ES2791575B2 - Solid burner, horizontal flames without smoke and system for the use of the heat of combustion - Google Patents

Description

DESCRIPTION

Solid burner, horizontal flames without smoke and system for the use of the heat of combustion

Technical sector

Due to the effects generated, the invention belongs to the sectors:

1) Energetic

2) Environmental

Background of the invention

At the beginning of the use of solid fuels, wood, coal, etc., and still in our days, bonfires were formed with a pyramidal accumulation of fuels and an air intake towards the center of the base of the pyramid. By closing or opening this inlet, the intensity of the combustion was controlled. This arrangement remains to this day in traditional combustion systems. The method, which was used to heat the premises and to dry traditional products, vegetables, sausages and others, remains in our culture as an ancestral sample. There is a tendency to abandon this type of customs due to the energy waste of the heat generated by combustion, as well as the risk of generation of unhealthy gases for humans and animals.

In the recent state of the art of the system, the solids are introduced into the combustion chamber, through a frontal-lateral and horizontal entrance to it. At the base of this chamber there is a grill that supports and supports the fuels during combustion. These are introduced into the area where the combustion takes place, as the fuel is consumed. The most suitable method is the placement of the fuels in the upper part of the chamber, in the space that is left free by the descent that its combustion supposes. In this way, the generation and subsequent distribution of heat to the places in need is achieved. The grill also serves to remove the ashes that had not been gasified, when they passed to the bottom, accumulating in the place called the ashtray. Periodically, the operator cleaned the ashtray and removed the ashes.

When the fuel is of various origins or of different properties, such as pine logs with their shell, or the shell itself, combustion is very difficult and sometimes explosive. Moisture other than solids also affects it negatively, generating temperature variations in combustion.

The supply of oxygen from the air as an oxidizer for combustion is carried out through two inlets and of two types according to their disposition. The lower one by passing through the fuel support grill and the upper one by means of the fuel introduction door. The upper entrance feeds oxygen to the fire from its side and the bottom entrance feeds the fire from its lower part. These access closures are equipped with adjustable air inlet holes. The partial or total opening and closing, allows a certain control of the combustion by the contribution of more or less quantity of air, by the lower part of the fireplace (combustion chamber) or by its upper part. Both air / oxygen feeds combined can generate different behaviors in the form of combustion, excess or shortage of air, fumes, etc.

In the chamber a bonfire of solid fuels is formed with an irregular and disorderly structure that prevents a uniform and complete combustion. The problems are constant due to the variability of the system parameters and its unpredictable organization.

The flames tend to move towards the top in an anarchic and unstructured way. The chimney is the complementary part of the system because it conditions the air intake by making a natural suction normally called "draft". This phenomenon is produced by the identification of the suction with a mechanical ascension force, caused by the low density of the hot air, compared to the high density of the outside air at the place of discharge, normally colder. The atmospheric pressure has a decisive influence on the chimney draft. In the lower part, where temperatures are lower, unburned fuels accumulate. The upward air flow cools the area, and prevents the arrival of hot gases or flames, from the highest parts of the combustion chamber.

Smoke emissions from incomplete combustion and other quality defects in the combustion process represent one of the biggest problems in solids combustion. In rural areas they are not so important but, in suburban or urban areas, the problems are very serious due to the impact on air quality that the population demands. Suspended particles PM10 and PM2.5 abound in incomplete combustion systems, polluting the air in cities.

The constant accumulation of unburned products on the grill, due to the lack of a homogeneous structure, blocks the entry of air through its lower part. This effect produces a reduction or interruption of combustion, with fuel losses reflected in the increase of ashes and other residues, in addition to the unburned that the smoke particles generate.

Operation is difficult to control when it comes to fuels of heterogeneous and uneven shapes. The temperatures that are reached are reduced and the combustion requires constant attention with corrective maneuvers of the variables due to the problems presented and the anarchy of the system. Fumes appear as a result of incomplete combustion. In the case of a high cost, uniform and homogeneous fuel, this problem is reduced.

Solid fuels are of diverse origins and compositions as well as very abundant in our society. They are at relatively low prices and even with negative costs due to the need for their elimination. The problem of its process is based on the emissions of the gases resulting from its combustion. In many cases, combustion generates compounds that are harmful to the environmental health of citizens. Another problem is the generation of unburned waste, as in the case of some waste incineration plants which, by processing heterogeneous products, generate completely useless and problematic ashes for their management.

The problems of emissions into the atmosphere of fossil fuels reside in greenhouse gases such as CO2 and other types of products generated during combustion. Another factor is the possibility of depletion of natural deposits, formed in the past and impossible to recover. Our civilization should bequeath to the populations to come, an important part of the resources that are currently being exploited.

One of the most pressing needs that we have in our society is the processing of the waste generated by our civilization, either from the waste generated by consumer goods as well as waste obtained in the manufacturing processes of industrial products such as wood, cellulose, paper, carpentry, joinery, etc.

The waste can be treated by incineration in suitable burners that take advantage of the heat of combustion. For this, there is no better procedure than its preparation to be used in a burner such as the one described in this document.

With the aim of collaborating with our society and with the aim of correcting the exposed problem, achieving the elimination of deficiencies and improving both production and investment yields and maintenance costs, there is a system widely studied by patent applicants, called: SOLIDS BURNER, WITH HORIZONTAL FLAMES WITHOUT SMOKE AND SYSTEM FOR THE USE OF COMBUSTION HEAT, which is described below.

Explanation of the invention

The burner is a device that solves the great problem of combustion of solids of diverse origin that it is desired to eliminate or use and take advantage of energetically.

The fuels, for their use in the burner, must be selected and conditioned appropriately for what: 1) The granulometry will have a uniformity in its dimensions so that the feeding is carried out without blockages or formation of holes. 2) The PCI and the PCS, or Lower Calorific Power and the higher Calorific Power, will be between certain values. Variations in these values will generate irregular combustion. 3) The humidity will be another of the parameters to observe and control so that it oscillates between certain values.

The entire exterior surface of the burner will be protected by a steel sheet coating (1). Inside the burner, there will be three layers of insulating material: cellular glass foam (14) for temperatures of 200 ° C, refractory insulation at maximum temperatures of 900 ° C (13) and refractory insulation (12) for maximum temperatures of 1,400 ° C, which will form the combustion chamber (6). The residues will be introduced into the burner through the upper opening, normally closed by the closing lid (2). A storage is generated in the upper areas (3) and in the feed hopper (4).

The process is carried out in the combustion chamber or hearth (6), with the reaction of the stored fuel, falling from the sides of the retention device (5) towards the area of the support grid (7). The air that enters from the outside through the door (10) that allows access to the ashtray (8), will pass into the combustion chamber through the holes in the grill (7), to react with the fuel, generating a zone high temperatures (from 1,000 to 1,400 ° C) and remaining as a "dynamic cloud" in the shape of an ellipsoid equipped with an outlet for the flames through the duct (11). The angular shape of the retention device generates a displacement of the upper load, allowing the passage through the inclined upper lateral surfaces. This diversion towards the walls of the chamber, mixing the central part of the stockpile with the sides, generates a preparation for the fuel for entry into the reaction zone (6). The fall of the fuel joins the air that rises through the grate (7), originating the core of combustion flames of ellipsoidal shape, whose longitudinal axis is aligned with the flame outlet conduit, at very high temperatures, achieving a complete combustion and the elimination of the fumes generated by the unburned particles. The zone is kept static by the upward movement of the air and the shape of the retention device, linked to the position of the flame outlet duct.

This phenomenon has been widely studied and analyzed in burners with very high efficiencies.

By achieving very high temperatures, a total combustion of the fuel is produced, achieving a total lack of fumes and unburned particles. Non-combustible objects will not be gasified and will remain on the surface of the grill (7) from where they will be extracted through the opening of the register (9). Unburned waste of reduced dimensions will fall towards the ashtray (8) through the perforations in the grill (7).

On the other hand, by providing a heat exchanger at the outlet (11) with a sufficient path to preserve the temperature of the chamber, the elimination of possible emissions of dioxins, furans and other compounds is achieved, complying with the requirements of the Regulation on Industrial Emissions and Development of Law 16/2002 on the prevention and integrated control of pollution, which transposes the European Union Directives on waste combustion into Spanish legislation.

The combustion chamber will be insulated from the outside with three layers of insulation. The innermost one in contact with the combustion will be made of refractory mortar (12), which supports a temperature of 1,400 ° C, which is covered with another layer of refractory and insulating mortar (13), which supports a temperature of 900 ° C and To protect it, there is an insulating layer of cellular glass (14), prepared to withstand high temperatures up to 200 ° C and have insulating characteristics so that, on the outer surface of the burner, there is no appreciable loss of heat on contact. with room temperature.

The invented system comprises several fundamental parts that make up the burner assembly:

Sheet steel covering for external protection (1) - Fig. 1, 2, 3, 4, 5 and 6

Closing cover (2) - Fig. 1, 2, 3 and 4

Fuel storage and loading area (3) - Fig. 3 and 4

Fuel dosing hopper (4) - Fig. 3 and 4

Fuel retention device (5) - Fig. 3, 4, 7 and 8

Combustion chamber or hearth (6) - Fig. 3 and 4

Refractory perforated grill 1,400 ° C (7) - Fig. 3, 4, 5, 6, 7 and 8

Ashtray (8) - Fig. 3 and 4

Registration and cleaning cover (9) - Fig. 1, 2, 4, 5, 7 and 8

Air inlet regulation door (10) - Fig. 1, 2, 4, 7 and 8

Combustion flame outlet (11) - Fig. 2, 3, 4, 5, 6, 7 and 8

High temperature refractory insulation 1,400 ° C (12) - Fig. 3, 4, 5 and 6

SIAL 900 ° C temperature insulation (13) - Fig. 3, 4, 5 and 6

Room insulation foam glass 200 ° C (14) - Fig. 3, 4, 5 and 6

Description of the parts

- Sheet steel covering for external protection (1)

It is the outer coating of the entire burner, which will prevent the contact of the external agents with the foam insulation of insulating glass or cellular glass, at the same time that it will prevent the passage of the outside air towards the interior parts of the burner.

- Closing lid (2)

It is the device that allows the fuel to be fed, preventing the accidental entry of objects that could impair operation. At the same time, it prevents the entry of outside air so as not to impair storage and combustion chamber operations.

- Fuel storage and loading area (3)

It is the reception and storage area of the solids to be processed. It will be constantly maintained at a sufficient level to compact the stock and allow continuity in the processing.

- Fuel dosing hopper (4)

It is the area prior to the entry of fuels to the combustion zone, where a certain compaction will occur prior to entry into the combustion chamber due to the inclination of the walls. The residue increases the rate of descent and experiences an increase in temperature due to its proximity to the combustion chamber.

- Fuel retention device (5)

This element is key to the combustion process and the formation of the reaction zone at very high temperature. The angular shape displaces the solids towards the walls of the feed zone above the combustion chamber. It will consist of refractory material of 1,400 ° C.

- Combustion chamber or hearth (6)

It is the one delimited in its upper part by the retention device and the fuel that accumulates in the fuel inlet area on the combustion chamber, the air inlet grill through its lower part, the refractory side walls and the exhaust duct. output of the flames generated. The design generates an ellipsoid-shaped combustion confinement, with a horizontal major axis oriented towards the flame outlet duct.

- Refractory grid of separation 1,400 ° C (7)

It is located in the lower part of the combustion chamber and is provided with air inlet holes to feed the combustion reaction. Made up of refractory mortar to withstand the temperatures of the combustion generated.

- Ashtray (8)

It is located in the lower part of the burner and is enabled to receive non-combustible materials or ashes that may be generated over time of use, depending on the type of fuel.

- Manhole cover and cleaning (9)

It is a closing element of the combustion chamber, on the opposite side to the outlet of the flames. It will be used for the periodic cleaning of improper incombustible residues, the inspection of the chamber walls and the extraction of the grill for cleaning and replacement.

- Air inlet regulation door (10)

It is the device for accessing the burner from its lower part that incorporates an adjustable hatch to control the air inlet. The regulation will be automated to achieve the stability of the characteristics and parameters of the flames generated demanded by the desired process.

- Combustion flame outlet (11)

It is the outlet conduit for the flames generated in the combustion zone, which will communicate with the energy use exchanger. It will be built with the same refractory insulation as the interior walls of the burner. Its shape is prismatic tubular with a square section and a slightly inclined orientation, forming a slightly upward angle with the horizontal. It is key for the formation of the ellipsoid or cloud and the exit of the flames from the combustion zone.

- High temperature refractory insulation 1,400 ° C (12)

It is the internal lining of the combustion chamber and the outlet conduit for the flames generated by combustion. It is made up of a refractory material mortar that will withstand temperatures close to 1,400 ° C.

- SIAL 900 ° C temperature insulation (13)

It is the insulating wall that protects the internal lining of the combustion chamber and that of the outlet duct from the flames generated by combustion. It is made of refractory material mortar type SIAL, which will withstand temperatures close to 900 ° C.

- Room insulation foam glass (14)

It is the insulating wall that protects the SIAL lining in the outlet duct from the flames generated by combustion. It is made of cellular glass or resistant glass foam, which will withstand temperatures close to 200 ° C.

Brief description of the drawings

To better complement the description that is being made and in order to help a better understanding of the characteristics of the invention, it is attached as an integral part of said description, some drawings in which, with an illustrative and non-limiting nature, it has been represented the next:

Figure 1.- Front or Elevation View A-A '

You can see the view of the burner from the outside, with the details of the closing cover (2) of the fuel storage, the closing of the area where the combustion takes place (9) and the access door to the ashtray ( 10) where you can see the air feed inlet.

Figure 2.- Left side view or BB 'elevation

You can see the view of the burner from the outside, with the details of the fuel storage closure cover (2), the closure of the area where the combustion takes place (9), the access door to the ashtray in where the air supply inlet (10) and the burner flame outlet (11) can be seen.

Figure 3.- Section C-C 'through the left-right section

You can see the sectional view of the burner, with the details of the fuel storage cap (2), the upper storage area (3), the combustion chamber loading hopper (4), the cross section of the fuel retention device (5), the section of the combustion chamber (6), the air inlet grill (7), the ashtray for receiving the unburned residues (8), the flame outlet duct of the burner (11) and the layers of refractory insulation (12) and (13), the outer insulation (14) and the outer cladding steel sheet (1).

Figure 4.- Section D-D 'through the rear-front section

You can see the sectional view of the burner, with the details of the fuel storage closing cover (2), the upper storage area (3), the combustion chamber loading hopper (4), the longitudinal section of the fuel retention device (5), the section of the combustion chamber (6), the air inlet grill (7), the ashtray for receiving the unburned waste (8), the closure of the area where combustion develops (9), the access door to the ashtray where you can see the air supply inlet (10), the burner flame outlet duct (11) and the refractory insulation layers (12) and (13), the outer insulation (14) and the outer cladding steel sheet (1).

Figure 5.- Section E-E 'horizontal through the grill

You can see the sectional view of the burner, with the details of the air inlet grill (7), the closure of the area where the combustion takes place (9), the outlet duct of the burner flames (11) and the refractory insulation layers (12) and (13), the outer insulation (14) and the outer cladding steel sheet (1).

Figure 6.- Horizontal section F-F 'through the upper part of the grill

You can see the sectional view of the burner, with the details of the air inlet grill (7), the outlet of the burner flames (11) and the refractory insulation layers (12) and (13), the exterior insulation (14) and the outer cladding steel sheet (1).

Figure 7.- Upper right rear wired view

You can see the view of the burner, in wire form without hiding the lines with the details of the: retention device (5), the air inlet grill (7), the access register to the combustion chamber (9 ), the air inlet for combustion and ash outlet (10) and the outlet duct for the burner flames (11).

Figure 8.- Upper left front wired view

You can see the view of the burner, in wire form without hiding the lines with the details of the: retention device (5), the air inlet grill (7), the access to the combustion chamber (9), the air inlet for combustion and ash outlet (10) and the outlet duct for the burner flames (11).

Claims (1)

1. Solid burner, with horizontal flames without smoke and a system for the use of the heat of combustion, characterized in that it comprises: • an upper solid fuel storage tank (3) closed with a protective swing cover (2). • a hopper attached to the front tank (4) for the continuous supply of the solids to be burned with a compaction prior to the process due to the inclination of the sides. • a separation of the combustion zone and the ashtray formed by a perforated grill made of refractory material (7) that serves as a support for the non-combustible products. • a supply of air to the combustion zone through the perforated grill (7) made of refractory material for a temperature of 1,400 ° C. • an outlet conduit for the combustion flames (11), made of refractory material for a temperature of 1,400 ° C. Its shape is prismatic tubular with a square section and a slightly inclined orientation, forming a slightly upward angle with the horizontal. • an angular displacement and retention device (5) made of refractory material at 1,400 ° C with an inverted "V" shape. It is located on the combustion chamber, parallel to the plane of the grate with the longitudinal axis perpendicular to the face of the burner where the flame outlet conduit is located. The geometry and placement of the device (5), allows the ignition of the fuel with the feeding of atmospheric air from the lower entrance through the grill (7) and together with the phenomenon generated by the exit of the flames towards the hole (11), it collaborates to form a volume of combustion gases or cloud in the shape of an ellipsoid, with its main axis oriented perpendicularly towards the lateral face where the outlet of the flames is located and parallel to that of the retention device. Due to this configuration, in this volume high temperatures are generated that produce the instantaneous ignition of the gradual feeding of the solids and their total combustion without smoke. • complete insulation of the combustion chamber, based on refractory and insulating materials for working temperatures of 1,400 ° C for the inner refractory layer (12), 900 ° C for the intermediate refractory and insulating layer (13) and 200 ° C for external foam glass insulation (14). • an air inlet control system activated by a flap (10) to feed the combustion by means of a mechanical device for controlling the composition of the combustion gases or flames, to achieve complete combustion. • an access system to the combustion chamber (6) closed by the door (9) that allows the periodic elimination of non-combustible materials that are deposited on the grill due to the presence of inappropriate or inappropriate materials in the fuel.