KR101481773B1 - Apparatus for drying sewage sludge and method for manufacturing solid fuel with sewage sludge - Google Patents

Abstract

The present invention relates to an apparatus for drying sewage sludge and to a manufacturing method of solid fuel with sewage sludge. The apparatus for drying sewage sludge comprises a hopper for inputting sewage sludge; a first drying chamber connected to the hopper and having an accommodation space; a first conveying means installed within the first drying chamber and conveying the sewage sludge to the rear end of the first drying chamber; heat medium oil arranged in the lower space of the first drying chamber; and a first heater for heating the heat medium oil. The sewage sludge is dried by removing moisture by heat transferred by the heated heat medium oil within the first drying chamber. According to the composition, the sewage sludge is dried by exchanging heat with the heat medium oil heated while being conveyed through the inside of the drying chamber, thereby rapidly and efficiently drying sewage sludge containing a high content of water at a low cost, and manufacturing solid fuel with the dried sewage sludge.

Description

Technical Field [0001] The present invention relates to a sewage sludge drying apparatus and a sewage sludge solid fuel producing method,

The present invention relates to a sewage sludge drying apparatus and a sewage sludge solid fueling method.

Conventionally, sludge generated mainly in a sewage treatment process has been subjected to marine dumping or landfilling. However, marine dumping is prohibited in order to protect the environment, landfill sites are limited, and disposal is becoming increasingly difficult.

So, in order to extend the life of the landfill, the sludge is incinerated to reduce the volume of the sludge so that the ash is buried or dried sludge is used for soil improvement.

In the case of general sewage sludge, the liquid content is high up to a water content of about 100 to 90%, and the viscosity is low. When the water content is about 90 to 85%, the slurry is in a liquid state although its viscosity is high and its fluidity is bad. When the water content is about 85 to 75%, the fluidity disappears in the paste state, but when the temperature is raised, it becomes closer to the slurry state. Further, when the water content is 75% or less, it becomes a cake state showing a state of a solid, and it becomes easy to granulate. When the water content is 30% or less, the shape becomes close to powder.

It is general that the dehydrated sludge or the like has a moisture content as high as 85% to 75% and is inconvenient to handle, so that it is subjected to a drying treatment so that the water content becomes 40% or less. Such a drier for drying sludge is generally used as an indirect heat dryer in which steam is filled in an air stream dryer or a steam jacket for blowing hot air and dried, and the water in the sludge is evaporated and dried using latent heat of steam.

In these dryers, the sludge to be dried is small granulated, and the larger the surface area, the more efficient the heat transfer. When the moisture content of the dried sludge is high, the sludge is hardly granulated so that only the surface of the sludge is dried and the inside of the sludge is not evaporated and the inside of the dryer is closed with the sludge, have.

Generally, the surplus sludge generated in the sewage treatment has a water content of about 99%, and the sludge is mechanically squeezed with a sludge dehydrator to bring the water content to about 80%, and then the sludge is added to the drier to perform the drying treatment.

However, since a meal of a general household becomes high-calorie, the concentration of the organic matter of the excess sludge generated in the sewage treatment increases year by year, so that the dewatering performance is lowered and the water content of the dewatered cake tends to increase. As a result, even if the dewatering cake is directly put into the dryer, stable operation can not be performed.

In this case, the surface of the object to be dried is covered with an incineration material having a low moisture content or dried sludge, or is applied to the entire surface to prevent the object to be dried from being attached to the inside of the apparatus.

In addition, a portion of the dried dried material is mixed with the dried sludge at the input side of the drier, thereby lowering the viscosity of the dried object to improve dispersibility.

However, this method has a problem in that not only the processing capability of the dryer is lowered but also the equipment is complicated due to facilities for returning a part of the discharged dried material to the input side of the dryer, thereby increasing the facility cost.

Korean Patent Application No. 10-1999-0013884

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sewage sludge drying apparatus and a sewage sludge solid fuel conversion method capable of rapidly and efficiently drying a sludge having a high water content at a low cost and solidifying it into solid fuel .

According to an aspect of the present invention, there is provided a sewage sludge drying apparatus including: a hopper into which sewage sludge is introduced; A first drying furnace connected to the hopper and having a receiving space; A first conveying means installed in the first drying furnace and feeding the sewage sludge to a rear end of the first drying furnace; A heating medium oil disposed in a lower space of the first drying furnace; A first heater for heating the thermal oil; And the sewage sludge introduced into the hopper is dried by removing moisture by heat transfer by the heated heat medium oil in the first drying furnace.

A fan disposed above the first drying furnace or above the hopper to discharge steam generated in the first drying furnace to the outside; .

A crusher connected to the rear end of the first drying furnace to crush dried sewage sludge; A second drying furnace connected to the crusher and having a receiving space; Second conveying means for conveying the sewage sludge fed into the second drying furnace to the rear end of the second drying furnace; A heating medium oil disposed in a lower space of the second drying furnace; A second heater for heating the heat medium oil; And the sewage sludge introduced into the second drying furnace is dried by removing moisture secondarily by heat transfer by the heating medium oil in the second drying furnace.

A fine pulverizer connected to the rear end of the second drying furnace to pulverize the dried sewage sludge; A solid-liquid separator connected to a lower portion of the fine pulverizer and separating the liquid from the pulverized sewage sludge; A pellet molding machine connected to the solid-liquid separator for molding the sewage sludge into pellets; .

A mesh net positioned below the first drying path and capable of passing heat medium oil but not passing sewage sludge; .

According to another aspect of the present invention, there is provided a sewage sludge drying apparatus comprising: a hopper into which sewage sludge is introduced; A first drying furnace connected to a lower portion of the hopper and having a receiving space; A heating medium oil disposed in a lower space of the first drying furnace; A first heater for heating the thermal oil; And the sewage sludge fed into the first drying furnace is dried by removing moisture by heat transfer by the heating medium oil in the first drying furnace.

According to another aspect of the present invention, there is provided a method for converting sewage sludge into solid fuel, comprising the steps of: injecting sewage sludge into a first drying furnace; Transferring the sewage sludge to a rear end of the first drying furnace; Removing water from the sewage sludge by heat transfer by heated thermal oil disposed in a lower space of the first drying furnace during transportation of the sewage sludge; Crushing the water-removed sewage sludge in a crusher; Molding the pulverized sewage sludge into a pellet shape; .

According to the present invention, since the sewage sludge is transported through the inside of the drying furnace and dried by heat exchange with the heated heating oil, the sewage sludge drying device capable of drying the high water content sludge quickly and efficiently at a low cost, A solid fuel conversion method can be provided.

1 is a view showing the construction of a sewage sludge drying apparatus according to an embodiment of the present invention.
Fig. 2 is a view showing the detailed structure of the front end portion of the sewage sludge drying apparatus of Fig. 1;
3 is a detailed view showing a rear end configuration of the sewage sludge drying apparatus of FIG.
4 is a block diagram illustrating a sewage sludge solidification fueling method according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. The same reference numerals in the drawings denote like elements throughout the drawings.

1 is a view showing the construction of a sewage sludge drying apparatus according to an embodiment of the present invention. Fig. 2 is a view showing the detailed structure of the front end portion of the sewage sludge drying apparatus of Fig. 1; 3 is a detailed view showing a rear end configuration of the sewage sludge drying apparatus of FIG.

The sewage sludge drying apparatus 100 includes a hopper 110, a first drying furnace 120, a first conveying means 130, a heating medium oil 140, a first heater 141, a crusher 145, A second conveying unit 160, a fine pulverizer 173, a second heater 166, a solid-liquid separator 180, a pellet forming unit 190, and the like.

The hopper 110 has a large inlet so that sewage sludge (hereinafter, sludge) can be injected. The width of the hopper 110 generally decreases toward the bottom, but is not limited to such a shape as long as the sludge 1 can be fed and fed to the bottom. The hopper 110 may be provided with a lid 111.

A roller portion 112 may be disposed under the hopper 110. The roller unit 112 is disposed in the hopper 110 and forms a sludge having a predetermined thickness to be fed to the first drying furnace 120. The roller unit 112 is formed of a pair of rollers, and the sludge can be transferred between the rollers to have a constant thickness.

The first drying furnace 120 is connected to the hopper 110 and has a receiving space therein. The first drying furnace 120 is directly connected to the lower portion of the hopper 110 so that the sludge introduced into the hopper 110 can be directly dropped to the first drying furnace 120 through the roller portion 112.

The first conveying means 130 is installed inside the first drying furnace 120 and transfers the sludge 1 to the rear end of the first drying furnace 120. The first conveying means 130 may be constituted by a conveying screw. The first conveying means 130 may have a structure in which the shaft 131 is rotated by the motor 132 to transfer the sludge to the rear end portion by the first drying furnace 120.

The heating medium oil 140 is disposed in the lower space of the first drying furnace 120 and is heated by the first heater 141. For example, a part of the first drying furnace 120 may extend downward to have a receiving space, and the receiving space may receive the heating medium oil 140. The thermal oil 140 may be a waste cooking oil, a soybean oil, a perilla oil, a heavy oil, a light oil, or the like, preferably a waste cooking oil. The boiling point of the thermal oil 140 may be 110 ° C or higher, preferably 175 to 220 ° C. The temperature of the heating medium oil 140 is preferably 175 DEG C or higher in order to quickly vaporize the moisture contained in the sludge. When the temperature of the heating medium oil 140 is 220 DEG C or higher, the drying efficiency of the sludge It does not rise sufficiently and becomes uneconomical.

The sludge introduced into the hopper 110 passes over the heated heating medium oil 140 while being conveyed by the first conveying means 130 in the first drying furnace 120. Accordingly, the water contained in the sludge is directly vaporized by the heat transfer by the heating medium oil 140 heated to about 200 ° C. The thermal oil 140 penetrates not only the surface of the agglomerated sludge but also the inside of the sludge so that the moisture in the interior can be quickly vaporized. The sludge that has passed through the thermal oil (140) may be crispy as it is fried in oil. Accordingly, there is no problem that the sludge is conventionally attached to the apparatus by the viscosity.

Conventionally, the method of drying the sludge by steam has a problem in that a considerable amount of moisture is contained in the sludge even after drying because the drying is costly and only the surface is dried. Further, when a step of covering the surface of the dried sludge with a low moisture content incineration ash or dried sludge is added in order to prevent the sludge having viscosity from being adhered to the apparatus, the apparatus becomes complicated and the facility cost is increased.

On the contrary, the sludge drying method using the thermal oil 140 of the present invention makes it possible to completely remove moisture contained in the sludge at a low cost.

The water vapor generated in the first drying furnace 120 can be discharged to the outside by the fan 115 at the upper part of the hopper 110. The fan 115 may be installed on the upper portion of the first drying furnace 120.

The mesh net 142 is located below the first drying furnace 120 and allows the passage of the heat medium oil 140 but not the sludge. Accordingly, the heat medium oil 140 that transfers heat to the sludge can be dropped through the mesh net 142 to control the heat medium oil 165 contained in the dried sludge. The mesh network 142 may be positioned below the transport screw 130. The arrangement of the first conveying means 130, the heating medium oil 140, and the mesh net 142 can be appropriately selected or changed by those skilled in the art as required.

The sludge exiting the first drying furnace 120 passes through the crusher 145. The crusher 145 is connected to the rear end of the first drying furnace 120 to finely crush the dried sludge. The sludge that has exited the first drying furnace 120 can be removed from the sludge by the heat transfer by the thermal oil 140, so that the water content can be less than about 20%.

The sludge pulverized in the pulverizer 145 is introduced into the hopper 146 and is placed on the conveyor belt 147 connected to the lower portion of the hopper 146 and can be conveyed to the second drying furnace 150.

The second drying furnace 150 has a receiving space and is connected to the crusher 145 to dry secondarily the moisture contained in the crushed sludge. The second conveying means 160 conveys the sludge introduced into the second drying furnace 150 to the rear end of the second drying furnace 150. The second conveying means 160 may be composed of rollers 161 and 163 and a conveyor belt 162. The conveyor belt 162 may be in the form of a mesh net.

The heating medium oil 165 is disposed in the lower space of the second drying furnace 150 and is heated by the second heater 166. The heating medium oil 165 may be accommodated in the container 164 disposed below the second drying furnace 150. The conveyor belt 162 is rotated by the rollers 161 and 163 and passes through the container 164 containing the thermal oil 165. The sludge on the conveyor belt 162 is conveyed by the heat transfer oil 165 And then dried to remove moisture. Thereafter, the sludge is conveyed along the upwardly inclined conveyor belt 162, and the heat medium oil contained in the sludge can be discharged to the lower portion of the mesh-type conveyor belt 162. The sludge that has passed through the thermal oil 165 is removed from the sludge and the water content becomes almost 0%.

The steam generated in the second drying furnace 150 may be discharged to the outside by the fan 155 at the upper part of the second drying furnace 150.

The sludge transferred to the rear end of the second drying furnace 150 after the moisture is removed is dropped from the roller 163 into the receiving portion 171 and is conveyed backward by the conveying screw 172 in the receiving portion 171 3 to the ground). The sludge conveyed by the conveyance screw 172 falls into the fine pulverizer 173 and can be finely crushed while passing through the fine pulverizer 173.

The sludge pulverized in the fine pulverizer 173 passes through the solid-liquid separator 180. The solid-liquid separator 180 is connected to the lower portion of the fine pulverizer 173 to separate the liquid (thermal oil) from the sludge, for example, in the form of a centrifugal separator. Even if the liquid is separated from the sludge, a certain amount of the heat medium oil may be contained in the sludge.

The sludge in which the liquid has been separated in the solid-liquid separator 180 moves to the pellet molding machine 190. The pellet molding machine 190 is connected to the solid-liquid separator 180 to mold the solid component sludge into a pellet shape. Sludge formed in pellet form can be used as fuel in thermal power plants and the like.

The sludge drying apparatus of the present invention described above can remove moisture from heat transfer due to contact with the heating medium oils 140 and 165 while passing through the first drying furnace 120 and the second drying furnace 150, The sludge can be dried until the water content reaches approximately 0%.

Hereinafter, the sewage sludge solidification method of the present invention will be described with reference to FIGS. 1 to 4. FIG. 4 is a block diagram illustrating a sewage sludge solidification fueling method according to an embodiment of the present invention.

First, the sludge is introduced into the first drying furnace 120 (S10).

Next, the sludge is transferred to the rear end of the first drying furnace 120 (S20). During the transfer of the sludge, moisture of the sludge is firstly removed by heat transfer by the heated thermal oil 140 disposed in the lower space of the first drying furnace 120 (S30).

Next, the water-removed sludge is pulverized in the pulverizer 145 (S40).

Next, the pulverized sludge is introduced into the second drying furnace 150 (S50).

Next, the sludge is transferred in the second drying furnace 150 (S60). During the transfer of the sludge, moisture of the sludge is removed by heat transfer by the heated thermal oil 140 located in the lower part of the second drying furnace 150 (S70).

Next, the sludge from which moisture has been removed is pulverized in the fine pulverizer 173 (S80).

Next, the pulverized sludge is separated in the solid-liquid separator 180 (S90).

Next, the sludge is molded into a pellet shape from the pellet molding machine 190 (S100).

The sewage sludge solidification method described above may include all of the contents described above with respect to the sludge drying apparatus 100.

According to the sewage sludge solid fueling method described above, the sludge can be dried quickly to a moisture content of about 0% at a low cost. Since the sludge contains a predetermined amount of thermal oil, it is molded into pellets and used as fuel for thermal power plants . This makes it possible to effectively treat the sludge at low cost in the reality that marine dumping is prohibited and the processing cost of sludge becomes a problem.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention will be.

100: sewage sludge drying device
110: Hopper
112: roller portion
120: First drying furnace
130: first conveying means
140: heat medium oil
141: first heater
145: crusher
150: Second drying furnace
160: second conveying means
165: Thermal oil
166: second heater
173: fine grinder
180: Solid-liquid separator
190: Pellet molding machine

Claims (7)

In the sewage sludge drying apparatus,
A hopper 110 into which sewage sludge is introduced;
A first drying furnace (120) connected to the hopper (110) and having a receiving space;
A first conveying means 130 installed in the first drying furnace 120 for conveying sewage sludge to a rear end of the first drying furnace 120;
A heating medium oil disposed in a lower space of the first drying furnace 120;
A first heater for heating the thermal oil;
A mesh network 142 positioned below the first conveying means 130 and capable of passing heat medium but not sewage sludge;
A crusher 145 connected to the rear end of the first drying furnace 120 to crush dried sewage sludge;
A second drying furnace 150 connected to the crusher 145 and having a receiving space;
A second drying furnace 150 for conveying sewage sludge into the second drying furnace 150 including the rollers 161 and 163 and the mesh network type conveyor belt 162, Conveying means;
A heating medium oil accommodated in a container 164 disposed in a lower space of the second drying furnace 150;
A second heater for heating the heat medium oil;
A fine pulverizer (173) connected to the rear end of the second drying furnace (150) for pulverizing the dried sewage sludge;
A solid-liquid separator (180) connected to a lower portion of the fine pulverizer (173) and separating the liquid from the pulverized sewage sludge;
A pellet molding machine 190 connected to the solid-liquid separator 180 for molding the sewage sludge into a pellet shape;
Lt; / RTI >
The sewage sludge introduced into the hopper 110 is dried by removing heat from the heat transferred by the heating medium in the first drying furnace 120,
The sewage sludge introduced into the second drying furnace 150 is placed on the conveyor belt 162 and is transported along the upwardly inclined conveyor belt 162 after heat transfer with the thermal oil in the container 164, Wherein the thermal oil contained in the sewage sludge can be discharged to the lower portion of the conveyor belt (162) in the form of a mesh net. The method according to claim 1,
A fan positioned above the first drying furnace or above the hopper to discharge steam generated in the first drying furnace to the outside;
Wherein the sludge drying apparatus further comprises: delete delete delete delete delete

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