ES2696983A1 - Installation for the reduction of residues from the fumes or gases of drying of vegetal residues, and procedure carried out by said installation. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Installation for the reduction of residues from the fumes or gases of drying of vegetal residues, and procedure carried out by said installation. The installation comprises a combustion chamber or generator of hot air (1) for heating gases, a unit for drying plant residues, consisting of a drying chamber on which hot gases are circulated, and characterized by comprising in addition, a post-combustion unit of the gas phase and of the particles entrained by it, coming from the separating unit, in which said post-combustion unit is a regenerative oxidation chamber. The process includes the heating of drying gases, conduction through a chamber for drying the gases and the vegetable residues, conduction of the "dirty gases" to a regenerative oxidation chamber, introduction of the "dirty gases" by a entry way of the regenerative oxidation chamber, after-combustion of the "dirty gases" at high temperature, extraction of the gases by the exit route of the regenerative oxidation chamber, and expulsion to the environment of the clean gases. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Installation for the reduction of residues from the fumes or gases of drying of vegetal residues, and procedure carried out by said installation.

The present invention has as an object an installation that allows to reduce solid and gaseous residues produced by the drying of plant products of different natures, such as those coming, without limitation, from olive pomace, grape marc, alfalfa, among others. However, the explanation with reference to the olive pomace will be explained, since it is its main application, although the invention is also applicable to the treatment of other residues of vegetable origin, whose accumulation or uncontrolled burning is of any undesired point.

Background and state of the art

The olive oil is made by pressing and crushing the olives to obtain the oil.

Once the olive oil is extracted, as a by-product olive pomace is obtained, with a pasty consistency; For the extraction of pomace oil the pasty mass of pomace must be dried.

For drying, a combustion chamber or hot air generator is used that can use different sources of energy, but usually employs orujillo, although fossil fuels, or others, could also be used. The gases of the boiler are generally raised above 800 ° C and mixed with ambient air to lower their temperature, they are passed through a drying chamber; Generally this drying chamber will be a trommel or rotating chamber that transports and turns the wet pomace until the degree of humidity is reduced to a desired threshold. At the same time that the pomace is dried, the hot gases that dry it carry a large amount of organic and inorganic matter in a solid state, liquid (in suspension in the form of microdroplets) and gaseous.

From the drying air of the pomace, which, as has been said, carries a large quantity of particles, solid matter of a certain size is usually separated in the sedimentation chamber and subsequently cyclones. The remaining minor solid fractions are, however, entrained by the gases.

Thus, the gases coming from the combustion for the drying of the marc along with all the materials that they drag, that could not be separated in the cyclones, can not be filtered, since any filter that is used is going to be saturated quickly ( in the order of hours or days), which makes it economically and technically unfeasible, and in case these gases are not filtered, they can not be emitted into the atmosphere due to their high polluting nature.

One of the problems that arise in the installations orujeras is the emission into the atmosphere of polluting fumes, usually with a high proportion of organic matter, as well as ash and other solid particles. Both the regulations and the technology are aimed at reducing the amount of contaminants.

A large part of the fumes from the combustion of the solid fraction, as indicated, are formed by solid or gaseous organic particles, with a high molecular mass, and by ashes and other inorganic particles, whose emission should be avoided.

To try to reduce the polluting character of fumes, different operations have been carried out:

Placement of filters in the smoke outlet;

Cartridge or fine mesh filters;

If the filters have a large mesh size, these filters are not capable of retaining most of the contaminating particles; On the other hand, if the mesh size is small enough, the solid charge, the droplets of liquid organic matter and the gases that could be condensed from the fumes quickly clog it, the installation must be stopped for replacement or cleaning with a large frequency;

The frequency in the clogging of the filters makes this application not economically or technically viable, since in addition to the same filters it would require a subsequent treatment of said filters for cleaning. Water filters

These filters, although they may have a certain capacity for capturing particles, the water used is contaminated with the particles that you want to avoid sending to the environment, so that there is a problem similar to the previous case, requiring large amounts of water, which again makes practical application unviable.

Post-combustion;

the combustion at high temperature of the waste obtained does allow the elimination of all the organic matter contained in the smoke, limiting the waste to inorganic, inert material, which can even be used as a raw material in different industrial or agricultural applications; However, the energy input needed to heat the smoke at temperatures close to 900 ° C requires a very high energy consumption, and also, consequently, the emission of a large amount of greenhouse gases into the atmosphere. This makes the use of a conventional post-combustion for the treatment of vegetable waste unfeasible.

ES 2156716 describes a process for the drying and treatment of disposable olive pomace, which includes the steps of mixing and homogenization, centrifugation and obtaining a liquid fraction based on vegetable water and a solid one with a low moisture content. Describe the treatment and use of the liquid phase. Unlike said invention, the invention that we describe describes an installation and a method for the treatment of the solid phase.

Description of the invention

The present invention relates to an installation for the reduction of waste from the combustion fumes of vegetable waste, in which said fumes entrain a large amount of organic matter in the solid, liquid and gaseous state in addition to inorganic ash; the installation comprises a pomace drying unit; said drying unit is normally formed by a combustion chamber or hot air generator that conducts the hot gases to a drying chamber, normally a turner or "trommel" that heats the flow of material to be dried, extracting steam from it , and other gases, and dragging other particles, many of them with a high fat content.Thus, we will call "dirty gases" those coming from the drying process; the invention is characterized by further comprising a unit for after combustion of the "dirty gases", said post-combustion unit being formed by a regenerative oxidation chamber provided with a combustion chamber which overheats the high temperature exhaust gases, normally above of 650 ° C, said regenerative oxidation chamber being formed by two or more access bodies that constitute respective entry / exit routes to the combustion chamber of said regenerative oxidation chamber.

The access bodies alternate the input function of the cold gases with the output function of the superheated gases. Each access zone or body is formed by an access lattice normally formed by sets of perforated ceramic bodies. When accessing the dirty gases to the inlet body, these are heated to reach the combustion chamber (afterburning) as hot as possible, always below the maximum combustion temperature; Once the maximum temperature is reached, the organic particles entrained burn and inert so that they cease to be contaminants, so that the "dirty gases" after the combustion become "clean gases" formed mainly by CO2 and H2O, and compounds inorganic (ashes) The clean gases leave the combustion chamber by an outlet body, which is heated by the passage of said clean gases, that is to say, the entrance zone cools down when yielding heat to the dirty gases of inlet that they are heated, and in the exit zone the opposite effect takes place, that is to say, the zone of entrance warms up by the step of the hot clean gases coming from the combustion chamber, while said clean gases are cooled. function of the temperatures in different points of the regenerative oxidation chamber, the entry and exit zones are swapped, the entrance zone being an exit zone, and vice versa.

It is foreseen within the scope of the invention the use of regenerative oxidation chambers of three or more ways, with operation analogous to that described, in which the third way has alternates with the previous ones or exerts an intermediate transit function.

In order to reduce particle emissions, the installation is intended to include a device for filtering the gases coming from the post-combustion, the solid residue of which is substantially inorganic matter.

In a particular embodiment it is provided that the filtering device is a bag filter, although any other extrinsic purification system must also be considered within the scope of the invention.

It is provided that the regenerative oxidation chamber is provided with at least one sub-chamber of combustion in the cold zone (inlet zone for dirty gases and / or exhaust gases), in which the temperature can be raised sufficiently to produce a catalytic or pyrolytic cleaning of accumulated and adhered waste in said area. The combustion in this area, especially in the area that at that moment has the function of entering the hot gases, will be activated when a cleaning is necessary, without need to stop the rest of the installation, and decreasing the energy requirements in the main combustion chamber.

The invention also relates to a smoke treatment process using the installation described above.

The procedure includes the following stages:

• Heating of gases in a combustion chamber or hot air generator and supply of hot gases to a drying drum;

• Supply of vegetable organic waste to the drying trmel of said waste, leaving the "dirty gases" that carry gases and other particles from the drying process;

In which according to the invention the following additional steps are carried out:

• Conduction of "dirty gases" to a regenerative oxidation chamber;

• Preheating of the gases in the entrance area of the regenerative oxidation chamber;

• Heating of the "dirty gases" in a combustion chamber of the regenerative oxidation chamber, up to a temperature, according to a preferred embodiment, of between 650 ° C and 1050 ° C, and particularly between 750 ° C and 950 ° C

• Cooling of the gases and transfer of heat to the exit area of the regenerative oxidation chamber;

• Alternating the entrance zone and the exit zone of the regenerative oxidation chamber, remaining as the exit zone and entrance zone, respectively; or in the case that the regenerative oxidation chamber has more than two paths, alternating with the rest of the zones;

For the heating of the gases can be used orujillo, that is to say, the pomace once the oil has been extracted, or other fuels.

Preferably filtering of the exhaust gases before their emission to the outside.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to illustrate the explanation that will follow, we attach to the present descriptive a sheet of drawings, in which in a single figure is represented, by title example and without limiting character, the essence of the present invention, and in which the following can be observed:

Figure 1 shows a schematic view of a pomace treatment plant to which, according to the invention, a regenerative oxidation chamber has been incorporated.

We can see in this figure the following reference signs:

1 Combustion chamber or hot air generator

2 drying trómel;

3 Set of sedimentation chamber and cyclones separating the liquid and solid fraction;

4 Regenerative oxidation chamber;

5 Filtering device

6 Fireplace

41 combustion chamber in the regenerative oxidation chamber

42 ways or zones of entry / exit of gases in the regenerative oxidation chamber.

43 Sub-chamber of combustion, for the cleaning of the ways or zones of entrance / exit of the gases in the regenerative oxidation chamber;

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

The invention described consists of an installation for the reduction of residues from the fumes of the combustion of plant residues, and particularly those from the extraction of the pomace oil, of which they comprise the following elements:

A combustion chamber or hot air generator (1);

A trómel (2) of drying the marc;

A set of sedimentation chamber and cyclones (3) for separating the solid and liquid fractions from the pomace;

A chimney (6) for evacuating gases;

And that according to the invention is characterized by understanding, in addition:

A regenerative oxidation chamber (4); Y

Preferably an extrinsic purification system (5) such as a bag filter. The invention also relates to a process for the reduction of waste from fumes or gases for drying plant residues, carried out by said installation.

As indicated above, the combustion chamber or hot air generator (1) which is fed with a fuel such as olive oil, supplies hot gases to the pomace drying chamber, usually a trommel (2) to which the fuel is fed. orujo mixed with water, for drying; the hot gases, when drying, volatilize a large amount of matter, besides water vapor, and also drag other particles, remaining as "dirty gases." The dirty gases are introduced in a regenerative oxidation chamber (4) comprising a chamber of combustion in which an afterburning takes place, and which has at least two zones or paths (42): a pathway with a gas inlet function, and a way out of the gases.According to a preferred embodiment, the temperature at The gas in the combustion chamber of the regenerative oxidation chamber rises between 650 ° C and 1050 ° C, and particularly between 750 ° C and 950 ° C. Each of the ways is formed by a body of large mass, provided with a large number of through holes, so that the drying gases reach the entrance to the cold, and by the thermal mass of the installation under operating conditions, these gases are heated and cooled or zone of inlet, until the gases reach the combustion chamber (41) that has the regenerative oxidation chamber. In said combustion chamber (41) a post-combustion of the "dirty gases" is carried out with all the volatiles and particles that it carries, burning the compounds and destroying their oily or bituminous character.

Thus, after the post-combustion process, the hot gases are conducted to the zone or exit route of the regenerative oxidation chamber, so that said gases give up heat to said zone or exit route.

Cyclically, when the inlet zone has cooled down to the specified temperature and / or the hot zone has been heated up to the specified temperature, the position is inverted so that the entry zone or path is an exit zone or path, and the zone or way of exit happens to be an area or way of entrance.

When the regenerative oxidation chamber (4) has more than two paths (42), they will alternate or combine in the convenient manner.

It is envisaged that the regenerative oxidation chamber is provided with at least one combustion sub-chamber (43) in which the cleaning of the gas inlet / outlet areas or pathways can be carried out. This combustion sub-chamber (43) will be placed in the dirty gas entry zone or path, and will only be used when a catalytic or pyrolytic cleaning is necessary.

After the exit of the zone or exit route of the regenerative oxidation chamber, the "clean" gases are preferably led to an extrinsic purification system as a filtering device, for example, a bag filter, so that, since the material is not trapped by them, particularly oil or bituminous, they can be periodically cleaned easily by mechanical means, avoiding the problem posed at the beginning of this document.

At the outlet of the filter, the gases are led to a chimney (6) for the evacuation of gases and gases, having verified that the composition of the gases emitted is within the parameters admissible by the regulations.

Claims (7)

1. - Installation for the reduction of residues from the fumes or drying gases of vegetable waste, particularly from the drying of the marc, which comprises: A combustion chamber or hot air generator (1) for gas heating; a drying unit for vegetable waste, consisting of a drying chamber, usually a trommel (2) on which the hot combustion gases are circulated; characterized by further comprising a post-combustion unit of the gaseous phase and of the particles entrained by it, coming from the separating unit, in which said post-combustion unit is a regenerative oxidation chamber. 2. - Installation for the reduction of waste from the fumes or drying gases of vegetable waste, according to claim 1, characterized in that the regenerative oxidation chamber has at least two zones or paths (42): An area or way of entry; A zone or exit route; And because it is provided with an alternative entry / exit access, so that cyclically the area or way of entry becomes the zone or exit route, and the zone or exit route becomes the area or route of entry. 3. - Installation for the reduction of waste from the smoke or drying gases of vegetable waste, according to any of claims 1 to 2, characterized in that it also comprises an extrinsic purification system as a filtering unit for the inorganic solid particles of the salient gases from the regenerative oxidation chamber. 4. - Procedure for the reduction of waste from fumes or gases for drying plant residues, carried out by the installation of claims 1 to 3, characterized in that it comprises the steps of: Heating in an oven gases for the drying of vegetable waste; Driving through a drying chamber, usually a trommel, of the gases and plant residues; Conduction of "dirty gases" from the drying of plant residues to a regenerative oxidation chamber; Introduction of "dirty gases" through a pathway or zone of entry of gases, of the regenerative oxidation chamber; Post-combustion of "dirty gases" at high temperature; Extraction of the gases through the zone or exit route of the regenerative oxidation chamber; Y Expulsion to the environment of clean gases. 5. - Procedure for the reduction of waste from the smoke or drying gases of vegetable waste, according to claim 4, characterized in that the temperature at which the gases rise in the combustion chamber in the regenerative oxidation chamber is between 650 ° C and 1050 ° C, and particularly between 750 ° C and 950 ° C. 6. - Procedure for the reduction of waste from the smoke or drying gases of plant waste, according to any of claims 4 to 5, characterized in that it also comprises the cyclic alternation of the areas or ways of entry and exit of the chamber of regenerative oxidation. 7. - Procedure for the reduction of waste from the smoke or drying gases of plant waste, according to any of claims 4 to 6, characterized in that it also comprises the purification of the gaseous effluent by extrinsic methods prior to the gases before the expulsion to the environment.