JPH03260400A - Air blower - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a blower device used in oil hot air heaters and the like.

BACKGROUND OF THE INVENTION A conventional blower device will be described below. As shown in FIG. 2, a driving motor 2 is located on the suction side of the impeller 1, and an orifice of a bell mouth 3 having a convex curved surface on the suction side is provided around the impeller. The legs of the U-shaped support fitting 4 that supported the motor 2 are fixed to the bell mouth 3 so that the impeller 1 is located at the center of the orifice.

A combustion tube 5 is provided on the discharge side of the impeller 1, and one end of a blower duct 7 provided to guide air from the impeller 1 to an outlet 6 is connected to a bell mouth 3.

The operation of the blower device configured as described above will be described below.

When the impeller 1 is rotated, air entering from the suction side of the impeller 1 flows around the motor 2, air from the side is sucked along the bell mouth 3, and the air enters the air duct 7.
The air blown out from the impeller 1 flows around the combustion tube 5 without flowing back to the suction side due to the bell mouth 3, receives heat from the combustion tube 5, becomes warm air, and is discharged from the outlet 6. be done.

Problems to be Solved by the Invention However, with the conventional tank bottom mentioned above, the impeller and bell mouth are located right next to the heat source in combustion equipment such as oil hot air heaters, so it is difficult to use metal materials that can withstand heat. Processed sheet metal is used, and processing issues limit the area and wall thickness of the impeller, as well as the curved shape of the bell mouth, and the bell mouth has convex curved surfaces on both the suction and outlet sides. It is difficult to do so.

In a bell mouth with a convex curved surface on the suction side, air flows smoothly on the suction side, but there is a problem in that swirling flow occurs near the concave curved surface on the outlet side, leading to energy loss. was.

The present invention solves the above-mentioned conventional problems, and aims to provide an air blower that can prevent swirling flow near the outlet, suppress separation of the air flow in the diffuser, and cool the diffuser.

Means for Solving the Problem In order to solve this problem, the blower device of the present invention includes a bell mouth having a convex curved surface on the suction side and a plurality of small holes, and a diffuser having a convex curved surface on the discharge side. This structure has an orifice with a gap between the bell mouth and the diffuser.This structure allows the air to flow smoothly on the suction side and the outlet side of the orifice, creating a gap between the bell mouth and the diffuser. The attraction effect of the gap provided in the bell mouth suppresses separation of the air flow from the diffuser, and furthermore, cold air from the outside is taken in through the small hole in the bell mouth.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. Components that are the same as those of the conventional air blower are designated by the same numbers as in FIG. 2, and their explanations will be omitted.

As shown in FIG. 1, the orifice is formed by a bell mouth 8 having a convex curved surface on the suction side and a plurality of small holes IO, and a diffuser 9 having a convex curved surface on the discharge side. Since the diameter of the bell mouth 8 is set smaller than the diameter of the diffuser 9, a gap 11 is formed between the bell mouth 8 and the diffuser 9.

The operation of the blower device configured as described above will be explained below.

When the impeller 1 is rotated, air flows from the suction side of the impeller l widely from all around the motor 2 as shown by arrow a, and air from the sides is sucked in along the bell mouth 8. , flows into the ventilation duct 7.

The air blown out from the impeller 1 as shown by the arrow is
The air flows around the combustion tube 5, receives heat from the combustion tube 5, becomes warm air, and is discharged from the outlet 6.

Moreover, the air flowing in along the bell mouth 8 as shown by the arrow C flows smoothly along the diffuser 9 in the case of a blown stool.

At this time, the flow of air near the gap 11 is at high speed and causes a pressure drop, resulting in an induced flow of air as shown by arrow d. Furthermore, the induced flow of air is drawn in from the outside through a small hole 10 provided in the bell mouth 8.

As described above, according to this embodiment, the orifice is formed by the bell mouth and the diffuser, and the bell mouth and the small hole are formed by providing a gap between the bell mouth and the diffuser.
The air flow through the orifice is smooth and there is no swirling flow, so there is no energy loss, and if the induced flow that occurs in the gap is likely to cause separation in the air flow along the diffuser, it will cause a boundary layer. It plays the role of supplying energy to the air and suppresses peeling, thereby increasing the efficiency of the blower. Additionally, the low salinity air sucked in through the Hellmouth pores cools the diffuser, improving the durability of the orifice.

Effects of the Invention As is clear from the description of the embodiments above, the present invention comprises a bell mouth having a convex curved surface on the suction side and a plurality of small holes, and a diffuser having a convex curved surface on the discharge side. By providing an orifice with a gap between the bell mouth and the diffuser, swirling flow does not occur on the outlet side of the orifice, and separation of the air flow from the diffuser can be suppressed.
It is possible to realize a high-performance, long-life blower device that can cool the diffuser.

[Brief explanation of drawings]

1...impeller, 2... Motor, 5... combustion cylinder, 8...bellmouth, 9...Diffuser, 10... small hole, 11...Gap area.

Claims (1)

[Claims] It is equipped with an impeller with a drive motor attached to the suction side, a cylindrical combustion tube located on the discharge side of the impeller, and a convex curved surface on the suction side surrounding the impeller. A blower device comprising a bell mouth with small holes and a diffuser having a convex curved surface on the discharge side, and includes an orifice with a gap between the bell mouth and the diffuser.