Vacuum drying condensation type sludge dryer

Abstract

According to the vacuum drying condensation type sludge dryer, a vacuum drying furnace containing sludge and drying the sludge and a water vapor condensation tank for cooling water vapor generated when the sludge is dried are connected through a connecting flow channel, the interior of the vacuum drying furnace and the interior of the water vapor condensation tank are both in a vacuum state through a vacuum pump, and the sludge is dried. Therefore, the structure is simple, cost is saved, and energy use efficiency can be improved. Moreover, the vacuum pump is not used for discharging a large amount of wet steam, so that the load of the vacuum pump can be minimized, and the vacuum pump not only has the advantage of being capable of using a small-capacity vacuum pump, but also can prevent the vacuum pump from malfunctioning due to the wet steam. Moreover, the heat pump is connected to the drying furnace heating part and the condensation tank cooling part, and the condensation heat and evaporation heat of the heat pump are used for heating and cooling, so that the energy use efficiency can be improved.

Description

Technical Field

[0001] The present invention relates to a vacuum drying and condensing sludge dryer, and more particularly to a vacuum drying and condensing sludge dryer configured to dry sludge at a low temperature in a vacuum drying furnace, condense water vapor generated during vacuum drying, and discharge it outward, so that the structure is simple and the sludge can be dried more efficiently. Background Art

[0002] Generally, in the process of treating sewage or wastewater in sewage treatment facilities or wastewater treatment facilities, precipitates, i.e., sludge, are generated. Since this sludge contains moisture, it is processed through a dehydration process of separating it from the moisture and a drying process of drying the dewatered sludge.

[0003] Existing drying processes mainly use a method of evaporating the moisture contained in the sludge by heating at a temperature of 100 degrees or higher. However, due to the need for a large amount of latent heat of evaporation, there is a problem of very high energy consumption.

[0004] [Prior Art Documents]

[0005] [Patent Documents]

[0006] Korean Registered Patent No. 10-1836464 Summary of the Invention

[0007] Technical Problem

[0008] An object of the present invention is to provide a vacuum drying and condensing sludge dryer with a simple structure and improved efficiency.

[0009] Technical Solution

[0010] The vacuum drying and condensing sludge dryer according to the present invention includes: a vacuum drying furnace configured to accommodate sludge and heat and dry it in a vacuum state; a drying furnace heating unit for heating the vacuum drying furnace; a water vapor condensation tank configured to introduce water vapor generated when drying sludge in the vacuum drying furnace, cool and condense it, and collect the generated condensed water; a condensation tank cooling unit for cooling the water vapor condensation tank; a connection flow path connecting the vacuum drying furnace and the water vapor condensation tank to direct the water vapor generated in the vacuum drying furnace to the water vapor condensation tank; and a vacuum pump connected to at least one of the vacuum drying furnace and the water vapor condensation tank to reduce the pressure in the vacuum drying furnace and the water vapor condensation tank so that the sludge can be dried at a low temperature in the vacuum drying furnace.

[0011] The vacuum pump further includes an intermediate valve connected to the water vapor condensation tank and configured to open and close the connection flow path, and a control unit for opening the intermediate valve to start the vacuum pump in a state where the connection flow path is open.

[0012] The drying furnace heating part includes a heating flow path that transfers the waste heat of exhaust gas or the heat source of warm water from the outside to the vacuum drying furnace.

[0013] The condensate tank cooling part includes a cooling flow path that transfers the cold source of outside air or cooling water from the outside to the water vapor condensate tank.

[0014] It further includes a heat pump, which includes a compressor, an evaporator, an expansion valve, and a condenser. The drying furnace heating part is heated by the condensation heat of the condenser, and the condensate tank cooling part is cooled by the evaporation heat of the evaporator.

[0015] The drying furnace heating part includes a heating flow path that connects the condenser and the vacuum drying furnace and transfers the heat source of the heat medium heated by heat exchange with the refrigerant flowing through the condenser to the vacuum drying furnace. The condensate tank cooling part includes a cooling flow path that connects the evaporator and the water vapor condensate tank and transfers the cold source of the cold medium cooled by heat exchange with the refrigerant flowing through the evaporator to the water vapor condensate tank.

[0016] The vacuum drying furnace includes a sludge input part configured to be able to open and close for inputting sludge, and a sludge discharge part configured to be able to open and close for discharging the dried sludge.

[0017] The water vapor condensate tank includes a condensate water discharge part configured to be able to open and close for discharging the collected condensate water.

[0018] When inputting sludge, the control part opens the sludge input part. When the input of sludge is completed, the sludge input part is sealed, the intermediate valve is opened, and the vacuum pump is started. After reducing the pressure in the vacuum drying furnace and the water vapor condensate tank, the operation of the vacuum pump is aborted, and the drying furnace heating part and the condensate tank cooling part are started.

[0019] After the drying of sludge is completed, the control part closes the intermediate valve to only open the sludge discharge part while maintaining the vacuum state of the water vapor condensate tank.

[0020] Technical effects

[0021] According to the vacuum drying and condensing type sludge dryer of the present invention, the vacuum drying furnace that accommodates and dries sludge and the water vapor condensate tank that condenses the water vapor generated during the drying of sludge are connected by a connecting flow path. The pressure inside the vacuum drying furnace and the water vapor condensate tank is reduced by using a vacuum pump, so that the sludge can be dried at a lower temperature in the vacuum drying furnace, thereby having a simple structure, reducing costs, and being able to improve the energy use efficiency.

[0022] Moreover, a vacuum pump is not used to discharge a large amount of wet steam, thereby minimizing the load on the vacuum pump. Therefore, it has the advantage of being able to use a small-capacity vacuum pump and can also prevent failures of the vacuum pump caused by wet steam.

[0023] In addition, a heat pump is connected to the drying furnace heating section and the condensation tank cooling section, and the condensation heat and evaporation heat of the heat pump are used for heating and cooling, thereby improving the energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic configuration diagram of a vacuum drying and condensing sludge dryer according to an embodiment of the present invention;

[0025] Figure 2 is a schematic configuration diagram of a vacuum drying and condensing sludge dryer according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0027] Figure 1 is a schematic configuration diagram of a vacuum drying and condensing sludge dryer according to an embodiment of the present invention.

[0028] Refer to Figure 1 , a vacuum drying and condensing sludge dryer according to an embodiment of the present invention is a device for drying sheet-like sludge discharged from a dehydrator (not shown) of a sludge treatment device, and includes a vacuum drying furnace 10, a water vapor condensation tank 20, a connecting flow path 30, a drying furnace heating section 40, a condensation tank cooling section 50, a vacuum pump 60, and a control section (not shown).

[0029] The vacuum drying furnace 10 is formed as a vacuum chamber for accommodating the input sludge and heating and drying it in a vacuum state. The upper part of the vacuum drying furnace 10 has a sludge input section 11 that can be opened and closed to input sludge, and the lower part has a sludge discharge section 12 that can be opened and closed to discharge the sludge that has been dried inside to the outside. The sludge input section 11 and the sludge discharge section 12 each have an opening and closing member.

[0030] The water vapor condensation tank 20 is connected to the vacuum drying furnace 10 through the connecting flow path 30. The water vapor condensation tank 20 is formed as a chamber for flowing in the water vapor discharged from the vacuum drying furnace 10 through the connecting flow path 30, cooling and condensing the flowing water vapor, and collecting the condensed water. The lower part of the water vapor condensation tank 20 has a condensed water discharge section 22 that can be opened and closed to discharge the collected condensed water to the outside. A condensed water discharge valve 23 is provided in the condensed water discharge section 22. A condensed water discharge pump (not shown) may also be provided in the condensed water discharge section 22.

[0031] The connecting flow channel 30 is an intermediate flow channel connecting the upper part of the vacuum drying furnace 10 and the upper part of the water vapor condensation tank 20. The connecting flow channel 30 is formed to guide the water vapor generated from the sludge when heating the vacuum drying furnace 10 to the water vapor condensation tank 20. Moreover, the connecting flow channel 30 can function as a vacuum suction flow channel that forms a vacuum state for both the vacuum drying furnace 10 and the water vapor condensation tank 20 simultaneously when the vacuum pump 60 operates. In this embodiment, an example is described where the connecting flow channel 30 is formed such that at least a part thereof slopes upward to facilitate the movement of water vapor. An intermediate valve 35 is provided on the connecting flow channel 30.

[0032] The drying furnace heating part 40 is a heating device for heating the vacuum drying furnace 10. In this embodiment, an example is described where the drying furnace heating part 40 is formed as a heating flow channel that guides the heat medium of the waste heat recovered from the exhaust gas outside to the vacuum drying furnace 10. Among them, the exhaust gas can be various types such as the exhaust gas of the sludge treatment device or the exhaust gas of another combustion facility, etc. However, it is not limited to this. The drying furnace heating part 40 can also use the high-temperature water discharged from a boiler, etc., and can also use another heater. That is, regarding the drying furnace heating part 40, as long as it is a heating device that can heat the inside of the vacuum drying furnace 10 at a preset evaporation temperature, it can be applied in various forms with changes.

[0033] The condensation tank cooling part 50 is a cooling device for cooling the water vapor condensation tank 20. In this embodiment, an example is described where the condensation tank cooling part 50 is formed as a cooling flow channel that guides the cold medium of the cold air source recovered from the outside to the water vapor condensation tank 20. However, it is not limited to this. The condensation tank cooling part 50 can also be configured to recover the cold source of cooling water. That is, regarding the condensation tank cooling part 50, as long as it is a cooling device that can cool the inside of the condensation tank cooling part 50 at a preset condensation temperature, it can be applied in various forms with changes.

[0034] The vacuum pump 60 is connected to at least one of the vacuum drying furnace 10 and the water vapor condensation tank 20. In this embodiment, an example is described where the vacuum pump 60 is only connected to the water vapor condensation tank 20. However, it is not limited to this. The vacuum pump 60 can also be only connected to the vacuum drying furnace 10, and of course, it can also be respectively connected to the vacuum drying furnace 10 and the water vapor condensation tank 20.

[0035] The vacuum pump 60 is connected to the water vapor condensation tank 20. The vacuum pump 60 not only sucks in the internal air of the water vapor condensation tank 20, but also sucks in the internal air of the vacuum drying furnace 10 through the connecting flow path 30 to reduce the pressures of the vacuum drying furnace 10 and the water vapor condensation tank 20. Hereinafter, in this embodiment, an example in which the vacuum pump 60 forms a vacuum state for both the vacuum drying furnace 10 and the water vapor condensation tank 20 will be described.

[0036] A malodor treatment device (not shown) for purifying the malodor generated inside may be disposed at the rear end of the vacuum pump 60.

[0037] The control unit (not shown) controls the operations of the intermediate valve 35 and the vacuum pump 60 according to the operation of the sludge dryer.

[0038] The operation of the vacuum drying and condensing type sludge dryer according to an embodiment of the present invention configured as described above will be described below.

[0039] Regarding the operation of the vacuum drying and condensing type sludge dryer according to an embodiment of the present invention, it is configured such that a sludge input process, a vacuum process, a drying and condensing process, and a sludge discharge process form a cycle.

[0040] First, when performing the sludge input process, the control unit (not shown) opens the sludge input unit 11 to input sludge through the sludge input unit 11. The opening and closing of the sludge input unit 11 will be described by taking the example of being automatically performed according to the control of the control unit (not shown), but it is not limited thereto, and it may also be performed by an operator.

[0041] After completing the sludge input process, the control unit (not shown) seals the sludge input unit 11.

[0042] When performing the vacuum process, the control unit (not shown) opens the intermediate valve 35 and starts the vacuum pump 60. After starting the vacuum pump 60, all the air inside the vacuum drying furnace 10, the connecting flow path 30, and the water vapor condensation tank 20 is sucked by the vacuum pump 60 and discharged to the outside, so that the vacuum drying furnace 10, the connecting flow path 30, and the water vapor condensation tank 20 all become a vacuum state together.

[0043] In this embodiment, since the vacuum drying furnace 10 and the water vapor condensation tank 20 are connected through the connecting flow path 30, a vacuum state can be formed only by the single vacuum pump 60 disposed in the water vapor condensation tank 20.

[0044] After completing the vacuum process, the control unit (not shown) stops the operation of the vacuum pump 60.

[0045] When performing the drying and condensation processes, the control unit (not shown) activates the drying furnace heating unit 40 and the condensation tank cooling unit 50. Here, the intermediate valve 35 remains open.

[0046] After heating the vacuum drying furnace 10 by the drying furnace heating unit 40, water vapor is evaporated from the sludge inside the vacuum drying furnace 10 while the sludge is dried.

[0047] The water vapor evaporated in the vacuum drying furnace 10 flows into the water vapor condensation tank 20 through the connecting flow path 30. When the water vapor condensation tank 20 is cooled by the condensation tank cooling unit 50, the water vapor flowing into the water vapor condensation tank 20 is cooled and condensed to generate condensed water, and the generated condensed water is collected at the lower part of the water vapor condensation tank 20.

[0048] The condensed water collected at the lower part of the water vapor condensation tank 20 is periodically or continuously discharged to the outside, so that the vacuum state of the water vapor condensation tank 20 can be maintained to the maximum extent.

[0049] A pressure sensor is provided inside the water vapor condensation tank 20, and when the internal pressure of the water vapor condensation tank 20 changes, the vacuum pump 60 can be further activated.

[0050] When the vacuum pump 60 is further activated, the vacuum pump 60 is not in a state of inhaling a large amount of moisture containing a large amount of water vapor, so no failure caused by water vapor will occur.

[0051] After the drying of the sludge is completed, the control unit (not shown) closes the intermediate valve 35.

[0052] When performing the sludge discharge process, the control unit (not shown) opens the sludge discharge unit 12 to discharge the dried sludge to the outside.

[0053] During the discharge of the sludge, the vacuum state of the water vapor condensation tank 20 can be maintained to the maximum extent by closing the intermediate valve 35. Therefore, the work that the vacuum pump 60 needs to perform in the next cycle can be minimized.

[0054] As described above, the sludge dryer according to an embodiment of the present invention operates in a semi-batch mode in which a certain amount of sludge is input, dried, and then discharged. That is, the input and discharge of the sludge are intermittent, and the drying of the sludge and the condensation of water vapor are continuously performed.

[0055] Moreover, the sludge dryer according to the present invention can improve the energy utilization efficiency by using waste heat when heating the vacuum drying furnace 10.

[0056] Moreover, since the present invention does not continuously discharge a large amount of water vapor using a vacuum pump, it is possible to prevent malfunctions that occur when the vacuum pump 60 is exposed to a large amount of water vapor.

[0057] Moreover, in the vacuum drying furnace 10, the evaporation of water vapor causes an increase in volume, but it is condensed in the water vapor condensation tank 20 and the volume decreases again. In the present invention, the vacuum pump 60 does not extract the water vapor with an increased volume, so the advantage is that a small-capacity vacuum pump 60 can be used.

[0058] Moreover, when discharging sludge, the intermediate valve 35 is closed to maximize the vacuum in the water vapor condensation tank 20, so it is possible to minimize the work done by the vacuum pump 60 during the vacuum process of the next cycle after one cycle ends.

[0059] Moreover, the odor generated in the vacuum drying furnace 10 and the water vapor condensation tank 20 can be discharged when the vacuum pump 60 is started during the vacuum process of the next cycle after one cycle ends. An odor treatment device can be arranged at the rear end of the vacuum pump 60.

[0060] In addition, Figure 2 is a configuration diagram briefly showing a vacuum drying and condensing type sludge dryer according to another embodiment of the present invention.

[0061] See Figure 2 , the vacuum drying and condensing type sludge dryer according to another embodiment of the present invention further includes a heat pump 100 connected between the drying furnace heating unit 140 and the condensation tank cooling unit 150, including a compressor 101, a condenser 102, an expansion valve 103, an evaporator 104 and a refrigerant flow path 105. Different from the one embodiment in using the condensation heat and evaporation heat of the heat pump 100 in the drying furnace heating unit 140 and the condensation tank cooling unit 150, the remaining configurations and functions are similar, and the detailed description of the similar content is omitted below, and only the different configurations will be described in detail.

[0062] The drying furnace heating unit 140 is a heating flow path that connects the condenser 102 and the vacuum drying furnace 10 and is used to supply the heat source of the heat medium heated by heat exchange with the refrigerant flowing through the condenser 102 to the vacuum drying furnace 10. That is, the drying furnace heating unit 140 is heated by the condensation heat of the condenser 102 of the heat pump 100.

[0063] The condensation tank cooling unit 150 is a cooling flow path that connects the evaporator 104 and the water vapor condensation tank 20 and is used to transfer the cold source of the cold medium cooled by heat exchange with the refrigerant flowing through the evaporator 104 to the water vapor condensation tank 20. That is, the condensation tank cooling unit 150 is cooled by the evaporation heat of the evaporator 104 of the heat pump 100.

[0064] As described above, the sludge dryer according to another embodiment of the present invention uses the evaporation heat and condensation heat of the heat pump 100, and thus can improve the energy use efficiency.

[0065] The present invention has been described with reference to the embodiments shown in the drawings, but this is merely exemplary. Those of ordinary skill in the art should understand that various modifications and equivalent other embodiments can be achieved therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the appended claims.

Claims

1. A vacuum drying and condensing sludge dryer, comprising: A vacuum drying furnace, configured to accommodate sludge and heat and dry it in a vacuum state; A drying furnace heating unit, configured to heat the vacuum drying furnace; A steam condensation tank, configured to introduce the steam generated when drying sludge in the vacuum drying furnace, cool and condense it, and collect the generated condensed water; A condensation tank cooling unit, configured to cool the steam condensation tank; A connecting flow path, connecting the vacuum drying furnace and the steam condensation tank, and guiding the steam generated in the vacuum drying furnace to the steam condensation tank; And A vacuum pump, connected to at least one of the vacuum drying furnace and the steam condensation tank, configured to reduce the pressure of the vacuum drying furnace and the steam condensation tank, so that the sludge can be dried at a low temperature in the vacuum drying furnace.

2. The vacuum drying and condensing sludge dryer according to claim 1, wherein: The vacuum pump is connected to the steam condensation tank. The vacuum drying and condensing type sludge dryer further includes: An intermediate valve, configured to open and close the connecting flow path; and A control unit, configured to open the intermediate valve to start the vacuum pump in a state where the connecting flow path is open.

3. The vacuum drying and condensing sludge dryer according to claim 1, wherein, The drying furnace heating unit includes: A heating flow path, configured to transfer the waste heat of exhaust gas or the heat source of warm water from the outside to the vacuum drying furnace.

4. The vacuum drying and condensing sludge dryer according to claim 1, wherein, The condensation tank cooling unit includes: A cooling flow path, configured to transfer the cold source of outside air or cooling water from the outside to the steam condensation tank.

5. The vacuum drying and condensing sludge dryer according to claim 1, wherein, It further includes: A heat pump, including a compressor, an evaporator, an expansion valve, and a condenser. The drying furnace heating unit is heated by the condensation heat of the condenser. The condensation tank cooling unit is cooled by the evaporation heat of the evaporator.

6. The vacuum drying and condensing sludge dryer according to claim 5, wherein: The drying furnace heating unit includes: A heating flow path, connecting the condenser and the vacuum drying furnace, and transferring the heat source of the heat medium heated by heat exchange with the refrigerant flowing through the condenser to the vacuum drying furnace. The condensation tank cooling unit includes: A cooling flow path, connecting the evaporator and the steam condensation tank, and transferring the cold source of the cold medium cooled by heat exchange with the refrigerant flowing through the evaporator to the steam condensation tank.

7. The vacuum drying and condensing sludge dryer according to claim 2, wherein, The vacuum drying furnace includes: A sludge input part, configured to be openable and closable to input sludge; and A sludge discharge part, configured to be openable and closable to discharge the dried sludge.

8. The vacuum drying and condensing sludge dryer according to claim 7, wherein, The steam condensation tank includes: A condensed water discharge part, configured to be openable and closable to discharge the collected condensed water.

9. The vacuum drying and condensing sludge dryer according to claim 8, wherein: The control unit opens the sludge input part when inputting sludge. When the input of sludge is completed, the sludge input part is sealed, and the intermediate valve is opened and the vacuum pump is started. After reducing the pressure of the vacuum drying furnace and the steam condensation tank, the operation of the vacuum pump is aborted, and the drying furnace heating unit and the condensation tank cooling unit are started.

10. The vacuum drying and condensing sludge dryer according to claim 9, wherein: When the drying of sludge is completed, the control unit closes the intermediate valve to keep the vacuum state of the steam condensation tank and only opens the sludge discharge part.

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