JPH0685905U - Bent duct - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reduce the reinforcement of the current plate. [Structure] A straightening vane is installed inside the duct along the bending of the duct, and the straightening vane in the bent duct that performs a straightening action is configured to bulge inward on the upstream side and thicker on the downstream side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bent duct that is used for sending a fluid such as a liquid, a granular material, or a gas.

[0002]

[Prior art]

 FIG. 2 is an explanatory view of a conventional bent duct used for sending a fluid such as liquid, powder, and gas. In the figure, the main bending duct 01 has a flat plate having a straightening plate 02 having a curvature along the bending of the bending duct 01 inside to perform a straightening action, thereby reducing the pressure loss of the fluid flowing inside. There is.

[0003]

[Problems to be solved by the device]

In the conventional bent duct as described above, since the lengths L ₁ and L ₂ of the flow lines inside and outside the straightening vane 02 are in the relationship of L ₂ > L ₁ , the flow velocity v ₁ and v ₂ is v ₂ > v ₁ , and pressures P ₁ and P ₂ are P ₁ > P _{2 according} to Bernoulli's theorem, and a force is generated in the outer radial direction, that is, in the same direction as the centrifugal force. This force becomes stronger as the velocities v ₁ and v _{2 of the} fluid flowing inside are larger and the curvature of the bent duct 01 is smaller, so that the force acting toward the outer side of the radius becomes larger and reinforcement of the current plate 02 is required. It

[0004]

[Means for Solving the Problems]

 The bent duct according to the present invention is intended to solve the above problems. In a bent duct that has a straightening vane installed along the bending of the duct to perform a straightening action, the straightening vane swells inward on the upstream side and is thickly downstream. It is characterized by a configuration that becomes thinner on the side.

[0005]

[Action]

 That is, in the bent duct according to the present invention, the straightening vanes are installed inside the duct along the bending of the duct, and the straightening vanes in the bent duct that perform the straightening action have a shape that swells inward on the upstream side and thin on the downstream side. However, since the straightening vane is shaped so that the length of the streamline inside the straightening vane becomes longer, the pressure inside the straightening vane becomes smaller and the straightening vane goes to the center of the radius of curvature, that is, it is opposite to the centrifugal force. Directional force is generated.

[0006]

【Example】

FIG. 1 is an explanatory view of a bending duct according to an embodiment of the present invention. In the figure, the bent duct 1 according to the present embodiment is used for sending fluid such as liquid, powder or gas, and a rectifying plate 2 is installed inside to perform rectifying action. The pressure loss of flowing fluid is reduced. The straightening plate 2 of the main bending duct 1 is not flat, and has a curvature along the bending of the bending duct 1 on the outer side as shown in FIG. 3A, but on the inner side, the upstream side gently swells inward and is thicker. In addition, the downstream side is gradually thinned to form a curve in which the upstream side curve and the downstream side curve are continuously and gently connected. As shown in FIG. The streamline lengths L ₁ and L ₂ satisfy the condition of L ₁ > L ₂ .

In the conventional bent duct, the length L of the streamline inside and outside the straightening vane₁, L ₂ Is L₂> L₁Since there is a relationship of₂Is v₂> V₁ , And pressure P according to Bernoulli's theorem₁, P₂Is P₁> P₂Then, a force is generated in the outer direction of the radius, that is, in the same direction as the centrifugal force. This force is the velocity v, v of the fluid flowing inside.₂Is larger and the curvature of the bent duct is smaller, the force acting in the outer direction of the radius is larger and the rectifying plate needs to be reinforced. However, in this bending duct, the rectifying plate 2 is located inside the rectifying plate 2 and Outer streamline length L₁, L₂Is L₁> L₂And the pressure P inside and outside the straightening vane 2 is determined by the continuity condition and Bernoulli's theorem.₁, P₂Is P₁<P₂Then, a force toward the center of the radius and a force F toward the opposite direction of the centrifugal force are generated. As described above, the centrifugal force is generated by the flow of the fluid, and at the same time, the force F opposite to the centrifugal force is generated due to the pressure difference between the inner side and the outer side of the rectifying plate 2. The reinforcement of the plate 2 can be reduced. In addition, the centrifugal force due to the flow of the fluid is the velocity of the fluid v, v₂Becomes larger as becomes, but the force F toward the inner side of the radius generated in the straightening vane 2 is the velocity v 1, v 2.₂Since it increases in proportion to the square of, the fluid velocity v, v₂The larger is the greater the effect of canceling centrifugal force.

[0008]

[Effect of device]

 The bent duct according to the present invention is configured as described above, and since a force in the direction opposite to the centrifugal force is generated in the straightening vane, it is possible to reduce the reinforcement of the straightening vane by canceling the centrifugal force. .

[Brief description of drawings]

FIG. 1 (a) is a sectional view of a bent duct according to an embodiment of the present invention, and FIG. 1 (b) is an explanatory view of the action of a current plate.

FIG. 2 (a) is a cross-sectional view of a conventional bent duct, and FIG. 2 (b) is an operation explanatory view of the current plate.

[Explanation of symbols]

 1 bent duct 2 straightening plate

Claims (1)

[Scope of utility model registration request] 1. A bent duct in which a straightening vane is installed along the bending of a duct to perform a straightening action, wherein the straightening vane has a shape that swells inward on the upstream side and becomes thicker on the downstream side. Bending duct.