System for detecting conductive contaminants and method of use

• US 6,469,526 B1
• Filed: 04/12/2000
• Issued: 10/22/2002
• Est. Priority Date: 04/12/2000
• Status: Expired due to Fees

• Current Assignee: Synagro Technologies Incorporated (Carlyle Group LP)
• Original Assignee: Synagro Technologies Incorporated (Carlyle Group LP)
• Inventors: Franklin, Marshall R.
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): KERVEROS, DEMETRIOS C
• Application Number:
  US09/547,555
• Time in Patent Office: 923 Days
• Field of Search: 324/701, 324/71.1, 324/71.4, 324/439, 324/663, 324/698, 738/655, 75/101.9, 210/603, 210/608
• US Class Current: 324/701
• CPC Class Codes: B07C 2501/0036 Sorting out metallic particles
• CPC Class Codes: B07C 2501/0054 Sorting of waste or refuse
• CPC Class Codes: B07C 5/344 according to electric or electromagnetic properties sorting according to size measured electrically or electronically B07C5/08; material testing by magnetic means G01N24/00, G01N27/00, by electrical means G01N27/00; electrical measuring devices in general G01R; coin testing G07D5/00

Abstract

The present invention provides a system to detect conductive contaminants interspersed within unconsolidated materials. By using the system described herein, voluminous amounts of unconsolidated materials such as soils, waste streams, hay, and similar non-conductive materials may be processed such that conductive contaminants, namely metal objects, may be identified and removed from the processed material. In general, the present invention utilizes the conductive property of these contaminants to alert the system such that the contaminant may be removed. By passing the unconsolidated materials across an arrangement of different contacts placed in close proximity, metal or similar conductive contaminants will complete an electrical circuit that signals a sensor within the circuit and initiates a partial shut down procedure. Though this sensor is preferably at least one programmable voltage sensor, the sensor may comprise a current transformer or light incorporated into the electrical circuit that detects each conductive contaminant. A light sensor that may trigger at least one relay to halt the processing of material as described herein may detect this emission. This system and its method of use may be adapted to detect conductive contaminants in voluminous, unconsolidated materials in a variety of applications.

Claims

1. A system for detecting at least one conductive contaminant in unconsolidated materials comprising:

at least one nonconductive section, wherein each section has an exterior surface and an interior surface, wherein a plurality of contacts, identified as first contacts or second contacts, are secured or disposed through the section such that at least 1.5 inches (3.8 cm) of each of the contacts extends above the exterior surface of one of the sections;

an uncompleted electrical circuit comprising;

at least one power source wherein each first contact is electrically connected to one power source; and

at least one sensor wherein each second contact is electrically connected to at least one sensor and wherein at least one sensor is electrically connected to each power source; and

wherein each contaminant in unconsolidated materials may be disposed within ¼

inch (0.64 cm) of one of the first contacts and within ¼

inch (0.64 cm) of one of the second contacts, thereby completing the circuit and activating at least one sensor.

2. The system of claim 1 further comprising a first conveyor capable of forwarding the materials possibly comprising at least one contaminant onto or near one of the first contacts and onto or near one of the second contacts.

3. The system of claim 2 further comprising at least one hopper capable of guiding the materials such that each contaminant falls onto or near one of the first contacts and onto or near one of the second contacts.

4. The system of claim 1 wherein each power source comprises at least one transformer.

5. The system of claim 1 wherein the sensor comprises an emission source that emits an emission detectable by at least one emission detector that signals at least one relay.

6. The system of claim 1 wherein the sensor comprises at least one current transformer.

7. The system of claim 1 wherein each sensor is electrically connected to at least one relay system that will stop each conveyor.

8. The system of claim 1 further comprising:

a shaft rotatably attached to a frame;

at least one support disk wherein each disk has an outer rim fixedly attached to the shaft wherein each section is fixedly attached or secured to the outer rim of each disk; and

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed between and provides the electrical connection between at least some of the first contacts and at least one power source and wherein the second ring is disposed between and provides the electrical connection between at least some of the second contacts and ar least one sensor.

9. The system of claim 1 wherein each first contact is electrically connected to the other first contacts by at least one bus bar disposed on or secured to at least one interior surface of at least one section such that each bar is electrically connected to the first ring via at least one conductive brush.

10. The system of claim 1 further comprising:

a shaft rotatably attached to a frame;

at least two support disks, each having an outer rim fixedly attached to the shaft, wherein a plurality of sections are fixedly attached or secured to the outer rim of each disk to form a detection wheel about the shaft;

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed in between and provides the electrical connection to at least some of the first contacts and at least one power source and the second ring is disposed in between and provides the electrical connection to at least some of the second contacts and at least one sensor; and

at least one bus bar connecting each first contact to the other first contacts disposed on the interior surface of each section such that each bar is electrically connected to the first ring via at least one conductive brush.

11. The system of claim 10 further comprising:

at least one conveyor capable of forwarding the materials to the exterior surface of at least one section;

at least one hopper capable of guiding the materials leaving the conveyor such that the materials are guided onto the exterior surface of at least one section; and

at least one sensor electrically connected to at least one relay system that will stop each conveyor.

12. The system of claim 11 further comprising a second conveyor disposed below the wheel such that the second conveyor may move reviewed materials from the system.

13. The system of claim 10 comprising an air manifold attached to the frame and positioned such that the manifold may force air at the contacts extending from the exterior surface of a section facing the second conveyor such that material or contaminants disposed within the contacts will be dislodged.

14. The system of claim 10 further comprising a wiper disposed about the second conveyer capable of sweeping the materials and contaminants from the second conveyor.

15. The system of claim 10 wherein the system comprises six sections.

16. A system for detecting conductive contaminants in unconsolidated materials comprising:

at least one nonconductive section, having an exterior surface and an interior surface, wherein a plurality of contacts, identified as first or second contacts, are secured or disposed through the section such that at least 1.5 inches (3.8 cm) of each contact extends above the exterior surface;

an uncompleted electrical circuit comprising;

at least one power source electrically connected to the first contacts;

at least one voltage sensor electrically connected to each power source and to the second contacts;

at least one conveyor capable of forwarding the materials to the exterior surface;

at least one hopper capable of guiding the materials leaving the conveyor such that the materials are guided onto the exterior surface;

at least one relay system electrically connected to each sensor that will stop each conveyor;

a shaft rotatably attached to a frame;

at least two support disks, each having an outer rim fixedly attached to the shaft, wherein a plurality of setions are fixedly attached or secured to the outer rim of each disk to form a detection wheel about the shaft; and

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed in between and provides the electrical connection between at least some of the first contacts and at least one power source and the second ring is disposed in between and provides the electrical connection between at least some of the second contacts and at least one sensor;

wherein a conductive contaminant in unconsolidated materials will complete the electrical circuit and activate at least one voltage sensor.

17. The system of claim 16 further comprising a second conveyor disposed below the wheel such that the second conveyor may move reviewed materials from the system;

an air manifold attached to the frame and positioned such that the manifold may force air at the contacts extending from the exterior surface of a section facing the second conveyor such that material or contaminants disposed within the contacts will be dislodged; and

a wiper disposed about the second conveyer capable of sweeping the materials and contaminants from the second conveyor.

18. The system of claim 16 further comprising a rotating spark gap switch that periodically connects each first contact and each power source wherein the switch provides a potential voltage to selected rows of the first contacts such that all first contacts are provided with the potential voltage at cyclical intervals such that the conductive contaminant disposed within the material will complete the electrical circuit while disposed on the detection wheel.

19. The system of claim 18 wherein the switch is rotated by a motor at about 360 rotations per minute such that each first contact receives the potential voltage about 3.6 times per second.

20. The system of claim 16 wherein at least one voltage sensor is electrically connected to an input terminal of at least one transformer.

21. A method of detecting conductive contaminants in unconsolidated materials comprising:

allowing the materials to pour into a hopper that guides the materials onto a rotating detection wheel wherein the wheel comprises;

a plurality of nonconductive sections, having exterior surfaces and interior surfaces, wherein a plurality of contacts, identified as first or second contacts, are secured or disposed through each section such that a distance of no more than ¾

inches (1.9 cm) exists between each first contact and a second contact and at least 1 inch (2.54 cm) of each contact extends above the exterior surface of one of the sections;

an uncompleted electrical circuit comprising;

at least one power source electrically connected to the first contacts;

at least one sensor electrically connected to each power source and

to the second contacts; and

a shaft rotably attached to a frame;

at least two support disks, each having an outer rim fixedly attached to the shaft, wherein each section is fixedly attached or secured to the outer rim of each disk to form the wheel about the shaft;

at least two conductive rings, a first ring and a second ring, fixedly attached to the shaft wherein the first ring is disposed in between and provides the electrical connection between at least some of the first contacts and at least one power source and the second ring is disposed in between and provides the electrical connection between at least some of the second contacts and at least one sensor;

wherein a conductive contaminant in unconsolidated materials will complete the electrical circuit activating at least one sensor;

stopping the first conveyor and a second conveyor disposed below the wheel;

wiping the materials from the second conveyor after a delay sufficient to allow the rotating wheel to dump the materials containing the conductive contaminant onto the second conveyor; and

reactivating both the first and second conveyors to process additional materials.

22. The method of claim 21 further comprising dislodging any materials or conductive contaminants disposed within that fail to drop onto the second conveyor by blowing air at the contacts extending from the exterior surface of a section facing the second conveyor such that material or contaminants disposed within the contacts fall onto the second conveyor.

23. The method of claim 22 further comprising packaging the reviewed unconsolidated material.

24. The method of claim 22 further comprising storing the reviewed unconsolidated material.