Device for drying material

Abstract

Device (1) for drying material, in particular biomass, for example sewage sludge or wastewater, comprising at least one drying chamber (2), wherein a cascade dryer (3) with one or more drying surface pairs (4) is arranged in the drying chamber (2), wherein the cascade dryer (4) is provided for drying material from a first dry matter content, and at least one technical room (5), wherein a pre-drying plant (6) is arranged in the technical room (5) upstream of the drying chamber (2) from the perspective of the material to be dried, wherein the pre-drying plant (6) is provided for drying material with a second dry matter content that is lower than the first dry matter content, wherein the pre-drying system (6) is designed to be switchable on for pre-drying the material depending on the dry matter content of the material to be dried, so that if the dry matter content is equal to or greater than the first dry matter content, the material can be fed directly to the drying chamber (2) and if the dry matter content is less than the first dry matter content, it can be dried or is dried by means of the pre-drying system (6) up to a dry matter content that is equal to or greater than the first dry matter content.

Description

[0001] The invention relates to a device for drying material, in particular biomass, for example sewage sludge or wastewater. The biomass can also be milk sludge, brewer's grains, digestate, liquid manure, animal manure, or biogas digestate. The material can also be moistened or moisture-containing mass or sludge.

[0002] A known problem with such devices for drying material is that they can only be used above a certain dry matter content, i.e. the material may be too moist to be effectively dried in these devices.

[0003] The invention is based on the objective of providing a new device for drying material. In particular, a device is to be proposed with which even the drying of particularly moist material is possible.

[0004] This problem is solved by a device having the features of claim 1. Advantageous embodiments and further developments are specified in the dependent claims.

[0005] The inventive device for drying material comprises at least one drying chamber, wherein a cascade dryer with one or more pairs of drying surfaces is arranged in the drying chamber, wherein the cascade dryer is provided for drying material from a first dry matter content, and at least one technical room, wherein a pre-drying system is arranged in the technical room upstream of the drying chamber from the perspective of the material to be dried, wherein the pre-drying system is provided for drying material from a second dry matter content, which is lower than the first dry matter content. wherein the pre-drying system is designed to be switchable on depending on the dry matter content of the material to be dried, so that if the dry matter content is equal to or greater than the first dry matter content, the material can be fed directly into the drying chamber and if the dry matter content is less than the first dry matter content, it can be dried or dried by means of the pre-drying system up to a dry matter content that is equal to or greater than the first dry substrate content.

[0006] In other words: If the dry substrate content is sufficient (i.e., equal to or greater than the first dry substrate content), the material to be dried is fed directly into the drying chamber without pre-drying. If the dry substrate content is insufficient (i.e., less than the first dry substrate content), it is first dried in the pre-drying system and only fed into the drying chamber once the first dry substrate content is reached or exceeded.

[0007] The technical room could, for example, be a dust-free room.

[0008] The advantages of the invention lie particularly in its small size. The invention provides a device for drying materials in a very compact design. A further advantage is that materials with a dry matter content of TS2-5 (e.g., wastewater) can be dried. The device also operates with minimal heat, especially at water temperatures as low as 40 °C in the heating system of the drying chamber. Furthermore, a self-regulating heat pump can be integrated.

[0009] The material drying device is particularly suitable for use in wastewater treatment plants, industrial wastewater treatment plants, the hotel industry, campgrounds such as campsites or refugee camps, allotment gardens, and the food industry. The device is also suitable for sludge containing volatile and / or explosive substances. Specifically, the screw press drying device is designed for wastewater treatment plants with a sludge volume of 200-2000 m³ / h. 3 / year planned.

[0010] The first dry matter content is particularly in the range of TS14 to TS18. Preferably, the first dry matter content has a value of TS16. The second dry matter content is particularly in the range of TS1 to TS6, preferably TS2 to TS5, and most preferably has a value of TS3.

[0011] Preferably, the pre-drying plant includes at least one mechanical dewatering unit, in particular a screw press.

[0012] Preferably, the device comprises a conduit, in particular a sludge drain, by means of which the material discharged by the mechanical dewatering unit can be directed into the drying chamber, and in the drying chamber, in particular onto the drying surface pairs, especially preferably onto the uppermost drying surface pair.

[0013] The pre-drying system may include a feed device, for example a pump, for supplying the material, for example from an external source, to the mechanical dewatering unit.

[0014] Preferably, the pre-drying system includes a polymer preparation unit for adding polymers to the material. The polymers added to the material by the polymer preparation unit cause the flocculation of solids within the material. This flocculation facilitates the separation of water from the solids. Furthermore, the consistency and handling of the dewatered material can be improved. More effective dewatering leads to a lower water content in the material and thus an increase in the dry matter content.

[0015] It is possible for the polymer processing unit to be located upstream of the mechanical dewatering unit. The polymer processing unit is thus positioned, in particular, between the feeding device and the mechanical dewatering unit.

[0016] According to one embodiment of the invention, a heat pump and / or a heat exchanger is arranged in the technical room. The heat pump can include a control unit that automatically activates and / or regulates the heat pump when predefined limit values ​​are reached.

[0017] Preferably, one or more, preferably two, air ducts are arranged in the technical room. Particularly preferred are two air ducts that run parallel and / or are arranged horizontally next to each other. Alternatively, the air ducts can also be arranged vertically one above the other.

[0018] According to one embodiment, an air supply duct and an exhaust air duct are arranged in the drying chamber, the air supply duct and the exhaust air duct preferably being arranged on two opposite chamber walls of the drying chamber. In particular, the air supply duct and the exhaust air duct are arranged on the two opposite narrow sides of the drying chamber.

[0019] Each air duct can be connected at its first end to the exhaust duct of the drying chamber and at its second end to the supply air duct of the drying chamber. In particular, this arrangement results in a recirculating air system, whereby the air circulates at least partially between the exhaust duct and the supply air duct of the drying chamber via the air ducts. From the supply air duct, the air can be transported through the drying chamber to the exhaust duct, and from the exhaust air duct, via the air ducts, to the supply air duct.

[0020] A first air duct section of the air distribution channel preferably runs in the intermediate floor between the drying chamber and the technical room, particularly in the area (in the direction of air flow) after the heating device.

[0021] According to a further development of the invention, a filter device, in particular a cyclone, and especially preferably a horizontal cyclone, is arranged in each air duct. The filter device can have a filter box and / or a dust box, each of which in particular has a quick-release fastener. The material of the cyclone is in particular galvanized steel.

[0022] According to a further embodiment of the invention, a heating device, in particular a fan heater, preferably with integrated recirculation, is arranged in each air duct. The heating device can be located downstream of the filter unit.

[0023] Each air duct preferably includes a second air duct section, which is connected at its first end to the heater and at its second end to the first air duct section in the intermediate floor between the drying chamber and the technical room. The heater can be opened by removing the second air duct section(s).

[0024] Preferably, the technical room is arranged on or mounted on top of the drying chamber. The technical room and / or the drying chamber are each preferably designed as a container or of container construction. For example, the technical room container can be mounted on top of the drying chamber container. The containers can be delivered separately and assembled on-site to form the drying device, for example, by placing the technical room container on top of the drying chamber container.

[0025] Preferably, the drying chamber and / or the technical room each have at least one access door. The access door to the technical room is accessible, in particular, via a ladder or stairs, for example, a spiral staircase. The access door to the technical room is, for example, located on its narrow side.

[0026] The drying chamber can have one or more access doors. The access doors of the drying chamber are typically located along its long side. For example, all necessary connections, such as for water (especially heating water) and electrical systems, can be located on the narrow side of the technical room.

[0027] The drying device, in particular the pre-drying system, may include a water storage unit, especially a tank. The water storage unit is preferably located in the technical room.

[0028] The drying device can include a container for the dried goods. The container is preferably arranged at a distance from the technical area. This makes the container easily replaceable.

[0029] The drying device can include at least one control cabinet, which is located, for example, in the drying chamber and / or in the technical room. Preferably, the control cabinet is a double-door cabinet.

[0030] The drying device may have one or more of the following sensors: water inlet sensor, outlet sensor, heat meter, sensor for sludge water inlet quantity with TS measurement, temperature and humidity sensor (especially external), sensors in or for supply air duct and / or exhaust air duct, sensors for current consumption and / or electrical power, and / or sensors for outlet flow measurement.

[0031] The device is in particular 6m to 9m, preferably 7.5m, long, and / or 2m to 4m, preferably 3m, wide, and / or 5m to 8m, preferably 6.5m, high (thus, with two containers arranged one above the other, each container is approximately 2.5m to 4m, preferably 3.25m, high). The device can weigh, for example, 15t to 25t, in particular 20t.

[0032] The device can be designed in ATEX version to ensure compliance with explosion protection requirements in working environments.

[0033] It can be provided that each drying surface pair has an upper drying surface and a lower drying surface over which the material can be conveyed for drying, wherein each drying surface pair is associated with a conveying device circulating around the upper drying surface with conveying elements for conveying the material over the upper drying surface and the lower drying surface, wherein the upper drying surface and the lower drying surface, as well as the conveying device and its conveying elements, are designed and arranged relative to each other such that the conveying elements for conveying the material over the upper drying surface and for conveying the material over the lower drying surface are moved in opposite directions, wherein the upper drying surface is arranged relative to the lower drying surface in such a way thatthat the material, after being conveyed over the upper drying surface, falls from the upper drying surface to the lower drying surface for subsequent conveying over the lower drying surface.

[0034] It may be provided that at least four or at least eight or at least sixteen pairs of drying surfaces are arranged one above the other, in particular ten pairs of drying surfaces, such that the material can be conveyed or is conveyed successively over all drying surfaces and thereby falls from the lower drying surface of the respective upper pair of drying surfaces to the upper drying surface of the respective lower pair of drying surfaces, until the lower drying surface of the lowest pair of drying surfaces is reached.

[0035] The invention is further explained below with regard to its features and advantages by means of a description of exemplary embodiments and with reference to the accompanying schematic drawings. These show Fig. 1 An embodiment of a drying device according to the invention in a schematic side view without outer walls, Fig. 2 the device according to Fig. 1 in a top view.

[0036] Corresponding parts and components are marked with the same reference symbols in the figures.

[0037] Fig. 1 and Fig. Figure 2 shows a device 1 for drying material, in particular biomass, for example sewage sludge or wastewater. The biomass can also be milk sludge, brewer's grains, digestate, liquid manure, animal manure or biogas digestate. The material can also be moistened or moisture-containing mass or sludge.

[0038] The device 1 comprises a drying chamber 2, wherein a cascade dryer 3 with several drying surface pairs 4 is arranged in the drying chamber 2. The cascade dryer 4 is intended for drying material starting from a certain initial dry matter content. The initial dry matter content has, for example, a value of TS16.

[0039] The device further comprises a technical room 5, wherein a pre-drying unit 6 is arranged upstream of the drying chamber 2 from the perspective of the material to be dried, and which is intended for drying material with a second dry matter content that is lower than the first dry matter content. The second dry matter content is, for example, in the range TS2 to TS5.

[0040] The pre-drying system 6 includes a mechanical dewatering unit 7. The mechanical dewatering unit 7 is a screw press.

[0041] Depending on the dry matter content of the material to be dried, the pre-drying system 6 is designed to be activated for pre-drying the material, so that if the dry matter content is equal to or greater than the first dry matter content, the material can be fed directly into the drying chamber 2, and if the dry matter content is less than the first dry matter content, it is dried by means of the pre-drying system 6 to a dry matter content that is equal to or greater than the first dry matter content, so that after pre-drying in the technical room 5 the material can be fed to the cascade dryer 3 in the drying chamber 2.

[0042] The device 1 further includes a line 22 designed as a sludge drain, by means of which the material which has been pre-dried by the screw press 7 can be directed into the drying chamber 2, and in the drying chamber 2 onto the uppermost drying surface pair 4 of the cascade dryer 3.

[0043] Furthermore, the pre-drying system 6 can include a feeding device, for example a pump, for supplying the material from an external source to the screw press 7. A heat pump 9, which can be automatically regulated, is also located in the technical room 5.

[0044] Furthermore, the pre-drying system 6 includes a polymer preparation unit upstream of the screw press 7 for adding polymers to the material. The polymers added to the material by the polymer preparation unit cause the flocculation of solids within the material. Flocculation facilitates the separation of water from the solids. Furthermore, the consistency and handling of the dewatered material can be improved. More effective dewatering results in a lower water content in the material and thus an increase in the dry matter content.

[0045] According to the exemplary embodiment Fig. 1 and Fig. In the technical room 5, two air distribution ducts 10 are arranged. The air distribution ducts 10 run parallel to each other and are arranged horizontally next to each other.

[0046] In the drying chamber 2, an air supply duct 11 and an exhaust air duct 12 are arranged, wherein the air supply duct 11 and the exhaust air duct 12 are arranged on two opposite chamber walls on the narrow sides of the drying chamber 2.

[0047] Each air duct 10 is connected at its first end to the exhaust air duct 12 of the drying chamber 2 and at its second end to the supply air duct 11 of the drying chamber 2. This arrangement creates a recirculating air system, whereby the air is at least partially circulated between the exhaust air duct 11 and the supply air duct 11 of the drying chamber 2 via the air ducts 10. From the supply air duct 11, the air is transported via the drying chamber 2 to the exhaust air duct 12 and from the exhaust air duct 12 back to the supply air duct 11 via the air ducts 10.

[0048] A first air duct section 16 of the air distribution duct 10 runs in the intermediate floor 18 between the drying chamber 2 and the technical room 5, in particular in the area in the direction of air flow after the heating unit 14. The intermediate floor is located in the area below the pre-drying system 6.

[0049] A filter unit 13 designed as a horizontal cyclone is arranged in each air duct 10. The filter unit 13 can have a filter box and / or a dust box, each of which in particular has a quick-release fastener.

[0050] Furthermore, a heating unit 14, designed as a fan heater with integrated recirculation, is arranged in each air duct 10. The heating unit 14 is located downstream of the filter unit 13 in the direction of airflow.

[0051] Furthermore, the device 1 has an outlet chimney 15. The outlet chimney 15 branches off to the exhaust duct 12 of the drying chamber 2.

[0052] Each air duct 10 comprises a second air duct section 17, which is connected at its first end to the heater 14 and at its second end to the first air duct section 16 in the intermediate floor 18 between drying chamber 2 and technical room 5. The heater 14 can be opened by removing the second air duct section(s) 17.

[0053] A water storage tank 8 is located in the technical room 5. The water storage tank 8 can be part of the pre-drying system 6.

[0054] Technical room 5 and drying chamber 2 are each designed as containers. Technical room 5 is located on the top surface 19 of drying chamber 2. Therefore, the drying device requires very little installation space.

[0055] The technical room 5 has an access door 20 on its narrow side in the area of ​​the pre-drying system 6, which is accessible via a spiral staircase 21. The drying chamber 2 has two access doors 20 (not shown in the figures) on its long side. For example, all necessary connections, such as for water, especially heating water, and for the electrical system, can be located on the narrow side of the technical room 5.

[0056] The drying device 1 can have at least one control cabinet 23, wherein the control cabinet 23 is arranged in the technical room 5. Preferably, the control cabinet 23 is a control cabinet with a double door.

[0057] The drying device 1 may have one or more of the following sensors: water inlet sensor, outlet sensor, heat meter, sensor for sludge water inlet quantity with TS measurement, temperature and humidity sensor (especially external), sensors in the supply air duct and / or exhaust air duct, sensors for current consumption and / or electrical power, and / or sensors for outlet flow measurement. Reference symbol list 1 Device 2 drying chambers 3 cascade dryers 4 drying surface pairs 5 Technical Room 6 Pre-drying system 7 Drainage unit 8 water reservoirs 9 Heat pump 10 air ducts 11 Supply air duct 12 Exhaust duct 13 Filter unit 14 Heating unit 15 outlet chimney 16 first air duct section 17 second air duct section 18 intermediate floors 19 Top 20 Entrance door 21 Staircase 22 Management 23 Control cabinet

Claims

[1] Device (1) for drying material, in particular biomass, for example sewage sludge or wastewater, comprising at least one drying chamber (2), wherein a cascade dryer (3) with one or more drying surface pairs (4) is arranged in the drying chamber (2), wherein the cascade dryer (4) is provided for drying material from a first dry matter content, and at least one technical room (5), wherein a pre-drying plant (6) is arranged in the technical room (5) upstream of the drying chamber (2) from the perspective of the material to be dried, wherein the pre-drying plant (6) is provided for drying material with a second dry matter content that is lower than the first dry matter content, wherein the pre-drying system (6) is designed to be switchable on for pre-drying the material depending on the dry matter content of the material to be dried, so that if the dry matter content is equal to or greater than the first dry matter content, the material can be fed directly to the drying chamber (2) and if the dry matter content is less than the first dry matter content, it can be dried or is dried by means of the pre-drying system (6) up to a dry matter content that is equal to or greater than the first dry matter content. [2] Device (1) according to claim 1, characterized by that the pre-drying plant (6) includes at least one mechanical dewatering unit (7), in particular a screw press. [3] Device (1) according to claim 2, characterized by, that the pre-drying system (6) includes a feed device for supplying the material, for example from an external source, to the mechanical dewatering unit (7). [4] Device (1) according to any one of the preceding claims, characterized by , that the pre-drying plant (6) includes a polymer preparation unit for adding polymers to the material. [5] Device (1) according to claim 4, characterized by , that the polymer processing unit is located upstream of the mechanical dewatering unit (7). [6] Device (1) according to any one of the preceding claims, characterized by , that a heat pump (9) is located in the technical room (5). [7] Device (1) according to any one of the preceding claims, characterized by that one or more, preferably two, air ducts (10) are arranged in the technical room (5). [8] Device (1) according to any one of the preceding claims, characterized by, that in the drying chamber (2) an air supply duct (11) and an exhaust air duct (12) are arranged, wherein the air supply duct (11) and the exhaust air duct (12) are preferably arranged on two opposing chamber walls of the drying chamber (2). [9] Device (1) according to claims 7 and 8, characterized by , that each air duct (10) is connected at its first end to the exhaust duct (12) of the drying chamber (2) and at its second end to the supply air duct (11) of the drying chamber (2). [10] Device (1) according to claim 7 or 9, characterized by , that in each air duct (10) a filter device (13), in particular a cyclone, especially preferably a horizontal cyclone, is arranged. [11] Device (1) according to claim 7 or 9 or 10, characterized by , that a heating device (14), in particular a fan heater, preferably with integrated recirculation, is arranged in each air duct (10). [12] Device (1) according to claims 10 and 11, characterized by , that the heating device (14) is connected downstream of the filter device (13). [13] Device (1) according to claim 7 or any one of claims 9 to 12, characterized by , that a first air duct section (16) of the air duct (10) runs in the intermediate floor (18) between the drying chamber (2) and the technical room (5). [14] Device (1) according to any of the preceding claims, characterized by , that the technical room (5) is arranged or placed on the top (19) of the drying chamber (2). [15] Device (1) according to any of the preceding claims, characterized by , that their technical room (5) and / or drying chamber (2) are each designed as a container or in container construction.

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