FR2673621A1 - Device intended for the treatment of organic residues and methods of use - Google Patents

Abstract

Plant intended for the aerobic fermentation treatment of organic residues or waste, such as vegetable waste, water purification station sludge or industrial or household organic waste, characterised in that it comprises a group of automatically filled silos-channels or reactors, and a ventilation and moistening system which are servo-controlled by a programmable automatic device permitting the composting under controlled conditions and the partial dehydration of the products obtained.

Description

DESCRIPTION
The present invention relates to an installation intended for the treatment of organic residues by a thermogenic aerobic fermentation phase according to a composting process.

existing composting facilities require either extensive and frequent handling (rustic windrow composting facilities with turning or forced ventilation), or complex infrastructure (equipment and civil engineering).

The present installation uses the composting technique in controlled forced ventilation in fixed reactors having the advantages of reducing numerous handling of products, optimizing the duration and quality of composting by controlling ventilation and ensuring a finished product. quality.

the organic residues to be treated are incorporated mechanically into the reactor after a pretreatment, either in admixture with a carbonaceous substrate (such as wood chips, corn cobs or bark), or after pretreatment (grinding, etc.). The reactor is then put into aerobic fermentation for a minimum of 2 to 3 weeks (thermogenic reaction).

The ventilation system is then controlled by the temperatures of the heap in composting by means of thermal probes placed in the heap (or in the ventilation ducts) connected to a programmable controller.

The ventilation of the reactors during this so-called "composting" phase can be done either by suction of the air from the reactors, or by blowing outside air into the reactor. The ventilation is triggered when the average temperature of a reactor is above a high temperature threshold varying according to the products between 50 and 60 OC.

Depending on the products to be treated (case of highly woody or porous waste), a control of the air humidity passing through the reactor may be carried out and thus trigger, via the programmable controller, a humidification system by nebulization or watering by aspersion.

At the end of this phase, the reactor is placed in a permanent regime of insufflation of outside air, preheated or not. The breakdown may take account of EDF tariff periods.

This so-called "ripening-drying" phase aims to stabilize and dry the product or the mixture of products. Depending on the treatment objectives, this phase may be optional or have a duration of 2 to 5 weeks.

The product can then be sieved. The fine fraction corresponds to the finished product likely to be marketed, the coarse fraction (in the case of mixing) can be recycled as a structuring at the head of the station.

According to our invention, the installation consists of - a pre-treatment of the waste to be treated (grinding, mixing, ...) using fixed or mobile station equipment; - a composting and maturation-drying workshop consisting of a set of reactors type siloscouliers fed automatically comprising: * * an air diffusion system and a channel for collecting exudates included in the base slab; * a programmable controller connected to temperature probes placed in the heap or in the ventilation ducts and triggering the ventilation system from a predetermined temperature threshold; * a humidification system by nebulization or sprinkling of the reactors controlled by the programmable controller via a hygrometric probe measuring the relative humidity of the air passing through the reactor, an automatic supply system for the reactors by screw or by conveyor belt.

- a product finishing workshop by sieving and / or bagging.

the various workshops can be located in a covered building.

By way of nonlimiting example; an embodiment of an installation according to the invention has been described below
FIG. 1 corresponds to a block diagram of the treatment installation according to the invention.

The installation includes a mixing or preparation area for products equipped with a mixer supplied with components to be mixed previously stored in buffer hoppers.

The mixture or product to be treated is then led to the composting area by a conveyor belt or a conveyor screw and automatically distributed in the composting reactors.

the composted products can then be sieved before storage or disposal.

Figure 2 illustrates by way of example, the equipment necessary for the proper functioning of the installation.

Let us remember that the product distribution system can be of the conveyor screw or carpet assembly type, this allows the feeding of all the boxes by controlled rotation of this system around a pivoting axis.

This supply system is controlled by a programmable controller which manages the filling of the reactors (measurements of filling angle and height in the reactors).

These reactors can consist of wooden or concrete corridor silos (prefabricated or poured on site) comprising an air diffusion system included in or on the base slab, a humidification system for the air circulating in the reactors.

This reactor is used for the "composting" phase and the "maturation-drying" phase, this in the static phase without turning the waste to be treated.

The ventilation system consists of the diffusion system of the reactor and fans controlled by the automaton by means of thermal probes incorporated in the materials to be treated (surface or depth).

 The installation is intended for the treatment in silos or aisle reactors of organic residues, such as sludge from water treatment plant, livestock or agricultural waste, organic waste or residues from industries (agro-food or other ) or woody organic waste from processing activities which includes a composting and dehydration workshop using the aeration and / or humidity control of the products to be treated in order to optimize the microbiological reactions necessary for the smooth running of the treatment.

 The installation includes a mechanized and / or automated feed system for rotary distribution type siloscoulers, thus avoiding penetration into the reactors with the materials to be treated for filling.

Caption figure 2:
I - compacted stabilized area.

 II- concrete area limit.

 ffi - theoretical limit for depositing waste.

 IV - internal compartment separation wall.

 V - spray bars.

 VI - air distribution grating inserted in the concrete slab.

 VII - external compartment separation wall.

 VIII- electrical cabinet for general control.

 IX- stationary fan used for the composting phase.

 X - arrival of the materials to be treated (crushed hem mixed), conveying system.

XI - articulated conveyor system feeding the boxes (other option: screw with hatch
electric).

 MI - conveyor running wall.

Claims (4)

REVZDICATIONS 1- Device intended for the treatment of organic residues comprising a pretreatment of waste (X) characterized in that it comprises boxes (in, VIL XII) fed in a rotary manner by an automated mechanical system (XI) pivoting about an axis . 2- Device according to claim 1 characterized in that it comprises a ventilation system constituted for each box by a fan (IX) distributing the air in a gutter included in the base slab and covered with a grating (Vit) . 3 - Device according to claim 1 characterized in that it comprises a programmable controller (VIII) which has the function of controlling the automatic supply of the boxes and the ventilation of the boxes and the humidification system of the materials to be treated (V) . 4- A method of implementing the device according to claims l to 3 characterized in that it comprises  - pre-treatment of materials  - a mixture with a carbon substrate  - aerobic fermentation in the reactor  - ventilation started when the average reactor temperature is above one  high variable threshold according to the products  - a maturation - drying to stabilize and dehydrate the composted product 5- Method according to claim 4 characterized in that it comprises a control of the humidity of the air passing through the reactor by a humidification system 6- Method according to claim 4 characterized in that it comprises a sieving of the product at the end of the drying maturation phase making it possible to obtain a fine fraction corresponding to the finished product and a coarse fraction which can be recycled at the head of the station.