EP3023722A1

EP3023722A1 - A transportable installation for drying wood chips

Info

Publication number: EP3023722A1
Application number: EP14382469.6A
Authority: EP
Inventors: Fernando Bausela Sánchez
Original assignee: Df Mompresa SAU
Current assignee: Df Mompresa SAU
Priority date: 2014-11-24
Filing date: 2014-11-24
Publication date: 2016-05-25

Abstract

A mobile chip drying installation, suitable for drying a mixture of wood chips, which uses the chips themselves as fuel for drying and which comprises a hot air generator, a trommel dryer, a fine particle separator system and a control system: the control system being linked simultaneously in data communication with the hot air generator, the trommel dryer and the auxiliary fine separator system, such that the hot air flowing out of the hot air generator circulates through the inside of the trommel dryer, in which they come into contact with the wood chips, thus removing humidity, in such a way that the flow of hot air coming out of the trommel dryer circulates through the auxiliary fine separator system.

Description

OBJECT OF THE INVENTION

The aim of the present invention is to register a mobile chip drying installation, which includes significant innovations and advantages in comparison to the techniques used to date.
More specifically, the invention proposes the development of a mobile chip drying installation, which, given its specific arrangement, makes it possible to dry wood chips known about, which are to be dried prior to being transported, in a more advantageous and effective way than in the technical solutions already known about.

BACKGROUND OF THE INVENTION

Different solutions that meet the need for wood chips to be dried before they are transported, thereby preventing the water they contain from being transported with them, are known about in the current state of the art.
However, the different technical solutions known about to date cannot be moved, therefore meaning the wood chips must be moved to the dryer. These are fixed installation that cannot be moved.
The present invention helps to resolve the present problem, since it makes it possible for the wood chips to be dried in the place where they are milled, thereby resolving all the aforementioned drawbacks.

DESCRIPTION OF THE INVENTION

The present invention was developed with the aim of providing a mobile chip drying installation, suitable for drying a mixture of wood chips, and is essentially characterised by the fact that it uses the chips themselves as fuel for drying, and in that it comprises a hot air generator, a trommel dryer, a fine particle separator system and a control system, the control system being linked simultaneously in communication data with the hot air generator, the trommel dryer and the auxiliary separator system, the hot air generator and the trommel dryer being linked and installed with one another, such that hot air coming out of the hot air generator circulates and flows through the inside of the trommel dryer; the trommel dryer and the fine particle separator system being linked and installed with one another, such that the flow of hot air coming out of the trommel dryer circulates through the auxiliary separator system; the trommel dryer being provided with input means for the chips to be dried and output means for the dry chips inside the same trommel dryer to come out of.
In a preferred embodiment, in the mobile chip drying installation, the hot air generator is inserted into a container.
In a preferred embodiment, in the mobile chip drying installation, the trommel dryer is inserted into a container.
In a preferred embodiment, in the mobile chip drying installation, the fine particle separator system is inserted into a container.
Preferably, in the mobile chip drying installation, the hot air generator comprises a fuel storage silo, fuel extraction means for extracting fuel from the silo, a biomass furnace and fuel transfer means, for transferring the fuel to the biomass furnace.
In addition, in the mobile chip drying installation, the biomass furnace comprises a grate.
Alternatively, in the mobile chip drying installation, the grate vibrates.
In addition, in the mobile chip drying installation, the trommel dryer comprises a tubular structure, which rotates around its own axial axis, with an input end, provided with input means through which to insert the chips to be dried and another output end, provided with output means for the dry chips to come out of.
In addition, in the mobile chip drying installation, the fine particle separator system, comprises a cyclone, an extractor and an extraction chimney.
In addition, in the mobile chip drying installation, the fuel extraction means for extracting fuel from the silo comprise a leaf spring extractor.
In addition, in the mobile chip drying installation, the fuel transfer means comprise a drive screw.
In addition, in the mobile chip drying installation, the input means comprise a conveyor belt.
In addition, in the mobile chip drying installation, the outlet means comprise an unloading belt.
An advantageous technical solution for drying wood chips is achieved as a result of the present invention, with the ability to be moved and easily transported, which is simple and quick to mount, with suitable environmentally friendly energy consumption and a low maintenance costs, given that an additional fuel source is not required, since it uses the wood chips themselves as fuel for drying.
Other characteristics and advantages of the mobile chip drying installation shall be made clear in the description of a preferred but not exclusive embodiment of the invention, illustrated by way of non-limiting example in the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1.- Is a schematic perspective view of a preferred embodiment of the mobile chip drying installation of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

As described in the object of the invention, the mobile chip drying installation of the present invention is designed for drying wood chips before they are transported.
As shown schematically in figure 1, the mobile chip drying installation comprises a hot air generator 1, a trommel dryer 2, a fine particle separator system 3 and a control system 4.
The control system 4 is linked in data communication and is able to simultaneously govern alongside the hot air generator 1, the trommel dryer 2 and the fine particle separator system 3, in order to thus be controlled by the user. Said control system receives and processes data from the hot air generator 1, the trommel dryer 2 and the fine particle separator system 3, and thus governs them in a suitable way, in order for them to undergo the drying process.
The hot air generator 1 is one of the fundamental parts of the installation, being responsible for supplying the energy needed to raise the temperature of the air subsequently introduced into the trommel dryer 2, in order to dry the wood chips.
In this preferred embodiment, the hot air generator 1 comprises a storage silo 11 for storing the fuel to be used (i.e. the dry wood chips themselves), a number of fuel extraction means for extracting fuel from the silo 11, a biomass furnace 12 and a number of fuel transfer means for transferring fuel to the biomass furnace 12.
In order to set the process into motion, the biomass furnace 12 of the hot air generator 1 must be activated.
In order to do so, fuel is fed into the biomass furnace 12 from the silo 11 itself, through the fuel extraction means 11 for extracting fuel from the silo 11. In this embodiment, the fuel extraction means for extracting fuel from the silo 11 comprise a leaf spring extractor 13, the fuel constituting dry wood chips.
The silo 11 has a built-in alarm, which is activated when the level of fuel stored inside the silo 11 itself falls below a predefined safety level. The operator is then warned that the silo 11 needs to be refilled with fuel, in order to prevent fuel that feeds the biomass furnace 12 from quickly running out.
Fuel is extracted from the silo 11 automatically, after being activated by the control system 4, on demand of the biomass furnace 12, via fuel extraction means for extracting fuel from the silo, which in this embodiment, comprise the spring leaf extractor 13.
The fuel is then introduced into the biomass furnace 12 via fuel transfer means for transferring fuel from the silo 11, which in this embodiment, comprise a drive screw 14, with a rotary valve that dispenses the fuel onto grates 121 in the biomass furnace 12.
The biomass furnace 12 is provided with combustion fans (not shown in the drawing), which inject air and enable the complete combustion with maximum use of the calorific value of the fuel. The special design with vibrating grate 121 technology ensures the fuel and combustion agent are better mixed and improves distribution in the combustion area, in order to increase the performance of the of the hot air generator 1 and increase the range of usable fuel conditions (enabling high performance even with fuels with humidities of up to 50%).
In other preferred embodiments, the grate 121 may be of other varieties or may not vibrate.
On the upper portion of the grate 121 of the biomass furnace 12, where the fuel is introduced, the humidity drying process inherent to combustion occurs. On the central portion of the grate 121, the combustion reaction occurs, reaching the adiabatic flame temperature that produces the greatest heat radiation emission. Furthermore, in the lower portion, as a culmination of the process, waste ash from complete combustion is produced.
The tiered grate 121 is equipped with vibrating sections, in order to achieve controlled distribution of the fuel. The speed at which the sections move is adjusted for each fuel from the control system 4 in order to achieve a process with optimal combustion. In turn, it facilitates better cleaning of the ashes along the entire surface of the biomass furnace 12, thus ensuring that the work area is always completely suitable.
The primary combustion air is supplied through a number of holes (not shown in the drawing) between the grate 121 in sub-areas differentiated according to the combustion stages described previously.
The secondary combustion air is supplied though a number of holes (not shown in the drawings) in the walls above the portion of the grate 121. Both the primary and secondary air are adjusted individually, in order to achieve optimal combustion.
The trommel dryer 2 is the component of the installation of the invention in which the wood chips are dried. It is made up of a tubular structure that rotates around its own axial axis. The hot air from the hot air generator 1 and the humid chips are simultaneously introduced at one end 21 (or wet product inlet) and the dry chips and used air are extracted from the other end 22 (the dry product outlet). The tubular structure of the trommel dryer 2 rotates around its own axial axis, turning the chips to be dried over, over the flow of hot air, in turn causing it to move forwards, in order to increase the contact between the wood chips and the hot air, thus facilitating the removal of humidity.
The trommel dryer 2 is of the rotating type designed to dry chips with an input humidity of 50%, through to an end output humidity of 20%.
The product to be dried, i.e. the wood chips, which are piled up close to the installation of the invention, is arranged and introduced via input means for the product to be dried at one of the ends 21 (the wet product inlet) of the trommel dryer 2. In this embodiment, the input means comprise a conveyor belt 23, which feeds into the trommel dryer 2. This conveyor belt 23 drives and introduces it into one of the ends 21 (the wet product inlet) of the trommel dryer 2 unit, through which the combustion gasses from the hot air generator 1 previously described enter simultaneously.
Both the hot gasses and the product to be dried are located in parallel currents, in such a way that the hot air for drying at higher temperatures (450 ºC-500 ºC) comes into contact with the colder, more humid product to be dried.
The product to be dried travels through the trommel dryer 2 by means of the rotational movement of the same and eliminates the amount of water required in the process. The interior design thereof means that the turning blades are constantly cutting through the product to be dried, thus preventing clumps from forming, which inhibit the drying action, in addition to enabling optimal performance.
The blade advance system, as well as the angle and fixing brackets, are designed to offer, alongside the revolutions and angle of the trommel dryer 2, the greatest drying performance of the product to be dried.
Once the product has attained the desired characteristics, it is extracted through the action of a number of outlet means for the now dry product to come out of. In this embodiment, the outlet means comprise a discharge conveyor 24.
The used air coming out of the trommel dryer 3 then passes through a fine particle separator system 3, in which the exhaust gasses are purified, by pouring the fine particles suspended therein, before being released into the atmosphere.
In this preferred embodiment, the fine particle separator system 3 comprises a cyclone 31, an extractor 32 and an extraction chimney 33.
The cyclon serves to purify and separate the solid particles from the air flow circulating at the outlet of the trommel dryer 2, in order to prevent them from being released to the outside through the chimney 33. In the cyclone 31, they are separated so that the dry product mixed with the outlet air of the trommel dryer 2 may be collected.
The extractor 32 is responsible for inducing the circulation of air at the outlet of the trommel dryer 2, in order to cross the cyclone 31 and release the air through the chimney 33.
The hot gasses are released into the atmosphere through the chimney 33.
The hot air generator 1 and the trommel dryer 2 are linked and installed with one another, such that the air from the hot air generator 1 and the wood chips inserted simultaneously into the trommel dryer 2 circulate and flow together through the trommel dryer 2.
The hot air from the hot air generator 1 is introduced through a duct in the trommel dryer 2. At the same time, the wood chips to be dried are inserted into the upper portion of the end 21 (or wet product inlet) of the trommel dryer 2 by means of the conveyor belt 23.
The hot air and the wood chips be dried immediately come into contact and are mixed inside the trommel dryer 2, therefore causing the water contained in the wood chips to evaporate, in turn reducing the humidity therein.
During this process, the hot air becomes more humid and colder in temperature.
The trommel dryer 2 continues to rotate and the wood chips move forwards until they exit through the end 22 (or dry product outlet) of the trommel dryer 2. The trommel dryer 2 releases the now dry wood chips using the discharge conveyor 24 in order to store the dry chips in piles 25.
At the same time, it also releases the hot air introduced, which comes from the hot air generator 1 and is used for drying the wood chips.
At the same time, the trommel dryer 2 and the fine particle sepataor system 3 are linked and installed with one another, such that the outlet flow of hot air coming out of the trommel dryer 2 passes and circulates through the fine particle separator system 3.
The fine particle separator system 3 separates any possible remaining dry wood chips found in the hot air out the outlet of the trommel dryer 2, so that they may also be used, preventing them from being released into the atmosphere.
The mobile chip drying installation of the present invention therefore provides considerable advantages over conventional systems already known about.
It is highly mobile and easy to move, it being possible to move it to the area where the wood chips are to be processed, with ease of transport, since its design enables the hot air generator 1, the trommel dryer 2 and the fine particle separator system 3, in addition to their auxiliary equipment, to be modularised inside standard measurement containers, as shown schematically in figure 1, thus facilitating the transport thereof.
In another preferred embodiment of the mobile chip drying installation of the invention, the fine particle separator system 3 may be inserted into a container whilst being transported and removed during the drying process.
It is simple and easy to mount, with a very short period of time between the equipment arriving until it is operated. The need for interconnection between the modules has been reduced to a minimum in order to make the mounting/dismounting tasks easier.
It reduces CO₂ emissions, since the heat needed to dry the wood chips is obtained from the combustion of the wood chips themselves in a biomass furnace 12, installed in one of the containers, in such a way that the majority of the energy for the drying process comes from renewable sources.
The ground does not require any kind of special preparation. It is sufficient for the ground to be flat and have a minimum resistance of 2 kg/cm².
The system is automatic, as it is fed by the biomass to be dried itself, it thus being able to work outdoors, with simple, cheap maintenance.
The details, shapes, dimensions, and other auxiliary elements, in addition to the materials used to manufacture the mobile chip drying installation of the invention, may be conveniently substituted by other, technically equivalent factors, which do not break away from the essence of the invention or from the scope defined by the claims included below.

Claims

A mobile chip drying installation, suitable for drying a mixture of wood chips, characterised in fact that it uses the chips themselves as fuel for drying, and in that it comprises a hot air generator (1), a trommel dryer (2), a fine particle separator system (3) and a control system (4), the control system being linked simultaneously in data communication with the hot air generator (1), the trommel dryer (2) and the auxiliary separator system (3); the hot air generator (1) and the trommel dryer (2) being linked and installed with one another, such that the hot air flowing out of the hot air generator (1) circulates and flows through the inside of the trommel dryer (2); the trommel dryer (2) and the fine particle separator system (3) being linked and installed with one another, such that the hot air flowing out of the trommel dryer (2) circulates through the auxiliary separator system (3); the trommel dryer (2) being provided with input means through which to introduce the chips to be dried, and output means through which the dry chips inside same trommel dryer (2) can come out of.
The mobile chip drying installation according to claim 1, characterised in that the hot air generator (1) is inserted into a container.
The mobile chip drying installation according to claim 1, characterised in that the trommel dryer (2) is inserted into a container.
The mobile chip drying installation according to claim 1, characterised in that the fine particle separator system (3) is inserted into a container.
The mobile chip drying installation according to claim 1, characterised in that the hot air generator (1) comprises a fuel storage silo (11), fuel extraction means for extracting fuel from the silo (11), a biomass furnace (12) and fuel transfer means, for transferring fuel to the biomass furnace (12).
The mobile chip drying installation according to claim 5, characterised in that the biomass oven (12) comprises a grate (121).
The mobile chip drying installation according to claim 6, characterised in that the grate (121) vibrates.
The mobile chip drying installation according to claim 1, characterised in that the trommel dryer (2) comprises a tubular structure that rotates around its own axial axis, with an input end (21) provided with input means, through which to introduce the chips to be dried, and another output end (22) provided with output means through which the dry chips can come out.
The mobile chip drying installation according to claim 1, characterised in that the fine particle separator system (3) comprises a cyclone (31), an extractor (32) and an extraction chimney (33).
The mobile chip drying installation according to claim 5, characterised in that the fuel extraction means for extracting fuel from the silo (11) comprise a spring leaf extractor (13).
The mobile chip drying installation according to claim 5, characterised in that the fuel transmission means comprise a drive screw (14).
The mobile chip drying installation according to claim 1, characterised in that the input means comprise a conveyor belt (23).
The mobile chip drying installation according to claim 1, characterised in that the outlet means comprise a discharge conveyor (24).