LU93118B1 - Device for homogenizing a mass of organic waste - Google Patents

Abstract

The invention relates to a device (100) for homogenizing a mass of organic material for composting. It comprises a mixing tank (2) of said organic materials equipped with a rotor (3), means for filling (5) and unloading (7) of the tank (2), introducing means (13) of additives and means for measuring (11) the physical, physico-chemical and biological characteristics of the kneaded materials, the measuring means (11) being mounted retractable relative to the kneading tank (2). Application to the preparation of a composting material.

Description

The technical sector of the present invention is that of mixing systems of organic materials of various origins for composting.

It is known in the field of organic waste disposal machines for drying, and / or composting materials with or without the addition of bacterial kit, to reduce the volume by removal of water (dehydration) and / or supposed reduction of the organic fraction.

However, it has been found that the composting of organic materials presents many problems. Thus, the composted product suffered from the following drawbacks: - lack of stabilization (respirometric tests) and requiring a maturation phase, - presence of coarse residues, - loaded liquid discharges with levels of chemical oxygen demand (COD) and biological demand 5-day increase in oxygen (BOD5) over non-domestic wastewater discharges, - lack of qualification as composted products due to physicochemical and microbiological results, - high organic matter content, - a low mineral content, - a relatively low Carbon / Nitrogen ratio, - considered as waste for "sechats".

Therefore, the destination of the outgoing products is random because: - they do not meet the standards for composts, amendments (NFU 44-051 and NF U 44-095) and organic fertilizers (NFU 42-001), they must undergo a regulatory reprocessing (collection and disposal) or private domestic use they involve a spreading plan or a strictly individual use.

The composting facilities benefit from a classification under ICPE (classified installation for the protection of the environment) or prefectural waiver.

Moreover, these installations offer little adaptability to efficiently compost organic products of various origin such as complex sugars (cellulose, lignin ...) given the number of physicochemical and biological parameters to correlate in order to achieve a successful outcome. compost usable.

The applicant has therefore carried out studies to overcome the aforementioned drawbacks and to provide a quality composting material. It has been noted that the quality of the final product depends firstly on the quality of the starting mixture: carbon / nitrogen ratio, homogeneity of the mixture, structure, texture, pH, oxygen vacancy rate, humidity, temperature, absence of substances anti-fermentative or anti-germinative, natural or resulting from human activity (agricultural or not).

The purpose of the present invention is therefore to provide a premix of the composting material for subsequently composting by providing a device for homogenizing the raw materials. The subject of the invention is therefore a device for homogenizing a mass of organic materials with a view to its composting, characterized in that it comprises a mixing tank for said organic materials equipped with a rotor, filling and unloading means of the tank, means for introducing additives and means for measuring the physical, physico-chemical and biological characteristics of the kneaded materials.

According to a feature of the device, the measuring means are mounted retractable relative to the mixing tank.

According to another characteristic of the device, the measuring means consist of probes for measuring the hygrometry rate, the redox potential, the pH, the oxygen content and the temperature.

According to yet another feature of the device, it comprises means for extracting the mass of the kneaded materials.

Advantageously, the extraction means are constituted by a worm and a guillotine valves.

According to yet another feature of the device, it comprises a water supply of the tank.

According to yet another feature of the device, it comprises a nutrient distributor, a mineral distributor and a structuring distributor.

According to yet another characteristic of the device, the tank is fixed on a support equipped with means for measuring its mass.

According to yet another feature of the device, it comprises a control unit of its various components.

A first advantage of the device according to the invention lies in the control of the parameters for starting the composting.

Another advantage of the device according to the invention lies in its automated driving to prepare a homogeneous mixture of high quality, within 24 to 72 hours, and this, for all types of organic materials.

Yet another advantage of the device according to the invention resides in the control of the physical, physicochemical and biological characteristics of the mixture made, which subsequently makes it possible to start the composting process in a conventional composting installation. The invention will be better understood on reading the additional description which will follow of an embodiment given by way of example in relation to drawings in which: FIG. 1 is a view showing the various elements of the device according to FIG. FIG. 2 is a view of the device according to the invention ready for operation, FIG. 3 illustrates the computer control of the device according to the invention, FIG. 4 shows the variations of the pH and of the temperature during the composting organic matter according to MUSTIN, and - figure 5 shows the rational determination of the carbon / nitrogen and water / air ratio according to JOLIET and HOLLAND.

In Figure 1, there is shown the device 100 according to the invention in an exploded view illustrating its various elements.

The device comprises a frame 1 on which is fixed a tank 2 for mixing organic waste. In the figure, we see that the tank 2 consists of two rectangular side plates 25 extended by a portion V. These side walls 25 are connected by two longitudinal walls 26 whose lower part is substantially arcuate without surface discontinuity . Thus, the organic waste is naturally directed to the bottom of the tank 2 and kneaded without difficulty. The longitudinal walls are equipped at the bottom with heating elements 10.

A rotor 3 is inserted into the tank so as to be rotated by means of a motor 4 equipped with a gearbox. This rotor 3 consists of a frame 20 secured to the central axis 21 at its ends and via a central arm 22. The frame 20 thus delimits two symmetrical rectangular frames whose vertices are connected by 23. In the figure, we see that the frame 20 has eight arches 23. This structure allows efficient mixing as will be explained below.

The tank 2 is closed by a lid 24 comprising a hopper 5 for loading the waste to be composted, nozzles 13a-13c for the introduction of nutrients, a water supply 14 and an opening 15 for discharging the waste. 'air.

A worm 7 is inserted into a housing 27 open towards the inside of the tank 2 for the disposal of waste after treatment. This screw 7 is rotated at one end in both directions by a motor 8 equipped with a reducer and has at the other end an outlet 6 of treated waste and a gate valve 9.

A measuring means 11 is attached to the tank 2 and is provided with various probes, for example five 28a-28e. It goes without saying that these probes are retractable during operation of the rotor 3 so as to avoid any interference during the rotation of this rotor. The measurements made by these probes 28 will be explained below.

The support 1 of the tank 2 is equipped with sensors 12 for measuring the mass of waste after treatment. The entire device is controlled and regulated by a programmable unit 29 described in connection with FIG.

FIG. 2 shows the device equipped with its various components and it can be seen that it is in the form of a compact assembly whose dimensions are adapted according to the needs of the volume of waste to be treated.

In Figure 3, there is shown schematically the programmable unit 29 in relation to the various components to be controlled. Thus, the unit 29 controls: - the rotation in both directions of the rotor 3 and the stop thereof, the control output of the probes 28 and their retraction concomitant with the rotation of the rotor 3, the introduction via the nozzles 13 of the necessary fraction of the nutrients during the waste treatment, - the opening and closing control of the guillotine valve 9, - the control of the heating means 10, - the supply of water via the pipe 14.

The device according to the invention is used in the following manner or in an equivalent manner. The unit 29 is first programmed to control the different equipment of the device according to the invention according to the type of waste to be treated.

Indeed, the composting know-how starts in the mixing of the waste to be composted, because it is the elements of control of the startup which will allow in fine the 4 phases represented in figure 4 of a good composting to know:

Phase A: metabolization of simple soluble elements (simple sugars, proteins, lipids ...) of waste,

Phase B and C: degradation of complex sugars (cellulose, lignin ...) of waste,

Phase D: intervention of the scavenger fauna (worms, mites, collembolans, insects, myriapods).

These three known phases are illustrated in FIG. 4 which is a representation according to MUSTIN of the evolution of the temperature and the pH within the mass to be composted.

However, no composting preparation machine for subsequent composting exists on the market and that is why composting waste is not valued as it should be. All the equipment of the homogenizer device according to the invention is managed by the computer unit 29 and makes it possible to comply with the parameters initiating the three aforementioned phases (A / BC / D) after the output of the waste treated in the device. These elements are, as previously described, the interchangeable rotor and its alternative operating and stopping periods and its reciprocating direction of rotation, the retractable probes for measuring the oxygen, the redox potential, the temperature, the hygrometry, the pH.

During waste treatment, the probes 28 are immersed at a fixed time within them and retract.

Depending on the measurements made by retractable pH and ORP probes, temperature and hygrometry, IT management allows 1) to provide o + nutrients and / or o + structuring and / or, o + of minerals, thanks to the hoppers envisaged for this purpose, 2) to add water thanks to the provided food for this purpose, 3) to modify the cycles of temperature in duration and intensity, 4) to modify: a . the direction of rotation of the rotor (duration in one direction, duration in the other), b. the on-off cycles of the rotor.

Structurizers are products added to the mass when it is too liquid, such as sawdust, straw flour or other (low dryness). Hygrometry is an indicator of humidity and therefore of dryness.

Oxygen level

An oxygen deficiency must be respected because any aerobic organism consumes oxygen to oxidize the organic compounds that serve as food. Gaseous oxygen content is defined as the percentage of oxygen in the air of "voids" because it plays a key role in the aerobic biological treatment of solid waste. The higher the percentage of gap space, the easier air circulation is. The aerobiosis is maintained as long as the oxygen level does not drop below 5%, the actual limit of anaerobiosis being less than 1%. The needs of aerobic microorganisms evolve during fermentation. These needs are at the maximum at startup during the first phases of organic matter degradation. The gradual disappearance of this fraction causes a proportional decrease in oxygen requirements until maturation where a low residual consumption is still recorded. Thus, an optimal composting is obtained in the first phases for values of 30 to 36% of gaps in the mass).

Thus, when the oxygen measurement probes and the redox potential are immersed in the mass of waste regularly the control unit 29 will modify the settings of the rotor cycles 3 (direction of rotation, on-off periods) of the opening of the hopper 5 and feeding by the distributors 13 of minerals to meet this gap oxygen content.

Humidity level

The optimum moisture content for a given substrate is determined by the maximum gap rate that does not result in inhibition of microorganism activity. It is not so much the total amount of water that counts as its availability for microorganisms. • Bacteria and actinomycetes Hr> 0.93 • Hr mushrooms> 0.61

For example a pile of compost, which climbs poorly in temperature due to excess moisture due to a high percentage of water and little space gap, quickly loses its heat.

By a process similar to the previous one, the programmable unit 29 controls the modification of the settings of the heating means 10, the water supply 14, the hopper supply 5 and the mineral distributor 13.

PH control

The optimum pH range for organic degradation is once again that of optimal life conditions of microorganisms which is about 7.

The pH measuring probe is dipped at regular intervals into the bulk of the waste to modify the setting of the feed of the hopper 5 and the introduction of the minerals by the distributor 13.

Physicochemical conditions

Carbon is the main constituent of organic molecules. During active aerobic fermentation phases, microorganisms consume 15 to 30 times more carbon than nitrogen in the substrate. The carbon / nitrogen ratio therefore decreases constantly during the degradation. Nitrogen requirements are therefore a function of the content of easily biodegradable carbonaceous materials by introducing different fractions of waste.

For this purpose, the mass variation information given by the weighings and the oxidation-reduction / pH variations given by the probes is used. The variations in mass correlated with the parameters of the medium (+/- reductant or oxidant) and with changes in pH trigger, depending on the case, the addition of nutrients and / or wastes to be mixed. All of these operations will make it possible to obtain a product leaving the device according to the invention to form a windrow that is perfectly conducive to subsequent composting. The objective is to favor a good subsequent evolution of the composting phases illustrated in Figure 4 and the C / N and water / air ratios illustrated in Figure 5.

These physicochemical conditions are regulated by the programmable unit 29 to modify the settings of the heating 10, the water supply 14, the feed of the hopper 5 and by dosing minerals, nutrients and rotor cycles 3 (direction of rotation, on-off periods).

weighing

The permanent weighing of the waste treated with the sensors 12 makes it possible to check the stability of the weight and to homogenize the treated mass and thus to recover this treated mass in due time in view of its subsequent external composting.

The mill performed by the rotor 3 avoids the final presence of macro-waste.

Sequential adjustments are provided according to the case and the needs: simultaneity, alternating, coordinating.

The easy change of the rotor 3 offers an easy adaptability of its structure to the different potential products to be prepared (density, physicochemical properties, viscosity, dryness, etc ...).

Claims (10)

1. Device (100) for homogenizing a mass of organic material for the purpose of composting, characterized in that it comprises a mixing tank (2) of said organic materials equipped with a rotor (3), filling means (5) and unloading (7) of the tank (2), introduction means (13) additives and measuring means (11) physical, physicochemical and biological characteristics of the kneaded materials. 2. Device (100) for homogenizing a mass of organic materials according to claim 1, characterized in that the measuring means (11) are mounted retractable relative to the mixing tank (2). 3. Device (100) for homogenizing a mass of organic material according to claim 2, characterized in that the measuring means (11) are constituted by probes (28a-28e) of the hygrometry rate, the redox potential , pH, oxygen level and temperature. 4. Device (100) for homogenizing a mass of organic material according to any one of claims 1 to 3, characterized in that it comprises extraction means (7, 9) of the mass of kneaded materials. 5. Device (100) for homogenizing a mass of organic material according to claim 4, characterized in that the extraction means are constituted by a worm (7) and a guillotine valves (9). 6. Device (100) for homogenizing a mass of organic material according to any one of the preceding claims, characterized in that it comprises a feed (14) in water of the vessel (2). 7. Device (100) for homogenizing a mass of organic material according to any one of the preceding claims, characterized in that it comprises a nutrient distributor (13a), a mineral distributor (13b) and a structuring distributor ( 13c). 8. Device (100) for homogenizing a mass of organic material according to any one of the preceding claims, characterized in that it comprises a control unit (29) of its various components. 9. Device (100) for homogenizing a mass of organic material according to any one of the preceding claims, characterized in that the tank (2) is fixed on a support (1) equipped with measuring means (12) of its mass. . 10. A method for homogenizing organic waste using the device according to any one of the preceding claims, characterized in that it comprises the following steps: - to change the rate of oxygen deficiency, is measured using of a probe the amount of oxygen and the redox potential and this rate is adjusted by modifying the settings of the rotor cycles (3), and the opening of the hopper (5) and the supply by the distributors ( 13), of minerals, - to modify the pH, the pH of the mass of waste is measured by means of a probe and the heating means (10), the water supply (14), the feed hopper (5) and the mineral distributor (13), to modify the physicochemical conditions, the quantity of nitrogen is measured by means of a probe and the introduction of additional fractions of waste is required to increase the proportion of carbonaceous material, - all the measurements by the probes being carried out when stopping the rotor (3).