Device for drying materials at low temperature and operation method

Abstract

The invention provides a low-temperature material drying device and an operation method, and relates to the technical field of low-temperature material drying, and the low-temperature material drying device comprises a heating device, a material supporting structure and a cooling device. The heating device is located below the materials, waste heat water is used for heating air to 35-65 DEG C, hot air rises to penetrate through the materials on the material supporting structure, and water on the surfaces of the materials is evaporated. The damp and hot air then enters the cooling system, and the cooling device enables moisture in the air to be condensed and discharged through a drainage pipe. And the dry and cold air is guided into the periphery of the snake-shaped heating water pipe again to form closed-loop circulation. The device adopts waste heat water as a heat source, saves energy, reduces carbon emission, and conforms to the national energy conservation and emission reduction policy; a multi-layer latticed material supporting structure and a closed-loop circulation system ensure uniform and efficient drying; fuel gas is not used, the carbon monoxide poisoning risk is eliminated, and intrinsic safety is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature material drying, and in particular to a device for drying materials at low temperatures. Background Art

[0002] Low-temperature drying of materials is a critical process in fields such as steelmaking, refractory production, plant seed preparation, and wood processing. For example, asphalt pellets tend to soften and stick together at high temperatures, plant seeds can become inactivated, and wood can easily deform and crack. Therefore, these materials must be dried at low temperatures to maintain their physical or biological activity.

[0003] Currently, common low-temperature drying technologies include microwave drying and vacuum drying. While microwave drying offers precise temperature control, it requires high equipment investment and consumes a lot of energy. While vacuum drying lowers the boiling point and achieves low-temperature dehydration, it is complex, requires high maintenance, and struggles to meet the demands of large-scale continuous production. Furthermore, both methods rely on external energy input, further increasing operating costs. This makes them less economical, especially for energy-intensive industries like steel.

[0004] At the same time, the steel production process generates a large amount of medium- and low-temperature waste heat, typically ranging from 50°C to 200°C. Due to its low quality, this waste heat is difficult to efficiently utilize using traditional recovery technologies, and most of it is directly discharged, resulting in significant energy waste.

[0005] Therefore, how to utilize the waste heat of steel to achieve low-cost, safe, and low-temperature drying has become a technical problem that needs to be solved urgently. Summary of the Invention

[0006] In response to the above technical problems, a device for low-temperature drying of materials is provided. The invention utilizes waste heat from the steel industry to heat the air below the materials to 35-65°C, and circulates evaporation and condensation of water to achieve low-temperature drying of the materials.

[0007] To achieve the above-mentioned object, the present invention provides a device for drying materials at low temperature, comprising a heating device, a material support structure, and a cooling device; The heating device is set below the material, using the waste heat from the steel industry to heat the air to 35~65℃, and a regulating valve is set at the upper water inlet; The material support structure is a multi-layered grid structure used to support the material, allowing hot air to pass from below and flow upward through the material; The cooling system includes a cooling device and a drain pipe. The cooling device is used to cool the hot and humid air so that the moisture in the air condenses on the surface of the cooling device. The drain pipe is installed under the cooling device to discharge the condensed moisture.

[0008] Furthermore, the heating device cooperates with the material support structure, and the heated air can rise and flow through the material. The material support structure is designed to allow air to pass through while supporting the material.

[0009] Furthermore, the cooling device is connected to the heating device through an air circulation system, and the dry cold air processed by the cooling system is introduced into the vicinity of the heating device and heated again for utilization, thereby forming a closed circulation system.

[0010] Furthermore, the heating device is a serpentine heating tube.

[0011] Furthermore, the closed-circuit circulation system comprises: Hot air rising channel, connecting the heating device and the material support structure; Hot and humid air introduction channel, connecting the material support structure and cooling system; Dry cold air return duct, connecting the cooling system and heating device.

[0012] Furthermore, the cooling device is a cooler with a coolant circulation, and the coolant can be recycled; The coolant inlet and outlet of the cooling device are respectively connected to the coolant circulation system to achieve continuous supply and reflux of the coolant.

[0013] Furthermore, a circulating fan is provided in the hot and humid air introduction channel.

[0014] The present invention also provides a method for low-temperature drying of materials, comprising the following steps: S1. Waste heat heating: The heating device utilizes waste heat generated in the steel industry to heat the air below the material layer to 35-65°C; S2. Water evaporation: The heated dry hot air flows vertically upward through the material layer, passes through the gaps between the materials and contacts the material surface. Since the water vapor partial pressure in the dry hot air is lower than the water partial pressure on the material surface, the water on the material surface evaporates, forming moist hot air. S3, moisture condensation: the hot and humid air enters the cooling system and is cooled to below the dew point by the cooling device. The moisture in the air condenses on the surface of the cooling device. The condensed water flows along the bottom surface of the cooling device to the lowest point and is discharged through the drain pipe. S4, circulation drying: the cooled dry cold air is led back to the surrounding of the heating device through the circulation channel, and is heated to 35-65°C by the heating device again, and steps S2-S3 are repeated until the moisture content of the material reaches the preset requirement.

[0015] Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art: 1. The present invention provides a device for low-temperature drying of materials. By utilizing waste heat water generated in the steel industry as a heat source, the air below the material is heated through a serpentine heating water pipe, thereby achieving efficient recovery and utilization of waste heat, reducing the consumption of traditional energy such as gas and electricity, and lowering the energy costs of enterprises.

[0016] 2. The present invention provides a device for low-temperature drying of materials, which adopts a serpentine heating water pipe to heat the air below the material, and cooperates with a multi-layer grid-shaped material support structure to enable the hot air to flow through the material evenly, thereby increasing the contact area between the material and the hot air, improving the drying efficiency, avoiding drying dead corners, and ensuring uniform drying of the material.

[0017] 3. The present invention provides a device for low-temperature drying of materials. The entire drying process does not use traditional energy such as gas, fundamentally eliminating the risk of carbon monoxide poisoning caused by the use of gas, and achieving inherent safety. At the same time, since waste heat is fully utilized, the demand for other high-carbon emission energy sources is reduced, which helps enterprises reduce carbon emissions and is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 This is a schematic structural diagram of a device for low-temperature drying materials according to the present invention; Figure 2 The present invention is a flowchart of a method for operating a device for low-temperature drying materials.

[0020] In the figure: 1. Heating device; 2. Material support structure; 3. Cooling system; 31. Cooling device; 32. Drain pipe; 4. Hot air rising channel; 5. Wet hot air inlet channel; 6. Dry cold air return channel; 7. Circulation fan; 8. Control valve. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0024] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as part of the specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary, rather than as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0025] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0026] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "above" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" another device or structure would then be positioned as "below" or "below" the other device or structure. Thus, the exemplary term "above" may include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0027] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0028] like Figure 1 As shown, the present invention provides a device for drying materials at low temperature, comprising a heating device 1, a material support structure 2, and a cooling device; The heating device 1 is a serpentine heating pipe, which is arranged below the material. It uses the waste heat from the steel industry to heat the air to 35-65°C. The heated air naturally rises along the grid gaps due to its reduced density and directly enters the material layer. No additional power is required to achieve air flow. A regulating valve 8 is provided at the upper water inlet to adjust the water inlet and control the heating temperature. The material support structure 2 is a multi-layer grid structure for carrying materials. The porosity is controlled at 30% to 50%. It takes into account both supporting materials and air circulation, allowing hot air to pass through from below and flow upwards through the materials. The hot air rises evenly along the grid gaps and flows through every surface of the material, solving the problem of material accumulation in existing drying methods that prevents internal drying. The cooling system 3 includes a cooling device 31 and a drain pipe 32. The cooling device 31 is installed at the end of the hot and humid air inlet channel 5 to cool the hot and humid air so that the moisture in the air condenses on the surface of the cooling device 31. The drain pipe 32 is installed obliquely below the cooling device 31 to discharge the condensed moisture.

[0029] Furthermore, the cooling device is connected to the heating device 1 through an air circulation, and the dry cold air treated by the cooling system 3 is introduced into the vicinity of the heating device 1 and heated again to form a closed circulation system. The dry cold air treated by the cooling device is connected to the surrounding space of the heating device 1 through a pipe. The dry cold air contacts the heating device 1 and is heated to 35-65°C by the waste heat of the steel again to form new dry hot air, which enters a cycle of heating, flowing through the material, cooling and dehumidifying, and returning to heating.

[0030] Furthermore, a material moisture content sensor is provided on the upper portion of the material support structure 2, which can monitor the moisture content of the material in real time.

[0031] Furthermore, the closed-circuit circulation system comprises: The hot air rising channel 4 connects the heating device 1 and the material support structure 2. The heated dry hot air rises through the channel, enters the grid gaps of the material support structure 2, and flows through the material; The hot and humid air introduction channel 5 connects the material support structure 2 and the cooling system 3, and the hot and humid air after flowing through the material is introduced into the cooling system 3 through the channel; The dry cold air return channel 6 connects the cooling system 3 and the heating device 1. The dry cold air after passing through the cooling system 3 returns to the surrounding of the heating device 1 through the channel and is heated again.

[0032] Furthermore, a circulating fan is provided in the hot and humid air introduction channel, which can enable the air in the channel to circulate quickly.

[0033] Furthermore, the three channels have clear division of labor. The hot air rising channel 4 guides the dry hot air accurately into the material layer, the humid hot air inlet channel 5 promptly guides away the water-containing air, and the dry cold air return channel 6 ensures the recycling of dry air, thereby improving the overall circulation efficiency.

[0034] Furthermore, the cooling device 31 is a cooler with a coolant circulation, and the coolant can be recycled; The coolant inlet and outlet of the cooling device 31 are respectively connected to the coolant circulation system to achieve continuous supply and reflux of the coolant. The cooling device 31 adopts a shell and tube cooler. The coolant is introduced into the shell and the hot and humid air is introduced into the tube. The coolant exchanges heat with the hot and humid air through the tube wall, reducing the air temperature to below the dew point and causing moisture to condense; the coolant inlet of the cooling device 31 is connected to the liquid supply pump of the circulation system to transport the coolant from the storage tank to the cooler; the coolant outlet is connected to the return liquid pipe of the circulation system to return the coolant after absorbing heat to the storage tank and reuse it after cooling in the cooling tower.

[0035] like Figure 2 As shown, the present invention also provides a method for low-temperature drying of materials, comprising the following steps: S1, waste heat heating: the waste heat generated in the steel industry is used by the heating device 1 to heat the air below the material layer to 35-65°C; S2. Water evaporation: The heated dry hot air flows vertically upward through the material layer, passes through the gaps between the materials and contacts the material surface. Since the water vapor partial pressure in the dry hot air is lower than the water partial pressure on the material surface, the water on the material surface evaporates, forming moist hot air. S3, moisture condensation: The hot and humid air enters the cooling system 3 and is cooled to below the dew point by the cooling device 31. The moisture in the air condenses on the surface of the cooling device 31. The condensed water flows along the bottom surface of the cooling device 31 to the lowest point and is discharged through the drain pipe 32. S4, circulating drying: the cooled dry cold air is guided back to the surrounding of the heating device 1 through the dry cold air return channel 6, and is heated to 35-65°C by the heating device 1 again. Steps S2-S3 are repeated until the moisture content of the material reaches the preset requirement.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for drying materials at low temperature, characterized in that: include: Heating device, material support structure, cooling device; The heating device is set below the material, using the waste heat from the steel industry to heat the air to 35~65℃, and a regulating valve is set at the upper water inlet; The material support structure is a multi-layered grid structure used to support the material, allowing hot air to pass from below and flow upward through the material; The cooling system includes a cooling device and a drain pipe. The cooling device is used to cool the hot and humid air so that the moisture in the air condenses on the surface of the cooling device. The drain pipe is installed under the cooling device to discharge the condensed moisture.

2. The device for low-temperature drying of materials according to claim 1, characterized in that: The heating device cooperates with the material support structure, and the heated air can rise and flow through the material. The material support structure is designed to allow air to pass through while supporting the material.

3. The device for low-temperature drying of materials according to claim 1, characterized in that: The cooling device is connected to the heating device through an air circulation system. The dry cold air processed by the cooling system is introduced into the vicinity of the heating device and is heated and utilized again, forming a closed circulation system.

4. The device for low-temperature drying of materials according to claim 1, characterized in that: The heating device is a serpentine heating tube.

5. The device for low-temperature drying of materials according to claim 3, characterized in that: The closed-circuit circulation system comprises: Hot air rising channel, connecting the heating device and the material support structure; Hot and humid air introduction channel, connecting the material support structure and cooling system; Dry cold air return duct, connecting the cooling system and heating device.

6. The device for low-temperature drying of materials according to claim 1, characterized in that: The cooling device is a cooler with a coolant circulation, and the coolant can be recycled; The coolant inlet and outlet of the cooling device are respectively connected to the coolant circulation system to achieve continuous supply and reflux of the coolant.

7. The device for low-temperature drying of materials according to claim 5, characterized in that: A circulating fan is provided in the hot and humid air introduction channel.

8. A method for operating a device for low-temperature drying materials, using the device according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Waste heat heating: The waste heat generated in the steel industry is used by the heating device to heat the air below the material layer to 35-65°C; S2, water evaporation: The heated dry hot air flows vertically upward through the material layer, passes through the gaps between the materials and contacts the surface of the materials, forming moist hot air; S3, moisture condensation: the hot and humid air enters the cooling system and is cooled to below the dew point by the cooling device. The moisture in the hot and humid air condenses on the surface of the cooling device. The condensed water flows along the bottom surface of the cooling device to the lowest point and is discharged through the drain pipe. S4, circulation drying: the cooled dry cold air is led back to the surrounding of the heating device through the circulation channel, and is heated to 35-65°C by the heating device again, and steps S2-S3 are repeated until the moisture content of the material reaches the preset requirement.

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