WO2016049112A1

WO2016049112A1 - Brushless perforated panel screen

Info

Publication number: WO2016049112A1
Application number: PCT/US2015/051597
Authority: WO
Inventors: Rob Sabol; Kenny OYLER; Barry Weber
Original assignee: Jwc Environment, Llc
Priority date: 2014-09-24
Filing date: 2015-09-23
Publication date: 2016-03-31

Abstract

Provided is a screening apparatus for removing solids from a wastewater stream. The apparatus includes a plurality of perforated panels connected in series to form an endless belt of panels, the perforated panels having an inside surface and an outside surface. Also included is a pair of rotatable support members to support the endless belt of panels, and a drive for moving the endless belt of panels through a liquid having entrained solids. A spray system disposed within the endless belt and configured to spray a liquid toward the inside surface, and the perforations in the panel have a diameter than is larger than a thickness of the panel between the inside surface and the outside surface.

Description

BRUSHLESS PERFORATED PANEL SCREEN

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[01] This application claims the benefit of U.S. Provisional Patent

Application No. 62/054,656 filed on September 24, 2014 in the U.S. Patent Trademark Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

[02] Perforated plate screens have been used for years as a means to extract solids from waste streams. The perforated panels, which can be constructed from steel, stainless steel or plastic, have round holes that allow the water pass through while capturing solids too large to pass. The perforated panel screens are used where solids removal of finer particles beyond what a screen employing vertical bars (climber bar screen or chain and rake screen) can remove for the downstream equipment or process.

2. Description of the Related Art

[03] Traditionally the removal of solids from the perforated panels is done by conveying the panels 20, which are attached to a roller chain and driven by an electric motor 40 , i.e., a belt comprised of two continuous lengths of roller chain and perforated panel segments 20. The perforations on the panels are commonly ¼" (6mm), or smaller, allowing classification as a "fine" screen technology. To clear solids from the panels 20, a spray bar 50 and a mechanically rotating brush 10 are incorporated near the top of the fine screen apparatus. In the conventional screens, using a brush was required to effectively clean solids from the panels. These elements are in contact with the perforated panels, removing the solids into a discharge opening 90 guided by a deflector plate 30 as shown in FIG. 1. The brush 10, which is rotating above 100 RPM, removes material from the screen panel 20 and flings it in uncontrolled directions. Some of the material will bypass the deflector plate 30 interface and re-enter the waste stream downstream of the screen 100. This material is typically classified as carry-over in the industry and decreases the screen's capture performance as the material is now beyond the screen's ability to remove.

[04] There are three key elements that make the brush an undesirable feature of the Fine Screen: (1) Uncontrolled flinging of screenings within the discharge compartment of the machine, leading to material bypass; (2) The rotating brush is a significant maintenance item that requires periodic adjustment to maintain contact with the screen panels. If contact is not maintained, the screen may fowl with solids and create a decrease in performance and possible failure. Maintenance of the brush is also a potential health risk as workers are exposed to the fecal matter and possible sharps (razors and syringes) that can be caught in the bristles of the brush; and (3) The brush is also a wear item that will require replacement during the life of the screen. If maintenance is not periodically performed on the brush, the life of the brush will be decreased and replacement required. Additionally, the brush requires operational cost to operate the motor. SUMMARY OF THE INVENTION

[05] According to an aspect of the present invention, there is provided a screening apparatus for removing solids from a wastewater stream. The apparatus includes a plurality of perforated panels connected in series to form an endless belt of panels, the perforated panels having an inside surface and an outside surface. Also included is a pair of rotatable support members to support the endless belt of panels, and a drive for moving the endless belt of panels through a liquid having entrained solids. A spray system disposed within the endless belt and configured to spray a liquid toward the inside surface, and the perforations in the panel have a diameter than is larger than a thickness of the panel between the inside surface and the outside surface.

[06] According to another aspect, the perforations in the panel have a diameter than is larger than 1.5 times the thickness of the panel.

[07] According to another aspect, the apparatus includes a deflector plate and a discharge opening for receiving solid material from the outside surface of the endless belt of panels, and the spray system is configured to impact the inner surface of the endless belt above the discharge opening.

BRIEF DESCRIPTION OF THE DRAWINGS

[08] The above and other features and aspects of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[09] FIG. 1 is an illustration of a conventional perforated panel screen; [10] FIG. 2 is a perforated panel in accord with an embodiment of the present application;

[1 1] FIG. 3 is an illustration of a perforated panel screen in accord with an embodiment of the present application.

DETAILED DESCRIPTION OF THE INVENTION

[12] The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

[13] It is an aspect of the present application to provide an improved panel having cleaning characteristics that do not require a brush for cleaning. As shown in FIG. 2, a panel 20 in accord with a first embodiment has a panel thickness 60 that is greater than the diameter of the holes 70 in the panel 20. By constructing the perforations (holes) in this manner, the perforated panel is more susceptible to cleaning by use of a spray on the back side of the panel 20. Accordingly, the perforated panel can be adequately cleaned by use of a spray without using a brush on the front side of the panel. In a preferred embodiment, the panel thickness is 1 ½ times the diameter of the perforations.

[14] Additionally, it is another aspect to provide a method and configuration for removing solids from the waste stream. This is accomplished by using perforated panels 20 where the thickness of the panel 60 is greater than the diameter of the holes 70 in the panel (FIG. 2). A spray water system 50 (FIG. 3) sprays water through the panel 20 to remove solids from the panel 20 and direct them into the discharge point 80. The spray water system 50 can be located above the discharge point 80 to improve capture by directing the solids away from the deflector plate 30 and guiding them into the discharge opening 90. The location and spray angle of water, along with the panel thickness and construction, eliminates the need for a mechanical means of removing the solids (e.g. rotating brush).

[15] This removal of the rotating brush creates a simplified product that requires less maintenance and, more importantly, removes eliminates the need for plant personnel to clean the brush, which could put them in contact with hazardous elements such as human feces and sharps.

[16] The panels having the perforations as described above may be flat or curved). The panels of the invention are of a minimum thickness of 1.5X than the diameter of the perforations in the panel. As an example, a ¼" hole would use a minimum 3/8" thick panel.

Claims

WHAT IS CLAIMED IS:

1. A screening apparatus for removing solids from a wastewater stream, comprising:

a plurality of perforated panels connected in series to form an endless belt of panels, the perforated panels having an inside surface and an outside surface;

a pair of rotatable support members to support the endless belt of panels;

a drive for moving the endless belt of panels through a liquid having entrained solids; and

a spray system disposed within the endless belt and configured to spray a liquid toward the inside surface,

wherein the perforations in the panel have a diameter than is larger than a thickness of the panel between the inside surface and the outside surface.

2. The screening apparatus for removing solids from a wastewater stream according to claim 1 , wherein the perforations in the panel have a diameter than is larger than 1.5 times the thickness of the panel.

3. The screening apparatus for removing solids from a wastewater stream according to claim 1 , further comprising a deflector plate and a discharge opening for receiving solid material from the outside surface of the endless belt of panels, and

the spray system is configured to impact the inner surface of the endless belt above the discharge opening.