JP2018066296A - Heat-resistance electric blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat resistance blower which can suck a high-temperature gas having a temperature up to about 770°C by using a general stainless steel material.SOLUTION: An electric rotating drive machine is fixed to one side face of a casing 11 in which an impeller 20 is arranged, the impeller 20 is fixed to a rotating drive shaft of the rotating drive machine, a suction port for sucking a high-temperature gas is formed in a direction of the rotating drive shaft 32 of the impeller 20 at a side opposite to the rotating drive machine, and a discharge port 13 is formed in a substantially-tangential direction of a rotation trajectory of the impeller 20 in the casing 11. The impeller 20 is composed of a cylindrical body part 21 having a bearing part therein, and a plurality of blade parts 22 which are arranged at an external peripheral part of the cylindrical body part 21. Each of the blade parts 22 is formed of two pieces of plate-shaped bodies 22p, tips of the blades are welded to form a substantial isosceles triangle in a side face view, and two base end parts are fixed to the external peripheral part of the cylindrical body part 21.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat-resistant electric blower capable of sucking the high temperature hot air and discharging the high temperature hot air in order to reuse or circulate the high temperature hot air discharged from a hot air blower or the like. The present invention relates to a heat-resistant electric blower improved so that the temperature of gas can be used in a higher temperature range.

Examples of conventional heat-resistant blowers include those described in the following patent documents.
What is described in Patent Document 1 below relates to an impeller for high-temperature gas blowing, a high-temperature gas blower equipped with the impeller, and a hot-air circulating furnace equipped with the high-temperature gas blower, and has high-temperature heat resistance. It is another object of the present invention to provide a device that can be driven at a high rotational speed.

The blade is composed of an oxide dispersion strengthened alloy by a mechanical alloy method in which fine particles of a high melting point metal oxide are contained in a dispersed state in a nickel-based alloy matrix, that is, an austenite matrix. Thus, the mechanical strength can be maintained, and the oxide dispersion strengthened alloy by the mechanical alloy method is stable in strength up to a high temperature.
The impeller can maintain a sufficient strength even at a high temperature of, for example, 1200 ° C. and can be rotated at a high speed. Therefore, even if the circulation fan using the impeller is small, a high blowing capacity can be obtained. The floating conveyor using can also be made small.

  The high-temperature gas blower fan described in Patent Document 2 below does not deform the boss in a short period of time even if it is rotated at high speed under high temperature use conditions, improves durability, reduces maintenance costs, and allows high speed rotation. An object is to maintain the required air volume.

The structure consists of a boss composed of an oxide dispersion strengthened alloy containing 0.1 to 2% by weight of high melting point metal oxide fine particles in a dispersed state and a plurality of blades, and the boss is formed in a solid cylindrical shape. In addition, fitting grooves are formed on the outer periphery at regular intervals, and the blades are fitted into the fitting grooves.
Further, a rotating shaft made of heat-resistant steel is fixed to one end of the boss by welding, the rotating shaft is rotatably supported by a bearing, and the rotating shaft is connected to a rotation drive source.

  In the above conventional one, the problem is solved by using a special alloy as a blade part or a boss, but it is a problem in the present invention not to use such a special alloy. The following problems exist when using steel.

Usually, most general blowers are used in a normal temperature range.
Further, some of the blowers are sold by adding a little modification to a general standard type so that the use environment of the impeller can be used even in a high temperature region.
The general blower referred to here is a shell-type blower, commonly called a fan, and a fan capable of sucking high-temperature gas is also called a heat-resistant electric blower or a heat-resistant fan.

In the case of the heat-resistant electric blower, most of the intake gas temperatures are 0 to 165 ° C, 230 ° C, and 260 ° C.
If the suction gas temperature is higher than this, for example, 350 ° C, 500 ° C, 700 ° C, 1000 ° C, the structure, material, etc. are changed according to the difference in these temperatures, and special orders are received. Will be very expensive.

The reason why the fans used in the high temperature range are expensive is as follows.
In the case of a general-purpose blower, the impeller is designed with an emphasis on the efficiency of the blower, is mass-produced, has a simple structure, and is manufactured using inexpensive materials.
However, if the fans related to these general-purpose products are used by sucking high-temperature gas as they are, cracks will occur from the welded part of the impeller, and the rotational balance (dynamic balance) of the impeller will be lost, causing the fan to vibrate abnormally. The bearing (bearing) of the blower is damaged, and finally the impeller is damaged in a short time.

Therefore, it is necessary to design in consideration of the mechanical characteristics of the material to be used while leaving the blowing performance (efficiency).
Therefore, as a blower that can withstand the inhalation of high-temperature gas, it is necessary to manufacture the impeller itself robustly and firmly, and as a result, the volume and weight become large.

The reason is that it is necessary to manufacture in consideration of thermal stress.
In other words, when the impeller stops and cools, residual stress remains and is not destroyed by the residual stress, so that the above-described robust and sturdy structure must be obtained.

JP-A-7-119692 JP 2003-13882 A

  Therefore, as described above, in the above-mentioned conventional one, the problem was solved by using a special alloy as a blade part or a boss. However, in the present invention, a general stainless steel material having heat resistance is used. Further, for example, it is an object to make it possible to suck in high-temperature gas by structurally improving the blower using an austenitic stainless steel material such as SUS304, SUS309S, SUS310S, or SUS316. .

  In addition, in the present invention, it is an object of the present invention to provide a small and lightweight blower that allows the intake gas temperature up to 770 ° C. by using SUS304 or SUS309S of the above-mentioned materials.

  Therefore, first, as a result of experiments at various hot air temperatures, the plate thickness of the blade portion was set to 1 mm with a conventional fan of a general shape (an impeller having a plurality of blade portions made of a single plate). When there is no temperature difference between the upper and lower surfaces, the whole thermally expands at a high temperature range, and when it returns to room temperature, it thermally contracts. Although the thermal strain is large, no thermal stress is produced and no residual stress remains.

  However, when a gas in a high temperature range of about 300 ° C. to 500 ° C. or higher is sucked, in the case of an impeller having such a general shape, if the temperature of the impeller is increased when the impeller is heated, Since the tensile strength is reduced, the maximum bending torque is generated at the installation site of the impeller while the impeller is rotating, causing thermal deformation, and if the elastic limit of the metal is exceeded, permanent deformation is generated. The impeller becomes unbalanced during rotation. When an imbalance occurs in the impeller, when it rotates, vibration and noise are generated by centrifugal force, and finally it is damaged.

Therefore, the material softens due to the heat and bending torque is applied to it, so if you want to weld a reinforcing material to the part that is easy to bend or increase the thickness of the material to increase the strength, actually In the welding process, residual stress remains because heat is applied. For this purpose, all the parts may be welded at the same time, but this is not practical and difficult.
However, something that has been reinforced somehow takes labor, increases the mass, and is expensive. In order to rotate the heavy one, wasteful energy will be used, and this will go backwards from the viewpoint of energy saving.

The steel material shrinks in volume when heated to transform from pearlite to austenite. In other words, it is necessary to create a shape that can be used in a harsh environment where the blade portion repeatedly expands and contracts due to temperature changes.
Therefore, an object of the present invention is to produce an impeller that can be used even in a high temperature region in consideration of the characteristics of the steel material.

  In other words, in consideration of the characteristics of metal, to manufacture an impeller that can be used in a high temperature range, it is possible to manufacture an inexpensive product with good performance, which is made of a commercially available material that is free from residual stress and has good productivity. It is an object of the present invention to determine what shape is required for manufacturing.

  In order to solve the above-mentioned problem, the first one of the present invention is to fix an electric rotary drive machine on one side surface of a casing in which an impeller is disposed, and to the rotary drive shaft of the rotary drive machine, the blades A car is fixed, a suction port for sucking high-temperature gas is provided in the direction of the rotational drive shaft of the impeller on the side opposite to the rotary drive machine, and a discharge port is provided in a substantially tangential direction of the rotational trajectory of the impeller in the casing. In the heat-resistant electric blower, the impeller includes a cylindrical body portion having a bearing portion therein and a plurality of blade portions provided on an outer peripheral portion of the cylindrical body portion, and each of the blade portions is formed in two plate shapes. The heat-resistant electric blower is characterized in that it is formed from a body, and its distal end portion is joined and fixed to form a substantially isosceles triangle in a side view and two base end portions are fixed to the outer peripheral portion of the cylindrical body portion.

  According to a second aspect of the present invention, in the first aspect, the bearing portion provided inside the cylindrical body portion is a boss receiver made of a disk-shaped plate material that closes the opening portion on the suction port side of the cylindrical body portion. The heat-resistant electric blower is characterized in that a boss portion protruding in the direction of the rotational drive shaft is provided inside the portion, and the bearing portion is provided at a substantially central portion of the boss portion.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the heat-resistant electric blower is characterized in that at least one cooling fan is provided on a rotational drive shaft between the rotational drive unit and the impeller. It is.

  According to a fourth aspect of the present invention, in the above third aspect, the rotary driving machine is fixed to one side surface of the casing via a bracket, the cooling fan is disposed inside the bracket, and the bracket Is a heat-resistant electric blower characterized in that a large number of through holes are provided.

  A fifth aspect of the present invention is the heat-resistant electric blower according to the fourth aspect, wherein two or more cooling fans are provided on the rotational drive shaft of the rotational drive unit.

  A sixth aspect of the present invention is the heat-resistant electric blower according to each of the above-described inventions, further comprising a heat insulating material surrounding all or part of both side surfaces and peripheral side surfaces of the casing.

  A seventh aspect of the present invention is the heat-resistant electric blower according to each of the above-described inventions, wherein a filter member for removing dust is provided at the opening of the suction port.

  According to an eighth aspect of the present invention, there is provided a heat-resistant electric blower according to any one of the above-described inventions, wherein an elastic flexible joint for connecting to a pipe is connected to the suction port and the discharge port.

  In the first aspect of the present invention, an electric rotary drive is fixed to one side surface of a casing in which an impeller is disposed, and the impeller is fixed to a rotary drive shaft of the rotary drive, and the rotation In the heat-resistant electric blower provided with a suction port for supplying high-temperature gas in the rotational drive shaft direction of the impeller on the side opposite to the drive machine, and provided with a discharge port in a substantially tangential direction of the rotation trajectory of the impeller in the casing, The impeller includes a cylindrical body portion having a bearing portion therein and a plurality of blade portions provided on the outer peripheral portion of the cylindrical body portion, and each of the blade portions is formed of two plate-like bodies, and the tip thereof The two base end portions are fixed to the outer peripheral portion of the cylindrical body portion as a substantially isosceles triangle when viewed from the side by heating and cooling by the shape of the blade portion of the approximately isosceles triangle when viewed from the side. Residual stress is unlikely to occur due to repeated use of It was a Jo.

  In this way, by using two thin plates made of stainless steel, for example, and assembling them into a triangle, the strength of the blades and impellers is increased, and the residual stress is less likely to remain. Furthermore, the use of a thin material leads to saving of material.

  In addition, the “mountain” portion at the tip when assembled to the triangle can be fixed by welding, riveting, screwing, or the like, while the two base ends are fixed by welding, screwing, plug-in type, or the like. The fixing method can be determined in consideration of the hot air temperature to be sucked.

  Thereby, even if the suction gas temperature is about 700 ° C. (up to 770 ° C. in the following embodiment), it can be used without any problem by repeating the expansion of the metal by heating and the contraction at normal temperature after use. A heat-resistant electric blower could be provided.

In the second aspect of the present invention, the bearing portion provided inside the cylindrical body portion is more specifically specified.
That is, the bearing portion provided inside the cylindrical body portion is provided with a boss portion that protrudes in the rotational drive shaft direction inside the disk-shaped plate material that covers the opening on the suction port side of the cylindrical body portion. The bearing portion is provided at substantially the center portion of.

  In the third aspect of the present invention, at least one cooling fan is provided on the rotary shaft between the rotary drive machine and the impeller, and the bearing portion is prevented from being damaged due to high temperature of the rotary drive shaft. It has taken measures to do.

  According to a fourth aspect of the present invention, the cooling fan is mounted more specifically. That is, the rotary drive is fixed to one side surface of the casing via a bracket, and the cooling fan is mounted. The bracket is provided inside the bracket, and a plurality of through holes are provided in the bracket, and the intake and discharge of the outside air is achieved by the plurality of through holes to improve the cooling efficiency.

  According to a fifth aspect of the present invention, two or more cooling fans are provided on the rotational drive shaft. The same effect as the fourth invention is intended.

  In the sixth aspect of the present invention, there is provided a heat insulating material surrounding all or a part of both side surfaces and peripheral side surfaces of the casing, and the present invention is different from the conventional blower described above. This is because the heat-resistant blower according to the above is not arranged in the heating furnace, but reuses and circulates the hot gas and is used in various factories using various pipes.

The seventh aspect of the present invention is characterized in that a filter portion is provided at an inlet portion of a suction port of a blower that sucks high-temperature gas.
Of course, products without a filter are also produced, but dust and the like contained in the sucked hot gas are removed to supply clean hot gas in the next step.

  In the eighth aspect of the present invention, in order to connect a pipe to the suction port or the discharge port, a flexible joint that can be expanded and contracted is connected in advance. In order to prevent this, if the piping expands at the inlet and outlet of the blower on the user side, if the piping is thermally expanded, a considerable deformation force is applied to the blower depending on the method of fixing the piping. Optional parts.

It is a front see-through | perspective conceptual diagram of one Embodiment which concerns on the heat-resistant electric blower of this invention. It is right side see-through explanatory drawing of the heat-resistant fan concerning the embodiment shown in the above-mentioned FIG. FIG. 2 is a left side perspective explanatory view of the embodiment shown in FIG. 1 and shows a casing and an impeller portion. It is a left view of the impeller which concerns on the said embodiment. FIG. 5 is an explanatory front perspective view of the impeller shown in FIG. 4, in which illustration of the two blade portions in front is omitted. It is a graph which shows a vibration test result, The (A) shows the result of the said embodiment (triangular blade type impeller) based on this invention, The (B) is the conventional heat-resistant electric blower (conventional type impeller). The results are shown.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a front perspective view of an embodiment of the heat-resistant electric blower of the present invention, as viewed from the discharge port side.
The heat-resistant electric blower 10 according to the present invention (hereinafter simply referred to as “blower 10”) is electrically driven via a bracket 14 on one side surface (right side surface in FIG. 1) of the casing 11 in which the impeller 20 is disposed. A rotary drive machine (electric motor) 30 (hereinafter also simply referred to as “rotary drive machine 30” or “electric motor”) is attached.

A suction port 12 for sucking high-temperature gas is provided at a substantially central portion of the left side surface of the casing 11 in the drawing, and this high-temperature gas is substantially tangential to the rotation locus of the tip of the blade portion 22 of the impeller 20. It is discharged to the outside from the provided discharge port 13.
In this embodiment, the suction port 12 and the discharge port 13 are provided with a flexible joint F that can be expanded and contracted. These are provided in order to prevent the pipes to be connected from being affected by thermal expansion.

  The impeller 20 is fixed to the tip end portion of the rotary drive shaft 32 of the rotary drive machine 30 attached to the right side surface of the casing 11 in the figure. Although the configuration of the impeller 20 itself will be described later, the impeller 20 includes a cylindrical portion 21 located at the center thereof, and a plurality of vane portions 22 fixed to the outer peripheral portion of the cylindrical portion 21. Consists of.

  A disc-shaped boss receiving portion 23 covering the left end opening of the cylindrical portion 21 is provided on the suction port 12 side provided on the left side of the cylindrical portion 21 in the figure, and the boss portion 24 is provided on the boss receiving portion 23. Can be fixed.

A hole portion into which the distal end portion of the rotation drive shaft 32 of the rotary drive machine 30 is fitted is provided at a substantially central portion of the boss portion 24, and the distal end portion of the rotation drive shaft 32 is fitted into the hole portion to be screwed or the like. It is fixed by.
As a result, the impeller 20 is fixed to the distal end portion of the rotary drive shaft 32 of the rotary drive machine 30.

A side plate 15 for interposing a heat insulating material is provided between the bracket 14 and the casing 11, and the side plate 15 is fixed to the side surface of the casing 11 so as to be separated from the side surface of the casing 11 by a predetermined distance. Has been.
A heat insulating material 40 is disposed between the side plate 15 and the casing 11, and the heat insulating material 40 covers the other side surface and outer peripheral surface of the other casing 11 (except for the suction port 12 and the discharge port 13). It is provided as follows.
The heat insulating material 40 is provided so as to cover only the lower portion except for the upper portion of the casing 11, but can be formed so as to cover the whole.

A through hole through which the rotation drive shaft 32 passes is provided in the substantially central portion of the side plate on the right side of the side plate 15 and the casing 11, and the inner periphery of the through hole in the right side portion of the latter casing 11. A sealing material 16 is provided in the part.
Further, cooling fans 34 and 35 are fixed to portions where the rotation drive shaft 32 penetrates the bracket 14 portion.

  When the rotation drive shaft 32 rotates, the cooling fans 34 and 35 fixed to the rotation drive shaft 32 cool the rotation drive shaft 32, and from a large number of through holes 36, 36,. Outside air is introduced and discharged, and cooling is performed. (In FIG. 1, since this through hole 36 overlaps with the cooling fans 34 and 35 and becomes unclear, only a part thereof is shown.)

The bracket 14 can be provided with a leg portion 39 for supporting the heat-resistant blower 10, and the leg portion 39 supports the heat-resistant blower 10 according to the present invention and is fixed at an appropriate position so that the height can be adjusted. It becomes.
As described above, the heat-resistant blower 10 according to the present invention can be manufactured in a small size as in the conventional blower.

FIG. 2 is a right side perspective explanatory view of the heat-resistant blower according to the embodiment shown in FIG.
From this explanatory view, the side surface shape of the casing 11, the side surface shape of the side plate 15, and the side surface shape of the bracket 14 can be seen.

As is well understood from this figure, the discharge port 13 is provided in a substantially tangential direction of the rotation trajectory of the tip of the blade portion of the impeller inside the casing 11 having a substantially circular shape when viewed from the side.
A flexible joint F is provided at the discharge port 13.

The side view shape of the bracket 14 is substantially rectangular, has a truncated pyramid shape, and is fixed to the side plate 15.
The bracket 14 is provided with a large number of through holes 36 over the entire circumference of its side surface.

  The side plate 15 has a shape obtained by cutting off a substantially rectangular corner, and is provided so as to cover the side portion of the casing 11. The side plate 15 is provided between the side plate 15 and the casing 11 and other parts of the casing 11. In this configuration, the heat insulating material can cover the side surface and the peripheral surface.

FIG. 3 is a left side perspective explanatory view of FIG. 1 and illustrates the casing and impeller portions.
From this drawing, the shape of the impeller 20 can be seen.
The impeller 20 includes a cylindrical cylindrical portion 21 at the center thereof and six blade portions 22 fixed to the outer periphery of the cylindrical portion 21, and a boss is provided on the front end face of the cylindrical portion 21. A receiving portion 23 is provided, and a boss portion into which the rotational drive shaft is fitted is fixed to the boss receiving portion 23.

  The blade portion 22 of the impeller 20 is composed of two plate-like bodies 22p and 22p, which will be described later, and these plate-like bodies 22p and 22p are combined in a substantially isosceles triangle in a side view, that is, a tip portion thereof. Are welded by fitting the two base end portions to the outer peripheral portion of the cylindrical portion 21.

The welding of the tip portion may be riveted or screwed. On the other hand, the two base end portions can also be fixed by welding, screwing or insertion, and the fixing method can be selected in consideration of the intake gas temperature.
The said impeller 20 and the blade | wing part 22 are further demonstrated with the following figure.

FIG. 4 is a left side view of the impeller according to the embodiment.
FIG. 5 is a front perspective explanatory view of the impeller shown in FIG. 4, in which the illustration of the two front blade portions is omitted.

As can be seen from both the drawings, the blade portion 22 is composed of two plate-like bodies 22p and 22p made of stainless steel material of SUS309S, both of which are welded at the tip portion 22y, and the base end portion is a cylindrical body. It is fixed to the outer peripheral part of the part 21.
The base end can be fixed by welding, screwing, insertion, or the like.

As described above, the six blade portions 22 having a substantially isosceles triangle in a side view are firmly fixed to the outer peripheral portion of the cylindrical portion 21 and can be manufactured from a thin steel plate.
In this embodiment, as the outer peripheral shape of each plate-like body 22p, a lateral width in the horizontal direction in the figure is wide at the tip portion.

The material of the impeller 20, the casing 11, the bracket 14, and the side plate 15 is made of stainless steel such as SUS309S or SUS304.
The bracket 14 may use an iron plate, and the side plate 15 may use SUS304 or an iron plate.

  Moreover, the plate-like body 22p which comprises the blade | wing part 22 uses a thing with a plate pressure of 1 mm, the apex angle of the substantially isosceles triangle of the side view of the blade | wing part 22 is set to 14 to 15 degree | times, The diameter of the impeller 20 is about 290 mm.

  The screw holes 22s appearing in the plate-like body 22P of the blade portion 22 in FIG. 5 are provided for screwing a weight as a balancer appropriately at this location. This weight is for adjusting the rotational balance of the impeller, but can also be manufactured without providing it.

Further, it is extremely desirable to dispose a heat insulating material between the outer peripheral surface of the boss portion 24 and the inner peripheral surface of the cylindrical body portion 21 shown in FIG.
The heat insulating material includes the heat insulating material 40 disposed around the casing, and the material thereof is made of various materials such as glass wool, rock wool, ceramic fiber, or a composite of ceramic fiber and glass fiber. Can be used.

Finally, a hot air is circulated with respect to the heat-resistant blower 10 to perform a vibration test, and the test results are shown below.
In this vibration test, the motor vibration value at a predetermined temperature was measured when the temperature of the suction gas was raised from room temperature to 770 ° C. and then cooled to room temperature.
FIG. 6 is a graph showing the results of the vibration test, in which (A) shows the results of the above-described embodiment (triangular blade type impeller) according to the present invention, and (B) shows a conventional heat-resistant electric blower. The result of (conventional impeller) is shown.

This conventional heat-resistant blower is an impeller in which a plurality of blade portions composed of one plate are radially fixed to a cylindrical portion (having a bearing portion at the center).
Table 1 below shows the test results in a table.

  As can be seen from FIG. 6A and Table 1 above, in the embodiment of the present invention, the vibration value is 13 μm at the normal temperature at the start, and then the suction gas temperature is increased to 13 μm at 500 ° C. and 600 ° C. 15 μm, 18 μm at 700 ° C., 18 μm at 770 ° C., and then 14 μm when the suction gas temperature is lowered to room temperature, and the vibration values at the first and last room temperature are almost the same.

  On the other hand, in the case of a conventional heat-resistant blower, the vibration value is 11 μm at the first normal temperature, 75 μm at 500 ° C., 150 μm at 700 ° C., and then returns to the vibration value at the first normal temperature of 22 μm when lowered to normal temperature. There was no.

Thus, in the heat-resistant blower according to the present invention, it is shown that the hot air blowing up to about 770 ° C. is performed and the hot air is blown back to the original state after use. It was found that almost no residual stress remained.
On the other hand, in the case of the conventional example, when the temperature exceeds 500 ° C., the vibration is just an abnormal vibration, and the vibration does not return to the initial value and the residual stress remains even if the vibration is returned to the normal temperature after that. I was able to judge.

As mentioned above, although embodiment of this invention was described, various design changes are possible as follows in this invention.
The size, shape, and the like of each of the constituent members according to the present invention can be appropriately changed as necessary.

  Especially, as for the shape of the impeller blade part, it is the point of the present invention that its side view shape is a substantially isosceles triangle, and by adopting this triangular shape, the resistance against residual stress is maintained. In the above embodiment, the apex angle is approximately 14 degrees to 15 degrees, but the apex angle may be slightly different.

Moreover, you may provide a protrusion in the base end part of the two plate-shaped bodies which comprise a blade | wing part, and fit the protrusion provided in the base end part in the hole provided in the cylinder part, and then It can also be formed by welding.
It is desirable that welding of the upper end portion of the plate-like body or welding of the projecting piece should be performed with a firm and strong welding. The welded portion may be riveted or screwed.

The number of blades can be changed as appropriate except for six.
It is also possible to provide at least one cooling fan or two or more cooling fans.
The shape of the bracket can also be circular when viewed from the side. That is, it can also be a substantially truncated cone shape.

In the above embodiment, two cooling fans are provided, and the functions thereof are as follows.
The casing side of the blower is hot by several hundred degrees, and the electric motor has heat.
In the latter electric motor, wind is generated by a fan behind the electric motor to cool the motor so that the surface temperature of the motor does not rise above 80 ° C.

Therefore, it is convenient if the interval between the casing side and the motor is increased, but then it is necessary to lengthen the rotational drive shaft of the motor.
This leads to an increase in cost, and becomes a completely special order product, resulting in a motor that does not meet international standards.

  Therefore, the two cooling fans are provided, and the function of the cooling fan on the casing side of the blower plays a role of preventing heat radiation from the casing and the shaft and conduction heat from the shaft from coming to the motor side.

On the other hand, the function of the cooling fan located on the motor side further cools the shaft and the bearing on the motor side. As a result, the temperature of the rotary drive shaft near the motor is about 47 ° C. (room temperature 32 ° C.).
By such an effect, the maintenance period of the bearing becomes longer, which greatly contributes to energy saving.

A filter member made of a frame body in which a net or a net-like filter is stretched may be added to the opening of the suction port for sucking in hot gas.
If the frame has the same size and the same shape as the frame portion of the suction port according to the above embodiment, it can be easily mounted with a screw or the like.
Although this filter member can also use the thing of various forms, it needs to have a heat-resistant effect.

  A stainless steel material having heat resistance can also be used as the material of the flexible joint that can be expanded and contracted added to the suction port and the discharge port, but the length and the like can be freely set.

  As described above, in the present invention, by using a conventional general stainless steel material, the configuration of the blade portion of the impeller is a substantially isosceles triangle when viewed from the side, so that the residual stress is minimized and permanent use is possible. It has been possible to propose a small heat-resistant electric blower that can be used.

DESCRIPTION OF SYMBOLS 10 Heat-resistant electric blower 11 Casing 12 Suction port 13 Discharge port 14 Bracket 15 Side plate 16 Sealing material 20 Impeller 21 Cylindrical body part 22 Blade part 22p Plate-like body 22y Tip part 23 Boss receiving part 24 Boss part 30 Electric rotary drive machine 32 Rotation drive shaft 34, 35 Cooling fan 36 Through hole 39 Leg 40 Heat insulating material

Claims (8)

An electric rotary drive is fixed to one side surface of a casing in which an impeller is disposed, and the impeller is fixed to a rotary drive shaft of the rotary drive, and the impeller on the side opposite to the rotary drive is fixed. In the heat-resistant electric blower provided with a suction port for sucking high-temperature gas in the rotational drive shaft direction, and provided with a discharge port in a substantially tangential direction of the rotation trajectory of the impeller in the casing,
The impeller (20) comprises a cylindrical body portion (21) having a bearing portion therein and a plurality of blade portions (22) provided on the outer peripheral portion of the cylindrical body portion (21),
Each of the blade portions (22) is formed of two plate-like bodies (22p, 22p), and the distal end portions thereof are joined and fixed to form substantially isosceles triangles in a side view, and the two base end portions are the cylindrical body portions ( A heat-resistant electric blower characterized by being fixed to the outer peripheral portion of 21).   The bearing portion provided inside the cylindrical body portion (21) is a rotational drive shaft inside a boss receiving portion (23) made of a disk-shaped plate material that closes the opening on the suction port side of the cylindrical body portion (21). The heat-resistant electric blower according to claim 1, wherein a boss portion (24) projecting in the (32) direction is provided, and the bearing portion is provided at a substantially central portion of the boss portion (24).   The at least 1 cooling fan (34, 35) was provided in the rotational drive shaft (32) between the said rotational drive machine (30) and an impeller (20), The Claim 1 or 2 characterized by the above-mentioned. Heat-resistant electric blower.   The rotary drive (30) is fixed to one side surface of the casing (11) via a bracket (14), and the cooling fans (34, 35) are disposed inside the bracket (14), The heat-resistant electric blower according to claim 3, wherein the bracket (14) is provided with a plurality of through holes (36, 36, ...).   The heat-resistant electric blower according to claim 4, wherein two or more cooling fans (34, 35) are provided on the rotation drive shaft (32) of the rotation drive machine (30).   The heat-resistant electric blower according to any one of claims 1 to 5, further comprising a heat insulating material (40) surrounding all or part of both side surfaces and peripheral side surfaces of the casing (11). .   The heat-resistant electric blower according to any one of claims 1 to 6, wherein a filter member for removing dust is provided at an opening of the suction port (12).   The heat resistance according to any one of claims 1 to 7, wherein an elastic flexible joint (F) for connecting to a pipe is connected to the suction port (12) and the discharge port (13). Electric blower.