JPH01177500A - Jet fan - Google Patents

Abstract

PURPOSE:To reduce the number of jet fans, by a method wherein impellers are mounted on shafts at both ends of an electric motor, and flow straightening lattices are disposed on the reverse side to the electric motor of the impeller and right in the vicinity of the impeller. CONSTITUTION:Impellers 103 and 103', having mounting angles of blades 105-180 deg. different from each other, are mounted on shafts at both ends of an electric motor 102 situated in a cylindrical blast cylinder 101. Flow straightening lattices 7 and 7' formed by assembling sheets are disposed on the reverse sides, to the electric motor 102, of the impellers 103 and 103' and right in the vicinity of the impellers 103 and 103'. An air flow, having quantities of revolving components, generated by the impellers 103 and 103' is straightened by means of straightening lattices on the leeward side to produce an air flow having less amount of revolving components, and therefore the boosting force of a jet fan is increased. This constitution enables reduction of the number of jet fans.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is directed to an axial blower (commonly known as a jet fan, hereinafter referred to as a jet fan) that is installed on the ceiling of a road tunnel, etc., and ventilates the entire tunnel with its jet stream. It is related to.

BACKGROUND OF THE INVENTION Conventionally, this type of jet fan has an electric motor 102 installed inside a blower tube 101, as shown in FIGS. 3 and 4.
Impellers 103, 103'' are installed at both shaft ends of this electric motor 102.
The impeller 1Q3゜103' was directly connected to the impeller 1Q3゜103', and was equipped with muffler tubes 104 at both ends to reduce the noise generated from the impeller 1Q3゜103'. The impellers 103° and 103' have blades 1 of the same shape.
05 and a hub 106, and the blade 105 was set at an appropriate mounting angle α. The impellers 103 and 103' were mounted such that the mounting angles α of the blades 105 differed by 180°.

In the above configuration, for example, when the electric motor 102 rotates clockwise when viewed from the direction A in the figure, the impeller 103
, 103' rotate to generate wind in the B direction, and conversely, when the electric motor 102 rotates counterclockwise, it generates K in the C direction. That is, by changing the direction of rotation of the electric motor 102, the direction of the headwind is reversed, and the same amount of airflow is generated in each case.

Problems to be Solved by the Invention In such a conventional configuration, the impeller rotates in a plane perpendicular to the axis of the blower and performs work on the air.
The airflow generated by the impeller will have many swirling components. Due to the influence of this swirling flow, the boost pressure required when ventilating a long tunnel is low, resulting in the problem that the number of jet fans installed in the tunnel must be increased.

The present invention is intended to solve all of these problems, and aims to provide a jet fan that reduces swirling components of airflow as much as possible and has a high boost pressure.

Means for Solving the Problem In order to solve this problem, the present invention attaches impellers with blade installation angles different from each other by 1800 degrees to the shafts at both ends of the electric motor provided in the blower tube, and It had an anti-military motive, and had a jet fan configuration in which a rectifying grid made of thin plates, etc. was installed nearby.

Effect: With this configuration, the air flow with a large swirling component generated by the first impeller is always rectified by the rectifying grid on the leeward side of each impeller, regardless of whether the impeller is rotating in the forward or reverse direction. This creates an airflow with less swirling components.

EXAMPLE Hereinafter, an example of the present invention will be explained based on FIGS. 1 and 2. In the figure, the same reference numerals are used for the same components as in the conventional example, and the explanation thereof will be omitted. The feature of this embodiment is that the impeller 103 is located on the side opposite to the motor, and
03, a rectifying grid 7' made of thin plates or the like is arranged in a lattice pattern, and similarly, the rectifying grid 7 is arranged on the opposite side of the impeller 103' to the motor. That is, for example, when the electric motor 102 rotates clockwise when viewed from the direction A, the air flow with a large swirling component generated by the impellers 103, 103' flows in the direction B, and the air flow on the leeward side flows in the direction B. The current is rectified by the rectifying grid 7. Also, conversely, electric motor 1
02 rotates counterclockwise, the impeller 103'
, 103, which has a large swirling component, flows in the direction C and is rectified by the rectifying grid 7' on the leeward side.

In the above configuration, the airflow generated by the impellers 103, 103' is rectified by the rectifying grids 7, 7' disposed on the leeward side, and has a small swirling component, regardless of which direction it blows. Since the jet fan generates an air flow, the thrust that can be generated by a single jet fan is large, and when installed in a tunnel, a large boosting force can be obtained per jet fan.

Effects of the Invention As is clear from the above description of the embodiments, according to the present invention, by arranging the rectifying grid immediately on the anti-military motive side of the impeller, the swirling component generated by the impeller can be reduced. The large amount of airflow is rectified by the rectifying grid on the lee side, resulting in an airflow with less swirling components, so there is no need to increase the boosting force of the jet fan, and even in long tunnels, the number of jet fans installed can be reduced compared to the conventional method. It also has the effect of reducing damage.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of a jet fan according to an embodiment of the present invention, Fig. 2 is a side view of the same jet fan, Fig. M3 is a front sectional view of a conventional jet fan, and Fig. 4 is a side view of the same jet fan. It is. 101... Blower tube, 102... Electric motor, 103... Impeller, 103'... Impeller, 1o5... Blade, 7 ... Rectifier grating, 7'... Rectifier grating.

Claims (1)

[Claims] The shafts at both ends of the electric motor installed inside the cylindrical blower tube,
A jet fan comprising impellers whose blades are installed at angles of 180° different from each other, and a rectifying grid made of thin plates etc. arranged on the opposite side of the impeller and in close proximity to each impeller.