WO2002004351A1

WO2002004351A1 - Method for granulating calcium chloride hydrate and granulation apparatus

Info

Publication number: WO2002004351A1
Application number: PCT/JP2000/004512
Authority: WO
Inventors: Mitsuhiro Nishimoto; Kazuhito Nishimoto; Takashi Ichimura; Zenji Kato; Masayasu Ito; Satoshi Suwa; Nobuo Sekido
Original assignee: Kaisei Kogyo Co., Ltd.; Aitech Co., Ltd.; Tsukishima Kikai Co., Ltd.
Priority date: 1999-01-13
Filing date: 2000-07-06
Publication date: 2002-01-17
Also published as: JP4298032B2; JP2000203833A

Abstract

In a method for granulating a calcium chloride hydrate wherein seed particles are fluidized in a fluid bed (1) and an aqueous solution of calcium chloride is sprayed from a spray nozzle (8) to the fluidized particles to thereby form granules of calcium chloride hydrate, the partial pressure of water in the fluid bed (1) is adjusted, by controlling a moisture content adjusting device (7) for a fluidizing gas and a concentration adjusting device (9) for an aqueous solution of calcium chloride at least based on measured values from a temperatire sensor T1 for measuring a temperature in the fluid bed (1) and a humidity sensor H3 for measuring a humidity of the discharged gas from the fluid bed (1), so as for the vapor pressure of calcium chloride in the fluid bed (1)to have a value equal to that in the case of a calcium chloride hydrate containing a predetermined number of water molecule at a temperature in the fluid bed (1).

Description

Description Granulation method and granulation device for calcium chloride hydrate

The present invention relates to a method and an apparatus for granulating calcium chloride hydrate, which form granules of calcium chloride hydrate by a fluidized bed. Background art

Conventionally, as a method and an apparatus for producing a granulated product of calcium chloride hydrate, a calcium chloride aqueous solution is introduced into a flake force to produce a flake-like granulated product, or a rotating disk or the like is used to generate granules in the air. There has been used a method of generating granular granules by solidifying by scattering into particles.

However, in such a granulating method and a granulating apparatus, when a breaker is used, the shape of the granulated material is limited to a flake shape, whereas when the granulated material is scattered in the air, the granulated material is granulated. There was a problem that the shape of the particles was greatly distorted and the particle size distribution was extremely large, and a large space was required to solidify the scattered calcium chloride aqueous solution. In addition, when using these flakers or when dispersing the aqueous calcium chloride solution into the air, to ensure that the supplied aqueous calcium chloride solution is solidified, the aqueous calcium chloride solution must be heated to about 180 ° C or higher in advance. and _t must therefore be concentrated to the molten salt state of about 7 0 wt% or more concentration, in these methods, the need high-temperature heating means and heat source order to concentrate this way an aqueous solution of calcium chloride in a high concentration Of course, measures must be taken against corrosion, etc., because high-temperature and high-concentration calcium chloride aqueous solutions are handled.

On the other hand, in the field of pharmaceuticals such as foods and pharmaceuticals, a granulation method and apparatus have been proposed in which a binder solution or the like is sprayed while fluidizing seed particles using a fluidized bed to produce granules. However, there are calcium chloride hydrates in which the number of water molecules to be hydrated is 1, 2, 4, or 6, and the above granulation method and granulation apparatus are simply applied to granulation of calcium chloride hydrate. Calcium chloride aqueous solution while flowing calcium chloride particles It is impossible to obtain calcium chloride hydrate with a predetermined number of water molecules only by spraying the liquid.

The present invention has been made under such a background, and it is not necessary to heat an aqueous solution of calcium chloride to a high concentration by heating it at a high temperature, and it is possible to produce granules having a predetermined number of water molecules. It is an object of the present invention to provide a method and an apparatus for granulating calcium hydrate. Disclosure of the invention

Here, the inventors of the present invention indicate that the vapor pressure of these calcium chloride hydrates in the fluidized bed is determined based on a predetermined vapor pressure diagram corresponding to the number of water molecules. We focused on the fact that the vapor pressure becomes a predetermined value with respect to the temperature. In other words, by appropriately setting the relationship between the temperature in the fluidized bed and the vapor pressure of calcium chloride, calcium chloride hydrate having a predetermined number of water molecules can be obtained based on the vapor pressure diagram. is there. Thus, the granulation method of the present invention has been made based on such knowledge, and thus a calcium chloride hydrate that forms granules by spraying an aqueous calcium chloride solution while fluidizing seed particles in a fluidized bed. The method for granulation according to the above, wherein when the relationship between the temperature in the fluidized bed and the vapor pressure of calcium chloride is appropriately set as described above, the partial pressure of the steam in the fluidized bed is adjusted so that The vapor pressure of calcium chloride is set to the vapor pressure of calcium chloride hydrate having a predetermined number of water molecules with respect to the temperature in the fluidized bed.

Therefore, according to the granulation method of calcium chloride hydrate configured as described above, since the sprayed calcium chloride aqueous solution adheres to the seed particles flowing in the fluidized bed and granulates, the dilute aqueous solution is formed. It is possible to produce a granulated product by using this method, and even if the temperature in the fluidized bed is relatively low, by adjusting the partial pressure of steam in the fluidized bed, this temperature can be adjusted to this temperature in the vapor pressure diagram. The vapor pressure of calcium chloride can be set to a corresponding appropriate vapor pressure, and it is possible to granulate calcium chloride hydrate having a predetermined number of water molecules. The above-mentioned seed particles are sprayed, such as particles of hydrated calcium chloride dihydrate, calcium chloride monohydrate, anhydrous calcium chloride, or a mixture thereof, in which the number of water molecules to be hydrated is 2 to 0. In addition to the same calcium chloride particles as the aqueous solution, Particles such as thorium and magnesium chloride may be used as seed particles.

Here, when adjusting the partial pressure of steam in the fluidized bed, it is possible to adjust the moisture content of the fluidizing gas supplied to the fluidized bed. In addition, it is also possible to adjust the partial pressure of steam in the fluidized bed by adjusting the concentration of the aqueous calcium chloride solution supplied to the fluidized bed together or alone. Further, in order to more accurately adjust the partial pressure of water vapor in the fluidized bed, at least the temperature in the fluidized bed and the exhaust humidity from the fluidized bed are measured. It is desirable to control the partial pressure.

In addition, the granulation method using the above-mentioned flaker and the method of scattering into the air can only produce granules having a specific shape, respectively.However, in the above-described granulation method using a fluidized bed, calcium chloride is used. By adjusting the spray height at which the aqueous solution is sprayed, it is possible to generate granules having a predetermined shape. That is, according to the results obtained from various experiments, the spray height is set relatively high (for example, 300 mm or more) with respect to the height of the fluidized bed in the stationary bed. The aqueous calcium chloride solution becomes droplets and adheres to the surface of the seed particles, resulting in the formation of granules containing confetti-shaped particles. If the spray height is set to a relatively low value (for example, less than 300 MI, preferably less than 280 bandages), the aqueous solution of calcium chloride uniformly adheres to the surface of the seed particles, so that round particles are formed. Can be produced.

On the other hand, by adjusting the partial pressure of water vapor in the fluidized bed with respect to the vapor pressure of calcium chloride in the fluidized bed, a granulated product having a predetermined shape can be generated in this manner. For example, if the above water vapor partial pressure is made sufficiently lower than the calcium chloride vapor pressure, as in the case where the spray height is increased, the particles in the shape of confetti are increased, and conversely, the water vapor partial pressure is reduced to the calcium chloride vapor pressure. If it approaches, the number of round particles increases.

Further, since only particles within a predetermined particle size distribution range can be used as a product as they are among the granules thus produced, the calcium chloride aqueous solution produced in the fluidized bed is generally used. It is desirable that the granules of the Japanese product be separated into coarse particles having a particle size larger than the above range, medium particles having a particle size within the above range, and fine particles having a small particle size.In this case, the coarse particles crush the particles. And at least with fine particles It is efficient to circulate through the fluidized bed to make new seed particles. However, the ratio of the total weight of calcium chloride hydrate discharged from the fluidized bed to the weight of the above-mentioned medium particles that are separated into a product, that is, the circulation ratio of the generated calcium chloride hydrate is 1.5. It is desirable to set the value in the range of ~ 10.If the circulation ratio exceeds the above range, the number of circulating particles increases and the number of medium particles separated as a product decreases, while the circulation ratio falls below the above range. This may lead to a shortage of seed particles supplied to the fluidized bed. When separating the granules in this way, it is efficient to separate the granules using at least two inclined vibrating sieves. In the case of shaping irregularly shaped particles, the present invention can be applied to shape spines, round particles, or the like without circulating the particles.

On the other hand, the granulation apparatus of calcium chloride hydrate of the present invention performs granulation of calcium chloride hydrate by the above granulation method more reliably, that is, while the seed particles are fluidized in the fluidized bed. An apparatus for granulating calcium chloride hydrate for producing granulated material by spraying an aqueous solution of calcium chloride, comprising: a temperature sensor for measuring a temperature in the fluidized bed; A humidity sensor for measuring the exhaust humidity of the gas, and by adjusting the partial pressure of water vapor in the fluidized bed by control based on at least the measurement results of the temperature sensor and the humidity sensor, the vapor pressure of calcium chloride in the fluidized bed. Is set to the vapor pressure of calcium chloride hydrate having a predetermined number of water molecules with respect to the temperature in the fluidized bed.

Here, when adjusting the partial pressure of water vapor in the fluidized bed in this way, one of the above-mentioned fluidized beds is provided with a moisture adjusting device for adjusting the moisture amount of the fluidizing gas supplied to the fluidized bed. In addition, the moisture adjusting device includes a flow rate sensor for measuring the amount of moisture given to the fluidizing gas, a temperature sensor and a humidity sensor for measuring the temperature and humidity of the moisture-regulated flowing gas, It is possible to adjust the water content of the flowing gas by controlling at least based on the measurement results of the flow rate sensor, temperature sensor, and humidity sensor and the measurement results of the temperature sensor and humidity sensor provided in the fluidized bed. It is. In addition, the fluidized bed is provided with a concentration adjusting device for adjusting the concentration of the calcium chloride aqueous solution supplied to the fluidized bed in accordance with this or alone, and the concentration adjusting device is provided with a concentration-adjusted device. Calcium chloride aqueous solution A concentration sensor and a flow rate sensor for measuring the concentration and the flow rate of the liquid, and the control is performed based on at least the measurement results of the concentration sensor and the flow rate sensor and the measurement results of the temperature sensor and the humidity sensor provided in the fluidized bed. It is also possible to adjust the concentration of the calcium aqueous solution.

By the way, the aqueous solution of calcium chloride sprayed on the fluidized bed in this granulator depends on the concentration and temperature, and when the granulation in the fluidized bed is temporarily stopped or the granulation operation is completed, If it stays in the pipes inside it, it tends to be clogged and clogged easily, and when consolidation occurs, the portion clogged by this consolidation must be melted the next time granulation work is resumed. Therefore, it is desirable to provide a caking preventing means so that caking of the calcium chloride aqueous solution does not occur even when such granulation is stopped. Here, when the calcium chloride aqueous solution is adjusted to a predetermined concentration in a tank and supplied from the tank to the fluidized bed through a supply pipe and sprayed, consolidation occurs in the supply pipe. First, as the above-mentioned consolidation preventing means, first, it is desirable that a return pipe for returning the aqueous solution of calcium chloride in the supply pipe to the tank can be connected to this supply pipe, and granulation was stopped. In this case, the calcium chloride aqueous solution in the supply pipe may be returned to the tank via the return pipe so that the calcium chloride aqueous solution does not remain in the supply pipe.

Also, for example, if there is a long time after the completion of the granulation operation until the next granulation operation is resumed, the calcium chloride aqueous solution may solidify in the above-mentioned tank, but after such a granulation operation is completed. It is not economical, for example, to keep the entire amount of the aqueous solution of calcium chloride held in this tank heated until the end of the granulation operation in order to prevent caking of the powder. On the other hand, the granulating apparatus is usually provided with a scrubber for washing the exhaust gas discharged from the fluidized bed with washing water and recovering the calcium chloride component in the exhaust gas. Since the calcium chloride solution in which the calcium chloride component in the exhaust gas is dissolved is retained, the above-mentioned tank can be connected to this scrubber as the above-mentioned caking prevention means. It is desirable that the aqueous solution of calcium chloride in the tank can be supplied to the scrubber so that it can be held. Flow

6

It is economical because it is possible to collectively heat and hold the shim aqueous solution. When the granulation operation is restarted, the aqueous calcium chloride solution may be returned from the scrubber to the tank and sprayed on the fluidized bed.

Further, a seed hopper for supplying seed particles to the fluidized bed is connected to the fluidized bed, and the seed particles are supplied from the seed hopper when granulation is performed for the first time such as when the granulation operation is restarted. However, in addition to directly circulating at least a portion of the granulated calcium chloride hydrate formed in the fluidized bed into the fluidized bed to form seed particles as described above, the seed hopper is selectively used. If it is possible to supply the granulated material to the seed hopper before the end of the granulation work, for example, the granulated material can be supplied and stored in the seed hopper, and then supplied to the fluidized bed as seed particles when the next granulation work is restarted. It is efficient because there is no need to prepare seed particles again. Further, in some cases, a granulated product having a large particle size among the granulated calcium chloride hydrates may be required as a product, and thus the chloride formed in the fluidized bed may be added to the fluidized bed. A vibrating sieve device that separates the granulated calcium hydrate into coarse, medium, and fine particles is connected, and at least a portion of the coarse particles can be selectively discharged as product granules. It is desirable to do so.

Furthermore, in the case where a scrubber is connected to the fluidized bed as described above, the washing water for cleaning the exhaust gas can be circulated to the scrubber, and at least a part thereof is supplied to the fluidized bed side. It is desirable that the scrubber can concentrate and supply the aqueous solution of calcium chloride to the fluidized bed side and spray it in the scrubber, so that it is easy to adjust the concentration in the above tank during the granulation operation. On the other hand, for example, even when the aqueous solution of calcium chloride is concentrated before resuming the granulation operation, the scrubber, instead of the above-mentioned tank, uses the high-temperature exhaust gas discharged by drying and raising the temperature of the fluidized bed. The aqueous solution can be concentrated in advance, and the concentrated aqueous solution of calcium chloride can be stored in a tank or a moving bed. Since it is possible to directly supply, it is possible to shorten the concentration time. In addition, the scrubber is a spray type scrubber in which exhaust gas discharged from the fluidized bed is introduced into a washing tower and washed with washing water sprayed into the washing tower, so that a gas flow rate to be treated is reduced. Exhaust blower with reduced pressure loss Power can be reduced. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a view showing a first embodiment of a granulator of calcium chloride hydrate of the present invention.

FIG. 2 is a vapor pressure diagram of calcium chloride hydrate.

FIG. 3 is a view showing a second embodiment of the granulation device for calcium chloride hydrate of the present invention.

FIG. 4 is a cross-sectional view of the first and second dampers 24 and 25 of the granulator of the second embodiment shown in FIG.

FIG. 5 is a cross-sectional view showing a reservoir 28 of the granulating apparatus according to the second embodiment shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a first embodiment of a granulation device for calcium chloride hydrate according to the present invention. In this figure, reference numeral 1 denotes a fluidized bed, at the bottom of which a pressurizing chamber 3 is formed via a dispersing plate 2, and a pressurizing blower 4 and an incineration A hot blast stove 6, which is provided with a blower 5 and supplies heated gas for flow, is connected via a moisture adjusting device 7. A spray nozzle 8 is suspended above the dispersion plate 2 in the fluidized bed 1 so as to be movable up and down. The spray nozzle 8 is provided with a calcium chloride aqueous solution tank 10 having a concentration adjusting device 9. Connected via feed pump 11. Further, a seed hopper 12 is connected to the fluidized bed 1, and seed particles of calcium chloride hydrate can be supplied into the fluidized bed 1 from slightly above the dispersion plate 2. The seed particles include particles of calcium chloride dihydrate, calcium chloride monohydrate, anhydrous calcium chloride, and mixtures thereof, as well as particles of sodium chloride and magnesium chloride. It may be.

Here, in the present embodiment, the moisture adjusting device 7 radiates or sprays steam or water to the heated and dried fluidizing gas supplied from the hot blast stove 6 to the pressurized chamber 3 of the fluidized bed 1. Thus, the moisture content of the flowing gas, that is, the humidity is determined. It is configured to be adjustable to a fixed value. The amount of steam or water supplied

The (flow rate) is measured by the flow rate sensor F, and the temperature and humidity of the flowing gas whose moisture has been adjusted by the moisture adjusting device 7 are measured by the temperature sensor 1 ^ and the humidity sensor H, respectively.

The concentration adjusting device 9 is configured such that a steam pipe through which high-temperature steam is supplied is arranged in the above-mentioned tank 10 where the raw material calcium chloride can be supplied. The retained calcium chloride aqueous solution is heated to evaporate water, and the concentration is adjusted to a predetermined value. Note that thus adjusted concentration of calcium chloride aqueous solution fed to the re-spray nozzle 8 by the feed pump 1 1 is concentration sensor D, by the re-supply amount Li by the flow sensor F _2, each measured You. Further, the temperature sensor T ₂ temperature in the fluidized layer 1, the humidity by the humidity sensor Eta _2, are respectively measured, the humidity of the exhaust gas discharged from the fluidized bed 1 is measured further by the humidity sensor Eta _3.

On the other hand, a vibrating sieve device 14 is connected to the outlet of the granulated material in the fluidized bed 1 via a packet elevator 13. This vibrating sieve device 14 is provided with a plurality of sieve nets, each having a smaller mesh size from the upper stage to the lower stage, each of which is inclined with respect to a horizontal plane and is provided so as to be vibrated by a vibrating device. The granulated product supplied from 3 can be separated into medium particles within a predetermined range of particle size distribution, which are regarded as products, coarse particles having a larger particle size and fine particles having a smaller particle size. The number of sieves, the size of the mesh, the angle of inclination with respect to the horizontal plane, and the like are appropriately set according to the size and shape of the particles of the granulated material to be separated as a product.

A crusher 15 is connected to the upper stage of the vibrating sieve device 14 so that coarse particles larger than a predetermined particle size distribution, which are separated by being sieved through the upper sieving net, can be crushed. The coarse particles pulverized in this manner are partially passed through the lower sieve screen of the vibrating sieve device 14 and separated into a part of the medium particles within a predetermined particle size distribution range, and the predetermined particles having passed through the upper and lower sieve screens. Along with the fine particles smaller than the particle size distribution, the particles are returned through the supply path from the seed hopper 12 and can be circulated to the fluidized bed 1. The remainder of the above-mentioned medium particles is supplied to the drying cooler 16 to be subjected to an anti-caking treatment, and is discharged as a product. Further, the humidity sensor H ₃ is the outlet of the fluidized bed 1, which is provided, in the present embodiment is connected to the scrubber 1 7 Benchiyuri type as shown in FIG. 1, the exhaust gas discharged from the fluidized bed 1, After the scrubber 17 is washed with washing water to remove fine calcium chloride particles contained in the exhaust gas, the exhaust gas can be exhausted by an exhaust blower 18. The scrubber 17, which has taken in the fine chlorinated calcium particles in the exhaust gas, is circulated as scrubber 17 by the scrubber pump 19, and part of the scrubber 17 is added with the raw material calcium chloride. As a result, the aqueous solution can be circulated to the tank 10 as an aqueous solution of calcium chloride sprayed on the fluidized bed 1.

Next, an embodiment of the granulation method of the present invention when a granulated product of calcium chloride hydrate is produced using the granulator configured as described above will be described. In the present embodiment, first, the air pushed into the hot blast stove 6 from the pushing blower 4 is heated to a predetermined temperature by the heat generated by burning the fuel with the air from the incineration blower 5, and dried in a dry state. It is sent to the adjusting device 7. After the dried air is adjusted to a predetermined moisture content by adding steam or water in a moisture adjusting device 7, the dried air is usually heated at a high temperature of about 120 to 180 ° C. It is supplied to the pressurized chamber 3 of the fluidized bed 1 as a working gas and is ejected from the dispersion plate 2 to flow the calcium chloride seed particles held in the fluidized bed 1. As the seed particles, those supplied from the seed hopper 12 are used in the early stage of the operation of the granulator or when there is a shortage of particles in the fluidized bed 1, and the granulator is usually used. During operation, fine particles circulated from the vibrating sieve device # 4, some medium particles, and coarse particles crushed by the crusher 15 are used.

On the other hand, in the fluidized bed 1, a spray nozzle 8 is appropriately moved up and down to be arranged at a predetermined spray height, and a calcium chloride aqueous solution whose concentration has been adjusted by the concentration adjusting device 9 is supplied to a tank 10. Is supplied by a supply pump 11 and sprayed from the spray nozzle 8. However, the concentration of the aqueous solution of calcium chloride adjusted by the concentration adjusting device 9 is lower than that of the conventional molten salt state, and it is as low as about 5 wt% to as high as 60%. And usually about 37-53 wt%. And the calcium chloride sprayed in this way The aqueous solution adheres to the surface of the flowing seed particles and dries, and enlarges the seed particles to form granules.

Here, in the present embodiment, while the moisture of the fluidizing gas supplied to the fluidized bed 1 is adjusted by the moisture adjusting device 7, the moisture of the aqueous solution of calcium chloride sprayed into the fluidized bed 1 is adjusted by the concentration adjustment. The concentration of the aqueous solution is adjusted by the device 9, that is, the amount of water supplied to the fluidized bed 1 is adjusted. Thus, the partial pressure of water vapor in the fluidized bed 1 can be adjusted. Therefore, by adjusting the partial pressure of water vapor in the fluidized bed 1, the chloride pressure in the fluidized bed 1 is adjusted based on the vapor pressure diagram according to the number of water molecules of calcium chloride hydrate as shown in FIG. The vapor pressure of calcium is set to the vapor pressure of calcium chloride hydrate having the number of water molecules to be granulated in accordance with the temperature in the fluidized bed 1.

That is, for example, when the temperature of the fluidized bed 1 is 9 0 ° C, calcium chloride vapor pressure when generating the calcium chloride dihydrate _{(C a CI 2 · 2 H} 2 0) is 5.3 The partial pressure of water vapor in the fluidized bed 1 is adjusted by the water adjusting device 7 and the concentration adjusting device 9 so as to be set at about kPa (40 band Hg). Note that, in this embodiment, the setting of the vapor pressure of calcium chloride in the fluidized bed 1 by adjusting the water vapor partial pressure is performed by the temperature sensor T ₂ , the humidity sensor,, the flow rate sensor F, F ₂ , and the like. Preferably, it is automatically controlled based on the measurement results obtained by the concentration sensor D. Further, in the above granulating apparatus, the spray nozzle 8 for spraying the aqueous solution of calcium chloride on the seed particles flowing in the fluidized bed 1 can be moved up and down. The spray height for spraying the aqueous solution of calcium chloride is adjustable. However, when the spray height is relatively high, the sprayed calcium chloride aqueous solution becomes fine droplets, adheres to the surface of the seed particles and dries, whereby the calcium chloride granulated is formed. The hydrate has a spinous shape in which protrusions are formed on the surface of the round particles in some places. On the other hand, when the spray height is relatively low, the sprayed calcium chloride aqueous solution adheres entirely to the surface of the seed particles and dries, producing round particles having a smooth surface. The Rukoto.

Next, the granules thus generated in the fluidized bed 1 are transferred to the bucket conveyor 1. 3 into the vibrating sieve device 14 and sieved by a plurality of inclined vibrating sieves, coarse particles having a larger particle size than a predetermined particle size distribution range, and medium particles within a predetermined particle size distribution range. However, it is classified into fine particles having a smaller particle size than this range. Then, as described above, the coarse particles are pulverized by the pulverizer 15 and returned to the fluidized bed 1 together with the fine particles and some of the medium particles, while the remaining medium particles are consolidated by the drying cooler 16. Prevention treatment is applied and discharged as granulated calcium chloride hydrate as a product. Further, the exhaust gas discharged from the fluidized bed 1 is discharged after the fine calcium chloride particles are collected and removed by the scrubber 17, and the washing water of the scrubber 17 in which the fine chloride particles are dissolved. Some of the water is returned to tank 10 and circulated.

However, in such a method of granulating calcium chloride hydrate, first, an aqueous solution of calcium chloride is sprayed on the seed particles flowing in the fluidized bed 1 and adhered to the surface thereof, and this is heated. Drying with an application gas produces re-granulated material, so there is no need to concentrate the aqueous calcium chloride solution to a molten salt state, unlike the conventional method using a flaker or the method of scattering in air. Granulation is possible using a dilute aqueous solution, and there is little danger of equipment corrosion, and there is no need for a heating means to concentrate this aqueous solution to a high concentration. In addition, according to the vapor pressure diagram of calcium chloride hydrate shown in FIG. 2, chlorides 2, 4, and 6 hydrates, which are generally used as products, have the following characteristics. If the temperature of the fluidized bed 1 is relatively low, for example, about 60 to 150 ° C., granulation can be performed by appropriately setting the vapor pressure. By heating the flowing gas such as air, the temperature can be raised relatively easily or maintained stably.

In the above granulation method, the number of water molecules of a predetermined calcium chloride hydrate to be granulated is adjusted by adjusting the partial pressure of steam in the fluidized bed 1 according to the temperature in the fluidized bed 1. The vapor pressure of the calcium chloride hydrate in the fluidized bed 1 can be set to the vapor pressure according to the above, whereby calcium chloride hydrate having a desired number of water molecules can be generated. Therefore, according to the method for granulating calcium chloride hydrate having the above structure, the granulated calcium chloride hydrate having an appropriate number of water molecules according to the use as a product is obtained. Can be reliably manufactured, and the subsequent processing can be performed efficiently and simply.

Here, in the present embodiment, in adjusting the water vapor partial pressure in the fluidized bed 1 in this manner, the moisture amount of the fluidizing gas supplied to the fluidized bed 1 by the moisture adjusting device 7, that is, The humidity is adjusted, and the concentration of the aqueous calcium chloride solution sprayed and supplied into the fluidized bed 1 is adjusted by the concentration adjusting device 9 described above. It is also possible to configure so that the partial pressure of water vapor is adjusted. However, especially if it is attempted to adjust the water vapor partial pressure only with the concentration adjusting device 9, the responsiveness to fluctuations in the temperature in the fluidized bed 1 may be insufficient, so the temperature in the fluidized bed 1 may be insufficient. The water content of the flowing gas is adjusted by the moisture adjusting device 7 while maintaining the concentration of the aqueous solution of calcium chloride sprayed by the concentration adjusting device 9 at an appropriate concentration in accordance with the time. It is desirable to adjust the water vapor partial pressure in the fluidized bed 1 by using the adjusting device 7 and the concentration adjusting device 9 together.

Further, in the present embodiment, the flow rate of steam or water supplied to the moisture adjusting device 7, the temperature and humidity of the flowing gas whose moisture has been adjusted, and the concentration and flow rate of the aqueous calcium chloride solution adjusted by the concentration adjusting device 9. further humidity of the exhaust gas from the fluidized bed 1 and the temperature and humidity in the fluidized bed 1, respectively the temperature sensor 1 ^, T _2, humidity sensors Eta, ~ ^! ^ Flow sensor F ,, F _2, and the density sensor D, and measured by. From the measurement results of at least the temperature in the fluidized bed 1 and the exhaust humidity from the fluidized bed 1, the vapor pressure of chloridized calcium hydrate is determined based on the vapor pressure diagram of calcium chloride hydrate described above. It is possible to reliably adjust the water vapor partial pressure so that it is optimally set. In addition, in the present embodiment, the temperature and humidity (water content) of the flowing gas, the concentration and the flow rate of the calcium chloride aqueous solution, and the flow rate of the calcium chloride aqueous solution are automatically determined using a computer or the like based on the measurement results obtained by other sensors. By controlling the water vapor pressure, it becomes possible to adjust the water vapor partial pressure more accurately.

On the other hand, in the above granulating apparatus, the spray nozzle 8 for spraying the aqueous solution of calcium chloride is capable of moving up and down as described above, and the spray height of this aqueous solution of chlorinated calcium is set to an appropriate height. By this, the predetermined shape according to the spray height Is produced. In other words, when the spray height is relatively low, the aqueous solution of chlorinated calcium is uniformly and uniformly adhered to the surface of the seed particles in a liquid state, so that the granules are formed into round particles. On the other hand, when the spray height is relatively high, the sprayed calcium chloride aqueous solution becomes droplets and adheres to the surface of the seed particles in a dotted manner. The granules are formed into particles in the shape of confetti. Therefore, for example, when the formed granules of calcium chloride hydrate are used as a hygroscopic material, the latter, such as the confetti-shaped granules, secures a sufficient space around the particles and absorbs moisture. On the other hand, the former round granulated material has a higher packing ratio per unit volume than the former, and can exhibit stable moisture absorption over a long period of time. That is, it is possible to obtain a granulated material having a shape suitable for the purpose.

Note that whether the granulated particles have a spinous shape or a round shape depends on the concentration and supply amount of the aqueous solution of calcium chloride, the shape and size of the spray nozzle 8, and the seeds held in the fluidized bed 1. It is expected that it is affected by the amount of particles and the superficial velocity of the fluidizing gas, but as a result of experiments in which the spray height was varied under various conditions, When the spray height was set to 30 Omni or more, it was confirmed that spinous particles were remarkably generated. However, this does not mean that all particles will have a spinous shape when the spray height is set to the above range, and that the particles will have a spinous shape when the spray height falls below the above range by even 1 mm. This does not mean that no particles are produced at all, and that when the spray height is set within the above range, the proportion of particles in the shape of confetti in the produced granules has increased significantly; is there.

On the other hand, in order to generate a granulated product containing particles of a predetermined shape in this way, the partial pressure of steam in the fluidized bed 1 is adjusted by the moisture adjusting device 7 and the concentration adjusting device 9 to change the vapor pressure of chloridizing water. It is also possible to adjust the pressure to a predetermined value. In other words, if the water vapor partial pressure in the fluidized bed 1 is set sufficiently low with respect to the vapor pressure of calcium chloride, the proportion of confetti-shaped particles will increase as in the case where the spray height is increased. Conversely, when the partial pressure of water vapor in the fluidized bed 1 approaches the vapor pressure of calcium chloride, the ratio of round particles increases. Of course, like this, If the adjustment of the water vapor partial pressure and the adjustment of the spray height are performed together, the ratio of the particles of each shape becomes higher.

Further, in this embodiment, the granulated material discharged from the fluidized bed 1 is separated into coarse particles, medium particles, and fine particles by the vibrating sieve device 14, and among these, medium particles within a predetermined particle size distribution range. Only the product is subjected to anti-caking treatment by the drying cooler 16 to produce a product, and the coarse and fine particles and some medium particles pulverized by the pulverizer 15 are circulated to the fluidized bed 1 as seed particles. It has been made like that. Therefore, for example, when the amount of calcium chloride in the calcium chloride hydrate discharged as the above product and the aqueous solution of calcium chloride sprayed into the fluidized bed 1 is balanced, the seed particles from the seed hopper 12 are obtained only during the initial operation. Can be supplied to the fluidized bed 1 and, during normal operation, the seed particles can be covered by the circulating particles, so that efficient operation can be achieved.

However, when circulating the particles separated by the vibrating sieve device 14 in the fluidized bed 1 as described above, if the amount of the circulated particles is too large relative to the amount of the product particles, the product yield On the other hand, if the amount of circulating particles is too small relative to the amount of product particles, the amount of seed particles in the fluidized bed 1 will be insufficient and seed particles will be frequently replenished from the seed hopper 12. Operation becomes complicated. Therefore, the ratio of the total weight of the calcium chloride hydrate discharged from the fluidized bed 1 to the weight of the above-mentioned medium particles that are separated and formed into a product, that is, the circulation ratio of the calcium chloride hydrate is 1.5 to 1 It is desirable to set in the range of 0. In this embodiment, part of the medium particles separated by the vibrating sieve device 14 is also circulated to the fluidized bed 1, but all of the medium particles are sent to the drying cooler 16. It may be sent to the product.

Further, in the present embodiment, the vibrating sieve device 14 is particularly configured to vibrate the multi-stage sieve mesh inclined with respect to the horizontal plane by the vibrator to separate the granulated material. In this way, the size of the particles to be separated can be increased with respect to the size of the particles to be separated, and together with vibrating the sieve screen, clogging can be prevented and efficient separation can be achieved. be able to. Moreover, in the present embodiment, among the particles separated by the vibrating sieve device 14, only the medium particles, which are considered to be products, are dried and cooled. 6 and is cooled only, and the remaining pulverized coarse, fine and some medium particles are circulated uncooled to fluidized bed 1, so that the circulation of these particles It is possible to prevent the temperature in the chamber 1 from dropping greatly, and to achieve thermally and efficiently granulation of calcium chloride hydrate.

In addition to this, in the present embodiment, a part of the washing water obtained by washing the exhaust gas discharged from the fluidized bed 1 with the scrubber 17 is circulated to the tank 10 of the aqueous calcium chloride solution sprayed on the fluidized bed 1. I have to. That is, the fine particles of chloride hydrate contained in the exhaust gas are dissolved and the raw material calcium chloride is added to the washing water having a certain concentration and sprayed into the fluidized bed 1, so that the same concentration is obtained. Even if an aqueous solution of calcium chloride is sprayed, the amount of the raw material calcium chloride to be supplied to the tank 10 can be reduced, and more economical granulation of calcium chloride hydrate can be promoted. .

Next, FIG. 3 to FIG. 5 show a second embodiment of the granulating apparatus of the present invention. In the second embodiment, the basic configuration is the same as that of the first embodiment described above. Since the configuration is the same as that of the granulating apparatus of the embodiment, the same reference numerals are assigned to the same components, and the description is omitted. The second embodiment is characterized in that a means for preventing solidification of an aqueous solution of calcium chloride is provided first. That is, in the present embodiment, first, as a first solidification preventing means, the calcium chloride aqueous solution held in the tank 10 is supplied to the fluidized bed 1 through the supply pump 11 and sprayed from the spray nozzle 8. One end of a return pipe 21 is connected to the supply pipe 11 A near the fluidized bed 1 side, and the other end of the return pipe 21 is connected to the tank 10. A valve 11B is provided between the connection of the supply pipe 11A and the return pipe 21 to the spray nozzle 8 in the fluidized bed 1.

In this embodiment, one end of the drainage pipe 22 is connected to the supply pump 11 side of the supply pipe 1〗 A via a valve 22 A as a second solidification preventing means. The other end of the drainage pipe 22 is connected to the scrubber 23. In addition, a valve 11C is also provided on the fluidized bed 1 side of the supply pipe 11A slightly from the connection with the drainage pipe 22. Further, the scrubber 23 in the present embodiment is not of the bench lily type as in the first embodiment, but is an exhaust from the fluidized bed 1 introduced into the washing tower 23A. It is of a spray type in which air is washed by washing water sprayed from a spray nozzle 23B provided at an upper part in the washing tower 23A, and this exhaust gas is washed and contained in the exhaust gas. The washing liquid having absorbed the calcium chloride component is held in the washing tower 23A bottom P, heated by steam, circulated as washing water by a scrubber pump 19 as in the first embodiment, and Part of the supply is also possible to be circulated to the above-mentioned tank 0.

On the other hand, among the granulated calcium chloride hydrate generated in the fluidized bed 1, coarse particles separated by the vibrating sieve device 14 are also separated through the first damper 24 in the present embodiment. The supplied medium particles are supplied to a pulverizer 15 together with a part of the medium particles other than discharged as a product, pulverized, and further, together with fine particles, pass through a second damper 25 as seed particles to form a fluidized bed 1. It is possible to circulate. Here, as shown in FIG. 4, the first and second dampers 24 and 25 supply the separated coarse particles, coarse particles and a part of the medium particles, and fine particles. The feed pipe 26 to be fed is branched into two branches, and a shield plate 27 is swingably attached to a branch portion in the feed pipe 26. By closing one of the feed pipes 26, particles can be selectively fed to the other. In the first damper 24, the branched feed pipe 26 is connected to the mill 15 and the drying cooler 16 respectively, and is connected to the second damper 25. In other words, the branched feed pipe 26 is connected to the fluidized bed 1 and the seed hopper 12.

In the present embodiment, the medium particles separated by the vibrating sieve device 14 are supplied to a storage device 28 as shown in FIG. The storage device 28 includes a hopper 28A for storing the supplied medium particles, a vibrating conveyor 28B attached to a lower end of the hopper 28A, and a height direction of the hopper 28A. And a supply pipe 28 C connected to the crusher 15 at a middle position in the hopper 28 A, and the medium particles stored in the hopper 28 A are required by the vibrating conveyor 28 B. The medium particles collected in the hopper 28A beyond the position of the supply pipe 28C are discharged from the supply pipe 28C, It is supplied to the crusher 15 and crushed together with the coarse particles as described above. Have been.

Thus, in the granulating apparatus of the second embodiment configured as described above, the same effects as those of the first embodiment can be obtained, as well as the first and second anti-consolidation means. Since the return pipe 21 and the drain pipe 22 are provided, the aqueous solution of calcium chloride stays when the re-granulation work in which the granulation of calcium chloride hydrate is temporarily stopped is completed. This can prevent a situation where re-consolidation occurs and hinders the subsequent restart of granulation. That is, for example, when the spraying of the aqueous solution of calcium chloride from the spray nozzle 8 into the fluidized bed 1 is interrupted and the granulation is stopped, the aqueous solution of calcium chloride is left in the supply pipe 11A and stays there. If the calcium chloride solution is condensed and clogged, and then the granulation is restarted, the calcium chloride solution may not be able to be supplied to the supply pipe 1A even if the calcium chloride solution is sprayed from the spray nozzle 8. However, in such a case in the present embodiment, by closing the valve 11B, the calcium chloride aqueous solution remaining in the supply pipe 11A is returned to the tank 10 via the return pipe 21. Alternatively, the calcium chloride aqueous solution is circulated through the supply pipe 11A and the return pipe 21 so that the calcium chloride aqueous solution in the supply pipe 11A solidifies due to stagnation. It is possible to prevent.

In addition, instead of such a temporary suspension of granulation, for example, granulation of a predetermined calcium chloride hydrate is completed and the granulation operation is completed, and the granulator is stopped for a relatively long time. In some cases, the calcium chloride aqueous solution held in the tank may be solidified due to stagnation. However, in order to prevent such caking in the tank 10, steam must be continuously supplied to the tank 10 and stirring must be performed even while the granulating apparatus is stopped, so that thermal Although it is inevitable that economical efficiency is impaired both in terms of power and dynamics, in this embodiment, in such a case, the calcium chloride aqueous solution remaining in the supply pipe 11A is returned by the return pipe 21 as described above. After returning to the tank 10, the valve 11 C is closed, the valve 22 A of the drain pipe 22 is opened, and the calcium chloride aqueous solution in the tank 10 is drained to the scrubber 23, and this evening. The link 10 can be emptied to prevent consolidation. Therefore, in this case, together with the washing water in which the calcium chloride component, which is the same calcium chloride aqueous solution, is dissolved, Since the aqueous solution of calcium chloride in the tank 10 can be retained in the scrubber 23, it is sufficient to heat only the aqueous solution of calcium chloride in the scrubber 23 so as not to cause caking. However, tank 10 is more economical and efficient than preventing caking. Next, when the granulation operation is restarted, the aqueous solution of calcium chloride may be supplied from the scrubber 23 to the tank 10 by the scrubber pump 19 as described above.

Further, after the completion of the granulation work, when the work is resumed next, first, after the inside of the fluidized bed 1 is washed, the heated fluidizing gas is supplied from the hot blast stove 6 and the inside of the fluidized bed 1 is supplied. Must be dried and heated, and the calcium chloride aqueous solution must be concentrated in the tank 10 to adjust the concentration. In the present embodiment, the washing water can be circulated in the scrubber 23 as described above. In addition, since at least a part thereof can be supplied to the tank 10, the concentration time of the aqueous calcium chloride solution before the restart of the granulation operation can be shortened. That is, before restarting the granulation operation, for example, an aqueous solution of calcium chloride having a concentration of, for example, about 35 to 37 wt% is supplied and circulated into the scrubber 23, and the fluidized bed 1 is added to the scrubber 23. By introducing the high-temperature exhaust gas generated at the time of heating and drying, the chlorination aqueous solution supplied to the scrubber 23 together with the heat of the steam supplied to the scrubber 23 is quickly cooled. For example, it can be concentrated to a concentration of about 501%. Therefore, according to the present embodiment, it is possible to shorten the preparation time required for resuming the granulation work, and, for example, at the beginning of the resumption of the granulation work, the scrubber 23 does not pass through the tank 10. It is also possible to supply and spray the calcium chloride aqueous solution whose concentration has been directly adjusted to the fluidized bed 1 or, in some cases, omit the tank 10 itself. The same applies to the venturi-type scrubber 17 of the first embodiment.

Further, in the present embodiment, the scrubber 23 sprays the exhaust gas introduced into the washing tower 23A from the spray nozzle 23B instead of the venturi scrubber 17 as in the first embodiment. It is a spray type that is washed with washing water. However, such a spray-type scrubber 23 has a lower exhaust gas flow rate than the venturi-type scrubber 17. Since the pressure loss is reduced, the power of the exhaust blower 18 for discharging the exhaust gas washed from the washing tower 23A is also small, and therefore, according to the present embodiment, More economical granulation can be achieved.

By the way, when the granulation operation is completed as described above, the seed particles in the fluidized bed〗 are discharged in order to prevent solidification. The particles must be supplied into the fluidized bed 1.However, at this time, if the granulated calcium chloride hydrate was supplied from outside the system as seed particles to the seed hopper 12 and charged into the fluidized bed 1, , Inefficient and uneconomical. However, in the present embodiment, on the other hand, during the normal granulation operation, coarse particles of calcium chloride hydrate granules directly supplied to the fluidized bed 1 as seed particles and pulverized particles of medium particles And fine particles can be selectively supplied to the seed hopper 12 by switching the second damper 25. Therefore, when the granulation operation is completed as described above, the second damper 25 is switched to supply the coarse and medium particles and the fine particles to the seed hopper 12 as seed particles. By keeping the same, the next time the granulation operation is resumed, it is possible to supply the fluidized bed 1 without introducing seed particles from outside the system, and it is possible to achieve efficient granulation .

Moreover, in the present embodiment, in addition to the coarse particles, a part of the medium particles discharged from the hopper 28 A of the reservoir 28 via the supply pipe 28 C was also crushed by the crusher 15. Above, the fine particles are stored in the liquid hopper 12 circulated through the fluidized bed 1 and are used as seed particles, so that the particle diameter of the seed particles becomes larger than necessary. In other words, it is possible to prevent the ratio of granulated calcium chloride hydrate separated as coarse particles in the vibrating sieve device〗 4 from increasing, and to promote more efficient granulation. Becomes However, in such a granulator, in addition to using only medium particles having a particle size within a predetermined range as a product as in the first embodiment, in some cases, a coarse particle having a larger particle size may be used. Particles may be required as a product. However, even in such a case, in the present embodiment, the coarse particles separated in the vibrating sieve device 14 are selectively supplied to the drying cooler 16 by switching the first damper 25 described above. It has the advantage that it can be discharged as a product and can easily respond to the demands described above. are doing.

Next, Table 1 shows an example of the present invention, in which the concentration of the aqueous solution of calcium chloride sprayed into the fluidized bed 1 using the granulator of the first embodiment shown in FIG. Salting by changing the spraying rate, the spray gas temperature and the superficial velocity of the fluidizing bed supplied to the fluidized bed 1, the height of the spray nozzle 8 from the height of the fluidized bed 1 at the stationary bed, and the circulation ratio The temperature, water vapor partial pressure, and vapor pressure of calcium chloride dihydrate in the fluidized bed 1 when granulated calcium dihydrate is formed, as well as the shape of the formed particles and salinity as product This study examined how the concentration of calcium dihydrate changed. The average particle size of the produced calcium chloride hydrate particles was 275 m in Example 3, and the particle size distribution was 2 to 4 Ml.

However, from the results shown in Table 1, according to the present invention, in all of Examples 1 to 10, a 37% to 53% by weight dilute aqueous solution of calcium chloride was used to ensure the calcium chloride dihydrate. In the case where a granulated product can be granulated, and a general granulated product having a calcium chloride hydrate concentration of 8 O wt% or less as a product is produced, Examples 1 to 6 As shown, the temperature of the fluidizing gas was relatively low, up to about 150 ° C. Further, even when granulating a product calcium chloride hydrate having a high concentration as in Examples 7 to 10, the temperature of the flowing gas is raised by heating the flowing gas by the hot blast stove 6. Since it was only necessary to raise the temperature, it was extremely easy to concentrate the calcium chloride aqueous solution to the molten salt state as in the past. On the other hand, when the height of the spray nozzle 8 is changed, the height of the stationary bed is changed regardless of the concentration and spray amount of the aqueous calcium chloride solution to be sprayed, the temperature of the flowing gas, and the superficial velocity. Thus, in Examples 2 to 5 where the particle size was 27ΟΩ or less, the particles were round, and in Examples 1 and 6 to 10 where the particle size was 32 O mm or more, the particles were in the shape of confetti. However, this is not a result of the fact that all the particles are in the shape of round granules or confetti, as described above. table 1

t

Industrial applicability

As described above, according to the method for granulating calcium chloride hydrate of the present invention, since a calcium chloride hydrate is granulated using a fluidized bed, the calcium chloride hydrate is comparatively diluted with a dilute calcium chloride aqueous solution. Granules can be produced even at low temperatures, and the partial pressure of water vapor in the fluidized bed is adjusted by adjusting the amount of water in the fluidizing gas or the concentration of the aqueous calcium chloride solution sprayed. By doing so, the vapor pressure of calcium chloride hydrate in the fluidized bed is set to the vapor pressure of calcium chloride hydrate having a predetermined number of water molecules according to the temperature in the fluidized bed, and the chloride pressure of this number of water molecules is increased. It is possible to reliably granulate calcium hydrate. Further, by controlling at least the temperature in the fluidized bed and the exhaust humidity from the fluidized bed to control the partial pressure of steam in the fluidized bed, the partial pressure of steam in the fluidized bed can be accurately adjusted. As a result, calcium chloride hydrate can be more reliably produced.

On the other hand, in such a granulation method using a fluidized bed, the spray height of the aqueous solution of calcium chloride with respect to the height of the stationary bed of the fluidized bed is set to 30 Oral or more to produce particles in the shape of confetti. By adjusting the spray height, for example, by setting the spray height to less than 300 and generating round particles, a granulated product containing particles of a predetermined shape is generated. It is possible to provide granules having an appropriate shape according to the use of the product calcium chloride hydrate. Also, by adjusting the partial pressure of water vapor in the fluidized bed with respect to the vapor pressure of calcium oxide, a granulated product containing particles of a predetermined shape can be produced. Further, the granulated product of calcium chloride hydrate thus formed in the fluidized bed is separated into coarse particles, medium particles and fine particles, and the coarse particles are pulverized and desirably at least 1.5 to 10 together with the fine particles. By circulating through the fluidized bed at a circulation ratio of, it is possible to promote efficient granulation by circulating and supplying seed particles while ensuring product yield. Furthermore, in this case, it is more efficient to separate the particles by at least two inclined vibrating sieves. Also, according to the calcium chloride hydrate granulating device of the present invention, the granulation device is provided with a moisture control device by controlling based on the measurement result by a temperature sensor and a humidity sensor provided in the fluidized bed. Measurement results by the flow rate sensor, temperature sensor, and humidity sensor, and by the concentration sensor and flow rate sensor provided in the concentration adjustment device By controlling the partial pressure of water vapor in the fluidized bed by control based on the measurement results, the vapor pressure of calcium chloride in the fluidized bed is more accurately set to a predetermined vapor pressure, and the desired water is surely supplied. Calcium chloride hydrate having the number of molecules can be granulated, and the automation of the operation of the granulator can be promoted.

Furthermore, in this granulator, a return pipe returning to the tank can be connected to the supply pipe to the fluidized bed from the tank of the aqueous solution of calcium chloride, or this tank can be connected to a scrubber that processes the exhaust of the fluidized bed. To prevent the granulation in the fluidized bed from temporarily stopping, or to prevent the calcium chloride aqueous solution from accumulating in the supply pipes and tanks when the granulation operation is completed, etc. This eliminates the need to remove clogging due to consolidation the next time granulation is restarted, so that efficient and economical granulation work can be achieved. In addition, if at least a part of the granulated calcium chloride hydrate 1 generated in the fluidized bed can be selectively supplied to the seed hopper, when the operation is restarted after the end of the granulation operation as described above, There is no need to prepare calcium chloride hydrate seed particles from outside the system, which is efficient. Furthermore, if it is possible to selectively discharge at least a part of the coarse particles obtained by separating the formed granules of calcium chloride hydrate, even if such coarse particles are required as a product, it can be easily handled. Can respond.

Furthermore, in the case where a scrubber is connected to the fluidized bed, the washing water obtained by washing the exhaust gas can be circulated to the scrubber, and at least a part thereof can be supplied to the fluidized bed side. In addition to facilitating concentration adjustment in the tank during granulation work, for example, even when the calcium chloride aqueous solution is concentrated before resuming granulation work, the calcium chloride aqueous solution is concentrated in a scrubber instead of such a tank. Then, it can be supplied to the fluidized bed side, that is, the tank or directly to the fluidized bed, and it is possible to shorten the concentration time and promote efficient granulation work. If the scrubber is of a spray type, the power of the exhaust blower of the scrubber can be reduced, which is more efficient and economical.

Claims

The scope of the claims

1. A method for granulating calcium chloride hydrate, in which a calcium chloride aqueous solution is sprayed while fluidizing seed particles in a fluidized bed to form granules, wherein the partial pressure of steam in the fluidized bed is adjusted. A method for granulating calcium chloride hydrate, comprising setting the vapor pressure of calcium chloride in a fluidized bed to the vapor pressure of calcium chloride hydrate having a predetermined number of water molecules with respect to the temperature in the fluidized bed.

2. The calcium chloride water according to claim 1, wherein the partial pressure of steam in the fluidized bed is adjusted by adjusting the amount of water in the fluidizing gas supplied to the fluidized bed. Granulation method of Japanese products.

3. The calcium chloride aqueous solution according to claim 1, wherein the partial pressure of steam in the fluidized bed is adjusted by adjusting the concentration of the aqueous calcium chloride solution supplied to the fluidized bed. Granulation method of Japanese products.

4. The calcium chloride according to claim 1, wherein the partial pressure of steam in the fluidized bed is controlled by measuring at least the temperature in the fluidized bed and the exhaust humidity from the fluidized bed. Hydrate granulation method.

5. A granulated product containing particles of a predetermined shape is produced by adjusting the spray height of the aqueous solution of calcium chloride, whereby the aqueous solution of calcium chloride according to claim 1 is produced. Granulation method of Japanese products.

6. A granulated product containing particles in the shape of confetti is formed by setting the spray height with respect to the height of the stationary bed of the fluidized bed to 300 or more. Item 6. The method for granulating calcium chloride hydrate according to Item 5.

7. Set the spray height above the static bed height of the fluidized bed to less than 300 6. The method for granulating calcium chloride hydrate according to claim 5, wherein a granulated product containing round particles is produced.

8. A granulated product containing particles of a predetermined shape is produced by adjusting the partial pressure of steam in the fluidized bed with respect to the vapor pressure of calcium chloride in the fluidized bed. 2. The method for granulating calcium chloride hydrate according to item 1 above.

9. The granulated calcium chloride hydrate produced in the fluidized bed is separated into coarse particles, medium particles and fine particles, and the coarse particles are pulverized and circulated through the fluidized bed together with at least the fine particles. The method for granulating calcium chloride hydrate according to claim 1, characterized in that:

10. The ratio of the total weight of the calcium chloride hydrate discharged from the fluidized bed to the weight of the above-mentioned medium particles to be separated into products is in the range of 1.5 to 10. 10. The method for granulating calcium chloride hydrate according to claim 9.

11. The method for granulating calcium chloride hydrate according to claim 9, wherein the granulated material is fractionated by at least two inclined vibrating sieves.

12. A calcium chloride hydrate granulator for generating granules by spraying an aqueous solution of calcium chloride while fluidizing seed particles in a fluidized bed, wherein the fluidized bed includes A temperature sensor for measuring the temperature and a humidity sensor for measuring the exhaust humidity from the fluidized bed are provided, and at least the partial pressure of water vapor in the fluidized bed is controlled by control based on the measurement results of the temperature sensor and the humidity sensor. Adjusting the vapor pressure of calcium chloride in the fluidized bed to the vapor pressure of calcium chloride hydrate having a predetermined number of water molecules with respect to the temperature in the fluidized bed. Japanese granulator.

1 3. The fluidized bed contains water for adjusting the water content of the fluidizing gas supplied to the fluidized bed. And a flow rate sensor for measuring the amount of water applied to the flow gas, and a temperature for measuring the temperature and humidity of the flow-adjusted flow gas. A sensor and a humidity sensor, and at least the flow rate is controlled by the control based on the measurement results of the flow rate sensor, the temperature sensor, and the humidity sensor and the measurement results of the temperature sensor and the humidity sensor provided in the fluidized bed. by adjusting the water content of the gas, granulator calcium chloride hydrate according to the first two terms claims, characterized by adjusting the water vapor partial pressure of the fluidized bed ₍

14. The fluidized bed is provided with a concentration adjusting device for adjusting the concentration of the aqueous calcium chloride solution supplied to the fluidized bed, and the concentration adjusting device is provided with a concentration of the adjusted aqueous solution of calcium chloride. And a flow rate sensor for measuring the flow rate and the flow rate.A control based on at least the measurement results of the concentration sensor and the flow rate sensor and the measurement results of the temperature sensor and the humidity sensor provided in the fluidized bed. 13. The apparatus for granulating calcium hydrate according to claim 12, wherein the partial pressure of steam in the fluidized bed is adjusted by adjusting the concentration of the aqueous solution of calcium chloride.

15. The calcium chloride aqueous solution is supplied from the tank to the fluidized bed via a supply pipe and is sprayed, and the supply pipe has a return pipe for returning the calcium chloride aqueous solution in the supply pipe to the tank. The granulator for calcium chloride hydrate according to claim 12, wherein the granulator can be connected.

16. The calcium chloride aqueous solution is supplied from the tank to the fluidized bed and sprayed, and the tank can be connected to a scrubber for washing exhaust gas discharged from the fluidized bed with washing water. 13. The granulator of calcium chloride hydrate according to claim 12, wherein the aqueous solution of calcium chloride in the tank is supplied to the scrubber and can be held.

17. A seed hopper that supplies the seed particles to the fluidized bed is connected to the fluidized bed. And at least a part of the calcium chloride hydrate granules generated in the fluidized bed can be selectively supplied to the seed hopper. Item 12. A granulator for granulation of calcium chloride hydrate according to Item 2.

18. The above-mentioned fluidized bed is connected to a vibrating sieve device for separating the granulated calcium chloride hydrate produced in the fluidized bed into coarse particles, medium particles and fine particles. The granulated calcium chloride hydrate according to claim 12, wherein at least a part of the coarse particles can be selectively discharged as a product granulated product.

19. A scrubber for washing the exhaust gas discharged from the fluidized bed with washing water is connected to the fluidized bed, and the washing water for washing the exhaust gas can be circulated to the scrubber. 13. The granulation device of calcium chloride hydrate according to claim 12, wherein at least a part thereof can be supplied to the fluidized bed side.

20. A scrubber for washing the exhaust gas discharged from the fluidized bed with washing water is connected to the fluidized bed, and the scrubber introduces the exhaust gas into the washing tower and is sprayed into the washing tower. 3. The granulation device for calcium chloride hydrate according to claim 12, wherein the granulation device is a spray-type scrubber for washing with the washing water.