SLUDGE TREATMENT SYSTEM AND CARBURETER
Background of Invention Technical Field The present invention relates to a sludge treatment system, and more particularly, to a sludge treatment system which applies, in a vaporizing chamber, heat and various waves such as very high frequencies, very low frequencies, magnetic waves, electronic waves, ultrasonic waves, and the like, to slurry not dewatered in a settling tank, to decrease an intermolecular binding force between the sludge and water and generate combustible gas, thereby using the generated combustible gas in an incinerator as fuel for incinerating the sludge deprived of the combustible gas.
Background Art In a conventional wastewater treatment procedure, wastewater is treated in such a way as to be biologically decomposed while passing through a bioreactor including an anaerobic tank and an aerobic tank, etc. Then, the treated wastewater is supplied to a settling tank and divided into liquid and solid. Next, after high- performance liquid is recovered, a part of settled sludge is re-supplied into the bioreactor to maintain a proper concentration of microorganism in the bioreactor, and remnant sludge is thickened in a sludge thickener. Thereupon, after chemicals are added to the sludge in a chemical mixer, the sludge is dewatered in a dewatering tank.
A cake formed after dewatering is reclaimed or incinerated. However, in the conventional wastewater treatment procedure, secondary
water pollution is likely to occur in the course of separating the sludge or depending upon an amount of chemicals when adding chemicals in the chemical mixer. Further, the water dewatered in the dewatering process can cause the secondary water pollution. Meanwhile, in the case that the sludge produced in the wastewater treatment procedure is reclaimed or dumped into the sea, since serious soil pollution or water pollution is caused, regulations have been established to limit reclamation or ocean- dumping of sludge. For this reason, these days, an incineration method is being mainly used. Nevertheless, the incinerating method suffers from defects in that, since a substantial amount of water is contained in the sludge, a great deal of energy, that is, fuel (fossil fuel) is required to remove the water from the sludge, rendering economic efficiency poor.
Disclosure of the Invention Therefore, the present invention has been made in view of the above- mentioned problems, and an object of the present invention is to provide a sludge treatment system which applies, in a vaporizing chamber, heat and various waves to slurry settled in and separated from a settling tank, to decrease an intermolecular binding force between the sludge and water and generate combustible gas, so that the generated combustible gas can be used in an incinerator for incinerating the sludge deprived of the combustible gas and a dewatering process can be omitted due to incineration of the sludge after generation of combustible gas, thereby minimizing a sludge incineration cost and water pollution. In order to achieve the above object, according to the present invention, there is provided a sludge treatment system comprising the processes of: separating
sludge settled in a settling tank, after wastewater is treated in such a way as to be biologically decomposed while passing through a bioreactor including an anaerobic tank and an aerobic tank, and the treated wastewater is supplied .to the settling tank to be divided into liquid and solid; applying, in a vaporizer, heat and various waves including very high frequencies, very low frequencies, magnetic waves, electronic waves and ultrasonic waves to the separated slurry, to decrease an intermolecular binding force between the sludge and water and generate combustible gas; and feeding the resultant sludge deprived of the combustible gas into an incinerator, and incinerating the resultant sludge using combustible gas generated in the vaporizer as fuel.
Brief Description of Drawings Further objects and advantages of the invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings in which: FIG. 1 is a block diagram illustrating process flow in a sludge treatment system in accordance with an embodiment of the present invention; and FIG. 2 is a partial enlarged cross-sectional view illustrating the sludge treatment system according to the present invention.
Best Mode for Carrying Out the Invention Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.
Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.
FIG. 1 is a block diagram illustrating process flow in a sludge treatment system in accordance with an embodiment of the present invention, and FIG 2 is a partial enlarged cross-sectional view illustrating the sludge treatment system according to the present invention. As can be readily seen from the drawings, in a sludge treatment system in accordance with an embodiment of the present invention, a sludge separating process is implemented in a manner such that sludge settled in a settling tank 10 is separated, after wastewater is treated in such a way as to be biologically decomposed while passing through a bioreactor including an anaerobic tank 1 and an aerobic tank 2, and the treated wastewater is supplied to the settling tank 10 to be divided into liquid and solid. In the sludge separating process, since the sludge settled in the settling tank 10 is separated along with water, a great amount of water is contained in the sludge. However, in the present invention, because a dewatering process for separating only the sludge is not implemented, secondary water pollution is avoided, which is otherwise caused in the conventional art due to dewatering of the sludge. The sludge separated as described above is vaporized in a vaporizer 20. The vaporizer 20 comprises a cylinder 21. A feeding screw 22 is disposed in the cylinder 21. The cylinder 21 has an inlet opening 23 a which is defined through an upper wall at one end of the cylinder 21, an outlet opening 23b which is defined through a lower wall at the other end of the cylinder 21, and a gas discharge opening
24 which is defined through the upper wall at a middle portion of the cylinder 21.
Wave generating devices 25 through 29 for generating very high frequencies, very low frequencies, magnetic waves, electronic waves and ultrasonic waves are installed on the wall of the cylinder 21. At this time, the magnetic wave generating device
27 comprises coils 271 wound on an outer surface of the cylinder 21, and permanent magnets 272 secured to the feeding screw 22. A duct 32 is placed around the cylinder 21 to apply heat of a high temperature to the cylinder 21. If the sludge is inputted through the inlet opening 23a of the vaporizer 20, the sludge is moved by the feeding screw 22 toward the other end of the cylinder 21 and then discharged through the outlet opening 23b. While the sludge passes through the vaporizer 20, as very high frequencies, very low frequencies, magnetic waves, electronic waves and ultrasonic waves generated from the wave generating devices 25 through 29 are applied to the sludge, an intermolecular binding force between the sludge and water is decreased. At this time, the magnetic wave generating device 27 is operated in a manner such that the permanent magnets 272 cooperate with the coils 271 wound on the cylinder 21 while the feeding screw 22 is rotated, to generate magnetic waves. As the heat of a high temperature is applied to the cylinder 21 and conducted through the wall of the cylinder 21, the water and sludge are heated to generate vapors. That is to say, since heat is applied in a state wherein an intermolecular binding force between the sludge and water is decreased, it is possible to accomplish high vaporization efficiency with a low calorie. The vapors generated through this action comprise hydrogen and oxygen analyzed from water and combustible gases such as ammonia and so forth analyzed from the sludge. The separated combustible gases are discharged and collected through the gas discharge port 24 which is defined through the upper wall at the middle portion of the cylinder 21. The sludge containing water not vaporized in the vaporizer 20 is discharged through the outlet port 23b and fed into an incinerator 30, and the combustible gases
collected in the vaporizer 20 is also supplied into the incinerator 30 to be used as fuel for incinerating sludge. The combustible gases collected and supplied into the incinerator 30 have a calorific value which is sufficient to incinerate the sludge without additional supply of fuel. Also, the heat remaining after incinerating the sludge in the incinerator 30 is supplied into the vaporizer 20 to be used in vaporizing the water and sludge.
Industrial Applicability As apparent from the above descriptions, the sludge incineration system according to the present invention provides advantages in that heat and various waves such as very high frequencies, very low frequencies, magnetic waves, electronic waves, ultrasonic waves, and the like, are applied in a vaporizing chamber to the slurry settled in and separated from a settling tank, to decrease an intermolecular binding force between the sludge and water and generate combustible gas, so that the generated combustible gas can be used in an incinerator as fuel for incinerating the sludge not vaporized in the vaporizing chamber, thereby ensuring that sludge is incinerated by burning combustible gas generated in the sludge itself without using separate fuel. As a consequence, it is possible to minimize a cost required for incinerating sludge. Further, because the generated combustible gas to be used for incinerating sludge has a high calorific value, it is possible to suppress the generation of a noxious substance such as dioxin while incinerating sludge. Also, due to the fact that the sludge is separated from the settling tank without separately performing a dewatering process, it is possible to prevent water pollution which is otherwise caused in the course of dewatering sludge in the conventional art.
Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.