Crossflow settling device and method of use

Abstract

The stormwater treatment device can include a cross-flow settling device having a treatment channel defined by a front baffle, a rear baffle, and a pair of inclined plates disposed at complementary angles between the front baffle and the rear baffle, the front baffle having a treatment channel opening, and the rear baffle having a treatment channel outlet. Under normal flow, stormwater flows into the inlet and into the inlet chamber, through the treatment channel opening into the treatment channel, through the treatment channel outlet into the outlet chamber in a cross-flow pattern, causing sediment to fall out of suspension and flow out of the cross-flow settling device through openings in the bottom of the pair of inclined plates.

Description

Technical Field

[0001] This disclosure generally relates to crossflow settling devices and methods of using them. Background Technology

[0002] When it rains, rainwater passes over various surfaces before reaching the sewers. Along the way, rainwater picks up and suspends natural and man-made pollutants, carrying them into the sewers. The sewers provide an initial opportunity to remove some of these pollutants from the rainwater before it flows into water bodies. Summary of the Invention

[0003] The crossflow settling device and its usage method have been disclosed.

[0004] According to an embodiment, a rainwater treatment device may include a housing having a bottom plate and walls; an inlet formed in the walls that receives rainwater, including suspended sediment, into an inlet chamber of the housing, the inlet chamber being defined by a first portion of the walls and a front baffle extending vertically from the bottom plate of the housing; an outlet formed in the walls that discharges rainwater from an outlet chamber of the housing, the outlet chamber being defined by a rear baffle, a second portion of the walls, and a short-circuit protection plate; and a treatment chamber and a sediment storage area defined by the front baffle, a third portion of the walls, the rear baffle, and the short-circuit protection plate, and wherein a crossflow settling device is disposed therein, the crossflow settling device having a treatment channel defined by the front baffle, the rear baffle, a first pair of inclined plates placed on a first side of the housing centerline, and a second pair of inclined plates placed on a second side of the centerline, the first pair of inclined plates and the second pair of inclined plates being arranged at complementary angles, the first pair of inclined plates and the second pair of inclined plates being placed between the front baffle and the rear baffle, the front baffle having a treatment channel opening, and the rear baffle having a treatment channel outlet. Under normal flow conditions, rainwater flows into the inlet and enters the inlet chamber, enters the treatment channel through the treatment channel opening, and enters the outlet chamber through the treatment channel outlet. The rainwater flows in a cross-flow manner, causing sediments to fall from the suspension and flow out of the cross-flow settling device through the openings at the bottom of the paired inclined plates.

[0005] In one embodiment, the rainwater treatment device may further include a bypass channel comprising an inlet weir, an outlet weir, and a pair of bypass channel walls, wherein the height of the top of the inlet weir is the same as the height of the gap in the outlet weir between the bypass channel walls, but lower than the height of the top of the outlet weir outside the bypass channel, and lower than the height of the bypass channel walls, wherein when the flow exceeds a limit, the bypass channel receives a flow exceeding that of the inlet weir, thereby bypassing the treatment chamber and the sediment storage area.

[0006] In one implementation, at high flow rates, rainwater flows over the inlet weir and either enters the bypass channel, then flows through a gap in the outlet weir and into the outlet chamber, and exits the shell through the outlet, or enters the floatable material retention area between the bypass channel wall and a third section of the wall.

[0007] In one implementation, the complementary angle can be between about 45 / 145 degrees and about 65 / 115 degrees.

[0008] In one implementation, the width of each plate may be less than the length of the plate.

[0009] In one implementation, the spacing between the pairs of plates can be between 1 and 4 inches.

[0010] According to another embodiment, a method for removing suspended sediments from rainwater may include: (1) receiving rainwater containing suspended sediments at an inlet in the wall of a rainwater treatment device having a housing having a bottom plate and walls, wherein rainwater flows into an inlet chamber defined by a first portion of the walls and a front baffle extending vertically from the bottom plate of the housing; (2) receiving rainwater containing suspended sediments in a treatment chamber defined by a front baffle, a second portion of the walls, a rear baffle, and a bypass plate, the treatment chamber having a crossflow settling device disposed therein; (3) receiving rainwater containing suspended sediments by the crossflow settling device having a front baffle, a rear baffle, and a first baffle disposed on a first side of the centerline of the housing. The treatment channel is defined by a pair of inclined plates and a second pair of inclined plates placed on the second side of the centerline. The first pair of inclined plates and the second pair of inclined plates are set at complementary angles. The first pair of inclined plates and the second pair of inclined plates are placed between a front baffle and a rear baffle. The front baffle has a treatment channel opening and the rear baffle has a treatment channel outlet; (4) Rainwater is allowed to flow in a crossflow mode through the crossflow settling device at a normal flow rate, so that the sediment falls from the suspension and flows out of the crossflow settling device through the opening at the bottom of the pair of inclined plates; (5) Rainwater with some sediment removed is received in the outlet chamber defined by the rear baffle, the second part of the wall and the anti-short circuit plate; and (6) Rainwater with sediment removed is discharged through the outlet in the third part of the wall.

[0011] In one embodiment, the method may further include receiving rainwater carrying sediment into a bypass channel at high flow rates. The bypass channel includes an inlet weir, an outlet weir, and a pair of bypass channel walls. The height of the top of the inlet weir is the same as the height of the top of the gap in the outlet weir, and lower than the height of the top of the outlet weir and the top of the bypass channel walls. When the flow rate exceeds a limit, the bypass channel receives the flow through the inlet weir, thereby bypassing the treatment chamber and sediment storage area. The rainwater carrying sediment flows through the inlet weir and into the bypass channel, and through the gap in the outlet weir and into the outlet chamber, exiting the shell through the outlet. In one embodiment, at high flow rates, some rainwater flows through the inlet weir and into a floatable sediment retention area between the bypass channel walls and a third portion of the walls.

[0012] In one implementation, the floatable object may be held in a floatable object holding area.

[0013] In one implementation, at very high flow rates, floatable material can overflow the outlet weir and bypass channel walls and enter the outlet chamber.

[0014] In one implementation, the complementary angle can be between about 45 / 145 degrees and about 65 / 115 degrees.

[0015] In one implementation, the width of each plate may be less than the length of the plate.

[0016] In one implementation, the spacing between the pairs of boards can be between about 1 inch and 4 inches.

[0017] In one embodiment, the water treatment apparatus can receive water (such as rainwater containing suspended sediment) into an inlet chamber. The inlet chamber may include one or more diverters that direct all water flow reaching a specified treatment flow rate into a treatment zone of the treatment chamber. The water can then flow into the treatment zone of the treatment chamber, which includes a crossflow device comprising one or more pairs of parallel plates with complementary angles between, for example, about 45 / 135 degrees and about 65 / 115 degrees, and a gap between the tops of the plates, suspended between two opposing, spaced-apart, substantially vertical weirs. Water can flow across the plates in a crossflow pattern, and water can flow out of the treatment chamber into an outlet chamber.

[0018] In one embodiment, the plates may have an axis of symmetry parallel to the length of the plates.

[0019] In one embodiment, the length of the board may be greater than or equal to about four feet, the width of the board may be less than the length of the board, and the spacing between the boards may be between about one and four inches.

[0020] In one implementation, water exceeding a specified flow rate can flow through an inlet chamber and over the top of a treatment chamber, which includes a weir system designed to retain floatable debris at flow rates above the treatment flow rate and below the excessive bypass flow rate. The weir can form a central trough, for example, approximately two to three feet wide, and can be positioned in the wall between the treatment chamber and the outlet chamber, extending the width of the outlet side. For example, the top of the weir can be at least approximately 18 inches higher than the top of the inclined plate. Gaps can be provided in the weirs on the inlet and outlet sides of the trough, these gaps being below the top of the sides of the trough and the wall on the outlet side. Water can enter the trough at a flow rate above the design treatment flow rate but below the excessive bypass flow rate and be directly conveyed to the outlet chamber.

[0021] In one embodiment, the captured sediment can be stored on the floor plate of the chamber. A baffle can be provided between the inlet chamber and the treatment chamber, and the baffle can extend from the bottom of the inclined plate to the floor plate of the vault to prevent the stored sediment from moving from the inlet chamber to the treatment chamber. A second baffle can extend between the sediment chamber and the outlet chamber to the floor plate of the vault or to the rear wall of the chamber to prevent the stored sediment from moving from the treatment chamber to the outlet chamber.

[0022] According to another embodiment, the separator assembly may include an inclined unit separator having a plurality of rectangular plates placed between opposing, spaced-apart, substantially vertical weirs. The plates have opposing, elongated top and bottom edges and a front and rear surface therebetween. The plates have an inclined direction relative to a vertical axis. The plates are arranged in pairs at complementary angles. There is an axis of symmetry between the plates parallel to the plate length. The inclined direction forms inclined units between the plurality of adjacent plates. The weirs include substantially parallel inlet and outlet weirs having opposing top and bottom edges and a front and rear surface therebetween.

[0023] The inclined unit separator is located within a chamber formed by opposing end walls, opposing side walls, a top, and a bottom. The opposing end walls include an inflow wall having an inflow opening therein and an outflow wall having an outflow opening therein. An inlet weir and an outlet weir extend between the opposing side walls of the chamber. There is an inflow chamber between the inflow wall and the inlet weir. There is an outflow chamber between the outlet weir and the outflow wall. There is also a sediment collection area along the bottom of the chamber below the inclined unit separator and between the inflow chamber and the outflow chamber.

[0024] In one embodiment, the inclined plates may be arranged in pairs at complementary angles, with the complementary angles ranging from about 45 / 135 degrees to about 65 / 115 degrees, and the distance between the tops of the plates is at least about four inches.

[0025] In one embodiment, the length of the plate in the flow direction may be greater than or equal to about four feet, the width of the plate may be less than the length of the plate, and the spacing between the plates may be between about one and four inches.

[0026] In one embodiment, the bottom edge of the first weir may extend to the bottom of the chamber, and a portion of the top edge of the weir may be at the same level as the top of the unit separator, and a portion of the first weir may form a lug extending a certain distance above the top of the unit separator.

[0027] In one implementation, the top of the unit separator may be substantially horizontal with the inverted arches of the inlet and outlet.

[0028] In one embodiment, two generally parallel plates may extend from both sides of a lug in the first weir to a gap in the second weir. The top edges of these plates may extend to the top of the second weir, and these plates define an overflow path from the lug of the first weir to the gap of the second weir. Attached Figure Description

[0029] To gain a more complete understanding of this disclosure and its purposes and advantages, the following description is given in conjunction with the accompanying drawings, in which:

[0030] Figure 1A first isometric view of a water treatment apparatus including a crossflow settling device according to an embodiment is depicted.

[0031] Figure 2 A second isometric view of a water treatment apparatus including a crossflow settling device according to an embodiment is depicted.

[0032] Figure 3 Depicting Figure 1 and Figure 2 Side view of a water treatment device;

[0033] Figure 4 Depicting Figure 1 and Figure 2 Side view of a water treatment device;

[0034] Figure 5 An isometric view of a crossflow settling device according to an embodiment is depicted;

[0035] Figure 6 A method for treating water using a water treatment apparatus including a crossflow settling device according to an embodiment is described.

[0036] Figure 7 A method for bypassing a crossflow settling device, disclosed according to one embodiment, is described. Detailed Implementation

[0037] The implementation relates to a crossflow sedimentation device and its usage. The implementation can induce a crossflow pattern of rainwater to remove sediment and utilize a small sediment fall distance as the sediment is desuspended. For example, the sediment only needs to fall onto the surface of the plate.

[0038] Figures 1 to 5 A view of a treatment apparatus including a crossflow sedimentation device according to an embodiment is shown. The treatment apparatus 100 may include a housing 105. The housing 105 may include an inlet 110 for receiving, for example, rainwater with suspended sediment, and an outlet 115 for discharging rainwater. Water received from the inlet 110 may flow into an inlet chamber 170, into a treatment chamber and sediment storage area 120, into an outlet chamber 175, and out of the treatment apparatus 100 through the outlet 115.

[0039] The processing chamber and sediment storage area 120 may be defined by a front baffle 130, a rear baffle 125 and a short-circuit protection plate 165.

[0040] The housing 105 may include a crossflow settling device comprising multiple pairs of ramps 135 positioned between a front baffle 130 and a rear baffle 125. In one embodiment, two pairs of ramps 135 may be provided, one pair on each side of the centerline of the housing 105. The pairs of ramps 135 may be configured at complementary angles, such as 45 / 135 degrees and 65 / 115 degrees, and a space may be left between the tops of the pairs of ramps 135. The pairs of ramps 135 may be suspended between an inlet weir 140 and an outlet weir 145. A bypass channel wall 155 may be provided, which, together with the inlet weir 140 and the outlet weir 145, provides an area for retaining floatable material (e.g., sediment or other material floating on the water surface). The outlet weir 145 may be provided with a notch 150 that allows some water to flow into and out of the inlet chamber 175.

[0041] The tops of the inlet weir 140 and the notch 150 can be at the same height, allowing normal flow bypass. The top of the outlet weir 145 can be at a higher height, allowing bypass under high flow conditions. Some floating debris can flow to one side, while others can escape.

[0042] When the flow rate is high, floating debris will flow with the water through the gap 150, enter the outlet chamber 175, and flow out of the treatment device 100 through the outlet 115.

[0043] Water carrying sediment enters a pair of treatment channel openings 190 on the front baffle 130, which, together with a pair of inclined plates 135 and a treatment channel outlet 160 on the rear baffle, form treatment channels. Water in the treatment channels can flow in a cross-flow pattern between each pair of inclined plates 135, causing suspended sediment to settle through sediment outlet 180 to the bottom of the treatment chamber and into the sediment storage area 120. Water containing some sediment that has settled from the suspension can flow into the outlet chamber 175 through the treatment channel outlet 160.

[0044] The housing 105 may further include a diverter 185, which may be provided by the front baffle 130. In one embodiment, the diverter may be attached or otherwise fixed to the front baffle 130. The diverter 185 allows water flow from the inlet 110 to be directed to both sides of the front baffle 130 and into the treatment channel opening 190. The diverter 185 may also assist in capturing floatable debris, as floatable debris may be directed to both sides of the bypass channel wall and trapped.

[0045] refer to Figure 6 According to one embodiment, a method for removing suspended sediments from rainwater is disclosed.

[0046] In step 605, rainwater carrying suspended sediments flows into the inlet chamber of the rainwater treatment device, where it expands to reduce the fluid velocity.

[0047] In step 610, at normal flow rates (e.g., within design limits), water in the inlet chamber may flow into one or more treatment chamber openings and into a treatment channel defined by the treatment channel outlets in the front baffle, a pair of parallel plates, and the rear baffle.

[0048] In step 615, water flows in a cross-flow pattern in the treatment channel, and suspended sediment settles from its suspended state to the bottom of the treatment chamber and the sediment storage area. The sediment can fall out of the treatment channel through side openings between pairs of inclined plates.

[0049] In step 620, the treated water can flow out of the treatment channel and enter the outlet chamber through the treatment channel opening on the rear baffle.

[0050] In step 725, the treated water can flow out of the outlet chamber and the housing through an outlet (such as a pipe).

[0051] refer to Figure 7 According to an embodiment, a method for bypassing a crossflow settling device is disclosed. For example, at high flow rates, the bypass channel and the floatable material retention zone can function, and the floatable material can be retained in the bypass floatable material retention zone. However, at very high flow rates, the entire outlet weir can be submerged, and all floatable material can be washed out of the floatable material retention zone.

[0052] In step 705, water can enter the shell through the inlet and flow into the inlet chamber.

[0053] In step 710, when the flow velocity exceeds the design limit, water flows through the inlet weir and enters the bypass channel and two floatable debris retention zones. The bypass channel is defined by the inlet weir, the bypass channel wall, and the outlet weir. The floatable debris retention zones are defined by the inlet weir, the outer side of the bypass channel wall, the shell wall, and the outlet weir.

[0054] In step 715, at high flow rates, water can flow through the bypass channel. Any floatable material accompanying the water can be retained in the floatable material retention area. Some water can flow out from the gap in the outlet weir and into the outlet chamber.

[0055] In step 720, water can flow through the outlet weir at the end of the bypass channel and exit into the outlet chamber. At high flow rates, floating debris in the bypass channel can be carried by the water flow over the gap and into the outlet chamber.

[0056] In step 725, water can flow out of the outlet chamber and the shell through the outlet.

[0057] It will be understood by those skilled in the art that this invention is not limited to the specific details shown and described above. Rather, the scope of this invention includes combinations and sub-combinations of the above features, as well as variations and modifications not found in the prior art. It should be further understood that these embodiments are not mutually exclusive.

[0058] It will be readily understood by those skilled in the art that the embodiments disclosed herein have broad applicability and application. Many embodiments and modifications, as well as numerous variations, modifications, and equivalent arrangements, other than those described herein, will be apparent or reasonably expected from the invention and its foregoing description without departing from the spirit or scope of the invention.

[0059] Therefore, although the present invention has been described in detail herein in conjunction with its exemplary embodiments, it should be understood that this disclosure is merely illustrative and exemplary, and is intended to provide a full disclosure of the invention. Consequently, the foregoing disclosure is not intended to interpret or limit the invention or otherwise exclude any other such embodiments, adaptations, variations, modifications, or equivalent arrangements.

Claims

1. A rainwater treatment device, comprising: The shell has a base plate and walls; An inlet, formed in the wall, receives rainwater, including suspended sediment, into an inlet chamber of the housing, the inlet chamber being defined by a first portion of the wall and a front baffle extending vertically from the bottom plate of the housing; An outlet, formed in the wall, discharges rainwater from the outlet chamber of the housing, the outlet chamber being defined by a rear baffle, a second portion of the wall, and a short-circuit protection plate; A processing chamber and sediment storage area, defined by the front baffle, a third portion of the wall, the rear baffle, and the anti-short-circuit plate, wherein a crossflow settling device is disposed, the crossflow settling device having a processing channel defined by the front baffle, the rear baffle, and a first pair of inclined plates placed on a first side of the centerline of the housing and a second pair of inclined plates placed on a second side of the centerline, the first pair of inclined plates and the second pair of inclined plates being arranged at complementary angles, the first pair of inclined plates and the second pair of inclined plates being placed between the front baffle and the rear baffle, the front baffle having a processing channel opening, and the rear baffle having a processing channel outlet; and A bypass channel includes an inlet weir, an outlet weir, and a pair of bypass channel walls, wherein the height of the top of the inlet weir is the same as the height of the outlet weir between the bypass channel walls, but lower than the height of the top of the outlet weir outside the bypass channel and the height of the bypass channel walls, wherein when the flow exceeds a limit, the bypass channel receives the flow flowing over the inlet weir, thereby bypassing the treatment chamber and sediment storage area. In this process, under normal flow conditions, rainwater flows into the inlet and enters the inlet chamber, enters the treatment channel through the treatment channel opening, and enters the outlet chamber through the treatment channel outlet. The rainwater flows in a crossflow pattern, causing sediments to fall from the suspension and flow out of the crossflow settling device through the openings at the bottom of the paired inclined plates.

2. The rainwater treatment device according to claim 1, wherein at a high flow rate, rainwater flows through the inlet weir and either enters the bypass channel and flows through the gap of the outlet weir and into the outlet chamber, and flows out of the housing through the outlet, or enters the floatable material retention area between the bypass channel wall and a third portion of the wall.

3. The rainwater treatment device according to claim 2, wherein at very high flow rates, floating matter overflows the outlet weir and the walls of the pair of bypass channels and enters the outlet chamber.

4. The rainwater treatment apparatus according to claim 1, wherein the complementary angle is configured such that the first pair of inclined plates and the second pair of inclined plates are respectively positioned at angles of about 45 to 65 degrees and about 135 to 115 degrees relative to the horizontal line.

5. The rainwater treatment device according to claim 1, wherein the width of each individual inclined plate of the first pair of inclined plates or the second pair of inclined plates is less than the length of the individual inclined plate.

6. The rainwater treatment apparatus of claim 1, wherein the spacing between the first pair of ramps or the second pair of ramps is between 1 and 4 inches.

7. The rainwater treatment device according to claim 1, further comprising: Diverter, wherein the diverter is located in the inlet chamber and directs rainwater into the treatment channel.

8. A method for removing suspended sediments from rainwater, comprising: The rainwater treatment device receives rainwater containing suspended sediment at an inlet in the wall of the rainwater treatment device, the rainwater treatment device having a housing with a bottom plate and walls, wherein the rainwater flows into an inlet chamber defined by a first portion of the walls and a front baffle extending vertically from the bottom plate of the housing; The rainwater, including suspended sediments, is received in a treatment chamber defined by a front baffle, a second portion of the wall, a rear baffle, and a bypass baffle, and the treatment chamber is equipped with a crossflow settling device. The crossflow settling device with a treatment channel receives rainwater containing suspended sediment. The treatment channel is defined by the front baffle, the rear baffle, a first pair of inclined plates placed on a first side of the centerline of the housing, and a second pair of inclined plates placed on a second side of the centerline. The first pair of inclined plates and the second pair of inclined plates are arranged at complementary angles and are positioned between the front baffle and the rear baffle. The front baffle has a treatment channel opening, and the rear baffle has a treatment channel outlet. The rainwater is allowed to flow in a cross-flow pattern through the cross-flow settling device at a normal flow rate, causing suspended sediments to fall from the suspension and flow out of the cross-flow settling device through the openings at the bottom of the paired inclined plates. Rainwater with some suspended sediment removed is received in the outlet chamber defined by the rear baffle, the second part of the wall, and the short-circuit protection plate; At high flow rates, rainwater carrying suspended sediments is received into a bypass channel, which includes an inlet weir, an outlet weir, and a pair of bypass channel walls. The top of the inlet weir is at the same height as the top of the gap in the outlet weir and is lower than the top of the outlet weir and the top of the bypass channel walls. When the flow rate exceeds a limit, the bypass channel receives the flow flowing through the inlet weir, thereby bypassing the treatment chamber and the sediment storage area. The rainwater carrying suspended sediments flows through the inlet weir and into the bypass channel, and flows through the gap in the outlet weir and into the outlet chamber. and The rainwater, from which the suspended sediment has been removed, is discharged through an outlet in the third section of the wall.

9. The method of claim 8, wherein at high flow rates, some rainwater flows over the inlet weir and enters the floatable material retention zone between the bypass channel wall and a third portion of the wall.

10. The method of claim 9, wherein the floatable object is held in the floatable object holding area.

11. The method of claim 10, wherein at very high flow rates, the floatable material overflows the gap in the outlet weir and the walls of the pair of bypass channels, and enters the outlet chamber.

12. The method of claim 9, wherein the complementary angle is configured such that the first pair of ramps and the second pair of ramps are positioned at angles of approximately 45 to 65 degrees and approximately 135 to 115 degrees relative to the horizontal line, respectively.

13. The method of claim 9, wherein the width of each individual inclined plate of the first pair of inclined plates or the second pair of inclined plates is less than the length of the individual inclined plate.

14. The method of claim 9, wherein the spacing between the first pair of ramps or the second pair of ramps is between about 1 inch and 4 inches.

15. The method of claim 8, wherein the rainwater is introduced into the treatment channel via a diverter.

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