CA2969859A1 - Drying unit with a drying area - Google Patents
Drying unit with a drying area Download PDFInfo
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- CA2969859A1 CA2969859A1 CA2969859A CA2969859A CA2969859A1 CA 2969859 A1 CA2969859 A1 CA 2969859A1 CA 2969859 A CA2969859 A CA 2969859A CA 2969859 A CA2969859 A CA 2969859A CA 2969859 A1 CA2969859 A1 CA 2969859A1
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- Prior art keywords
- air
- drying
- stage
- heating
- cooling stage
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B17/00—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement
- F26B17/02—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces
- F26B17/04—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces the belts being all horizontal or slightly inclined
- F26B17/045—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces the belts being all horizontal or slightly inclined the material on the belt being agitated, dispersed or turned over by mechanical means, e.g. by vibrating the belt, by fixed, rotating or oscillating elements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B17/00—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement
- F26B17/02—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces
- F26B17/08—Machines or apparatus for drying materials in loose, plastic, or fluidised form, e.g. granules, staple fibres, with progressive movement with movement performed by belts carrying the materials; with movement performed by belts or elements attached to endless belts or chains propelling the materials over stationary surfaces the belts being arranged in a sinuous or zig-zag path
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/02—Circulating air or gases in closed cycles, e.g. wholly within the drying enclosure
- F26B21/04—Circulating air or gases in closed cycles, e.g. wholly within the drying enclosure partly outside the drying enclosure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B21/00—Arrangements or duct systems, e.g. in combination with pallet boxes, for supplying and controlling air or gases for drying solid materials or objects
- F26B21/06—Controlling, e.g. regulating, parameters of gas supply
- F26B21/10—Temperature; Pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B23/00—Heating arrangements
- F26B23/001—Heating arrangements using waste heat
- F26B23/002—Heating arrangements using waste heat recovered from dryer exhaust gases
- F26B23/005—Heating arrangements using waste heat recovered from dryer exhaust gases using a closed cycle heat pump system ; using a heat pipe system
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B23/00—Heating arrangements
- F26B23/02—Heating arrangements using combustion heating
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/52—Heat recovery pumps, i.e. heat pump based systems or units able to transfer the thermal energy from one area of the premises or part of the facilities to a different one, improving the overall efficiency
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Drying Of Solid Materials (AREA)
- Treatment Of Sludge (AREA)
- Road Signs Or Road Markings (AREA)
Abstract
According to the invention, a drying installation (10) with a drying area (14) is made available for drying bulk material (16) such as pre-granulated sewage sludge, in which an air removal device (32) for removing exhaust air (30) from the drying area (14) and an air delivery device (28) for delivering additional air into the drying area (14) are provided, in which an air cooler (38) with a first air-cooling stage (36) and a second air-cooling stage (44) for cooling the exhaust air (30) and an air heater (62) with a first air-heating stage (64) and a second air-heating stage (72) for heating the additional air (26) are provided, and in which an energy recovery device (70) is provided for returning energy from the first air-cooling stage (36) to the first air-heating stage (64).
Description
a CA 02969859 2017-06-06 Description Drying unit with a drying area Background of the invention The invention relates to a drying unit with a drying zone for drying bulk material, such as pregranulated sewage sludge, in which an air discharge device is provided for discharging exhaust air from the drying zone and an air supply device for feeding supply air into the drying zone.
DE 20 2009 001 935 U1 discloses a single-belt dryer for the drying of, for example, wood chips or wood sawdust with warm air, in which the related drying zone is subdi-vided into sections. A part of the warm air should be circulated in order to save ener-gy. For this purpose, exhaust air is removed from the drying zone and recycled back into the drying zone as supply air.
Underlying objective The invention is based on the objective to create a drying unit through which a partic-ularly energy-saving and dust-free drying of bulk goods is possible.
Solution according to the invention
DE 20 2009 001 935 U1 discloses a single-belt dryer for the drying of, for example, wood chips or wood sawdust with warm air, in which the related drying zone is subdi-vided into sections. A part of the warm air should be circulated in order to save ener-gy. For this purpose, exhaust air is removed from the drying zone and recycled back into the drying zone as supply air.
Underlying objective The invention is based on the objective to create a drying unit through which a partic-ularly energy-saving and dust-free drying of bulk goods is possible.
Solution according to the invention
2 According to the invention, this objective is achieved with a drying unit with a drying area for drying bulk materials, such as sewage sludge in pre-granulated form or op-tionally also sawdust. Herein an air discharge device for discharging exhaust air from the drying area and an air supply device for supplying supply air into the drying area are provided, at which point the drying section is provided with an air cooling device with a first air-cooling stage and a second air-cooling stage for cooling the exhaust air, and an air heating unit with a first air heating stage and a second air heating stage for heating the supply air, and in which an energy recovery device is provided for returning energy from the first air cooling stage to the first air heating stage.
The air discharge device according to the invention is provided with two air cooling stages. By using these two air cooling stages, it is possible to cool the exhaust air so strongly that moisture can be condensed out of this exhaust air.
The exhaust air discharged from the drying zone of a drying unit for bulk material is, of course, strongly saturated with moisture and is therefore not directly suitable to simply feed back into the drying zone as supply air without special processing. Ac-cording to the invention, however, the exhaust air is cooled so strongly that the mois-ture contained therein can be condensed and discharged as condensed water from the two air cooling stages.
Thereafter, the exhaust air is driven according to the invention through two air heating stages. There, the exhaust air is heated to such an extent that it can be fed back into the drying area as supply air in order to be used again for the drying of the bulk mate-rial there.
The essential advantage of such recirculation of exhaust air from the drying area as supply air for the drying area is that no or only comparatively little outgoing air needs to be discharged into the environment of the drying unit. This outgoing air to be ex-
The air discharge device according to the invention is provided with two air cooling stages. By using these two air cooling stages, it is possible to cool the exhaust air so strongly that moisture can be condensed out of this exhaust air.
The exhaust air discharged from the drying zone of a drying unit for bulk material is, of course, strongly saturated with moisture and is therefore not directly suitable to simply feed back into the drying zone as supply air without special processing. Ac-cording to the invention, however, the exhaust air is cooled so strongly that the mois-ture contained therein can be condensed and discharged as condensed water from the two air cooling stages.
Thereafter, the exhaust air is driven according to the invention through two air heating stages. There, the exhaust air is heated to such an extent that it can be fed back into the drying area as supply air in order to be used again for the drying of the bulk mate-rial there.
The essential advantage of such recirculation of exhaust air from the drying area as supply air for the drying area is that no or only comparatively little outgoing air needs to be discharged into the environment of the drying unit. This outgoing air to be ex-
3 tracted would, at the same time, be strongly contaminated with dust from the drying area, on the other hand it would be odour-laden and would therefore have to be fil-tered first or otherwise processed before it could be released into the environment.
According to the invention, energy is, specifically by means of an energy recovery device, discharged from the first air-cooling stage and supplied to the first air-heating stage.
At the first air-cooling stage, the exhaust air discharged is still comparatively warm so that a comparatively high energy potential can be developed there. According to the invention, this recovered energy is advantageously used to reheat the exhaust air after it has been completely cooled and condensed out. For this purpose, the energy is supplied to the first air-heating stage, at which the supply air to be heated is still comparatively cold.
Thus, according to the invention, almost all of the energy discharged from the exhaust air can be fed back to the supply air. At the same time it is ensured, according to the invention, that little or no outgoing air need be discharged into the environment from the drying area of the drying unit.
At the first air-cooling stage, the exhaust air is preferably cooled from 90 to up to 70 Celsius, preferably from 85 to 75 Celsius. Here, advantageously, up to 5 grams of water per kilogram of exhaust air are discharged. At the second air-cooling stage, the exhaust air is then further cooled to up to 45 Celsius, preferably 50 Celsius. Here, up to 65 grams of water per kilogram of exhaust air are discharged. The supply air is then advantageously heated, at the first air-heating stage, to between 45 and Celsius, most preferably to 50 Celsius.
According to the invention, energy is, specifically by means of an energy recovery device, discharged from the first air-cooling stage and supplied to the first air-heating stage.
At the first air-cooling stage, the exhaust air discharged is still comparatively warm so that a comparatively high energy potential can be developed there. According to the invention, this recovered energy is advantageously used to reheat the exhaust air after it has been completely cooled and condensed out. For this purpose, the energy is supplied to the first air-heating stage, at which the supply air to be heated is still comparatively cold.
Thus, according to the invention, almost all of the energy discharged from the exhaust air can be fed back to the supply air. At the same time it is ensured, according to the invention, that little or no outgoing air need be discharged into the environment from the drying area of the drying unit.
At the first air-cooling stage, the exhaust air is preferably cooled from 90 to up to 70 Celsius, preferably from 85 to 75 Celsius. Here, advantageously, up to 5 grams of water per kilogram of exhaust air are discharged. At the second air-cooling stage, the exhaust air is then further cooled to up to 45 Celsius, preferably 50 Celsius. Here, up to 65 grams of water per kilogram of exhaust air are discharged. The supply air is then advantageously heated, at the first air-heating stage, to between 45 and Celsius, most preferably to 50 Celsius.
4 . CA 02969859 2017-06-06 , On the drying unit according to the invention, the first air-cooling stage is, according to the invention, advantageously designed as a tubular heat exchanger, which is designed in particular with a cross countercurrent guide. The heat exchanger of this type has proven to be particularly reliable and practicable in the temperature ranges provided according to the invention. The tubular heat exchanger can also be advan-tageously cleaned so that dust from the exhaust air can also be deposited in it. Espe-cially preferred is that the second air-cooling stage is likewise configured as a tubular heat exchanger, which is designed in particular with a cross countercurrent guide.
Furthermore, according to the invention, an energy discharge device for discharging energy from the second air-cooling stage to an external heat sink is preferably pro-vided. At the second air-cooling stage, the exhaust air is located at a lower energy level than at the first air-cooling stage, but the waste heat of this second air-cooling stage can also be advantageously used. According to the alternative embodiment according to the invention, this is done by delivering this energy to an external heat sink, for example a building climate control, a fermentation process or a district heat-ing grid.
A cleaning device for cleaning the first and/or second air-cooling stage by means of a process water is preferably also provided on the drying unit according to the inven-tion. The cleaning with process water is particularly efficient, since the process water can then also be used to transfer the accompanying absorbed energy.
Furthermore, a third air-cooling stage, which is particularly designed as an air washer, is preferably provided. With the air washer, a large part of the moisture contained in the exhaust air can be re-condensed as water. In addition, the exhaust air is cleaned with the air washer and the dust contained therein is flushed out. Thus it can be par-ticularly ensured that none or almost none of the outgoing air is discharged from the drying unit according to the invention into its surroundings. At the third air-cooling
Furthermore, according to the invention, an energy discharge device for discharging energy from the second air-cooling stage to an external heat sink is preferably pro-vided. At the second air-cooling stage, the exhaust air is located at a lower energy level than at the first air-cooling stage, but the waste heat of this second air-cooling stage can also be advantageously used. According to the alternative embodiment according to the invention, this is done by delivering this energy to an external heat sink, for example a building climate control, a fermentation process or a district heat-ing grid.
A cleaning device for cleaning the first and/or second air-cooling stage by means of a process water is preferably also provided on the drying unit according to the inven-tion. The cleaning with process water is particularly efficient, since the process water can then also be used to transfer the accompanying absorbed energy.
Furthermore, a third air-cooling stage, which is particularly designed as an air washer, is preferably provided. With the air washer, a large part of the moisture contained in the exhaust air can be re-condensed as water. In addition, the exhaust air is cleaned with the air washer and the dust contained therein is flushed out. Thus it can be par-ticularly ensured that none or almost none of the outgoing air is discharged from the drying unit according to the invention into its surroundings. At the third air-cooling
5 stage the exhaust air is advantageously cooled to up to 35 Celsius, advantageously to 40 Celsius. Here, up to another 40 grams of water per kilogram of exhaust air are discharged. Exhaust air cooled in this way then only has a moisture content of less than 50 grams of water per kilogram of air.
According to the invention, the first air-heating stage is also preferably designed as a tubular heat exchanger. At the first air-heating stage also, the aforementioned ad-vantages with regard to efficiency of the energy transfer and cleaning can be achieved. In addition, cost advantages result because relatively large numbers of common parts can be installed in the drying unit.
The second air-heating stage is preferably designed as a pre-heater to which energy is supplied from an external heat source. A heating coil of an external heater advan-tageously serves as the external heat source. At the second air-heating stage, the supply air is preferably heated to a temperature of approximately 55 Celsius.
In addition, according to the invention, a third air-heating stage, which is designed in particular as a combustion heater, is preferably provided. With the combustion heater, the supply air can be heated to temperatures of between 135 and 280 Celsius and above. At such a temperature, the supply air can then be fed directly back to the drying area to dry the bulk material.
Subsequently, an air transfer unit for transferring cooled exhaust air from the air dis-charge device as air to be heated to the air supply device is advantageously also provided on the drying unit according to the invention. The air transfer device thus provides the connecting link between the exhaust air and the supply air, to produce circulating air. As an alternative to this recirculation of air, the solution according to the invention can also be used to obtain, with the energy from exhaust air which is deposited as outgoing air, that energy with which the fresh air is pre-heated.
Corre-
According to the invention, the first air-heating stage is also preferably designed as a tubular heat exchanger. At the first air-heating stage also, the aforementioned ad-vantages with regard to efficiency of the energy transfer and cleaning can be achieved. In addition, cost advantages result because relatively large numbers of common parts can be installed in the drying unit.
The second air-heating stage is preferably designed as a pre-heater to which energy is supplied from an external heat source. A heating coil of an external heater advan-tageously serves as the external heat source. At the second air-heating stage, the supply air is preferably heated to a temperature of approximately 55 Celsius.
In addition, according to the invention, a third air-heating stage, which is designed in particular as a combustion heater, is preferably provided. With the combustion heater, the supply air can be heated to temperatures of between 135 and 280 Celsius and above. At such a temperature, the supply air can then be fed directly back to the drying area to dry the bulk material.
Subsequently, an air transfer unit for transferring cooled exhaust air from the air dis-charge device as air to be heated to the air supply device is advantageously also provided on the drying unit according to the invention. The air transfer device thus provides the connecting link between the exhaust air and the supply air, to produce circulating air. As an alternative to this recirculation of air, the solution according to the invention can also be used to obtain, with the energy from exhaust air which is deposited as outgoing air, that energy with which the fresh air is pre-heated.
Corre-
6 = CA 02969859 2017-06-06 spondingly, an admixing device for admixing the heated air supply in fresh air is also advantageously proposed, according to the invention.
Brief description of the drawing An exemplary embodiment of the solution according to the invention is explained in more detail below with the accompanying schematic drawing. The illustration shows a circuit diagram of an exemplary embodiment of a drying unit according to the inven-tion.
Detailed description of the exemplary embodiment In the illustration a drying unit 10 is shown, which is designed with a housing 12 with which a drying area 14 is created for bulk material 16. In front of the housing 12, located relative to the figure on the right, is a feeding station 18 for the bulk material 16 to be dried, in the present case, sewage sludge in pre-granulated form or similar products. Feeding station 18 guides the bulk material 16 to an upper revolving drying belt 20 with which the bulk material 16 is laid out as a layer and led through the drying area 14 from the right to the left in relation to the illustration. On the left side of the housing 12, the upper revolving drying belt 20 emerges from the drying area 14 and delivers the bulk material 16 to a lower revolving drying belt 22, which is located below. The lower revolving drying belt 22 conveys the bulk material 16 back through the drying area 14, and then out on the right-hand side of the housing 12 as a dried bulk material 16.
Below the housing 12 are several circulating air fans 24, with which warmed or heat-ed supply air 26 can be introduced into the drying area 14 and then circulated therein.
In the present case, eight circulating air fans 24 are provided, wherein each of these circulating air fans 24 is assigned to a separate partial area or a closed area (not
Brief description of the drawing An exemplary embodiment of the solution according to the invention is explained in more detail below with the accompanying schematic drawing. The illustration shows a circuit diagram of an exemplary embodiment of a drying unit according to the inven-tion.
Detailed description of the exemplary embodiment In the illustration a drying unit 10 is shown, which is designed with a housing 12 with which a drying area 14 is created for bulk material 16. In front of the housing 12, located relative to the figure on the right, is a feeding station 18 for the bulk material 16 to be dried, in the present case, sewage sludge in pre-granulated form or similar products. Feeding station 18 guides the bulk material 16 to an upper revolving drying belt 20 with which the bulk material 16 is laid out as a layer and led through the drying area 14 from the right to the left in relation to the illustration. On the left side of the housing 12, the upper revolving drying belt 20 emerges from the drying area 14 and delivers the bulk material 16 to a lower revolving drying belt 22, which is located below. The lower revolving drying belt 22 conveys the bulk material 16 back through the drying area 14, and then out on the right-hand side of the housing 12 as a dried bulk material 16.
Below the housing 12 are several circulating air fans 24, with which warmed or heat-ed supply air 26 can be introduced into the drying area 14 and then circulated therein.
In the present case, eight circulating air fans 24 are provided, wherein each of these circulating air fans 24 is assigned to a separate partial area or a closed area (not
7 = CA 02969859 2017-06-06 shown in detail) within the drying area 14. The partial areas extend over a respective partial length of the two drying belts 20 and 22, located one above the other.
Using the air-circulating fans 24, both drying belts 20 and 22 are fed with supply air 26. The supply air 26 is supplied via a central supply air fan acting as the air supply unit 28 to the circulating air fans 24.
Based on the illustration, at the left end area of the drying area 14, exhaust air 30 with a temperature of approx. 85 Celsius and a moisture content of approx. 150 grams of water per kilogram of air is removed from the drying area 14 to two dedicated sec-tions using a central exhaust air fan as an air discharge device 32. This exhaust air 30 is re-used, as will be explained below, and can be referred to accordingly as recu-peration air. Accordingly, the exhaust fan can also be referred to as a recuperation fan.
The air discharge device 32 feeds the exhaust air 30 into an air duct or an air route 34, via which the exhaust air 28 reaches the first air-cooling stage 36 of an air cooling unit 38. The first air-cooling stage 36 is designed as a heat exchanger or transformer, which in addition to the exhaust air 30 is also perfused by a first heat carrier 40 with an inlet temperature of approximately 50 Celsius. The exhaust air 30 cools down in the heat exchanger, wherein the heat carrier 40 is heated to an outlet temperature of approximately 60 , and moisture contained in the exhaust air 30 is deposited to a small extent as condensed water. The condensed water is discharged downwards, in particular together with process water 42, and cleaned by means of such heat ex-changer of the first air-cooling stage 36. At the first air-cooling stage 36, the exhaust air 30 is thus brought to a temperature of approximately 75 C and a moisture content of approximately 135 grams of water per kilogram of air.
The exhaust air 30 passes from the first air-cooling stage 36 through the air duct 34 into a second air-cooling stage 44. The second air-cooling stage 44 can be perfused
Using the air-circulating fans 24, both drying belts 20 and 22 are fed with supply air 26. The supply air 26 is supplied via a central supply air fan acting as the air supply unit 28 to the circulating air fans 24.
Based on the illustration, at the left end area of the drying area 14, exhaust air 30 with a temperature of approx. 85 Celsius and a moisture content of approx. 150 grams of water per kilogram of air is removed from the drying area 14 to two dedicated sec-tions using a central exhaust air fan as an air discharge device 32. This exhaust air 30 is re-used, as will be explained below, and can be referred to accordingly as recu-peration air. Accordingly, the exhaust fan can also be referred to as a recuperation fan.
The air discharge device 32 feeds the exhaust air 30 into an air duct or an air route 34, via which the exhaust air 28 reaches the first air-cooling stage 36 of an air cooling unit 38. The first air-cooling stage 36 is designed as a heat exchanger or transformer, which in addition to the exhaust air 30 is also perfused by a first heat carrier 40 with an inlet temperature of approximately 50 Celsius. The exhaust air 30 cools down in the heat exchanger, wherein the heat carrier 40 is heated to an outlet temperature of approximately 60 , and moisture contained in the exhaust air 30 is deposited to a small extent as condensed water. The condensed water is discharged downwards, in particular together with process water 42, and cleaned by means of such heat ex-changer of the first air-cooling stage 36. At the first air-cooling stage 36, the exhaust air 30 is thus brought to a temperature of approximately 75 C and a moisture content of approximately 135 grams of water per kilogram of air.
The exhaust air 30 passes from the first air-cooling stage 36 through the air duct 34 into a second air-cooling stage 44. The second air-cooling stage 44 can be perfused
8 by means of a second heat carrier 46 with an inlet temperature of approximately 10 C and an outlet temperature of approximately 30 C, which can transmit the heat transmitted into it to an external heat sink of a building heating system. The second air cooling stage 44 thus further cools down the exhaust air 30 to a temperature be-low its dew point temperature (about 58 C, whereby further contained moisture is condensed out and discharged as condensation water. The second air-cooling stage 44 also has to be cleaned using process water 42 and, moreover, presents a washer 48, which washes the exhaust air 30 flowing through it and thereby cleans the dust contained therein from the bulk material 16 to be dried. At the second air-cooling stage 44, the exhaust air 30 is thus brought to a temperature of approximately and a moisture content of approximately 86 grams of water per kilogram of air.
Subsequently, the exhaust air 30 already cooled at the first air-cooling stage 36 and the second air-cooling stage 44 reaches a third air cooling stage 50. This third air cooling stage 50 is designed as an air washer, in which process water 42 with a tem-perature of approx. 10 C is sprinkled directly above and through the exhaust air 30.
Accordingly, the majority of the remaining moisture is condensed out of the exhaust air 30 at this third air-cooling stage 50 and is discharged as condensed water with the process water 42. For this purpose, a permanently-operating washer 52 is provided at the third air-cooling stage 50. At the third air-cooling stage 50, the exhaust air 30 is thus brought to a temperature of approximately 40 C and a moisture content of ap-proximately 50 grams of water per kilogram of air.
Viewed in the direction of flow of the exhaust air 30, an air flap or a valve 54 is pro-vided behind or downstream from the third air-cooling stage 50 in the air duct 34, with which a small part of the exhaust air 30 can optionally be discharged from the air duct 34 using a outgoing air fan 56 at a temperature of approximately 40 C, and can be expelled, if appropriate, as outgoing air 58, through a filter into the surroundings of the drying unit 10.
Subsequently, the exhaust air 30 already cooled at the first air-cooling stage 36 and the second air-cooling stage 44 reaches a third air cooling stage 50. This third air cooling stage 50 is designed as an air washer, in which process water 42 with a tem-perature of approx. 10 C is sprinkled directly above and through the exhaust air 30.
Accordingly, the majority of the remaining moisture is condensed out of the exhaust air 30 at this third air-cooling stage 50 and is discharged as condensed water with the process water 42. For this purpose, a permanently-operating washer 52 is provided at the third air-cooling stage 50. At the third air-cooling stage 50, the exhaust air 30 is thus brought to a temperature of approximately 40 C and a moisture content of ap-proximately 50 grams of water per kilogram of air.
Viewed in the direction of flow of the exhaust air 30, an air flap or a valve 54 is pro-vided behind or downstream from the third air-cooling stage 50 in the air duct 34, with which a small part of the exhaust air 30 can optionally be discharged from the air duct 34 using a outgoing air fan 56 at a temperature of approximately 40 C, and can be expelled, if appropriate, as outgoing air 58, through a filter into the surroundings of the drying unit 10.
9 The main flow of the exhaust air 30 that is cooled at the three air cooling stages 36, 44 and 50 is however passed through air duct 34, which in this area acts as an air transfer device 60 from the exhaust air side to the air supply side of the drying unit 10.
With the air duct 34, the cooled and condensed exhaust air 30 is fed as air supply 26 to an air heating device 62, whereupon it is heated again to the temperature neces-sary for subsequent drying.
The air heating device 62 is designed with a first air-heating stage 64, to which the energy required for heating is transported by means of the first heat carrier 40 from the first air cooling stage 36. The first heat carrier 40 is conveyed back by a heat transfer medium line 66 through a heat transfer pump 68 at a temperature of about 60 C, from the first air-cooling stage 34, to the first air-heating stage 64 and at a temperature of approximately 50 C. The heat transfer line 66 and the heat transfer pump 68 thus act as an energy return device 70. The supply air 26 is heated to a temperature of approximately 50 C at the first air-heating stage 64.
The air heating device 62 further includes a second air-heating stage 72, at which the energy required for the heating of the supply air 26 is supplied from an external heat source, in the present case an external heater, with a third heat carrier 74, with a temperature of approximately 80 C. The supply air 26 is heated to a temperature of approximately 55 Celsius.
As a third air-heating stage 76, a combustion heater is provided for the air heating device 62, through which the supply air 26 to be heated is fed and in which the latter is then heated by a flame. For this purpose, both fuel 78 and combustion air 80 are supplied to the third air-heating stage 76. Using the third air-heating stage 76, the supply air 26 is heated to a temperature of approximately 280 C before it is metered into the drying area 14 again by the air feeding unit 28.
With the air duct 34, the cooled and condensed exhaust air 30 is fed as air supply 26 to an air heating device 62, whereupon it is heated again to the temperature neces-sary for subsequent drying.
The air heating device 62 is designed with a first air-heating stage 64, to which the energy required for heating is transported by means of the first heat carrier 40 from the first air cooling stage 36. The first heat carrier 40 is conveyed back by a heat transfer medium line 66 through a heat transfer pump 68 at a temperature of about 60 C, from the first air-cooling stage 34, to the first air-heating stage 64 and at a temperature of approximately 50 C. The heat transfer line 66 and the heat transfer pump 68 thus act as an energy return device 70. The supply air 26 is heated to a temperature of approximately 50 C at the first air-heating stage 64.
The air heating device 62 further includes a second air-heating stage 72, at which the energy required for the heating of the supply air 26 is supplied from an external heat source, in the present case an external heater, with a third heat carrier 74, with a temperature of approximately 80 C. The supply air 26 is heated to a temperature of approximately 55 Celsius.
As a third air-heating stage 76, a combustion heater is provided for the air heating device 62, through which the supply air 26 to be heated is fed and in which the latter is then heated by a flame. For this purpose, both fuel 78 and combustion air 80 are supplied to the third air-heating stage 76. Using the third air-heating stage 76, the supply air 26 is heated to a temperature of approximately 280 C before it is metered into the drying area 14 again by the air feeding unit 28.
10 = CA 02969859 2017-06-06 Finally, it should be noted that all features which are mentioned in the application documents, and in particular in the dependent claims, are intended to receive inde-pendent protection, individually or in any combination, despite any formal reference made to one or more specific claims.
11 List of reference numbers Drying unit 5 12 Housing 14 Drying area 16 Bulk material 18 Feeding station Upper revolving drying belt 10 22 Lower revolving drying belt 24 Circulating air fan 26 Supply air 28 Air feeding unit Exhaust air 15 32 Air discharge device 34 Air duct 36 First air-cooling stage 38 Air cooling unit First heat carrier 20 42 Process water 44 Second air-cooling stage 46 Second heat carrier 48 Washer Third air-cooling stage 25 52 Washer 54 Valve 56 Outgoing air fan 58 Outgoing air Air transfer device
12 62 Air heating device 64 First air-heating stage 66 Heat transfer line 68 Heat transfer pump 70 Energy recovery device 72 Second air-heating stage 74 Third heat carrier 76 Third air-heating stage 78 Fuel 80 Combustion air
Claims (10)
1. Drying unit (10) with a drying area (14) for drying bulk materials (16), such as pregranulated sewage sludge, - at which an air discharge device (32) for discharging exhaust air (30) from the drying area (14) and an air supply device (28) for supplying supply air (26) into the drying area (14) are provided, - at which an air cooling unit (38) with a first air-cooling stage (36) and a second air-cooling stage (44) for cooling the exhaust air (30) and an air heating unit (62) with a first air-heating stage (64) and a second air-heating stage (72) for heating the supply air (26), are provided and - at which an energy recovery device (70) for returning energy from the first air-cooling stage (36) to the first air-heating stage is provided.
2. Drying unit according to Claim 1, whereby the first air-cooling stage (36) is designed as a tubular heat exchanger, which is designed in particular with a cross countercurrent guide.
3. Drying unit according to Claim 1 or 2, whereby the second air-cooling stage (44) is also designed as a tubular heat exchanger, which is designed in particular with a cross countercurrent guide.
4. Drying unit according to one of Claims 1 to 3, in which an energy extraction device is provided for discharging energy from the second air-cooling stage (44) to an external heat sink.
5. Drying unit according to one of Claims 1 to 4, in which a cleaning device is provided for cleaning the first and/or second air-cooling stage (36, 44) using process water (42).
6. Drying unit according to one of Claims 1 to 5, in which the third air-cooling stage (50) is designed especially as an air washer.
7. Drying unit according to one of Claims 1 to 6, in which the first air heating stage (64) is designed as a tubular heat exchanger.
8. Drying unit according to one of Claims 1 to 7, in which the second air-heating stage (72) is designed as pre-heating unit which is fed energy from an external heat source
9. Drying unit according to one of Claims 1 to 8, in which a third air-heating stage (76), which is particularly configured as a combustion heater, is provided.
10. Drying unit according to one of Claims 1 to 9, whereby an air transfer device (60) for transferring cooled exhaust air (30) from the air discharge device (32) as supply air to be heated (26) in the air feeding device (28) is provided.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/DE2014/100432 WO2016091237A1 (en) | 2014-12-08 | 2014-12-08 | Drying installation with a drying area |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2969859A1 true CA2969859A1 (en) | 2016-06-16 |
Family
ID=52434464
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2969859A Abandoned CA2969859A1 (en) | 2014-12-08 | 2014-12-08 | Drying unit with a drying area |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP3230671B2 (en) |
| CN (1) | CN107429970B (en) |
| CA (1) | CA2969859A1 (en) |
| DE (1) | DE112014007239A5 (en) |
| DK (1) | DK3230671T3 (en) |
| ES (1) | ES2773884T3 (en) |
| HR (1) | HRP20200295T1 (en) |
| LT (1) | LT3230671T (en) |
| PL (1) | PL3230671T3 (en) |
| PT (1) | PT3230671T (en) |
| SI (1) | SI3230671T1 (en) |
| WO (1) | WO2016091237A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3540349A4 (en) * | 2016-11-30 | 2019-09-18 | Mazda Motor Corporation | Coating drying method and device therefor |
| WO2023242483A1 (en) * | 2022-06-17 | 2023-12-21 | Spinnova Oyj | Method for recovering thermal energy in a material drying process, heat recovery system, and arrangement for drying material |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109485222B (en) * | 2018-10-26 | 2023-11-24 | 广东工业大学 | Heat pump type temperature division area drying system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE8100042L (en) * | 1981-01-07 | 1982-07-08 | Technoscript Ab | METHOD AND DEVICE FOR DRYING MATERIALS IN A DRYER |
| DE3321178C2 (en) * | 1983-06-11 | 1985-12-05 | IPRO Industrieprojekt GmbH, 3300 Braunschweig | Process for the low-temperature drying of pre-drained beet pulp |
| EP0143855A1 (en) | 1983-11-02 | 1985-06-12 | H. Krantz GmbH & Co. | Method of waste heat recovery |
| DE19520228A1 (en) * | 1995-06-01 | 1996-12-05 | Gimborn Probat Werke | Arrangement for roasting bulk plant material, in particular coffee beans |
| DE19654093C2 (en) * | 1996-12-23 | 2000-04-13 | Alb Klein Umwelttechnik Gmbh | Process for low-temperature drying of moist material and device for carrying out the process |
| DE202008014503U1 (en) | 2008-10-31 | 2009-03-12 | Riela - Getreidetechnik Karl-Heinz Knoop E.K. | belt dryers |
| FR2953006B1 (en) * | 2009-11-24 | 2012-11-09 | Vinci Environnement | INSTALLATION AND METHOD OF DRYING WATER LOADING PRODUCT |
| AT510487B1 (en) * | 2010-10-07 | 2012-09-15 | Mci Man Ct Innsbruck Internationale Hochschule Gmbh | DRYING PROCESS AND DRYING SYSTEM |
| CN202254719U (en) * | 2011-08-18 | 2012-05-30 | 天津商业大学 | Casting machine drying box with heat energy recovery function |
-
2014
- 2014-12-08 EP EP14833119.2A patent/EP3230671B2/en active Active
- 2014-12-08 SI SI201431484T patent/SI3230671T1/en unknown
- 2014-12-08 ES ES14833119T patent/ES2773884T3/en active Active
- 2014-12-08 DE DE112014007239.7T patent/DE112014007239A5/en not_active Withdrawn
- 2014-12-08 LT LTEP14833119.2T patent/LT3230671T/en unknown
- 2014-12-08 DK DK14833119.2T patent/DK3230671T3/en active
- 2014-12-08 PL PL14833119T patent/PL3230671T3/en unknown
- 2014-12-08 CN CN201480083926.XA patent/CN107429970B/en active Active
- 2014-12-08 WO PCT/DE2014/100432 patent/WO2016091237A1/en active Application Filing
- 2014-12-08 CA CA2969859A patent/CA2969859A1/en not_active Abandoned
- 2014-12-08 PT PT148331192T patent/PT3230671T/en unknown
-
2020
- 2020-02-21 HR HRP20200295TT patent/HRP20200295T1/en unknown
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3540349A4 (en) * | 2016-11-30 | 2019-09-18 | Mazda Motor Corporation | Coating drying method and device therefor |
| US11262127B2 (en) | 2016-11-30 | 2022-03-01 | Mazda Motor Corporation | Coating drying method and device therefor |
| WO2023242483A1 (en) * | 2022-06-17 | 2023-12-21 | Spinnova Oyj | Method for recovering thermal energy in a material drying process, heat recovery system, and arrangement for drying material |
Also Published As
| Publication number | Publication date |
|---|---|
| EP3230671A1 (en) | 2017-10-18 |
| PT3230671T (en) | 2020-03-05 |
| WO2016091237A1 (en) | 2016-06-16 |
| PL3230671T3 (en) | 2020-06-01 |
| HRP20200295T1 (en) | 2020-05-29 |
| EP3230671B1 (en) | 2019-12-25 |
| EP3230671B2 (en) | 2022-04-27 |
| LT3230671T (en) | 2020-03-10 |
| DK3230671T3 (en) | 2020-03-02 |
| CN107429970B (en) | 2020-09-29 |
| CN107429970A (en) | 2017-12-01 |
| ES2773884T3 (en) | 2020-07-15 |
| SI3230671T1 (en) | 2020-03-31 |
| DE112014007239A5 (en) | 2017-09-28 |
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Legal Events
| Date | Code | Title | Description |
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| FZDE | Discontinued |
Effective date: 20210302 |