is disposed.
Four insulators 50 are arranged in series in the axial direction (gas flow direction D) in a heater housing 65 having a gas supply port 61 on the right end side in the drawing and a hot air discharge port 62 on the left end side in the drawing. Is fixed.

  The number of the insulators 50 arranged is appropriately determined according to the capacity of the heater. When arranging the insulators 50, the positions of the respective through holes 52 are arranged at the same position. Then, as indicated by the two-dot chain line in the figure, a nichrome wire is wired in these through holes 52 from the supply port 61 side to the discharge port 62, and then from the discharge port 62 side to the supply port 61 side. Wiring one after another in a zigzag pattern. By setting the number of through holes 52 of the insulator 50 to an even number, both terminals of the nichrome wire can be positioned on the supply port side.

Each insulator 50 is fixed by a long-axis bolt 66 and a nut 67. These bolts and nuts are fixed using two to four places of any through holes 52 provided in the insulator 50.
Although not shown, a temperature sensor such as a thermocouple for preventing abnormal overheating can be disposed in any of the through holes 52 located in the central portion. In this case, the nichrome wire wound spirally is inserted into the central portion and arranged.
The discharge temperature detection sensor T that detects the discharge temperature is disposed from the outside of the heater housing 65 in front of the insulator located closest to the discharge port in the heater housing 65.

Further, the applicant of the present application has previously proposed a so-called ring insulator described in Patent Document 1 below.
Such a ring insulator has a cylindrical shape with a short length in the axial direction. An insertion hole for inserting a temperature sensor or the like is provided in the central portion, and a nichrome wire is wired in the outer peripheral portion of the central portion. A plurality of heating wire insertion portions to be formed by a radial partition frame.

A plurality of ring insulators are used in the axial direction according to a desired capacity, but the maximum gas discharge temperature cannot be increased to 500 ° C. or more because of the structure. Therefore, it cannot be used as an insulator for a heater for generating high-temperature hot air according to the present invention.
In other words, this ring insulator is of a category different from the heater insulator for generating high-temperature hot air of 800 ° C. or higher according to the present invention.

The reason for this is that in the case of a heater insulator that discharges hot hot air of 800 ° C. or higher, the air speed is increased to a certain level or higher (in order to heat the heated air to near the heat-resistance limit temperature of the heating wire, It is necessary to increase the exchange efficiency), and the uniformity of the air volume that passes through each gas circulation hole is required, so the heated blown gas is passed through a certain narrow space (passage) and wound It is necessary to force contact with the nichrome wire, but in the case of the above ring insulator, it is considered that the air volume hitting each heating wire cannot be made uniform because the nichrome wire is only supported by the partition frame. It is.
If the wind speed cannot be kept constant, the surface temperature of the heating wire wired in each hole will be different, which will not improve the overall heat exchange efficiency, and will limit the maximum discharge temperature. It is considered.

The problems of the conventional example are listed as follows.
The heating wire wired to the insulator extends in the direction in which the force is applied due to a sudden increase in the blown gas (change in the wind speed passing through the through hole) or gravity (heating wire wound in a spiral shape). The distance (pitch) between adjacent lines of the wire becomes uneven), and the amount of air passing through each through hole changes due to abnormal overheating, which makes it possible to discharge hot hot air safely over a long period of time. Absent.

  When high-temperature hot air of 800 ° C. or higher is discharged, the surface temperature of the heating wire becomes about 900 ° C. or higher, but a phenomenon occurs in which the heating wire jumps out of the insulator outlet side due to the wind pressure of the blown gas. In addition, when the discharge port is directed downward, gravity is also applied, and the problem of heating wire expansion and pop-out becomes more serious. It is considered that problems such as the jumping out of the heating wire may be promoted by the vibration of the heating wire caused by the magnetic field when a current is passed through the heating wire.

The vibration of the heating wire is generated not only by the magnetic field but also by mechanical vibration. By the generation of such vibration, the nichrome wire and the through hole are brought into frictional contact, and the oxide film of the heating wire is scraped (polished), Alternatively, if the inner wall surface of the insulator is polished and becomes dust and protrudes to the outside, adversely affecting the environment, and if it accumulates in the through hole, it may cause disconnection of the heating wire.
Heating wire is not sufficiently held by the insulator and is weak against mechanical vibration or magnetic vibration. Since the heating wire is simply inserted through the through hole of the insulator and wired, the heating wire is not held or fixed by the insulator.

Conventionally, in order to prevent the heating wire from jumping out as described above, there has been provided a means for preventing the jumping at the end of the insulator on the discharge port side. However, even if this means for preventing popping out is provided, the heating wire wired to the insulator is not provided with any means for holding or fixing in the through hole of the insulator, and the amount of air passing through each hole, heating, etc. It did not solve the harmful effects caused by uneven pitch of the heating wire due to the above, problems caused by vibration, and the like.
A plurality of insulators are fixed by tightening a long bolt and nut using two to four through holes, but the heated gas cannot be circulated through the through holes, It cannot be made compact.

A temperature sensor such as a thermocouple for preventing abnormal overheating is arranged in the center of the spirally wound nichrome wire wired in the through hole located in the center portion. The flow of air in the hole is obstructed, and the heating wire in the hole has less air volume to pass compared to the heating wire in the other hole, and the heating wire in the other hole becomes more superheated, which makes the sensor The temperature detected by will always indicate a somewhat higher temperature, and complete temperature control is not possible. Therefore, the maximum operating temperature has to be set a little lower empirically considering the safety of the heating wire.
The temperature sensor of the discharge gas is wired from the outside to the discharge port side portion of the heater housing 65, and the wiring becomes an obstacle or does not look good.

  Therefore, the inventor of the present application is a heater insulator capable of discharging hot air at a temperature of 800 ° C. or higher, and is resistant to vibrations caused by magnetic fields and mechanical vibrations without causing uneven pitch of the heating wire, and a hot air discharge port. The heating wire can be effectively held and fixed even if it is directed in any direction, and it is possible to prevent the heating wire from popping out even when it is directed downward, and the heat from the heating wire to the gas can be prevented. Offering a heater that can improve the thermal efficiency of the heated gas without affecting the exchange efficiency, and that can discharge high-temperature hot air that is stable over a long period of time, and also provides a heater for generating high-temperature hot air using this insulator For that purpose, an insulator and a heater for generating hot air described in Patent Document 2 below have been proposed.

Japanese Utility Model Publication No. 1-334790 Table 2005/78357

In the invention described in Patent Document 2, the insulator itself is formed from a plurality of constituent pieces and stacked, and the heating wire is held in a twisted state by slightly shifting the position of the gas flow holes of the adjacent insulator constituent pieces. In other words, the above-mentioned problems have been solved as a configuration that can securely hold the heating wire.
An object of the present invention is to improve the conventional heater for generating hot air, and it is an object to manufacture a heater for generating hot air having a simpler configuration.

And unlike the thing of the said patent document 2, even if an insulator itself does not hold | maintain a heating wire by devising the combination of an insulator and a heating wire, high temperature hot air of 800 degreeC or more is discharged without any problem. The problem is to provide a heater for generating hot air.
Furthermore, its weight reduction, resource saving, compactness, and cost reduction are also achieved, and the performance is further improved without degrading its performance even when compared with conventional heaters. It is also an object of the present invention to improve the heat exchange efficiency to the blown gas and to obtain a discharge gas temperature equal to or higher than the conventional one even if the flow rate or flow rate of the blown gas is smaller. .

  In order to solve the above-mentioned problems, in the first aspect of the present invention, an insulator is provided inside a substantially cylindrical heater housing body in which a gas supply port is provided at one end portion and a discharge port is provided at the other end portion. A large number of gas flow holes provided in the insulator are provided with heating wires, and the blown gas supplied from a blower or the like through the supply port is passed through the gas flow holes of the insulator and heated. In the hot air generating heater for discharging hot hot air from the discharge port, the insulator is formed from a plurality of disc-shaped members having a predetermined thickness, the gas flow holes are provided in the axial direction, and each of the plurality of insulators is provided one by one. A heater for generating hot air, characterized in that the heaters are arranged in a row in the air blowing direction at intervals in parallel, and the intervals are set to a distance corresponding to about 1/2 to about 2 of the thickness of the insulator.

According to a second aspect of the present invention, in the first aspect of the present invention, in the gas flow hole of each insulator, the maximum inner diameter of the gas flow hole located in the central portion is greater than the maximum inner diameter of the gas flow hole located in the outer peripheral portion. Is a heater for generating hot air.
Here, the "maximum inner diameter" of the gas flow hole is the reason why the inner diameter of the gas flow hole is larger than that of the portion other than the protrusion in the sixth invention. It is intended.

  According to a third aspect of the present invention, there is provided a hot air generating heater according to the first or second aspect, wherein the distance between the insulators is gradually reduced from the supply port side toward the discharge port side. is there.

  According to a fourth aspect of the present invention, in the first to fourth aspects of the present invention, at least two screw insertion holes are provided at appropriate positions in the axial direction of the respective insulators, and long-axis screws are inserted into these screw insertion holes. A heater for generating hot air is characterized in that a spacer is interposed between each insulator and a nut is screwed to fix each insulator at a predetermined interval.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the temperature sensor is inserted into at least one of the gas flow holes formed in the central portion of each insulator where the heating wire is disposed. It is a heater for generating hot air, characterized in that a space that can be formed is formed.

  According to a sixth aspect of the present invention, in each of the above inventions, a plurality of protrusions supporting the heating wire are provided in the gas flow direction on the inner wall of the gas flow hole of each insulator where the heating wire is disposed, It is a heater for generating hot air, characterized in that a wound heating wire can be supported in a gas flow hole while maintaining a distance from its inner wall.

  According to a first aspect of the present invention, in the hot air generating heater, the insulator is formed from a plurality of disk-shaped members having a predetermined thickness, the gas flow holes are provided in the axial direction, and each of the plurality of insulators is provided one by one. Arranged in a row in the air blowing direction with a spacing approximately parallel to each other, and by setting the spacing to a distance of about 1/2 to about 2 pieces of the thickness of the insulator, that is, the insulator on which the heating wire is arranged By arranging at predetermined intervals, the blown gas heated in the gas flow holes of each insulator is once mixed and mixed between the insulator and insulator.

By mixing and mixing the blown gas between the insulators, the temperature unevenness of the blown gas is eliminated, and a constant temperature increase is realized. This is repeated between each insulator, and as a result, the efficiency of heat exchange with the blown gas is further improved.
Here, since the outer diameter of the insulator can be set as large or small as appropriate, the interval distance cannot be limited by a specific numerical value. Therefore, the outer diameter is specified by a relative ratio between the thickness of the insulator and the interval distance. ing.
When the thickness of the insulator is as thin as about 10 mm, for example, it has been confirmed by experiments that the interval distance can be increased to some extent, for example, about 20 mm, which is twice that distance.

In order to improve the heat exchange efficiency, the present inventor repeated many experiments on the relationship between the insulator and heating wire as described above, and as a result of earnest research, the ideal thickness of the insulator was about 25 mm. It was discovered that the spacing between each insulator was about 13 mm.
Then, it was found that the region where the heat conversion efficiency is good is an interval of about ½ to about 2 pieces of the thickness of the insulator, and it was conceived that this range is a very good range.
Therefore, this range is limited in claim 1.

Moreover, the air volume which passes through each gas circulation hole can also be made into substantially the same quantity by the space | interval between this insulator, and the heat conversion efficiency from a heating wire to blowing air can be improved more.
Furthermore, in the present invention, the amount of the insulator used can be made extremely small as compared with the conventional one. That is, since a gap is provided between the insulators, the amount of the insulator used is greatly reduced. Since it can be reduced, it will greatly contribute to resource saving, weight reduction, and cost reduction.

In the present invention, as described above, in order to improve the heat conversion efficiency, we have earnestly studied about the relationship between the heating wire and the insulator, but in the insulator arranged at intervals, When the heating wire is heated, the central portion becomes the highest heat.
Therefore, in the second embodiment of the present invention, in order to improve the heat conversion efficiency as much as possible, the maximum inner diameter of the gas flow hole located in the central portion is set to the maximum inner diameter of the gas flow hole located in the outer peripheral portion. It is set slightly larger than.
As will be described later, in this embodiment, the maximum inner diameter of the gas flow hole in the central portion is designed to be about 4% larger than the maximum inner diameter of the gas flow hole provided in the outer peripheral portion.
Although this is a little efficient, the heat conversion efficiency from the heating wire to the blown gas is increased.

In the third aspect of the present invention, in consideration of the arrangement of the respective insulators, the interval distances are not all fixed, but the interval distances are gradually reduced from the supply port side toward the discharge port side. However, this point is limited in the third aspect.
When the heating wire is heated, its hardness decreases. In the heater, since the discharge port side is hotter than the supply port side, the distance between the insulators arranged on the supply port side should be larger than the distance between the insulators arranged on the discharge port side. Thus, the heat conversion efficiency can be improved.

According to a fourth aspect of the present invention, specific means for providing an interval between the insulators in the above invention are specified, and the screw is inserted into at least two places in the axial direction of each insulator. A hole is provided, a long-axis screw is inserted through the hole, a spacer is interposed between the insulators, and a nut is screwed to fix the insulators at a predetermined interval.
The effect is the same as that of each invention described above.

  In the fifth aspect of the present invention, since the space portion is provided in at least one gas circulation hole located in the central portion, a temperature sensor can be inserted into the space portion and can be appropriately disposed at a desired position. Thus, it becomes possible to more appropriately sense and measure the maximum limit temperature (abnormal overheat temperature) of the wired heating wire. It is also possible to form a plurality of space portions and arrange the discharge temperature detection sensor, the abnormal overheat prevention detection sensor, and the like of the discharge gas together, for example, at the terminal on the supply port side of the heater.

  In the sixth aspect of the present invention, the wound heating wire wired in the gas flow hole of the insulator is fixed to the inner wall surface in the gas flow hole by a plurality of protrusions provided on the inner wall of the gas flow hole. Therefore, the heat exchange efficiency from the heating wire to the gas to be heated is good, the dust collected on the inner wall surface is not adversely affected, and the risk of disconnection is reduced.

It is a conceptual explanatory view of the heater for hot air generation concerning the present invention. It is an expanded sectional explanatory view of the portion of the heater storage object of one embodiment concerning the present invention. The insulator used in the above embodiment is illustrated, in which (A) is a front view and (B) is a partially cutaway side view. It is a graph which shows the hot air test result which performed the performance comparison which shows the relationship between the air volume and discharge temperature of the heater which concerns on this invention, and the conventional heater. It is a graph which shows the result of the pressure loss test with the heater which concerns on this invention, and the conventional heater. It is a perspective explanatory view of the conventional insulator. FIG. 7 is a conceptual explanatory diagram illustrating a conventional heater for generating hot air in which the insulator illustrated in FIG. 6 is disposed.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a conceptual explanatory diagram of a hot air generating heater according to the present invention.
The heater for generating hot air according to the present invention includes a substantially cylindrical heater housing 11 located on the front end side of the main body 10, a plurality of disc-shaped insulators 12 disposed inside the heater housing 11, and It consists of a nichrome wire (heating wire) 15 wired in a number of gas flow holes formed in the axial direction (gas flow direction) of the insulator 12, and a discharge port at the tip (right end in the figure) of the heater housing 11 20 is provided, and a supply port 22 for supplying blown gas from a blower or the like is provided in a lower part on the rear end side of the main body 10.

In this figure, three insulators 12 are used, and a space portion 13 having a predetermined interval is provided between the insulators 12.
Each insulator 12 is not shown in FIG. 1, but is fixed at a predetermined interval via a spacer with a long-axis bolt and a nut.
In this way, the plurality of insulators 12 are arranged and fixed in a row in a row substantially in the axial direction while maintaining an interval, and the positions of the plurality of gas flow holes formed in each insulator 12 are matched, A nichrome wire 15 as a heating wire is wired in the gas flow hole.

Both terminals of the nichrome wire are set so as to come to the rear end side of the heater housing 11.
Further, the plurality of insulators 12 that are fixed while maintaining an interval are fixed to the support plate on the rear end side of the main body 10 by the long-axis bolts 17.
Although this support plate is not shown in FIG. 1, the support plate is provided with a power source terminal of a nichrome wire, a terminal of a temperature detection sensor disposed at each position, and the like.

Blowing gas from a blower or the like is supplied from the supply port 22 through the pipe 23, guided to a large number of gas flow holes formed in the insulator 12, heated, and discharged from the discharge port 20 in the direction of arrow D. The
At this time, the blown gas is mixed and mixed in the spaces 13 provided between the insulators 12, the temperature of the blown gas is made uniform and the temperature is increased, and the amount of air passing through each gas circulation hole This contributes to the homogenization of heat and improves the efficiency of heat exchange from the nichrome wire.

FIG. 2 is an enlarged cross-sectional explanatory view of a heater housing portion of the heater according to the present invention.
The heater housing 11 is made of stainless steel and has a discharge port 20 at the tip (right end in the figure).
Inside the heater housing 11, a ring-shaped ceramic ring-shaped insulator 21 is disposed so as to overlap in the axial direction (gas flow direction). These are intended for heat insulation.

In this ring-shaped insulator 21, five insulators 12 for wiring the above-mentioned heating wires are arranged in a line substantially in parallel with each other at an interval.
The insulator 12 used here will be described in detail in the next figure. The outer diameter is about 72 mm, the thickness (width) is about 25 mm, and the distance between the insulators 12, that is, the width of the space 13 is about 13 mm. It is said.
These levers 12 are fixed to each other by a long-axis screw (bolt) 25, a nut 26, and a spacer 27 disposed between the levers 12.
The bolts 25 and the nuts 26 are fixed at two places on the periphery of the insulator 12.

  In this figure, the wiring of the nichrome wire that is a heating wire and the gas flow hole through which the nichrome wire is routed are omitted, but the nichrome wire is connected from the long screw (bolt) 30 that becomes the power terminal 31. This nichrome wire can be wired in the gas flow hole of each insulator 12, and both terminals of the nichrome wire are arranged at a portion of the support plate 35 located at the rear end portion of the heater housing 11. can do.

In this figure, two temperature sensors are clearly shown in the figure. That is, one discharge temperature sensor 36 is provided slightly on the discharge port side of the insulator 12 on the most discharge port side, and is supplied on the supply port side. An air temperature sensor 37 is provided.
In this embodiment, although not shown, a maximum temperature detection sensor for detecting the maximum temperature of the heater or a sensor for a hot starter is disposed at the center of the insulators arranged in a row.
The terminals of these temperature sensors can also be arranged on the surface of the support plate 35 opposite to the insulator.

A nichrome wire protective insulator 39 is arranged on the further discharge port side of the insulator 12 to which the nichrome wire is wired.
The protective insulator 39 is also made of a disk-shaped ceramic, and has a large number of gas flow holes having an inner diameter smaller than the gas flow holes of the insulator 12 in the axial direction.
Here, the role of the protective insulator 39 is to protect the nichrome wire when a rod-like object such as a driver bit is inserted from the discharge port.

FIG. 3 illustrates the insulator used in the above embodiment, in which (A) is a front view and (B) is a partially cutaway side view.
As can be seen from FIG. (A), a large number of gas flow holes 12 are formed in the axial direction (the front and back direction of the paper surface) of the insulator 12.
More specifically, three gas flow holes 12 are provided concentrically at the center, next seven, and on the outermost fourteen.

In the figure, reference numeral 14 denotes a screw insertion hole for a long-axis screw for fixing the insulators 12 to each other, and reference numeral 16 denotes a screw insertion hole for a long-axis bolt that becomes a terminal of a nichrome wire.
As can be seen from the above, the insulator 12 is fixed at the two screw insertion holes 14 at the outer peripheral edge of the insulator 12 while maintaining an interval.
Further, a long-axis screw is inserted into the three screw insertion holes 16 to form a nichrome wire terminal.

The three gas flow holes 12s in the center portion are provided with an extended space portion 12k in a part thereof, and a temperature sensor such as a thermocouple can be inserted into the extended space portion 12k to detect the temperature of each part of the heater. I am doing so.
For example, the already described discharge temperature detection sensor can be provided in the vicinity of the inside of the discharge port, and the maximum temperature detection sensor or the temperature detection sensor for the hot starter can be provided at an intermediate portion of the insulators arranged in line. Can be wired together on the support plate on the supply port side.

Each gas flow hole 12 is provided with four ridges 12t in the gas flow direction, and these four ridges 12t support the nichrome wire wound in a spiral shape. The structure which does not contact the inner wall surface of is adopted.
Thereby, ventilation air distribute | circulates inside and outside the spiral of a nichrome wire, and heat exchange efficiency is improved.
The cross section of the right half of the figure (B) is the gas flow hole 12 arranged in the innermost part of the center part of the front view, the screw insertion hole 16 arranged in the middle part, and the outermost part. The cross-sectional portion of the gas flow hole 12 is shown as a representative of the respective portions arranged concentrically.

  Here, in the gas flow hole 12, the maximum inner diameter (the part other than the projecting part) of the three gas flow holes 12s provided in the most central part and the seven gas flow holes 12c provided in the intermediate part on the outer side thereof. The innermost gas) is about 10.0 mm, and the outermost gas, that is, the outermost gas, ie, the outermost side gas circulation hole 12p has a maximum inner diameter (inner diameter of a portion other than the protrusion) of about 9.6 mm. The inner diameter of the flow hole 12p is slightly small, and is formed to be about 4% smaller in proportion.

The reason for this is to improve the heat exchange efficiency to the blown gas, as already described in the effect of the invention.
That is, in the insulators arranged in a row, when the heating wire is heated, the heat escapes to the outside, so that the central portion is about 20 ° C. to 30 degrees higher than the peripheral portion. Therefore, in order to make the heat exchange more efficient, the maximum inner diameter of the gas circulation holes 12s and 12c provided in the central part of the insulator is slightly smaller than the maximum inner diameter of the gas circulation hole 12p provided in the outer peripheral part. Numerically, it was designed to be about 4% larger and designed to increase the air volume of the gas circulation hole in the central part.

As described above, the gas flow holes in the central portion of the insulator have a larger maximum inner diameter, and the maximum inner diameter of the outer peripheral portion is slightly smaller. Therefore, the gas flow holes 12s and 12c in the central portion are formed. The height of the protruding portion 12t provided on the inner wall is formed higher than the height of the protruding portion 12t provided on the inner wall of the gas flow hole 12p in the outer peripheral portion. This is in order to adapt to the outer diameter of the nichrome wire spiral.
The insulator used in the present invention is made of silica-alumina ceramics.

FIG. 4 is a graph showing hot air test results in which a performance comparison showing the relationship between the air volume and the discharge temperature between the heater according to the present invention and the conventional heater described in Patent Document 2 is performed.
In this graph, the result of the heater of the present invention is indicated by a thick solid line, and the conventional one is indicated by a thin solid line.
As will be understood, in the heater according to the present invention, the thick line comes to the upper right side, and the highest discharge temperature can be obtained at the same air volume.

FIG. 5 is a graph showing the results of a pressure loss test between the heater according to the present invention and the conventional heater described in Patent Document 2.
Also in this graph, the result of the heater according to the present invention is shown by a thick solid line, and the conventional one is shown by a thin solid line.
As will be understood from the above, in the present invention, the thick line comes to the rightmost side, and it can be clearly understood that the pressure loss is always small at the same air volume, and it becomes clear that heat exchange is performed efficiently.

As mentioned above, although embodiment of this invention was described, in this invention, various design changes are possible as follows.
In the present invention, the arrangement of the insulators used in the heater is the most important technical matter, and the disk-shaped insulators are arranged in a row at a predetermined interval substantially parallel to the axial direction. The size of the space is very important.

Since the insulator itself can be manufactured by changing its outer diameter and thickness as appropriate according to the capacity of the heater, the specific size of the insulator and the width of the space are set numerically. And cannot be limited.
Therefore, in the present invention, repeated experiments using various sizes of insulators were conducted, and a predetermined relative ratio was derived through trial and error for the axial thickness of the insulators and the distance between the insulators. As a result, it has been found that by setting the distance between the insulators to a range corresponding to approximately 1/2 to approximately 2 of the insulator thickness, the range having the highest thermal efficiency is found.

As an example, as shown in the above embodiment, when the outer diameter is approximately 72 mm, the thickness is approximately 25 mm, and the distance between the insulators is approximately 13 mm.
Here, the outer diameter is almost the same as that of the insulator and the thickness can be very thin. For example, when the thickness is about 10 mm, the distance between the insulators is almost twice the thickness. Even when it was carried out at about 20 mm, the efficiency was within a good range.
Therefore, in claim 1, the distance between the insulators is specified in the range of about 1/2 to about twice the thickness of the insulator using the distance between the insulators.

Next, regarding the technical matter specified in claim 2, in the above-described embodiment, the maximum inner diameter of the gas flow hole located in the central portion of the insulator is about 4 times larger than the maximum inner diameter of the gas flow hole located in the outer peripheral portion. The numerical value of 4% is merely an example, and it may be designed to be slightly larger, for example, about 6%.
In addition, regarding the technical matter specified in claim 3, the distance between the insulators gradually decreases from the supply port side toward the discharge port side, and the interval distance, that is, the longitudinal distance of the space portion is also the same as that of the insulator. The design can be freely changed as appropriate within a range of approximately ½ to 2 thicknesses.

The number of gas flow holes formed in the insulator can be designed as appropriate, but the number is naturally limited when the inner diameter of the gas flow holes is determined.
In the above embodiment, four protrusions provided on the inner wall of the gas flow hole are provided in the gas flow direction. However, the number of the protrusions may be three. These protrusions support the nichrome wire wound in a spiral shape from the outside. If at least three nichrome wires are provided, the nichrome wire is held at a certain distance from the inner wall surface of the gas flow hole. Because it can be done.

There may be at least two long-axis screws or the like for fixing the insulator while maintaining a predetermined interval.
In the above embodiment, three expansion spaces provided in the gas flow holes located at the center of each insulator for sensor insertion are provided in the above-described embodiment, but may be provided in at least one gas flow hole. Depending on the number, temperature detection at a plurality of locations in the heater can be performed.
The number of insulators used for the heater can be appropriately determined in consideration of the heater capacity.

The supply port of the supply gas supplied from the blower or the like can be provided in any part on the rear end side of the main body part. In the above embodiment, the supply port is provided in the lower part of the rear end of the main body part. It can also be provided above, or can be provided on the rear end surface of the main body.
You may implement by providing a cylindrical-shaped heat insulation cover in the outer periphery of the trunk | drum part of a heater accommodating body.
As described above, the present invention uses a plurality of disc-shaped insulators without holding the heating wire, and maintains them at a predetermined interval, thereby fixing them at least as much as conventional heaters for generating hot air. We were able to provide something with performance.

DESCRIPTION OF SYMBOLS 10 Main body part 11 Heater storage body 12g insulator 12, 12s, 12c, 12p Gas flow hole 12k Space part (of gas flow hole)
12t protrusion (of gas flow hole)
13 Space part 14, 16 Screw insertion hole 15 Nichrome wire (heating wire)
17, 30 Long shaft screw 20 Discharge port 22 Supply port 25 Long shaft screw 26 Nut 27 Spacer 29 Protection lever 31 Power supply terminal 36, 37 Temperature sensor

Claims (6)

An insulator (12g) is provided inside a substantially cylindrical heater housing (11) provided with a gas supply port (22) at one end and a discharge port (20) at the other end. 12g) a large number of gas flow holes (12) provided with heating wires (15), and the blowing gas supplied from a blower or the like through the supply port (22) is the insulator (12g) In the hot air generating heater that heats the gas through the gas flow holes (12) and discharges hot hot air from the discharge port (20).
The insulator (12g) is formed from a plurality of disk-shaped members having a predetermined thickness, and the gas flow holes (12) are provided in the axial direction thereof.
These multiple insulators (12g) are arranged in a row in the air blowing direction with a spacing approximately parallel to each other, and the spacing is set to a distance of about 1/2 to about two of the thickness of the insulator (12g). A heater for generating hot air.   In the gas flow hole (12) of each insulator (12g), the maximum inner diameter of the gas flow hole (12s, 12c) located in the central part is slightly smaller than the maximum inner diameter of the gas flow hole (12p) located in the outer peripheral part. The heater for generating hot air according to claim 1, wherein the heater is large.   The heater for generating hot air according to claim 1 or 2, wherein the distance between the insulators (12g) is gradually reduced from the supply port (22) side toward the discharge port (20) side.   At least two screw insertion holes (14) are provided at appropriate positions in the axial direction of the respective levers (12g), and the long-axis screws (25) are inserted into these screw insertion holes (14). The hot air according to any one of claims 1 to 3, wherein a nut (26) is screwed with a spacer (27) interposed therebetween, and each insulator (12g) is fixed at a predetermined interval. Generation heater.   A space (12k) is formed through which a temperature sensor can be inserted into at least one of the gas flow holes (12s) drilled in the central portion of each insulator (12g) where the heating wire (15) is disposed. The heater for generating hot air according to any one of claims 1 to 4, wherein the heater is used.   On the inner wall of the gas flow hole (12) of each insulator (12g) where the heating wire (15) is disposed, a plurality of protrusions (12t) supporting the heating wire (15) are provided in the gas flow direction, The hot air according to any one of claims 1 to 5, wherein the wound heating wire (15) can be supported in the gas flow hole (12) while maintaining a distance from the inner wall thereof. Generation heater.