JPH0549779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a roof drainage method for draining rainwater accumulated on the upper surface of a roof to the outside.

[Problems to be solved by this invention]

Conventionally, as a drainage method for draining the upper surface of the roof of a building, the diameter of the drain pipe has been selected based on the concept of normal drainage described below.

The main water source for drainage in buildings is the removal of dirty water from sanitary appliances, and because the amount of water varies depending on the time of day, the flow is turbulent, irregular, and unsteady with large waves. Air is also present within the drainage system. The diameter of the drain pipe used for drainage must be selected in such a way that the water flowing down may create a positive or negative pressure difference with the atmosphere, causing the odor-preventing water trap on sanitary appliances to break. Prevent drainage from flowing backwards. At the same time, in order to prevent vibrations caused by friction between the water and air inside the pipe, the ratio of air to water in the wastewater flowing down the pipe is adjusted.
It is best to choose a flowing ratio of 6.5:3.5.

The diameter of the pipe was selected based on this concept of normal drainage, and it was believed that rainwater must be removed quickly to prevent it from accumulating on the roof, so the diameter of conventional rainwater drainage pipes was made thicker. There is.

Therefore, if the drain pipe is exposed outside the building, it will obstruct the view of the building, and if it is installed inside the building, the effective space of the building will be reduced due to the space required, and the construction cost will increase due to the large amount of labor required for piping work. There used to be many.

In addition, trash and sand can also flow into rainwater drainage and accumulate in the horizontal drainage pipes, so horizontal drainage pipes within buildings must be kept as short as possible. It required a lot of effort.

As described above, the conventional roof drainage method has many problems.

[Purpose of the invention]

This invention was devised in view of the above-mentioned circumstances, and its purpose is to eliminate the need to make the drain pipe thicker and to minimize the horizontal portion of the drain pipe inside the building. Moreover, it is an object of the present invention to provide a drainage method capable of surely draining rainwater accumulated on a roof surface.

[Means for solving problems and their effects]

This invention is arranged on a flat roof surface and
Rainwater is collected from multiple roof drains with a diameter that overflows when the amount of rainfall exceeds a certain amount into horizontal pipes installed on the underside of the roof drains, and from these horizontal pipes, the rainwater is guided to the drains via vertical pipes. In addition, rainwater overflowing on the roof surface is discharged outdoors from an overflow device having a drain opening above the roof drain opening and a vertical pipe provided separately from the vertical pipe. According to this method, rainwater drain pipes used for roof drainage of buildings are usually not connected to drain pipes from other drainage equipment, so there is no need to consider any obstruction caused by pressure differences within the drain pipes. It was created by focusing on the fact that there is no such thing.

Since the pressure inside the drain pipe does not change, rainwater is temporarily stored on the roof surface and the drain pipe is flushed with water, creating a suction effect inside the drain pipe. This is because when the water in the drain pipe is filled with water and flows down, the horizontal pipe and the vertical pipe become negative pressure due to the relationship between the position water head at a given height and the friction loss of the pipe wall, and the lower end of the vertical pipe becomes negative pressure. This is based on the principle that positive pressure is applied to the discharge part and the discharge part to the outside.

This suction action of the drain pipe promotes drainage of rainwater and the like within the drain pipe.

〔Example〕

The method of this invention will be explained below with reference to illustrative examples.

A plurality of roof drainage ports 2 are provided on a flat roof surface 1a of a building 1 and are formed to have a pipe diameter such that rainwater temporarily accumulates therein.

Further, inside the building 3, a drain pipe 7 is provided which is made up of a horizontal pipe 4 for collecting wastewater from the drain outlet 2, and a vertical pipe 6 leading from the horizontal pipe 4 to an external drainage groove 5. .

When the amount of rainfall exceeds a certain level, rainwater accumulates at the roof outlet 2, and when enough rainwater accumulates at the outlet 2 due to rain, air flows into the outlet pipe 7 that was being discharged mixed with air. is no longer mixed in and is completely filled with water.

When the inside of the drain pipe 7 is filled with water in this way, the horizontal draw pipe 4 under the roof slab 12 becomes negative pressure,
Unlike conventional general drainage, the flow does not flow naturally according to the downward slope, but instead flows downstream (vertical pipe) due to suction action.
The flow rate is high even in long horizontal pipes, and it removes sand and dust. Similarly, the vertical pipe 6 can also flow at a high flow rate.

In addition, because the suction action drains rainwater at a high flow rate, the rainwater accumulated on the roof will soon disappear. Therefore, if rain continues to fall at a constant rate exceeding a certain amount, accumulation and removal will occur repeatedly.

The depth at which rainwater accumulates in the roof outlet 2 is approximately 5 cm to 10 cm, and the diameter of the outlet 2 is selected to maintain this depth.

On the other hand, in order to allow rainwater to collect in the roof outlet 2, if we adopt the historical maximum rainfall of 60 minutes in the area, as with the conventional design rainfall intensity, normally almost no water will collect on the roof, so is not filled with water, so the suction action does not occur, and its effectiveness cannot be achieved.

Therefore, in this invention, if the 60-minute continuous design rainfall intensity is the normal amount of rainfall in the area, for example, the amount of rain that can occur once a year, the water will be discharged at full capacity several times a year, and the desired effect will not be met. It will be done. In that case,
For rainfall that exceeds the 60-minute continuous design rainfall intensity,
This problem can be solved by providing an overflow device 8.

This overflow device 8 includes a discharge port 9 provided on a surface a predetermined height higher than the discharge port 2, and a drain port 10 provided at a position where daily inspection is possible.
It consists of a vertical pipe 11 connecting the discharge port 9 and the drain port 10.

〔Effect of the invention〕

The present invention has the above configuration and has the following effects.

When rainfall exceeds a certain amount, the inside of the pipe becomes full of water and the flow of drainage can be promoted by the suction effect using the head, so the diameter of the drain pipe should be made much smaller than before. I can do it.

Therefore, when the drain pipe is installed outside the building, it looks good, and when installed inside the building, it requires less installation space. Furthermore, since the drainage pipe can be made lightweight, construction costs can be reduced.

Since the flow within the drain pipe can be forcibly promoted by the suction action, it is possible to increase the degree of freedom in design, such as by allowing horizontal draw pipes to be routed longer under roof slabs, etc.

[Brief explanation of the drawing]

The drawing is a schematic vertical sectional view showing a building employing the method of the present invention. 1...Building, 1a...Roof surface, 2...Roof outlet, 3...Inside building, 4...Horizontal pipe, 5...
Discharge groove, 6...vertical pipe, 7...discharge pipe, 8...overflow device, 9...discharge port, 10...drainage port, 11...vertical pipe, 12...roof slab.

Claims (1)

[Claims] 1. In the case of rainwater drainage from the roof of a building, rainwater is drained from multiple roof drains arranged on a flat roof surface and having a diameter such that they overflow when the amount of rainfall exceeds a certain level to horizontal drain pipes installed on the underside of the drains. is collected and led from this horizontal pipe to a drain via a vertical pipe, and from an overflow device with a drain opening above the roof drain, to a vertical pipe installed separately from the vertical pipe to the outside. A roof drainage method for a building, characterized by draining rainwater overflowing onto the roof surface.