Title of Invention	CEMENT BURNING APPARATUS AND METHOD OF DRYING HIGH-WATER-CONTENT ORGANIC WASTE
Abstract	ABSTRACT [Abstract! [Prohlems] To provide a cement burning apparatus and a method of drying higlrwater-content organic waste capable of reducing a danger of explosion at a facility for dryingi avoiding decreased value of dried sludge as a fuel- and more efficiently drying high-water-content organic waste. [Means for Solving Problems] The cement burning apparatus 1 comprises a dryer 6 for drying high-water content organic waste of which water content is 40 mass percent or more, in which combustion gas extracted from outlet portions or ceiling portions of preheater cyclones 3A to 3D of a cement kiln 2 is fed to the dryer 6. As the dryer 6, a grinding-type flash dryer, which directly contacts the comhustion gas G with the high-water-content organic waste W while grinding it, can be used. In addition, the apparatus 1 further comprises a coarse powder separator ]2 for separating coarse powder from the combustion gas extracted from the range described above, and the combustion gas G from which dust is separated by the coarse powder separator 12 can be fed to the dryer 6, and the dust concentration of the gas fed to the dryer 6 may be adjusted to 0.05kg?Nma or more and 0.35kg/Nma or less. [Selected Drawing! Figure 1

Title of Invention

CEMENT BURNING APPARATUS AND METHOD OF DRYING HIGH-WATER-CONTENT ORGANIC WASTE

Abstract

ABSTRACT [Abstract! [Prohlems] To provide a cement burning apparatus and a method of drying higlrwater-content organic waste capable of reducing a danger of explosion at a facility for dryingi avoiding decreased value of dried sludge as a fuel- and more efficiently drying high-water-content organic waste. [Means for Solving Problems] The cement burning apparatus 1 comprises a dryer 6 for drying high-water content organic waste of which water content is 40 mass percent or more, in which combustion gas extracted from outlet portions or ceiling portions of preheater cyclones 3A to 3D of a cement kiln 2 is fed to the dryer 6. As the dryer 6, a grinding-type flash dryer, which directly contacts the comhustion gas G with the high-water-content organic waste W while grinding it, can be used. In addition, the apparatus 1 further comprises a coarse powder separator ]2 for separating coarse powder from the combustion gas extracted from the range described above, and the combustion gas G from which dust is separated by the coarse powder separator 12 can be fed to the dryer 6, and the dust concentration of the gas fed to the dryer 6 may be adjusted to 0.05kg?Nma or more and 0.35kg/Nma or less. [Selected Drawing! Figure 1

Full Text	SPECIFICATION CEMENT BURNING APPARATUS AND METHOD OF DRYING HTGH-WATER-CONTENT ORGANIC WASTE TECHNICAL FIELD [OOOl] The present invention relates to a cement burning apparatus capable of safely and efficiently drying high-water-content organic waste such as high-water-content organic sludge and a method of drying high-watercontent organic waste utilizing the apparatus. BACKGROUND ART [0002] Conventionally, variety of apparatus and methods for treating waste such as city garbage in cement burning apparatus has been proposed. For instance, in the patent document 1 is disclosed a technology, in which a part of hot air from a clinker cooler is introduced to a dryer for drying waste such as city garbage; gas exhausted from the dryer is returned to the clinker cooler! and the hot air, with which the exhaust gas is mixed, from the clinker cooler is used as air for combustion in a cement kiln or a calciner. [0003] Further, in the patent document 2, a technology for burning combustible waste in cement burning apparatus is disclosed. In this technology, combustible waste is burned with a part of hot air from a clinker cooler! exhaust gas generated in a waste burning process is aerated to a preheater for heating cement raw material! and slug generated in the waste burning process is extracted. [0004) However, as described in the above patent documents, the hot air extracted from the clinker cooier can be utilized for drying waste such as city garbage, combustible waste and the like without causing any trouble, but when the hot air is utilized for drying high-watei-content organic waste such as high-water-content-organic sludge, oxygen concentration of the hot air is high so that there is a danger of explosion. [0005] In addition, even if combustion exhaust gas downstream from the exit of a preheater of a cement burning apparatus was tried to be utilized, since temperature of the combustion exhaust gas in the range was low, that is, 450CC or less, the gas would not be suitable to dry the high-water-content, sludge. On the other hand, gas extracted from the inlet end of a cement kiln is low in oxygen concentration and high in temperature, that is, approximately 1000 "C, so that it is suitable to dry the high-water content organic waste, but extraction of the combustion gas from the inlet end causes a problem that thermal efficiency of the cement kiln decreases. [OOOfi] In consideration of the above problems, the present applicant has eagerly investigated and found that oxygen concentration of the combustion gas extracted from the exhaust gas passage, which runs from the outlet duct of the calciner to the outlet duct of the preheater of the cement kiln is low, that is, 2 to 8 percent, so that there is no danger of explosion, and since temperature of the combustion gas is 450 to 900°C, the high-water-content organic waste can sufficiently be dried and combustion gas is not extracted from the inlet end or the like of the cement kiln, which does not decrease thermal efficiency of the cement kiln. [0007] Patent document l: Japanese Patent Publication Showa 63-151650 gazette Patent document 2- Japanese Patent Publication 2003-506299 gazette DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION [0008] As described above, in order to dry high-water-content sludge etc., the combustion gas extracted from the exhaust gas passage, which runs from the outlet duct of the calciner to the outlet duct of the preheater of the cement kiln, can be used. Rut, the gas exhausted from the cement kiln as a hot source gas for drying contains incombustible dust derived from cement raw material, and most of the dust is recovered in dried sludge. In addition, dust concentration of the cement kiln exhaust gas is between approximately 0.05kg/Nm:1 (at an outlet portion of the highest cyclone) find approximately 1.0 kg/Nm3 (at an inlet portion of each cyclone), which means that the concentration considerably varies with area from which the combustion gas is extracted. [00091 Here, the dried sludge containing dust, derived from cement raw material has advantages and disadvantages. An advantage is that the dried sludge containing incombustible dust reduces danger of explosion at a facility for drying. On the contrary, a disadvantage is that the dried sludge containing incombustible dust reduces value of the dried sludge as a fuel, [0010] In addition to the above, the high-water content organic sludge shapes clumps including 40 mass percent of water or more like clay and its specific surface area is small, which makes it difficult to efficiently dry the organic sludge. [0011] The present invention has been made in consideration of the above problems in the conventional art, and the object thereof is to provide a cement burning apparatus and a method of drying higlvwatercontent organic waste reducing the danger of explosion at the facility for drying; not causing decreased value of the dried sludge as a fuel! and efficiently drying high-water-content organic waste. MEANS FOR SOLVING PROBLEMS [0012] To achieve the above object, the present invention relates to a cement burning apparatus, and the apparatus is characterized by comprising: a dryer for drying high-watercontent organic waste of which water content is 40 mass percent or more, wherein combustion gas extracted from one of an exhaust gas passage from a gas outlet to a portion immediately before a material feed portion and a ceiling portion of a preheater cyclone of a cement kiln other than a highest cyclone is fed to the dryer. [0013] In this invention, from one of an exhaust gas passage from a gas outlet to the portion immediately before a material feed portion and a ceiling portion of a preheater cyclone of a cement kiln other than a highest cyclone is extracted a part of combustion gas with low dust concentration, and in a dryer is dried high-watei-content organic waste of which water content is 40 mass percent or more by using the part of combustion gas of low dust content, so that dust content of the organic waste after dried also becomes low, which prevents decreased value of the dried organic waste as a fuel. [0014] The above cement burning apparatus may further comprise a coarse powder separator for separating coarse powder from the combustion gas extracted from one of the exhaust gas passage from the gas outlet to the portion immediately before the material feed portion and the ceiling portion, wherein combustion gas from which the coarse powder is separated by the coarse powder separator is fed to the dryer. With this construction, dust content of the organic waster after dried can be lower, which further increases the value of the dried organic waste as a fuel. [0015] In the above cement burning apparatus, the dryer can be a grinding-type flash dryer, to which the combustion gas is fed so as to directly be contacted with the high-water-content organic waste, for drying the organic waste while grinding it. With this, improved drying efficiency through increased specific surface area of the high-water-content organic waste and improved grinding efficiency through superficial drying of the high-water-content organic waste can between them exponentially improve overall drying efficiency. [0016] In the above cement burning apparatus, dust concentration of the gas that is fed to the dryer can be 0.05kg/Nma or more and 0.35kg/Nm3 or less. With this, it becomes possible to reduce the danger of explosion at a facility for drying while preventing decreased value of dried sludge as a fuel. [0017] In the above cement burning apparatus, the high-watercontent organic waste may be high-water con tent organic sludge, and paper sludge, sewerage sludge, building pit sewerage sludge, food sludge and so on may be dried. [0018] Further, the present invention relates to a method of drying high-watercontent organic waste, and the method is characterized by comprising the steps of; extracting a part of combustion gas of which dust concentration is in a predetermined range from an exhaust gas passage, which runs from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln; and drying high-water-content organic waste of which water content is 40 mass percent or more by using the part of extracted combustion gas, [0019] With this invention, since high-watercontent organic waste is dried with a combustion gas of which dust concentration is in a predetermined range, it becomes possible to adjust dust concentration of the dried organic waste. [0020] Further, the present invention relates to a method of drying high "water-content organic waste, and the method is characterized by comprising the steps of extracting a part of combustion gas from an exhaust gas passage, which runs from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln; and adjusting concentration of dust contained in the extracted combustion gas to a predetermined range; and drying high-watercontent organic waste of which water content is 40 mass percent or more by using the gas of which dust concentration is adjusted to the predetermined range. [0021] With this invention, since high-watercontent organic waste is dried with a comhustion gas of which dust concentration is in a predetermined range, it becomes possible to adjust dust concentration of the dried organic waste. [0022] In the above method of drying high-watercontent organic waste, the part of the combustion gas may directly be contacted with the higlrwatercontent organic waste, and the organic waste can be dried while being ground. With this, as described above, overall drying efficiency can exponentially be improved. [0023] \n the above method of drying high-water-eontent organic waste, dust concentration of the gas used for drying the high-water-content organic waste can be 0.05kg/Nm3 or more and 0.35kg/Nm3 or less. With this, as described above, it becomes possible to reduce the danger of explosion at a facility for drying while preventing decreased value of dried sludge as a fuel. [0024] In the ahove method of drying high-water-content organic waste, the high"water-content organic waste may be high-water-content organic sludge such as paper sludge, sewerage sludge, building pit sewerage sludge and food sludge. EFFECT OF THE INVENTION [0025] As described above, with the present invention, it is possible to provided a cement burning apparatus and a method of drying high-watercontent organic waste reducing the danger of explosion at the facility for drying; not causing decreased value of the dried sludge as a fuel; and efficiently drying high-watercontent organic waste. THE BEST MODE TO CARRY OUT THE INVENTION [0026] Figure 1 shows a cement burning apparatus according to the first embodiment of the present invention, this cement burning apparatus 1 comprises a cement kiln 2, a preheater 3, a calciner 4, a dryer 6, a fan 7 and others. [0027] The cement kiln 2, the preheater 3 and the calciner 4 have the same construction as conventional cement burning apparatus, and cement raw material R fed to the preheater 3 is preheated in the preheater 3; calcined in the calciner 4; and burned in the cement kiln 2. [0028] To the dryer 6 is fed high"water-content organic waste (hereinafter referred to as "waste") W such as high-water-content organic sludge, and to the dryer 6 is fed combustion gas extracted from an outlet portion of the lowest cyclone 3A to dry the waste W. The combustion gas is extracted from a duet from the outlet portion of the lowest cyclone 3A to an inlet, portion of the second cyclone 3B and in the stage before cement raw material fed from the third cyclone 3C is mixed with the combustion gas, so that the combustion gas is low in dust content, that is, approximately 0.15 to 0.351tg/cm3. As a result, when the gas is used for drying the waste W in the dryer 6, dust concentration of the waste W becomes proper, which makes it possible to maintain the dust content of the waste W low while preventing explosion in the dryer 6. [0029] The fan 7 is installed to introduce combustion gas from the preheater 3 to the dryer 6, and exhaust gas from the fan 7 is returned to the exhaust gas passage, which runs from the lowest cyclone 3A to the second cyclone 3B via a circulation duct 8. [0030l Meanwhile, although in the embodiment described above, to the dryer 6 is fed the combustion gas extracted from the outlet portion of the lowest cyclone 3A, not only from the outlet portion of the lowest cyclone 3A, hut combustion gas extracted from a portion selected from a ceiling portion of the lowest cyclone 3A, outlet portions and ceiling portions of the second cyclone 3B, the third cyclone 3C and the forth cyclone 3D can be fed to the dryer 6 to use the combustion gas for drying the waste W, resulting in the same effect as described above. [0031] Next, a cement burning apparatus according to the second embodiment of the present invention will be explained with reference to Fig. 2. This cement burning apparatus 11 is characterized by comprising, in addition to the construction of the cement burning apparatus 1 shown in Fig. 1, a cyclone 12 aa a coarse powder separator upstream from the dryer 6. Below, to the same composing element as the cement burning apparatus 1 is added the same reference number and the detailed explanation thereof will he omitted. [0032] To the cyclone 12 is fed combustion gas extracted from the outlet portion of the lowest cyclone 3A, and coarse power D in the gas is removed. The removed coarse powder D may be returned to the cement burning apparatus 1 and can be treated out of the cement burning apparatus 1. Combustion gas G containing fine powder, which is not recovered by the cyclone 12, is fed to the dryer 6. [0033] To the dryer 6 is fed the waste W as well as the combustion gas G from the cyclone 12 to dry the waste W. Dust contained in this combustion gas G is collected by the cyclone 12, so that dust content of the gas is low, that is 0.05 to 0.2kg/Nni3, when used for drying the waste W, it becomes possible to maintain the dust content of the waste W low while preventing explosion in the dryer 6. [0034] Meanwhile, although in the embodiment described above, to the cyclone 12 is fed the combustion gas extracted from the outlet portion of the lowest cyclone 3A, not only from the outlet portion of the lowest cyclone 3A, hut combustion gas extracted from a portion selected from a ceiling portion of the lowest cyclone 3A, outlet portions and ceiling portions of the second cyclone 3B, the third cyclone 3C and the forth cyclone 3D can he fed to the cyclone 12 to use the combustion gas G without coarse powder for drying the waste in the dryer 6, resulting in the same effect as described above. [0035] Next, a cement burning apparatus according to the third embodiment of the present invention will be explained with reference to Fig. 3. This cement burning apparatus 21 is characterized in that the cyclone 12 and the dryer 6 of the cement burning apparatus 11 shown in Fig. 2 are exemplified as a cement-raw-material recovery cyclone 22 and a grinding-type flash dryer 23 respectively and is characterized by further comprising a high-water-content organic waste storage tank (hereinafter referred to as "waste storage tank") 24 and dried organic waste recovery cyclone (hereinafter referred to as "dried material recovery cyclone") 27 and so on. Below, to the same composing element as the cement burning apparatus 11 is added the same reference number, and the detailed explanation thereof will be omitted. [0036] The cement-raw-material recovery cyclone 22 is installed upstream, from the grinding-type flash dryer 23 to remove dust included in combustion gas G extracted from the exhaust gas passage of the preheater 3 and to feed the combustion gas G of which dust is removed to the grinding-type flash dryer 23. [0037] The grinding-type flash dryer 23 is installed to dry the waste W fed from the waste storage tank 24 with the combustion gas G fed from the cemenfrawmaterial recovery cyclone 22 while grinding the waste W. This grinding'type flash dryer 23 is provided with a feed opening for the waste W in the upper portion thereof and a feed opening for the combustion gas G from the cement-raw-material recovery cyclone 22 in the lower portion thereof, and the waste W and the combustion gas G are counter-currently contacted with each other. Further, in the grinding-type flash dryer 23 are installed a rotation shaft 23a and strike chains 23b, which are fixed to the rotation shaft 23a and horizontally extend and rotate through centrifugal force together with the rotation of the rotation shaft 23a to grind the waste W. [0038] The waste storage tank 24 is installed to temporarily store high-water-content organic waste and the high-watercontent organic waste can be high-watercontent organic sludge such as paper sludge, sewerage sludge, building pit sewerage sludge and food sludge. [0039] A blower 25 is installed to transport the waste W ground and dried by the grinding-type flash dryer 23 to the preheater 3, and a roots blower or the like may be utilized. A fan 28 is installed to return dry exhaust gas G' discharged from the grinding-type flash dryer 23 via a circulation duct 26 to the preheater 3. [0040] Next, the motion of the cement burning apparatus 21 with the above construction will be explained with reference to figures. [0041] Cement raw material R is fed to the preheater 3 of the cement hurning apparatus 21, and the raw materia] K. is preheated in the preheater 3; calcined in the calciner 14; and burned in the cement kiln 2. On the other hand, received waste W is temporarily stored in the waste storage tank 24. [0042] The fan 28 is operated to introd uce the combustion gas G of the cement kiln 2 to the cement-raw-material recovery cyclone 22, and dust included in the combustion gas G is recovered. The recovered dust is returned to the preheater 3, and the combustion gas G from which the dust is recovered is fed to the grinding-type flash dryer 23. [0043] The waste W from the waste storage tank 24 is fed to the upper portion of the grinding-type flash dryer 23, and the combustion gas G from the cement-raw-materiai recovery cyclone 22 is introduced to the lower portion of the grinding-type flash dryer 23. Since temperature of this combustion gas G is approximately 800 to 9001, high-water-content organic waste can sufficiently be dried. In addition, in the grinding-type flash dryer 23, the waste W and the combustion gas G are directly and counter-currently contacted with each other, and the waste W is dried while being ground by strike chains 23b arranged in the grinding-type flash dryer 23, the waste W is dried from its surface with specific surface area thereof increasing. As a result, in addition to improved drying efficiency due to the increase of the specific surface area, grinding efficiency is also improved due to the dried surface of the waste W, resulting in exponential improvement in overall drying efficiency in comparison to conventional devices. Besides, oxygen concentration of the combustion gas G introduced into the grinding-type flash dryer 23 is low, that is, approximately 2 to 8 percent, so that there is no danger of explosion of the grinding-type flash dryer 23 and others. [0044] Here, in case that nutlet gas temperature of the grinding-type flash dryer 23 is too high, which may caused by temporary decrease of the quantity of the waste W to the grinding-type flash dryer 23, cooling air C can be introduced upstream from the grinding-type flash dryer 23. [0045] Next, with the dried-material recovery cyclone 27, the ground and dried waste W by the grinding-type flash dryer 23 is recovered, and is returned to the preheater 3 by operating the blower 25. In addition, the recovered waste W can be transported by the blower 25 to apparatus other than the cement hurning apparatus 21, and the waste W can be treated by the apparatus. [0046] On the other hand, the dry exhaust gas G' discharged from the grinding-type flash dryer 23 is returned to an exhaust gas passage, which runs from the lowest cyclone 3Ato the second cyclone 3B through the circulation duct 26 by the fan 28. With this, odorous component included in the dry exhaust gas G' generated after organic sludge and the like is dried can be subject to deodorization treatment. [0047] Meanwhile, although in the embodiment described above, the combustion gas G extracted from the exhaust gas passage, which runs from the lowest cyclone 3A to the second cyclone 3B is fed to the grinding-type flash dryer 23, combustion gases extracted from exhaust gas passages upstream from the second cyclone 3B of the preheater 3, which run from the second cyclone 3B to the third cyclone 3C (temperature of the combustion gas is approximately 700 to 800TO and from the third cyclone 3C to the forth cyclone 3D (temperature of the combustion gas is approximately 550 to 650°C) can also be fed to the grinding-type flash dryer 23. [0048] Further, as to the dry exhaust gas G' also, it is not limited that the gas G' is returned to the exhaust gas passage, which runs from the lowest cyclone 3A to the second cyclone 3B, but the gas G' can be returned to the same area a& in the case that the combustion gaa G described above is extracted. BRIEF EXPLANATION OF DRAWINGS [0049] [Figure l] An outline view showing overall construction of the cement burning apparatus according to the first embodiment of the present invention. [Figure 2] An outline view showing overail construction of the cement burning apparatus according to the second embodiment of the present invention. [Figure 3] An outline view showing overall construction of the cement burning apparatus according to the third embodiment of the present invention. EXPLANATION OF SIGNALS [0050] 1 cement burning apparatus 2 cement kiln 3 preheater 3A lowest cyclone 3B second cyclone 3C third cyclone 3D forth cyclone 4 calciner 5 kiln inlet end 6 dryer 7 fan 8 circulation duct 11 cement burning apparatus 12 cyclone 21 cement burning apparatus 22 cement-raw-material recovery cyclone 23 grinding'type flash dryer 23a rotation shaft 23b strike chains 24 waste storage tank 25 blower 26 circulation duct 27 waste recovery cyclone 28 fan C cooling air D coarse powder G combustion gas G' dry exhavist gas R cement raw material W high-watercontent organic waste (high-water-content organic sludge) CLAIMS [l] A cement burning apparatus comprising a dryer for drying high-water content organic waste of which water content is 10 mass percent or more, wherein combustion gas extracted from one of an exhaust gas passage from a gas outlet to a portion immediately before a material feed portion and a ceiling portion of a preheater cyclone of a cement kiln other than a highest cyclone is fed to said dryer. [2] The cement, burning apparatus as claimed in claim 1, further comprising a coarse powder separator for separating coarse powder from said combustion gas extracted from one of the exhaust gas passage from the gas outlet to the portion immediately before the material feed portion and the ceiling portion, wherein combustion gas from which said coarse powder is separated by the coarse powder separator is fed to the dryer. [3] The cement burning apparatus as claimed in claim I or 2, wherein said dryer is a grinding'type flash dryer, to which the combustion gas is fed so as to directly be contacted with the high-water content organic waste, for drying the organic waste while grinding it. [4] The cement burning apparatus as claimed in claim 1, 2 or 3, wherein dust concentration of said gas that is fed to the dryer is 0.05kg/Nms or more and 0.35kg/Nirr or less. [5] The cement burning apparatus as claimed in one of claims 1 to 4, wherein said high-water-content organic waste is high-water-content organic sludge, [fi] A method of drying high-watercontent organic waste comprising the steps of extracting a part of combustion gas of which dust concentration is in a predetermined range from an exhaust gas passage, which runs from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln) and drying high-water-content organic waste of which water content is 40 mass percent or more by using said part of extracted combustion gas. [7] A method of drying high-water-content organic waste comprising the steps of- extracting a part of combustion gas from an exhaust gas passage, which runs from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln; and adjusting concentration of dust, contained in the extracted combustion gas to a predetermined range; and drying high-water-content organic waste of which water content is 40 mass percent or more by using said gas of which dust concentration is adjusted to the predetermined range. [8] The method of drying high-water-content organic waste as claimed in claim 6 or 7, wherein said part of combustion gas is directly contacted with the high-water-content organic waste, and said high-water-content organic waste is dried while being ground. Is] The method of drying high-water-content organic waste as claimed in claim 6, 7 or 8, wherein dust concentration of said gas used for drying the high-water-content organic waste is 0.05kg/Nm3 or more and 0.35kg/Nm3 or less. [10] The method of drying high-water-content organic waste as claimed in one of claims 6 to 9, wherein said high-water content organic waste is high-water-content organic sludge.

Full Text

SPECIFICATION
CEMENT BURNING APPARATUS AND METHOD OF DRYING HTGH-WATER-CONTENT ORGANIC WASTE
TECHNICAL FIELD [OOOl] The present invention relates to a cement burning apparatus capable of safely and efficiently drying high-water-content organic waste such as high-water-content organic sludge and a method of drying high-watercontent organic waste utilizing the apparatus.
BACKGROUND ART [0002] Conventionally, variety of apparatus and methods for treating waste such as city garbage in cement burning apparatus has been proposed. For instance, in the patent document 1 is disclosed a technology, in which a part of hot air from a clinker cooler is introduced to a dryer for drying waste such as city garbage; gas exhausted from the dryer is returned to the clinker cooler! and the hot air, with which the exhaust gas is mixed, from the clinker cooler is used as air for combustion in a cement kiln or a calciner.
[0003] Further, in the patent document 2, a technology for burning combustible waste in cement burning apparatus is disclosed. In this technology, combustible waste is burned with a part of hot air from a clinker cooler! exhaust gas generated in a waste burning process is aerated to a preheater for heating cement raw material! and slug generated in the waste burning process is extracted.
[0004) However, as described in the above patent documents, the hot air extracted from the clinker cooier can be utilized for drying waste such as city garbage, combustible waste and the like without causing any trouble, but when the hot air is utilized for drying high-watei-content organic waste such as high-water-content-organic

sludge, oxygen concentration of the hot air is high so that there is a danger of explosion. [0005] In addition, even if combustion exhaust gas downstream from the exit of a preheater of a cement burning apparatus was tried to be utilized, since temperature of the combustion exhaust gas in the range was low, that is, 450CC or less, the gas would not be suitable to dry the high-water-content, sludge. On the other hand, gas extracted from the inlet end of a cement kiln is low in oxygen concentration and high in temperature, that is, approximately 1000 "C, so that it is suitable to dry the high-water content organic waste, but extraction of the combustion gas from the inlet end causes a problem that thermal efficiency of the cement kiln decreases. [OOOfi] In consideration of the above problems, the present applicant has eagerly investigated and found that oxygen concentration of the combustion gas extracted from the exhaust gas passage, which runs from the outlet duct of the calciner to the outlet duct of the preheater of the cement kiln is low, that is, 2 to 8 percent, so that there is no danger of explosion, and since temperature of the combustion gas is 450 to 900°C, the high-water-content organic waste can sufficiently be dried and combustion gas is not extracted from the inlet end or the like of the cement kiln, which does not decrease thermal efficiency of the cement kiln. [0007] Patent document l: Japanese Patent Publication Showa 63-151650 gazette
Patent document 2- Japanese Patent Publication 2003-506299 gazette
DISCLOSURE OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION [0008] As described above, in order to dry high-water-content sludge etc., the combustion gas extracted from the exhaust gas passage, which runs from the outlet duct of the calciner to the outlet duct of the preheater of the cement kiln, can be used. Rut, the gas exhausted from the cement kiln as a hot source gas for drying contains

incombustible dust derived from cement raw material, and most of the dust is recovered in dried sludge. In addition, dust concentration of the cement kiln exhaust gas is between approximately 0.05kg/Nm:1 (at an outlet portion of the highest cyclone) find approximately 1.0 kg/Nm3 (at an inlet portion of each cyclone), which means that the concentration considerably varies with area from which the combustion gas is extracted. [00091 Here, the dried sludge containing dust, derived from cement raw material has advantages and disadvantages. An advantage is that the dried sludge containing incombustible dust reduces danger of explosion at a facility for drying. On the contrary, a disadvantage is that the dried sludge containing incombustible dust reduces value of the dried sludge as a fuel,
[0010] In addition to the above, the high-water content organic sludge shapes clumps including 40 mass percent of water or more like clay and its specific surface area is small, which makes it difficult to efficiently dry the organic sludge. [0011] The present invention has been made in consideration of the above problems in the conventional art, and the object thereof is to provide a cement burning apparatus and a method of drying higlvwatercontent organic waste reducing the danger of explosion at the facility for drying; not causing decreased value of the dried sludge as a fuel! and efficiently drying high-water-content organic waste.
MEANS FOR SOLVING PROBLEMS [0012] To achieve the above object, the present invention relates to a cement burning apparatus, and the apparatus is characterized by comprising: a dryer for drying high-watercontent organic waste of which water content is 40 mass percent or more, wherein combustion gas extracted from one of an exhaust gas passage from a gas outlet to a portion immediately before a material feed portion and a ceiling portion of a preheater cyclone of a cement kiln other than a highest cyclone is fed to the dryer.

[0013] In this invention, from one of an exhaust gas passage from a gas outlet to the portion immediately before a material feed portion and a ceiling portion of a preheater cyclone of a cement kiln other than a highest cyclone is extracted a part of combustion gas with low dust concentration, and in a dryer is dried high-watei-content organic waste of which water content is 40 mass percent or more by using the part of combustion gas of low dust content, so that dust content of the organic waste after dried also becomes low, which prevents decreased value of the dried organic waste as a fuel. [0014] The above cement burning apparatus may further comprise a coarse powder separator for separating coarse powder from the combustion gas extracted from one of the exhaust gas passage from the gas outlet to the portion immediately before the material feed portion and the ceiling portion, wherein combustion gas from which the coarse powder is separated by the coarse powder separator is fed to the dryer. With this construction, dust content of the organic waster after dried can be lower, which further increases the value of the dried organic waste as a fuel.
[0015] In the above cement burning apparatus, the dryer can be a grinding-type flash dryer, to which the combustion gas is fed so as to directly be contacted with the high-water-content organic waste, for drying the organic waste while grinding it. With this, improved drying efficiency through increased specific surface area of the high-water-content organic waste and improved grinding efficiency through superficial drying of the high-water-content organic waste can between them exponentially improve overall drying efficiency.
[0016] In the above cement burning apparatus, dust concentration of the gas that is fed to the dryer can be 0.05kg/Nma or more and 0.35kg/Nm3 or less. With this, it becomes possible to reduce the danger of explosion at a facility for drying while preventing decreased value of dried sludge as a fuel.

[0017] In the above cement burning apparatus, the high-watercontent organic waste
may be high-water con tent organic sludge, and paper sludge, sewerage sludge, building
pit sewerage sludge, food sludge and so on may be dried.
[0018] Further, the present invention relates to a method of drying
high-watercontent organic waste, and the method is characterized by comprising the
steps of; extracting a part of combustion gas of which dust concentration is in a
predetermined range from an exhaust gas passage, which runs from an outlet duct of a
calciner to an outlet duct of a preheater of a cement kiln; and drying high-water-content
organic waste of which water content is 40 mass percent or more by using the part of
extracted combustion gas,
[0019] With this invention, since high-watercontent organic waste is dried with a
combustion gas of which dust concentration is in a predetermined range, it becomes
possible to adjust dust concentration of the dried organic waste.
[0020] Further, the present invention relates to a method of drying
high "water-content organic waste, and the method is characterized by comprising the
steps of extracting a part of combustion gas from an exhaust gas passage, which runs
from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln; and
adjusting concentration of dust contained in the extracted combustion gas to a
predetermined range; and drying high-watercontent organic waste of which water
content is 40 mass percent or more by using the gas of which dust concentration is
adjusted to the predetermined range.
[0021] With this invention, since high-watercontent organic waste is dried with a
comhustion gas of which dust concentration is in a predetermined range, it becomes
possible to adjust dust concentration of the dried organic waste.
[0022] In the above method of drying high-watercontent organic waste, the part of the

combustion gas may directly be contacted with the higlrwatercontent organic waste,
and the organic waste can be dried while being ground. With this, as described above,
overall drying efficiency can exponentially be improved.
[0023] \n the above method of drying high-water-eontent organic waste, dust
concentration of the gas used for drying the high-water-content organic waste can be
0.05kg/Nm3 or more and 0.35kg/Nm3 or less. With this, as described above, it becomes
possible to reduce the danger of explosion at a facility for drying while preventing
decreased value of dried sludge as a fuel.
[0024] In the ahove method of drying high-water-content organic waste, the
high"water-content organic waste may be high-water-content organic sludge such as
paper sludge, sewerage sludge, building pit sewerage sludge and food sludge.
EFFECT OF THE INVENTION [0025] As described above, with the present invention, it is possible to provided a cement burning apparatus and a method of drying high-watercontent organic waste reducing the danger of explosion at the facility for drying; not causing decreased value of the dried sludge as a fuel; and efficiently drying high-watercontent organic waste.
THE BEST MODE TO CARRY OUT THE INVENTION [0026] Figure 1 shows a cement burning apparatus according to the first embodiment of the present invention, this cement burning apparatus 1 comprises a cement kiln 2, a preheater 3, a calciner 4, a dryer 6, a fan 7 and others.
[0027] The cement kiln 2, the preheater 3 and the calciner 4 have the same construction as conventional cement burning apparatus, and cement raw material R fed to the preheater 3 is preheated in the preheater 3; calcined in the calciner 4; and burned in the cement kiln 2. [0028] To the dryer 6 is fed high"water-content organic waste (hereinafter referred to

as "waste") W such as high-water-content organic sludge, and to the dryer 6 is fed combustion gas extracted from an outlet portion of the lowest cyclone 3A to dry the waste W. The combustion gas is extracted from a duet from the outlet portion of the lowest cyclone 3A to an inlet, portion of the second cyclone 3B and in the stage before cement raw material fed from the third cyclone 3C is mixed with the combustion gas, so that the combustion gas is low in dust content, that is, approximately 0.15 to 0.351tg/cm3. As a result, when the gas is used for drying the waste W in the dryer 6, dust concentration of the waste W becomes proper, which makes it possible to maintain the dust content of the waste W low while preventing explosion in the dryer 6. [0029] The fan 7 is installed to introduce combustion gas from the preheater 3 to the dryer 6, and exhaust gas from the fan 7 is returned to the exhaust gas passage, which runs from the lowest cyclone 3A to the second cyclone 3B via a circulation duct 8. [0030l Meanwhile, although in the embodiment described above, to the dryer 6 is fed the combustion gas extracted from the outlet portion of the lowest cyclone 3A, not only from the outlet portion of the lowest cyclone 3A, hut combustion gas extracted from a portion selected from a ceiling portion of the lowest cyclone 3A, outlet portions and ceiling portions of the second cyclone 3B, the third cyclone 3C and the forth cyclone 3D can be fed to the dryer 6 to use the combustion gas for drying the waste W, resulting in the same effect as described above.
[0031] Next, a cement burning apparatus according to the second embodiment of the present invention will be explained with reference to Fig. 2. This cement burning apparatus 11 is characterized by comprising, in addition to the construction of the cement burning apparatus 1 shown in Fig. 1, a cyclone 12 aa a coarse powder separator upstream from the dryer 6. Below, to the same composing element as the cement burning apparatus 1 is added the same reference number and the detailed explanation

thereof will he omitted.
[0032] To the cyclone 12 is fed combustion gas extracted from the outlet portion of the lowest cyclone 3A, and coarse power D in the gas is removed. The removed coarse powder D may be returned to the cement burning apparatus 1 and can be treated out of the cement burning apparatus 1. Combustion gas G containing fine powder, which is not recovered by the cyclone 12, is fed to the dryer 6.
[0033] To the dryer 6 is fed the waste W as well as the combustion gas G from the cyclone 12 to dry the waste W. Dust contained in this combustion gas G is collected by the cyclone 12, so that dust content of the gas is low, that is 0.05 to 0.2kg/Nni3, when used for drying the waste W, it becomes possible to maintain the dust content of the waste W low while preventing explosion in the dryer 6.
[0034] Meanwhile, although in the embodiment described above, to the cyclone 12 is fed the combustion gas extracted from the outlet portion of the lowest cyclone 3A, not only from the outlet portion of the lowest cyclone 3A, hut combustion gas extracted from a portion selected from a ceiling portion of the lowest cyclone 3A, outlet portions and ceiling portions of the second cyclone 3B, the third cyclone 3C and the forth cyclone 3D can he fed to the cyclone 12 to use the combustion gas G without coarse powder for drying the waste in the dryer 6, resulting in the same effect as described above. [0035] Next, a cement burning apparatus according to the third embodiment of the present invention will be explained with reference to Fig. 3. This cement burning apparatus 21 is characterized in that the cyclone 12 and the dryer 6 of the cement burning apparatus 11 shown in Fig. 2 are exemplified as a cement-raw-material recovery cyclone 22 and a grinding-type flash dryer 23 respectively and is characterized by further comprising a high-water-content organic waste storage tank (hereinafter referred to as "waste storage tank") 24 and dried organic waste recovery cyclone

(hereinafter referred to as "dried material recovery cyclone") 27 and so on. Below, to the same composing element as the cement burning apparatus 11 is added the same reference number, and the detailed explanation thereof will be omitted. [0036] The cement-raw-material recovery cyclone 22 is installed upstream, from the grinding-type flash dryer 23 to remove dust included in combustion gas G extracted from the exhaust gas passage of the preheater 3 and to feed the combustion gas G of which dust is removed to the grinding-type flash dryer 23.
[0037] The grinding-type flash dryer 23 is installed to dry the waste W fed from the waste storage tank 24 with the combustion gas G fed from the cemenfrawmaterial recovery cyclone 22 while grinding the waste W. This grinding'type flash dryer 23 is provided with a feed opening for the waste W in the upper portion thereof and a feed opening for the combustion gas G from the cement-raw-material recovery cyclone 22 in the lower portion thereof, and the waste W and the combustion gas G are counter-currently contacted with each other. Further, in the grinding-type flash dryer 23 are installed a rotation shaft 23a and strike chains 23b, which are fixed to the rotation shaft 23a and horizontally extend and rotate through centrifugal force together with the rotation of the rotation shaft 23a to grind the waste W.
[0038] The waste storage tank 24 is installed to temporarily store high-water-content organic waste and the high-watercontent organic waste can be high-watercontent organic sludge such as paper sludge, sewerage sludge, building pit sewerage sludge and food sludge.
[0039] A blower 25 is installed to transport the waste W ground and dried by the grinding-type flash dryer 23 to the preheater 3, and a roots blower or the like may be utilized. A fan 28 is installed to return dry exhaust gas G' discharged from the grinding-type flash dryer 23 via a circulation duct 26 to the preheater 3.

[0040] Next, the motion of the cement burning apparatus 21 with the above construction will be explained with reference to figures.
[0041] Cement raw material R is fed to the preheater 3 of the cement hurning apparatus 21, and the raw materia] K. is preheated in the preheater 3; calcined in the calciner 14; and burned in the cement kiln 2. On the other hand, received waste W is temporarily stored in the waste storage tank 24.
[0042] The fan 28 is operated to introd uce the combustion gas G of the cement kiln 2 to the cement-raw-material recovery cyclone 22, and dust included in the combustion gas G is recovered. The recovered dust is returned to the preheater 3, and the combustion gas G from which the dust is recovered is fed to the grinding-type flash dryer 23.
[0043] The waste W from the waste storage tank 24 is fed to the upper portion of the grinding-type flash dryer 23, and the combustion gas G from the cement-raw-materiai recovery cyclone 22 is introduced to the lower portion of the grinding-type flash dryer 23. Since temperature of this combustion gas G is approximately 800 to 9001, high-water-content organic waste can sufficiently be dried. In addition, in the grinding-type flash dryer 23, the waste W and the combustion gas G are directly and counter-currently contacted with each other, and the waste W is dried while being ground by strike chains 23b arranged in the grinding-type flash dryer 23, the waste W is dried from its surface with specific surface area thereof increasing. As a result, in addition to improved drying efficiency due to the increase of the specific surface area, grinding efficiency is also improved due to the dried surface of the waste W, resulting in exponential improvement in overall drying efficiency in comparison to conventional devices. Besides, oxygen concentration of the combustion gas G introduced into the grinding-type flash dryer 23 is low, that is, approximately 2 to 8 percent, so that there is

no danger of explosion of the grinding-type flash dryer 23 and others.
[0044] Here, in case that nutlet gas temperature of the grinding-type flash dryer 23 is
too high, which may caused by temporary decrease of the quantity of the waste W to the
grinding-type flash dryer 23, cooling air C can be introduced upstream from the
grinding-type flash dryer 23.
[0045] Next, with the dried-material recovery cyclone 27, the ground and dried waste
W by the grinding-type flash dryer 23 is recovered, and is returned to the preheater 3 by
operating the blower 25. In addition, the recovered waste W can be transported by the
blower 25 to apparatus other than the cement hurning apparatus 21, and the waste W
can be treated by the apparatus.
[0046] On the other hand, the dry exhaust gas G' discharged from the grinding-type
flash dryer 23 is returned to an exhaust gas passage, which runs from the lowest
cyclone 3Ato the second cyclone 3B through the circulation duct 26 by the fan 28. With
this, odorous component included in the dry exhaust gas G' generated after organic
sludge and the like is dried can be subject to deodorization treatment.
[0047] Meanwhile, although in the embodiment described above, the combustion gas
G extracted from the exhaust gas passage, which runs from the lowest cyclone 3A to the
second cyclone 3B is fed to the grinding-type flash dryer 23, combustion gases extracted
from exhaust gas passages upstream from the second cyclone 3B of the preheater 3,
which run from the second cyclone 3B to the third cyclone 3C (temperature of the
combustion gas is approximately 700 to 800TO and from the third cyclone 3C to the
forth cyclone 3D (temperature of the combustion gas is approximately 550 to 650°C) can
also be fed to the grinding-type flash dryer 23.
[0048] Further, as to the dry exhaust gas G' also, it is not limited that the gas G' is
returned to the exhaust gas passage, which runs from the lowest cyclone 3A to the

second cyclone 3B, but the gas G' can be returned to the same area a& in the case that the combustion gaa G described above is extracted.
BRIEF EXPLANATION OF DRAWINGS [0049] [Figure l] An outline view showing overall construction of the cement burning apparatus according to the first embodiment of the present invention.
[Figure 2] An outline view showing overail construction of the cement burning apparatus according to the second embodiment of the present invention.
[Figure 3] An outline view showing overall construction of the cement burning apparatus according to the third embodiment of the present invention.
EXPLANATION OF SIGNALS [0050] 1 cement burning apparatus
2 cement kiln
3 preheater
3A lowest cyclone 3B second cyclone 3C third cyclone 3D forth cyclone
4 calciner
5 kiln inlet end
6 dryer
7 fan
8 circulation duct

11 cement burning apparatus
12 cyclone
21 cement burning apparatus

22 cement-raw-material recovery cyclone
23 grinding'type flash dryer 23a rotation shaft
23b strike chains
24 waste storage tank
25 blower
26 circulation duct
27 waste recovery cyclone
28 fan
C cooling air
D coarse powder
G combustion gas
G' dry exhavist gas
R cement raw material
W high-watercontent organic waste (high-water-content organic sludge)

CLAIMS
[l] A cement burning apparatus comprising a dryer for drying high-water content
organic waste of which water content is 10 mass percent or more, wherein combustion gas extracted from one of an exhaust gas passage from a gas outlet to a portion immediately before a material feed portion and a ceiling portion of a preheater cyclone of a cement kiln other than a highest cyclone is fed to said dryer.
[2] The cement, burning apparatus as claimed in claim 1, further comprising a
coarse powder separator for separating coarse powder from said combustion gas extracted from one of the exhaust gas passage from the gas outlet to the portion immediately before the material feed portion and the ceiling portion, wherein combustion gas from which said coarse powder is separated by the coarse powder separator is fed to the dryer.
[3] The cement burning apparatus as claimed in claim I or 2, wherein said dryer is
a grinding'type flash dryer, to which the combustion gas is fed so as to directly be contacted with the high-water content organic waste, for drying the organic waste while grinding it.
[4] The cement burning apparatus as claimed in claim 1, 2 or 3, wherein dust
concentration of said gas that is fed to the dryer is 0.05kg/Nms or more and 0.35kg/Nirr or less.
[5] The cement burning apparatus as claimed in one of claims 1 to 4, wherein said
high-water-content organic waste is high-water-content organic sludge,
[fi] A method of drying high-watercontent organic waste comprising the steps of
extracting a part of combustion gas of which dust concentration is in a predetermined range from an exhaust gas passage, which runs from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln) and

drying high-water-content organic waste of which water content is 40 mass
percent or more by using said part of extracted combustion gas.
[7] A method of drying high-water-content organic waste comprising the steps of-
extracting a part of combustion gas from an exhaust gas passage, which runs from an outlet duct of a calciner to an outlet duct of a preheater of a cement kiln; and
adjusting concentration of dust, contained in the extracted combustion gas to a predetermined range; and
drying high-water-content organic waste of which water content is 40 mass percent or more by using said gas of which dust concentration is adjusted to the predetermined range.
[8] The method of drying high-water-content organic waste as claimed in claim 6 or 7, wherein said part of combustion gas is directly contacted with the high-water-content organic waste, and said high-water-content organic waste is dried while being ground. Is] The method of drying high-water-content organic waste as claimed in claim 6, 7 or 8, wherein dust concentration of said gas used for drying the high-water-content organic waste is 0.05kg/Nm3 or more and 0.35kg/Nm3 or less.
[10] The method of drying high-water-content organic waste as claimed in one of claims 6 to 9, wherein said high-water content organic waste is high-water-content organic sludge.

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Patent Number

278631

Indian Patent Application Number

7147/CHENP/2008

PG Journal Number

54/2016

Publication Date

30-Dec-2016

Grant Date

27-Dec-2016

Date of Filing

26-Dec-2008

Name of Patentee

TAIHEIYO CEMENT CORPORATION

Applicant Address

8-1, AKASHICHO, CHUO-KU, TOKYO 104-8518

Inventors:

#	Inventor's Name	Inventor's Address
1	UENO, NAOKI	C/O TAIHEIYO CEMENT CORPORATION, 8-1, AKASHICHO, CHUO-KU, TOKYO 104-8518
2	IZA WA, YOSHIHITO	C/O TAIHEIYO CEMENT CORPORATION, 8-1, AKASHICHO, CHUO-KU, TOKYO 104-8518
3	TOKANO, HIROYUKI	C/O TAIHEIYO CEMENT CORPORATION, 8-1, AKASHICHO, CHUO-KU, TOKYO 104-8518
4	MORI, HIROFUMI	C/O TAIHEIYO CEMENT CORPORATION, 8-1, AKASHICHO, CHUO-KU, TOKYO 104-8518

PCT International Classification Number

C04B7/43

PCT International Application Number

PCT/JP07/62752

PCT International Filing date

2007-06-26

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2007-034206	2007-02-15	Japan
2	2006-177660	2006-06-28	Japan