JPS6023785A - Unbalanced flow prevention device - Google Patents

Abstract

PURPOSE:To prevent the biased flow of gas discharged from the outlet port of a flue by a method wherein a perforated plate is provided at the outlet port of the flue on the extension of a part of the curvature of the flue, having a radius of curvature larger than a predetermined value. CONSTITUTION:A stay 5 is provided in the outlet port of the flue on the extension of the curvature, whereat vanes 1 are not provided and the radius of curvature is large, and various kind of perforated plates are fixed to the stay 5 through bolts 7. In this case, the distribution of the flow of gas at the outlet of the curved part is measured by an actual operation of machine after attaching the vanes and the perforated plates are mounted at the outer side of the flue, which is having many elements of bias flow, properly. According to this method, the biased flow at the part of the outside of the curvature of the flue, in which the flow of gas is quickened, may be prevented. The perforated plates can be attached to the stay simply by the bolts, therefore, the operability may be improved and the rate of biased flow may be reduced owing to the flow regulating effect of the perforated plates.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a device for preventing uneven flow of gas flow in a flue.
The present invention relates to a drift prevention device suitable for preventing complicated drift in the curved portion of a flue connected to a heat pipe.

[Prior art]

BACKGROUND ART Conventionally, prevention of uneven flow of a gas flow at a flue curved portion of a duct for supplying a gas flow to a heat pipe (separated heat pipe f) has a configuration as shown in FIG.

That is, if the flue 3 bends sharply in the vicinity of the inlet when sending the gas flow 2 into the heat pipe 4, a biased flow will occur, so vanes 1 are provided in the curved part of the flue to prevent this. Normally, the gas flow 2 has a large curvature outside the radial center of the flue as shown in FIG. 2 at the curved portion of the flue, so the gas flow becomes faster and more gas flows easily.

In FIG. 2, Y indicates the center of curvature and Y' indicates the outside of the radius of curvature. The heat pipe 4 is a separate heat pipe,
When a bias occurs in the incoming gas flow, the efficiency of heat recovery is significantly reduced. Therefore, methods for preventing drifting have been devised in the past, and the example shown in FIG. 1 is based on a vane system. The vane l provided at the flue bend shown in FIG. 1 is usually formed during manufacturing and is placed in advance on the flue 3 by welding or gluing. Therefore, if drifting cannot be resolved in an actual machine, molded vanes must be installed by trial and error9, which has the drawback of lacking certainty in preventing drifting.

In addition, in order to approximate the actual model, scaled model tests have traditionally been conducted in advance, which cannot be said to be perfect in preventing drifting, and there are design problems in ensuring accurate uniform gas flow.

Furthermore, in order to eliminate imperfections in preventing drifting in an actual machine, it would require a great deal of labor and cost to modify the vane installation after the machine has started operation, which is not suitable for the actual situation.

[Purpose of the invention]

An object of the present invention is to provide a drift prevention device that can prevent drift of gas flow exiting from a flue outlet.

[Summary of the invention]

The present invention provides a plurality of vanes at appropriate intervals in a portion of the flue curved portion where the radius of curvature is smaller than a predetermined value, and
By providing at the flue outlet a perforated plate having the same area as the portion of the curved flue portion where the radius of curvature is larger than the predetermined value, it is intended to prevent the gas flow exiting from the flue outlet from being biased.

[Embodiments of the invention]

Examples of the present invention will be described below.

FIG. 3 shows an embodiment of the invention.

In the drawings, the same reference numerals as in the conventional example shown in FIG. 1 indicate the same parts and the same functions. This embodiment is different from the conventional example shown in FIG. The point is that several types of perforated plates 6 are fixed with bolts 7.

That is, in actual operation, the gas flow distribution is measured at the outlet of the bend after the vane is installed, and a perforated plate is installed as appropriate on the outside where there are many drifting elements.

This makes it possible to prevent drifting due to faster gas flow inside and outside the flue bend.

Therefore, according to this embodiment, the perforated plate can be easily attached with bolts, improving work efficiency, and the rectifying effect of the perforated plate can reduce the drift rate.

Further, according to this embodiment, the draft loss of the gas flow can be reduced by the combination with the vane.

Furthermore, according to this embodiment, as shown in FIG. 4, when the curved part does not have a vane and a perforated plate is provided over the entire surface of the flue outlet, in the case of a gas flow with a lot of dust, However, since the vane is provided inside the curved part, dust does not accumulate on the bottom surface of the parallel part.

Further, according to this embodiment, compared to a case where only vanes are provided, drift prevention can be easily operated using an actual machine without using a model test.

Further, according to this embodiment, draft loss can be reduced because perforated plates are arranged at necessary locations.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent the gas flow exiting from the flue outlet from becoming uneven.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional vane type drift prevention device, FIG. 2 is a flow velocity distribution diagram of a gas flow along YY' shown in FIG. 1, and FIG. 3 is a configuration diagram showing an embodiment of the present invention. FIG. 4 is a block diagram of a conventional drift prevention device using a perforated plate method. 1... Vane, 3... Flue, 6... Perforated plate. Representative Patent Attorney Tatsuyuki Unuma Figure 1 Figure 2 Figure 3 Figure 4 Continued from page 1 Applicant Babcock Hitachi Co., Ltd. 2-6-2 Otemachi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] +11 In a drift prevention device that prevents drift at a curved portion of a flue connected to an inlet of a heat pipe, a plurality of vanes are provided at appropriate intervals in a portion of the flue curve where the radius of curvature is smaller than a predetermined value, and A drift prevention device characterized in that a perforated plate having the same area as a portion of the curved portion of the flue where the radius of curvature is larger than the predetermined value is provided at the flue outlet.