Patent Application
20110297591
1. Field of the Invention
The present invention relates generally to the field of equipment for processing recycled materials. More specifically, the present invention discloses a conveyor system for separating mixed recycled materials.
2. Statement of the Problem
Various types of equipment have been used for many years to process mixed recycled materials, such as cans, bottles, paper and corrugated material. Recycled materials are typically collected from consumers and transported to collection centers in a mixed state, with cans, bottles, paper and corrugated material intermixed. These materials must be separated for subsequent processing and sale.
The prior art in this field includes a variety of disc screen devices for classifying recycled materials, as shown for example in U.S. Pat. Nos. 7,004,332 (Davis), 6,648,145 (Davis et al.), 6,250,478 (Davis), 6,076,684 (Bollegraaf) and 7,584,856 (Miller et al.), and U.S. Patent Application Pub, No. 2009/0152173 (Miller et al.). The disc screen has rows of irregular discs (e.g., with a generally square or triangular shape) mounted on a series of rotating shafts. The disc screen is inclined so that lighter flat items such as newspaper and cardboard ride to the top of the disc screen. Heavier recycled items such as bottles and cans are bounced by the rotating irregular discs and tumble to the bottom of the disc screen. The spacing between the discs and shafts allows smaller recycled items to fall through the disc screen.
Disc screen devices of this type have a significant shortcoming in that the rotating shafts and discs are exposed to the recycled materials being processed. Recycled materials often include items such as plastic bags, straps and bottles that can quickly foul the disc screen by becoming stuck between the discs and wrapped around the rotating shafts. This rapidly impairs the functionality of the disc screen and can eventually prevent operation of the system. The disc screen must be periodically shut down to remove such materials, which is time-consuming and can be dangerous.
Solution to the Problem. In contrast to prior art disc screen devices, the present invention employs a conveyor system for separating mixed recycled materials in which an array of beaters strike the underside of an inclined conveyor belt. The recycled materials contact only the upper surface of the conveyor belt, which protects the beaters and drive shafts from fouling. The conveyor carries lighter, two-dimensional recycled materials such as paper and cardboard to its upper end, while heavier, three-dimensional recycled items such as bottles and cans are bounced by the impact of the beaters on the underside of the conveyor belt and fall to the lower end of the conveyor.
Optionally, a blower can be used to blow air against the upper surface of the conveyor belt to help hold lighter, flat recycled items (i.e., paper and cardboard) on the conveyor belt as they are carried to upper end of the conveyor belt. This increases the effectiveness of the present invention in separating paper and cardboard from heavier items, such as cans and bottles.
This invention provides a conveyor system for separating mixed recycled materials containing lighter and heavier recycled materials that employs an inclined conveyor belt with an array of rotating beaters striking the underside of the conveyor belt. A feeder mechanism deposits mixed recycled materials onto the midsection of the conveyor belt. Heavier recycled materials are bounced from the conveyor belt and tumble to the lower end, while lighter recycled materials are carried by motion of the conveyor belt to its upper end.
These and other advantages, features, and objects of the present invention will be more readily understood in view of the following detailed description and the drawings.
The present invention can be more readily understood in conjunction with the accompanying drawings, in which:
a is an exploded perspective view of one of the larger beater assemblies.
Turning to
An array of rotating beaters 40 strike the underside of the conveyor belt 30.
Beaters 40 having arms of different lengths can be employed at different locations under the conveyor belt 30 to provide differing degrees of agitation to the recycled materials. For example, in the embodiment shown in
In operation, mixed recycled materials are deposited onto the midsection of the conveyor belt 30 by the feeder mechanism 15. Recycled materials can either be fed continuously or periodically in separate batches for processing. The impacts of the beaters 40 on the underside of the conveyor belt 30 are transmitted through the conveyor belt 30 to the mixed recycled materials on its upper surface. These impacts cause heavier recycled materials 12 (i.e., primarily cans and bottles) to bounce from the conveyor belt 30 and tumble to the lower end. In contrast, lighter two-dimensional recycled materials 11 (i.e., primarily paper and cardboard) tend to stay on the conveyor belt 30 and are carried by motion of the conveyor belt 30 to its upper end as shown in
Optionally, a fan or blower 50 can be used to direct air against the upper surface of the conveyor belt 30 to hold lighter recycled materials 11 (e.g., paper and corrugated material) against the conveyor belt 30 as these materials are carried by the conveyor belt 30 to its upper end.
It should be understood that this separation process need not be 100% effective to be useful in the recycling industry. Recycled materials can be processed multiple times to achieve any desired quality control requirements for separation of different types of the materials. This can be done by multiple passes through the same equipment, or by a single pass through multi-stage equipment. The present invention can also be combined with other conventional equipment or processes for separating categories of recycled materials. For example, an initial fine screening stage can be used to remove broken glass.
The above disclosure sets forth a number of embodiments of the present invention described in detail with respect to the accompanying drawings. Those skilled in this art will appreciate that various changes, modifications, other structural arrangements, and other embodiments could be practiced under the teachings of the present invention without departing from the scope of this invention as set forth in the following claims.
