Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B7/00—Hydraulic cements
  • C04B7/36—Manufacture of hydraulic cements in general
  • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
  • C04B7/47—Cooling ; Waste heat management
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B7/00—Hydraulic cements
  • C04B7/36—Manufacture of hydraulic cements in general
  • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
  • F27B7/20—Details, accessories or equipment specially adapted for rotary-drum furnaces
  • F27B7/2016—Arrangements of preheating devices for the charge
  • F27B7/2025—Arrangements of preheating devices for the charge consisting of a single string of cyclones
  • F27B7/2033—Arrangements of preheating devices for the charge consisting of a single string of cyclones with means for precalcining the raw material

Definitions

• the invention deals with a line for clinker burning - namely for cement clinker - consisting from rotary kiln, to which a clinker air cooler with cooling air input to the cooling area and at least one heated up air output from the cooler is connected and where to this rotary kiln on the front end a pre-heater of powdered raw material, consisting from a system of mutually serially interconnected cyclones eventually in combination with a shaft heat exchanger is situated.
• the clinker after falling out from the rotary kiln can be characterized as a mixture of greater parts, small granules and a great share of dust, all having high temperature closely under the limit for sticking into individual blocks.
• a grate cooler As the most convenient, where the principle here is the exploitation of heat exchange at cross passage of cooling air, which is after acceptance of a certain part of thermal energy led out from the grate cooler area. From point of view of thermodynamics is such exchange less effective as for instance countercurrent heat exchange.
• the stepwise improvement of cement clinker production leads to perpetual decrease of specific heat consumption for clinker burning, and the result of this is the decrease of necessary cooling air volume, which is acquired in the connected cooling equipment, for instance in the mentioned grate cooler, and where such air could be in the next step used as pre heated air in the proper burning process.
• the consequence is that the necessary volume of pre heated burning air is smaller at more efficient burning.
• This has a consequence in excessive increase of burning air temperature, and the inconvenient consequence of this is in regard to the higher working temperature the decreased equipment lifetime, namely in the area of output end of rotary kiln, including the kiln burner and in the area of clinker input to the cooler, eventually also in the area of pre calcination.
• the object of this invention is a line for clinker burning, namely cement clinker, consisting from a rotary kiln, to which a air cooler of clinker is connected, which has a cooling air input to the cooling area and at least one output of heated up air from the cooler, and where to the said rotary kiln front end a raw material pre heater is arranged, where this pre heater is composed from a system of mutually serially interconnected cyclones eventually in combination with a shaft heat exchanger.
• the essence of the invention is that at least one clinker cooler output is with aid of interconnecting tube ended to at least one of the interconnecting tubes of the vertical pre heater middle part, or eventually the interconnecting tube is with aid of a dividing member branched to at least two branches, each one from which is individually ended to one of interconnecting tubes of vertical pre heater middle part.
• An other essence of the invention is - at the line for clinker burning, where the raw material pre heater is divided to two parts, to a high temperature part and to a low temperature part, which are mutually interconnected with a transferring tube - that the cooler is equipped with at least one couple of hot air output, a first hot air output with higher temperature and a second hot air output with lower temperature, whereas the first hot air output is with aid of interconnecting tube ended to at least one from the interconnecting tubes of middle part of vertical pre heater high temperature part and the second hot air output is with aid of additional interconnecting tube ended into the interconnecting tube of middle part of vertical pre heater low temperature part.
• the essence of the invention is also, that the interconnecting tube and/or the additional interconnecting tube are ended into the interconnecting tube of vertical pre heater high temperature part and/or to the interconnecting tube of vertical pre heater low temperature part and this in a place, in which the hot gas temperature, flowing out from the previous level of vertical pre heater of powdered raw material, differs from the temperature of supplied hot air up to 20% as the most, whereas a regulation member is advantageously inserted to the interconnecting a/or additional interconnecting tubes.
• the essence of the invention is also, that the rotary kiln input chamber removal tube into the lower cyclone forms a calcinating channel with fuel addition and with an additional tube of combustion air, which is connected with the grate cooler input area, where the additional tube and the interconnecting tube and/or the additional interconnecting tube are advantageously mutually connected with aid of interconnecting tube, which can be according to the invention equipped with a closing member.
• the embodiment of a construction according to the invention enables the transfer of a part of thermal energy, which is acquired in the clinker cooler and which could be not reasonably used in the burning process, into the raw material pre heating area.
• the heat consumption for the burning is additionally decreased and on the one hand a less thermal and so also operational load of the more exposed areas of burning process and on the other hand the decrease of operational cost to unit production are achieved.
• the line for clinker burning in the construction version according to Fig no. 1 is composed from a vertical pre heater 1 of powdered raw material, from rotary kiln 3 and a grate cooler of burned clinker 4.
• the rotary kiln 3 is supported by rolling support 300 , on its front end the input chamber 30_located and on the kiln is ended with the clinker output 31.
• the vertical pre heater 1 of powdered raw material is composed from a system of one over other located cyclones, from the lower cyclone IT , from the second, third and forth cyclones 12, 13, 14, and from the last upper cyclone 15. All these cyclones are mutually serially connected and they are with a known way interconnected from one hand with the interconnecting tubes of hot gas from 120 to 150, and from the other hand with their output tubes from 121 to 1_51 of powdered raw material such a way, that always the output tube of higher located cyclone - for instance the output tube 131 of third cyclone 13 - is led to the beginning of interconnecting tube of previous couple of cyclones - in the given example into the interconnecting tube 120 of lower cyclone 11 and the second cyclone 12.
• the lower cyclone ⁇ is connected to the input chamber 30 of rotary kiln 3 at one hand with the output tube 11_1 of pre heated powdered raw material and at other hand by removal tube 110 , to which lower part the output tube 121 of pre heated powdered raw material of the consecutive - here of the second cyclone 12_ is ended.
• the output of warm gas from the upper cyclone 15_ is connected with aid of the removal tube 160 to the following, on the Fig no. 1 not demonstrated element of the technological system.
• the input 7_ of pre heated powdered raw material is ended.
• the construction details of individual elements of vertical pre heater 1_ are enough known and they have no influence to the essence of invention and for this reason they are not described in details.
• the output 31_ of rotary kiln 3_ is ended into the input area 41_ of grate clinker cooler 4_, through which also the kiln burner 32_ is led through and where by this burner the technologically necessary operation temperature is achieved and by this also the corresponding technological process in the rotary kiln 3_.
• the grate cooler 4_ is composed from known grate 42_ , which is ended into the input chamber 44_ with pouring out hopper 440 , under which the conveyor 8_ is situated. Under the cooling grate 42_ there is in the body of grate cooler 4_ a system of collecting pits 420 situated.
• grate cooler 4 body is in this example embodiment provided with outputs - with first output 45_ and a second output 46_ of heated up cooling air, from which the first output 45_ is with aid of interconnecting tube 450 connected with the interconnecting tube 130 of vertical pre heater 1_ , further into this tube 450 a regulation element 451 is built in, for instance a butterfly valve.
• the second output 46 is with aid of interconnecting tube 460 connected to the following, for the object of invention not important technological equipment, for instance to a dust removal device.
• FIG. no. 1 is further with dashed line a construction version demonstrated, at which is to the upper part of interconnecting tube 450 , with aid of a dividing member 452 - for instance a regulating valve - a additional branch 453 connected, where this branch is connected to the interconnecting tube 410 , which is ended to the fourth cyclone 14_ .
• the upper part 41_ of grate cooler 4_ is with aid of additional tube 60_ of burning (combustion) air interconnected with the lower part of interconnecting tube 110 , where also the input 61_ of fuel for precalcination is ended.
• additional tube 60_ of burning (combustion) air interconnected with the lower part of interconnecting tube 110 , where also the input 61_ of fuel for precalcination is ended.
• the interconnecting tube 450 and the additional tube 60_ of combustion air could be mutually interconnected with aid of interconnecting tube 62_ , where this could be advantageously provided with a closing member 620 , for instance with a slide valve.
• the vertical pre heater j is divided into two parts, to high temperature part 10_ - composed from three vertically located and mutually serially interconnected cyclones of lower cyclone 11_ , of second cyclone 12_ and of third cyclone 13_ - and to a low temperature part 20_ - which is composed from lowest located shaft exchanger 21_ and from the following couple of cyclones, the lower cyclone 22_ and the upper cyclone 23_ . Both these parts are located in different height so, that input to the shaft exchanger 21_ of the low temperature part 20 is located lower as the output from the highest - third cyclone 13_ of the high temperature part 10_ and the parts are mutually interconnected by the transferring tube 5 of warm gas.
• the demonstration embodiment according to Fig. no. 2 differs - beside the described division of vertical pre heater 1_ to two parts - from the previous one with it that the grate cooler 4_ is provided with a third output 47_ of hot air, which is provided with an output tube 470 and that the second output 46_ of hot air is in this case connected with aid of interconnecting tube 460 - on the Fig no. 2 drawn with dashed line - with the low temperature part 20_ of vertical pre heater 1_ , in the given case with the interconnecting tube 220 , which leads from the shaft exchanger 21_ to the lower cyclone 22_ .
• the output tube 211 of shaft exchanger 21_ is ended to the interconnecting tube 450 , which similarly as at construction according to Fig no.l connects the first output 45_ of grate cooler 4_ with the connecting tube 130 of high temperature part 10 of vertical pre heater 1_ .
• the eventually used regulation element 451 inserted into the interconnecting tube 450 before the mouth of the output tube 211 .
• the function of line for clinker burning is as follows.
• the propre burning is realized in the rotary kiln 3_ , to the input chamber 30_ of which the pre heated powdered raw material is led from the lower cyclone 1_1 with aid of output tube 111 .
• the formed clinker is led from the output 3J_ of rotary kiln 3_ into the input area 41_ of grate cooler 4_ and the clinker passes it with aid of movement of cooling grate 41_ to the output chamber 44_ , from where is with aid of the pouring out hopper 440 led with the conveyor 8_ in direction of arrow T_ for further processing.
• the powdered raw material is led with input 7_ to the lower part of connecting tube 150 of vertical pre heater 1_ and with aid of hot gas - which flows in direction of arrow R_ - at its simultaneous heating up transported to the upper cyclone 15_ .
• connection tubes 140 to 120 and removal tube 110 the powdered raw material is heated up to higher temperature by the hot gases, which are passing in opposite direction of arrows R_ upwards from the rotary kiln 3.
• According to the invention is additionally into the middle part of connecting tube 130 added a part of hot air - from the first output 45_ of grate cooler 4_ with aid of interconnecting tube 450 , where this hot air has arisen as a product of clinker - formed in the rotary kiln 3_ - cooling.
• the location of the interconnection tube 450 mouth can be advantageously chosen so, that the temperature of hot air would differ in this place not excessively from the temperature of hot gases, flowing into the interconnecting tube 130 from the output chamber 30_ of rotary kiln 3_ after passing through the both previous cyclones - the lower cyclone 11 and the second cyclone 12 .
• the connection location is chosen advantageously so that the temperatures of both mediums would not differ more then 20%.
• the quantity of additional warm air from the interconnecting tune 450 can be advantageously regulated for instance depending on the momentary working mode of whole equipment by a regulation element 451 , for instance a clack valve.
• the remaining, not so warm air is removed through the second output 46_ and by to it connected additional interconnecting tube 460 to following process stages.
• the function at construction version according to Fig no.2 is similar.
• the hot gases, coming out from the output chamber 30 of rotary kiln 3_ are passing consecutively in direction of arrows R hrough the high temperature part 10 , the transferring tube 5_ and the low temperature part 20_ .
• the powdered raw material is in this case entered to the low temperature part 20_ by mean of the input 7_ in direction of the arrow V_ and after the first heating up with aid of hot gases flowing through the interconnecting tube 230 in direction of arrow R_ is led to the upper cyclone 23_ . Then it passes in direction of the arrows S_ through the system of output tubes 231 and 121 to the upper part of shaft exchanger 21_ and then to its output tube 211 .
• the interconnecting tube 450 By this tube is then led to the interconnecting tube 450 , by which with aid of the hot air stream is led to the lower part of interconnecting tube 130 of high temperature part 10_ , then it passes through this so, as it is described above. Also here the part of hot air - entered from the first output 45_ of grate cooler 4_ - contributes favorably to the thermal balance of whole equipment and additionally this hot air stream is used for transport of pre heated powdered raw material from the low temperature part 20_ . With the regulation element 451 , which is this case located before the mouth of output tube 211 , the streaming mode of hot air and pre heated powdered raw material in the according part of interconnecting tube 450 can be accommodated.
• the object of invention is not limited to the demonstrated example embodiments.
• the essence of invention is preserved also at application of other versions of pre heaters, for instance at pre heaters with more branches or with other number of heat exchanging stages.
• the number and the connecting places of inputs of additional hot air from the clinker cooling equipment can be different, and similarly the hot air can be led to different places of the powdered raw material pre heater eventually taking into account the temperature of entered air, and this also in connection with the type and construction of applied clinker cooler, which can be of an other version, especially at different type of the produced material, for instance at production of hydraulic lime.
• the construction versions according the invention can be advantageously used at lines for clinker burning, namely at lines with higher capacity and with equipment for precalculation of the raw material before its entering into the rotary kiln.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Furnace Details (AREA)
• Muffle Furnaces And Rotary Kilns (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=5462530

Family Applications (1)

Country Status (5)

Cited By (3)

Citations (3)

Family Cites Families (1)

• 1999
  • 1999-03-19 CZ CZ1999964A patent/CZ292764B6/cs not_active IP Right Cessation
• 2000
  • 2000-03-14 UA UA2001096609A patent/UA67833C2/uk unknown
  • 2000-03-14 RU RU2001128200A patent/RU2209790C2/ru not_active IP Right Cessation
  • 2000-03-14 SK SK1419-2001A patent/SK286042B6/sk not_active IP Right Cessation
  • 2000-03-14 WO PCT/CZ2000/000016 patent/WO2000056678A1/en active Application Filing

Patent Citations (3)

Also Published As

Similar Documents

Legal Events