WO2011142525A1

WO2011142525A1 - Closed-loop-type apparatus for drying sludge using airflow

Info

Publication number: WO2011142525A1
Application number: PCT/KR2011/000377
Authority: WO
Inventors: 조은만
Original assignee: (주)리엔텍엔지니어링
Priority date: 2010-05-14
Filing date: 2011-01-19
Publication date: 2011-11-17
Also published as: KR101006466B9; KR101006466B1

Abstract

The present invention relates to a closed-loop-type apparatus for drying sludge using airflow, and more particularly, to a sludge-drying apparatus which removes moisture from sludge using an airflow. The sludge-drying apparatus comprises: a mixer into which original sludge and dried sludge are fed and mixed to form a sludge mixture; a first air supplier which supplies air to the sludge mixture fed from the mixer, and increases the velocity of the air to crush the sludge mixture and inject the crushed sludge; a plurality of first cyclone driers, each including a first chamber which is connected to the first air supplier and which is conically shaped, a first cone which is arranged on the bottom of the first chamber and which is shaped as an inverse cone, and a first inner pipe arranged in the center of the first chamber, wherein the first cyclone driers enable the sludge mixture and air fed into the driers to swirl, so as to dry the sludge mixture; a first cyclone separator connected to the first inner pipe and shaped as a cone, wherein the first cyclone separator discharges the air fed therein through an upper portion thereof and separates the dried sludge to a lower portion thereof; and a dehumidifier which lowers the humidity of the air and raises the temperature of the air discharged from the first cyclone and resupplies the air to the first air supplier, thereby significantly improving drying efficiency and drying the sludge in an eco-friendly manner.

Description

Closed Loop Sludge Air Dryer

The present invention relates to a closed-loop sludge airflow drying apparatus, and more specifically, to remove moisture contained in the sludge by using an air stream of air without using a heat source, and to dry the air, which has undergone a drying process. The present invention relates to a sludge airflow drying apparatus capable of increasing the drying efficiency by recovering, lowering the humidity, raising the temperature, and supplying it back to the airflow used for drying.

The technology to remove moisture from waste material, that is, waste water sludge, is a process technology using a dehydrator, but it is very difficult to reduce the ratio of water contained in the sludge (hereinafter referred to as 'water content') to 80% or less by weight with conventional dehydration technology. It is difficult.

The total amount of industrial wastewater sludge produced annually in industrial wastewater treatment plants operated by domestic companies is about 4.8 million tons. Most of the primary dewatered wastewater sludge is discharged to the ocean like sewage sludge, and more than 90% of livestock manure Although the statistics indicate that land is recycled on land, and the remainder is being discharged to the ocean, dumping at sea is prohibited due to marine pollution.

Therefore, in order to solve such various sludge treatment problems, it is necessary to first reduce the total amount of generation. Above all, the reduction of water, which accounts for most of the sludge weight, is very important. It can be usefully used.

Most sewage treatment process including sewage consists of dewatering process, which is the final process technology.The mechanical dehydration device separates some of the free water in the water in the sludge by centrifugation or filter pressing, and the water content of about 80 ~ 85% is achieved. Eggplant drained into cake. That is, most of the final sludge weight occupies the residual water, which causes many environmental and economic difficulties in the treatment of the final sludge.

When the dewatered sludge is directly put into the drying facility, the sludge is not easily separated from each other due to the moisture and organic matter contained in the sludge. In addition, the sludge has high adhesiveness in the high water content range, resulting in low moisture reduction and low drying performance.

In particular, in the case of sewage, organic wastewater sludge, and livestock or human waste sludge classified as organic sludges, that is, the proportion of organic solids (Volatile solid) to total solids, that is, VS / TS ratio of 60% or more, The test results showed that the reduction performance was lowered. This is because, when the organic component is high, the higher the water content is due to the interaction with the contained moisture, the lower the water separability.

Therefore, in order to change the material state of the organic sludge, it is necessary to lower the inflow water or lower the organic component ratio, and the method may artificially adjust the component ratio of the material in the inflow sludge or apply thermal input such as combustion.

Here, the combustion of organic components due to thermal input causes high energy consumption and causes secondary environmental pollution such as VOC generation due to combustion.

Alternatively, in order to reduce energy, there is a method of adding a material containing a large amount of separate inorganic components (such as slaked lime) in the inflow stage of the one sludge, but there is an additional cost for these additives.

In order to solve such an overall problem, the present applicant has previously used the sludge drying apparatus using air transfer in Korean Patent Registration No. 10-0485223 (2005.4.15), without using a separate heat source. The device for drying has been applied for and registered.

Briefly, a sludge injector for supplying finely divided sludge by rotating the rotary wheel in the body frame; The air blower is connected to the lower part of the sludge injector and is positioned at the upstream end of the sludge injector connection position, and the concentric type reduction tube, the air flow amplifier housing, the air flow amplifier housing, and the fault are gradually reduced in diameter downstream thereof. An air conveying apparatus in which an air flow amplifier including a first air inlet for supplying air to a space between the reduction tubes is provided; A plurality of vertical bars connected to the air conveying apparatus, the upper surface of which is inverted throttle inlet at the bottom of the cyclone chamber, an inner tube at the center of the cyclone chamber, and a second air inlet for supplying air to the side of the throttle inlet; Multistage cyclone dryer; An air supply header receiving air from the air blower and supplying air to the first air inlet and the second air inlet; A cyclone separator connected to a transfer pipe connected to the cyclone dryer and connected to an air discharge device for discharging residual air at an upper portion thereof, wherein sludge solids are collected at a bottom of a cyclone chamber; And an automatic discharge device connected to the lower portion of the cyclone separator to discharge dry solids.

However, even when the sludge is dried using only a gas stream without a separate heat source using a conventional cyclone dryer, there is a limit in reducing the moisture content of the final dry sludge because the water content of the raw sludge is high.

The present invention has been made to solve the above problems, an object of the present invention is to increase the drying efficiency by lowering the humidity of the air with high humidity to remove the moisture contained in the sludge and increasing the temperature to re-feed to the airflow drying apparatus It is to provide a closed loop sludge airflow drying apparatus that can be.

The present invention for achieving the above object, the sludge drying apparatus for removing the water of the sludge by using an air stream, a mixer for making the sludge mixed with the raw sludge and dry sludge; A first air feeder for supplying air to the mixed sludge introduced from the mixer and increasing the flow rate to inject the mixed sludge while crushing the mixed sludge; A first chamber connected to the first air supply and configured to have a conical shape, a first cone provided at a bottom of the first chamber and having a reverse cone shape, and a first inner tube positioned at the center of the first chamber; A plurality of first cyclone dryers configured to rotate the mixed sludge and air injected therein to dry the mixed sludge; A first cyclone separator connected to the first inner tube and having a conical shape, the introduced air is discharged to the upper portion and the dried dry sludge is separated into the lower portion; And a dehumidifier for lowering the humidity of the air discharged from the first cyclone separator and raising the temperature to resupply the first air feeder.

Here, the dehumidifier may be composed of an evaporator for cooling the air discharged from the first cyclone separator to remove moisture contained in the air, and a condenser for raising the temperature of the air passing through the evaporator.

Some of the dry sludge separated in the first cyclone separator may be re-supplied to the mixer and mixed with the raw sludge.

In another aspect, the present invention is connected to the first cyclone separator is a second air feeder for supplying air to the drying sludge introduced from the first cyclone separator to increase the flow rate; A second chamber connected to the second air feeder and having a conical shape, a second cone provided at the bottom of the second chamber and having an inverted cone shape, and a second inner tube positioned at the center of the second chamber. A plurality of second cyclone dryers; And a second cyclone separator connected to the second inner tube and formed in a conical shape, wherein the dry sludge is separated into the lower part and the air is discharged to the upper part to return to the dehumidifier, thereby reducing humidity in the dehumidifier. The air having the elevated temperature may be resupplied to the second air feeder.

At this time, between the second cyclone separator and the dehumidifier is characterized in that the bag filter for removing the dust contained in the air discharged from the second cyclone separator.

Effects of the present invention by the above configuration is as follows.

Drying efficiency is greatly improved because air is not supplied to the air supply to the air blower, but is supplied again with high-temperature dry air having a lower humidity and a higher temperature.

In addition, the system consisting of an air blower, a cyclone dryer, and a cyclone separator is provided in two stages, so that the water reduction effect is more excellent.

In addition, pollutants and dust generated in the exhaust air are filtered by the bag filter from the inside and supplied to the dehumidifier to be used for drying, which is environmentally friendly.

1 is a block diagram showing a closed loop sludge airflow drying apparatus according to an embodiment of the present invention.

Figure 2 is a block diagram showing a closed loop sludge airflow drying apparatus according to another embodiment of the present invention.

3 is a block diagram showing a mixer of the present invention.

Figure 4 is a block diagram showing a screw conveyor and a classifier of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. The following description and the accompanying drawings are presented for the overall understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. And a detailed description of known configurations and functions that may unnecessarily obscure the subject matter of the present invention will be omitted.

Hereinafter, 'one sludge' refers to dewatered sludge before drying, which has a water content of about 80 to 85% only by mechanical dehydration, and 'dry sludge' refers to sludge dried through a dryer, and 'mixed sludge' Dry sludge means mixed. Also, 'Dry solid (DS)' means solid material except water in components such as raw sludge, dry sludge and mixed sludge, so that the weight of dry solid increases when the moisture content decreases in the total weight of sludge. .

The sludge drying apparatus of the present invention may be configured to include a mixer 100, a first air feeder 200, a first cyclone dryer 300, a first cyclone separator 400, a dehumidifier 500. The raw (dewatered) sludge and the dried sludge primarily dried are mixed in the mixer 100, and the mixed mixed sludge is sprayed to the cyclone dryer 300 by the first air feeder 200. And mechanically dried while forming an airflow, the dried dry sludge is separated and discharged from the cyclone separator 400 with air, and the air is returned to the dehumidifier 500 to remove humidity contained therein to lower humidity. In addition, after increasing the temperature it is repeated to supply to the first air feeder 200 again.

First, the mixer 100 may be any device that can be mechanically mixed. In the present invention, the mixer 100 may be largely composed of a mixing tank 120 for accommodating raw sludge and dry sludge, a mixing screw 140 for mechanically mixing, and a conveying screw 160 for conveying the mixed mixed sludge. The detailed description will be described later with reference to FIG. 3.

Next, since the first air feeder 200, the first cyclone dryer 300, and the first cyclone separator 400 are well-known techniques known by the applicant, a brief description thereof will be provided.

The first air feeder 200 is configured to spray mixed sludge to the first cyclone dryer 300 by strongly blowing and supplying (feeding) air by receiving mixed sludge mixed and discharged from the mixer 100. to be. As shown in FIG. 1, a first blower 220 for blowing air and a first flow amplifier 240 for amplifying a flow rate of air generated by the first blower 220 may be included.

Therefore, the high-speed air injected by the first flow amplifier 240 disperses the granulated sludge while crushing the mixed sludge. The granulated mixed sludge is brought into contact with the specific surface area by flowing with the air, thereby effectively dehumidifying.

The first cyclone dryer 300 has a conical first chamber 320 connected to the air and mixed sludge from the first air supply 200, and a reverse conical shape at the bottom of the first chamber 320. It consists of a first cone 340 and a first inner diameter 360 disposed vertically to the center of the first chamber 320 on the upper side of the first cone 340. Therefore, the introduced air and the mixed sludge have a turbulent flow (Vortex flow) while turning spirally inside the first chamber 320, and the velocity increases as it descends, so that the mixed sludge particles are reduced in size due to collisions and frictional heat. This occurs and dries.

At this time, the moisture removed from the mixed sludge is included in the air, thereby increasing the humidity of the air.

Preferably, the first cyclone dryer 300 may be provided in a plurality of stages, and more preferably two may be appropriate.

The first cyclone separator 400 is connected to the first cyclone dryer 300 and has a conical shape, and an air outlet through which residual air is discharged is formed at the top thereof, and dried dry sludge is collected at the bottom. It is the same principle as the dust collector.

For reference, the air discharged from the first cyclone separator 400 has a relative humidity of about 95% or more and a temperature of about 28 ° C.

Next, the dehumidifier 500 is connected to the first cyclone separator 400 to remove moisture contained in the air discharged from the first cyclone separator 400 to lower the humidity and increase the temperature to adjust to high temperature dry air. do. The dehumidifier 500 may be configured as an evaporator and a condenser.

The evaporator uses a refrigerant to evaporate the refrigerant while evaporating the refrigerant, and vaporizes the refrigerant. The evaporator takes water from the air discharged from the first cyclone separator and cools it to remove moisture.

The condenser releases heat to the surroundings, and the refrigerant liquefies to increase the temperature of the air passing through the evaporator.

Since the evaporator and the condenser have a known technology and function, detailed description thereof will be omitted.

The air passing through the evaporator and the condenser has a low humidity and a high temperature, resulting in high temperature drying. For reference, the air passing through the dehumidifier 500 may have a relative humidity of about 30% or less and a temperature of about 40 ° C.

The dehumidified air is supplied to the first air feeder 200 again and forms a closed loop which is circulated while repeatedly passing through the above-described devices.

Therefore, there was an unstable problem when using the atmosphere for the conventional drying, it is possible to ensure a very stable drying performance because the stabilization of the state of the air in the present invention resupplied.

On the other hand, the dry sludge separated and discharged from the first cyclone separator 400 is generally about DS 55%, can be reheated and re-dried by the screw conveyor 700 to be described later, the re-dried dry sludge is to be described later Classified by the air supply 800 may be mixed with the raw sludge by re-supplying the portion to the mixer 100 again. The structure of the screw conveyor 700 and the classifier 800 will be described later.

Referring to FIG. 2, another embodiment of the present invention further includes a second air feeder 200 ′, a second cyclone dryer 300 ′, and a second cyclone separator 400 ′ in the embodiment shown in FIG. 1. The dry sludge separated and discharged from the first cyclone separator 400 may be supplied to the second air feeder 200 ′ and the second cyclone dryer 300 ′ to be dried once more.

In addition, the air discharged from the second cyclone separator 400 ′ is sent to the dehumidifier to lower the humidity and increase the temperature to repeat the supply of the air to the second air feeder 200 ′.

The second air blower 200 'may include a second blower 220' and a second flow amplifier 240 ', and the second cyclone dryer 300' may include a second chamber 320 '. , The second cone 340 ′, and the second inner tube 360 ′. Since each of the first blower 220, the first flow amplifier 240, the first chamber 320, the first cone 340, and the first inner tube 360 may have a structure that is substantially the same as that of the detailed description. Is omitted. The second cyclone separator 400 ′ is also substantially the same as the first cyclone separator 400.

At this time, the first cyclone separator 400 and the second air feeder 200 'are connected to the discharged dry sludge to be injected into the second flow amplifier 240' of the second air feeder 200 '. Can be.

In addition, the upper part of the second cyclone separator 400 ′ is connected to the dehumidifier 500 and the air discharged is recovered to the dehumidifier 500. Of course, the dehumidifier 500 is connected to the second blower 220 'of the second air blower 200' so that the dehumidified air is discharged by the second air blower 200 '. 300 ').

In other words, the air is circulated while forming a separate closed loop by the first air feeder 200 and the second air feeder 200 '.

Preferably, the upper portion of the second cyclone separator 400 'is further provided with a bag filter 600 to filter contaminants, dust, dust, etc. contained in the air discharged from the second cyclone separator 400' The dehumidifier 500 may be supplied.

Conventionally, exhaust air is consumed by additional treatment in a wet scrubber, but in the present invention, air is not only discharged to the outside while circulating inside the system, but also to filter out contaminants from the bag filter 600. There is also an advantage to reduce.

In addition, a screw conveyor 700 may be provided below the second cyclone separator 400 ′ to perform additional drying. In fact, the DS of dry sludge that has been processed is almost 90% or more.

Hereinafter, the mixer 100, the screw conveyor 700, and the classifier 800 described above will be briefly described with reference to FIGS. 3 and 4. 3 is a block diagram showing a mixer of the present invention, Figure 4 is a block diagram showing a screw conveyor and a classifier of the present invention.

Referring to FIG. 3, the mixer 100 is a device for mixing dry sludge with primary sludge, which is primarily dried to reduce moisture content, and includes a mixing tank 120, a mixing screw 140, and a transfer screw 160. Can be configured.

The mixing tank 120 is a space in which mixing is performed, and an inlet and an outlet may be formed at an upper portion thereof.

In addition, a pair of mixing screws 140 may be provided in the mixing tank 120. The mixing screw 140 is disposed in parallel and horizontally and evenly mixed with the dry sludge and the original sludge.

In addition, the conveying screw 160 is disposed below the mixing screw 140 and rotates to convey the mixed sludge to one side. The conveyed mixed sludge may be controlled by using an inverter in order to supply a fixed amount to the cyclone dryer 300 to be described later.

Next, the screw conveyor 700 is connected to the lower portion of the first cyclone separator 400 or the second cyclone separator 400 'to further lower the moisture content of the dry sludge.

Referring to FIG. 4, an inlet and an outlet through which the dry sludge flows in and out may be formed on one side, and a screw is installed along the longitudinal direction to convey the introduced dry sludge while rotating.

Next, the classifier 800 receives the dry sludge transported by being coupled to the lower portion of the screw conveyor 700 connected to the first cyclone separator 400 and quantitatively separates them.

The classifier 800 has a shape similar to that of the 'Y' is arranged upside down, forming a hollow tube shape and an injection hole into which the dry sludge heated by the screw conveyor 700 is injected at the upper portion, and classified at the lower portion. Two discharge ports may be formed to discharge the dry sludge to both sides.

A part of the dry sludge discharged through the classifier 800 is used to recover and mix the mixer 100, and the rest is supplied to the second flow amplifier 240 'of the second air feeder 200'. do. Usually divided into half can be supplied separately.

Hereinafter, the sludge airflow drying method using the closed loop sludge airflow drying apparatus of the present invention will be described.

First, the first step is to produce the mixed sludge by mixing the raw sludge and the first dry dry sludge in the mixer 100.

In the second step, the mixed sludge generated in the first step is injected into the first cyclone dryer 300 to supply air from the first blower 220 of the first air blower 200. Air may be increased by the first flow rate amplifier 240 and injected into the first cyclone dryer 300 by spraying the supplied mixed sludge.

The third step is a step in which the mixed sludge introduced into the first cyclone dryer 300 is dried, and the mixed sludge is formed by turning while forming turbulent flow with air and is introduced into the first cyclone separator 400.

The fourth step is a step in which the dry sludge introduced into the first cyclone separator 400 is separated from air and collected at the bottom, and the air is discharged to the top.

The fifth step is to recover the air discharged from the first cyclone separator 400 to the dehumidifier 500 to lower the humidity and increase the temperature, and then resupply the air to the first air feeder 200.

Preferred may further comprise the following steps.

In the sixth step, a part of the dry sludge separated from the first cyclone separator 400 in the fourth step is supplied back to the second air blower 200 'to be fed by the second blower 220'. Increasing the flow rate of air through the second flow amplifier (240 ') and injecting air into the second cyclone dryer (300').

The seventh step is a step of redrying the dry sludge introduced into the second cyclone dryer 300 'and introducing it into the second cyclone separator 400'.

In addition, the eighth step is a step of separating the dry sludge introduced into the second cyclone separator 400 'with air to collect it to the bottom and discharge the air to the top.

The ninth step is to recover the air discharged from the second cyclone separator 400 'to the dehumidifier 500 to lower the humidity and raise the temperature, and then resupply the air to the second air feeder 200'. .

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art, various modifications of the present invention within the scope of the claims without departing from the spirit and scope of the present invention And can be changed.

Explanation of sign

100: mixer 120: mixing tank

140: mixed screw 160: transfer screw

200: first air blower 220: first blower

240: first flow amplifier

200 ': second air blower 220': second blower

240 ': second flow amplifier

300: first cyclone dryer 320: first chamber

340: first cone 360: first inner view

300 ': second cyclone dryer 320': second chamber

340 ': 2nd cone 360': 2nd inner view

400: first cyclone separator 400 ': second cyclone separator

500: dehumidifier 600: bag filter

700 screw conveyor 800 classifier

The present invention can be used in the closed-loop sludge airflow drying apparatus, and more specifically, by removing the moisture contained in the sludge by using a stream of air without using a heat source, the air is high humidity after drying It is possible to use the sludge airflow drying apparatus that can increase the drying efficiency by recovering and lowering the humidity, raising the temperature, and supplying it back to the airflow used for drying.

Claims

In the sludge drying apparatus for removing the water of the sludge by using the air stream,

Mixer 100 to make the sludge mixed with the raw sludge and dry sludge;

A first air feeder 200 for supplying air to the mixed sludge introduced from the mixer 100 and increasing the flow rate to inject the mixed sludge while crushing the mixed sludge;

A first chamber 320 connected to the first air feeder 200 and having a conical shape; a first cone 340 provided at a bottom of the first chamber 320 and having a reverse cone shape; A plurality of first cyclone dryers 300 including a first inner diameter tube 360 positioned at the center of the chamber 320 to rotate the mixed sludge and air injected therein to dry the mixed sludge;

A first cyclone separator 400 connected to the first inner tube 360 and formed in a conical shape to discharge the introduced air to the upper portion and separate the dried dry sludge to the lower portion;

Closed loop type sludge airflow drying, comprising: a dehumidifier (500) for lowering the humidity of the air discharged from the first cyclone separator (400) and increasing the temperature to resupply the first air feeder (200). Device.
The method of claim 1,

The dehumidifier 500 comprises an evaporator that cools the air discharged from the first cyclone separator 400 to remove moisture contained in the air, and a condenser that raises the temperature of the air passing through the evaporator. Closed loop sludge airflow drying device.
The method of claim 2,

A part of the dry sludge separated from the first cyclone separator 400 is re-supplied to the mixer 100 and mixed with the raw sludge.
The method of claim 3, wherein

A second air feeder (200 ′) connected to the first cyclone separator (400) for supplying air to the dry sludge introduced from the first cyclone separator (400) and for increasing the flow rate thereof;

A second chamber 320 'connected to the second air feeder 200' and formed in a conical shape; a second cone 340 'provided at a bottom of the second chamber 320' and formed in an inverted cone shape; A plurality of second cyclone dryers 300 'including a second inner diameter tube 360' positioned at the center of the second chamber 320 '; And

The second cyclone separator 400 'is connected to the second inner tube 360' and has a conical shape, and the dry sludge is separated into the lower part and the air is discharged to the upper part to return to the dehumidifier 500. More equipped,

Closed loop sludge airflow drying apparatus, characterized in that for supplying the dehumidified and reheated air from the dehumidifier 500 to the second air feeder (200 ').
The method of claim 4, wherein

A closed loop between the second cyclone separator 400 'and the dehumidifier 500 is provided with a bag filter 600 for removing dust contained in the air discharged from the second cyclone separator 400'. Sludge Airflow Dryer.