JPH06147648A - Hot air type heater - Google Patents

Abstract

PURPOSE:To reduce the lowering of flow rate of supply air in a short period of time while contriving the compacting of the main body of an instrument. CONSTITUTION:The heater is provided with a box type duct 7, covering a burner 3 and a combustion tube 5, and a fan 9 for convection, which supplies air for warm air heating into the duct 7, while the fan 11 of the fan 9 for convection is incorporated into the duct 7 and a bell mouth plate 8 is provided at the rear part of the duct opposed to the fan 11. The mounting part of the bell mouth plate 8 to the peripheral wall of the duct is formed so as to be a tapered part 8a and a venting hole 13 is provided on the peripheral wall of the duct opposed to the tapered part 8a of the bell mouth plate 8 or both of the fan side of the bell mouth plate 8 and the opposite side of the fan 11 are formed so as to be rounded. Accordingly, the reduction of amount of intake air can be restrained even when dust is adhered to the guard 10 of the fan 9 for convection whereby the safety property of the heater can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoor open type hot air heater.

[0002]

2. Description of the Related Art An indoor open type hot air heater provided with a conventional bell mouth plate is shown in FIG. 7 and FIG.
And a combustion tube 32 for guiding the combustion gas from the burner section 31,
The air from the convection blower 34, which is formed of the duct 33 and faces the combustion tube 32, is mixed with the combustion gas discharged from the combustion tube 32, and hot air is blown from the air outlet 35 to blow the air inside the room. It is designed to be heated. Here, a bell mouth plate 36 is attached to the rear portion of the duct 33, and a ventilation hole 37 is provided in the duct peripheral wall located at the rear of the bell mouth plate 36. With this configuration, a convection air intake hole of the fan guard 38 is provided. Even if the opening area of 39 is small, the air inside the device body can be taken in through the ventilation hole 37 of the duct 33. Even if dust adheres to the surface of the fan guard 38, the downflow rate of the air volume is small and the temperature inside the device body is low. It is configured to prevent rising and the like.

[0003]

However, in the above-mentioned conventional structure, the vent hole 37 provided at the rear of the bell mouth plate 36 is provided.
Since the size of the device is restricted by the distance between the bell mouth plate 36 and the device exterior 40, it has become impossible to sufficiently take in the air inside the device body. That is, at present, the warm air heaters are becoming more compact, and designability tends to be emphasized. Therefore, the intervals of the ducts 33 in which the ventilation holes 37 are provided are narrowed, and the air circulation in the device body is poor. Was tending to become.

As shown in FIG. 9, the bell mouth plate 36 has a rounded shape 36a from the rear side of the main body of the apparatus. A large dead space 41 is formed between the opening edge of the rounded 36a part and the duct peripheral wall. Therefore, turbulent flow was generated in this part, and the flow velocity was reduced, resulting in a decrease in the air flow rate.

Therefore, in such a device structure, when indoor dust begins to adhere to the fan guard 38 after the first use, the rate of reduction in the amount of air blown by the convection blower 34 is large even though the amount of dust adhered is not so large. , The exterior temperature of the device body rises within a short time, or causes incomplete combustion in a type that uses a part of the air from the convection blower 34 as a part of the combustion air, There was a problem of lack of reliability in terms of safety. And for those equipped with an overheat prevention device, this will operate in a short time and the operation of the equipment will automatically stop,
Unless the dust adhering to the fan guard 38 is frequently removed, the operation of the equipment cannot be continued,
There was a problem that it was not easy to use.

The present invention is intended to solve the above problems, and it is an object of the present invention to reduce the blow rate in a short time while reducing the size of the device body and improving the design.

[0007]

In order to solve the above problems, the present invention is directed to a burner for performing combustion, a combustion cylinder provided so as to cover the burner, and a box shape provided so as to cover the burner and the combustion cylinder. A duct and a convection blower attached to the back of the main body for supplying warm air into the duct, and a fan of the convection blower is installed inside the duct and a duct facing the fan. A bell mouth plate is provided in the rear part, and a mounting portion of the bell mouth plate to the duct peripheral wall portion is formed in a tapered shape, and a ventilation hole is provided up to the duct peripheral wall portion facing the tapered portion of the bell mouth plate, Alternatively, the bell mouth plate is formed in a round shape on both the fan side and the side opposite to the fan.

[0008]

According to the present invention, even if the main body of the apparatus is made compact, the ventilation hole provided in the peripheral wall of the duct can be made large enough to be formed so as to face the tapered portion of the bell mouth plate. The air inside the fuselage can be taken in sufficiently. Further, the flow of air before and after the bell mouth, that is, at the inlet and the outlet becomes smooth, and the amount of air supplied through the bell mouth plate increases accordingly. Therefore, with a focus on designability, even if the fan guard has a smaller convection air intake hole opening area and dust is more likely to adhere to the fan guard in a short time, the reduction rate of air flow will be lower than before. It can be kept small, and it is possible to prevent an increase in temperature inside the machine body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, 1 is a main body having a hot air outlet 2 on the front surface, and 3 is a leg 5 on a stand 4 of the main body 1.
In this embodiment, a burner that vaporizes and burns liquid fuel is used. 6 is the above burner 3
Is a horseshoe-shaped duct provided in the main body so as to surround the above-mentioned combustion cylinder 6, and a bell mouth plate 8 is attached to the inside of the rear. The bell mouth plate 8 has a tapered portion 8a attached to the peripheral wall of the duct to secure a wide space for forming a vent hole described later. Reference numeral 9 denotes a convection blower for supplying warm air into the duct 7, which is attached to the rear surface of the main body through a fan guard 10.

The propeller fan 11 of the convection blower 9 is located inside the duct 7 and is opposed to the bell mouth plate 8. Although a large number of air intake holes 12 are formed on the rear surface and the entire peripheral surface of the fan guard 10, the projecting dimensions of the fan guard 10 have become smaller due to the recent downsizing of the device body. The total area of 12 tends to decrease. Reference numeral 13 is a ventilation hole for compensating for the reduced amount of the air intake hole 12. A large number of ventilation holes are formed in the duct peripheral wall portion behind the bell mouth plate 8, and the convection blower 9 is also provided with air from the ventilation hole 13. To suck up. The ventilation hole 13 is formed in a wide space in which a mounting portion of the bell mouth plate 8 to the duct peripheral wall portion is secured as a tapered shape 8a, and its size is opposed to the tapered portion as compared with the conventional one. It is big.

In the above structure, first, the general operation of the hot air heater will be described. The combustion flame formed in the burner 3 is blown by the convection blower 9 by the fan guard 1
The air obtained through the convection air intake hole 12 provided at 0 and the air inside the machine obtained through the ventilation hole 13 provided at the duct peripheral wall behind the bell mouth plate are supplied to complete the combustion flame.
The combustion heat generated by the combustion flame heats the combustion cylinder 6, and the air sent from the convection blower 9 exchanges heat with the combustion cylinder 6 to be discharged into the room as warm air from the air outlet 2 to heat the room. .

Here, the opening area of the convection air intake hole 12 of the fan guard 10 is small, and dust adheres to the fan guard 10 in a short time after the operation of the equipment, and the convection air intake hole 12 is formed.
Even if many of them are blocked, the ventilation hole 13 of the duct 7 is larger than the conventional one, so that sufficient air can be taken in from the inside of the body, and the down rate of the warm air volume due to dust adhesion can be reduced, and It is possible to prevent a significant reduction in air volume.

3 and 4 show another example of the invention. In this example of the invention, the bell mouth plate 8 is not provided with the tapered shape 8a and the ventilation hole 13 is provided.
Has the same size as the conventional one, but the bell mouth plate 8 has a rounded shape 8 on both the fan side and the side opposite to the fan.
The throat portion 8d between the two rounded portions is formed in a straight pipe shape while being formed in b and 8c.

According to this construction, the wind from the convection blower 9 is efficiently taken into the bell mouth plate 8 while being rectified by the rounded shape 8b on the fan side as in the conventional case, and the taken-in wind is taken from the front side. The air flows smoothly forward along the rounded shape 8c, and there are few sudden changes in the cross section of the flow path, so there is no turbulent flow, and the blast loss is extremely small. Therefore, the reduction rate of the warm air volume due to the dust adhered to the fan guard 10 can be reduced, and the rapid air volume reduction can be prevented.

Further, the bell mouth plate 8 has both rounded shapes 8b and 8b.
Since the throat portion 8d between the c is formed in a straight pipe shape, it is possible to always secure a stable air flow rate even if the positional relationship between the propeller fan 11 and the bell mouth plate 8 slightly changes due to the component size, assembly variation, or the like. Therefore, even if dust adheres to the fan guard 10, the down rate of the warm air volume can be reduced.

Therefore, in the case where a part of the air from the convection blower 9 is used as the combustion air as in both of the above-mentioned invention examples, it is introduced into the combustion cylinder 6 by the reduction of the air volume due to the dust adhesion of the fan guard 10. The amount of combustion air to be generated does not decrease in a short time, and deterioration of exhaust gas performance such as CO generation due to insufficient air can be prevented as much as possible.

Further, when the air flow is reduced, the exterior temperature of the equipment body does not rise abnormally in a short time, and an overheat prevention device 14 is provided above the duct 7 to cause an abnormal temperature rise. However, even in the case where the combustion is stopped and the cleaning is urged, the combustion stop due to the temperature rise is reduced, and the trouble of frequently removing the dust adhering to the fan guard 10 is eliminated, and at the same time, the apparatus can be used for a long time. Driving can be continued.

Further, a taper shape 8a in front of the bell mouth plate 8 is formed.
Has the effect of blocking the radiant heat from the high-temperature burner and preventing the temperature rise of the exterior of the fuselage.

FIGS. 5 and 6 show still another invention example, which is a combination of the above first and second invention examples. That is, the bell mouth plate 8 is formed with a tapered shape 8a to form the ventilation hole 13 of the duct 7 large, and both the fan side of the bell mouth plate 8 and the side opposite to the fan are formed into rounded shapes 8b and 8c. The groove portion 8d between the two rounded portions has a straight pipe shape.

Therefore, according to this structure, the effects obtained by the first and second invention examples can be synergistically obtained, and the down rate of the hot air sealing amount can be greatly reduced.

[0021]

As is apparent from the above description of the embodiments, the present invention is compact and compact because it is possible to make the equipment compact and to supplement the air volume reduction due to the reduction of the convection air intake hole area of the fan guard. It is possible to provide various types of equipment and prevent abnormal overheating of the equipment in a short time. In addition, in the case of using a part of the air taken in from the convection air intake hole as a part of the combustion air, it is possible to prevent incomplete combustion due to insufficient air and to provide an overheat prevention device. In that case, it is easy to use, such as preventing it from operating in a short time,
In addition, it is possible to obtain a compact hot air heater with excellent dust resistance and high safety.

[Brief description of drawings]

FIG. 1 is a plan view of a warm air heater according to an embodiment of the present invention.

[Figure 2] Cross-sectional view of the hot air heater

FIG. 3 is a sectional view showing another invention example.

FIG. 4 is an enlarged sectional view of the bell mouth plate.

FIG. 5 is a plan view showing still another invention example.

FIG. 6 is a sectional view of the same.

FIG. 7 is a plan view of a conventional warm air heater.

FIG. 8 is a sectional view of the same.

FIG. 9 is an enlarged sectional view of the bell mouth plate.

[Explanation of symbols]

 3 Burner 6 Combustion tube 7 Duct 8 Bell mouth plate 8a Tapered portion 8b R-shaped portion 8c R-shaped portion 8d Throat portion 9 Convection blower 11 Fan 13 Vent hole

Claims (4)

[Claims] 1. A burner for performing combustion, a combustion cylinder provided so as to cover the burner, a box-shaped duct provided so as to cover the burner and the combustion cylinder, and hot air is supplied into the duct. In order to install a convection blower attached to the back of the main body for this purpose, the fan of the convection blower is installed inside the duct, and a bell mouth plate is provided at the rear of the duct facing the fan, and the bell peripheral wall of the bell mouth plate is provided. A warm air heater in which a portion to be attached to the section is formed in a tapered shape and a ventilation hole is provided in a duct peripheral wall facing the tapered portion of the bell mouth plate. 2. A burner for performing combustion, a combustion cylinder provided so as to cover the burner, a box-shaped duct provided so as to cover the burner and the combustion cylinder, and hot air is supplied into the duct. In order to install a convection blower attached to the back of the main body for this purpose, the fan of the convection blower is installed inside the duct, and a bell mouth plate is provided at the rear of the duct facing the fan, and the bell mouth plate is on the fan side. In addition, the hot air heater has a rounded shape on the opposite side of the fan. 3. A burner for performing combustion, a combustion cylinder provided so as to cover the burner, a box-shaped duct provided so as to cover the burner and the combustion cylinder, and hot air is supplied into the duct. In order to install a convection blower attached to the back of the main body for this purpose, the fan of the convection blower is installed inside the duct, and a bell mouth plate is provided at the rear of the duct facing the fan, and the bell peripheral wall of the bell mouth plate is provided. The portion to be attached to the portion is formed in a tapered shape, and a ventilation hole is provided in the duct peripheral wall facing the tapered portion of the bell mouth plate, and the bell mouth plate is rounded on both the fan side and the side opposite to the fan. A hot-air heater with a straight pipe shape at the groove between both rounded portions. 4. The hot air heater according to claim 3, wherein the throat portion between the two rounded portions of the bell mouth plate has a straight pipe shape.