JP-7856316-B2 - System and method for preventing backflow in vertical rainwater drainage pipes with multiple lateral branches

Inventors

• ゴー、チュン ヒ
• アン、ギルバート

Assignees

• ファスト フロー リミテッド

Dates

Publication Date

20260511

Application Date

20210706

Priority Date

20200709

Claims (5)

1. A floor outlet for receiving water inflow, An outlet for connecting to a pipe, An inlet having an open outer opening for receiving water inflow and an open inner opening for releasing air, wherein the outer opening and the inner opening are in fluid communication with the insertion port, The entrance comprises an inner edge portion and an outer edge portion that define the inner opening and the outer opening, The inner opening is defined by the inner edge portion. The outer opening is a floor outlet, defined by the outer edge and the inner edge such that the inner opening is located within the outer opening and the inner edge is common between the outer opening and the inner opening.
2. The floor outlet according to claim 1, further comprising a chamber located midway between the insertion port and the opening, wherein the chamber has a larger cross-sectional area than the insertion port.
3. The floor outlet according to claim 2, wherein the chamber includes an upper part configured to receive air from the pipe and release the air to the inner opening, and a lower part configured to receive inflow from the outer opening and guide the inflow to the pipe.
4. The floor outlet according to any one of claims 1 to 3, wherein the outer edge and the inner edge are located on the same plane as the floor on which the floor outlet is located.
5. The chamber includes a canopy that covers the upper part of the chamber, The floor outlet according to claim 3, wherein the canopy forms a first conduit through which air flows from the insertion opening located below the front of the inlet to the inner opening, and the canopy forms a second conduit through which water flows from the front of the inlet to the rear of the inlet, thereby guiding the water flow through the rear of the inlet to the insertion opening.

Description

This invention relates to rainwater drainage for wind and rain spaces. In particular, it relates to downpipes and related branches used in high-rise buildings. Rainwater pipes with multi-stage lateral branching connections carry the risk of water backflow through the lateral branches. This risk is extremely difficult to predict under current gravity downspout design principles. The following are key factors that cause backflow in transverse bifurcations: - Releasing air trapped inside a pipe; - Unpredictability of two-phase flow characteristics when the flow rate increases beyond the safety limit that can maintain a clear separation between air and water. To prevent the aforementioned uncertainties, the flow rate of the vertical stack must be limited to a very small flow capacity. Many countries' rainwater drainage standards adopt the principle of not allowing the connection of horizontal branches to vertical roof drainage pipes to prevent backflow problems. At extremely low flow rates where water flow does not affect air flow, there is no risk of backflow. However, as the flow increases, the water density in the pipe increases. This increase in water flow affects the air inside the vertical pipe. As the downward water flow increases, additional air may be drawn in from the top of the vertical pipe (located on the roof) or from lateral branches located higher up in the stack. In cases where air drawn in with the water flow can move freely downwards and be freely discharged at the downstream end, such as through a pipe that discharges vertically into an open space, there is no risk of backflow. however, • Downstream, the pipe extends horizontally for a long distance. • An elbow exists downstream. In situations where air cannot freely flow out at the downstream end of a pipe, such as when flows from other stacks merge, or when the pipe discharge is submerged due to an overflow of an external drain, air will escape through the multi-stage lateral branch connection, particularly in the lower part of the stack. The air escaping through the lateral branching creates three problems. - It obstructs the effective flow of water to the floor outlet (which forms the entrance to the lateral branch). - It obstructs the effective flow of water through the lateral branch pipes. - The water flowing within the vertical stack is pushed out through the lateral branch, thus causing backflow. A first aspect of the present invention provides a branch pipe system for branching from a vertical pipe, the branch pipe system comprising a branch connection attached to the vertical pipe having a constricted cross-section forming a nozzle in the vertical portion, the nozzle comprising: a branch connection configured to increase the velocity head of water passing through the nozzle; an expansion chamber located directly below the nozzle and having a cross-sectional area larger than that of the vertical pipe; a branch portion protruding from the expansion chamber; a floor outlet; and a branch pipe connecting the branch portion to the floor outlet. A second aspect of the present invention provides a floor outlet for receiving water inflow, the floor outlet comprising a socket for connection to a pipe, and an inlet having two openings: a first opening for receiving water inflow and a second opening for releasing air, the inlet being in fluid communication with the socket. A third aspect of the present invention provides an elbow for providing an angled connection between two pipes, wherein the elbow has an inner radius and an outer radius, the inner radius being larger than the diameter of the pipes. A fourth aspect of the present invention provides an air release device to be attached to a pipe, the air release device comprising a housing defining a vertically oriented internal chamber, an opening at the base of the chamber for receiving air from the pipe, and a vent at the top of the chamber for releasing the received air, wherein the height of the chamber is greater than or equal to the width of the chamber. It would be convenient to further describe the present invention with reference to the accompanying drawings illustrating possible configurations of the invention. Other configurations of the invention are possible, and therefore, the details in the accompanying drawings should not be understood as negating the generality of the above description of the invention. This is an elevation view of a vertical pipe with a branch in the flow state of stage 2.This is an elevation view of a vertical pipe with a branch in flow states 3 and 4.This is a schematic elevation view of a vertical pipe and a horizontal branch.This is an elevation view of the joint according to one embodiment of the present invention.This is an isometric view of an elbow according to one embodiment of the present invention.This is an isometric view of the outlet according to one embodiment of the present invention.This is an air release device according to one embodiment