WO2019088399A1 - System for drying sludge reheated by circulated steam - Google Patents

Abstract

A system for drying sludge reheated by circulated steam according to the present invention includes: a dryer which receives a sludge and dries the moisture of the sludge by means of a heat source, thereby forming a dry sludge material; a deodorizing furnace which receives a dry distilled gas, which is generated in the dryer, through a transfer line, and burns the dry distilled gas, thereby removing the moisture and odorous ingredients contained in the dry distilled gas; a steam heater which uses the deodorized gas discharged from the deodorizing furnace to heat the dry distilled gas supplied through a circulation line branched from the transfer line through heat-exchange, and supplies the heated dry distilled gas to the dryer as a heat source; an exhaust fan installed on the transfer line and controlled by an automatic damper according to the downstream pressure of the dryer to supply the dry distilled gas to the deodorizing furnace; and a circulation fan installed on the circulation line and supplying to the steam heater, the remaining dry distilled gas in the transfer line from which an amount, corresponding to the moisture evaporated in the exhaust fan, of the dry distilled gas has been removed.

Description

Cyclic steam reheat sludge drying system

The present invention relates to a circulating steam reheating sludge drying system, and more particularly, to a circulating steam reheating sludge drying system for efficiently treating sewage sludge or organic waste with a minimum energy.

As the amount of sludge generated in the water treatment process of water, industrial water, industrial wastewater, sewage and manure is increased, the size and number of the treatment plant for treating this increase and the amount of sludge generated in these treatment plants are also increasing .

In particular, the government has steadily promoted the establishment of sewage treatment plants, the expansion of sewage treatment plants, the maintenance of sewer pipes, the installation of treatment facilities for guns, and the amount of sewage sludge generated has steadily increased. In addition, sewage sludge will continue to increase .

However, since the sewage sludge is generated in the form of a liquid containing 95 to 98% of water, it is difficult to handle the sludge. Usually, the sludge is treated with sand filtration, filter press, centrifugal dehydrator, Most of them are processed by various methods such as landfill, fuel conversion, solidification, incineration, and pyrolysis.

However, a large amount of water present in the sludge causes an increase in landfill cost and serious environmental pollution due to an increase in weight and volume during landfilling, and it gradually becomes a social atmosphere such as enforcement of environmental regulation law and environmental awareness, It is necessary to reduce the amount of sludge as it becomes difficult.

Conventionally, steam is generated using a boiler to indirectly heat the sludge with high-temperature steam to reduce moisture in the sludge. By reducing moisture in the sludge, the high-temperature air having increased humidity is cooled to be condensed And discharging it to the outside has been used.

However, since the indirect sludge drying apparatus using the boiler of this structure discharges the high temperature air which is not deodorized to the outside in order to reduce the humidity, the environment of the drying apparatus becomes poor and the heat of the air discharged to the outside causes the boiler The amount of fuel injected into the fuel cell is increased, and energy can not be efficiently used.

The present invention minimizes air pollutants by eliminating dust and odors generated during the treatment and treatment of sludge generated from sewage or organic wastes with minimum energy and preserves the environment around the sludge treatment facility, And to prevent the occurrence of such a phenomenon.

According to an aspect of the present invention, there is provided a sludge drying apparatus including a dryer for drying sludge moisture by a heat source supplied with sludge and a sludge dryer, A deodorizing furnace for removing water and odor components contained in the dry gas, and a deodorizing gas discharged from the deodorizing furnace. The steam is supplied to the dryer through the heat exchanger to heat the dry gas supplied through the circulation line branched from the transfer line. It is installed in the heating and conveying line and controlled by the automatic damper according to the pressure of the downstream of the dryer to supply the dry gas to the deodorization furnace and the remaining dry gas which is installed in the circulation line and the evaporation amount of evaporated gas is removed from the exhaust blower, And a circulating blower for supplying the heat to the heater.

And a centrifugal dust collector installed in the transfer line for collecting the dust contained in the dry gas and discharging the dust to the lower part, and supplying the odor component to the deodorizing furnace.

The centrifugal force dust collector includes a first centrifugal force collector for separating dust in the drawn-in gas by centrifugal force, a first centrifugal force collector for separating dust in the drawn-in gas from the centrifugal force, Wherein the first centrifugal force collector, the first centrifugal force collector, and the second centrifugal force collector have a first concentration and a second concentration, respectively, of the first centrifugal force collector and the second centrifugal force collector after passing through the first centrifugal force collector, Accordingly, the electric dust collecting electrode needs to be cleaned, so that the electric dust collecting electrode can be selectively connected.

Wherein the first and second electrostatic centrifugal force collectors each have a dust concentration sensing unit for measuring the concentration of dust contained in the carbon dioxide gas passing through the centrifugal force collector at the upper outlet portion, Whether or not the first electrostatic centrifugal force collector and the second electrostatic centrifugal force collector are allowed to pass the carbon monoxide gas can be controlled.

The dust concentration sensing unit may be a laser sensor for sensing a dust pressure by irradiating a laser beam to an upper outlet portion of a centrifugal force dust collector through which a dry gas is discharged.

Wherein the first and second electrostatic centrifugal force collectors comprise: a cyclone for separating the dust in the carbon monoxide gas sucked by centrifugal force into lower parts; an electric dust collecting pole for attaching the fine particles inside the cyclone using a high voltage; And a water spray nozzle for spraying water to clean fine dust adhered to the pole.

The electric dust collecting pole may have a plurality of protrusions formed along an outer surface thereof.

A filter and a dust collector for removing ultrafine dusts of the deodorized gas discharged from the steam heater by a filter and a chimney for discharging the exhaust gas passed through the filter and dust collector to the outside.

The chimney has a double tube shape which surrounds the outer circumferential surface of the chimney. The chimney transfers the collected odor gas from the sludge storage tank, the sludge tank, the drier, the input facility, and the like, while transferring the odor gas to the heat of the exhaust gas passing through the chimney. And a preheater for supplying the deodorizing furnace to the deodorizing furnace by secondly heating the odor gas heated while passing through the transfer pipe through heat exchange with the deodorizing gas discharged from the steam oven.

The inside of the conveyance pipe may have a spiral shape so that the odor gas is circulated and circulated from the upper part of the chimney to the lower part thereof so as to be heated.

The dryer includes an inner space capable of receiving the sludge, a plurality of partition walls partitioning the inner space into a continuous drying chamber, a paddle type conveying conveyor installed in the drying chamber for conveying the sludge, A sludge inlet connected to a drying chamber located at the uppermost stage of the drying chamber; a drying agent discharge port located at the lower end of the plurality of drying chambers for discharging the dried sludge; a heat source inlet for drying the sludge; And a carbon dioxide gas outlet for discharging the carbon dioxide gas.

The dryer includes an oxygen concentration sensor installed in the dryer to detect an oxygen concentration and a nitrogen concentration sensor for purifying nitrogen gas by purging the inside of the dryer when the oxygen concentration detected by the oxygen concentration sensor is higher than a set concentration, And a gas purge portion.

A rotary valve installed at the dry material discharge port to discharge oxygen while shutting off oxygen when the dried sludge is discharged, and a discharge conveyor that can receive and discharge the dried sludge discharged from the rotary valve.

And a heat dissipating and recovering unit for recovering the heat radiated through the heat dissipating plate to preheat the sludge before the sludge is supplied to the dryer.

The heat dissipating and collecting means includes a circulation duct formed in the heat dissipation plate and a double pipe which surrounds the outer circumferential surface of the supply pipe for feeding the sludge to the dryer. One side of the circulation duct is connected to the inlet of the circulation duct, A circulation pipe connected to an outlet of the circulation duct for circulating heat radiated through the radiating plate, and a heat-radiating circulation blower for securing circulation power of the heat.

1 is a view showing a circulating steam reheating sludge drying system according to an embodiment of the present invention.

2 is a view showing the inside of a dryer according to an embodiment of the present invention.

3 is a view showing the inside of a first centrifugal force dust collector among centrifugal force dust collectors and centrifugal force dust collectors according to an embodiment of the present invention

4 is a view showing the inside of the first centrifugal force dust collector of the centrifugal force dust collector and the centrifugal force dust collector according to the embodiment of the present invention.

5 is a view showing a steam heating part according to an embodiment of the present invention.

6 is a view showing a chimney portion according to an embodiment of the present invention.

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

The circulating steam reheating sludge drying system of the present invention performs sludge drying and discharges the dry gas generated during sludge drying by exhausting dust and odors to the exhaust gas. Exchanges heat with the deodorizing gas to be discharged and is supplied as a heat source for drying the sludge. The odor is collected and supplied to the combustion air of the deodorization furnace by the first and second heat exchange with the exhaust gas. The heat generated during the drying of the sludge is recovered, .

1, the circulating steam reheating sludge drying system includes a dryer 100, a deodorization furnace 400, a steam heater 500, an exhaust blower 220, and a circulating blower 240. As shown in FIG.

The circulating steam reheating drying system further includes a centrifugal force dust collector 300, a preheater 600, a filter 700, an artificial blower 720, and a chimney 800.

The dryer 100 receives the sludge and dries moisture of the sludge as a heat source to form a sludge dried material.

Sludge is explained using sewage sludge as an example.

The sludge supplied to the dryer 100 has a moisture content of about 80%, and the dried sludge dried by the dryer 100 has a moisture content of 10% or less. The dryer 100 supplies the superheated steam of about 400 ° C as a heat source to dry the sludge and remove the moisture of the sludge dried with a high thermal efficiency.

The malodor contained in the sludge is discharged and included in the dry gas, and is removed while passing through the centrifugal force dust collector 300 and the deodorization furnace 400 to be described later.

The sludge is introduced into the sludge semi-entrant 10 and then stored in the sludge storage tank 20 and supplied to the dryer 100 through the supply pipe 30. The sludge can be continuously and constantly supplied into the dryer 100 through the feed conveyors 40 and 50 provided between the supply pipe 30 and the dryer 100. [

The dryer (100) has a multi-stage double paddle type drying structure and dries the sludge by a direct steam drying method.

As shown in FIG. 2, the dryer 100 has an internal space 111 capable of receiving sludge. The inner space 111 is divided into a plurality of drying chambers continuous by a plurality of partition walls 113. A plurality of drying chambers are provided with a paddle type conveying conveyor 115 for conveying and drying the sludge.

The paddle-type conveying conveyor 115 is shaped like a paddle screw, and the sludge is stirred and transferred while the paddle screw is rotated in the process of conveying the sludge from one side to the other side, so that drying is continuously performed and efficient drying is performed.

For example, although the dryer 100 of FIG. 2 has seven stages of drying chambers from the bottom to the top, in order to dry the sludge containing about 80% of moisture with the sludge containing about 10% of water, It may be efficient to provide a stage drying chamber.

The 9th stage drying room has 1 stage from the bottom, 2 stage ... 8th, and 9th, and the uppermost stage becomes the 9th stage and the lowermost stage becomes the 1st stage.

In this case, by setting the paddle angle of the paddle-type conveying conveyor 115 provided in the drying chambers 9 to 4 of the plurality of drying chambers to be small in the advancing direction of the sludge (about 10 ^° ), a large amount of sludge is pumped up, The time and area can be increased to allow the drying to proceed rapidly.

Also, in the 5th and 6th stages of the drying chambers, when the sludge is dried and the water content is about 55% ~ 45%, the sludge clumps together to cause gluing, so that the gluing phenomenon can be solved Remove the sludge quickly.

Therefore, when a dryer having a 9-stage drying chamber is applied, a variable speed driver (VVVF) can be installed only in the 5th and 6th stages.

The paddle type conveying conveyor 115 provided in the drying chambers in the lower first and second stages among the plurality of drying chambers minimizes the generation of dust by allowing the paddle screw to rotate at a low speed while conveying the sludge.

The dryer (100) has a sludge inlet (117) and a drying outlet (119). The sludge inlet 117 is connected to the drying chamber located at the uppermost one of the plurality of drying chambers for sludge introduction. The dry matter outlet 119 is located at the lowermost one of the plurality of drying chambers for discharging the dried sludge.

The dryer 100 includes a heat source inlet 121 for drying the sludge and a dry gas outlet 123 for discharging the dry gas generated while drying the sludge.

The heat source inlet 121 is formed to be connected to the drying chamber directly below the uppermost drying chamber among the plurality of drying chambers.

The drying chamber is dried by evaporation of moisture at each stage and maintained at 450 ° C to 120 ° C. The lowermost drying chamber discharges sludge dry matter at a moisture content of 10% or less.

The dryer 100 includes an oxygen concentration sensor 131 and a nitrogen gas purge unit 133. The oxygen concentration sensor 131 is installed inside the dryer 100 to detect the oxygen concentration. When the oxygen concentration detected by the oxygen concentration sensor 131 is equal to or higher than the set concentration, the nitrogen gas purge unit 133 purges the nitrogen gas into the drier 100 to suppress the fire.

The oxygen concentration sensor 131 is installed in the lowermost drying chamber to detect the oxygen concentration of the discharged superheated steam. The nitrogen gas purge section 133 may be installed in the drying chamber of each stage or may be installed to purge the nitrogen gas in the direction of the dry gas discharge port 123 at a position opposite to the dry gas discharge port 123 in consideration of the transport direction of the sludge .

If the oxygen concentration of the superheated steam detected by the oxygen concentration sensor 131 is equal to or higher than the preset concentration, it is determined that a fire has occurred.

When nitrogen gas is poured into the dryer 100 when a fire occurs, the internal space 111 is filled with nitrogen gas, which is an inert gas, and oxygen is pushed to the dry gas outlet 123 or the like, so that the fire can be suppressed.

A rotary valve 125 is installed in the dry matter discharge port 119. The rotary valve 125 is designed to discharge oxygen while shutting off the sludge dried matter.

A discharge conveyor 127 is connected to the rotary valve 125. The discharge conveyor 127 receives the dried sludge discharged from the rotary valve 125, and discharges the sludge.

A heat sink (140) is provided on the upper part of the dryer (100).

As shown in FIG. 1, the upper surface of the dryer 100 may be formed of a heat sink 140, heat recovered through the heat sink 140 may be recovered and the sludge may be supplied to the dryer 100 It can be used for preheating.

And a heat radiation recovery means 150 for recovering the heat of the heat radiation plate 140 to preheat the sludge.

The heat dissipating and collecting means 150 includes a circulation duct 151 formed in the heat dissipating plate 140 and a circulation duct 151 formed in a double pipe shape surrounding the outer circumferential surface of the supply pipe 30 for conveying the sludge to the dryer 100. [ And a pipe (153).

 One end of the circulation pipe 153 is connected to the inlet of the circulation duct 151 and the other side of the circulation pipe 153 is connected to the outlet of the circulation duct 151. Heat radiated through the heat sink 140 circulates through the circulation pipe 153 . The circulation pipe 153 may have a spiral shape so that heat can circulate on the outer circumferential surface of the supply pipe in a spiral form.

The heat radiation recovery means 150 further includes a heat radiation circulation blower 155 for securing a circulation force for circulating the heat of the heat radiation plate 140 through the circulation pipe 153.

On the other hand, it includes a transfer line 210 for transferring the dry-gas to the deodorization furnace 400.

A centrifugal force dust collector 300 is installed in the transfer line 210. The centrifugal force dust collector 300 is for collecting the dust contained in the dry gas and discharging it to the lower part.

A plurality of centrifugal force dust collectors 300 may be installed on the transfer line 210.

The centrifugal force dust collector 300 includes a first centrifugal force dust collector 310 for separating dust in the gasses being sucked by centrifugal force, and an electric dust collection device 300 for applying a high voltage while separating dust in the gasses being sucked by centrifugal force, And may include first and second electrical centrifugal force dust collectors 320 and 330.

The first centrifugal force dust collector 310 and the first and second electrical centrifugal force dust collectors 320 and 330 are connected to the first centrifugal force dust collector 320 and the second electric centrifugal force collector 330 ), Or to selectively pass either of them depending on the dust concentration.

3 and 4, the first and second electrical centrifugal force dust collectors 320 and 330 are respectively provided with dust concentration sensing units 311 and 321 for measuring the dust concentrations included in the carbon dioxide gas flowing through the centrifugal dust collector, .

It is possible to control whether or not the first electrostatic centrifugal force collector 320 and the second electrostatic centrifugal force detector 330 pass the carbon monoxide gas according to the dust concentration measured by the dust concentration detecting units 311 and 321. [

When the dust concentration contained in the carbon dioxide gas flowing through the first centrifugal force dust collector 310 is equal to or higher than the set value, the carbon dioxide gas passing through the first centrifugal force dust collector 310 is sequentially passed through the first and second centrifugal force dust collectors 320 and 330 do.

Alternatively, if the dust concentration contained in the carbonized gas passing through the first electrostatic centrifugal force collector 320 is equal to or higher than the set value, the carbonized gas does not pass through the first electrostatic centrifugal force dust collector 320 and passes through the second electrostatic centrifugal force dust collector 330 And water is sprayed to the electric dust collecting pole 325 of the first electrostatic centrifugal force collector 320 to clean and wait for the collected dust.

The dust concentration detecting units 311 and 321 may be laser detectors for detecting the dust pressure by irradiating a laser beam L to an upper outlet portion of the centrifugal force dust collector through which the dry gas is discharged.

As shown in FIG. 4, the first centrifugal force dust collector 310 includes a cyclone that separates the dust in the carbon monoxide gas sucked by centrifugal force downward.

As shown in FIG. 5, the first and second electrostatic centrifugal force collectors 320 and 330 include a first centrifugal force collector using a cyclone and an electrostatic centrifugal force collector for filtering fine particles.

The first and second electrostatic centrifugal force collectors 320 and 330 include a cyclone 323 for separating the dust in the carbon monoxide gas sucked in by the centrifugal force into a lower part and an electric motor 323 for attaching fine particles in the cyclone 323 using a high voltage, A dust collecting electrode 325 and a water spraying nozzle 327 for spraying water for cleaning the electric dust collecting electrode 325. [

When a discharge electrode (not shown) is disposed on both sides of the electric dust collecting electrode and the direct current voltage is applied to the discharge electrode, the first and second electric centrifugal force dust collectors 320 and 330 generate an unequal electric field between the electric dust collecting electrode and the electric dust collecting electrode, The molecules move to the positive electrode 325 and the dust is attached to the electrode 325.

The electric dust collecting electrode 325 has a plurality of protrusions 326 formed along the outer surface thereof. The protrusions 326 are formed to have a sharp point toward the tip to facilitate attachment of the fine particles. The protrusion 326 widens the surface area of the electrostatic dust collecting electrode 325 to facilitate attachment of fine particles.

By spraying water to the electric dust collecting electrode 325, dust attached to the electric dust collecting electrode 325 and the protrusion 326 can be cleaned to increase the collection efficiency and prevent re-scattering. The wastewater generated by the water spray can be collected and discharged smoothly by the lower outlet provided at an inclined angle.

The water spray nozzle 327 may be installed directly on the upper end of the dust collecting electrode 325 through an insulating material or on the upper wall of the first electrostatic centrifugal force collector 310.

One or two water spray nozzles 327 are provided for each of the electric dust collecting poles 325 so that water can be uniformly sprayed to the entire electrostatic dust collecting poles 325. In order to continuously supply water, And is connected to a water supply device provided outside the dust collector 300.

The first centrifugal force dust collector 310 is capable of collecting and removing only 30 μm or more, and it is difficult to collect fine particles of less than 30 μm. And further includes first and second electrical centrifugal force precipitators 320 and 330 for removing fine particles of less than 30 mu m contained in the dry gas.

As shown in FIG. 1, the apparatus further includes a circulation line 230 branched from a conveyance line 210 through which the carbon dioxide gas passed through the centrifugal force dust collector 300 is conveyed. The circulation line 230 is intended to circulate only the dry evaporated moisture of the dry gas without condensate generation in the deodorization furnace and circulate the remaining dry gas for energy recovery.

An exhaust blower 220 is installed in the transfer line 210. The exhaust blower 220 is controlled by the automatic damper 221 according to the pressure of the downstream of the dryer 100 to supply the deodorization furnace 400 with the carbon monoxide gas that has passed through the centrifugal force dust collector 300.

A circulating blower 240 is installed in the circulation line 230. The circulating blower 240 supplies the dry gas of the remaining transfer line 210 except for the dry gas discharged from the automatic damper 221 associated with the exhaust blower 220 to the steam heater 500 for heat exchange.

For example, 16.7% (or about 18%) of the dry gas passing through the centrifugal force dust collector 300 is supplied to the deodorization furnace through the air flow adjustment of the exhaust blower and the circulating blower, and the remaining 83.3% (or about 82%) The steam can be supplied to the heat through the circulation line. In this case, the exhaust blower air volume can be controlled to 5 m3 / min and the circulating blower air volume can be controlled to 25.7 m3 / min.

The exhaust blower 220 efficiently supplies the carbon monoxide gas to the deodorization furnace 400 only when moisture is evaporated. This causes a part of the dry gas containing moisture from which the fine particles (particulate matter) is removed to be burned in the deodorization furnace 400 with the combustion air so as to be oxidized at high temperature to be deodorized without generating condensed water.

The induction blower 720 receives a pressure signal from the deodorization furnace 400 and performs constant and energy efficient exhaust with the automatic damper 730, thereby maintaining the pressure in the deodorization furnace 400 constant to maximize the deodorizing effect.

The deodorization furnace 400 supplies the dry gas generated in the dryer 100 through the transfer line 210 and burns it to remove moisture and odor components contained in the dry gas. The dry gas is subjected to a high-temperature oxidation treatment at about 800 to 850 ° C in the deodorization furnace (400) to remove all moisture and odor components contained in the dry gas. Therefore, the deodorizing gas discharged from the deodorization furnace 400 does not contain moisture and odor components.

The deodorizing gas discharged from the deodorization furnace (400) flows into the steam heater (500). The steam heater 500 performs heat exchange with the deodorizing gas at a high temperature and the low-temperature dry gas supplied through the circulation line 230.

5, the steam heater 500 is connected to a low-temperature dry gas (about 120 DEG C) supplied through the circulation line 230 to a high-temperature deodorizing gas (about 850 DEG C) discharged from the deodorization furnace 400, ) Is heated to approximately 400 캜 through heat exchange. The dry gas that has been heat-exchanged in the steam heater 500 is supplied to the dryer 100 as a heat source.

The use of energy for drying the sludge is minimized by heat-exchanging the dry-gas (circulating steam) discharged from the dryer 100 with the deodorizing gas discharged from the deodorization furnace 400 and supplying it as a heat source to the dryer 100.

Also, since the deodorizing gas is a gas from which dust and odors are removed, clogging of the heat exchange pipe in the steam heater 500 is prevented, thereby extending the life of the steam heater and increasing the heat exchange efficiency.

As shown in FIG. 1, the apparatus further includes a filter 700 for removing ultrafine dusts of deodorized gas discharged from the steam heater 500 with a filter. The filter and dust collector 700 removes ultrafine dust from the deodorizing gas discharged from the steam heater 500 and discharges the deodorized gas. The filter may be a filter medium or a filter cloth, and ultrafine dust contained in the deodorizing gas is filtered while the deodorizing gas passes through the filter medium or the filter cloth.

The exhaust gas discharged from the filter dust collector 700 is discharged to the outside through the chimney 800. The filter and dust collector 700 is connected to the chimney 800 and the discharge line 710 and the discharge line 710 is provided with a blower 720 for smoothly discharging the exhaust gas.

A double pipe is installed inside the chimney heat insulating material when the exhaust gas discharged from the filter dust collector 700 passes through the chimney 800 and the odor gas collected in the sludge returning area 10, the sludge storage tank 20, the drier 100, Circulates from the top of the chimney 800 to the bottom, thereby heating the odor gas, and supplying the heated odor gas to the deodorization furnace 400 as combustion air.

As shown in FIG. 6, the double pipe provided in the chimney 800 is a transfer pipe 810. The transfer pipe 810 has a double pipe shape surrounding the outer circumferential surface of the chimney and transfers the odor gas collected at the sludge returning area 10, the sludge storage tank 20, the drier 100 and the like to the lower part of the chimney, ) Of the exhaust gas.

The transfer pipe 810 has a spiral shape so that odorous gas is circulated and circulated from the top of the chimney 800 to the bottom. The transfer pipe 810 is connected to the exhaust pipe 810 through which the odor gas inlet 811 is located on the upper side of the chimney and the outlet 813 of the odor gas is located on the lower side of the chimney 800, To be more efficiently heated by heat.

A preheater (600) is further installed between the steam heater (500) and the filter (700). The preheater 600 is connected to the transfer pipe 810 through the odor gas transfer line 820.

The preheater 600 heats the odor gas heated first while passing through the transfer pipe 810 through the heat exchange with the deodorizing gas discharged from the steam heater 500, Gas to the combustion air.

Since the collected odor gas is supplied to the combustion air of the deodorization furnace 400 after the first and second heat exchange with the exhaust gas, the combustion energy can be saved to the maximum by deodorization.

Hereinafter, the operation of the present invention will be described.

The circulating steam reheating sludge drying system of the present invention performs sludge drying and discharges the dry gas generated during sludge drying by discharging dust and odors by exhaust gas.

The sludge drying is performed by a heat source (heated steam of about 400 ° C. reheat the circulating steam) in a process of transferring the sludge supplied in a predetermined amount to the dryer 100 from the uppermost drying chamber to the lowermost drying chamber in the multi- In this process, the paddle-type conveying conveyor 115 for conveying and drying the sludge conveys the sludge while stirring, thereby performing the continuous drying, and the residence time of the sludge in the dryer 100 is increased, so that the drying of the sludge can be performed more efficiently have.

The sludge supplied to the dryer 100 has a moisture content of about 80%, and the dried sludge dried and dried in the dryer 100 has a moisture content of about 10% or less. Moisture control of the sludge dried from the dryer 100 is possible.

The dryer (100) has a closed structure to prevent the spread of odors and to collect dust easily. The dried sludge is discharged to the discharge conveyor 127 through the rotary valve 125 and discharged while being cooled at the discharge conveyor 127. The dried sludge dried material is in a state in which water is removed, so that it is easy to carry and odor is not generated.

The dryer 100 purges the inside of the dryer 100 with nitrogen gas to fill the inside space 111 with nitrogen gas as an inert gas and oxygen is pushed to the dry gas outlet 123 or the like so that fire is prevented .

The dry gas generated in the drying process of the sludge in the dryer 100 is discharged through the dry gas discharge port 123 and then discharged through the transfer line 210 connected to the dry gas discharge port 123 into the first centrifugal force collector 310, and the dust contained in the dry gas is removed while passing through the first and second electrostatic centrifugal force collectors 320, 330.

As the dry gas passes through the first centrifugal force dust collector 310, dust of 30 μm or more is removed, and fine particles of less than 30 μm can be removed while passing through the first and second centrifugal force dust collectors 320 and 330.

In this process, whether or not the first electrostatic centrifugal force collector 320 and the second electrostatic centrifugal force collector 330 pass through the dry gas is controlled according to the dust concentration measured by the dust concentration detectors 311 and 321 of the first electrostatic centrifugal force collector 320 .

For example, if the dust concentration contained in the carbonized gas passing through the first electrostatic centrifugal force collector 320 is equal to or greater than the set value, the carbon dioxide gas does not pass through the first electrostatic centrifuge 331, And water is sprayed to the electric dust collecting pole 325 of the first electrostatic centrifugal force dust collector 320 to clean and wait for the collected dust.

A portion of the dry gas having passed through the centrifugal force dust collector 300 and from which dust and fine particles have been removed is supplied to the deodorization furnace 400 without the condensate (generation of waste water), and the remainder is supplied to the steam heater 500 .

The ratio of the carbon monoxide gas supplied to the deodorization furnace 400 to the carbon monoxide gas supplied to the steam heater 500 is determined by the ratio between the exhaust gas blower 220 installed in the transfer line 210 connected to the deodorization furnace 400, The circulation line 230 is connected to the circulation line 240 and the circulation line 240 is connected to the circulation line 230.

16.7% (or about 18%) of the carbon monoxide gas passed through the centrifugal force dust collector 300 is supplied to the deodorization furnace 400 while the air volume of the exhaust blower is controlled to 5 m3 / min and the air volume of the circulating blower is controlled to 25.7 m3 / And the remaining 83.3% (or about 82%) can be supplied to the steam heater 500 through the circulation line 230.

The dry gas supplied to the deodorization furnace 400 is combusted with combustion air to remove odors and moisture. The temperature of the deodorization furnace 400 is maintained at 800 to 850 ° C to facilitate removal of odor and moisture.

After the deodorizing furnace 400 has been exhausted from the deodorization furnace 400, the carbon monoxide gas, i.e., deodorized gas from which odor and moisture have been removed from the deodorization furnace 400 is sequentially passed through the steam heater 500 and the preheater 600 for heat recovery, And the ultra-fine tenant is removed while passing through the filter dust collector. The deodorized gas from which the super fine tenant is removed is discharged to the outside through the blower 720 and the chimney 800 by the exhaust gas.

The exhaust gas finally discharged through the chimney 800 passes through the centrifugal force dust collector 300 and dust and fine particles are removed and the water and the odor are removed while passing through the deodorization furnace 400 and passed through the filter 700 While minimizing air pollution since the micro-tenant has been removed.

The deodorized gas discharged from the deodorization furnace 400 is heated to about 850 ° C. and is used for reheating the carbon monoxide gas supplied to the steam heater 500 through the circulation line 230.

As shown in FIG. 5, the high temperature deodorizing gas at about 850 DEG C is heat-exchanged with the low temperature carbonized gas of about 120 DEG C while passing through the steam heater 500, thereby heating the carbonized gas to about 400 DEG C. The dry gas, which has been reheated to about 400 ° C. while passing through the steam heater 500, is supplied to the dryer 100 as a heat source for drying the sludge, thereby enabling energy to be efficiently treated.

The malodor gas generated in the sludge semi-admission unit 10, the sludge storage tank 20, the dryer 100 and the like is collected and supplied to the combustion air of the deodorization furnace 400 by the first-order heat exchange with the deodorizing gas and the exhaust gas.

The deodorizing gas that has passed through the steam heater 500 has a high temperature of about 250 ° C, and thus is used for reheating the combustion air supplied to the deodorization furnace 400. The combustion air supplied to the deodorization furnace 400 uses the odor gas collected in the sludge returning area 10, the sludge storage tank 20, and the drier 100 by using a duct or the like.

The odor gas collected in the sludge semi-admission chamber 10, the sludge storage tank 20 and the dryer 100 passes through the transfer pipe 810 formed in the chimney 800 from the upper part to the lower part, And is secondarily heated by heat exchange with deodorizing gas at about 250 DEG C while passing through the preheater 600 and then supplied to the deodorization furnace 400 as combustion air.

Since the odor gas supplied to the deodorization furnace 400 is supplied after being heated to a high temperature of about 400 DEG C by the exhaust gas and the deodorizing gas, the amount of the fuel (for example, LNG gas) And the energy efficiency can be increased.

Heat generated during sludge drying is recovered and used as sludge preheating means.

The circulation pipe 153 is formed so as to surround the outer circumferential surface of the supply pipe 30 for transferring the sludge to the dryer 100 and the heat dissipated through the heat dissipation plate 140 is circulated through the circulation pipe 153 do. Accordingly, the preheated sludge is supplied into the dryer 100 in the process of being transported through the supply pipe 30, so that the energy efficiency of the dryer can be increased.

Table 1 below shows the test results of the calorific value and the components of the dried sludge by supplying sludge to the dryer according to the embodiment of the present invention.

Sample name: Sewage sludge dried material + MDF milled material Mixed molding

Test Items	unit	result	Analysis method
Shape and Size		%	100	Solid fuel test standard
Low calorific value	kcal / kg	3570	Solid fuel test standard
moisture	wt%	6.44	Solid fuel test standard
Ash	wt%	27.89	Solid fuel test standard
Goat	wt%	0.247	Solid fuel test standard
Soot	wt%	2.351	Solid fuel test standard
Mercury	mg / kg	0.3212	Solid fuel test standard
cadmium	mg / kg	Non-detection	Solid fuel test standard
lead	mg / kg	52.778	Solid fuel test standard
arsenic	mg / kg	Non-detection	Solid fuel test standard

[Testing institute: Wonil Chemical Co., Ltd. Environment]

According to Table 1, the sludge dried material has a high calorific value of 3570 kcal and a low water content of 6.44 wt%, which can be used as a fuel. The amount of chlorine, sulfur, mercury, cadmium, lead and arsenic is small or not detected. It can be minimized.

In the present invention, the sludge is efficiently dried using a multi-stage dryer and an oxygen concentration sensor is installed in the dryer to automatically purge nitrogen gas when a fire hazard is detected, thereby preventing a fire.

In addition, since the circulating duct is formed in the heat radiating plate at the upper part of the dryer, the temperature of the sludge supplied to the dryer is increased by circulating air to be radiated, so that the energy efficiency can be increased.

In addition, the dried sludge dried in the dryer can be cooled and discharged safely from the risk of fire because the oxygen is blocked by the rotary valve and is cooled during discharge through the discharge conveyor.

In addition, since the dry gas discharged from the dryer passes through the first centrifugal force collector, the first and second electric centrifugal force collectors, the major dust and the fine particle dust are removed, and the steam passes through the heat exchanger. The heat exchange efficiency of the steam heat can be increased.

Further, dust concentration sensing units may be provided at the outlet of the first centrifugal force collector and the first and second centrifugal force precipitators to detect the particle concentration and particle size separation, performance confirmation, and clogging of the first centrifugal force collector, And the centrifugal force dust collector can be efficiently used.

In addition, since the low-temperature dry gas generated from the dryer is controlled by the automatic dampers in response to the downstream pressure of the dryer, the dry gas is efficiently transferred to the deodorization furnace only when the moisture is evaporated.

In addition, the odor and moisture contained in the dry gas are all removed from the deodorization furnace, and the ultrafine dust is removed after passing through the filter and dust collector, and then discharged as exhaust gas, so that odor does not occur and does not cause environmental pollution.

In addition, the deodorizing gas discharged from the deodorization furnace circulates the surplus dry gas through the heat exchange in the steam heat exchanger and circulates it to the dryer heat source, thereby optimizing the dryer energy efficiency.

In addition, the energy efficiency of the deodorization furnace can be optimized by supplying the combustion air to the deodorization furnace after the first and second heat exchanges the odor gas with the deodorization gas passing through the steam heater and the exhaust gas passing through the chimney .

Since the circulating steam reheating sludge drying system described above is a closed circulating system, it can maintain high thermal efficiency, does not generate odor, is easy to operate, and has a low maintenance cost.

The above-mentioned circulating steam reheating sludge drying system is capable of drying sludge of more than 4.16 ton / hr (100 ton / day).

Since the sludge is dried in the sealed multi-stage dryer and the dry gas, the heat source, and the odor gas are closed circulated, the sludge can be efficiently dried, the sludge can be dried efficiently, And maintenance cost is low.

In addition, the present invention is capable of preserving the environment around the sludge treatment facility and preventing the occurrence of complaints because there is no odor generated due to the high-temperature oxidation treatment of the odor, sludge return odor, and sludge storage odor generated in the sludge drying process There is an effect that can be.

Claims (6)

1. A dryer for receiving sludge and drying the moisture of the sludge with a heat source to form a sludge dried material;

   A deodorizing furnace for supplying the dry gas generated in the dryer through a transfer line and burning the moisture to remove moisture and odor components contained in the dry gas;

   A steam heating unit for heating the dry gas supplied through the circulation line branched from the transfer line with the deodorizing gas discharged from the deodorization furnace through heat exchange and supplying the dry gas to the dryer as a heat source;

   An exhaust blower installed on the conveying line and controlled by an automatic damper according to a pressure of a downstream end of the dryer to supply the dry gas to the deodorization furnace; And

   A circulation blower installed in the circulation line for supplying the remaining dry gas to the steam heater, the dry gas being removed from the exhaust blower by a moisture evaporation amount;

   Lt; / RTI >

   And a centrifugal dust collector installed in the transfer line for collecting dust contained in the carbonized gas and discharging the dust to the lower part and supplying the odorous component to the deodorizing furnace,

   The centrifugal force dust collector

   A first centrifugal force dust collector for separating dust in the drawn-in gas by centrifugal force,

   And first and second electrostatic centrifugal force collectors for performing electrostatic dust collection by applying a high voltage while separating dust in the gas stream drawn by centrifugal force,

   The first centrifugal force collector, the first centrifugal force collector and the second centrifugal force collector sequentially pass the first centrifugal force collector and the second centrifugal force collector after passing the first centrifugal force dust collector, Wherein the sludge is connected so as to selectively pass through the sludge drying system.
2. The method according to claim 1,

   The first centrifugal force collector, the first and second centrifugal force centrifugal force collectors

   A dust concentration sensing part for measuring the concentration of dust contained in the carbon dioxide gas flowing through the centrifugal force dust collector is provided at the upper outlet part,

   Wherein the first electrostatic centrifugal force collector and the second electrostatic centrifugal force collector are controlled to pass through the dry gas according to the dust concentration measured by the dust concentration detecting unit.
3. The method according to claim 1,

   The first and second electrostatic centrifugal force collectors

   A cyclone for separating the dust in the carbon monoxide gas sucked by centrifugal force into a lower part,

   An electrostatic dust collecting pole for attracting fine particles in the cyclone using a high voltage,

   And a water spray nozzle for spraying water onto the electric dust collecting electrode.
4. A dryer for receiving sludge and drying the moisture of the sludge with a heat source to form a sludge dried material;

   A deodorizing furnace for supplying the dry gas generated in the dryer through a transfer line and burning the moisture to remove moisture and odor components contained in the dry gas;

   A steam heating unit for heating the dry gas supplied through the circulation line branched from the transfer line with the deodorizing gas discharged from the deodorization furnace through heat exchange and supplying the dry gas to the dryer as a heat source;

   An exhaust blower installed on the conveying line and controlled by an automatic damper according to a pressure of a downstream end of the dryer to supply the dry gas to the deodorization furnace; And

   A circulation blower installed in the circulation line for supplying the remaining dry gas to the steam heater, the dry gas being removed from the exhaust blower by a moisture evaporation amount;

   Lt; / RTI >

   A filter for removing ultrafine dusts of deodorized gas discharged from the steam by a filter;

   A chimney for discharging the exhaust gas passed through the filter and dust collector to the outside,

   A transfer pipe which is formed in a double pipe shape surrounding the outer circumferential surface of the chimney and transfers the odor gas collected at one or more of the sludge storage tank, ,

   And a preheater for supplying the deodorizing furnace with the deodorizing furnace by supplying the deodorizing gas to the deodorizing furnace by heating the deodorizing gas, Sludge drying system.
5. 5. The method of claim 4,

   Wherein the inside of the transfer pipe is formed in a spiral shape so that the malodor gas is circulated and circulated from the upper part of the chimney to the lower part to be heated.
6. 5. The method of claim 4,

   The dryer

   An inner space capable of receiving the sludge,

   A plurality of partition walls dividing the internal space into a plurality of continuous drying chambers,

   A paddle type conveying conveyor installed in the plurality of drying chambers for conveying the sludge,

   A sludge inlet connected to a drying chamber located at a top end of a plurality of drying chambers for sludge introduction,

   A drying agent discharge port positioned at the lowermost one of the plurality of drying chambers for discharging the dried sludge,

   A heat source inlet for drying the sludge,

   And a dry gas outlet for discharging the dry gas generated while drying the sludge.

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