This application claims priority to the Dutch application number 1037598 which was filed Dec. 30, 2009, which is hereby incorporated by reference in its entirety.
The invention is in regards to a structure for the sorting of waste paper, comprising a slanted conveyor belt with drive mechanisms, load mechanisms to deposit raw material mixture at the low end of the conveyor belt, and air pressure equipment placed nearer the upper end of the conveyor belt.
Arrangements of this type are known. They are used to separate waste paper into different components which can be marketed separately. The price that may be obtained for these separate paper components is influenced by its homogeneity, quality, and absence of non-paper components. This because the buyer, usually a paper trader, distributor, manufacturer, converter, requires a constant quality. For this the buyer needs to know as accurately as possible the quality and properties of the offered wastepaper. In presently used constructions, waste paper is placed and transported upwards on a conveyor belt. The waste paper is then dropped from the end of the conveyor belt. Air pressure equipment separates the falling paper, whereby the more compact components will spread less then loose leafs and light folders. The speed of the conveyor belt is regulated to avoid the paper on the belt from becoming airborne, and this is usually at around 2 meters per second.
The problem with these presently used constructions-is-that-they hardly separate from one another the folders, newspaper and magazines that comprise the waste paper. Folders, newspapers and magazines all remain as compact components, and are hardly separated by the air flow. This is especially the case with folded newspapers, which have many of the characteristics of magazines.
The apparatus of the invention is specifically intended to create and sort a mixture of loose sheets, folders, newspapers and magazines, with at least one distinguishing feature that the motors of the conveyor belt are adjusted to operate at a speed of at least 3 meters per second. Consequently the higher transport speed results in loose sheets quickly becoming airborne, and the folders, newspapers and magazines start to tumble when they hit the conveyor belt, increasing the chance that they partially open up, and consequently obtain a larger surface area. For a magazine the surface area in relation to the weight is limited. Therefore, the air pressure will have more influence on the airborne folder and newspaper materials, which consequently will be blown a longer distance.
Another aspect of the invention is that the conveyor belt is outfitted with cross bars to cause the falling folders, newspapers and magazines to tumble, thus further increasing the open surface area of the materials. Due to the high speed of the belt, folders and/or newspapers have the tendency to lay dormant, which is alleviated by the cross bars. With the passing over every bar the folders and/or newspapers receive an additional impulse to tumble, again increasing the unfolding of these materials. Heavier magazines will not be effected and remain flat on the conveyor belt, further aiding the separation.
The invention also has as characteristic that the construction is fitted with additional air pressure and/or air vacuums fitted to at least one side of the conveyor belt, placed above the surface of the conveyor belt and positioned to blow over/above the surface of the conveyor belt.
to the air pressure and/or vacuum devices separate the loose sheets, folders and newspapers that have become airborne from the conveyor belt and/or those paper products that opened sufficiently to be separated in this phase of the process.
The invention also includes the characteristic that the air pressure is placed below the upper end of the conveyor belt, in the form of a fan with a large surface area, as well as an air knife. The fan performs the actual separation, while the air knife causes the loose leaf pages, folders, newspapers or magazines that have come free of the conveyor belt to again tumble, therefore further opening these materials and increasing the probability that they will be dispersed by the fan. By preference, the air knife will be placed lower than the end of the conveyor belt. This is to prevent the airborne sheets from gathering at the air knife and causing a blockage.
Another aspect of the invention is that the air knife has a. stopcock (airflow shutter) and control mechanism to regulate pulsing airflow. By causing a pulsating airflow, only a part of each sheet, folder, newspaper or magazine is struck by the airstream. This causes the folder, newspaper or magazine to tumble wilder.
The invention therefore has a characteristic that the stopcock (shutter) may be opened at arbitrary moments, for short periods of time, to permit intermittent airflow to the air knife.
The invention can include detection equipment placed at the upper end to signal to the air knife that material is approaching on the conveyor belt. Thus, the air knife is activated only when a loose sheet, folder, newspaper or magazine approaches the upper end of the conveyor belt.
The detection equipment can suffice with a simple light source and receptor (motion detector). Eventually, the detection equipment can also be triggered by optical recognition in the form of paper brightness and/or reflection (gloss).
The invention entails a reduction in the amount of air passing through the air knife and optimizes the tumbling of the folder, newspaper or magazine by connecting the detectors to the air knife. The detectors activate the swift opening and dosing (pulse or burst) of the air knife when the upper or lower end of an object leaves the conveyor belt. As a result the object is struck by air from the air knife in a defined area.
The invention entails an air knife that consists of a series of nozzles in row, connected to detectors in row, each with a stopcock (airflow switch or regulator) which activates the airburst when the aligned detector detects the upper or lower end of an object.
The invention is also related to the method of sorting waste paper, through the use of equipment as outlined herein.
The invention is further described in connection with the following sketches (drawings), where:
Instead of a fan 8, it is also possible to rely upon a vacuum system to collect the folders, newspapers and loose sheets from the conveyor belt 1. Also, a combination could be installed, in which a fan 8 blows the folders and newspapers from one side of the conveyor belt 1 into a vacuum collector placed on the opposite side of conveyor belt 1. Folders and newspapers that are not blown and collected remain on the conveyor belt 1 to fall off of the end, where mainly magazines fall into container (bin) 5 and folders and newspapers mainly fall into container (bin) 6.
Number | Date | Country | Kind |
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1037598 | Dec 2009 | NL | national |