JP2017149620A - Apparatus for reforming waste gypsum and method for operating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for reforming waste gypsum, which can efficiently reform waste gypsum into anhydrous gypsum while sufficiently suppressing generation of SOx; and to provide a method for operating the reforming apparatus.SOLUTION: An apparatus 100 for reforming waste gypsum includes: a parallel-flow type rotary kiln 10 that includes a burner 12 and heats waste gypsum 30, thereby reforming the waste gypsum into anhydrous gypsum 32; and a supply section 20 that supplies the waste gypsum 30 to the parallel-flow type rotary kiln 10. The supply section 20 is configured to supply the waste gypsum 30 toward a combustion flame 16 of the burner 12.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a waste gypsum reformer and a method for operating the reformer.

  As the number of demolished houses where gypsum board is used increases year by year, the amount of waste gypsum generated has increased. Accordingly, there is an increasing need for techniques for treating waste gypsum. For this reason, various studies have been made to effectively use waste gypsum.

  Waste gypsum usually contains paper and organic admixture together with dihydrate gypsum. For this reason, there is a concern that, if it is added as it is to a cement-based material, the strength development property is lowered or the setting property is fluctuated. Then, the heating reforming apparatus for recovering gypsum content as hemihydrate gypsum or anhydrous gypsum by heating and waste paper gypsum and carbonizing and decomposing paper and an organic admixture is proposed (refer to patent documents 1-7). ).

JP-A-10-230242 JP 2009-102205 A JP 2006-225200 A JP 2009-160507 A JP 2006-199576 A JP 2007-70138 A JP 2007-308343 A

  When the waste gypsum is heated, carbonization and decomposition of the paper and the organic admixture proceed. On the other hand, when the temperature exceeds 1200 ° C., partial decomposition of the gypsum proceeds and there is a concern that SOx is generated. For this reason, when modifying waste gypsum with a conventional reformer, it is necessary to lower the heating temperature as much as possible and lengthen the heating time in order to proceed with the modification of the waste gypsum while suppressing the decomposition of gypsum. was there. For this reason, the production efficiency is low, and the facilities tend to be large in order to secure the residence time.

  Therefore, the present invention provides a waste gypsum reforming apparatus capable of efficiently reforming waste gypsum into anhydrous gypsum while sufficiently suppressing the generation of SOx, and a method for operating the reforming apparatus. For the purpose.

  According to the study by the present inventors, it was found that there is a difference in reaction initiation temperature and reaction rate between carbonization and decomposition reaction of paper and organic admixture and decomposition reaction of gypsum. Based on this knowledge, by supplying waste gypsum toward the burner flame, carbon and organic admixture are quickly carbonized and decomposed before gypsum decomposition occurs, and efficiently converted to anhydrous gypsum. The present inventors have found that this can be done and have completed the present invention.

  That is, the present invention includes, in one aspect, a co-current rotary kiln having a burner and heating waste gypsum to reform it into anhydrous gypsum, and a supply unit that supplies the waste gypsum to the co-current rotary kiln. The supply section provides a waste gypsum reforming device configured to supply waste gypsum toward the burner combustion frame.

  In this reformer, the waste gypsum is supplied toward the combustion flame of the burner, so that the temperature increase rate of the waste gypsum supplied from the supply unit into the cocurrent rotary kiln can be sufficiently increased. Thus, it is presumed that the paper and the organic admixture can be quickly carbonized and decomposed to promote the modification to anhydrous gypsum before the decomposition of the gypsum contained in the waste gypsum occurs. Therefore, waste gypsum can be efficiently modified into anhydrous gypsum while sufficiently suppressing the generation of SOx.

  The waste gypsum is preferably supplied from the supply unit so as to come into contact with the combustion frame. Thereby, the temperature increase rate of the waste gypsum supplied into the cocurrent rotary kiln can be further increased. Therefore, it is presumed that the paper and the organic admixture can be carbonized and decomposed in a shorter time while further improving the conversion to anhydrous gypsum by further suppressing the decomposition of the dihydrate gypsum contained in the waste gypsum.

  The burner is preferably a variable burner capable of adjusting the direction of the combustion frame. As a result, it is easy to find the optimum heating conditions according to the processing amount or properties of waste gypsum, and anhydrous gypsum can be obtained more efficiently.

  The above-mentioned waste gypsum reforming apparatus preferably includes a dust collection unit that collects dust containing anhydrous gypsum contained in the flue gas of the cocurrent rotary kiln. Thereby, the yield of anhydrous gypsum can be improved and productivity can be increased.

  The above-described waste gypsum reforming apparatus preferably includes a dryer for drying the waste gypsum upstream of the supply unit. Thereby, the obtained anhydrous gypsum can be made high quality.

  In another aspect, the present invention includes a co-current rotary kiln having a burner and heating waste gypsum to reform it into anhydrous gypsum, and a supply unit that supplies the waste gypsum to the co-current rotary kiln. A method for operating a reforming apparatus, comprising a step of supplying waste gypsum from a supply section toward a combustion frame of a burner.

  In this reformer operation method, the waste gypsum is supplied to the burner combustion frame, so that the temperature rise rate of the waste gypsum supplied from the supply unit into the cocurrent rotary kiln is sufficiently increased. be able to. Thus, it is presumed that the paper and the organic admixture can be quickly decomposed to promote the modification to anhydrous gypsum before the decomposition of the gypsum contained in the waste gypsum occurs. Therefore, waste gypsum can be efficiently modified into anhydrous gypsum while sufficiently suppressing the generation of SOx.

  In the above step, the waste gypsum is preferably supplied so as to come into contact with the combustion flame. Thereby, the temperature increase rate of the waste gypsum supplied into the cocurrent rotary kiln can be further increased. Therefore, it is presumed that the paper and the organic admixture can be decomposed in a shorter time and the reforming to anhydrous gypsum can be further promoted while further suppressing the decomposition of the gypsum contained in the waste gypsum.

  According to the present invention, a waste gypsum reforming apparatus capable of efficiently reforming waste gypsum into anhydrous gypsum while sufficiently suppressing the generation of SOx, and a method of operating the reforming apparatus are provided. be able to. According to such a reforming apparatus and operation method, since the heating time can be shortened, the reforming apparatus can be sufficiently downsized. Further, since the modification to anhydrous gypsum is promoted, anhydrous gypsum can be obtained with high efficiency even if the reformer is downsized.

It is a schematic diagram which shows one Embodiment of the modification | reformation apparatus of waste gypsum. It is the II-II sectional view taken on the line in the waste gypsum reforming apparatus of FIG. It is a schematic diagram which shows another embodiment of the modification | reformation apparatus of waste gypsum.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings as the case may be. However, the following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted in some cases. The dimensional ratios in the drawings are not limited to the illustrated ratios.

  FIG. 1 is a schematic view showing a waste gypsum reforming apparatus 100 according to this embodiment. The reformer 100 includes a burner 12, and heats the waste gypsum 30 to reform it into anhydrous gypsum 32, a supply unit 20 that supplies the waste gypsum 30 to the cocurrent flow rotary kiln 10, Is provided.

  The co-current rotary kiln 10 is provided with a kiln hood 11, a drum body 17, and a settling chamber 14 in communication from the upstream side to the downstream side. A burner 12 is attached to the kiln hood 11 of the parallel flow rotary kiln 10. A fuel supply unit for supplying fuel is connected to the burner 12 (not shown). As the fuel, any of gaseous fuel (such as city gas), liquid fuel (such as heavy oil), and solid fuel (such as pulverized coal) may be used. From the viewpoint of easy handling, a liquid fuel that generates less dust is preferable.

  The shape and size of the cocurrent rotary kiln 10 are not particularly limited. The length L of the drum body 17 along the direction of the rotation axis is preferably 1 to 10 m, more preferably 2 to 6 m, from the viewpoint of achieving both the downsizing of the reformer and sufficient production capacity. The inner diameter φ of the drum body 17 of the cocurrent rotary kiln 10 is, for example, 1 to 3 m. From the viewpoint of allowing anhydrous gypsum to be discharged in a short time, it is preferable that the inclination angle of the drum body 17 with respect to the horizontal plane is 0.5 to 8 ° and the rotation speed is 1 to 10 rpm. From the same viewpoint, the tilt angle is more preferably 1 to 5 °, and the rotation speed is more preferably 2 to 7 rpm.

  The supply part 20 is comprised by piping, for example. The pipe is inserted into the co-current rotary kiln 10 from the upper wall surface of the kiln hood 11, and the tip thereof is disposed inside the drum body 17. The waste gypsum 30 flows through the piping that forms the supply unit 20 and is supplied into the co-current rotary kiln 10 from the opening at the tip of the piping. The supply unit 20 supplies waste gypsum toward the combustion frame 16 in the drum body 17. The supply unit 20 may be configured to supply the waste gypsum toward the combustion frame 16 by dropping the gypsum by gravity, or to supply the waste gypsum toward the combustion frame 16 by discharging the waste gypsum together with the flowing gas. It may be configured to.

  The burner 12 is preferably a variable burner capable of arbitrarily adjusting the direction of the combustion frame 16. For example, the charged fine particles of the waste gypsum 30 are affected by the air flow, and the time for staying around the combustion frame 16 is short. Therefore, when the waste gypsum 30 has a large amount of fine particles and the modification thereof tends to be difficult to proceed sufficiently, it is effective to adjust the position of the burner 16 so as to easily pass through the combustion frame 16. . It is desirable to appropriately adjust the position of the burner 16 while confirming the quality of the product (anhydrous gypsum). Thus, it becomes easy to find the optimum heating condition by adjusting the direction of the frame to the optimum position according to the particle size of the waste gypsum 30. As a result, it can be more efficiently modified to anhydrous gypsum. As an example of the variable burner, there is one in which the end of the burner is bent with respect to the axis of the burner tube main body, and the direction of the combustion frame can be changed by rotating the burner tube main body around the axis. The variable burner is not limited to such a form, and is not particularly limited as long as the direction of the combustion frame 16 can be changed.

  Waste gypsum 30 contains dihydrate gypsum as a main component. In addition to dihydrate gypsum, the waste gypsum 30 may include hemihydrate gypsum, anhydrous gypsum, and organic substances such as paper and organic admixtures. The content of dihydrate gypsum in the waste gypsum 30 may be, for example, 50% by mass or more, or 60 to 90% by mass. The organic matter content in the waste gypsum 30 may be, for example, 5% by mass or less or 3% by mass or less in terms of carbon content.

  As the waste gypsum 30, for example, waste materials generated at a gypsum board manufacturing factory, gypsum board scraps generated at a new construction site, waste materials generated at a demolition site, and the like can be used. However, waste materials generated at the site of demolition work include inorganic building waste materials other than gypsum. The content of such inorganic building waste is preferably reduced before being supplied into the cocurrent rotary kiln 10. The content of inorganic building waste is preferably less than 10% by mass. In addition, the paper and cloth attached to the surface of the gypsum board are burned by heating in the cocurrent rotary kiln 10. For this reason, it is not necessarily removed before being supplied to the cocurrent rotary kiln 10. However, it may be removed by a known method such as sieving after pulverization.

  The particle size of the waste gypsum 30 is preferably a size that does not cause clogging in the cocurrent flow rotary kiln 10 and can be easily discharged from a silo or a tank. As such a particle size, it is 50 mm or less, for example, Preferably it is 10 mm or less, More preferably, it is 5 mm or less. As a result, handling is improved, and the feeding from the supply unit 20 to the cocurrent rotary kiln 10 can be continued sufficiently stably.

  The supply unit 20 supplies waste gypsum 30 toward the combustion frame 16 of the burner 12. Most of the waste gypsum 30 supplied into the co-current rotary kiln 10 contacts the combustion frame 16 before contacting the inner wall surface of the co-current rotary kiln 10. The waste gypsum 30 may be supplied so as to pass through the combustion frame 16. However, it is not essential that all of the supplied waste gypsum 30 contacts the combustion frame 16 or passes through the combustion frame 16.

  The waste gypsum 30 supplied toward the combustion frame 16 of the burner 12 is heated at a sufficiently high heating rate. As a result, the paper and the organic admixture contained in the waste gypsum 30 in contact with the combustion frame 16 of the burner 12 are quickly carbonized and decomposed. And most of the dihydrate gypsum contained in the waste gypsum 30 is promptly modified into anhydrous gypsum. These reactions can be completed before the gypsum decomposes. Therefore, it is considered that dihydrate gypsum can be efficiently modified to anhydrous gypsum while suppressing the generation of SOx generated with the decomposition of gypsum.

  FIG. 2 is a cross-sectional view taken along the line II-II in the reformer 100 of FIG. A combustion frame 16 is formed in the vicinity of the center in the radial direction on the upstream side of the drum body 17 of the parallel flow rotary kiln 10. The waste gypsum 30 supplied from the supply unit 20 toward the combustion frame 16 passes through the combustion frame 16 and accumulates near the bottom on the upstream side of the drum body 17.

  The waste gypsum 30 that has passed through the combustion frame 16 is exposed to the high temperature of the combustion frame 16 until it has left the periphery of the combustion frame 16 even after being deposited near the bottom of the drum body 17. Waste gypsum 30 that does not come into contact with the combustion frame 16 is also deposited near the bottom of the drum body 17 and then exposed to the high temperature of the combustion frame 16 around the combustion frame 16. By being exposed to high temperature in this way, carbonization and decomposition of paper and organic admixture and reforming to anhydrous gypsum proceed rapidly.

  The drum body 17 continuously rotates in the direction P. Since the rotation axis of the drum body 17 is inclined by 0.5 to 8 ° with respect to the horizontal plane, the upstream side is higher than the downstream side. For this reason, the waste gypsum 30 gradually moves to the downstream side of the drum body 17 while being agitated by the rotation of the drum body 17 of the cocurrent rotary kiln 10.

  The external flame of the combustion flame | frame 16 has the temperature of 1200 degreeC or more which is a gypsum decomposition temperature, for example. Since the decomposition reaction of gypsum does not occur instantaneously, the carbonization and decomposition of the paper and the organic admixture contained in the waste gypsum 30 in contact with the external flame and the waste gypsum 30 that has passed through the vicinity of the external flame can be rapidly advanced. . The waste gypsum 30 is supplied toward the combustion frame 16 by the supply unit 20. For this reason, even if the waste gypsum 30 contains fine particles, the fine particles are suspended by the airflow in the drum body 17 and are sufficiently suppressed from being discharged as dust in the exhaust gas without contacting the combustion frame 16. be able to. The fine particles are instantly reformed by coming into contact with the combustion flame 16 or passing through the vicinity of the combustion flame 16.

  Without contact with the combustion flame 16, the time required for carbonization and decomposition of the paper and organic admixture tends to be longer. When the time for heating becomes longer, the decomposition reaction of gypsum tends to proceed. For this reason, it is preferable that the waste gypsum 30 contacts the combustion frame 16. From the same viewpoint, the temperature of the combustion flame 16 is preferably higher.

  As the residence time of the waste gypsum 30 in the co-current rotary kiln 10 is shorter, the productivity can be improved. However, from the viewpoint of stabilization of anhydrous gypsum quality and production amount, for example, it is 30 seconds or more and less than 10 minutes. Even after the waste gypsum 30 comes into contact with the combustion frame, the kiln bottom temperature in the cocurrent rotary kiln 10 is preferably 500 to 1000 ° C. in order to sufficiently dehydrate the gypsum in the cocurrent rotary kiln 10. The cocurrent rotary kiln 10 preferably has a structure capable of maintaining the above residence time and kiln bottom temperature.

  The anhydrous gypsum 32 (waste gypsum 30) deposited on the bottom of the drum body 17 on the upstream side moves to the downstream side of the drum body 17 while being stirred. As shown in FIG. 1, the anhydrous gypsum 32 generated by heating in the drum body 17 is discharged to the outside of the cocurrent rotary kiln 10 via the settling chamber 14 connected to the downstream side of the drum body 17. . Anhydrous gypsum 32 obtained by modifying dihydrate gypsum contains type II anhydrous gypsum as a main component. In addition to this, one or both of type I anhydrous gypsum and type III anhydrous gypsum may be included. A small amount of hemihydrate gypsum and dihydrate gypsum may remain.

  Anhydrous gypsum 32 is f. CaO (free lime) may be contained, and the content thereof is preferably 1% by mass or less. Thus, f. By reducing the content of CaO, it can be suitably used as a cement-based additive. F. Since CaO is generated when anhydrous gypsum decomposes at high temperature, f. If the content of CaO is low, decomposition of gypsum is suppressed in the cocurrent flow rotary kiln 10, and the amount of SOx generated is sufficiently reduced. In addition, f.CaO is measured by Cement Association standard test method JCAS I-01 “Quantitative method of free calcium oxide”.

  The anhydrous gypsum 32 may contain carbon, and its content (total carbon content) is preferably 0.5% by mass or less. Thus, it can use suitably as a cement-type additive by reducing the total carbon amount. The total carbon content can be measured by the infrared absorption method of JIS R 1603 “Chemical analysis method of fine silicon nitride powder for fine ceramics”.

  FIG. 3 is a schematic view showing another embodiment of the waste gypsum reforming apparatus. The waste gypsum reforming apparatus 110 of FIG. 3 includes incidental facilities on the upstream side and the downstream side in addition to the configuration of the reforming apparatus shown in FIG. A dryer 45 for drying the waste gypsum 30 is provided on the upstream side of the supply unit 20. The waste gypsum once stored in the raw material tank 40 is supplied to the dryer 45. The kind of dryer 45 is not specifically limited, A rotary kiln, a kettle furnace, an airflow drying furnace, a fluidized bed drying furnace, etc. can be illustrated.

  The drying temperature in the dryer 45 is, for example, 70 to 450 ° C. The dryer 45 preferably has a structure capable of realizing such temperature conditions. Waste gypsum dried in the dryer 45 is transferred to the supply unit 20 by the belt conveyor 50. And as the description of the above-mentioned reformer 100, it is supplied from supply part 20 to cocurrent flow type rotary kiln 10, and waste gypsum is reformed to anhydrous gypsum.

  Before the waste gypsum is put into the cocurrent rotary kiln 10, the amount of water in the waste gypsum can be reduced by preliminarily drying the waste gypsum in the dryer 45. As a result, the reforming of the waste gypsum in the cocurrent flow type rotary kiln 10 is promoted, and the carbonization and decomposition of paper and organic matter are also promoted, and the quality of the anhydrous gypsum finally obtained can be improved.

  On the downstream side of the settling chamber 14, a dust collection unit 60, a product silo 70 for storing anhydrous gypsum, and a dust collection unit 60 are provided. The anhydrous gypsum obtained in the cocurrent rotary kiln 10 is transferred to the product silo 70 by the belt conveyor 66.

  On the other hand, the exhaust gas generated in the co-current rotary kiln 10 is introduced into the dust collecting unit 60. Specifically, the flue gas is introduced into the cyclone 62 via the pipe 61, and coarse dust is collected. Exhaust gas from the cyclone 62 is introduced into the electric dust collector 64 via the pipe 63. The electric dust collector 64 collects fine dust that could not be collected by the cyclone 62.

  In this embodiment, since the waste gypsum from the supply part 20 is supplied so that it may contact a combustion flame | frame in the cocurrent flow type rotary kiln 10, the fine particle part is fully reformed. For this reason, the coarse dust and fine dust collected by the dust collection unit 60 both contain anhydrous gypsum as a main component. Accordingly, both of these dusts can be transferred to the product silo 70 by the belt conveyor 66. Thus, by recovering anhydrous gypsum from the flue gas generated in the cocurrent flow type rotary kiln 10, the yield of anhydrous gypsum can be improved and high productivity can be obtained.

  The dust collection unit 60 is not limited to the above-described embodiment, and a known dust collection unit such as a filtration dust collection (bag filter) may be used in addition to the cyclone (centrifugal force dust collector) and the electric dust collector. These dust collectors may be used alone or in combination of two or more.

  The operation method of the reformer 110 includes a step of preheating waste gypsum by the dryer 45, a step of supplying waste gypsum from the supply unit 20 toward the combustion frame 16 of the burner 12, and a waste in the co-current rotary kiln 10. Heating the gypsum to reform it into anhydrous gypsum and recovering dust containing anhydrous gypsum from the flue gas of the cocurrent rotary kiln 10. Each process can be performed based on the above-mentioned description regarding the reformer 100,110.

  In the above-described reforming apparatuses 100 and 110 and the operation methods of these apparatuses, since the reforming of waste gypsum to anhydrous gypsum is promoted, the heating time of the waste gypsum can be shortened without using a large facility. it can. For this reason, the reforming apparatus can be sufficiently miniaturized and the reforming from waste gypsum to anhydrous gypsum can be performed with high efficiency.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment at all.

  The contents of the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

(Examples 1-4)
A waste gypsum reforming device including a cocurrent rotary kiln and a supply unit as shown in FIG. 1 was prepared. Using this reformer, waste gypsum was modified by the following procedure to produce anhydrous gypsum.

  The waste gypsum board was crushed to a size of 4 mm or less to remove a part of the paper, and a granular sample was prepared. Table 1 shows the density, chemical composition, form, and properties of the granular sample. A granular sample (30 g) and water (300 mL) were placed in a beaker, stirred with a hand mixer for 1 minute, and examined for foaming. As a result, it was confirmed that a large amount of foam was generated and foamed. The foaming property indicates that the waste gypsum contains an organic admixture.

  The granular sample was supplied from a supply unit into a co-current rotary kiln (inner diameter φ: 1.4 m, length L: 4.0 m, inclination: 3 °). Recycled heavy oil as a fuel was supplied to the burner in a range of fuel usage of 54 to 77 L / hour, and the kiln bottom temperature of the cocurrent rotary kiln was adjusted as shown in Table 2. As shown in FIG. 1, the granular sample was supplied so that the granular sample and the combustion frame were in direct contact with each other. The supply amount of the granular sample was 1.1 ton / hour. The residence time during which the granular sample stays in the cocurrent rotary kiln was adjusted by changing the rotational speed of the cocurrent rotary kiln. The residence time in each example was as shown in Table 2. In this way, waste gypsum was modified to obtain anhydrous gypsum.

  About the anhydrous gypsum after heat processing, chemical composition (ig.loss, f.CaO, C), gypsum form, and foamability were evaluated. The ignition loss (ig.loss) was measured according to “5.2 Cases other than blast furnace cement and blast furnace slag” in “5. Determination of ignition loss” in JIS R 5202: 2010. f. CaO was measured by Cement Association standard test method JCAS I · 01 “Quantitative method of free calcium oxide”. The gypsum form was confirmed by X-ray diffraction. C (total carbon amount) was measured by the infrared absorption method of JIS R 1603 “Chemical analysis method of fine silicon nitride powder for fine ceramics”. The foamability was evaluated in the same manner as the above granular sample. The evaluation results are as shown in Table 2.

  From the results shown in Table 2, in Examples 1 to 4, although the kiln bottom temperature is as low as 550 to 680 ° C., the ignition loss of waste gypsum and the total carbon amount decrease with a short residence time, and anhydrous gypsum Could be manufactured efficiently. Moreover, since f.CaO was not produced | generated, generation | occurrence | production of SOx accompanying decomposition | disassembly of gypsum was fully suppressed and it was confirmed that anhydrous gypsum is obtained with a high yield.

(Examples 5 to 14)
Using a waste gypsum reformer equipped with a kiln-type dryer (φ: 1.4 m × L: 12.0 m) for drying waste gypsum as shown in FIG. 3 on the upstream side of the kiln supply unit. Was dried and modified to produce anhydrous gypsum. In the kiln type dryer, the drying temperature is set to 260 to 300 ° C. in order to promote the volatilization of crystal water contained in the waste gypsum and sufficiently lower the ignition loss (ig.loss), and the residence time in the kiln type dryer (Drying time) was 20 minutes. The main component of the waste gypsum after drying was hemihydrate gypsum. The ignition loss of waste gypsum after drying was measured in the same manner as the method for measuring the ignition loss of anhydrous gypsum. The measurement results were as shown in Table 3. The waste gypsum after drying was once stored in a storage tank and then modified in the same manner as in Examples 1 to 4 to produce anhydrous gypsum. The kiln bottom temperature and residence time in each example were as shown in Table 3. The anhydrous gypsum obtained in the same manner as in Examples 1 to 4 was evaluated. The evaluation results of the obtained anhydrous gypsum were as shown in Table 3.

  From the comparison results in Table 2 and Table 3, by drying waste gypsum with a dryer before heating with a cocurrent rotary kiln, the loss of ignition and total carbon content of anhydrous gypsum are reduced, and the quality is better. It was confirmed that anhydrous gypsum was obtained. In each example, f. Some CaO was produced, but the amount was very small and there was no problem.

  Provided are a waste gypsum reforming apparatus capable of efficiently modifying waste gypsum to anhydrous gypsum, and a method of operating the reforming apparatus.

DESCRIPTION OF SYMBOLS 10 ... Parallel flow type rotary kiln, 11 ... Kiln food, 12 ... Burner, 14 ... Settling chamber, 16 ... Combustion flame, 17 ... Drum body, 20 ... Supply part, 30 ... Waste gypsum, 32 ... Anhydrous gypsum, 40 ... Raw material tank, 45 ... dryer, 50, 66 ... belt conveyor, 60 ... dust collector, 61, 63 ... piping, 62 ... cyclone, 64 ... electric dust collector, 70 ... product silo, 100, 110 ... reformer.

Claims (7)

A cocurrent rotary kiln having a burner and heating waste gypsum to reform it into anhydrous gypsum;
A supply unit for supplying the waste gypsum to the co-current rotary kiln,
The waste gypsum reforming device configured to feed the waste gypsum toward the combustion frame of the burner.   The waste gypsum reforming apparatus according to claim 1, wherein the waste gypsum is supplied from the supply unit so as to contact the combustion frame.   The waste gypsum reforming apparatus according to claim 1 or 2, wherein the burner is a variable burner capable of adjusting a direction of the combustion frame.   The waste gypsum reforming apparatus according to any one of claims 1 to 3, further comprising a dust collection unit that collects dust containing the anhydrous gypsum contained in the flue gas of the co-current rotary kiln.   The waste gypsum reforming apparatus according to any one of claims 1 to 4, further comprising a dryer for drying the waste gypsum upstream of the supply unit. A cocurrent rotary kiln having a burner and heating waste gypsum to reform it into anhydrous gypsum;
A supply unit that supplies the waste gypsum to the cocurrent rotary kiln, and a method for operating a reformer,
A method for operating a reformer, comprising a step of supplying the waste gypsum from the supply unit toward a combustion frame of the burner.   The operation method of the reformer according to claim 6, wherein the waste gypsum is supplied so as to contact the combustion flame.

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