Worm composter with a tank featuring a perforated bottom

Abstract

The present invention relates to a worm composter comprising a tank having a perforated bottom (12) and at least one movable scraper bar. Said scraper bar (50 to 53) is driven in translation by its two lateral ends, in a horizontal plane at a predetermined height relative to the perforated bottom (12) of said tank (10), by a scraper bar drive mechanism (50 to 53) disposed outside said tank (10), below or beside the tank (10). Abstract figure: Figure 1

Description

Title of the invention: WORM COMPOSTER COMPRISING A TANK WITH AN OPEN BOTTOM Field of invention

[0001] The present invention relates to the field of vermicomposting (or vermi-composting), in domestic installations, in collective installations for communities for example, or on a larger scale, in industrial installations. Vermicomposting consists of placing earthworms (earthworms) in a tank which feed on organic and plant waste to produce droppings which accumulate and constitute vermicompost with the consistency of potting soil and without odor.

[0002] The aim of vermicomposting is to recover waste into a useful and marketable product by a system fed in layers by cumulative batches of biomass and organic waste. The contents of a tank are inoculated with worms and as the biomass decomposes, other successive layers are added. The compost formed mainly from the droppings of the earthworms is recovered from the perforated bottom of the tank by scraping the surface using a movable blade. State of the art

[0003] Known in the state of the art is the German patent published under number DE4202463, the composter is raised from the ground and has a grid in the lower part through which the granular type components resulting from the composting process pass. So that the grid is not subjected to the weight of all the products contained in the composter, the tank has a conical lower shape and support bars are arranged above this grid. The behavior of a material with a granular structure is characterized by its ability to flow in a manner similar to that of a liquid but this flow is interrupted fairly quickly by a phenomenon of creation of vaults within the material due to the wedging of the grains between them.

[0004] Patent FR2913007 describes another device for extracting granular materials from a tank comprising at its lower part a support grid mounted on a chassis characterized in that it also comprises a member for destroying the vault feet capable of sweeping the surface of said grid designated below said tank while remaining above said grid.

[0005] Patent application EP0196887 describes a discharge device comprising a container having an openwork bottom, one or more material moving members engaging with or lying adjacent the upper surface of the bottom, and drive means for moving the one or more body members through the bottom to push thus the material in the container down through the openings in the bottom.

[0006] Patent application WO2013138926 relates to a system for evacuating biomass from a chamber having at least two walls each corresponding to an associated wall plane, the system comprising: a grid extending between two of said wall planes and forming a bottom of the chamber; a knife having an elongated main blade portion extending between the two of said wall planes, above the grid, the elongated main blade portion having an elongated cross-section oriented parallel to the grid and two downwardly inclined opposite faces each leading to a corresponding opposite cutting edge; the knife having at least two guide elements, each guide element being positioned on a corresponding side of the elongated main blade portion;at least two parallel knife guides, each of the at least two knife guides receiving a corresponding knife guide member, the at least two knife guides cooperating to guide the knife along a knife path oriented parallel to both the grate and the wall as the knife is moved along the knife path; two elongate and flexible pulling members, each connected to a corresponding side of the main blade portion, cooperatively pullable to move the knife along the knife path; such that a portion of the biomass in the chamber is discharged through the grate as the knife is pulled along the knife path.;

[0007] Spanish patent application ES2754823Al proposes a vermicomposting apparatus comprising a structure for housing an organic mixture and earthworms, at least one first grid arranged horizontally and supported on the structure, and cutting means for separating a humus generated from the organic mixture and the worms. The apparatus comprises at least one second grid arranged parallel to the first grid, which divides the structure into a first chamber configured to house the organic mixture and the worms and a second chamber between the two grids and configured to house the humus, so that the first grid is configured to support the humus and the second grid is configured to support the organic mixture and the worms, the cutting means being arranged between the two grids. Disadvantages of the prior art

[0008] In the solutions of the prior art, the mechanism ensuring the movement of the scraper is subject to contact with the biomass, which leads to a risk of oxidation and fouling of the drive parts. Furthermore, certain solutions provide pads to position the height of the scraping blade, which can cause biogages due to jamming.

[0009] Furthermore, the kinematics of the blades of the prior art are relatively complicated, which leads to a lack of reliability. The solution proposed by the patent EP0196887A2 provides that "the scraper 160 comprises a frame 166 running in U-shaped rails 168, 169 and supporting a number of pivoting scraper blade assemblies 171 which lift up during the rearward movement of the frame 166 when they come into contact with a pile of waste 162 on the surface 164. In their forward movement, however, pivoting of the blade assemblies is prevented by contact between the lower surface of the frame 166 and the stop plates 173 mounted on the scrapers. The structure of the hinges (174) is such that they will not be affected by falling waste (see, for example, Figure 15)." These blades are driven by mechanisms in several rotary movements, these mechanisms being immersed in a humid and compact medium, leading to jams and blockages. Solution provided by the invention

[0010] In order to overcome the drawbacks of the prior art, the present invention relates, in its most general sense, to a worm composter comprising a tank having an openwork bottom and at least one movable scraper bar, characterized in that said scraper bar is driven in translation by these two lateral ends, in a horizontal plane at a predefined height relative to the openwork bottom of said tank, by a drive mechanism for said scraper bar arranged outside said tank, below or next to the tank.

[0011] According to alternative embodiments, the worm composter according to the invention also has one or more of the following characteristics: - - it comprises at least one movable transport belt arranged under said bottom openwork to collect mature compost falling when a scraper bar passes towards a recovery area. - the said scraping bar(s) are moved continuously for permanent collection of mature compost. - said tank is of rectangular section and is surmounted by a feed hopper moving continuously above the opening of said tank. - It comprises a cable surrounding the accessible parts of the tank, said cable being connected to a device controlling the shutdown of the entire installation in the event of traction on said cable. - said tank has a closing cover which can be removed during filling. - It includes at least one homogenization device for the biomass contained in said tank. - said drive mechanism consists of a worm screw controlling the longitudinal movement of said scraping blade. - said worm screw is driven by a crank arranged on one of the faces of said tank. Detailed description of a non-limiting example of embodiment

[0012] The present invention will be better understood on reading the following description, concerning a non-limiting example of embodiment illustrated by the appended drawings where:

[0013] [Fig-1] [Fig.l] represents a perspective view of a first example of a sheave installation of a worm composter for individual or collective use

[0014] [Fig.2] [Fig.2] represents a front view of said first exemplary embodiment of a worm composter for collective use

[0015] [Fig.3] [Fig.3] represents a schematic perspective view of the harvesting mechanism of said first example of an individual or collective use worm composter

[0016] [Fig.4] [Fig.4] represents an exploded sectional view in perspective of the openwork bottom and the scraping system of an example of a domestic worm composter

[0017] [Fig.5] [Fig.5] represents a side view of said example of an individual or collective worm composter

[0018] [Fig.6] [Fig.6] represents a perspective view of the perforated bottom and the scraping system of said exemplary embodiment of an individual or collective worm composter

[0019] [Fig.7] [Fig.7] represents a perspective view of a second example of a sheave construction of a worm composter for industrial use

[0020] [Fig.8] [Fig.8] represents a schematic cross-sectional view of said second example of an industrial worm composter

[0021] [Fig.9] [Fig.9] represents a schematic front view of said second example of construction of a worm composter for industrial use. General principle of the invention

[0022] The invention relates to robust and reliable equipment for transforming organic waste not soiled by non-biodegradable materials (kitchen waste, canteen waste, food industry waste, sewage treatment plant sludge, etc.) more generally called biowaste and biomass into natural fertilizer using compost worms. They reproduce the natural process of degradation of organic waste. The worms metabolize the biowaste to produce droppings forming an organic amendment called vermicompost.

[0023] Generally, such equipment comprises a tank (10) opening on the top with a feed opening (11) for biowaste and a perforated bottom (12) for recovering the vermicompost.

[0024] The tank (10) is made up of side walls, front walls, and an openwork bottom; it defines a volume whose upper layer corresponds to the last discharges of biowaste, the intermediate layer corresponds to the active volume where The biowaste is metabolized by the worms and transformed into droppings, and the layer resting on the perforated bottom mainly corresponds to the droppings resulting from this metabolization. Slices of this lower layer are extracted by moving a blade scraping the surface of the bottom to make the droppings pass through the perforated bottom to allow its recovery in an external hopper.

[0025] The invention differs from the prior art in that all of the drive mechanisms for the scraping blade are located outside the tank, either below or on either side of the outer surface of the side walls, to improve the robustness and lifespan of the equipment and to avoid permanent contact of these mechanisms with the wet biomass.

[0026] Earthworms thrive in a humid environment (75 to 80% humidity). Humidity can be controlled by the nature of the biowaste, for example by increasing the amount of peelings to increase humidity, brown cardboard or paper to reduce humidity, or by using nebulizing nozzles to control the humidity of the tank contents.

[0027] The dimensions of the tank are determined to form a height adapted to the migration of the biowaste deposited on the surface into an upper layer where they partially decompose, an intermediate layer in which the earthworms develop and metabolize the biowaste. New layers are added above and the oldest are eliminated below. The first action raises the level, the second reduces it. Thus the grouping of these two actions makes it possible to keep the height of the litter stable and create a continuous flow of material from top to bottom., and a lower layer in which the excrement constituting the vermicompost is found, which is recovered by occasional or continuous sampling using a blade (50) running above the perforated bottom (12).The blades are driven manually using a worm screw or a telescopic jack located outside the tank (10) and operated by flywheels (23, 24) or by a motorized system. In industrial versions, the blade is driven by two chains, assembled on two sprockets located on each side of the module, and operated by a geared motor. Individual or collective worm composter

[0028] Figures 1 to 6 illustrate an example of an embodiment of a worm farm for collective use. It consists of a mobile frame (1) on rollers, the upper part of which is closed by two side walls (2, 3) and two front walls (4, 5) as well as an openwork bottom (12), the whole forming a tank which can be closed by a cover (15).

[0029] A lid or cover (15) is provided to close the tank (10) after filling, in order to preserve the humidity of the biowaste and prevent attacks by birds or other animals.

[0030] The blades (50 to 53) pass through the tank (10) and the side walls by longitudinal slots (16 to 18), and are connected to the drive mechanism by the two opposite ends, outside the tank (10). A recovery container (31, 32) is placed under a hopper (25) arranged under the perforated bottom (12).

[0031] The blades (50 to 53) are movable and driven by a mechanism formed of supports (40) extending longitudinally, parallel to the longitudinal slots (16 to 18), and perpendicular to the blades (50 to 53). These supports have spacers (41, 42) of a height greater than the thickness of the perforated bottom (12). The blades (50 to 53) are fixed, for example by screwing, on these spacers (41, 42). A threaded rod (41) driven by a crank (23) ensures the front-to-back and back-to-front movement of the blades (50 to 53), above the bottom, in a horizontal plane to scrape the bottom (12) of the tank (10) and force the passage of the lower layer of earthworm droppings. Industrial variant

[0032] Figures 8 and 9 illustrate an industrial embodiment variant, using a much longer tank (10), the upper edges of which have rails (62, 63) ensuring the guidance of a feed hopper (55) movable along the tank (10) to distribute the biowaste. The hopper (55) is loaded at one point by a biowaste collector (60), and by a ramp (61) comprising five endless screws for loading the hopper (55).

[0033] The bottom of the tank (10) is perforated and comprises transverse scraper blades, moved by chains arranged longitudinally outside the tank (10). These chains are linked to the lateral ends of the blades (50 to 53), which pass through the tank (10) by longitudinal slots provided on the lateral faces of the tank (10).

[0034] The vermicompost is deposited on a belt (64, 65) passing under the perforated bottom, and pouring the collected vermicompost into a collection bin (66).

Claims

Claims

1. Worm composter comprising a tank having an openwork bottom (12) and at least one movable scraper bar, characterized in that said scraper bar (50 to 53) is driven in translation by these two lateral ends, in a horizontal plane at a predefined height relative to the openwork bottom (12) of said tank (10), by a drive mechanism for said scraper bar (50 to 53) arranged outside said tank (10), below or next to the tank (10).

2. Worm composter according to claim 1 characterized in that it comprises at least one mobile transport belt arranged under said perforated bottom to collect the mature compost falling during the passage of a scraper bar (50 to 53), towards a recovery zone.

3. Worm composter according to the preceding claim, characterized in that said scraping bar(s) (50 to 53) are moved continuously for permanent removal of mature compost.

4. Worm composter according to at least one of the preceding claims, characterized in that said tank (10) is of rectangular section and in that it is surmounted by a feed hopper moving continuously above the opening of said tank.

5. Worm composter according to the preceding claim, characterized in that it comprises a cable surrounding the accessible parts of the tank, said cable being connected to a device controlling the stopping of the entire installation in the event of traction on said cable.

6. Worm composter according to claim 1 characterized in that said tank comprises a closing cover capable of being removed during filling.

7. Worm composter according to claim 1 characterized in that it comprises at least one homogenization member (60) for the biomass contained in said tank.

8. Worm composter according to claim 1 characterized in that said drive mechanism is constituted by a worm screw controlling the longitudinal movement of said scraping blade.

9. Worm composter according to the preceding claim, characterized in that said worm screw is driven by a crank arranged on one of the faces of said tank.

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