Efficient fluorescent drying agent and preparation method thereof

Abstract

The invention belongs to the field of drying agents, and particularly relates to a drying agent related to leakage detection of an air conditioner or other refrigerating systems. According to the fluorescent drying agent and the drying agent module or the drying bag, the drying agent particles and the drying agent module or the drying bag have the conventional drying function and carry fluorescent dye at the same time, and the function of fluorescent leak detection of a refrigerating system is achieved synchronously. The preparation method comprises the following steps that the formed refrigeration drying agent particles are selected, the refrigeration agent particles and the fluorescent agent powder are carried and loaded in a solid-liquid dipping or solid-solid mixing mode, and the loading amount of the fluorescent dye is comprehensively determined according to the requirement of a refrigeration system and the weight of the drying agent particles. According to the novel drying agent particle with the fluorescence detection function and the drying agent module or the drying bag, the fluorescent dye can be directly subjected to dye loading treatment on a drying agent production line, the fluorescent dye is introduced into an air conditioner refrigeration system while the drying agent container is filled, and the labor cost of the production line of an air conditioner refrigeration manufacturer is saved.

Description

Technical Field

[0001] The invention belongs to the field of desiccants, and in particular relates to desiccants related to leakage detection in air conditioners or other refrigeration systems. Background Art

[0002] Most cars now use the new R-134a refrigerant. This system is more compact than the previous R-12 system, and the amount of refrigerant is relatively small, so the leakage of refrigerant has a greater impact on the refrigeration performance of the new air-conditioning system. The detection of its leak point is more difficult than that of R12, because the PAG lubricant used in the R-134a system is not "oily", and the previous leak detection method of checking oil stains or wet spots has become undesirable. A fluorescent leak detection technology with the advantages of fast, accurate, clean and safe has emerged. As long as the fluorescent dye is added to the system and then illuminated with a black light, the fluorescent dye on the leak point will emit fluorescence to indicate that the air-conditioning system has a leak. The fluorescent dye can also remain in the system for a long time and play a preventive role. The technology was first invented by Spectronics USA, the parent company of TP in the United States in 1995. The company's dry sheet air-conditioning fluorescent leak detection agent was added to its automotive air-conditioning production line to find leaks in automotive air-conditioning systems.

[0003] Regarding the method of introducing fluorescent dyes into the refrigeration system, the earliest US patent US5149453 reported that a certain amount of fluorescent dye compounds were directly added to the lubricant or refrigerant system. In this way, the fluorescent leak detector circulates with the system and reaches the leak point. When the refrigeration system is exposed to fluorescence, even small leaks can be found. However, this method causes some refrigerant or lubricant to remain outside the system during the filling process, affecting the judgment of the leak point.

[0004] US Patents US5440919 and US5681984 proposed that fluorescent leak detection agents can be attached to a carrier and then added to a desiccant container, and finally introduced into a refrigeration system to achieve the purpose of fluorescent leak detection, but it is necessary to add a step of manually placing the fluorescent leak detection agent absorber on the desiccant container production line, which increases labor costs. US5440919 also proposed that fluorescent dyes can be pre-placed on fabrics and then made into desiccant containers and introduced into the refrigeration system, or in some cases, fluorescent dyes can be attached to desiccant particles by heating and melting, and then introduced into the refrigeration system. However, this method has a relatively high processing temperature, generally above 200°C.

[0005] The Chinese patent CN107737514A applied by the applicant proposes that fluorescent dyes are loaded on desiccant particles, which fundamentally changes the current situation where desiccant and fluorescent leak detection are used separately. It is a groundbreaking innovation, but there are still some shortcomings in use, such as inconvenience in adding and fast fluorescence release of desiccant particles. Summary of the invention

[0006] The technical problem to be solved by the present invention is to solve the problem of inconvenience in adding fluorescent agents for leak detection in air conditioners or other refrigeration systems and the complicated additional manual addition process, and to provide a high-efficiency fluorescent desiccant, a desiccant block or desiccant bag with built-in fluorescent dye, low cost and convenient addition.

[0007] The technical solution adopted by the present invention to solve the above problems is: A fluorescent desiccant relates to desiccant particles. The desiccant particles are loaded with fluorescent dyes. The desiccant particles loaded with fluorescent dyes are pressed into desiccant blocks.

[0008] A fluorescent desiccant relates to desiccant particles. The desiccant particles are loaded with fluorescent dyes. The desiccant particles loaded with fluorescent dyes are loaded into non-woven fabric bags according to quantity to prepare desiccant bags.

[0009] The desiccant particles are selected from one of 3A, 4A, 5A, 13X, AH-7, AH-9, AH-11, Al2O3 or a mixture of two or more thereof.

[0010] The fluorescent dye is selected from one or a mixture of two or more of perylene, naphthalene imide, coumarin, anthracene and thioxanthanes.

[0011] The preparation method of the high-efficiency fluorescent desiccant of the present invention comprises the following steps: selecting formed desiccant particles, fluorescent agent powder and adhesive, mixing them, and placing the mixture into a mold and pressing the mixture into a block.

[0012] The preparation method of the high-efficiency fluorescent desiccant of the present invention comprises the following steps: selecting formed desiccant particles and immersing them in a fluorescent powder solution, loading the fluorescent powder onto the desiccant particles, removing the solvent to form fluorescent desiccant particles, and then putting the fluorescent desiccant particles into a non-woven bag according to the amount to prepare a drying bag.

[0013] The mass concentration of the fluorescent dye is 0.01‰-5% of the desiccant particles.

[0014] The present invention provides a drying module or drying bag with self-contained fluorescence detection, and the fluorescent dye can be directly loaded and processed on the desiccant production line. The fluorescent desiccant and the preparation method thereof also have the following benefits: 1. The preparation method is simple, the process is simple, and each reaction condition is easy to achieve; 2. The fluorescent dye is introduced into the air conditioning and refrigeration system while the desiccant container is filled, saving the labor cost of the air conditioning and refrigeration manufacturer's production line. DETAILED DESCRIPTION

[0015] The present invention will be described in more detail below through examples, but the present invention is not limited to these examples, and the order of the examples does not impose any limitation on the present invention. Example 1

[0016] 10 g of the refrigeration desiccant AH-7 pellets were put into toluene solvent, and the adsorption amount of AH-7 on toluene was determined to be 5 g by the difference method. Perylene was dissolved in 5 g of toluene to prepare a solution with a mass concentration of 0.5%, and then the AH-7 pellets were added thereto and filtered after 2 minutes. The AH-7 pellets adsorbed with the fluorescent leak detector were distilled at 60°C under reduced pressure for 1 hour to finally obtain a fluorescent desiccant block containing perylene. Example 2

[0017] 20 g of desiccant Al2O3 pellets were put into xylene solvent, and the adsorption of Al2O3 on xylene was determined to be 6 g by the difference method. Coumarin was dissolved in 6 g of xylene to prepare a 0.3% solution, and then Al2O3 pellets were added to it and filtered after 5 minutes. The Al2O3 pellets adsorbed with fluorescent leak detection agent were distilled at 100℃ under reduced pressure for 1h to finally obtain desiccant particles containing coumarin fluorescent dye. Example 3

[0018] 10g of desiccant 5A pellets were put into dichloromethane solvent, and the adsorption amount of 5A on dichloromethane was determined to be 4g by the difference method. Naphthalimide was dissolved in 4g of dichloromethane to prepare a 0.2% solution, and then 5A pellets were added thereto and filtered after 2 minutes. After vacuum distillation at 60℃ for 1h, desiccant particles containing naphthalimide fluorescent dye were finally obtained. Example 4

[0019] 100 g of refrigeration desiccant AH-7 and AH-9 pellets (mass ratio 3:7) were put into pentane solvent, and the adsorption amount of pentane by the mixed desiccant was determined to be 30 g by the difference method. Perylene was dissolved in 30 g of pentane to prepare a 0.1% solution, and then AH-7 and AH-9 pellets were added thereto and filtered after 5 minutes. After vacuum distillation at 60°C for 1 hour, mixed desiccant particles containing perylene fluorescent dye were finally obtained. Example 5

[0020] 10g of desiccant Al2O3 and 4A beads (in a mass ratio of 1:1) were put into pentane solvent, and the adsorption amount of pentane by the mixed desiccant was determined to be 3g by the difference method. Naphthalimide and coumarin were dissolved in 3g of pentane in a mass ratio of 1:1 to prepare a 0.3% solution, and then the desiccant was added thereto and filtered after 2 minutes. After vacuum distillation at 50℃ for 1h, mixed desiccant particles containing naphthalimide and coumarin mixed fluorescent dye were finally obtained. Example 6

[0021] 10g of desiccant Al2O3 and 4A pellets (in a mass ratio of 1:1) were added to xylene solvent, and the adsorption of xylene by the mixed desiccant was determined to be 4g by the difference method. Anthracene and coumarin were dissolved in 4g of xylene in a mass ratio of 1:2 to prepare a 0.3% solution, and then AH-11 pellets were added thereto and filtered after 2 minutes. After vacuum distillation at 100℃ for 1h, desiccant particles containing mixed fluorescent dyes of anthracene and coumarin were finally obtained. Example 7

[0022] 20g of desiccant Al2O3 pellets were put into the solvent, and the adsorption amount of Al2O3 on the mixed solvent of chlorobenzene and dichloromethane (volume ratio of 1:2) was determined by the difference method to be 10g. Coumarin was dissolved in 10g of the mixed solvent to prepare a 0.15% solution, and then the desiccant Al2O3 pellets were added thereto and filtered after 2 minutes. After vacuum distillation at 100℃ for 1h, a desiccant containing coumarin fluorescent dye was finally obtained. Example 8

[0023] 20g of refrigeration desiccant AH-9 and AH-7 (mass ratio 1:1) pellets were put into the solvent, and the adsorption capacity of the mixed desiccant to the mixed solvent of chlorobenzene and dichloromethane (volume ratio 1:2) was determined by the difference method to be 10g. Coumarin was dissolved in 10g of the mixed solvent to prepare a 0.18% solution, and then the desiccant pellets were added thereto and filtered after 2 minutes. After vacuum distillation at 100℃ for 1h, a mixed desiccant containing coumarin fluorescent dye was finally obtained. Example 9

[0024] 10 g of pellets of refrigeration desiccants AH-9 and AH-7 (mass ratio 1:1) were solid-solid mixed with 0.018 g of coumarin, and then formed into a columnar desiccant module by adding an adhesive, and finally a desiccant module containing coumarin fluorescent dye was obtained. Example 10

[0025] 10g of desiccant Al2O3 beads were solid-solid mixed with 0.015g of perylene and 0.005g of anthracene fluorescein, and then formed into a columnar desiccant module by adding a binder, thereby finally obtaining a desiccant module containing coumarin fluorescent dye.

[0026] Comparative Example 1 The same ingredients as in Example 9 are used to prepare fluorescent agent desiccant particles.

[0027] Comparative Example 2 The same ingredients as in Example 10 are used to prepare fluorescent agent desiccant particles. Embodiment 11

[0028] 10 g of desiccant 5A pellets were solid-mixed with 0.025 g of naphthalimide fluorescent dye, and then packaged in a non-woven bag to obtain a desiccant bag containing naphthalimide fluorescent dye.

[0029] Comparative Example 3 The same ingredients as in Example 11 are used to prepare fluorescent agent desiccant particles.

[0030] The desiccants containing fluorescent dyes prepared in the above Examples 1-11 were added to the air conditioning refrigeration system and operated for a period of time, and then the welding points (suspicious leaks) of the system were irradiated with ultraviolet light, so as to determine the location of the leak according to the fluorescence emitted by the fluorescent dye under ultraviolet excitation. In the refrigeration system, the fluorescent dyes coated on the desiccant are diluted and dissolved with the circulation of the refrigerant and lubricating oil liquid to reach the identification concentration, and the leak point is detected accurately and quickly during the detection, and the detection accuracy rate reaches 100%.

Claims

1. A high-efficiency fluorescent desiccant, relating to desiccant particles, characterized in that: The desiccant particles are loaded with fluorescent dyes, and the desiccant particles loaded with fluorescent dyes are pressed into desiccant blocks.

2. A high-efficiency fluorescent desiccant, involving desiccant particles, characterized in that: The desiccant particles are loaded with fluorescent dyes, and the desiccant particles loaded with fluorescent dyes are loaded into non-woven fabric bags according to the amount to prepare desiccant bags.

3. A high-efficiency fluorescent desiccant according to claim 1 or 2, characterized in that: The desiccant particles are selected from one of 3A, 4A, 5A, 13X, AH-7, AH-9, AH-11, Al2O3 or a mixture of two or more thereof.

4. A high-efficiency fluorescent desiccant according to claim 1 or 2, characterized in that: The fluorescent dye is selected from one or a mixture of two or more of perylene, naphthalene imide, coumarin, anthracene and thioxanthanes.

5. The method for preparing a high-efficiency fluorescent desiccant according to claim 1, characterized in that: Select the formed desiccant particles, fluorescent agent powder and adhesive, mix them, put the mixture into a mold and press them into blocks.

6. The method for preparing a high-efficiency fluorescent desiccant according to claim 2, characterized in that: Select the formed desiccant particles and immerse them in the fluorescent powder solution. The fluorescent powder is loaded onto the desiccant particles. The solvent is then removed to form fluorescent desiccant particles. The fluorescent desiccant particles are loaded into a non-woven bag according to the amount to form a desiccant bag.

7. The method for preparing a high-efficiency fluorescent desiccant according to claim 5 or 6, characterized in that: The mass concentration of the fluorescent dye is 0.01‰-5% of the desiccant particles.