A hot-pressing recycling method for dry-type transformer decommissioned epoxy insulation material

Abstract

This invention discloses a hot-pressing recycling method for decommissioned epoxy insulation material from dry-type transformers, relating to the field of transformer material recycling technology. The hot-pressing recycling method involves: cutting the decommissioned epoxy insulation material from the dry-type transformer into blocks and grinding it into powder; uniformly adding triethanolamine to the powder, with the powder mass percentage being 98.0-99.4% and the triethanolamine mass percentage being 0.6-2.0%; and hot-pressing at 170-190℃ for 6-8 hours to obtain new epoxy insulation material. The hot-pressing recycling method provided by this invention enables the complete recycling of decommissioned epoxy insulation material from dry-type transformers. The recycled new epoxy insulation material has a dielectric constant that meets the requirements for use as insulation material, solving the problem of unrecoverable epoxy insulation material from abandoned dry-type transformers, effectively saving resources, and having practical application value.

Description

Technical Field

[0001] This invention relates to the field of recycling technology for epoxy insulation materials from decommissioned transformers, and more particularly to a hot-pressing recycling method for epoxy insulation materials from decommissioned dry-type transformers. Background Technology

[0002] Anhydride-cured epoxy resins are widely used in fields such as epoxy insulation materials for dry-type transformers due to their excellent insulation properties, good physicochemical properties, and good stability after curing. However, most existing epoxy insulation materials have a dense three-dimensional cross-linked structure, making them difficult to recycle effectively. This often leads to the complete disposal of electrical equipment after its decommissioning, causing environmental pollution and resource waste.

[0003] Currently, the epoxy resin materials commonly used in the electrical equipment field are mainly made from bisphenol A (BPA). However, BPA-based epoxy resins, after curing with acid anhydrides, cannot be effectively recycled and are considered low-value materials. This contradicts the national goal of "carbon peaking and carbon neutrality" and the development requirements for green electricity, hindering industrial applications. Current research has found that triethanolamine can catalyze the transesterification reaction of acid anhydride-cured epoxy resins at high temperatures, allowing powdered epoxy insulation materials to re-crosslink and cure under high temperature and high pressure conditions.

[0004] In view of the above, it is necessary to develop a recycling method for anhydride-cured epoxy resin insulation materials. While ensuring the basic thermal and electrical properties of the materials, the waste materials can be recycled by hot pressing to obtain new epoxy insulation materials that can be used in the field of electrical equipment insulation materials. Summary of the Invention

[0005] To address the above shortcomings, this invention provides a hot-pressing recycling method for decommissioned epoxy insulation materials from dry-type transformers. This method enables the complete recycling of decommissioned epoxy insulation materials from dry-type transformers, and the resulting new epoxy insulation material has a dielectric constant that meets the requirements for use as insulation materials. The specific technical solution is as follows:

[0006] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0007] (1) Cut the decommissioned epoxy insulation material on the dry-type transformer into blocks and grind it into powder;

[0008] (2) The powder is placed in a mold and triethanolamine is evenly dripped into the powder. After hot pressing at 170-190°C for 6-8 hours, a new epoxy insulation material is obtained. The powder accounts for 98.0-99.4% by mass percentage, and the triethanolamine accounts for 0.6-2.0%.

[0009] Furthermore, the epoxy insulation material is a traditional anhydride-cured epoxy resin that has been decommissioned from dry-type transformers.

[0010] Furthermore, the mold is a circular metal mold, and a metal plate is placed on top of the mold before hot pressing.

[0011] Furthermore, the hot pressing is performed using a flat vulcanizing machine.

[0012] Furthermore, the pressure of the hot pressing is 10-15 MPa.

[0013] Preferably, the temperature is 180°C.

[0014] Preferably, the powder accounts for 98.8% and the triethanolamine accounts for 1.2%.

[0015] A hot-pressing method for recycling epoxy insulation material from decommissioned dry-type transformers.

[0016] A hot-pressing recycling method for epoxy insulation material from decommissioned dry-type transformers is used to recycle the recovered epoxy insulation material, which is then applied in the field of epoxy insulation materials for electrical equipment.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The hot-press recycling method for decommissioned epoxy insulation materials of dry-type transformers provided by this invention achieves complete recycling while ensuring the thermal and electrical properties of the materials. After hot-press recycling, new epoxy resin insulation materials can be directly obtained, and the measured dielectric constant meets the requirements for use of insulation materials. This solves the problem of the inability to recycle insulation materials in waste electrical equipment, effectively saves resources, and has practical application value. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0020] Figure 1 This is a schematic diagram showing the epoxy insulation material cut into blocks after decommissioning from the dry-type transformer of the present invention.

[0021] Figure 2 This is a schematic diagram of the new epoxy insulation material obtained by hot pressing and recycling according to the present invention. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0023] Example 1

[0024] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0025] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0026] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 170°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. The powder accounts for 99.4% by mass percentage, and the triethanolamine accounts for 0.6%.

[0027] Example 2

[0028] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0029] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0030] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 180°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. The powder accounts for 99.4% by mass percentage, and the triethanolamine accounts for 0.6%.

[0031] Example 3

[0032] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0033] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0034] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 190°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. The powder accounts for 99.4% by mass percentage, and the triethanolamine accounts for 0.6%.

[0035] Example 4

[0036] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0037] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0038] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 180°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. The powder accounts for 98.8% by mass percentage, and the triethanolamine accounts for 1.2%.

[0039] Example 5

[0040] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0041] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0042] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 180°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. The powder accounts for 98.0% by mass percentage, and the triethanolamine accounts for 2.0%.

[0043] Example 6

[0044] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0045] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0046] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 175°C and 5MPa for 8 hours, a new epoxy insulation material is obtained. The powder accounts for 98.5% by mass percentage, and the triethanolamine accounts for 1.5%.

[0047] Example 7

[0048] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0049] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0050] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 185°C and 15MPa for 8 hours, a new epoxy insulation material is obtained. The powder accounts for 98.5% by mass percentage, and the triethanolamine accounts for 1.5%.

[0051] Comparative Example 1

[0052] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0053] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0054] (2) The above powder is placed in a circular metal mold, and 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) is evenly dripped into the powder. A metal plate is then placed on top of the mold, and the mold is placed in a flat vulcanizing machine. After hot pressing at 170°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. By mass percentage, the powder accounts for 99.4%, and (DMP-30) accounts for 0.6%.

[0055] Comparative Example 2

[0056] A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers includes the following steps:

[0057] (1) Cut the epoxy insulation material after it is decommissioned from the dry-type transformer into blocks and grind it into powder in a vibrating ball mill.

[0058] (2) The above powder is placed in a circular metal mold, and triethanolamine is evenly dripped into the powder. A metal plate is then placed on top of the mold and placed in a flat vulcanizing machine. After hot pressing at 170°C and 10MPa for 6 hours, a new epoxy insulation material is obtained. The powder accounts for 97% by mass percentage, and the triethanolamine accounts for 3%.

[0059] The dielectric properties of the new epoxy resin material obtained by hot-pressing recycling in the example were tested, and the results are shown in Table 1:

[0060] Table 1. Dielectric properties of the new epoxy resin materials obtained by hot-pressing recovery in each embodiment.

[0061]

[0062] Electrical equipment requires insulating materials to have low dielectric loss (a dielectric loss below 0.004 is required to meet the insulation material requirements for electrical equipment). Based on the above embodiments, comparative examples, and experimental test data, the dielectric properties of each embodiment are good and can be reused in the field of insulating materials for electrical equipment. Among these, a hot-pressing temperature of 180℃ and the mass percentages of the components in the hot-pressed recovered anhydride-cured epoxy resin—98.8% anhydride-cured epoxy resin powder and 1.2% triethanolamine—are considered suitable conditions. In Comparative Example 1, replacing triethanolamine with the curing accelerator DMP-30 resulted in a significant increase in dielectric loss in the hot-pressed recovered material, rendering it unusable. In Comparative Example 2, without increasing the temperature, simply adding more triethanolamine did not meet the required dielectric loss.

[0063] The hot-pressing recycling method for decommissioned epoxy insulation materials from dry-type transformers provided by this invention yields epoxy resin materials whose dielectric constant meets the requirements for use as insulation materials. These materials can be reused in the field of epoxy insulation materials for electrical equipment, solving the problem of unrecoverable insulation materials in waste electrical equipment, effectively saving resources, and having practical application value.

[0064] It should be noted that the epoxy insulation material used in decommissioned dry-type transformers is the traditional anhydride-cured epoxy resin that was removed from the dry-type transformers.

[0065] It should be noted that the decommissioned epoxy insulation material came from Shanghai Anaiji Chemical Co., Ltd., and the triethanolamine was purchased from Chengdu Kelong Chemical Co., Ltd.

[0066] It should be noted that the dielectric properties of the material were measured using a broadband dielectric spectrometer, which is from NOVOCONTROL GmbH, Germany; the GT200 vibratory ball mill and the flat vulcanizing machine are from Bruker GmbH, Germany.

[0067] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for hot-pressing recycling of epoxy insulation material from decommissioned dry-type transformers, characterized in that, Includes the following steps: (1) Cut the traditional acid anhydride-cured epoxy resin that was decommissioned from the dry-type transformer into blocks and then grind it into powder. (2) The powder is placed in a mold and triethanolamine is evenly dripped into the powder. After hot pressing at 170-190°C for 6-8 hours, epoxy insulation material is obtained. The powder accounts for 98.0-99.4% by mass percentage and the triethanolamine accounts for 0.6-2.0%.

2. The hot-pressing recycling method for epoxy insulation material of decommissioned dry-type transformers according to claim 1, characterized in that, The mold is a circular metal mold, and a metal plate is placed on top of the mold before hot pressing.

3. The hot-pressing recycling method for epoxy insulation material of decommissioned dry-type transformers according to claim 1, characterized in that, The hot pressing is carried out using a flat vulcanizing machine.

4. The hot-pressing recycling method for epoxy insulation material of decommissioned dry-type transformers according to claim 1, characterized in that, The pressure of the hot pressing is 10-15 MPa.

5. The hot-pressing recycling method for epoxy insulation material of decommissioned dry-type transformers according to claim 1, characterized in that, The temperature is 180°C.

6. The hot-pressing recycling method for epoxy insulation material of decommissioned dry-type transformers according to claim 1, characterized in that, The powder accounts for 98.8% of the composition, and the triethanolamine accounts for 1.2%.

7. An epoxy insulation material recovered by a hot-pressing recycling method for decommissioned epoxy insulation material of a dry-type transformer as described in any one of claims 1 to 6.

8. The application of epoxy insulation material recovered by the hot-pressing recycling method of the decommissioned epoxy insulation material of dry-type transformers as described in any one of claims 1 to 6 in the field of epoxy insulation materials for electrical equipment.

Images