KR20070075380A - Energy saving sludge dry method of construction used by pneumatic - Google Patents

Abstract

A method for drying sludge is provided to decrease the percentage of water content in sludge without an additive heat source or apparatus, thereby reducing the disposal cost of sludge, by drying hydrated sludge cake with high-temperature air jetted from an air blower. Much high-temperature air is supplied to a biological process bath(9) from an air blower(1). The high-temperature air is connected to an air pipe at the rear of the air blower. A sludge supply unit(11) supplies sludge cake exhausted from a dehydrator through the air pipe. A hopper is formed with the sludge supply unit in a single body or separately. A drier(12) is connected to the sludge supply unit through the air pipe. The sludge and air passing through the drier is divided into dried sludge and low-temperature air by a liquid separator(13) connected to the rear of the drier. The dried sludge is collected below the liquid separator, and the low-temperature air is reused within the biological process bath via a pipe connected to the liquid separator.

Description

Energy saving sludge drying method using air {Energy Saving Sludge Dry Method of Construction used by Pneumatic}

1 is a general water treatment process diagram of a conventional sewage and wastewater treatment plant.

Figure 2 is a process chart combining the method according to the present invention in the general water treatment process of a conventional sewage and wastewater treatment plant.

3 is a process diagram of air supply of a biological treatment tank of a conventional sewage and wastewater treatment plant.

Figure 4 is a process chart combining the process according to the present invention in the air supply process diagram of a conventional biological treatment tank of sewage and wastewater treatment plant.

5 is a schematic diagram of a dehydration sludge cake drying system of a conventional sewage and wastewater treatment plant.

FIG. 6 is a schematic diagram of a dewatered sludge cake treatment system of the present invention for better understanding of FIGS. 2 and 4.

Explanation of symbols on the main parts of the drawings

1. Blower (other air generator)

1-a. Blower

2. thermometer, manometer

3. Check valve

4. Butterfly Valve

5. Air chamber

6. Air cooling device (heat exchanger)

7. Cooling tower

8. Air piping

9. Biological treatment tank (aeration tank or microbial reaction tank)

10. Auxiliary heat source device (heater)

11. Dewatered Sludge Feeder

12. Dryer

13. Fluid separator (cyclone separator)

14. Dust collector

Annual discharge of sludge from national sewage treatment plant in 2006 was 2,543,000 tons. The treatment methods were 75% of ocean dumping, 9.2% of incineration, 4.8% of landfill and 11% of reuse.

However, since March 2011, the dumping of ocean dumping has been banned by the International Convention on the Prevention of Pollution of the Marine Environment (Second London Protocol), and sludge reduction and treatment are a major problem.

At present, there is no separate plan other than incineration, landfilling, and reuse among sludge treatment methods.In addition, as the sludge drying is essential for such treatment, many applications of the technology have been developed. The cost of fuel and the operating costs for additional systems are also enormous. Therefore, before the final disposal of the sludge generated in the treatment plant is directly or indirectly to reduce the water content of the sludge, the energy saving high efficiency sludge drying method that can reduce the transport and treatment costs, incineration cost, etc. is required. .

As in the conventional sludge drying apparatus using air transfer (Registration Room 20-0372172), a cyclone separator is installed to separate dry sludge and a small amount of sludge dust from multi-stage cyclones, and the dried sludge is discharged to the bottom of the cyclone separator. The separated air is discharged to the atmosphere through the scrubber tower. Since the air discharged from the drying apparatus has a small amount of dust and odor, a deodorizing tower using a cleaning tower and activated carbon must be used. However, such a simple treatment method does not completely remove odors and volatile organic compounds, and in this connection, enormous additional equipment costs and operation costs are accompanied.

The present invention is installed in the rear of the blower (other air generating device) for supplying air to the biological treatment tank (aeration tank or microbial reaction tank) in the sewage, wastewater, water purification treatment plant of existing or new construction, the air used for drying the biological treatment It is a process that is reused in tanks (aeration tanks or microbial reaction tanks), so sludge can be dried without heat source or power unit for odor removal, and it can reduce enormous installation and operation costs and post-treatment facilities. have.

An object of the present invention is to provide a process for dry separation of sludge using a large amount of high-temperature air from the blower (other air generator) of the existing sewage and wastewater treatment plant and recycling to the biological treatment tank.

Another object of the present invention is to provide a process for removing the dust and odor generated in the dryer rear end equipment for the existing sludge drying without a separate equipment.

Another object of the present invention is to increase the water temperature in the biological treatment tank due to the supply of a large amount of high temperature air from the blower (other air generator) of the existing sewage and wastewater treatment plant to reduce the activity of aerobic microorganisms to reduce the efficiency of water treatment It is to provide a process that can solve the problem.

The above and other objects of the present invention can be achieved by the effects of the following invention.

The present invention relates to a process for drying and reducing the sludge by using a large amount of high-temperature air used in the existing process without a separate heat source or power to the high water content sludge cake discharged from the dehydrator of the waste water treatment plant More specifically, a large amount of hot air supplied from a blower (other air generator) to a biological treatment tank (aeration tank or microbial reaction tank) in a water treatment process of a sewage and wastewater treatment plant is first used as a drying heat source of a sludge cake. Blower (other air generators) for the purpose of reducing energy costs as well as reducing sludge by reducing the treatment cost and minimizing the environmental pollution that occurs secondly; A sludge supply unit connected to the rear end of the blower and configured to supply dehydrated sludge cake; A dryer for drying the hot air and sludge supplied from the sludge supply apparatus; A fluid separator (cyclone separator) for separating the dried sludge solids and the air; A sludge storage hopper for storing the separated sludge; A pipe for supplying air used as a heat source for drying; And it is characterized by consisting of a biological treatment tank to supply air.

The sludge dryer is preferably a drying step of drying the sludge using a high temperature air and a large amount of air.

An auxiliary heat source such as a heater may be used at the rear end of the blower (air generator) to replenish and preheat the heat source.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a general water treatment process diagram of a conventional sewage and wastewater treatment plant.

The water treatment process of sewage and wastewater treatment plant is divided into water treatment process and sludge treatment process. Sewage and wastewater (hereinafter referred to as "sewage") generally introduced include sewage from the sediment with sewage, and flow control tanks and reactors After the sewage in the primary sedimentation tank for a certain period of time, the sedimentary and floating materials are separated from the sewage and removed.

Biological treatment tanks (aeration tanks or microbial reaction tanks) use aerobic microorganisms by supplying air to the sewage that flows in so that they can be easily separated by contaminating pollutants. The mixed liquor from the reactor is stopped and separated into activated sludge and supernatant, which is sent to a dehydrator and the treated water is discharged.

The sludge treatment process reduces gravity by long-time gravity sedimentation of sludge produced in the water treatment process in the concentration tank, and reduces the volume and weight through digestion tanks and dehydration equipment, and makes the sludge state for easy transportation and disposal. It has a relatively high water content of about 80%, and can cause secondary pollution with odor.

Figure 2 is a process chart combining the method according to the present invention in the general water treatment process of a conventional sewage and wastewater treatment plant.

FIG. 2 is a process chart combining dehydration sludge cake drying process in the general water treatment process of the conventional sewage and wastewater treatment plant of FIG. 1, since a biological treatment tank uses aerobic microorganisms, a large amount of air from a blower (other air generator) It is necessary. At this time, since the pressure of the air generated by the blower must overcome the head pressure of the head of the biological treatment tank, it is necessary to generate hot air having the pressure of the head height.

At this time, when a large amount of high temperature air from the blower (other air generator) to the biological treatment tank to increase the water temperature of the treatment tank to lower the activity of aerobic microorganisms to lower the efficiency of the water treatment as shown in Figure 3 separate from the blower Air cooling system (heat exchanger) 6 is provided.

Therefore, Figure 2 uses a large amount of hot air generated in the blower (other air generator) as a heat source for drying the high water content sludge cake (Dewy) from the dehydrator, a large amount of high temperature air used is a separate An air cooler (heat exchanger) is unnecessary. In addition, the odor in the air generated during drying is also acidified in the biological treatment tank (aeration tank or microbial reaction tank), so there is no need to deodorization equipment such as a scrubber or deodorization tower to remove the odor.

3 is an air supply process diagram of a biological treatment tank of a conventional sewage and wastewater treatment plant for comparison with the present invention.

Figure 4 is a process chart combining the process according to the present invention in the air supply process diagram of a conventional biological treatment tank of sewage and wastewater treatment plant.

At the rear end of the blower 1 of FIG. 4, an auxiliary heat source device 10 such as a heater can be used if necessary, and the auxiliary heat source device 10 is a dewatered sludge supply device for introducing a sludge cake from the dehydrator. (11); A dryer 12 connected to the dewatered sludge supply device 11; A fluid separator (cyclone separator) 13 for separating the dry sludge from the dryer 11 and air; Composed of a control panel for controlling the dewatering sludge supply apparatus 11 and the blower (1) is characterized in that the separated air is reused in the biological treatment tank (aeration tank or microbial reaction tank) (9).

5 is a schematic diagram of a dehydration sludge cake drying system of a conventional sewage and wastewater treatment plant.

In the schematic diagram of FIG. 5, a scrubber or deodorization tower capable of removing a small amount of dust and odors is used at the rear of the dryer and the fluid separator (cyclone separator), and requires separate energy and additional equipment to operate the same.

FIG. 6 is a schematic diagram of a dewatered sludge cake treatment system of the present invention for better understanding of FIGS. 2 and 4.

The secondary problem occurring at the rear end of the fluid separator (cyclone separator) of FIG. 5 is supplied to an existing biological treatment tank (aeration tank or microbial reaction tank) in such a manner that the second problem can be removed without a separate heat source or device. By using high temperature air to dry dewatered sludge and then to biological treatment tank (aeration tank or microbial reaction tank), equipment cost related to air cooling system (heat exchanger) 6 and separate drying operation cost for sludge drying It is a process that can reduce the cost for waste and sludge treatment and simultaneously remove dust and odor generated at the back of the dryer.

In addition, the process is a dewatering sludge supply device for supplying a dewatered sludge cake (Cake) coming from the dehydrator may have a storage tank capable of storing one or a separate dewatered sludge cake (Cake).

The type of dryer 12 and fluid separator (cyclone separator) 13 that can be used in the above process may use various kinds of dryers and fluid separators depending on the type of air generator supplied to the dryer.

The present invention is a process for installing a dryer at the rear of the blower (other air generators), separating the sludge dry particles and air with a fluid separator (cyclone separator) to supply the separated air to the biological treatment tank, the existing blower The hot air discharged directly enters the biological treatment tank and increases the water temperature, which directly affects the water treatment. The hot air is used as a heat source for drying and separating the sludge cake, and the used air is supplied to the biological treatment tank as low temperature air to increase the activity of microorganisms to increase water treatment efficiency. Therefore, there is no need for additional equipment such as an air cooling system to be installed at the rear of the existing blower.

In addition, in the general drying method, the air containing the odor generated in the sludge drying process is reused in the biological treatment tank, there is no need for a separate odor removal facility deodorizing equipment. In the process of drying the dewatered sludge cake with hot air discharged from the blower, drying the sludge without additional heat source or device, reducing the water content, reducing the sludge treatment cost, and removing the air that is discarded into the atmosphere from the existing dryer. By recycling, energy can be drastically reduced, and there is no need for dust removal device or odor removal device, which simplifies the installation and reduces installation area, installation cost and operating cost.

And unlike the existing treatment plants, the air passing through the dryer is not a high temperature air, so a separate air cooling cooling device is unnecessary, and the microorganism is activated by supplying an appropriate air temperature, which helps to improve the water quality. It has the effect of preventing secondary environmental pollution such as leachate from high sludge.

Claims (5)

The present invention is a large amount of high-temperature air discharged from the blower (other air generator) (1) required for the existing process without a separate heat source or device for the sludge cake (High) content discharged from the dehydrator of the waste water treatment plant It relates to a process of drying the sludge to lower the water content, reduce and resource by using, more specifically, the biological treatment tank (aeration tank or aeration tank) in the water treatment process of the wastewater treatment plant (1) A large amount of hot air supplied to the microbial reactor (9); The hot air is connected to the air pipe of the rear end of the blower (1), the air pipe is a sludge supply device for supplying a dewatered sludge cake (Cake) discharged from the dehydrator; A hopper integral or separate with the sludge feeder 11; It is connected to the sludge supply apparatus 11, and is connected to the dryer 12 through the air pipe; The sludge and air passing through the dryer 12 separates the dried sludge and the air at a lower temperature through a fluid separator (cyclone separator) 13 connected to the rear end of the dryer, and the sludge having a high specific gravity is the fluid separator ( The air separated into the lower portion of the cyclone separator (13), and the air having a low specific gravity are connected to the pipe behind the fluid separator (cyclone separator) 13, and the air to be reused in the biological treatment tank (aeration tank or microbial reaction tank) 13 is used. It is an energy-saving sludge drying method used. The drying process according to claim 1, wherein an auxiliary heat source device (heater) 10 or the like is provided at the rear end of the blower 1. The drying process according to claim 1, wherein a separate dust collector (14) is provided at the rear end of the fluid separator (cyclone separator) 13. The drying apparatus of claim 1, wherein the dryer 12 includes a dryer using hot air. 5. The sludge drying process according to claim 4, wherein the sludge drying process uses high temperature air of a blower (other air generating device) 1 for sludge drying in an existing or newly-established sewage treatment plant, wastewater treatment plant, water treatment plant, and the like. Includes drying process for reuse in tank (aeration tank or microbial reaction tank) (9)

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