KR20080047246A - The sludge drying method and machine using heat transfer oil - Google Patents

Abstract

A method and an apparatus for drying sludge using a heat transfer oil are provided to dry organic sludge environmentally friendly and economically, recover the entire heat transfer oil while drying the sludge completely, utilize heat value of the organic sludge as regenerated energy, and recover energy while preventing odor of water vapor exhausted in the drying process. An apparatus for drying sludge using a heat transfer oil comprises: a sludge-oil mixer(10) for mixing sludge with the heat transfer oil to produce a mixture; an evaporator(20) for receiving the mixture from the sludge-oil mixer and drying the mixture; a vaporizer(30) for receiving the mixture from the evaporator and vaporizing the heat transfer oil in a vacuum state; a condenser(40) for condensing water vapor evaporated from the evaporator; and an oil recovering machine(50) for condensing the vaporized heat transfer oil to recover the heat transfer oil. The evaporator includes a flat heat plate(21), an injector(22) for injecting the mixture onto the heat plate, and a conveyor(23) for conveying the mixture on the heat plate, the evaporator being sealed. The conveyor is a wire mesh conveyor. The apparatus further comprises an oil boiler(60) for heating the oil, wherein the oil heated in the oil boiler is sent to the evaporator and the vaporizer through a distributor(61) connected to the oil boiler such that the oil is recovered to the oil boiler after supplying heat to the evaporator and the vaporizer.

Description

Sludge drying method and apparatus using heat transfer oil {THE SLUDGE DRYING METHOD AND MACHINE USING HEAT TRANSFER OIL}

1 is a block diagram of an embodiment of the present invention.

2 is a block diagram of another embodiment of the present invention.

3 is a partially cutaway perspective view of the evaporator of the present invention.

The present invention relates to a sewage sludge drying method and apparatus for environmentally and economically drying sewage sludge.

Organic sludge from sewage treatment plants and livestock complexes has high water content and high odors, and many of them are wastes that cause secondary environmental pollution if left untreated. In Korea, most of the organic sludge is treated by ocean dumping in the sea, and the amount is rapidly increased from 1.70 million tons in 1990 to 7.1 million tons in 2000 and 9.993 million tons in 2005. Organic sludge has valuable heat as renewable energy, but it is worth using as renewable energy. However, their water content is too high and the current technology does not dry well. The situation is dumping at sea.

To utilize the heat of organic sludge, it is necessary to dry the sludge. The conventional sludge drying technology is classified into a direct drying method in which the sludge is dried directly with combustion air, and the hot plate is heated by the heat of combustion to contact the sludge to dry the sludge. It is divided into indirect drying method. The direct drying method is advantageous in terms of thermal efficiency and simpler installation than the indirect drying method because the sludge is directly contacted and dried in the hot combustion gas, but this method generates odor during drying and dust is discharged with the combustion gas to remove them. There is a need for large-scale treatment facilities. In the indirect drying method, on the other hand, the combustion gas heats the heating medium first, and when the heating medium heats the hot plate such as the drying tank or disk again, the sludge is indirectly supplied with the thermal energy from the hot plate to dry the passage of the combustion gas and the dry matter. It can be separated to prevent odors and dusts and to control the drying rate, but this method has high drying cost and low fuel cost.

Currently, 250kg of oil is used to dry 1 ton of sludge in the direct drying method, which is about 2,700,000 Kcal, which is about 5.4 times the net calorific value of 500,000Kcal, and the heat efficiency is only 18.5%. 700,000 Kcal The reason for this low sludge drying efficiency is that heat is not transferred to the inside of the sludge. For example, in the case of sludge that is in contact with a heated hot plate of 400 ° C. or higher, the contact surface with the hot plate rapidly heats up to a temperature of 100 ° C. However, from this time, the vaporization of moisture starts and the temperature is maintained at 100 ° C until all the moisture on the contact surface evaporates, so that the hot plate and the sludge contact surface form a temperature discontinuity surface, which prevents heat energy from being transferred into the sludge. The dried sludge forms an air layer and prevents heat transfer from the hot plate to the inside of the sludge by strong heat insulation action, and even though the hot plate is overheated and burned by this temperature discontinuity and the air layer heat action, the sludge inside cannot be transferred to the heat energy. In order to solve this problem, an extreme partial drying phenomenon is maintained. In order to solve this problem, even when the sludge is forcibly stirred, the temperature discontinuity surface and the air layer insulation action continue to occur at the contact surface of the sludge with the hot plate, thereby greatly reducing the drying efficiency.

Existing drying methods do not technically overcome the drying characteristics of the sludge, so the drying efficiency is very low, so it takes a long time to dry, and it takes a lot of fuel cost, and it requires large facility investment cost by raising the scale to supplement the low efficiency. Complaints are generated due to excessive odors. Until now, organic sludges have not been effectively dried, so they cannot use the calorie content of organic sludges at all.

Therefore, the present invention has the following technical problem to solve the above problems.

It is an object of the present invention to develop a new drying technology capable of overcoming the temperature discontinuous surface and air layer insulation effect generated in the drying of sludge. Accordingly, in the present invention, it is possible to economically dry organic sludge economically by devising a new heat transfer technology that does not occur the temperature discontinuity surface and air layer insulation action to significantly improve the low drying efficiency of the conventional drying method in organic sludge drying To provide a process.

To this end, in the present invention, to prevent the temperature discontinuity of the sludge drying and the thermal insulation of the air layer, the sludge is completely mixed with the heat transfer oil, which is a heat transfer catalyst, in the sludge to completely dry the sludge, and the new sludge recovers the entire amount of the catalyst material from the dried sludge. It is a technical problem to provide a drying method, and to provide an efficient sludge drying apparatus which is environmentally friendly and economically feasible.

On the other hand, when the sludge and oil are mixed, the sludge drying process proceeds well because the heat transfer efficiency increases. In this case, if the oil used as a catalyst is not fully recovered, the treated sludge is contaminated with oil and cannot be disposed of by landfill or ocean dumping. When the sludge is dried, water, which accounts for 80% of the sludge, evaporates, only oil remains, and in the latter stages, the sludge is dried in the heat transfer oil, and water vapor is not discharged well. And the remaining water remains in the sludge, and incineration of the remaining water remaining in the sludge absorbs the thermal energy and lowers the combustion temperature, resulting in the generation of pollutants due to incomplete combustion. The sludge will be completely dried As heat transfer oil is also both need a way to recover the device. It is therefore an object of the present invention to provide such a method and apparatus.

In addition, the present invention is configured to increase the energy efficiency of the system to use less heat than recovered heat to utilize the heat of the organic sludge as a renewable energy, and to recover energy while preventing the odor of water vapor emitted during the drying process It is an object to provide a renewable energy process. Accordingly, it provides a technology that recovers energy by using environmentally friendly steam to prevent odors and dusts from occurring during the drying process, and utilizes dried organic sludge as renewable energy.

In addition, the present invention is to configure the device so that all the facilities and devices for realizing the technical problem as described above can be continuous and automated to develop and install this sludge drying device to be easily installed, to prevent noise dust and odor It is an object of the present invention to provide a sludge drying apparatus that does not cause civil complaints in the sludge drying process.

First, strong heat transfer has to proceed for a long time to dry the sludge with high water content.When the sludge is transferred to heat energy, the physical properties change, such as volume decrease and rigidity, so that the sludge can be stably dried under these conditions. Evaporator must be developed.

To this end, a hot plate for supplying a large amount of drying energy necessary for drying the sludge, a sludge injector for placing a mixture of sludge and heat transfer oil on a hot plate, a moving device for continuously supplying a new mixture while heating and drying the mixture placed on the hot plate, And it provides a discharge device for discharging the mixture is dried to change the physical properties to the outside of the evaporator in detail.

In particular, the present invention provides a hot plate which is the core of the drying device as a device for supplying the heat energy required for sludge drying as a device capable of fast and continuous heat transfer to the sludge and heat transfer oil mixture, and also of the drying rate generated in the sludge drying process It provides a hot plate and a moving device that maintain its function without being deformed or overheated even with changes.

In addition, in the present invention, when the heat transfer oil and the sludge mixture is dried, the water, which occupies 80% of the original sludge, evaporates and the oil remains as it is, the sludge boils in the heat transfer oil in the latter part of the drying, resulting in an oil bubble. It is an object of the present invention to provide an apparatus for appropriately controlling the oil bubbles, since the drying is stopped because the efficiency of the oil is lowered and the condensate is contaminated by flowing out of the evaporator.

In addition, the sludge drying apparatus in the present invention is operated at high temperature and high pressure, the thermal deformation and thermal stress caused by the temperature change inside the drying apparatus during stop or operation, and also the physical properties of the soft sludge is hardened as the sludge drying proceeds. The present invention provides an apparatus capable of implementing a sludge drying method using heat transfer oil in response to such changes in general conditions.

Finally, the present invention is to provide a catalyst material recovery method and apparatus for recovering energy while recovering and reusing the expensive heat transfer oil used as a heat transfer catalyst for sludge drying so as not to be lost or altered, thereby improving thermal efficiency. .

The present invention has the following configuration to solve the above technical problem.

The present invention relates to a sludge drying method using a heat transfer oil, a mixing step of mixing a heat transfer oil having a boiling point higher than water and having a low vapor pressure with a sludge to form a mixture, and heating the mixture to heat the heat transfer oil as a heat transfer catalyst. Difference in the vapor pressure of water and oil, including a drying step of removing the moisture of the mixture to dry the mixture, and heating the mixture to vaporize the heat transfer oil to recover the heat transfer oil to condense and recover the heat transfer oil. It is configured to characterize the sludge using.

In addition, the process of evaporating the water and oil of the mixture is separated into the drying step of evaporating the water and the recovery step of evaporating the oil, respectively to maintain the temperature and pressure in a closed container, the water in the drying step After extracting preferentially it was configured to extract the oil in the recovery step.

In the evaporation process of the water and oil is configured to be filled with only steam and oil vapor in the sealed container, the drying step of the mixture is configured to be heated on a flat hot plate so that the oil does not collect.

The mixture is characterized in that the mixing ratio of the sludge and the continuous transfer oil is 1: 0.5 ~ 1: 0.8, the heat transfer oil is characterized in that the vapor pressure is a liquid of 1/10 level than the vapor pressure of water, the heat transfer oil is The vaporization point is configured to be characterized by petroleum at around 200 ° C.

In addition, the drying method of the present invention may further comprise a steam condensation step of producing a clean steam by condensing the steam generated in the drying step.

On the other hand, the present invention relates to a sludge drying apparatus using a heat transfer oil, a sludge-oil mixer 10 for producing a mixture by mixing the sludge and heat transfer oil, and the evaporator to receive the mixture from the sludge-oil mixer to dry 20, a vaporizer 30 which receives the mixture from the evaporator and vaporizes the heat transfer oil in a vacuum state, a condenser 40 which condenses water vapor evaporated from the evaporator, and condenses the vaporized heat transfer oil. It is configured to include an oil recovery unit 50 to recover.

With reference to the drawings to be described in more detail through an embodiment of the present invention. 1 is a configuration diagram of one embodiment of the present invention, Figure 2 is a configuration diagram of another embodiment of the present invention, Figure 3 is a partial cutaway perspective view of the evaporator of the present invention.

In the sludge drying method of the present invention, a heat transfer oil having a higher boiling point than water and having a vapor pressure of about 1/10 is introduced as a heat transfer catalyst. When heated to a temperature above 100 ℃, which is the boiling point of water, the sludge water vaporizes rapidly at high vapor pressure, but the heat transfer oil does not evaporate well at low vapor pressure at the same temperature, so it remains liquid and keeps heat transfer. .

Therefore, when the heat transfer oil is mixed with the sludge and put into the evaporator 20 to proceed with heat transfer in the horizontal hot plate in the evaporator, the heat transfer oil is quickly and sludged from the hot plate to the sludge by preventing the occurrence of thermal discontinuity and thermal insulation between the hot plate 21 and the sludge. Ensure constant heat transfer. In addition, if the thickness of the mixture on the hot plate is kept thin and uniform, the oil bubbles do not overflow and the sludge is completely dried, and after drying, the oil bubbles disappear.

When the dried mixture is put into a vacuum vaporizer 30 and heated, only 1/9 of the vaporization energy of water having a vaporization energy of 60 kcal / kg and 540 kcal / kg is used. Heat recovery from oil return to oil through heat exchanger and discharge only dried sludge

In other words, in the drying method of the present invention, the vapor pressure of the water to be dried and the vapor pressure of the heat transfer oil, which is a heat transfer catalyst, have a significant difference of about 10 times, and the evaporator and the vaporizer are vacuumed by using different points with a boiling point of about 100 ° C. and 200 ° C. Make sure there is no air, then evaporate the water in the evaporator and vaporize the oil in a separate carburetor.

In more detail, the mixture produced by mixing the organic sludge having a water content of 80% at an appropriate ratio with the heat transfer oil is placed on the flat hot plate 21 by using the wire mesh conveyor 24 and the injection barrel 27. Good fluidity makes the structure close to the hot plate and high heat conduction, so the heat energy is rapidly supplied from the hot plate to the mixture.

When the temperature of the contact surface between the mixture and the hot plate reaches 100 ° C., the moisture contained in the sludge of the contact surface starts to vaporize, but the heat transfer oil mixed in the sludge has a high boiling point, does not vaporize, and maintains a liquid state so that the temperature rises. It acts as a heat transfer catalyst to quickly transfer the heat energy into the mixture.

As a result, the temperature inside the mixture is gradually increased, so that temperature discontinuities of the mixture do not occur, and thermal energy is continuously transferred into the mixture through the heat transfer oil.

In addition, when the heat transfer oil inside the mixture is heated, the sludge temperature around it also reaches 100 ° C., so that vaporization proceeds, and vaporization of water vapor contained in the sludge proceeds much faster than the contact surface with the hot plate. Drying proceeds. In addition, since the heat transfer oil is evenly mixed, heat energy is transferred to the entire mixture, and vaporization of water vapor continues.

In addition, due to the vaporization of water vapor, when the space occupied by the original water becomes empty, heat transfer oil enters to fill the empty space, and the thermal efficiency of the hot plate and the mixture is maintained continuously so that thermal insulation does not occur, thereby greatly improving drying efficiency. Even though drying proceeds, the heat transfer oil has a vapor pressure lower than that of water so that it remains as a liquid without vaporization. Therefore, heat transfer is continuously performed without generating empty spaces that can insulate until complete drying.

The use of heat transfer oil as described above can significantly improve the drying efficiency of the sludge. Furthermore, when the organic sludge recovered by the drying method is incinerated, the organic sludge having a water content of 80% can be completely dried only by the amount of heat retained by the dried organic sludge, and the recovered high temperature dry sludge is also used as a fuel for a boiler through an incinerator. Can be used.

In addition, if the drying efficiency is high, a large amount of water vapor is continuously generated. If the water vapor is condensed in a confined state in a confined state to recover the condensate from the condenser, the energy of the generated water vapor can be recovered as clean steam. Has an effect.

In order to perform the heat transfer oil as a catalyst for sludge drying, the heat transfer oil must be kept in a liquid state in which water is completely vaporized. Therefore, a fuel oil having a higher vaporization point than 100 ° C., which is a one-pressure vaporization point of water, a significantly lower vapor pressure than water at a vaporization temperature of water, and a small vaporization energy is used for easy recovery later. Preferably, the 1 atm vaporization point is suitable for petroleum at about 200 ° C., and it can be seen by referring to Table 1 showing the vapor pressure of the temperature of the petroleum and water.

Pressure (kg / ㎠) Temperature (℃) oil water 21.11 0.00288 0.025 26.27 0.00394 0.033 32.22 0.00527 0.047 37.78 0.00696 0.065 43.33 0.00914 0.085 48.89 0.01181 0.116 54.44 0.01526 0.148 60.00 0.01947 0.197 65.56 0.02461 0.250 71.11 0.03093 0.322 76.67 0.03853 0.407 82.22 0.04774 0.510 87.78 0.05871 0.634 93.34 0.07178 0.792 98.90 0.08725 0.961 104.45 0.10546 1.200 110.01 0.12669 1.500 115.56 0.15144 1.800 121.12 0.18012 2.100 126.68 0.21324 2.500 132.23 0.25120 3.000 137.79 0.29472 3.500 143.34 0.34422 4.100 148.90 0.40037 4.700

The sludge and heat transfer oil are mixed in a weight mixing ratio of 1: 0.5 to 1: 0.8. When the weight mixture ratio of sludge and heat transfer oil falls below 1: 0.4, the oil becomes less and heat transfer is not good, and fluidity decreases, making injection into the evaporator difficult. A large amount of oil results in better heat transfer, but more residual oil after drying, which increases the amount of oil foaming and increases the amount of oil to be recovered. Accordingly, even when the weight ratio of sludge and oil is 1: 1, there is no problem in the drying effect, but the ratio is 1: 0.8 because the oil is excessive.

When the sludge is dried using the heat transfer oil, a large amount of water vapor is continuously generated by rapid heat transfer. If the water vapor is not mixed with other air in an enclosed space, it is rapidly condensed in a connected condenser to strongly transmit heat energy. do. Accordingly, the sludge steam of about 120 ° C. 2 atm generated in the evaporator 20 is condensed in the connected condenser 40 to become condensed water, thereby producing clean water vapor having a pressure of 1 ° C. at 100 ° C. through heat exchange.

In addition, the mixture of the water-evaporated sludge and the heat transfer oil vaporizes all of the heat transfer oil on the hot plate while maintaining a vapor pressure of 120 ° C. and 0.18 atm in a closed space of the vaporizer 30. The vaporized heat transfer oil is condensed and recovered in the connected double tube injector 80, and the heat energy of the oil vapor causes the cold sludge mixture inside the injector to be heated and fed to the evaporator.

As described above, the present invention provides a method of drying the sludge by separating the heat transfer oil and the sludge dry matter, reusing the heat transfer oil and discharging the sludge dry matter into a separate container device while maintaining the vacuum of the vaporizer.

Sludge drying apparatus using the sludge drying method as described above has the following embodiment.

As shown in FIG. 1 and FIG. 2, a sludge-oil mixer 10 for mixing a sludge and a heat transfer oil to produce a mixture, and an evaporator 20 for receiving and drying the mixture from the sludge-oil mixer. And a vaporizer 30 for vaporizing the heat transfer oil in a vacuum state by receiving the mixture from the evaporator, a condenser 40 for condensing water vapor evaporated from the evaporator, and condensing and recovering the vaporized heat transfer oil. It is configured to include an oil recoverer (50).

The sludge-oil mixer 10 refers to a device for making a sludge mixture by stirring and mixing the sludge supplied from the sludge storage tank 100 and the heat transfer oil. This refers to a general stirring apparatus, which will be apparent to those skilled in the art, and thus detailed description thereof will be omitted. However, the sludge mixture may be configured to be supplied to the evaporator 20 through the double pipe injector 80 connected as shown in FIG.

The double pipe injector 80 refers to a double pipe which is divided into the inside and the outside of the sludge mixture from the sludge-oil mixer 10 to the evaporator 20, and the oil vapor generated in the vaporizer is the external pipe 81 of the double pipe injector. And heat exchange with the mixture that is passed through the inner tube 82, characterized in that it can be recovered by condensation.

The double tube injector 80 is connected to a device such as a mono pump or a screw conveyor to the inner tube 82 to overcome the pressure difference generated when injecting a mixture mixed at atmospheric pressure into a high-pressure evaporator, and external The tube 81 is connected to the vaporizer 30 in a vacuum state so that oil vapors of about 120 ° C. generated in the vaporizer enter, and condensed into liquid through heat exchange on the surface of the cold inner tube 82 to recover the oil. It is. At this time, the cold sludge mixture passing through the inner tube 82 is configured to enter the evaporator by receiving heat energy as the oil vapor condenses and heat energy, so that the energy can be reused without losing energy in the process of recovering the heat transfer oil. .

The evaporator 20 is a key facility of the present invention for supplying heat energy to the hot plate and transferring it to the sludge mixture to evaporate moisture in the sludge and make it dry.

The evaporator 20 includes a hot plate 21 in a plane, an injection device 22 for injecting the mixture onto the hot plate, and a moving device 23 for moving the mixture on the hot plate. Is sealed and can send all the steam generated in the drying process to the condenser 40, the water vapor is characterized in that it is moved to the condenser through a connecting pipe.

The hot plate 21 is formed of an oil ondol, and the oil ondol includes at least one through hole in a flat and long metal plate, so that the high temperature passes through the through hole so that the heat is transferred. .

In more detail, the oil ondol receives hot oil heated at a suitable temperature from a boiler to transfer thermal energy to the mixture, and the low temperature oil which transfers thermal energy is returned to the oil boiler. Depending on the type of organic sludge, the evaporator efficiency is maximized and the oil temperature is controlled to keep the low temperature oil above 100 ° C.

On the other hand, even if the mixture passed through the evaporator may occur when the water does not evaporate sufficiently may be configured to further include a residual moisture evaporator 90 in the present embodiment. The residual moisture evaporator 90 is separated and configured to differentiate the thermal energy supply to match the evaporation characteristics of the residual moisture that proceeds slowly as drying proceeds due to the evaporation characteristics of the sludge, the oil ondol of the residual moisture evaporator is 100 ℃ or more While maintaining the temperature, the generated water vapor is sent to the condenser, and the dried sludge mixture is sent to the connected oil vaporizer 30, which is also all sealed.

Meanwhile, as another embodiment of the evaporator 20, the following configuration is also possible.

In the present embodiment, the evaporator 20 is formed of a long sealed cylinder, and is composed of a hot plate 21, a wire mesh conveyor 24 and an injection device 22 placed thereon. The evaporator is made of a long cylindrical container to withstand pressure and temperature changes, and the hot plate is accommodated in the cylindrical container. In this case, a hot plate, a wire mesh conveyor, a foam box 28), a cylindrical container, and the like are structurally installed to configure an evaporator so that thermal deformation problems due to temperature and pressure changes do not occur.

The hot plate 21 is configured such that an electric heating wire or a hot oil is directly in contact with the inside of the hot plate to generate strong heat energy in order to deliver strong heat energy to the mixture to explode dry the sludge, and the sludge mixture is directly on the hot plate. Contact to ensure maximum thermal energy transfer.

In addition, the hot plate 21 is preferably configured with a 'c' shaped foam box so that oil bubbles generated during drying of the mixture does not flow out.

As shown in FIG. 3, the wire mesh conveyor 24 is formed of a metal rod 25 having high thermal conductivity at regular intervals to form a wire mesh and connected to the chain 26 so as to be transportable on the hot plate 21. The mixture is injected into the space between the metal rods and the metal rods and transported on the hot plate and dried.

In addition, the evaporator may be configured to further include an injection tube 27 having no bottom plate, and the wire mesh conveyor may be configured to pass through the injection tube and the hot plate. The mixture is injected by gravity through the injection barrel and between the metal rods to the wire mesh conveyor so that the mixture is continuously thinly placed on the hot plate along the wire mesh conveyor passing under the injection cylinder. The heat transfer is thus better done, especially by drying the mixture thinly on a flat wire plate with a flat wire conveyor to completely dry the sludge without overflowing the foam in the foam box.

In other words, as the mixture is dried, the heat transfer oil ratio in the mixture is increased, and the sludge boils in the continuous transfer oil, thereby generating oil bubbles. As the result of the experiment, foaming occurs about 30 times of the mixture, so if the proper capacity box is installed on the hot plate and the mixture is thinned, the oil bubbles do not overflow to the outside and the drying proceeds, and the oil bubbles disappear without drying out.

When the chain 26 of the wire mesh conveyor as described above is operated by a rotating motor, the wire mesh conveyor is brought into close contact with the hot plate 21, and a gull-shaped injector 27 without a bottom is installed in the space where the wire mesh conveyor passes, and the sludge mixture When the mixture is supplied, the mixture is thinly and uniformly injected between the metal bars of the wire mesh conveyor by gravity and the movement of the wire mesh conveyor, and thermal energy is rapidly transferred to the sludge mixture through the hot plate and the metal rod, and sludge drying proceeds. In addition, the mixture is continuously moved over the hot plate by a wire mesh conveyor, so that the sludge mixture is completely dried and drops to the sludge outlet at the end of the hot plate.

The condenser 40 refers to a device for recovering the entire amount of condensed water without flowing out a large amount of water vapor generated in the evaporator or the residual moisture evaporator to the outside. The condenser is possible in two embodiments, low pressure and high pressure.

The low pressure condenser is a heat exchanger that condenses water vapor at 100 ° C at 1 atmosphere and is installed with an external cooling water supply pipe and a condensate discharge pipe, and the condensate discharged to room temperature after heat exchange is separated into heat transfer oil and discharge water through an oil separator. Is connected to a simple purifier, discharged after purification, and separated and recovered heat transfer oil is configured to be sent to the oil tank. The condenser is equipped with a pressure-sensitive steam generator and a hot water heat exchanger to recover the thermal energy of the steam to produce clean steam from the cooling water supplied from the outside.

When the condenser's reduced pressure steam generator enters the inlet of the condenser at 100 ° C., the pressure of the evaporator plate is reduced to 500 mmHg (about 0.66 atm) in the suction blower connected to the reduced pressure steam generator. The cooling water present causes vigorous vaporization at 89 ° C. As a result, the surface temperature of the evaporator plate is maintained at 89 ° C, and water vapor introduced from the evaporator loses heat to become condensed water at 89 ° C, falls to the bottom, enters the heat exchanger through a drain pipe, and exchanges heat with cooling water at room temperature supplied from the outside. After that, it becomes discharged water at room temperature and is discharged to the oil / water separator through the connecting pipe. The supplied clean coolant is heated to 89 ° C through heat exchange with condensate, and is supplied to the evaporation plate of the pressure-sensitive steam generator through a supply pipe to receive thermal energy from steam at 100 ° C. However, the suction blower is reduced to 500mmHg and vaporized at 89 ° C to generate clean steam, and the evaporator plate is equipped with a valve to keep the horizontal level constant so that the amount of cooling water is evaporated, and the generated vapor at 89 ° C. The heat exchange during the steam inflow of 100 ℃ leads to 100 ℃ steam, and clean steam is produced after passing through the blower.

In the high pressure condenser, the sludge mixture is dried at a high temperature and high pressure in a sealed evaporator, and water vapor generated at about 120 ° C. in two atmospheres enters the condenser through a steam outlet and a connection pipe installed at the upper part of the evaporator, and condenses through a steam generator and heat exchange. The condensate is cooled and discharged to room temperature through a tank installed in the condenser and a heat exchanger, and clean water at room temperature is supplied to the heat exchanger and heated to a high temperature. The discharged condensate can be separated by an oil-water separator to recover the heat transfer oil to the oil tank and send the discharged water to the sewage treatment plant.

The vaporizer 30 refers to a device for vaporizing and recovering heat transfer oil from the dried mixture. Heat transfer oil contained in the mixture dried in the evaporator is vaporized by heating from the vaporizer to the hot plate by using the property of a liquid that transfers heat energy rapidly through vaporization and condensation when present in saturated vapor in the vaporizer (30) The oil vapor enters the oil return unit 50 which condenses and recovers the steam through the steam outlet of the carburetor.

At this time, the oil return unit 50 may be a separate configuration, but the outer tube 81 of the double tube injector 80 divided into the inside and outside to transfer the mixture from the sludge-oil mixer 10 to the evaporator 20. The oil vapor generated in the vaporizer 30 may pass through the outer tube 81 of the double tube injector and exchange heat with the mixture that is transferred through the inner tube 82.

That is, the double tube injector 80 is composed of a double tube, the inner tube is an injection tube so that the cold sludge mixture is thinly in contact with the inner tube wall, the heat exchange with the oil vapor outside the inner tube is heated to the evaporator After entering, the oil vapor is condensed while maintaining the equilibrium vapor pressure is collected in the lower tank along the outer tube and is recovered to the oil storage tank 200 by the pressure pump. At this time, the temperature of the other parts of the oil vapor contactor, such as vaporizer or dry sludge container is maintained higher than the vaporization temperature so that the heat transfer oil vaporized in the hot plate of the vaporizer constitutes the oil recovery unit 50 so that all can be condensed only in the double pipe.

On the other hand, when the evaporator or vaporizer uses an oil ondol as a hot plate requires an oil boiler. In this case, the sludge drying apparatus further includes an oil boiler 60 for heating the oil as shown in FIG. 1, wherein the oil heated in the oil boiler is passed through the distributor 61 coupled to the oil boiler. And it is sent to the carburetor 30 and supplied with heat is recovered to the oil boiler, the oil boiler can be configured to heat the heat generated by incineration of the sludge dry matter recovered from the vaporizer.

On the other hand, 80% of the water sludge is very flexible, but when completely dried, the volume decreases and hardens as it is hard to be discharged, so that it can be configured to install the grinder 95 at the outlet of the evaporator.

The grinder 95 is installed in the upper and lower two pairs of grinding rollers and the upper roller is operated in a gear-type meshing groove with each other and the lower roller is installed so that the rotational speed is one fast and one is slow, the upper gear roller In the first grinding and passing between the fine rollers to rotate differently from the lower roller and finely crushed sludge mixture is introduced into the vaporizer through the injection device.

On the other hand, the sludge drying apparatus may be configured to further include a recovery container 70 that can recover the sludge dried in the vaporizer. In this configuration, the recovery container 70 accommodates the dry sludge dropped from the vaporizer 30 by gravity, and when the recovery container is filled with dry sludge, the recovery container 70 locks the valve 71 that can lock the recovery container and then dries it. When sludge is discharged and the container is reconnected, the valve is evacuated and the valve is opened to maintain the vacuum required for oil vaporization in the vaporizer to maintain continuous operation.

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

First, the embodiment of maintaining the pressure of the evaporator and the vaporizer constant to 1 atm atmospheric pressure level is operated as follows.

Organic sludge of about 80% of moisture content, which is brought in from the outside and stored in the storage tank, is introduced into the sludge-oil mixer 10 using a screw conveyor and mixed with the sludge at an appropriate ratio by using light oil or kerosene, which is fuel oil, as a heat transfer oil. It is injected into the evaporator 20.

In the embodiment of maintaining the pressure of the evaporator and the vaporizer at atmospheric pressure, the evaporator 20 is installed on the bottom of the oil ondol of about 200 ℃ acts as a hot plate to perform a rapid heat transfer to the injected mixture to vaporize the water of the sludge rapidly The oil ondol is of a suitable size so that the mixture can pass through the evaporator for about 30 minutes.

In addition, a moving device moving at a constant speed is mounted in the evaporator so that the mixture passing through the evaporator is crushed through the grinder 95. This is because the final drying of the sludge is slow, and the shape of the sludge dry matter is finely changed by the pulverizer to change the shape to promote evaporation.

After that, if residual moisture is present, it may be added to the residual moisture evaporator 90 to evaporate the residual moisture once again. When the dried and pulverized sludge mixture is dropped on the upper surface of the residual water evaporator with the oil ondol of about 150 ° C., the evaporation proceeds slowly, and the mixture is lowered to the lower side of the evaporator. 30).

The vaporizer 30 is installed with an oil ondol of 350 ℃ to quickly vaporize the heat transfer oil of the dried mixture to make a dry sludge. The generated oil vapor is passed to the sludge-oil mixer 10 after passing through the oil recovery unit 50.

The dried sludge has more than 3500 Kcal of heat per kg, and when used as fuel for incinerators, it provides enough heat energy for sludge drying with 80% water content as the heat of sludge itself, even if the thermal efficiency of the entire apparatus is maintained at about 75%.

To this end, the heat of the combustion gas is recovered to increase the thermal efficiency of the incinerator, and when the supply air is heated to 350 ° C or higher to burn high temperature dry sludge, a combustion chamber outlet temperature of 850 ° C or higher is maintained to maintain an appropriate incineration temperature. The oil is heated to 350 ° C. in the oil boiler and sent to the oil distributor, which supplies thermal energy to each oil ondol.

At this time, the heating oil of 350 ° C. can be directly contacted with the vaporizer 30, and 200 ° C. is supplied to the evaporator and 150 ° C. with the residual water evaporator. Supply the oil at the correct temperature. Cold oil, which has lost its thermal energy recovered after use, is sent to the boiler for reheating.

A large amount of water vapor generated in the evaporator is discharged to the water vapor outlet located in the upper part of the evaporator to produce clean steam by using the cooling water through a heat exchanger connected to the pressure-sensitive steam generator in the condenser 40 connected to the steam vapor of the evaporator is recovered and recovered as the total condensate The condensate is separated into a heat transfer oil and an effluent in an oil separator, and the heat transfer oil is sent to an oil tank for reuse in a sludge-oil mixture, and the effluent is discharged after the water purification treatment in a simple clarifier so that no odor occurs outside.

On the other hand, the embodiment of maintaining the temperature of the evaporator and vaporizer constant to 120 ℃ level is operated as follows. A mixture of sewage sludge and heat transfer oil (petroleum with a vaporization point of about 200 ° C.) is mixed at an appropriate rate and fed into the evaporator through an injector through a feeder mounted down by gravity. The injector 80 passes through a double tube and the mixture is heated to near 100 ° C. and enters the evaporator through a connected inlet tube.

In the evaporator, a wire mesh conveyor 24 and a hot plate 21 are placed in a foam box 28. A thin bottom spaced injection tube 27 is installed on the hot plate, and the metal rod of the wire mesh conveyor 25 is installed between the hot plate and the injection tube. ) Is configured to pass. The sludge mixture introduced into the injection barrel is injected into the wire mesh conveyor, and when the connected chain is operated by the rotary motor, the mixture is rapidly dried by being supplied with thermal energy as the mixture passes over the hot plate with a thickness as thin as a gap between the hot plate and the injection cylinder.

The mixture is thin and uniformly injected between the metal rods of the wire mesh conveyor by gravity and the movement of the wire mesh conveyor so that heat energy is quickly transferred to the sludge mixture through the hot plate and the metal rod, and sludge drying proceeds, and the wire plate conveyor moves on the hot plate. As a result of the continuous drying, the sludge mixture dries to the sludge outlet at the end of the hot plate where the moisture is completely dried.

The steam at 120 ° C and 2 atmospheres generated by the sludge drying enters the condenser 40 through a steam outlet and a connection pipe installed at the upper part of the evaporator, and condenses through heat exchange with the steam generator. Cooled to room temperature and discharged to the pump, instead, clean water at room temperature is supplied to this heat exchanger, heated to high temperature, produced as clean steam from the steam generator, and discharged to the steam outlet. The discharged condensate is separated by an oil / water separator to heat transfer oil. Is recovered to the oil tank 200 and the discharged water is sent to a sewage treatment plant.

The sludge mixture dried in the evaporator is passed through the grinder 95, and passes between the rapidly rotating fine rollers to be finely ground. The ground sludge mixture is introduced into the vaporizer 30 through an injection device.

The dry sludge mixture put into the vaporizer is supplied with thermal energy through a thin plate by an injection device having a structure such as an evaporator and a hot plate and a wire mesh conveyor, and the heat transfer oil is vaporized in a vaporized state in the vaporized vaporizer 30 so that the oil is saturated. Drained into the steam conduit, the dry sludge passes through the valve 71 by gravity and into the dry sludge vessel 70.

When the dry sludge is filled in the container 70, the valve 71 connected to the carburetor is locked, and the discharge port of the container is opened to discharge dry sludge.When the discharge is completed, the discharge port is closed again, the container is evacuated, and the valve 71 is opened to dry. The sludge is discharged and the dry sludge is discharged while maintaining the inside of the vaporizer in a saturated steam of heat transfer oil so that the vaporizer can be operated continuously.

The above operation described only the embodiment of keeping the pressure of the evaporator and the vaporizer constant and the embodiment of keeping the temperature constant, but the embodiment of changing the temperature and pressure in accordance with the applied vapor pressure can be any number, the present invention Make sure that you fall within the scope of your rights.

As described above, in the present invention, the sludge drying method using heat transfer oil can be put to practical use, and then the sludge is dried by using an evaporator and a vaporizer equipped with a hot plate and a wire mesh conveyor, and the sludge is dried. The present invention provides a sewage sludge drying apparatus configured to recover heat transfer oil, which is used as a catalyst for sludge drying, by using a liquid that transfers heat energy rapidly through vaporization and condensation when present in saturated steam alone. The device has the advantage of being simple to install.

The present invention as described above is not limited to the present embodiment, and the modifications can be made as many as possible without departing from the spirit of the present invention.

The present invention is difficult to process by the technology to date through the above-described technical configuration and operation, the organic sludge that is dumped off the sea as a waste by mixing the heat transfer oil by water and oil step by step through the drying device separated by evaporator, vaporizer By separating the sludge completely and making it possible to utilize it as renewable energy, sewage sludge is economically and cleanly dried incinerated to replace ocean dumping to provide environmentally friendly technology to avoid international criticism and prevent marine pollution.

In addition, in the present invention, all evaporators are made in a closed structure so that drying is performed without generating dust and odor at all. In addition, the odorous water vapor in the drying process is recovered by condensed water in all the amount is discharged after purification treatment. Therefore, the method and apparatus of the present invention are easy to install in a sewage treatment plant or a livestock complex where organic sludge is generated, thereby reducing the transport cost for sludge disposal and reducing the air pollutants generated in a large vehicle, thereby helping to protect the environment. .

In addition, the present invention significantly improves the thermal efficiency of the sludge drying apparatus to develop a method that can completely dry the sludge by utilizing the heat amount of the organic sludge, and the steam generated during the sludge drying process is reproduced as clean steam through the connected condenser It is used as renewable energy.

When calculating this, 200Kg of dry sludge is recovered per tonne of sludge with 80% water content, and this dry sludge possesses about 3500Kcal of heat per 1Kg, which can recover 700,000 Kcal of renewable energy per ton of sludge. In other words, it is expected to secure 70 million liters of oil replacement effect if 70 million tons of organic sludge is treated by securing renewable energy to replace 70 liters of oil.

In addition, the present invention provides a drying process that can continuously proceed the drying and incineration process of the organic sludge by automating the entire process, in particular the new heat transfer oil technology significantly improves the drying efficiency and does not require a high cost deodorization equipment drying device By reducing the size and parts of the system to a larger size than the existing facilities, it is possible to provide a high-efficiency device with low facilities and operating costs.

Claims (16)

A mixing step of generating a mixture by mixing the heat transfer oil having a boiling point higher than that of water and having a low vapor pressure with the sludge, A drying step of heating the mixture to remove the moisture of the mixture by using the heat transfer oil as a heat transfer catalyst, and drying the mixture; And a recovery step of heating the mixture to vaporize the heat transfer oil to condense and recover the heat transfer oil. Characterized in that the sludge is dried using the difference between the vapor pressure of water and oil, Sludge drying method using heat transfer oil. The method according to claim 1, The process of evaporation of oil and moisture of the mixture, It is separated into the drying step of evaporating water and the recovery step of evaporating oil, To keep the temperature and pressure different in each sealed container, After extracting the water in the drying step preferentially, the oil is extracted in the recovery step, Sludge drying method using heat transfer oil. The method according to claim 2, In the evaporation process of the water and oil, the sealed container is filled with only water vapor and oil vapor, characterized in that Sludge drying method using heat transfer oil. The method according to claim 1 or 2, The drying step of the mixture is characterized in that the heating on a flat hot plate so that the oil does not collect, Sludge drying process using heat transfer oil. The method according to claim 1 or 2, Further comprising a steam condensation step of producing a clean steam by condensing the steam generated in the drying step, Sludge drying method using heat transfer oil. The method according to claim 1, The mixture is characterized in that the mixing ratio of the sludge and the continuous delivery oil is 1: 0.5 ~ 1: 0.8, Sludge drying method using heat transfer oil. The method according to claim 1, The heat transfer oil is characterized in that the vapor pressure is a liquid of 1/10 level than the vapor pressure of water, Sludge drying method using heat transfer oil. The method according to claim 7, The heat transfer oil is characterized in that the vaporization point is about 200 ℃ petroleum, Sludge drying method using heat transfer oil. In the sludge drying apparatus used in the sludge drying method of claim 1, A sludge-oil mixer which mixes sludge and heat transfer oil to produce a mixture, An evaporator for receiving and drying the mixture from the sludge-oil mixer; A vaporizer for receiving the mixture from the evaporator and vaporizing the heat transfer oil in a vacuum state; A condenser for condensing water vapor evaporated from the evaporator, Containing an oil recovery unit for condensing and recovering the vaporized heat transfer oil, Sludge drying device using heat transfer oil. The method according to claim 9, The evaporator, The hot plate of the plane, An injection device for injecting the mixture onto the hot plate; A moving device for moving the mixture on the hot plate, The evaporator is characterized in that the sealed, Sludge drying device using heat transfer oil. The method according to claim 10, The hot plate is formed of oil ondol, The oil ondol includes at least one through hole in the flat metal plate, so that the high temperature through the through hole to allow the heat to pass through the oil, Sludge drying device using heat transfer oil. The method according to claim 10, The mobile device, Characterized in that the conveying the mixture on the hot plate, the metal rods having a high thermal conductivity are arranged at regular intervals to form a wire mesh to be connected to the chain to be transportable, Sludge drying device using heat transfer oil. The method according to claim 10 or 12, The evaporator further comprises an injection tube without a bottom plate, The wire mesh conveyor passes between the injection barrel and the hot plate so that the mixture is injected between the metal rods to the wire mesh conveyor through the injection barrel, so that the mixture is continuously thinly placed on the hot plate. Sludge drying device using heat transfer oil. The method according to claim 9, The sludge drying apparatus further includes an oil boiler for heating oil, The oil heated in the oil boiler is sent to the evaporator and the carburetor through a distributor coupled to the oil boiler, after supplying heat to the evaporator and carburetor, is recovered to the oil boiler, Sludge drying device using heat transfer oil. The method according to claim 9, The sludge drying apparatus further includes a recovery container for recovering the dried sludge, The recovery container accommodates the dry sludge dropped by gravity from the vaporizer, When the recovery container is filled with dry sludge, the valve connected to the carburetor is closed and the sludge is discharged and vacuumed, and then the valve is opened to maintain the vacuum state of the vaporizer and discharge the dry sludge. Sludge drying device using heat transfer oil. The method according to claim 9 to 12, The sludge drying apparatus further includes a double tube injector divided into an inside and an outside of the sludge-oil mixer to transfer the mixture from the sludge-oil mixer to the evaporator. The oil vapor generated in the vaporizer passes through the outer tube of the double tube injector and can be condensed and recovered by heat exchange with the mixture transferred through the inner tube. Sludge drying device using heat transfer oil.

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