JPS6213480A - Method of granulating heat storing material - Google Patents

Abstract

PURPOSE:To simply granulate a latent heat storing material without sacrificing its heat storing capacity, by dropping a latent heat storing material in a molten state into an org. liq. which is neither reactive nor miscible therewith as well as has a specific gravity smaller than it. CONSTITUTION:A latent heat storing material such as calcium chloride hexahydrate or sodium acetate trihydrate is heated to allow it to melt. The latent heat storing material in a molten state is dropped into an org. liq. which is neither reactive nor miscible therewith as well as has a specific gravity smaller than it, thereby granulating the latent heat storing material. A preferable org. liq. is a liq. of which the specific gravity is by about 0.01-0.1 smaller than that of the latent heat storing material and includes an org. liq. having a desired pH value and obtd. by incorporating a specific gravity modifier such as n-octane or toluene in a halogenated hydrocarbon having a specific gravity of 1.3 or more (e.g.: carbon tetrachloride or chloroform).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for granulating a heat storage material. For more details,
This invention relates to a method for granulating latent heat type heat storage materials such as inorganic hydrates.

[Conventional technology]

Latent heat type heat storage materials, which absorb and release latent heat through melting and solidification, can be granulated to improve transportability and handling workability of the heat storage material. It is important to granulate the encapsulating material in advance in order to prevent stress concentration from occurring in the capsule during volume changes such as melting and solidification in heat storage material capsules manufactured using C. be.

However, in the case of inorganic hydrates, which are most commonly used as latent heat storage materials, for the following reasons,
Commonly used granulation methods cannot be applied.

(1) Since inorganic hydrates must have an inorganic component and a crystal water component combined in an appropriate ratio, excessive humidification and heating (dehydration) steps cannot be provided.

(2) Binder etc. are often used during granulation,
If a binder or the like is used, the ability as a heat storage material, such as the amount of latent heat, the melting temperature, the reproducibility of solidification, etc. will be significantly reduced, so these cannot be used.

(3) Inorganic hydrates generally have a low melting temperature of 100°C or less and are easily melted by heating, so temperature control is essential when attempting to granulate them in a solid state.

Therefore, even if we try to apply conventionally commonly used granulation methods to inorganic hydrates, etc.1, for example, in the transfer method and compression molding method, water etc. are added as a binder, so the reasons (1) and (2) mentioned above cannot be met. Therefore, in the sintering method, the above reason (1)
, (3), and the fluidized drying method and spray drying method cannot be applied due to the above reason (1).

[Problem that the invention seeks to solve]

As a result, the granulation method that can be applied to inorganic hydrates is limited to the submerged injection method, but after conducting various studies on the cooling liquid used in that case, we found that it is possible to It has now been discovered that granulation of inorganic hydrates, etc. can be carried out smoothly by using this as a cooling liquid.

[Means for Solving the Problem] and [Operation] Therefore, the present invention relates to a method for granulating a heat storage material, and the granulation of the heat storage material includes the following steps:
This is carried out by dropping the latent heat type heat storage material in a molten state into an organic liquid that does not react with or mix with the material and has a specific gravity smaller than that of the latent heat storage material to form a single particle. ``As the latent heat type heat storage material, inorganic hydrates such as those exemplified below are generally used.

”u1yoIL] uL member Reishin Star 1 CaCQ, fist 6H, 029℃ 1.5
ONa2Go3・IQH□0 32℃ 1.
35Na2So,・LQH,Q 1
．． 3ONa, HPO4” 12820 36℃
1.42Zn (No3), ・6H201,80 Ca (NO-)z ・4H2045℃ 1.72
Na, S, 0.・5H, 048℃ 1.65C1
l, COONa・3H, Osa℃ 1.32
These inorganic hydrates can be used by adding a nucleating agent to prevent supercooling and/or a thickening agent to prevent phase separation. When heated and melted, it becomes an aqueous solution of the inorganic salt, so the liquid that cools the molten inorganic hydrate does not react with or mix (dissolve) with it.

Moreover, about 0. It is limited to an organic liquid with a low specific gravity of about 1 to 0.1 O, which is liquid at the temperature at which the inorganic hydrate solidifies, and does not boil at the heating melting temperature.

The first component of such an organic liquid is a halogenated hydrocarbon having a specific gravity of 1.30 or more, such as carbon tetrachloride, chloroform, dichloromethane, etc., and n-hebutane,
A mixture containing an aliphatic saturated hydrocarbon such as n-octane or isooctane or an aromatic hydrocarbon such as toluene or xylene as a second component for adjusting the specific gravity is generally used. Such a mixture may be a homogeneous mixture of these two components, or may be a partial mixture, that is, a middle layer portion of the three layers of the second component/mixture of both components/second component. .

The granulation of the latent heat type heat storage material in the molten state is carried out by dropping it into an organic liquid contained in a glass column or the like by any means.In other words, the dropped melt groove falls through the organic liquid in the column. During this process, it solidifies and is deposited as particulate matter with a particle size of about 0.5 to 5 LI111 depending on the discharge amount, etc., in the organic liquid part with the same specific gravity or at the bottom of the column.

In addition, if the melt grooves coalesce together for some reason while the melt grooves are falling, and therefore granules with the desired particle size cannot be obtained, 1. Following the previous application (Japanese Patent Application No. 60-34220) related to the manufacturing method, a trace amount of water-soluble monomer, such as ethylenediamine, was added to the heat storage material melt, and one organic liquid contained By adding a small amount of oil-soluble monomer 1, such as both sebacyl chloride and trimesic acid trichloride, to form a thin interfacial polymer film of polyamide or the like at the interface of the melt groove, the melt can be Combination of grooves can be effectively prevented.

〔Effect of the invention〕

According to the method of the present invention, particles of a desired particle size can be produced very easily and continuously from the latent heat type heat storage material without any loss of its inherent heat storage ability.

〔Example〕

Next, the present invention will be explained with reference to examples.

Example 1 416 g of special grade carbon tetrachloride (specific gravity 1.63) and 169 g of special grade toluene (specific gravity 0.87) were mixed to give a specific gravity of 1.
．． An organic liquid consisting of a mixture of No. 30 was prepared, placed in a glass column with an inner diameter of 30 mm and a length of 1200 mm, and left at room temperature.

To 200 g of special grade sodium acetate trihydrate, 5 g of special grade trisodium phosphate dodecahydrate was added as a nucleating agent,
The prepared heat storage material was heated to 75°C and melted. When this heat storage material molten liquid is dropped into the organic liquid in the glass column using a syringe with a capacity of 10+mQ, the melt droplets slowly fall into the organic liquid and solidify in the middle of the column, forming a diameter of about 2 mm. It became white particles and was deposited on the bottom of the column.

Example 2 400 g of carbon tetrachloride was put into the glass column of Example 1,
When 200 g of toluene is gently poured onto it, an interface is created between carbon tetrachloride and toluene due to the difference in specific gravity. When this interface is stirred at room temperature, the interface becomes unclear and a mixture layer with a gentle density gradient is formed between the carbon tetrachloride layer at the bottom of the column and the toluene layer at the top.

When the melted heat storage material of Example 1 is dropped from a syringe into the organic liquid in the glass column in such a state, the melt droplet falls through the column, but a portion of the organic liquid whose specific gravity matches that of the droplet falls. It stops falling and solidifies here. The solidified heat storage material particles gradually increase their specific gravity and begin to fall again, and stop falling again at the organic liquid portion where the specific gravity matches, yielding granules with a particle size of approximately 3+s+s. Note that by using such an organic liquid, it is also possible to separate solidified particulate matter from unsolidified droplets.

Procedural amendment (voluntary) August 29, 1985

Claims (1)

[Scope of Claims] 1. Granulation of a heat storage material characterized by dropping a latent heat type heat storage material in a molten state into an organic liquid that does not react with or mix with the material and has a smaller specific gravity than the latent heat storage material and granulates it. Method. 2. The method for granulating a heat storage material according to claim 1, wherein the latent heat type heat storage material is an inorganic hydrate. 3. The method for granulating a heat storage material according to claim 1, wherein the organic liquid is a liquid having a specific gravity that is about 0.01 to 0.1 smaller than that of the molten heat storage material. 4. The heat storage material according to claim 1 or 3, wherein the organic liquid is a homogeneous or partial mixture of a halogenated hydrocarbon with a specific gravity of 1.30 or more and an aliphatic saturated hydrocarbon or an aromatic hydrocarbon. granulation method.