WO2007034245A1

WO2007034245A1 - Method and mechanism for cleaning beach sand

Info

Publication number: WO2007034245A1
Application number: PCT/GR2006/000047
Authority: WO
Inventors: Andreas Rentzos; Paraskevi Rentzou
Original assignee: Ram Europe
Priority date: 2005-09-21
Filing date: 2006-09-15
Publication date: 2007-03-29
Also published as: GR1005509B; GR20050100484A; EP1926860A1; CN101268233A

Abstract

A method having two separate work phases , where, during the first one, the sand destined to be cleaned is stirred up by a rotor (2) , which rotates at a steady rotation speed, whilst the mechanism passes over the surface of sand to be cleaned. During stirring up the waste encountered in the whole working depth are ejected onto a conveyor belt (5) together with a small quantity of stirred sand and then directed to screens where the sand is separated and the remaining waste is ejected into a waste bucket. During the second work phase, the major proportion of the stirred sand, which is now clean, is moved in a flow (12) between the sphenoid blade (1) and the conveyor belt, without any waste, and distributed on the ground. An advantage of this invention is the economy of energy consumption and the improvement of beach sand cleaning machinery performance.

Description

METHOD AND MECHANISM FOR CLEANING BEACH SAND

This invention relates to trailers or automotive vehicles fitted with a special mechanism which, on the basis of a particular method, is used in the cleaning of sand on beaches from various types of waste.

The sand beach waste cleaning mechanisms, are internationally known to be fitted with a rotary cylinder (rotor) which operates in a manner which ejects and propels the sand together with the waste onto a rolling conveyor belt so that after screening the waste collected will be discharged in the usual manner into waste buckets.

Mechanisms which, with the assistance of a sphenoid blade, excavate the sand with the waste and drive it towards a conveyor belt so that again, after screening, the waste is removed, are also internationally known. Such mechanisms and/or combinations of such mechanisms with the previous mechanisms fitted with rotor are mentioned in Patents, e.g. US 2002170765, JP 2004324399, US 6094847, JP 4174114 and 0 486 053 Bl.

All the known mechanisms for cleaning sand beach such as those mentioned here, convey and screen all the quantity of cleaned sand, a factor which requires large surfaces of screens or conveyor belts/screens and absorbs great amounts of energy per cubic meter of cleaned sand. Further, in normal usage, are required very strong and increased power tractors.

The advantage of this invention is that the method of sand - waste separation is carried out in two particular phases. During the first work phase, by means of the rotor (2) rotating in the direction of the arrow (16), while the mechanism moves in the direction of the arrow (15), all the waste together with a minimum amount of sand is guided to a moving, vibrating conveyor belt/screen (5) following which the waste is deposited into a waste bucket, whilst during the second work phase, the larger quantity of sand, now cleaned, bypasses the sphenoid blade (1) and is deposited on the ground without the need of screening since it is already clean. This method of waste separation through the two work phases of the invention is achieved with a special mechanism which is also the particular advantage of this invention.

With this method of sand cleaning and its mechanism of application the invention achieves, apart from an excellent quality of cleaning, much greater productivity in comparison to other well-known mechanisms having the same power and energy consumption.

According to this invention's method of beach sand cleaning from waste and, during the first work phase, stirring of the sand takes place at a working depth (H) Fig. 1, so that the waste will be collected over the whole working depth and from the surface and then ejected towards the moving conveyor belt (5) in a manner which ensures it will not return to the ground surface behind the stirring mechanism (2).

During this first work phase all the waste, irrespective of size, is collected due to the fact that the stirring up mechanism is situated at a fixed distance of just 4mm approximately from the horizontal sphenoid blade (1), namely at such a small distance so that even the small cigarette butts are also collected from the sand to be cleaned. Furthermore, a small amount of the stirred sand is ejected together with the waste towards the conveyor belt (5). But due to the fact that the sand has much smaller size and greater mass in comparison to the collected waste, a much smaller quantity of sand is ejected towards the conveyor belt, follows the passage of the waste and then falls down from the screen or the conveyor belt/screen to the ground. During the second work phase of sand cleaning, according to this invention, the remaining quantity of sand which is significantly greater, located in front of the sphenoid blade (1), and, whilst this blade moves forward, the sand passes over the blade through the fixed gap/window created by the distance between the blade and the edge of the conveyor belt (5), and falls down on the ground without guiding it towards the screen since it is already cleaned sand.

The described method for cleaning beach sand in this invention is superior from the point of view of energy consumption to the well known methods of stirring up, loading and screening all the quantity of sand designated by the working depth because according to the invention there is no requirement to load and screen the greater proportion of the processed sand.

Another additional advantage of the method of sand cleaning utilized in this invention is the reduced requirement for screening surface or conveyor belt /screen because a very small section of the sand now requires separation from the waste through screening, since the greater quantity of waste has already been collected during the first work phase, e.g. throughout the stages of stirring and ejection.

Important elements of the special mechanism are: a). The rotor (2) which is made up of a metal cylinder (14), fitted out with metal spikes (3) the edges of which terminate to a cylindrical surface of a suitable diameter so as to meet the demands of working depth (H). The spikes are fixed equidistantly along a line parallel to the cylinder's axis either in a helicoid line. Figure 1 shows the rotor (2) of the invention's mechanism for the stirring up the sand with, preferably, 5 (five) series of spikes. The length of the spikes should preferably be approximately 60% of the radius of the cylindrical surface. The edge of each spike during its rotation passes over the cylindrical surface with an axis equal to the rotors width. The number of spikes, the distance between the spikes in a series and the location of the spike series are allocated so that a gap of approximately lmm is left between the trace of the spikes on the ground, all over the working width. This constructional configuration allows the collection of even smaller pieces of waste. The rotor rotates at a steady speed around the axle (6) in the direction of the arrow (16), whilst the mechanism, fitted to an automotive vehicle or trailer, moves in the direction of the arrow (15). The axle (6) is firmly supported on the sheer supports of the casing (13) which, at the same time, constitutes the frame of the mechanism. b). The sphenoid blade (1) (also referred to as a "knife" or "blade"), together with the rotor (2) designate the working depth. It has, according to this invention, a cylindrical form on its upper surface, so as to have a stable distance from the cylindrical surface designated by the edge of the spikes (2) of approximately 4mm so as to be able to collect even smaller pieces of waste, such as, e.g. cigarette butts. The sphenoid blade extends to the front surface in an acute peak whilst, for reasons of resistance, the rear surface of its cross-section is wider. It is constructed of reinforced steel or other similar material of high resistance to abrasion or bending and, according to requirements, it may also be perforated. It covers approximately 45° of the circumference of the rotor and is supported, with the possibility of easy replacement via the screws, as does the rotor axle on the sheer supports to the right and the left of the casing (13), which at the same time, is the frame of the mechanism. c). The rotation/suspension axle of the casing/frame (13) of the mechanism is fitted in the same position as the terminating and directional change axle on the frame (9) of the conveyor belt (5), so that the casing (13) has the ability to rotate with the assistance of the hydraulic cylinders (8) to adjust the working depth (H) and the angle of the sphenoid blade (1) down towards the ground. d). The upper surface of the casing (7), the lower section of which collides with and then ricochets a section of the sand and a section of the waste which is ejected from the spikes of the rotating rotor throughout the operation and of course, during the first working phase, as described in the invention. For reasons of accurate working and distribution of the ejected material to the conveyor belt (5), the surface (7) is configured cylindrically with a relatively large radius. It is metallic as is the whole casing. Fig. 1 shows the place in lineal where the waste are ejected (they are marked with squares or circles), as well as those that are ejected from the internal surface (7) of the casing. e). The conveyor belt (5) is fashioned in the form of a mesh grid or as a standard conveyor belt, or as a screen/shaking belt and as a belt with in-between hooks which increases the possibility of transporting waste at a sufficiently greater height, and with lateral supports which ensure the protection of the belt against any wear and tear. The conveyor belt moves and vibrates within the framework (9) via direct and concentric rubber rollers. The lower section is supported on bases of plastic wheel supports which are housed on the sides of the frame (9). The frame (9) has a high inclination at its beginning and a lower one on its end which is followed by the belt in such a manner that the collection of waste and its transfer will be more accurate. The transfer in the higher inclination is supplemented by hooks fitted to the belt.

To the important elements of the special mechanism described from a) to e), its constructional configuration and the way in which participate to the operation of the invention, there is the need to include the requirement of a dimensioning of the gap/window between the conveyor belt (5) and the sphenoid blade (1), because this is a significant parameter for good working operation during the second work phase, as anticipated in the invention. Thus, was ascertained experimentally, a good and unobstructed flow of the sand (12) which was not transferred by the conveyor belt when the breadth of this opening/window is constructed equal to 25% approximately of the radius of the rotor (2). The gap's width covers all the operating width, of the rotor (2). as well as of the belt (5). Logically, there are other factors too which influence the quality of the operations according to the invention, such as the rotating speed of the rotor (2), the moving speed of the mechanism, the working depth and the working angle and other factors, and all these factors are taken into consideration and are being improved.

As depicted in Fig. 2 and from the foregoing, the frame (9), of the conveyor belt (5), together with the distribution mechanism, all housed together in the casing (13), which is hinged to the axle (4), there is a possibility for these to be fitted to a frame (11), as described as an example for an automotive, four-wheeled, 4x4 vehicle and adjusted via hydraulic cylinders (10), so that another possibility of adjusting the working depth is created through the distance (Hl) The frame (11) can be a section of the frame of a trailer vehicle or an automotive vehicle. According to requirements it could be a wheeled vehicle (4x4, 6x6, 8x8) moving on all wheels or a crawled vehicle even fitted with a waste collection and transfer container.

Claims

CLAIMS:

1. Method of cleaning sand from waste on beaches with distribution to a conveyor belt and screening with a screen or conveyor belt/screen CHARACTERIZED in that the waste is removed together with a minimum amount of sand in relation to the total quantity of unclean sand and are conveyed in a first phase to a waste bucket thought a conveyor belt (5) and screen , whilst in a second phase the remaining significant but now clean quantity of sand (12) is deposited back on its place.

2. Mechanism sending the beach sand for cleaning in accordance with claim 1, placed in a automotive vehicle or trailer vehicle and with a conveyor belt (5),with a rotating rotor (2) with metal spikes (3) based on it ,of the same length and along its radius, also fitted out with a sphenoid blade (1) for sectioning up of a particular thickness of sand during its passage over the surface of the beach. CHARACTERIZED by fact that the sphenoid blade (1) has its surface towards the rotor (2) cylindrical and at a stable distance of approximately 4mm from the edges of the metal spikes (3) of the rotor, and by the fact that the suspension of the mechanism coincides with the axle (4) for changing the direction of the conveyor belt (5) and located at a stable distance from the rotation axle of the rotor (6), as well as of the sphenoid blade (1) in a manner which enables the mechanism to rotate in order to change the angle of the ground cutter, without changing the distance between the edges of the metal spikes (3) from the sphenoid blade (1) and from the conveyor belt (5) as well as without changing the gap between the sphenoid blade and the conveyor belt.

3. Mechanism for sending beach sand to be cleaned from waste in accordance with claims 1 and 2, CHARACTERIZED by an upper casing (7) for the ejection of waste and sand to the conveyor belt in the shape approximate of a cylindrical surface and hydraulic cylinders (8) for changing the angle of the ground cutter.

4. Conveyor belt/screen for sending beach sand for cleaning from waste in accordance with claims 1, 2 and 3, CHARACTERIZED by a frame (9) suspended on the frame of an automotive vehicle or trailer vehicle (11) via a hydraulic cylinder (10) to adjust each time the distance of the common suspension (4), of the conveyor belt with the sending sand to be cleaned mechanism, from the ground.

5. Conveyor belt/screen in accordance with one of the claims of 1, 2, 3 and 4 CHARACTERIZED by a double inclination, which is greater close to the ground but with a short length and smaller inclination and longer length accordingly.

6. Mechanism for sending sand for cleaning from waste, in accordance with claims 1, 2, 3, 4, CHARACTERIZED by the fact that a fixed distance of the casing suspension axle (13) of the mechanism from the suspension axle (6) of the rotor (2), is selected so that the gap between the sphenoid blade (1), firmly affixed to the casing (13) and the conveyor belt (5) for the flow of cleaned sand (12), to have an opening equal to approximately 25% of the radius of the rotor

(2).

7. Rotor (2) of the mechanism for sending beach sand for cleaning from waste, consisting of metal spikes (3) and a metal cylinder (14), the horizontal rotating axle (6) of which is firmly assembled on the casing (13) of the mechanism, in accordance with claims 1, 2, 3, CHARACTERIZED by the fact that the spikes (3) are positioned so that their edges terminate in a concentric with the metal cylinder, cylindrical surface (14), having a length of approximately 60% of the radius of the cylindrical surface, preferably arranged in equidistant series along in straight or helicoids lines over the whole surface of the metal cylinder (14).

8. Sphenoid blade (1) of mechanism for sending beach sand for cleaning from waste, in a fixed position related to the casing (13) of the mechanism, the upper surface of which is cylindrical with a radius of 4mm greater than the radius of the rotor (2), in accordance with claims of I₅ 2, 6, CHARACTERIZED by the fact that it is constructed from reinforced steel, firmly supported on the casing (13) through screws , so that it is possible to be replaced and, according to requirement, may also be perforated or in the form of a grid and also by the fact that the circular arc of the rotor to which it corresponds, is approximately 45°.