Method for estimating the absolute dry bulk density of a composition containing a volatile liquid and method for forming a composition containing a volatile liquid

Abstract

To provide a method for estimating the absolute dry bulk density of a composition containing a volatile liquid.SOLUTION: A composition containing a volatile liquid is irradiated with electromagnetic waves to volatilize the volatile liquid. Based on the mass of the composition after the electromagnetic wave irradiation and the volume of the composition before or after the electromagnetic wave irradiation, the density is determined. The density is estimated as the absolute dry bulk density of the composition. This method is characterized by pre-setting the irradiation time such that the mass of the composition containing the volatile liquid becomes constant. This method is also characterized by using a lightweight composition, wherein the absolute dry bulk density of the composition containing the volatile liquid is less than 2.0 g / cm3.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for estimating the oven-dry bulk density of a composition containing a volatile liquid. In particular, it relates to a method for estimating the oven-dry bulk density of lightweight compositions containing a volatile liquid, such as a fiber composition consisting of fibers and a binder slurry, or lightweight mortar.

[0002] Furthermore, the present invention relates to a method for forming a composition containing a volatile liquid. In particular, the present invention relates to a method for forming a lightweight composition containing a volatile liquid, such as a fibrous composition consisting of fibers and a binder slurry, or a lightweight mortar. [Background technology]

[0003] For the purpose of providing fire resistance, fire prevention, sound absorption, and / or heat insulation, it has been proposed to provide a layer on the surface of structures and articles, or inside walls, ceilings, and / or floors, consisting of a binder containing water and / or volatile organic compounds, and a mixture of fibers such as rock wool or lightweight aggregates, i.e., a composition containing volatile liquids. Typical examples of compositions containing volatile liquids include a rock wool composition consisting of a mixture of cement slurry (a mixture of cement and water) and rock wool, or lightweight mortar containing cement, water, ordinary aggregates, and lightweight aggregates.

[0004] Lightweight compositions containing volatile liquids such as rock wool compositions and lightweight mortar exhibit properties such as fire resistance, fire prevention, sound absorption, or heat insulation when the appropriate oven-dry bulk density is achieved. Therefore, it is important to measure and confirm the oven-dry bulk density (and in some cases, oven-dry specific gravity) of the composition (for example, Non-Patent Document 1 and Patent Document 1 (paragraph)).

[0005] ))

[0005] In conventional techniques, the collected sample is placed in a dryer, heated until a constant weight is reached, and the oven-dry bulk density is measured. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-031022 [Non-patent literature]

[0007] [Non-Patent Document 1] Japan Public Building Association (ed.), "Guidelines for Construction Supervision, 2019 Edition (Volume 1)," 1st printing, Japan Public Building Association, October 25, 2019, p. 641. [Overview of the project] [Problems that the invention aims to solve]

[0008] However, it is difficult to bring a drying machine to the construction site, and it takes a long time to obtain measurement results. Therefore, it was difficult to confirm that the oven-dry bulk density of the lightweight composition was within the specified range before or during construction before forming the lightweight composition. If it is found that the oven-dry bulk density of the composition formed after construction is outside the specified range, the construction area must be removed and re-constructed, or additional construction must be carried out, which is extremely uneconomical.

[0009] The present invention aims to provide a method for estimating the oven-dry bulk density of a composition containing a volatile liquid. In particular, it aims to provide a method for estimating the bulk density quickly and accurately, both before and during construction.

[0010] Furthermore, the present invention aims to provide a method for forming a composition containing a volatile liquid, which can be obtained by obtaining a composition containing a volatile liquid having an oven-dry bulk density within a predetermined range. In particular, an oven-dry bulk density of 2.0 g / cm³ is desired. 3 The objective is to provide a method for forming a lightweight composition with a weight of less than [amount missing]. [Means for solving the problem]

[0011] The inventor of the present invention has discovered that volatile liquids can be vaporized in a short time by electromagnetic wave irradiation using a microwave oven or the like, and that the estimated oven-dry bulk density is of the same accuracy as the oven-dry bulk density obtained using the prior art, thereby completing the present invention.

[0012] The present invention for solving the above problems is a method for estimating the absolute dry bulk density of a composition containing a volatile liquid. The composition containing the volatile liquid is irradiated with electromagnetic waves to volatilize the volatile liquid, and the density is determined based on the mass of the composition after the electromagnetic wave irradiation and the volume of the composition before or after the electromagnetic wave irradiation, and the density is estimated as the absolute dry bulk density of the composition.

[0013] By electromagnetic wave irradiation, the volatile liquid can be volatilized in a short time, and the absolute dry bulk density can be estimated in a short time. On the other hand, the accuracy of the estimated absolute dry bulk density is ensured. As a result, the present invention can be applied before or during construction.

[0014] In the above invention, preferably, an irradiation time when the mass of the composition containing the volatile liquid becomes a constant amount is set in advance, and the set irradiation time is irradiated with electromagnetic waves to volatilize the volatile liquid.

[0015] By setting the irradiation time in advance in the preliminary test, it surely becomes a constant amount in the test construction. Thereby, the test construction can be performed in a short time.

[0016] In the above invention, preferably, the electromagnetic wave is a microwave.

[0017] By microwave irradiation, the volatile liquid can be volatilized in a short time.

[0018] In the above invention, preferably, the absolute dry bulk density of the composition containing the volatile liquid is less than 2.0 g / cm 3 and it is a lightweight composition.

[0019] When the absolute dry bulk density is less than 2.0 g / cm 3 and it is a lightweight composition, the volatile liquid can be volatilized in a short time by electromagnetic wave irradiation.

[0020] The present invention for solving the above problems is a method for forming a composition containing a volatile liquid. In a test application, a composition containing a volatile liquid is formed, and the dry bulk density of the composition is estimated by the above method. It is confirmed that the specified dry bulk density is within a predetermined range. When the estimated dry bulk density is within the predetermined range, in this application, a composition containing a volatile liquid is formed under the same application conditions as those in the test application.

[0021] Thereby, a layer such as a coating layer or a filling layer having predetermined performance can be formed.

[0022] In the above invention, preferably, the test application is carried out as a part of this application.

[0023] Thereby, the present invention can be applied not only before application but also during application.

Effect of the Invention

[0024] According to the present invention, the dry bulk density of a composition containing a volatile liquid can be estimated. In particular, it can be estimated accurately in a short time before and during application.

[0025] According to the present invention, a composition containing a volatile liquid having a dry bulk density within a predetermined range can be formed. In particular, a composition having a dry bulk density of less than 2.0 g / cm 3 can be formed.

[0026] As a result, a layer made of the composition having predetermined fire resistance, fireproofness, sound absorption, and / or heat insulation can be formed. The layer coats the surface of a structure or an article, fills the inside, or forms a structure or an article. Examples of the article here include, for example, a fireproof safe, building materials such as siding boards and floor materials, a soundproof booth, a WEB conference booth, a cold storage, and the like.

Brief Description of the Drawings

[0027] [Figure 1] Example of the apparatus of the spraying system used in this application [Modes for carrying out the invention]

[0028] ~Composition, etc.~ In the present invention, an electromagnetic wave is irradiated onto a composition containing a volatile liquid (hereinafter, as may be referred to as a volatile liquid-containing composition) to cause the volatile liquid to volatilize, the density is determined, and the density is estimated as the absolute dry bulk density of the composition. Each of the above components will be described in detail.

[0029] The oven-dry bulk density is defined in the prior art. The sample is placed in a drying oven and heated until a constant weight is reached. The oven-dry bulk density ρ is determined based on the mass and volume of the composition after drying.

[0030] In this invention, the density ρ1 is determined based on the mass M1 and volume V1 of the composition after electromagnetic wave irradiation. Specifically, it is determined by equation (1). The oven-dry bulk density ρ based on the prior art and the estimated bulk density ρ1 of this invention are considered to be approximately equal (verified below). Therefore, the estimated bulk density ρ1 of this invention is estimated to be the oven-dry bulk density ρ. ρ1 = M1 / V1··· (1)

[0031] In this invention, it has been confirmed that the change between the volume V0 of the volatile liquid-containing composition before electromagnetic wave irradiation and the volume V1 of the volatile liquid-containing composition after electromagnetic wave irradiation is small. The bulk density ρ1 of the volatile liquid-containing composition after electromagnetic wave irradiation may be calculated by using V0 instead of V1 in formula (1) as appropriate. In particular, the change between V0 and V1 is smaller when the volatile liquid-containing composition is a lightweight composition, and the smaller the oven-dry bulk density ρ of the volatile liquid-containing composition, the smaller the change. The oven-dry bulk density ρ of the volatile liquid-containing composition is 1.0 g / cm³. 3 In the following cases, there is almost no such change.

[0032] In the volatile liquid-containing composition of the present invention, water is a typical example of the volatile liquid, but organic compounds that are liquid at room temperature and volatile, such as ethanol, butanol, and ethyl acetate, can also be used. Preferably, it is water or an aqueous solution. The water referred to here includes water as a dispersion medium.

[0033] Regarding the composition containing a volatile liquid in the present invention, that is, the volatile liquid-containing composition, in addition to the volatile liquid, it preferably contains one or more selected from latent hydraulic substances such as cement, alkali silicate, blast furnace slag powder, pozzolans such as silica fume and fly ash, organic binders composed of polymers such as vinyl acetate resins, acrylic resins, and synthetic rubbers, inorganic fibers such as rock wool and ceramic wool, organic fibers such as nylon fibers and vinylon fibers, lightweight aggregates such as perlite and organic lightweight aggregates, normal aggregates such as silica sand and crushed sand, and one or more other admixtures.

[0034] Particularly, it contains one or more selected from cement, alkali silicate, latent hydraulic substances, pozzolans, and organic binders, one or more selected from inorganic fibers, organic fibers, lightweight aggregates, foaming agents, and blowing agents, and a volatile liquid such as water, and has a dry bulk density of less than 2.0 g / cm 3 Less is preferred for the lightweight composition. When the dry bulk density is less than 2.0 g / cm 3 Less, the volatile liquid inside is likely to be discharged to the outside of the lightweight composition. That is, the volatile liquid is likely to volatilize and volatilizes in a short time.

[0035] Regarding the volatile liquid-containing composition used in the present invention, since the volatile liquid is likely to volatilize by electromagnetic waves, a lightweight composition with a dry bulk density of less than 2.0 g / cm 3 Less is preferred, a lightweight composition with a dry bulk density of less than 1.5 g / cm 3 Less is more preferred, and a lightweight composition with a dry bulk density of less than 1.0 g / cm 3 Less is even more preferred.

[0036] ~Operation~ The method for irradiating with electromagnetic waves in this invention can be any method using a device that can volatilize the volatile liquid contained in a volatile liquid-containing composition by irradiating it with electromagnetic waves. However, the method using a microwave oven is preferred because the device is inexpensive and readily available, and the method can be easily carried out at the construction site. A sample of the volatile liquid-containing composition is placed inside the oven of a microwave oven, the microwave oven is switched on, and electromagnetic waves are irradiated into the oven.

[0037] In this invention, the electromagnetic waves irradiated should have a frequency and intensity capable of volatilizing the volatile liquid. In this invention, infrared rays or microwaves are preferred because they easily volatilize the volatile liquid, and microwaves are particularly preferred because they can volatilize the volatile liquid in a short time when the volatile liquid is water or an aqueous solution. Since microwave ovens generate microwaves at 2.45 GHz and irradiate the contents inside the oven, using a microwave oven as the method for irradiating with electromagnetic waves in this invention is more preferred.

[0038] In this invention, the irradiation time of electromagnetic waves is the time it takes for the mass of the volatile liquid-containing composition irradiated with electromagnetic waves to become constant, and it is preferable to set this time through preliminary testing. In the test application, the composition is irradiated with electromagnetic waves for the set irradiation time to volatilize the volatile liquid. This ensures that the mass becomes constant and guarantees accuracy (verification below).

[0039] Furthermore, in this invention, the irradiation time of electromagnetic waves should be within a range where the compounds contained in the volatile liquid-containing composition do not decompose due to prolonged irradiation with electromagnetic waves. For this reason, it is preferable to confirm through preliminary tests that the electromagnetic waves do not decompose the compounds contained in the volatile liquid-containing composition and then set the irradiation time accordingly.

[0040] By setting the irradiation time through preliminary testing, the test construction can be carried out in a shorter time and with less hassle.

[0041] If preliminary tests are not conducted, the duration of electromagnetic wave irradiation is determined during the test construction by measuring the mass of the volatile liquid-containing composition after irradiation while increasing the irradiation time, and ending the electromagnetic wave irradiation when a constant weight is reached.

[0042] In test construction, suitable methods for collecting samples of the volatile liquid-containing composition irradiated with electromagnetic waves include, but are not limited to, methods such as cutting off a sample after forming the volatile liquid-containing composition on a substrate such as a board or block, or methods of filling a container of a predetermined volume with the sample.

[0043] In this invention, the estimated oven-dry bulk density obtained during the test construction is confirmed to be within a predetermined range. If the estimated oven-dry bulk density is within the predetermined range, the composition containing the volatile liquid is formed in the main construction under the same construction conditions as in the test construction. If the estimated oven-dry bulk density is outside the predetermined range, the main construction is interrupted, the cause of the problem is investigated, and adjustments are made to obtain an oven-dry bulk density within the predetermined range.

[0044] Here, the specified range refers to the range that satisfies the management standards, and is the range of oven-dry bulk density set to satisfy the required performance such as fire resistance, fire prevention, sound absorption, and heat insulation of the layer made of the volatile liquid-containing composition formed in this construction.

[0045] In this invention, the same construction conditions for the test construction and the actual construction mean that, when using machinery such as pumps, blowers, or cotton wicking machines to form the volatile liquid-containing composition, the settings of these machines are kept the same when forming the volatile liquid-containing composition, and when using manual methods such as trowel application, the work is carried out to be as similar as possible when forming the volatile liquid-containing composition. Furthermore, the same types and proportions of materials constituting the volatile liquid-containing composition are also included in the definition of the same construction conditions.

[0046] In this invention, the test construction may be carried out the day before (or earlier than) the main construction, or immediately before the main construction on the day of the main construction. The test construction may be carried out at the main construction site or at a different site.

[0047] In this invention, the estimation of the oven-dry bulk density can be performed in a short time, so even if it is done immediately before the actual construction, it will not affect the construction process. Test construction performed immediately before the actual construction does not require the preparation of separate equipment or personnel, and costs can be kept to a minimum.

[0048] Furthermore, the test construction may be carried out as part of the main construction. Specifically, the composition is formed during the main construction, and a portion of the formed composition is taken as a sample, the oven-dry bulk density is estimated, and it is confirmed that it is within a predetermined range.

[0049] Test construction as part of the main construction should be carried out in the first half of the main construction, preferably at the beginning of the main construction, and more preferably immediately after the start of the main construction. It may also be carried out at predetermined intervals or at predetermined time intervals.

[0050] This allows for verification that the construction is being carried out properly during the actual construction process, significantly reducing the psychological burden on the workers.

[0051] ~Example of construction equipment~ Figure 1 shows an example of a spraying system used in this construction. The system configuration and operation will be explained using a semi-dry spraying method for rock wool as an example. The process is similar even when a semi-dry spraying method using a slurry mixed with water, sodium silicate aqueous solution, and blast furnace slag powder is used instead of cement slurry in the rock wool semi-dry spraying method.

[0052] The spraying device 10 comprises a cotton pulping machine 20, a blower 14, a fiber pumping hose 9, a liquid additive pumping pump 7, a liquid additive pumping hose 6, and a granular fiber spraying nozzle 1.

[0053] The cotton pulping machine 20 includes a first cotton pulping section 21, a second cotton pulping section 22, a hopper 23, a screw feeder 24, a rotary feeder (quantitative feeding device) 25, and a fiber pressure pipe 26.

[0054] A pack of fibers (rock wool granular cotton) is opened and fed into the hopper 23. The fibers are supplied to the inside while being unfrayed by the first unfraying section 21, transported by the screw feeder 24, granulated by the second unfraying section 22, and a predetermined amount of fibers is supplied to the fiber conveying pipe 26 by the rotary feeder 25 based on an external supply amount command. The fiber conveying pipe 26 is interposed between the blower 14 and the fiber conveying hose 9.

[0055] The fibers supplied to the fiber pumping pipe 26 are pumped through the hose by the blower 14, transported to the granular fiber spraying nozzle 1, and discharged from the discharge port. The blower 14 can be set to a predetermined air velocity based on an external air velocity command.

[0056] The granular fiber spray nozzle 1 has a spray nozzle 3 for liquid additives near the center of the discharge port (near the central axis of the spray nozzle).

[0057] Liquid additives are stored in the liquid additive storage tank 8. If the liquid additive is in slurry form, such as cement slurry, it is mixed with a dispersion medium (e.g., water) and a dispersion phase (e.g., cement), and a stirring device may be installed in the liquid additive storage tank 8 for stirring. The liquid additive (e.g., cement slurry) is pumped through the liquid additive pumping hose 6 by the liquid additive pumping pump 7 and sprayed from the nozzle 3.

[0058] The granular fibers discharged from the granular fiber spraying nozzle 1 and the cement slurry sprayed from the nozzle 3 for liquid additives merge and mix at the tip of the granular fiber spraying nozzle 1, then coat the surface of the object to be coated, forming a fibrous layer made of the merged mixture.

[0059] Even if the contractor sets the construction conditions based on their experience and carries out the work, if the oven-dry bulk density of the formed fiber layer falls outside the specified range, the same area must be reworked. If the oven-dry bulk density is less than specified, an additional fiber layer must be sprayed onto the same area and then pressed in with a trowel to bring the oven-dry bulk density within the specified range. If the oven-dry bulk density is greater than specified, the formed fiber layer must be removed and the same area reworked. This extends the construction period and incurs extra costs, placing a heavy psychological burden on the contractor.

[0060] ~Verification~ The present invention was verified through the following examples and reference examples. However, the present invention is not limited in any way to these examples.

[0061] [Sample preparation] Two types of slurries containing water (Slurry 1 and Slurry 2) were prepared. Note that the intention was to demonstrate multiple application examples, and no comparison was made based on the differences between the slurry types. • Slurry 1 A slurry (solid content 15.5% by mass) obtained by mixing water, an aqueous sodium silicate solution, and blast furnace slag powder. · Slurry 2 A slurry made by mixing water and cement (water-cement ratio of 200%). Each prepared slurry was mixed with rock wool to create a rock wool composition containing a volatile liquid (volatile liquid-containing composition). The mixing ratio of each slurry to the rock wool was as follows by mass ratio. Slurry 1: Rockwool = 3:2 Slurry 2: Rockwool = 3:1.5

[0062] [Sample collection] Rock wool compositions were prepared using two different methods, and samples were obtained by cutting them into cylindrical shapes with a diameter of 8 cm using a bulk density measuring cutter. • Samples prepared by filling (indicated as "filled") The prepared rock wool composition was filled into a 20 x 20 x 5 cm mold. • Samples obtained by spraying (indicated as: spraying) A predetermined amount of each slurry and rock wool was sprayed from a spray nozzle, where they merged and mixed at the nozzle tip to form a rock wool composition which was then sprayed onto a plywood board.

[0063] [Absolutely dry bulk density] In the conventional technology, the oven-dry bulk density ρ of a rock wool composition is the bulk density when the mass becomes constant after heating in a dryer at an internal temperature of 105°C. In contrast, after measuring the thickness of the collected rock wool composition sample, the density ρ1 (estimated oven-dry bulk density) was determined by electromagnetic wave irradiation heating and drying oven heating (similar to the prior art). At this time, the volume V1 of the sample made of the rock wool composition after drying is equal to the volume V0 of the sample before drying, which is determined from the thickness of the sample before drying, so the mass M1 after drying and the volume V0 before drying were used. • Heating by microwave irradiation inside a microwave oven (indicated as: microwave) A sample of the collected rock wool composition was placed in a microwave oven with a rated high frequency of 600W, the lid was closed, and the sample was heated by irradiating it with microwaves for the time shown in Table 1. • Heating by dryer (indicated as: dryer) The collected rock wool composition samples were placed in a dryer with an internal temperature of 105°C, the lid was closed, and the samples were heated for the times shown in Table 1.

[0064] [Heating time] A preliminary test was conducted to determine the heating time (irradiation time) at which the sample would reach a constant weight through microwave irradiation in a microwave oven. Here, constant weight is defined as the point at which the mass of the sample remained unchanged even after an additional 2 minutes of heating using a digital scale with a minimum display of 0.1 g; in other words, the mass loss of the sample was less than 0.1 g, and the mass change rate at that time was less than 0.23 mass%. The sample thickness was 4.0-5.0 cm and the oven-dry bulk density ρ of the rock wool composition was 0.19 g / cm³. 3 If the temperature is below 0.20-0.31 (g / cm³), the oven-dry bulk density ρ of the rock wool composition should be 0.20-0.31 (g / cm³). 3 If the temperature is within 7 minutes, a constant weight will be reached. Furthermore, the compounds contained in the rock wool composition will not decompose during these heating (irradiation) times.

[0065] [Table 1]

[0066] [Consideration] In both samples No. 1-4 (filled) and samples No. 5-7 (sprayed), the estimated oven-dry bulk density ρ1 and the oven-dry bulk density ρ (conventional technology) were approximately equal, confirming that sufficient estimation accuracy can be obtained. Furthermore, it was verified that the estimation accuracy was not affected by differences in sample preparation methods (filling / spraying). Note that the sample thickness differed depending on the sample preparation method (filling / spraying).

[0067] Samples No. 8 and No. 9 are for reference only. Compare them with Example Sample No. 4, which has similar conditions.

[0068] The heating time for sample No. 4 was 7 minutes, while the heating time for sample No. 9 was 180 minutes. The estimation method of the present invention ensures the same level of accuracy as the conventional technique in a short amount of time.

[0069] The heating time for sample No. 8 is set to 7 minutes, the same as for sample No. 4. In sample No. 8, the estimated oven-dry bulk density ρ1 and the oven-dry bulk density ρ (conventional technology) differ significantly, and sufficient accuracy cannot be obtained in the short time frame described in the present invention. [Explanation of symbols]

[0070] 1. Granular fiber spray nozzle 2. Pressure gauge 3. Spray nozzle for liquid additive 4. Liquid additive 5. Granular fibers (rock wool granular cotton) 6. Hose for pumping liquid additives 7. Pressure pump for liquid additives 8. Storage tank for liquid additives 9. Fiber pumping hose 10. Spraying system 11 Fibers (rock wool granular cotton) 12 Fiber layer consisting of a combined mixture 13. Object to be covered 14. Blower (air blower) 20 Cotton opening machine 21 First cotton opening section 22 Second cotton-dissolving section 23 Hopper 24 Screw feeder 25 Rotary feeder (quantitative feeding device) 26 Fiber Conveying Pipe

Claims

1. Before or during construction at the construction site, a microwave oven is used at the construction site to irradiate a composition containing a volatile liquid with microwaves to volatilize the volatile liquid. The density is determined based on the mass of the composition after microwave irradiation and the volume of the composition before or after microwave irradiation. The density is estimated as the absolute dry bulk density of the composition. A method for estimating the oven-dry bulk density of a composition containing a volatile liquid at a construction site before or during construction.

2. The irradiation time is predetermined so that the mass of the composition containing the volatile liquid becomes constant. For the set irradiation time, microwaves are irradiated onto the composition to volatilize the volatile liquid. A method for estimating the oven-dry bulk density of a composition containing the volatile liquid of claim 1 before or during construction at a construction site.

3. The absolute dry bulk density of the composition containing the volatile liquid is 2.0 g / cm³. ３ It is a lightweight composition of less than [amount missing]. A method for estimating the oven-dry bulk density of a composition containing the volatile liquid of claim 1 before or during construction at a construction site.

4. In the test construction, a composition containing a volatile liquid is formed, and the oven-dry bulk density of the composition is estimated by the method of claim 1. Confirm that the estimated absolute dry bulk density is within a predetermined range, and if the estimated absolute dry bulk density is within a predetermined range, In this construction, a composition containing a volatile liquid is formed under the same construction conditions as in the aforementioned test construction. A method for forming a composition containing a volatile liquid.

5. The aforementioned test construction will be carried out as part of the main construction. A method for forming a composition containing the volatile liquid of claim 4.

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