JPH08338585A - Converging pipe for two-layered pipe duct - Google Patents

Abstract

PURPOSE: To enhance the ventilating capacity of a converging duct for an indoor ventilation, by using a curved part having a diameter which is arcuately enlarged at a constant rate for a right angle bent part which extends from a connecting part of a second duct entering the converging part at a right angle thereto, to a connecting part of an outer layer duct of a two-layered pipe. CONSTITUTION: A converging pipe in which a first duct 2 for ventilating hot air from a bath room is converged to a second duct 3 for ventilating malodor from a toilet at its intermediate part so as to vent the air outside, incorporates a two layer pipe 4 composed of an outer layer duct 41 and an inner layer duct 42. Further, the converging pipe 1 is the integral combination of an insertion part 14 for horizontally receiving and supporting the first duct 2, a curved pipe part 13 fitted thereonto with one end of the second duct 3 and curved up to a horizontal direction so that the direct extension of the first duct 2 serves as an inner duct 42. The curved pipe part 13 is curved while its diameter is gradually increased at a constant rate, thereby it is possible to decrease the internal resistance of the pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust duct for indoor piping such as household and business use.

[0002]

2. Description of the Related Art Considering exhaust gas in a house, for example,
In recent years, it has become an important factor to set up multiple exhaust systems indoors for comfortable living. In modern houses, rooms are separated according to their functions based on the progress of electrification and rational room allocation, and the exhaust (sometimes air supply) required to prevent the deterioration of each environment is provided individually. It has become a normal need. For that at least the bathroom,
Terminals of ducts open in toilets, washrooms, kitchens, etc., and blowers are attached to suck in hot air and odors around them.
Duct piping that discharges to the outdoors through the pipeline is an essential accessory facility.

In a single-family house or a condominium such as a condominium, there are a plurality of places where exhaust air is required. Therefore, it is natural that each duct end is opened to the place where it is generated, but each duct is a separate pipe line. If it is installed in, the number of piping man-hours at the time of construction will increase, and it can be considered as one of the causes of the high construction cost. Moreover, since the piping uses an invisible ceiling and the like to enhance the aesthetics of the interior, it can only fill a fairly narrow space, and it is restricted to very limited conditions to accommodate a complicated pipeline. I have to be done.

The technique devised to overcome this technical difficulty is the idea of a double layer tube. FIG. 6 is a perspective view for explaining the basic structure of a two-layer pipe, in which a first duct 2a piped from one direction and another second duct 3a orthogonal to this direction merge to form an outer layer duct. A two-layer pipe 4a composed of 41a and an inner layer duct 42a is formed. In the example of this figure, the first duct serves as the exhaust from the bathroom and the second duct serves as the exhaust from the toilet / washroom, but in any case, in the past, separate ducts were used for scanning. By consolidating indoor piping into one duct, the volume occupied in the space is halved, and the man-hours required for construction are almost halved, which simplifies the design and saves the construction cost.
It is evaluated that the advantages such as shortening the construction period are remarkable.

FIG. 7 is a plan view showing two examples of a confluent pipe that has been conventionally used in the confluent portion of a two-layer pipe. FIG. 7 (A)
In the figure, the first duct 2b traveling in the horizontal direction is a conduit for discharging hot air in the bathroom, and the second duct 3b orthogonal thereto is a conduit for discharging odor and hot air from the toilet / washroom.
In this form, both ducts consist of straight pipes of almost the same outer diameter until they merge, and a spiral duct in which a long zinc-iron plate is spirally wound and its end faces are engaged with each other, and a stainless steel pipe are used. A straight seam pipe or a PVC coating pipe is used as the pipe material. However, in order to merge and form the two-layer pipe 4b, both ducts cannot be formed with the same outer diameter. Therefore, one duct is expanded and the other duct is crowned at an equal distance to form an annular shape. A peripheral conduit must be formed. In the case of this figure, the second duct 3
Before the b is connected to the confluence pipe 1b, the outer diameter is expanded and the diameter is increased to enter the confluence pipe, and the first duct having the pipe diameter before the confluence is used as the inner layer and the crown is expanded and crowned. The second duct serves as an outer layer and merges to form a double-layered pipe.

FIG. 7B shows another embodiment of the confluence pipe 1c. The second duct 3c enters the confluence pipe 1c while maintaining the outer diameter as it is, and is bent into a T-shape inside the confluence pipe. In addition, the diameter is increased and the diameter is connected to the outer layer duct 41c of the two-layer pipe 4c. In both (A) and (B), the advancing direction of the second duct is changed to a right angle, and the point that the diameter is expanded and crowned on the outer periphery of the first duct to form an annular outer layer duct with a constant width. , It has an unavoidable basic structure of a confluence pipe.

[0007]

The above two conditions are unavoidable basics, but in this case, a merging pipe is inserted in the middle of a long pipe, and the diameter is expanded before connection. Since the structure is such that the direction of travel is bent at a right angle, or it is bent at a right angle in the confluence pipe after connection and expands at the same time, it is a typical turbulence phenomenon when moving as an air flow path. As a result, a very large fluid resistance is generated, which is likely to be one of the main causes of deterioration in the ability to discharge the target gas through a long conduit. If the capacity of the ventilation fan attached to the tip of the exhaust port is constant, it goes without saying that the greater the fluid resistance, the lower the effectiveness of the exhaust, and it may be one of the obstacles that hinder the results of rational pipe rationalization. Can not be wiped.

In order to solve the above-mentioned problems, the present invention provides a merging pipe whose fluid resistance is reduced to the utmost, while following the basic structure which fulfills the conditions in the merging portion for forming a two-layer pipe. With the goal.

[0009]

A merging pipe 1 of a two-layer pipe duct according to the present invention enters in the middle of a first duct 2 forming an exhaust pipe line from one direction while intersecting at right angles to the direction. The second duct 3 joins, and is subsequently used at the joining portion of the two-layer pipe 4 composed of the outer layer duct 41 which is crowned at an equal distance on the outer circumference of the inner layer duct 42 which is an extension of the first duct 2. Then, a bent pipe portion 13 in which a right-angled bent portion extending from the connecting portion 11 of the second duct 3 which enters the merging portion from the perpendicular direction to the connecting portion 12 of the outer layer duct 41 of the two-layer pipe 4 is constantly expanded with an arc. The above-mentioned problem was solved by forming by.

[0010]

In the merging pipe of the present invention, after the second duct enters, it gradually bends over the entire path leading to the outer layer duct of the two-layer pipe while gradually expanding at a constant rate and bends, so that a flow state due to turbulent flow occurs. The adverse effect of is reduced, and the resistance to air movement in the tube is significantly reduced as compared with the prior art. The decrease in resistance reduces the rate of deterioration of the exhaust function, and the prior art is clarified by comparing the case where the merge pipe according to the present invention and the conventional merge pipe (for example, FIG. 7) are applied to form the same pipe series. Exhaust action that surpasses that is expressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a confluence pipe 1 showing an embodiment of the present invention, and FIG. 2 is a plan view illustrating a piping system in which an embodiment of the present invention is constructed. First duct 2 and second duct 3
As for the two-layer pipe 4 after joining, it is sufficient to apply a conventional piping material, and in this example, a spiral pipe made of a zinc-plated steel sheet having a thickness of 0.6 mm was used. The exhaust points are the bathroom and the toilet, and the first duct 2 for exhausting the hot air in the bathroom and the second duct 3 for exhausting the odor in the toilet join together in the middle, and the outer layer duct 41 of the two-layer pipe 4 and the inner layer duct 42. Is emitted from an exhaust port (not shown) that is combined with the above and opens to the outside.

Since the first duct 2 of the merging pipe 1 extends as it is as shown in FIG. 1 to form the inner layer duct 42 of the two-layer pipe 4,
Insertion part 14 for horizontally inserting and supporting the first duct 2
And a curved pipe portion 13 that is fitted outside the pipe end of the second duct 3 and bends and expands while becoming horizontal, and is integrally combined. The outer diameters of the first and second ducts up to the confluence pipe are both 100 mm, but the first duct 2 is extended as it is to become the inner layer duct 42 of the two-layer pipe 4 having an outer diameter of 100 mm, and the second duct 3 is joined. After being externally fitted to the connecting portion 11 of the pipe 1, the connecting portion 12 of the outer layer duct 41, which is bent and expanded in diameter and turned at a right angle, is expanded to 150 mm in diameter. That is, in the two-layer pipe 4, the hot air from the bathroom moves inside the pipe of the inner-layer duct 42 having a diameter of 100 mm,
The odor from the toilet moves and is discharged in the annular space of the doughnut-shaped outer layer duct 41 having an inner diameter of 100 mm and an outer diameter of 150 mm, which is superposed on the outer circumference of the toilet.

In this embodiment, the shape of the merging pipe 1 can be divided vertically symmetrically with respect to the plane of the paper of FIG. 1. Therefore, after half-forming by sheet metal bending with a press, the end faces of both can be welded together for easy integration. This is a form that can be recommended because it has many advantages such as economic advantages due to mass production, easy prevention of welding defects due to shortening of welding line, and maintaining reliable airtightness.

The variation of the fluid resistance of the merging pipe is measured by this embodiment, and one example of the effect of the present invention will be concretely proved in comparison with the merging pipe of the prior art measured under the same conditions. FIG. 3 is a plan view showing an arrangement for actual measurement, and an end of the first duct 2 made of a spiral steel pipe is not shown.
A blower B is attached to the end of the second duct 3 made of a spiral steel pipe having a diameter of 100 mm and a cross-sectional area A ₁ , and a pitot pipe P is inserted at a position U between the merging pipe 1 and the duct center wind speed u / dynamic pressure. In addition to measuring P _v0 , the static pressures P _{s1 to} P _{s4 at} the measurement points before and after that are also measured. The confluence pipe 1 is a two-layer pipe 4 ahead, and it is provided at a distance from each other in an annular outer peripheral duct having a cross-sectional area A ₂ formed by an outer layer duct 41 having a diameter of 150 mm and an inner layer duct 42 having a diameter of 100 mm. The static pressures P _{s5 to} P _s8 at the measurement points are measured.

From the dynamic pressure P _{v0 at the} position U to the second duct 3
Dynamic pressure P _v1 inside and the dynamic pressure P _v2 of the annular outer peripheral passage in the double-layer pipe 4.
And are respectively calculated by the following formulas (1) and (2),
By summing this dynamic pressure and the actually measured static pressure, the total pressure P _{t at} each position is calculated.

[0016]

[Equation 1]

[Equation 2]

Table 1 shows the measured values at the respective measurement points shown in FIG. 3 and the results calculated by the above mathematical formulas (1) and (2) based on the measured values. The static pressure, the dynamic pressure and the total pressure are shown in Table 1. When the relationship is plotted for each measurement point, it is shown as a combined pressure fluctuation diagram of actually measured static pressure and calculated dynamic pressure as shown in FIG. That is, since the vertical line standing up to the measurement point in FIG. 4 corresponds to the position of the merging pipe 1, the step of the total pressure before and after this corresponds to the pressure loss ΔP _t generated in the merging pipe. Table 2 is Table 1
Different from the spiral steel pipe duct of No. 1, the data of the same measurement test is applied when a straight seam pipe (simple cylindrical pipe) is applied, and FIG. 5 is a pressure fluctuation diagram in which the measured static pressure and calculated dynamic pressure are combined. .

[0018]

[Table 1]

[Table 2]

When ΔP _t can be calculated, the local resistance coefficient ζ in the pipe can be calculated from the equation (3), and the equivalent length L of the pressure loss can be calculated from the equation (4). However, the friction loss ΔP per 1 m of double-layer pipe is 86 mm in diameter when the inner-layer duct is a spiral pipe and 95 m in diameter when the inner-layer duct is a spiral seam pipe.
m was calculated from a friction loss chart of a duct (not shown).

[0020]

(Equation 3)

[Equation 4]

Table 3 summarizes the results of this calculation.
The average local resistance coefficient ζ and the equivalent length L in this actual measurement test are 1.70 and 0.53 for the spiral steel pipe and 1.76 and 0.5 for the straight seam pipe, respectively.
It was confirmed to be 0. Figure 7 measured under the same conditions
When the conventional techniques shown in (A) and (B) are listed as Comparative Example 1 and Comparative Example 2, respectively, the results are shown in the lower column of Table 3, and it is proved that there is a noticeable gap between the two.

[0022]

[Table 3]

[0023]

The confluence pipe of the two-layer pipe according to the present invention has a resistance coefficient reduced to 1/2 to 1/4 as compared with the confluence pipe according to the prior art as shown in one example in the embodiment. It was also proved that the equivalent length was shortened by about 1/2 to 1/4, and at that ratio, the pressure loss was small and the exhaust capacity was improved. It goes without saying that this effect is induced by the action in which the flow of the air flow in the bent portion is much smoother than in the conventional technique and the generation of vortices is small.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a plan view of construction to which the embodiment of the present invention is applied.

FIG. 3 is a plan view of a test arrangement for actually measuring pressure loss for confirming the effect of the present invention.

FIG. 4 is a pressure fluctuation diagram in which a measured static pressure and a calculated dynamic pressure are combined. (Spiral steel pipe)

FIG. 5 is a pressure fluctuation diagram in which a measured static pressure and a calculated dynamic pressure are combined. (Straight seam tube)

FIG. 6 is a perspective view showing a general two-layer pipe structure of the prior art.

7 (A) and 7 (B) are plan views exemplifying different confluence pipes of the prior art.

[Explanation of symbols]

 1 Combined pipe 2 First duct 3 Second duct 4 Two-layer pipe 11 Connection part (second duct) 12 Connection part (two-layer pipe outer layer duct) 13 Curved pipe part 14 Insertion part (first duct) 41 Outer layer duct 42 Inner layer Duct B Blower P Pitot tube ζ Local resistance coefficient L Equivalent length

Claims (1)

[Claims] 1. A first duct 2 forming an exhaust pipe from one direction is joined with a second duct 3 which intersects at a right angle with the first duct 2 and joins. In the two-layer pipe 4 in which the outer layer ducts 41 are formed on the outer circumference of the inner layer duct 42 at equal distances from each other, the merging pipe 1 used for the merging portion enters the merging portion from the right angle direction. The bent portion at a right angle from the connection portion 11 of the two-duct 3 to the connection portion 12 of the outer-layer duct 41 of the two-layer pipe 4 is
A confluent pipe of a two-layer pipe duct, characterized in that it is formed by a curved pipe portion 13 whose diameter is expanded at a constant rate with an arc.