Multiple Inlet flow regulator

Abstract

A multiple inlet flow regulator with a restricted low-level inlet and upper-level overflow inlet is used to modify a new or existing storm water catch basin to regulate the flow of storm water from the catch basin into the sewer system. During periods of heavy rains and high flows into the catch basin, this flow regulator will allow the catch basin to serve as a temporary storage tank for storm water. The construction of these flow regulators can be accomplished using a variety of off-the-shelf components or custom fabrication, to achieve the desired effect of restricting the discharge from each catch basin in a combined sewer or storm water system as much as practicable without resulting in overflows onto the roadways. Key components include: restricted low level inlet that can be adapted in size to meet specific low flow conditions, upper level inlet sized to allow for the maximum discharge from the catch basin to prevent overflows onto the roadway, connections to the existing catch basin structure and covers to prevent floatable debris from discharging from the catch basin into the sewer system.

Description

REFERENCES

U.S. Patent Doccuments
	5,080,137	January 1992	Adams . . . 137/810

This invention relates to a multiple inlet flow regulator used in storm water catch basins to regulate the discharge of storm water from the catch basins to reduce the impact to the drainage system that could result in overflows or other negative impacts to the drainage system.

The multiple inlet flow regulator works due to the basic principals of fluid flow including head pressure and flow through an orifice. No mechanical or moving parts are required for this device. Multiple inlet flow regulators are attached in front of the discharge pipe of a new or existing storm water catch basin and are responsive to the rate of flow into and out of the catch basin due to storm water runoff. Flow regulation using this device is achieved in three different phases:

Stage 1) Low intensity rain events, where flow into the catch basin is relatively low, all of the flow into the basin will be discharged out of the low level outlet. Due to the low intensity there is no need to regulate the storm water flow out of the catch basin into the sewer collection system.

Stage 2) During moderate rain events, where the runoff is increased to a level requiring flow regulation, the hydraulic restriction of the low level outlet will regulate the storm water discharge out of the catch basin. This regulation of flow will help prevent the downstream sewer system from receiving flows beyond the system capacity that could result in an overflow. As the discharge flow is regulated, the basin will retain the excess storm water at an elevation above the low level outlet. As the volume of storm water retained increases, the discharge rate will increase due to the increasing head pressure.

Stage 3) During intense rain events, the runoff entering the catch basin will exceed the capacity of the low level outlet and the depth of storm water stored in the basin will increase to the level of the upper level outlet. When this occurs all of the additional flow beyond the volume stored between the low level outlet and the upper level outlet will be discharged through the upper level outlet. This outlet is sized in conjunction with the low level outlet to achieve the same flow volume as the catch basins discharge piping, i.e. the addition of the multiple inlet flow regulator will not increase the potential for a catch basin to overtop allowing storm water to spill onto the roadway.

The inlet structures of the multiple inlet flow regulator are shielded to prevent floatable debris from entering the device and from discharging from the catch basin. These shields serve two functions: to prevent the device from clogging and to prevent debris from entering the collection system.

The flow characteristics associated with the multiple inlet flow regulator can be calculated using standard hydraulic analysis formulas familiar to civil or hydraulic engineers, including the Chezy-Manning Equation:

$V={\frac{k}{n}\left[\frac{A}{P}\right]}^{2/3}\times S^{1/2}$ $V=\mathrm{Velocity}\mathrm{in}\mathrm{ft}\text{/}s$ $k=1.486\left(\mathrm{constant}\right)$ $n={\mathrm{Manning}}^{\prime }s\mathrm{roughness}\mathrm{coefficient}$ $n=0.014\mathrm{for}\mathrm{concrete}\mathrm{pipe}$ $n=0.011\mathrm{for}\mathrm{PVC}\mathrm{pipe}$ $A=\mathrm{Area}$ $P=\mathrm{Wetted}\mathrm{perimeter}$ $S=\mathrm{Slope}$

and a modification of Bernoulli's Equation:

V=C _v(2gh)^1/2

• • C_v=Orifice coefficient
  • g=gravitational constant (32.2 ft/s²)
  • h=Hydraulic head in feet

Velocity is converted into flow volumes using the Continuity Equation, Q=V*A.

• • Q=Flow in cubic feet per second (CFS)
  • V=Velocity in feet per second
  • A=Area in square feet

It is the principal object of this invention to provide a cost effective, simple solution reduce combined sewer overflows and other negative impacts associated with the rapid discharge of storm water from catch basins. Multiple inlet flow regulators can be mass produced and installed in a variety of existing application by semi-skilled workers without the need for specialized tools or training.

Another object of this invention is to provide a device that can be adapted to various system constraints including: desired low level outlet discharge, different catch basin structures (circular or rectangular), variations in catch basin depth and outlet piping configuration.

Another object of this invention is to allow the catch basin to drain after the storm subsides so there are no issues associated with a basin “holding” excess water above the catch basin sump (risk of drowning, insects, system is ready for the next storm).

For a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a vertical sectional view of a storm water runoff catch basin with a multiple inlet flow regulator according to one form of the invention installed in front of the discharge pipe thereof.

FIG. 2 is a horizontal sectional view of a storm water runoff catch basin with a multiple inlet flow regulator, taken on line 2-2 of FIG. 1 according to one form of the invention installed in front of the discharge pipe thereof.

FIG. 3 is a vertical view of the front of the invention, taken on line 3-3 of FIG. 1 according to one form of the invention installed in front of the discharge pipe thereof.

FIG. 4 is a vertical sectional view of one form of the invention taken along line 4-4 of FIG. 2. Arrows indicating the flow path of the storm water through the invention have been included in this view to demonstrate how the invention will work.

FIG. 5 is an enlarged and exploded side view of one form of the invention showing the component parts.

FIG. 6 is an enlarged and exploded front view of one form of the invention showing the component parts.

FIG. 7 is an enlarged horizontal sectional view of the vertical riser section (4).

FIG. 8 is an enlarged horizontal view, taken along line 8-8 of FIG. 5, depicting the low level inlet control section (1).

FIG. 9 is an enlarged view, taken along line 9-9 of FIG. 5, depicting the low level inlet control section (1).

FIG. 10 is a vertical sectional view a storm water runoff catch basin with an alternate form of the invention shown in front of the discharge pipe of the storm water catch basin.

FIG. 11 is a vertical section view of an alternate form of the invention taken along line 11-11 of FIG. 10.

FIG. 12 is a graph comparing to discharge rate over time from either a single catch basin or a series of catch basins showing the reduction in peak discharge rates achieved with this invention.

DETAILED DESCRIPTION

Referring to the first form of the invention shown in FIGS. 1 to 9, inclusive, 11 represents a catch basin for the collection of storm water runoff built from either pre-cast concrete or concrete block. This catch basin 11 includes a base 14, vertical walls 13 where the walls can either be rectangular in section or circular (drawings here are shown with a rectangular configuration), a top section 28 that contains an opening 29 for storm water to enter the basin and a metal grate 12 that fits into the opening 29. Such catch basins have an outlet or discharge pipe 14 that connects to a storm water collection system or a combined sewer system.

Contained with in the catch basin 11, a multiple inlet flow regulator comprised of four pieces, 1 the low level inlet cap, 7 the unit base section, 4 the riser section, and 5 the upper inlet cap.

The low level inlet cap 7, has five components to this individual piece: the 2 inlet screen, 3 inlet shield, 18 orifice opening, 19 cap gasket, and 30 cap section. The 2 inlet screen is a curved screen with openings to allow storm water to enter into the device, but the curved screen is designed to keep floatables from entering into the device and to prevent debris from collecting on this screen that could lead to clogging of the device. The inlet screen 2, is connected to the 3 inlet shield and 30 the cap section. The inlet shield 3 supports and provides rigidity to the inlet and prevents floatables from entering into the device. The cap section 30 is similar in shape an function to a standard PVC pipe end cap. The cap section is a flat plate with flanges that contain the cap gasket 19 to allow for a tight seal with the base unit 7. The cap gasket 19 allows for a water tight connection with the base unit. The cap gasket is fused to the cap section flanges. Within the flat plate of the cap section 30 is the orifice opening 18 that allows a restricted volume of water to enter the invention through the low level inlet. The size of the orifice opening will vary upon the desired flow restriction based on specific requirements for the application.

The base unit 7, has 3 component parts that connect to this unit: the 6 base unit gasket, 8 mounting flange, and 31 the base unit inlet flange. The base unit is connected to the low level inlet cap 1 and the riser section 4. The connection to the riser section is made using a flared opening in the top of the base unit that contains the base unit gasket 6 that allows for a water tight connection. The base unit is connected to the catch basin wall 13 using the mounting flange 8 that covers the perimeter of the base unit. The mounting flange can be bolted into the wall using expansion bolts 9, or connected using other methods such as epoxies or other adhesives. The base unit flange 31 is a circular flange that allows for a connection with the low level inlet cap 1.

The riser section 4 is the simplest of the components of this form of the invention. This section is a generally rectangular in section with mounting flanges 8 for connection to the catch basin walls 13. The connection of the flanges would be accomplished as described for the base unit 7, using expansion bolts or adhesives. The riser section is intended to be cut to length in the field during installation, allowing for the necessary adjustments for catch basins of varying depths.

The upper inlet cap 5, is comprised of an inlet screen 10, mounting flange 8 and a lower frame 32. The lower frame 32 is connected to the mounting flange 8 to allow for a frame to support the inlet screen 10 to be at an angel. The inlet screen is designed to allow storm water to enter into the invention though this screen; this is the upper level inlet. The inlet screen 10 is intended to prevent floatables from entering the invention and to prevent clogging. The angle of the screen will allow floatables to roll off and fall to the bottom of the catch basin with the water level in the basin subsides.

Referring to the second form of the invention shown in FIGS. 10 to 11, inclusive, 11 represents a catch basin that connects to a storm water collection system or a combined sewer system for the collection of storm water runoff as previously described above. This form of the invention is intended to demonstrate that a multiple inlet flow regulator can be constructed using standard “off-the-shelf” piping commonly found in the storm water and/or sewer industry. This form of the invention as shown in FIGS. 10 and 11 is representative of how standard piping can be used, but there are many other variations on the use of off-the-shelf piping.

The primary components of this form of the invention are all PVC piping and include: 21 tee, 22 piping for riser section, 22 piping for connection, 27 upper inlet screen, 19 end cap, 20 elbow (90-degree) for low level inlet, 25 metal strapping for connection to catch basin walls, 26 expansion bolt for connection to catch basin walls, 16 metal band clamp for attach upper inlet screen and 22 rubber O-rings for connection to existing outlet pipe. This configuration of the invention uses a short section of piping 22 in conjunction with o-rings 22 to make a connection into the catch basin discharge pipe 14. The short section of piping 22, and the other components would be one standard pipe size smaller than the discharge pipe 14 to allow the components to fit together and to use the o-rings for the connection with the discharge pipe 14. The end cap 19 is a standard product that would need to be modified as shown in FIG. 11. The modifications would include drilling an orifice hole 18, and attaching 20 an inlet shield consisting of a 90-degree elbow. This inlet shield would prevent most floatable from entering the invention. The inlet shield 20 can be connected to the end cap using an epoxy or other adhesive. The modification to the end cap 19 would be the only modification to standard off-the-shelf components necessary to make this form of the invention.

Claims

1. A multiple inlet flow regulator adapted for use in a storm water catch basin having a low level inlet with an orifice sized to the individual catch basins requirements in a given storm water or combined sewer system with said orifice designed to regulate the discharge of storm water out of the catch basin as to extend the time required for the storm water entering the basin to discharge from the basin into the storm water or combined sewer system, thereby allowing the catch basin to act as a temporary retaining structure. The result of the flow regulation is a reduction in the peak discharge from both individual catch basins and systems of catch basins as shown in FIG. 12.

2. A multiple inlet flow regulator adapted for use in a storm water catch basin as described in claim 1 with an upper level inlet to limit the level of storm water retained in the basin to prevent the basin from overtopping and flooding the surface above the catch basin structure.

3. A multiple inlet flow regulator adapted for use in a storm water catch basin as described in claim 1 with a low level inlet screen to prevent clogging and floatables in the catch basin structure from discharging into the storm water or combined sewer system.

4. A multiple inlet flow regulator adapted for use in a storm water catch basin as described in claim 1 with a upper level inlet screen to prevent clogging and floatables in the catch basin structure from discharging into the storm water or combined sewer system.