JPS59200099A - Blower - Google Patents

Abstract

PURPOSE:To provide a sufficient static pressure durable against an ignition pressure when air-fuel mixture is ignited in a combustion chamber, and permit a necessary amount of air for steady combustion to be supplied, by constituting a bellmouth of a flange, cylindrical portion, guide plate, partitioning plate and closure plate. CONSTITUTION:A guide plate 5c is a semi-circular disc having a diameter equal to an outer diameter of a cylindrical portion 5b, and is designed to close a suction opening 1d of an impeller 1 except a semi-circular opening thereof. A partitioning plate 5d is projected from an edge portion on the opening side of the guide plate 5c in such a manner as to be inserted into the suction opening 1d by 20-30% of a width of the impeller, and is designed to partition a closure portion as closed by the guide plate 5c from the semi-circular opening in the suction opening 1d. Further, there is provided a blocking plate 5e on an outer peripheral surface of the cylindrical portion 5b for blocking a spacing between the cylindrical portion 5b and a wind cutting portion 4c of a casing 4. With this arrangement, a part of the fluid discharged from the impeller 1 is returned from a chamber of the impeller 1 to the suction opening 1d as a return fluid without loss of energy, and is boosted again, thereby obtaining a sufficient static pressure durable against an ignition pressure and permitting a necessary amount of air for steady combustion to be supplied.

Description

[Detailed description of the invention] The present invention relates to a blower.

The air discharged from the blower is mixed with fuel and sent into the combustion chamber of a gas furnace, heavy oil furnace, etc., and ignited within the combustion chamber. The ignition pressure is about 3 to 5 times that of the Therefore, in order to ignite the air-fuel mixture and achieve steady combustion, the static pressure of the gas being fed must be higher than this ignition pressure. If this static pressure is not higher than this ignition pressure, it will be difficult to forcibly send gas into the combustion chamber at the time of ignition, making ignition difficult.

In conventionally known blowers, the static pressure of the gas being fed was not sufficient to withstand the ignition pressure, and ignition was not easily achieved. In order to increase this static pressure, it was necessary to increase the diameter of the impeller or use a multi-stage type, but then the motor that drives the impeller would also have to be large, making the entire blower larger. , it becomes expensive and difficult to handle. In addition, as the total pressure increases, the air volume and required power increase, so the air volume is too large for actual use.
There was a problem that operating costs increased.

The present invention has been made from the following viewpoints:
The object of the present invention is to obtain sufficient static pressure to withstand the ignition pressure when the air-fuel mixture is ignited in the combustion chamber, and to send out the amount of air necessary for steady combustion. To provide a small, easy-to-handle blower at low cost.

The gist of this is that the side plate on the side opposite to the inlet of the casing forming the impeller chamber is brought close to the shroud of the impeller, and a semicircular guide plate is provided on the edge of the cylindrical portion of the bell mouth. The central hole of the cylindrical part is closed leaving a half-moon-shaped opening on the side substantially opposite to the wind blowing part, and a partition plate is provided on the edge of the guide plate on the opening side to protrude inside the suction port of the impeller, and further, A sealing plate is installed on the outer circumferential surface of the cylindrical part of the bell mouth to close the gap between the cylindrical part of the bell mouth and the wind section of the casing, and the energy of the return airflow generated from the high pressure part of the impeller chamber toward the inside of the impeller is dissipated. The goal is to allow the impeller to suck the air again and further increase the pressure without losing it.

The present invention will be described in detail below based on the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of a blower according to the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1,
Fig. 3 is a front view showing the shape of the bell mouth, Fig. 4 is a side view thereof, Fig. 5 is a graph showing the characteristics of a known blower, and Fig. 6 is a graph showing the characteristics of the blower according to the present invention. .

In each figure, the same reference numerals indicate the same components.

In Figures 1 to 4, 1 is an impeller, la is a blade, 1b is a shroud, Ic is a shroud, 1d is an impeller suction port, 2 is a hub, 3 is a driving motor for impeller 1,
□・4 is a casing, 4a, 4b are side plates of the casing 4, 4c is a wind section, 4d is a hole provided in the side plate 4b, 4 is a discharge port, 5 is a bell mouth, 5a is an annular flange, 5b is a cylindrical portion , 5c is a guide plate, 5d is a partition plate, 5e
is a blocking plate.

The impeller 1 is a member in which a plurality of blades 1a, 1a are disposed in a dispersion-like manner between a pair of shrouds lb, Ic, and the center hole 1d of the shroud 1c forms the suction port of the impeller.

Further, a hub 2 is attached to the center of the impeller 1, and the hub 2 is fixed to the shaft of a motor 3 attached to a side plate 4a of the casing 4.

The shape of the impeller 10 blades 1a, 1a is as shown in this embodiment. In addition to , radial, turbo, airfoil, etc. may be used.

An impeller chamber for housing the impeller 1 is configured inside the casing 4, and a spiral cavity that increases in proportion to the winding start angle is formed on the discharge side of the impeller 1 in the impeller chamber. .

The side plate 4a of the casing 4 is the shroud 1b of the impeller 1.
The wind blowing section 4c is arranged to face the impeller 1 with a small distance between the impeller 1, the side plate 4a, and the wind blowing section 4C.
Configure so that there are no gaps between the

Further, a hole 4d, which is appropriately larger than the suction port 1d, is provided in the side plate 4b of the casing 4, facing the suction port 1d of the impeller 1.

- Generally, the gas discharged from the impeller of a blower increases its pressure as it rotates in the direction of rotation of the impeller through a spiral cavity in the impeller chamber, and the total pressure reaches its maximum at the end of the cavity. becomes. At this time, when the discharge port is throttled to reduce the amount of air being discharged, a return airflow shown at 8 in the figure is generated from the end of the spiral cavity through between the blades of the impeller and toward the inside of the impeller.

In known blowers, this return airflow violently collides with external gas at the suction port, loses its energy, is sucked into the impeller again, is discharged into the spiral cavity, and is circulated within the impeller chamber. , the exhaled energy is almost lost.

In addition, in the known blower, since there is a gap between the impeller 1 and the side plates 4a and 4b of the casing 4, there is a gap between the high pressure part at the end of the spiral cavity and the low pressure part at the start end. A gap is created in the impeller chamber, and when the discharge port is throttled, the gas in the high-pressure section is blown back to the low-pressure section through this gap, circulates within the impeller chamber, and discharge energy is lost.

Therefore, the gist of the present invention is to cause the return airflow to be sucked in again by the impeller and to further increase the pressure without losing the energy of the return airflow.

As shown in FIGS. 3 and 4, the bell mouth 5 includes an annular flange 5a, a cylindrical portion 5b, a guide plate 5C1 partition @5d, and a closing plate 5e.

The outer diameter of the cylindrical portion 5b is set to be slightly smaller than the inner diameter of the impeller 1, and its width is such that when the bell mouth 5 is attached to the casing 4, the tip portion is approximately on the same plane as the shroud IC of the impeller 1. It is configured such that it faces the suction port 1d with a small distance.

The guide plate 5c is a semi-disk having the same diameter as the outer diameter of the cylindrical part 5b, and is fixed to the edge of the tip of the cylindrical part 5b, so that the center hole of the cylindrical part 5b is closed leaving a half-moon-shaped opening 5a. Ru.

When the bell mouth 5 is attached to the casing 4ε,
The guide plate 5C is substantially on the same plane as the shroud IC of the impeller 1, and is placed 157I apart from the suction port ldi of the impeller 1, leaving a half-moon-shaped opening. Further, this half-moon-shaped opening serves as an inlet for introducing external gas.

The partition plate 5d has a number on the edge on the opening side of the guide plate 5C, and projects from this edge into the suction port Id of the impeller 1, and the length of the protrusion is approximately <When installed in the hole 4d provided in the plate 4b, the impeller 1
Set it so that 20 to 50% of the impeller width goes inside.

The partition plate 5d is configured to partition a portion of the suction port of the impeller 1 that is closed by the guide plate 5C from a half-moon-shaped opening, and the return airflow shown by 8 in FIG. 1 is directed from the half-moon-shaped opening. This prevents energy loss due to violent collision between the inhaled external gas and the edge of the opening.

In this embodiment, the partition plate 5d is installed by bending the edge of the guide plate 5C on the opening side using a press or the like.
□), but the partition plate 5d is replaced by the guide plate 5C.
It is also possible to create a similar configuration by separately forming the opening and fixing it to the edge of the half-moon-shaped opening.

The closing plate 5c is fixed to the outer periphery of the cylindrical portion 5b, and the bell mouth 5
When attached to the casing 4, the tip thereof contacts the wind section 4c of the casing 4 and closes the gap between the terminal end and the starting end of the spiral void.

As a result, the side plate 4a of the casing 4 is brought close to the shroud 1a of the impeller 1, and the wind section 4a is opposed to the impeller 1 with a very small gap, and the high-pressure part at the end of the spiral cavity and the starting end The structure is such that no gap is formed between the low-pressure part and the low-pressure part of the part.

As shown in FIGS. 1 and 2, the bell mouth 5 has a partition plate 5.
d has an inclination of 15 to 30 degrees with respect to the center line A-A in the figure, that is, the impeller center line that is perpendicular to the discharge pipe center line of the casing 4, and the half-moon-shaped opening is the wind section 4c. is on the substantially opposite side, and is attached to the hole 4d provided in the side plate 4b of the casing 4 facing the suction port of the impeller 1 so that the tip of the sealing plate is locked to the wind section 4C of the casing.

This mounting angle is set so that the partition plate 5d follows the direction of the return airflow indicated by the number, so that the energy of the return airflow is not lost.

When the impeller 1 is driven and rotated by the motor 3, external gas is sucked in through the half-moon-shaped opening not covered by the guide plate 5c of the bell mouth 5, and due to the centrifugal force accompanying the rotation of the impeller 1. It is discharged outward from between the blades 1a and Ia.

The gas discharged into the spiral cavity of the casing 4 has static pressure increased within the cavity and is discharged from the discharge port 4. At this time, the gas reaches its maximum level at the end of the cavity. A part of the pressurized gas is ejected as a return airflow from the high-pressure part of the impeller chamber through between the blades 1a and 1a of the impeller 1 in the direction 8 in the figure, and the guide plate 5c and the partition plate 5d of the bell mouth 5.
The gas is guided back to the low-pressure part on the suction side of the impeller 1 without violently colliding with the external gas sucked in through the semicircular opening.

The gas returned to the suction side of impeller 1 is returned to impeller 1.
The air is sucked in by the air, and the pressure is further increased in the same manner as described above. A part of it is discharged from the discharge port 4e, but the other part becomes a return airflow and is returned to the suction side of the impeller 1, where the pressure is increased. .

The above cycle is repeated, and part of the gas that is sucked in through the opening of the bell mouth 5 and pressurized by the impeller 1 is recirculated as a return airflow, and the pressure is repeatedly increased without losing its energy. The gas discharged from the outlet 4e has a higher total pressure than that of known blowers.

Here, the characteristics of the blower according to the present invention will be explained in comparison with the characteristics of a known blower using graphs shown in FIGS. 5 and 6.

FIG. 5 is a graph showing the characteristics of a known blower, and FIG. 6 is a graph showing the characteristics of the blower according to the present invention.

In Figures 5 and 6, ■ and ■' are curves showing the relationship between air volume and static pressure, ■ and ■' are curves showing the relationship between landscape and current, and the vertical axis shows static pressure or current; The horizontal axis shows the air volume.

In a conventionally known blower, as shown in FIG. 5, when the air volume is increased, the static pressure decreases, and the current increases at a substantially constant rate. This shows that the energy of the current is not converted into static pressure but into air volume.

On the other hand, in the blower according to the present invention, as shown in FIG. 6, when the air volume increases, the static pressure decreases and the current decreases at first, but at a constant level as shown by the chain line in the figure. It becomes minimum at the air volume value and then increases.

In this case, when the air volume is decreased, the current initially decreases at a nearly constant rate, similar to the characteristics of known blowers, but reaches a minimum at a certain air volume value, indicated by the chain line in the figure. ,
After that, it increases. At this time, the static pressure increases at a constant rate of increase as indicated by the chain line in the figure. This shows that the energy of the current is converted into static pressure within the range of air volume less than a certain air volume value indicated by the chain line in the figure.

As mentioned above, the special feature of the blower according to the present invention is that the maximum value of static pressure is larger than that of known blowers, and the static pressure is high even at the same airflow value, especially when the airflow is constant. A large static pressure can be obtained within a range of air volume smaller than the above value.

This shows that when the air blower according to the present invention is used, sufficient static pressure can be obtained to withstand the ignition pressure when the incoming air and fuel gas are mixed and ignited.

Moreover, for this reason, when using the blower directly, it can be operated with more leeway than known blowers.

Since the present invention is configured in a diagonal manner, in accordance with the present invention, a part of the gas discharged from the impeller becomes a return airflow and returns from the impeller chamber to the suction port of the impeller without losing its energy. The total pressure of the gas discharged from the discharge port increases, increasing the pressure of the gas in gas furnaces, heavy oil furnaces, etc.
When the air-fuel mixture sent into the fA1 chamber is ignited, sufficient static pressure is obtained to withstand the ignition pressure, the amount of air necessary for steady combustion is sent out, and the structure is simple. , it is possible to provide a small, easy-to-handle blower at low cost.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a blower according to the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1,
Fig. 3 is a front view showing the shape of the bell mouth, Fig. 4 is a side view thereof, Fig. 5 is a graph showing the characteristics of a known blower, and Fig. 6 is a graph showing the characteristics of the blower according to the present invention. . 1−−〜−−−−−−−・−1−−−・−・−Impeller 1 b, 1 c−−−−・−−−−・・−・−・−・
・Shroud 1d--------1--
−−−Impeller suction port 3−・−−−−・−・・・−−
m--・--1--Drive motor 4・----
---・---1-----Casing 4a, 4
b---------------One side plate 4 c-
−−−・−11～−−−−−−−−−−−−−−One wind section 4e・−・・−・−・−・・−・−=−−1−−Discharge port 5・−−−−−−・−−−−・−・−・・−Bell mouth 5a−−・−・・−1−−−−−・・−・−・・−・
Flange 5b--・-----1--------Guide plate 5c-------------
-----m--・-Partition plate 5d-----
1.-----Sealing plate patent applicant Olympia Kogyo Co., Ltd. Agent (7524) Mogami Shotabe-J Fig. 2 5 Fig. 3 Fig. 4 Flow pressure 1 iW Electrostatic flow pressure No. 6 figure

Claims (3)

[Claims] (1) In a blower that sucks gas into the impeller chamber from the inlet of the bell mouth, rotates the impeller installed in the impeller chamber to increase the pressure, and discharges it from the discharge port, The side plate on the opposite side from the suction port is placed close to the shroud of the impeller, and a semi-disk-shaped guide plate is provided on the edge of the cylinder part of the bell mouth, so that the center hole of the cylinder part is formed in a semi-moon shape on the side substantially opposite to the wind blowing part. A partition plate is provided on the edge of the guide plate on the side of the opening to protrude into the suction port of the impeller;
The blower as described above is further characterized in that a sealing plate is provided on the outer peripheral surface of the cylindrical portion of the bell mouth to close a gap between the cylindrical portion of the bell mouth and the wind section of the casing. (2) The blower according to claim 1, wherein the length of the partition plate protruding into the suction port of the impeller is 20% or more and 50% or less of the width of the impeller. (3) A patent in which the arc of the half-moon-shaped opening matches the arc of the impeller suction port, and the partition plate has an angle of 15 to 30 degrees with the impeller center line, which is perpendicular to the casing's discharge pipe center line. A blower according to claim 1 or 2.