EP3121544A2 - Method and device for the treatment of organic fuels, in particular forest cutting chips - Google Patents

Abstract

When drying solid organic fuels, in particular forest wood chips, by drying the solid fuel in a drying device (4) by means of blown drying air, wherein the solid fuel is circulated during drying, so that the drying air flows through the solid fuel, according to the invention thereby the supply amount Solid fuel per unit time regulated so that either the exhaust air has a certain exhaust air target or from the drying device (4) emerging solid fuel has a residual moisture content of 13-15%.

Description

I. Field of application

The invention relates to a method and a device for processing organic solid fuels, including drying to defined water content and in particular fractionation of solid fuels. The solid fuels are, in particular, forest woodchips.

II. Technical background

Organic residues, especially from wood, can be used as a fuel.

For this purpose, so-called forest wood chips come into question. Forest wood chips are residues from the Derbholz-Schlägerung, ie the removal of branches and treetops in trees, or from the forest care and landscape management. In wood care, woodchips are produced primarily by the thinning of dense natural regeneration stands in which lack of light and food competition hinder the growth of the individual trunks. However, solid organic fuels, as relevant to the invention, can also be produced when working in sawmills or in general in industry.

One known form of use is to burn these organic solid fuels for heat generation. However, the problem is that the solid fuels have a relatively high water content. In forest wood chips, for example, the water content at the time of harvest is 50% on average for the year. This is mainly because it is freshly cut wood.

The storage of such solid fuels is problematic. In the forest or on the forest road piled up there is a danger that the harmful bark beetle nests therein and then spreads to the forest stock. A storage in the open field is only allowed within a development plan. Chopped, the wet material must be burned or processed after a few days, as it would otherwise rot due to the high water content. Currently, due to the rotting, there is a mass loss of about 5% per month in the summer.

An immediate recovery, ie an immediate combustion of solid fuels is possible and customary in cogeneration plants. With their requirement of more than 10,000 tons of wood per year, corresponding wood block heat and power plants can build a logistics organization with a very high turnover, tailored to their needs. However, things are different for municipal or operational heating plants. These usually have a wood consumption of less than 1000 t atro per year and therefore can not be supplied "just in time", ie immediately without time delay. So they have to be supplied from a warehouse that is already set up in the summer. In winter, the supply from the forest due to the snow is always endangered.

Another problem with the supply of smaller, ie municipal or operational heating plants is that in these the energy bound in the water vapor is lost because they have no capacitors for recovering the energy in the water vapor, in contrast to the larger wood cogeneration plants.

Since the wet chips must be stored in the meantime, unhealthy biological processes can arise in the stored wood chips, such as a Versporung. In addition, a biological drying takes place during storage. The composting heat evaporates part of the water with corresponding loss of dry matter. The water contents thus achieved vary between 20% and 40%, which however still means too high a water content for the efficient use of the heating plants.

To avoid these disadvantages, therefore, the solid fuels, i. the chips, dried by technical means.

For this purpose, the waste heat of cogeneration plants is mainly used, which is not needed, especially in summer for heating. The drying takes place - similar to the grain drying - in a batch process: the wood chips are poured 2-3 m high on a sieve, through which a dry air flows. After three or four days, the pile is completely dry. However, drying is inhomogeneous: the lower layers have a low water content of up to 0% , while the uppermost layers may have such a high water content that there is a risk of rotting. Further drying reduces the efficiency of the process.

Furthermore, plants are known which dry continuously and for this example have drums or sieve belts. By continuously moving the chips during drying, a resulting water content can be achieved with a lower variance of about 3 %.

However, these systems generally have the following disadvantages: Because of the small and fluctuating layer thickness of the dry material, part of the dry air is not saturated with water. Energy efficiency is affected. Furthermore, the moving parts of the system wear out quickly, the system therefore requires more frequent maintenance and the number of faults increases. Finally, the fines in the solid fuels, ie the wood chips lead to a sediment, ie a concentration in the transport containers and are therefore poured unmixed into the combustion boiler in the heating plant. The fines can thus increase the dust emission and possibly even extinguish the fire or cause a dust explosion. Therefore, it is attempted to remove the fines during or after the drying of the wood chips.

The WO 2010/094476 A2 proposes a dryer with a more efficient drying process that also allows wood chips to dry.

The dryer is a so-called Wälzbetttrockner having an elongated, horizontal container with an at least partially round cross-section. At one end of the container there is an inlet for the material to be dried and at the other end an outlet. The container has a double bottom, with the top bottom perforated so that dry air can flow through the perforation and through the material to be dried.

Furthermore, conveyors are provided which circulate the goods, in a direction transverse to the longitudinal extent of the container. The outlet has an overflow weir. In the container no conveyors are present, which actively transported the material to be dried from the inlet to the outlet. Instead, the goods are merely circulated and the transport takes place by itself, that over a certain filling level of the container, the good overflows the overflow weir at the outlet.

In the space of the double bottom, a screw conveyor is preferably arranged. The purpose of this is to remove heavy contaminants, such as sand or earth, that fall through the upper, perforated floor, which otherwise would have to be done periodically by hand.

In addition, it is provided in the dryer that light fines, such as dust, are transported with the exhaust air from the container upwards. Thus, in the dryer, the problem-causing dust is already removed during the drying process of the material to be dried.

a) Task

It is the object of the invention to provide a method and an apparatus for processing organic solids, in particular forest wood chips, by which or by which the above-mentioned problems are solved or at least reduced and the efficiency can be increased.

b) Solution of the task

This object is solved by the features of claims 1 and 10 . Advantageous embodiments will be apparent from the dependent claims.

• einerseits die Verrottung verhindert werden kann,
• andererseits der Energieaufwand für die Trocknung begrenzt wird,
• des Weiteren der Feinstaub-Anteil im Abgas bei Verbrennung der dieses Brennstoffs im Rahmen gehalten wird, da mit sinkendem Wassergehalt die Ablösung der Feinstaub-Partikel von dem Hackschnitzel vor dessen Verbrennung zunimmt..

The invention makes use of the knowledge that solid fuels, in particular wood chips and pellets from the common source material wood, with a water content of between 13 and 25% are preferable to those with a lower water content, for example from 5 to 10% at this water content of 13 to 25%

• on the one hand the rotting can be prevented
• on the other hand, the energy required for drying is limited,
• Furthermore, the proportion of particulate matter in the exhaust gas is kept in the context of combustion of this fuel in the context, since with decreasing water content, the separation of the particulate matter from the wood chips increases before combustion.

In the following, wood chips, in particular forest wood chips (WHS), are generally referred to as solid fuel. The im However, further described invention works with all conceivable solid fuels, especially those made of wood, as long as they can absorb water and thus may also have a water content.

According to the invention an apparatus and a method is proposed, wherein the chips are dried to the extent until they have a water content of 13-25%, preferably 13-19%, more preferably 14-17%, more preferably 14.5 to 15.5% and in the ideal Fall 15% . The abovementioned percentages are preferably percentages by weight.

With a corresponding drying, the equilibrium state of product and air in terms of the water content corresponding to the sorption can already be achieved in a limited residence time in the drying device according to the invention. This may be a residence time of about 30 to 45 minutes.

As a drying device, a dryer, hereinafter referred to as Wälzbetttrockner be used, as it is for example in the present WO 2010/094476 or has been described in the introduction to the description.

Above all, as mentioned, the fine dust values in the exhaust gas for fuels with the water content according to the invention are lower than for more dry fuels.

This is due to the fact that the escaping water can prevent an immediate escape of the fine dust and thus it can be burned, which additionally increases the efficiency.

In addition, the water content of the invention has the advantage that it is still too low for bacterial processes, whereby the wood does not decompose during storage and not faulty.

Furthermore, the invention proposes to use preferably for drying the medium air or fuel gases. In the case of woodchip drying by convection, the water absorption capacity of the drying medium air is of crucial importance.

During the flow through the chips, the air strives to reach a state of equilibrium between the water content and the air temperature, in particular according to the sorption isotherm.

The problem, however, is that in the case of the inventive use of a known Wälzbetttrockners without additional measures, the actual state of equilibrium between drying air and dried wood chips often can not be achieved because the Wälzbetttrockner is continuously and uncontrollably refilled with undried wood chips.

In a control of the process, there is also the problem that there are no promotion devices that transport the wood chips directly from the inlet to the outlet and thus the residence time of the chips can not be controlled directly.

However, it has been found that the statistical residence time of the WHS in the roller bed dryer, which should for example be 35-40 minutes, is already sufficient for the control to assume an equilibrium state (ie an equilibrium state can be assumed) and thus reliable calculations based on the assumption of such equilibrium condition can be made.

• Die dem Wälzbetttrockner zugeführte Wärmeleistung, d.h. die Temperatur und das Volumen und vorzugsweise auch die relative Luftfeuchtigkeit der zugeführten Trocknungsluft pro Zeit kann ermittelt und eingestellt werden. Wenn Letztere nicht ermittelt wird, wird vorzugsweise von einem Wert von 80 % ausgegangen. Weiterhin kann, insbesondere gemäß einem Leistungssenke-Modell, berechnet werden, wie viel Wasser durch diese zur Verfügung stehende Leistung abgeführt (d.h. verdampft) werden kann.

The control method according to the invention functions as follows:

• The heat output supplied to the roller bed dryer, ie the temperature and the volume and preferably also the relative humidity of the supplied drying air per time, can be determined and adjusted. If the latter is not determined, it is preferred that the value be 80 %. Furthermore, in particular according to a power sink model, it can be calculated how much water can be removed (ie evaporated) by this available power.

With regard to the chips, it can be determined which temperature and which moisture content they have at the inlet. Thus, based on the knowledge of how much energy (or rather how much power) is available through the drying air - can be calculated how much water can be dissipated by the drying air and thus how much chips can be dried per unit time the Wälzbetttrockner.

From this it can again be determined how high the throughput of woodchips may be, ie. How much wood chips can be fed per unit of time.

Since it is assumed that the supply of wood chips in the same way as the supply of drying air is essentially constant in time - except for a start-up phase - the time can be disregarded as a parameter in the calculation, so that the energy (in the Drying air and in the water to be evaporated) can be compared with each other, or an energy sink model can be used.

• die Temperatur der Abluft in einem vorgegebenen Ablufttemperatur-Zielbereich liegt und zusätzlich
  • 1A) der Wassergehalt der WHS, die die Trocknungsvorrichtung verlassen, in einem vorgegebenen Restwasser-Zielbereich liegt und/oder
  • 1B) die relative Luftfeuchtigkeit der Abluft in einem vorgegebenen Zielbereich liegt, dessen obere Grenze vorzugsweise knapp insbesondere um 2 - 5 %, unter 100 % liegt.

According to the invention, the supply amount of solid fuel, in particular WHS, per unit time in the drying device as the primary control variable is controlled so that

• the temperature of the exhaust air is in a predetermined exhaust air temperature target range and in addition
  • 1A) the water content of the WHS leaving the drying device is within a predetermined residual water target range and / or
  • 1 B) the relative humidity of the exhaust air is in a predetermined target range, the upper limit is preferably just in particular by 2 - 5 %, less than 100 %.

• Für die Zielgröße 1A) sollte der Wassergehalt der in die Trocknungsvorrichtung eingebrachten WHS entweder bekannt sein oder aktuell gemessen werden, da ja die Abnahme an Feuchtigkeit der WHS in der Trocknungsvorrichtung pro Zeiteinheit multipliziert mit der Durchsatzmenge die verdampfte Menge an Wasser pro Zeiteinheit ergibt, und dies mit der eingebrachten Wärmeleistung übereinstimmt.
• Für die Zielgröße 1B) muss vorzugsweise die relative Feuchtigkeit der Zuluft entweder bekannt sein oder aktuell gemessen werden, denn die Zunahme der relativen Feuchtigkeit multipliziert mit der Durchsatzmenge der Trocknungsluft entspricht ja der Wassermenge, die den WHS in der Trocknungsvorrichtung entzogen wurde.

For this purpose, the temperature of the supply air should be known or currently measured, since the difference between the temperature of the supply air and the exhaust air together with the amount per unit time represents the introduced and implemented in the drying device heat output.

• For the target size 1A) , the water content of the WHS introduced into the drying apparatus should either be known or actually measured, since the decrease in moisture of the WHS in the drying apparatus per unit time multiplied by the flow rate gives the evaporated amount of water per unit time coincides with the introduced heat output.
• For the target size 1B), it is preferable to either know the relative humidity of the supply air or to actually measure it, since the increase in the relative humidity multiplied by the flow rate of the drying air corresponds to the amount of water withdrawn from the WHS in the drying device.

Of course, the dwell time of the WHS in the drying apparatus is also determined by the feed rate, which experience has shown that the supply air temperature is about 70 degrees and the ambient humidity is about 30-50 weight percent and about 35 minutes to 40 minutes. The water content of the WHS should be 13 % to 19 %, in particular 14% to 16 °, when leaving the drying device.

Although the relative humidity of the exhaust air can be almost saturated, that is, the set point can be almost 100 %, but it should preferably be below 100 %, in particular between 80 % and 99 %, better 80 % to 90 %. Namely, at 100 % relative humidity, there is the danger that the exhaust air may not absorb all the moisture from the wood chips and thus the moisture not absorbed condenses on the woodchips emerging from the drying device.

100 % relative humidity of the exhaust air can therefore be regarded as an indication that the WHS have not been sufficiently dried.

If the controller for this primary controlled variable, namely the supply quantity to WHS, is not in their civilian area, the control device should generate fault messages.

The target range for the exhaust air temperature should be at 30 ° C to 50 ° C, better at 35 ° C to 40 ° C, in particular, it is assumed that a supply air temperature of 65 ° C to 75 ° C. If the temperature of the supply air is outside this range, the target range for the exhaust air temperature should be adjusted analogously, ie by the same temperature range.

The target range of the exhaust air temperature can be determined in particular taking into account the sorption isotherm, which in turn depends on parameters such as, in particular, the type of wood.

The supply air is often heated by a heat source whose temperature and / or power fluctuates per unit time, in particular of a heating fluid which heats the supply air before introduction into the drying apparatus in a heat exchanger.

• Zielgröße 2A ist die Zuluft-Temperatur, also die Temperatur der Trocknungsluft nach Erwärmen und vor dem Einbringen in die Trocknungsvorrichtung, insbesondere die Temperatur am Lufteinlass in die Trocknungsvorrichtung:
  • Diese Zuluft-Temperatur sollte knapp unterhalb der Vorlauf-Temperatur der Heizflüssigkeit, also kurz vor dem Wärmetauscher, liegen, vorzugsweise etwa 2° bis 5 °C darunter. Denn dann ist sichergestellt, dass die Luft fast die gesamte durch die Heizflüssigkeit angelieferte Wärmemenge von dieser übernommen hat. Indem die Zuluft-Temperatur unter der Vorlauftemperatur der Heizflüssigkeit gehalten wird, wird jedoch vermieden, dass der Heizflüssigkeit weniger Wärmemenge entnommen wird, als diese zur Verfügung stellt, was deshalb wichtig ist, da in aller Regel diese Heizflüssigkeit in einem Kühlkreislauf für ein zu kühlendes Aggregat, beispielsweise dem Gasmotor einer Biogasanlage, zirkuliert, welches ausreichend gekühlt werden muss.

The supply amount of drying air to this heat exchanger or to the heating heat source is controlled as a possible secondary control variable, for which in turn two different target sizes 2 A and / or 2 B are optionally available:

• Target size 2A is the supply air temperature, ie the temperature of the drying air after heating and before introduction into the drying device, in particular the temperature at the air inlet into the drying device:
  • This supply air temperature should be just below the flow temperature of the heating fluid, ie just before the heat exchanger, preferably about 2 ° to 5 ° C below. Because then it is ensured that the air has taken over almost all of the amount of heat delivered by the heating fluid from this. By keeping the supply air temperature below the flow temperature of the heating fluid, however, it is avoided that less heat is taken from the heating fluid than is available from the latter, which is therefore important, since as a rule this heating fluid is in a cooling circuit for a unit to be cooled , For example, the gas engine of a biogas plant, circulates, which must be sufficiently cooled.

Preferably, the supply air temperature is in a target range of between 60 ° C and 80 ° C, more preferably between 65 ° C and 75 ° C, since this has proven to be the optimum supply air temperature for the drying of WHS whose temperature is at Introducing into the drying device at about 20 ° C, in particular between 10 ° C and 30 ° C, and / or if the flow temperature of the heating liquid is about 80 ° C.

Target size 2B is the return temperature of the heat exchanger leaving the heating fluid: this should be below an upper limit of 67 ° C, better below 64 ° C, better below 62 ° C, especially if, as mentioned above, this heating fluid between the heat exchanger and the cooling system of Gas engine of a biogas plant circulates, as this is a sufficient cooling of the gas engine is offered.

• Zum einen entsteht beim in der Regel losen Transportieren und vor allem Einfüllen von staubbelasteten, getrockneten WHS in den Bunker einer Feuerungsanlage durch den Staubanteil eine hohe Staubbelastung in der Luft. Des Weiteren stellt ein Staubanteil in der Luft eine Gefahr dar, denn es kann dadurch zu Staubexplosionen in der Feuerungsanlage, in der die WHS verfeuert werden, kommen.

The forest wood chips should not only be dried efficiently to the right target size, but they should also be dedusted for several reasons:

• On the one hand, when dust is transported and, above all, that dust-laden, dried WHS is introduced into the bunker of a firing plant, it creates a high level of dust in the air due to the amount of dust. Furthermore, a dust content in the air is a danger, as it can lead to dust explosions in the firing system, in which the WHS are fired.

Furthermore, dust particles in transport containers, transport lines and the like form. Very quickly a strongly hardening sediment, which must be removed consuming, for example, to avoid blockages of piping or to determine the weight determination of the contents of containers properly.

• Für verkaufsfähige Waldhackschnitzel ist ein Zielbereich für die Partikelgröße vorgegeben, der den Gutanteil, der WHS darstellt.

For this purpose, the dried forest wood chips, which thus have left the drying device, fractionated into different sizes of the solid particles:

• For salable forest woodchips, a target area for the particle size is given, which represents the good part, the WHS.

The fractions with particle sizes below the size of the particle size of the material fraction, the so-called fine fraction and the dust fraction, are therefore separated from the dried solid fuel, ie separated from it.

These proportions - or preferably only the fine fraction - are agglomerated into larger particles, in particular pellets, in particular pressed, which have a size which is preferably within the permissible size range of the particles of the good fraction, and can then be added to the good fraction either again, since such Pellets are mechanically very resistant and do not raise the problems of the original fines or dust content, or be marketed separately for a variety of purposes.

Above all, the fine fraction often consists of particles which have a high resin content and thus a high calorific value compared to the rest of the WHS, above all the good content, so that the non-burning of just this fine fraction would noticeably reduce the heating output of the good fraction.

• Denn zum einen führt er bei dem Verpressen, welches beispielsweise durch eine Schneckenpresse erfolgen müsste, zu einem sehr schnellen Verschleiß und Zerstörung der Presse, insbesondere der Schneckenpresse, , die in keinem Verhältnis zu der zusätzlich erzielbaren Verkaufsmenge durch den Staubanteil steht.

Preferably, the dust content is not agglomerated into such larger solid units, but disposed of:

• For one thing, it leads to a very rapid wear and destruction of the press, in particular the screw press, in the pressing, which would be done for example by a screw press, which is out of all proportion to the additionally achievable sales volume by the dust content.

On the other hand, this dust content is often a considerable proportion of mineral, non-combustible, substances, so that this dust content for use as fuel is poor or not at all suitable, since it leaves a high proportion of slag in the combustion.

The dust content is preferably moistened during or immediately after sifting to reduce the dust load in the air in the screen, even during the subsequent removal of dust.

When the separation is done by sifting, the size of the particles of material content, fines content and dust content is defined by the hole size of the respective sieves or screening stages, which of course is freely selectable depending on the application purpose of the individual fractions and the requirements of the customers.

Preferably referred to as the dust content, if the particles have a maximum diameter of less than 3 mm, preferably less than 2 mm, preferably less than 1 mm, and thus the hole size, so the hole diameter of the finest sieve then owns this size.

The fines are preferably particles whose largest diameter is, for example, between 6 mm and 3 mm, so that the hole size of the second last sieve is then 6 mm.

The maximum size of the particles of the good portion should preferably be 40 mm, so that particles of a so-called coarse fraction, whose largest diameter is above this size, must also be deposited.

This is done by sieving by means of a sieve, over which the WHS are already passed before introduction into the drying device or which is angeordet as a third last sieve. Preferably, this coarse fraction will be further processed separately, for example mechanically comminuted and then returned to the fractionating device.

The exhaust air leaving the drying device also contains solid particles, preferably consisting of the dust content or sometimes also the fine fraction.

Since the exhaust air may contain only a certain proportion of solid particles when it is released into the environment, the solid particles are removed from the exhaust air by a gravity separator, preferably a cyclone.

The particular by gravity separation of the exhaust air removed solid particles are fed back to the fractionating, but preferably not at the stage on which the coarse fraction is already separated from the Gutanteil, but at the earliest on the stage at which the Gutanteil on the sieve to screen out Fine fraction is passed.

Preferably, these solid particles are even only one stage below the fine fraction supplied, from which then the dust content is filtered out.

This saves additional effort by again sifting out the supplied small particles from the much larger particles of the good portion.

• als primäre Regelgröße die Zufuhrmenge an WHS gesteuert wird durch Einhaltung einer oder beider Zielgrößen 1A oder 1B, und die Steuerung optimiert werden kann, indem zusätzlich
• als sekundäre Regelgröße die Zufuhrmenge an Trocknungsluft gesteuert wird durch Einhaltung einer oder beider dabei relevanten Zielgrößen 2A oder 2B.

The inventive method can therefore be controlled by

• As a primary control variable, the delivery rate to WHS is controlled by maintaining one or both of the 1 A or 1 B target sizes, and the control can be optimized by adding
• as a secondary control variable, the supply amount of drying air is controlled by observing one or both of the relevant target quantities 2 A or 2 B.

• eine Zuluft-Aufbereitungsvorrichtung zum insbesondere Erwärmen der Zuluft,
• eine Abluft-Aufbereitungsvorrichtung zum Abtrennen der Feststoffanteile von der Abluft aufweist sowie
• eine Feststoff-Aufbereitungsvorrichtung zum Bearbeiten, insbesondere Fraktionieren, nach Größe der getrockneten, die Trocknungsvorrichtung verlassenden, WHS.

For carrying out the method described, an overall device is preferably used which, in addition to the drying device operated by means of drying air

• a supply air conditioning device for heating in particular the supply air,
• an exhaust air treatment device for separating the solids from the exhaust air and has
• a solids treatment device for processing, in particular fractionating, according to the size of the dried, leaving the drying device, WHS.

In this case, the drying device has a drying chamber, which has in its lower region, in particular in the lower region of its side wall, an air inlet for drying air (supply air) and in its upper region, in particular in its upper side, an air outlet for the drying air (exhaust air).

In the lower region of the drying chamber, there is preferably an intermediate bottom with holes on which the WHS to be dried rest, so that the drying air flowing from below into the drying chamber can also flow through these holes upwards into the WHS resting thereon. The holes have a diameter which is less than the lower limit for the particle size of the salable good portion of the WHS, and in particular between 3 mm and 6 mm.

The solid particles already falling downwards through these holes in the drying chamber are correspondingly small, but above all also correspondingly heavy, in order to be able to approach the bottom, ie the intermediate plate, very rapidly within the fill from WHS, so that they are mostly mineral Ingredients like sand, earth or small stones are traded.

In the drying chamber could be a rotating about a preferably approximately horizontal axis drying drum instead of the intermediate plate, in which case the holes are distributed in the drying drum over the entire circumference.

Preferably, however, the drying chamber is a stationary chamber in which a rolling device circulates the WHS, so that they are dried uniformly and at the same time heavy components move due to the rolling down in the direction of the holes and fall through them through the intermediate plate and can be disposed of.

Therefore, in the bottom of the drying chamber, there is preferably a waste opening to which the floor is preferably inclined, while the air inlet for the supply air is in the lower space below the perforated intermediate floor, but in its side wall.

The arrangement of the air inlet and in particular the air duct in this lower space are preferably designed, for example, by air baffles are used, that the supply air flows evenly distributed through the intermediate plate into the overlying WHS.

The rolling device preferably consists of a shaft, which is rotationally driven by a motor and lies approximately horizontally, protruding from the agitator arms, which dip into the WHS, which lie on the intermediate bottom, and circulate the same.

The stirring arms are preferably designed in the form of paddles, and distributed over the circumference at least two, better three positions present and arranged in the axial direction of the shaft with the shortest possible distances, so as to ensure that all forest wood chips located in the drying chamber are also circulated. The successive in the axial direction of the shaft stirring arms or paddles are preferably offset from one to the next axial position in the circumferential direction in each case to each other.

Accordingly, at least the intermediate plate, preferably the entire drying chamber in the axial direction, the direction of the Shaft, considered, an inner circumference corresponding to a circular arc segment or an entire circular arc, which is located very close to the circle of the stirring arms or paddle, so that between the Rührarmen or paddles and especially the perforated intermediate bottom no larger particles, especially not the Gutanteils lie can.

This drying chamber has on its upper side at one axial end a material inlet, via which WHS can be filled and which is preferably hermetically sealed in order to produce a desired pressure level in the interior of the drying chamber.

The material outlet is at the axially opposite end of the drying chamber, preferably in an overflow weir, above which the opening of the material outlet is located, so that, like the water from the material inlet through the recirculation, the WHS at the other end leveling out at the level in the drying chamber Overflow weir fall out of the drying chamber as soon as a correspondingly large volume of WHS is present in the drying chamber.

The material outlet can also be hermetically sealed via a lock.

The WHS falling out of the material outlet of the drying chamber are fractionated in a downstream solids treatment device with regard to their particle size, preferably by means of a multi-stage screening plant.

Preferably, the sieves are slightly inclined from the location of the material application of forest wood chips to the lying on the respective sieve, not fallen through the openings, particles at the opposite, deeper lying end.

Preferably, the sieves are designed as Rüttelsiebe, so are oscillating in their plane or even transversely driven.

The WHS falling out of the material outlet of the drying drum preferably fall directly or by means of an inclined downwardly directed chute onto the uppermost sieve of the sieves arranged one above the other.

The uppermost sieve - which can be arranged upstream of the drying device instead of at this point - should as a rule separate particles which are larger than the permissible range of the particle size for the salable portion of WHS. The hole size of this screen is, for example, at 40 mm, and the coarse fraction of particles that does not fall through this top sieve, thereby not only separated from the rest, but preferably further processed by these large particles of the coarse fraction preferably by a crushing device, the may also be part of the overall device, crushed and placed again on the top level sieve.

The next from above, usually second, sieve of the sieves arranged below each other has a hole size of, for example, 6 mm, which is the lower limit for the particles of the salable part of WHS salable. On this sieve, the largest proportion, the good portion, of the WHS charged to the treatment device will remain and be either filled in the container or transported by means of a removal device to larger bunkers.

The next, usually third, sieve underneath has a hole size of, for example, 3 mm. The particles remaining thereon are referred to as fine fraction and are fed at the exit of this sieve to an agglomeration device, for example a press such as a screw press. From this, in particular larger particles are agglomerated, in particular pressed, whose particle size is in particular in the permissible size range of the particles of the material fraction.

These agglomerated larger particles, for example pellets, are then sold separately or added to a mixer, which mixes them with the particles of the screened crop, as they are sold together with the crop.

The dust particles penetrating the last-mentioned sieve fall on a collecting surface, wherein, in particular below the sieve, a moistening device is arranged in order to moisten the particles falling through the sieve and to prevent their floating in the air.

In the exhaust air treatment device, the exhaust air leaving the drying chamber is cleaned of solid particles.

For this purpose, the exhaust air via a corresponding pipeline to a gravity separator, preferably a cyclone fed by the solid particles are moved down, while the then cleaned of solid particles exhaust air can leave up into a fireplace or directly into the environment.

The solid particles deposited in the gravity separator are fed to the solids treatment device by a corresponding tube leading from the gravity separator, which is preferably located above the solids treatment device, to either the second-highest or the third-highest sieve level and, on the corresponding sieve, the most separated from the gravity separator small, applying particles on the application side of the corresponding screen for material.

The overall apparatus also includes a supply air conditioning apparatus in which ambient air is heated to serve as drying air.

The supply air is passed through a heat exchanger, which is flowed through by a heating fluid, which is preferably circulated between a heat source and the heat exchanger. A fan, which is preferably located downstream of the heat exchanger but upstream of the drying chamber, delivers the supply air through the heat exchanger and into the drying chamber.

The overall apparatus further includes, of course, an electronic control unit for controlling the overall apparatus, in particular according to one of the method claims.

The control unit controls the individual movable elements of the overall device, in particular the fan for the supply air, the motor for rotating the rolling device, optionally a supply device for WHS in the drying chamber, and possibly also the Rüttelantrieb the screens of the material processing device and the engine, which drives the screw press for pressing the fine fraction.

The control unit controls these movable elements based on data obtained from various sensors disposed within the overall device and forming part of the control unit.

These are preferably sensors which can measure both the water content of the WHS or the relative humidity of the drying air, or both.

A sensor for the water content of the WHS is preferably located close to the material inlet and / or a humidity sensor close to the material outlet of the drying chamber.

Likewise, a humidity sensor sits in the supply line for the supply air and / or in the exhaust duct or near the exhaust duct, these sensors also can be arranged within the drying chamber close to the air inlet or the air outlet.

Furthermore, temperature sensors may be present on the heating fluid pipeline for heating the supply air, in particular downstream of the heat exchanger, and / or also upstream of the heat exchanger.

Other temperature sensors can measure both the temperature of the air and / or the exhaust air and / or the WHS leaving the drying device.

Furthermore, the size of the hole in the intermediate floor can also be changeable and can be changed via a control element that can be activated by the control unit.

The control unit then preferably comprises a sensor which determines the quantity of particles falling through the holes of the false bottom per unit of time, be it the weight per unit time or the volume of this waste per unit time.

c) Embodiments:

Fig.1a:

eine schematische Darstellung einer erfindungsgemäßen Aufbereitungsvorrichtung von Waldhackschnitzel, und

Fig. 1b:

eine Querschnittansicht der Trocknungsvorrichtung aus Fig. 1 a.

An embodiment according to the invention is described below by way of example. Show

Fig. 1 a:

a schematic representation of a processing device according to the invention of forest wood chips, and

Fig 1 b.:

a cross-sectional view of the drying device Fig. 1 a.

• eine Trocknungsvorrichtung 4 zum Trocknen des organischen Festbrennstoffes mittels Trocknungsluft 60,
• eine Feststoff-Aufbereitungsvorrichtung 31 zum Aufbereiten des getrockneten Festbrennstoffes,
• eine Zuluft-Aufbereitungsvorrichtung 41 zum Aufbereiten der Trocknungsluft,
• eine Abluft-Aufbereitungsvorrichtung 21 zum Aufbereiten der Abluft aus der Trocknungsvorrichtung 4.

As FIG. 1 a, the overall apparatus 1 for processing organic solid fuels, in this case forest wood chips 50,

• a drying device 4 for drying the organic solid fuel by means of drying air 60,
• a solid processing device 31 for processing the dried solid fuel,
• a supply air conditioning device 41 for conditioning the drying air,
• an exhaust air treatment device 21 for processing the exhaust air from the drying device 4.

In addition, it has a central control unit 20 that the entire system, that is, the overall device 1 controls and is connected to all sensors and actuators, in particular all the electronic and electrical units, the overall device. 1

The drying device 4 is designed as a roller bed dryer 22 . The drying device 4 comprises a drying chamber 3, in which the woodchips are circulated and dried. The wood chips are a material inlet 14, in particular from above, fed into the drying chamber 3 and exit through a preferably arranged at the other end of the drying chamber 3 material outlet 15 back out from the drying chamber. 3

A circulation of forest wood chips in the chamber takes place by the rolling device 7. This has a rotatably mounted and driven by a motor shaft which extends along the longitudinal direction, the axial direction, the drying chamber 3, preferably centrally, in this and is arranged so in that the stirring arms projecting transversely from the shaft 7 , preferably in the form of paddles 8, can circulate all forest woodchips located in the chamber 3 . The rotational speed is variably adjustable and is predetermined by the control unit 20 and / or can be adjusted manually.

Thus, the "flow" of forest woodchips from the material inlet 14 to the material outlet 15 is possible, the drying chamber 3 and thus also the shaft of the rolling device 7 is as horizontal as possible.

As in particular in the axial view of the Fig. 1b can be seen, the drying chamber 3 a at least in the lower half circular arc, preferably a total of a completely circular cross-section.

As a result, it is possible for the paddles 8 rotating about the shaft 7 to grasp each region of the drying chamber 3 on the circumference, but at least in the lower half of the drying chamber 3. The paddles 8 are angularly offset from one another on the shaft 7 , for example with a 180 ° offset. and arranged axially so close to each other that they can detect as much as possible each area of the drying chamber 3 in the axial direction.

The drying chamber 3 has an intermediate bottom 23 with holes 19 , so that below the intermediate bottom 23 in the drying chamber 3, a lower space 9 results.

Through these holes 19 fall correspondingly small and heavy particles, usually the mineral components of uncleaned forest wood chips such as earth, stones and are disposed of via the waste opening 10 which is airtight sealable via a closure element 10a to set a desired air pressure within the drying chamber 3 to be able to.

In this lower space 9 drying air 60 (supply air) is blown through an air inlet 16 by means of a blower 2 , so that they are distributed in the lower space 9 and over the entire surface of the false floor 23 through the holes 19 upwards and through the forest wood chips stored thereon 50 flows and enriched with moisture leaving the drying chamber 3 through the air outlet 17 as exhaust again.

Preferably, the air inlet 16 is located in a side wall of the lower space 9, at the bottom of which the waste opening 10 is located.

During which the introduced via the material inlet 14 Wood chips 50 through the drying chamber 3 in the axial direction by the leveled at the location of the material inlet 14 first forming pile of wood chips by the agitation of the rolling device 7 and adjust a horizontal level of the top of the wood chips 50, which rises up to the height of the material inlet 14 opposite, formed at the front end of the drying chamber 3 , upright overflow weir 11.

As soon as this level is exceeded, forest wood chips fall out of the drying chamber via the upper edge of the overflow weir 11 and the material outlet 15 thus formed.

In order to check whether the wood chips 50 leaving the drying chamber 3 have the desired moisture content, their moisture can be determined directly by means of a moisture sensor 18b which is located close to the material outlet 15, preferably on the inside of the overflow weir 11 near its upper edge.

Alternatively or additionally, by means of a humidity sensor 18a in the exhaust duct 12, which adjoins the air outlet 17 , or even at or close to the air outlet 17 still in the drying chamber 3, the relative humidity of the exhaust air 60 are measured, and also via a temperature Sensor 18e whose temperature.

Depending on these values, by means of the control unit 20, on the one hand, the amount of quantity entered via the material inlet 14 , that is to say mass, can Waldhackschnitzeln 15, per unit time and / or the amount of injected into the drying chamber 3 drying air 60 are controlled.

The supply air to the drying chamber 3 is heated and usually has a temperature around 70 ° C, wherein the temperature of the supply air via a temperature sensor 18c can be measured.

The supply air is heated by means of a supply air treatment device 41 by air in a heat exchanger 25 is flowed through, on the other hand by a heating fluid which circulates in a fluid circuit 24 and just partially through the heat exchanger 25 and there the air in contact with the pipes the liquid circuit 24 device.

The temperature sensor 18 c is located downstream of the heat exchanger 25, ie between the heat exchanger 25 and the air inlet 16 of the drying chamber 4 or in the air inlet 16.

In addition, the temperature of the heating fluid in the fluid circuit 24 immediately downstream of the heat exchanger 25 is determined by another temperature sensor 18 , which is also reported to the control unit 20 , so that the blower 2 in terms of its performance, in particular its speed can be controlled so that in Depending on the temperature of the heating fluid, the supply air to the drying device 4 always has the same temperature.

The wood chips 50 emerging from the material outlet 15 of the drying device 4 are separated into different fractions with respect to the size of the particles in a downstream solid processing device 31 by means of a plurality of successive chaff chips 15 in succession, in particular sieving stages 26 a , b, c arranged one below the other.

The corresponding sieves 26 a, b, c are arranged directly below each other, and thereby the top sieve 26 a with the largest hole diameter with its material feed side directly below the material outlet 15, so that the wood chips emerging therefrom 50 fall directly on this top sieve 26 a , Of course, between the material outlet 15 and the top wire 26 a, a distance layer, but any type of conveyor for the wood chips from the material outlet 15 for the top 26 a sieve is then necessary, at least one obliquely downward slide.

On the top sieve 26 a remain - by appropriate choice of the hole size - only those particles are that are too large for the salable portion 50 b of forest wood chips 50 . This coarse fraction 50 a is disposed of, for example by, as shown here, at the lower end of the inclined sloping screen 26 a corresponding auger or other removal device is present.

The sieves 26 a, b, c are preferably all disposed obliquely sloping, so that the high side represents the material application side, and may be stationary screens or oscillating driven vibrating screens, so that at the lower free end of each sieve of the remaining portion in one Container falls down or otherwise disposed of.

The second sieve 26 b located below the first sieve 26 a has such a hole size that the proportion of forest wood chips remaining thereon represents the good fraction 50 b, which therefore has the desired particle size, which is guaranteed to the customer for the final product sold and in which Firing systems is manageable.

The passing through this second sieve 26 b particles are the fines 50 c, which no longer meets this criterion, but should still be recycled.

Therefore, this fines 50c at the outlet end of the screen 26 c an agglomeration device 6, here in the form of a screw press, supplied in the fine fraction 50 c is pressed into a strand which is cut into sections of a defined length, so that the resulting pellets 50 c 'also corresponds to the size specification of the salable good portion. Thus, the pellets 50 c 'thus produced can be mixed with the remaining on the second sieve 26 b Good portion 50 b and sold with.

The particles passing through this third sieve 26 c form the dust portion 50 d, which is not sold but is collected and disposed of in a container 13 or otherwise.

In order to minimize the dust load in the solid processing device 31 , the falling through this last sieve 26 c on a collecting surface dust content 50 d is moistened to avoid floating of this dust content 50 d in the ambient air.

This dust content 50 d can be used for other purposes, be it for compost production or for use in a biogas plant, from the waste heat preferably from the heating liquid comes, which heats the supply air 60 in the heat exchanger 25 .

The exhaust air 60 leaving via the air outlet 17 of the drying device 4 is fed via an exhaust air duct 12 to an exhaust air treatment device 21 in order to separate the solid particles contained in the exhaust air 60 from the exhaust air before it is discharged into the environment.

The exhaust air treatment device 21 is here a cyclone 5, via the upper air outlet 5a, the purified exhaust air 60 dissipated, in particular to the environment, while the opposite of the exhaust air 60 heavy Solid particles in the cyclone 5 sink down and leave the cyclone 5 via the lower outlet 5 b.

The cyclone 5 is positioned higher than the solids treatment device 31, so that the particles leaving the lower outlet 5 b of the cyclone, usually in terms of their size of the fines 50 c and the dust component 50 d belonging by gravity to be screened, dried forest wood chips 50 are fed back, but preferably not be placed on the top sieve 26 a, but on the sieve 26 b, on which the good portion 50 b should remain or even - preferably - on the third sieve 26 c, on which the fines 50th c should remain lying.

As a result, the large fractions of forest woodchips are no longer additionally burdened with fines and dust fractions to be separated.

LIST OF REFERENCE NUMBERS

1

total device

2

fan

3

drying chamber

4

drying device

5

cyclone

5 a

air outlet

5 b

lower outlet

6

agglomerating means

7

rolling device

8th

paddle

9

lower room

10

waste opening

10a

closure element

11

Overflow weir

12

exhaust duct

13

container

14

material inlet

15

material outlet

16

air intake

17

air outlet

18 a, b, c

sensor

19

hole

20

control unit

21

Air-conditioning device

22

Wälzbetttrockner

23

false floor

24

Liquid circulation

25

heat exchangers

26 a- c

Screening stage, sieve

27

conveyor belt

28

engine

29 30 31

Solid-treatment device

41

Supply air-conditioning device

50

Solid fuel, WHS

50 a

coarse fraction

50 b

Gutanteil

50 c, c '

fines

50 d

dust content

60

Drying air, supply air, exhaust air

Claims (20)

Process for continuous processing of solid organic fuels (50) containing a proportion of dust (50 d ) , in particular woodchips (50), by drying to a defined target water content and dedusting, comprising the following steps: continuous feeding of solid fuel (50) into a drying device (4), Drying the solid fuel (50) in the drying device (4) by blowing in drying air (60) which flows through the solid fuel (50) , wherein the solid fuel (50) is circulated during drying, Separating at least part of the dust portion (50 d) from the remaining solid fuel (50), Discharging the dried solid fuel (50) from the drying device (4), characterized in that - As a primary controlled variable, the supply amount of solid fuel (50) per unit time in the drying device (4) is controlled so that as a target size - The temperature of the drying device (4) leaving the drying air (60) (exhaust air) is in a predetermined exhaust air temperature target range, and in addition - The, in particular automatically, measured water content of the drying device (4) leaving solid fuel (50) is in a predetermined residual water target area and / or - The relative humidity of the discharged drying air (60) (exhaust air) is in an exhaust air humidity target range of 70-90 %. Method according to claim 1,
characterized in that
the residual moisture target range is 13-19 % by weight, more preferably 14-18 % by weight, more preferably 15-16 % by weight
and or
the exhaust air temperature target range 30 ° to 50 ° C, better 35 ° to 40 ° C, is, in particular at a supply air temperature of 65 ° to 75 ° C, and in particular the exhaust air temperature target range is set depending on the present supply air temperature , Method according to one of the preceding claims,
characterized in that
the supplied drying air (60) (supply air) is heated by a liquid circuit (24) with fluctuating temperature and / or fluctuating heating fluid throughput per unit time in a heat exchanger (25) and the supply amount per unit time of drying air (60) to the heat exchanger ( 25) is controlled as a secondary controlled variable so that - The supply air temperature of the introduced into the drying device (4) drying air (60) (supply air) is in a supply air temperature target range, the scarce, in particular 2 ° to 5 ° C, below the flow temperature of the heating fluid before the heat exchanger (25 ) is located and or - The return temperature of the heat exchanger (25) leaving liquid is below a return temperature upper limit, the 67 ° C, better only 64 ° C, better only 62 ° C, is. Method according to one of the preceding claims,
characterized in that
the drying device is operated with negative pressure to minimize the leakage of fine dust
and or
the relative humidity of the discharged drying air (60) (air) in an exhaust humidity target range 80-90% by weight.
(Dedusting + fractionating) Method according to one of the preceding claims,
characterized in that
in the dried solid fuel (50) contained fines (50 c ) and dust content (50 d ) are extracted and the fine fraction (50 c ) is agglomerated into larger solid units, in particular into pellets (50 c ' ) , in particular pressed, - The dust content (50 d ) is disposed of and or
the coarse fraction in the solid fuel (50) given (50 a) is extracted from the remaining Gutanteil (50 b) Method according to one of the preceding claims,
characterized in that
consisting of the fine fraction (50 c) agglomerated solid units (50 c ') with the Gutanteil (50 b) of the dried solid fuel (50) are brought together and mixed in particular.
and or Method according to one of the preceding claims,
characterized in that
the dust content ( 50 d) is moistened during extraction. Method according to one of the preceding claims,
characterized in that
the solid fuel (50 ) leaving the drying device (4) is screened for extracting fines ( 50 c) and dust ( 50 d) at least in two, better three, screening stages ( 26 ac), of which - The last screening stage ( 26 c) only the dust portion ( 50 d) fall through and in particular a hole size of 3 mm in the sieve ( 26 c), - the penultimate screening stage ( 26 b) screens out the fine fraction ( 50 c) and in particular has a hole size of 6 mm in the sieve ( 26 b), - the optional third last screening stage (26 a) the terms of the size salable solid fuel (Gutanteil) winkles and particularly to a hole size of 40 mm having in the sieve, and - Is separated by the screening stage ( 26 a) not falling coarse portion ( 50 a). Method according to one of the preceding claims,
characterized in that
the fine fraction ( 50 b) and dust fraction ( 50 c) contained in the exhaust air ( 60 ) are extracted therefrom, in particular by means of a cyclone (27), and the solid fuel (50) leaving the drying apparatus ( 4 ) at the latest before the penultimate screening stage ( 26 b) is returned, in particular before the first screening stage ( 26 a). Overall device (1) for the continuous processing of organic solid fuels, in particular forest wood chips, comprising: - A drying device (4) with a drying chamber (3), which comprises a circulating device, in which the solid fuel (50) of drying air (60) is flowed through, - An exhaust air treatment device (21), are separated in the solid components of the exhaust air - a solids treatment device (31) downstream of the drying device (4), in which the dried solid fuel (50) is fractionated and treated in terms of the size of its particles. Overall device (1) according to one of the preceding device claims,
characterized in that
the drying chamber (3) in its lower region, in particular in the lower region of its side wall, an air inlet (16) and in its upper region, in particular in its upper side, an air outlet (17) for the drying air (60) and in its lower Area an intermediate bottom (23) with holes (19) on which rests the solid fuel to be dried (50) , so that the drying air (60) through the holes (19) can flow up into the solid fuel (50)
and or
the drying chamber (3) is a stationary chamber in which a rotating rolling device (7) is arranged with paddles (8) projecting from the axis of rotation, which circulates the solid fuel (50) in the drying chamber (3) , and in particular a roller bed dryer ( 22) with a horizontal axis rotating Wälzvorrichtung (7) and the intermediate bottom ( 23 ) viewed in the axial direction of the rolling device (7) has an upwardly concave curvature corresponding to the circle of the paddle (8). Overall device (1) according to one of the preceding device claims,
characterized in that
the drying device (4) is a drum dryer and the drying chamber (3) is a drying drum rotating around a horizontal axis with holes (19) rotating in a surrounding housing through which the drying air (60) is passed and / or
the stationary drying chamber (3) or the housing surrounding the drying drum of the drum dryer at the bottom of a waste opening (10) through which fallen through the openings (19) fallen material can be removed. Overall device (1) according to one of the preceding device claims,
characterized in that
the drying chamber (3) has a material outlet (15) whose lower edge is formed by an upright overflow weir (11) for the solid fuel (50) and a material inlet (14) at a point as far as possible from the drying chamber (3) in the thereof upper area is present
and or
the air outlet (17) for the drying air ( 60) is located near the material outlet ( 15) in the upper region of the drying chamber (4) .
(Solid-treatment device) Overall device (1) according to one of the preceding device claims,
characterized in that
the solids processing device (31) comprises at least two, preferably three, screening stages ( 26 a, b, c) with corresponding screens ( 26 a, b, c), which are in particular arranged one below the other and the material outlet (15) leaving solid fuel (50) is fed via a feed device of the solids treatment device (31) , and in particular the uppermost screen level ( 26 a) of the solids treatment device (31) below the material outlet (15) of the drying device (4)
and or
the lowest, finest screening stage ( 26 c) lets through only the dust component ( 50 d) of the solid fuel (50) and in particular has a maximum hole size of 3 mm in the sieve ( 26 c). Overall device (1) according to one of the preceding device claims,
characterized in that
the dust fraction falling through the lowest screening stage ( 26 c) is moistened before being filled into a container ( 13 )
and or
the second last screening stage ( 26 b) only the fines (50 c) and the dust content ( 50 b) fall through and in particular a maximum hole size of 6 mm in the sieve ( 26 b), wherein the sieve (26 b ) non-penetrating portion of the solid fuel is the good portion (50b). Overall device (1) according to one of the preceding device claims,
characterized in that
the fine fraction ( 50 c) which does not pass through the last sieve (26c ) is pressed by an agglomeration device (6), in particular a screw press, into pellets ( 50 c ')
and or
the penultimate screening stage ( 26 b) is preceded by a third last screening stage ( 26 a), in particular a hole size of 40 mm in the sieve ( 26 a) and of a coarse fraction ( 50 a) of the solid fuel ( 50 ) can not be penetrated.
(Exhaust processing device) Overall device (1) according to one of the preceding device claims,
characterized in that
the exhaust air treatment device (21) - A solids separator, in particular a cyclone ( 5 ), comprising an upper air outlet ( 5 a), via which the exhaust air (60) is discharged, in particular in the environment, and - A lower outlet ( 5 b) for the solids content, which is connected to the solids treatment device (31) and the in the cyclone (5) deposited fines ( 50 c) and dust content ( 50 d) of the third last screening stage ( 26 a ) or in particular the second-last screening stage ( 26 b) feeds and or
the overall device (1) has an incoming air conditioning device (41) comprising - A heat exchanger (25) in which the drying air (60) by means of a liquid circuit (24) is heated, and a blower (2) which transports the drying air ( 60) through the heat exchanger (25) and into the drying device (4) , in particular through the holes (19) in the intermediate bottom (23) into the solid fuel (50) lying thereon into pressed. Overall device (1) according to one of the preceding device claims,
characterized in that
the overall device (1) comprises a mixing device for mixing the pellets ( 50 c ') with the crop portion ( 50 b)
and or
the overall device (1) has an electronic control unit (20) for controlling the overall device (1) according to one of the preceding method claims
and or
There is a fan downstream of the drying chamber to keep the interior of the drying chamber under a slight negative pressure. Overall device (1) according to one of the preceding device claims,
characterized in that
the electronic control unit - At least one humidity sensor (18b1, 18b2) which measures the humidity of the surrounding solid fuel (50) , in particular at or near the material outlet (15), in particular at the overflow weir (11), and / or at or close the material inlet (14) is arranged, and or - At least one temperature sensor ( 18 a1, 18 a2) comprises for measuring the surrounding solid fuel (50), in particular at or near the material outlet (15), in particular at the overflow weir (11), and / or at or near the material inlet ( 14) is arranged, - At least one temperature sensor ( 18 c1, 18 c2) comprises for measuring the temperature of the drying air, in particular between the heat exchanger (25) and the air inlet (16) and / or disposed on or in the exhaust duct (12) and or - At least one temperature sensor ( 18 d 1 , 18 d 2 ) comprises for measuring the temperature of the heating liquid, which is arranged in particular on the flow line and / or on the return line of the heat exchanger (25) flowing through heating fluid, and or - At least one humidity sensor ( 18 e 1 , 18 e 2 ), which measures the humidity of the exhaust air (60) and in particular in the air inlet (16) and / or in the exhaust duct (12) is arranged, and - The controller (20) has access to the measurement results of all existing sensors and is in data exchange connection with these. Overall device (1) according to one of the preceding device claims,
characterized in that
the whole device a control element for controlling the supply quantity of solid fuel per unit of time into the material inlet (14) of the drying device (4) , and or a control element for controlling the supply amount of drying air per unit time through the heat exchanger (25) and thus into the drying device (4) , in particular a speed controller for the fan (2), a control element for changing the size of the holes (19) in the intermediate bottom (23) , and - Each control by the controller (20) can be controlled.

Images