An antiscalant granule, a method for preparing the same, and a water heater

Abstract

The present application provides a kind of scale inhibitor particles and its preparation method and a kind of water heater, the scale inhibitor particles include scale inhibitor and binder, the content of scale inhibitor is 60%~98%, the content of binder is 2%~40%, the solubility of scale inhibitor in water below 90 DEG C is less than 5g / 100g, the solubility of binder in water below 90 DEG C after solidification is less than the solubility of scale inhibitor, the swelling degree of the particle in water below 90 DEG C is less than 12%, the hydrolysis degree of binder in water below 90 DEG C after solidification is less than 1%.

Description

[0001] This application is a divisional application, with parent application number 201810742893.5 and invention title "A scale inhibitor particle and its preparation method". Technical Field

[0002] This invention relates to scale inhibitor particles and a method for preparing the same. Specifically, this invention provides scale inhibitor particles with a stable dissolution rate, enabling long-term use while maintaining the desired scale inhibition effect. This invention also relates to a water heater containing these scale inhibitor particles. Background Technology

[0003] Water quality varies across regions. Water may contain calcium and magnesium ions, which can form limescale during use. This is especially true in the water heater industry, where heating water exacerbates limescale formation. To prevent limescale buildup, scale inhibitors are typically used to treat the water. To extend the lifespan of scale inhibitors, current technology often involves preparing them into blocks or granules along with other ingredients. However, existing scale inhibitors often suffer from problems such as the granules or blocks being easily broken, leading to them being flushed away and resulting in insufficient lifespan. Summary of the Invention

[0004] Technical issues

[0005] In existing technologies, scale inhibitors containing scale inhibitors are typically installed before the water heater. Tap water is softened by the scale inhibitor before entering the water heater, thereby improving water quality and extending the water heater's lifespan. However, scale inhibitors take up space and affect the aesthetics of the room, thus necessitating the development of novel scale inhibitors. The inventors focused on this issue, aiming to develop a scale inhibitor that can be used both outside and inside the water heater. If the scale inhibitor can be used inside the water heater, the aforementioned problems can be solved.

[0006] However, when scale inhibitors are used inside water heaters, the following problems arise. Most scale inhibitors operate at room temperature and degrade rapidly at high temperatures. Therefore, when used in water heaters, which typically operate at high temperatures for extended periods, scale inhibitors capable of long-term operation at high temperatures must be used. Furthermore, since the scale inhibitor is built into the water heater, it is difficult for ordinary users to replace it themselves; when it runs out, it must be replenished by a professional. This necessitates a long service life for the scale inhibitor to minimize the inconvenience caused by frequent replenishment.

[0007] Secondly, the scale inhibitor particles placed inside the water heater's inner tank will occupy the tank's water storage space. The more scale inhibitor particles are placed, the longer the scale inhibitor's lifespan will be, and the more space it will occupy in the inner tank. Therefore, it is desirable to put a sufficient amount of scale inhibitor particles in the smallest possible tank. However, if the density of the scale inhibitor particles is too high, it will cause poor water flow and also affect the scale inhibitor's scale inhibition effect.

[0008] The purpose of this invention is to provide a scale inhibitor granule. This aims to solve the aforementioned technical problems. Furthermore, the scale inhibitor granules of this invention can prevent particle breakage, thereby avoiding the scale inhibitor components being washed away by water flow. Another objective of this invention is to improve the service life of the scale inhibitor granules. In addition, this invention also provides a scale inhibitor with a specific structure. By giving the scale inhibitor of this invention a specific structure, the scale inhibitor can be uniformly released from the scale inhibitor granules, improving the scale inhibition effect and extending the service life.

[0009] The present invention also aims to provide a water heater with a built-in scale inhibitor device in its inner tank. The scale inhibitor device contains scale inhibitor particles. The parameters such as the shape and structure of the scale inhibitor particles, the weight of the scale inhibitor, and the weight of the adhesive are configured to ensure that the scale inhibitor particles per unit area in the tank containing the scale inhibitor particles have a better scale inhibition effect and lifespan, while occupying less space.

[0010] Technical solution

[0011] This invention provides scale inhibitor particles, the scale inhibitor particles comprising a scale inhibitor and a binder, wherein the content of the scale inhibitor is 60% to 98%, preferably 60% to 95%, and the content of the binder is 2% to 40%, preferably 5% to 40%. The solubility of the scale inhibitor in water below 90°C is less than 5 g / 100 g, and the solubility of the binder in water below 90°C after curing is lower than the solubility of the scale inhibitor. The swelling degree of the particles in water below 90°C is less than 12%, and the degree of hydrolysis of the binder in water below 90°C after curing is less than 1%.

[0012] In the scale inhibitor particles of this invention, the scale inhibitor content can be maximized by reducing the binder content, thereby extending the lifespan of the scale inhibitor particles. However, simply increasing the scale inhibitor content can lead to insufficient particle strength and easy breakage. To address this, the inventors discovered that by selecting a scale inhibitor with a solubility of less than 5 g / 100 g water, further reducing the binder solubility to below that of the scale inhibitor, controlling the swelling degree of the scale inhibitor particles in water below 90°C to be less than 12%, and selecting a binder with a hydrolysis degree of less than 1% in water below 90°C after curing, the binder can maintain its skeletal structure even when the scale inhibitor dissolves, thereby extending the service life of the scale inhibitor particles.

[0013] The inventors have also discovered that when a scale inhibitor with specific polar groups is used, it can interact with the binder to suppress the expansion rate of the scale inhibitor particles, thereby better solving the technical problem of the present invention. The scale inhibitor may contain at least one of the following polar groups or their salts: phosphate, phosphonic acid, phosphate ester, phosphoryl, carboxyl, and sulfonic acid. Preferably, the scale inhibitor is a polyphosphate, an organophosphonate, maleic anhydride, or polyaspartic acid.

[0014] In addition, the present invention also provides a method for preparing scale inhibitor particles and scale inhibitor particles having a specific structure.

[0015] The scale inhibitor particles of the present invention may consist solely of a scale inhibitor and a binder. Without affecting the technical effects of the present invention, the scale inhibitor particles of the present invention may contain other additives.

[0016] To improve the service life of scale inhibitor particles, the ratio of scale inhibitor to binder in the scale inhibitor particles of this invention decreases gradually from the center to the outer surface. This structure results in a lower scale inhibitor content on the outer surface of the particles, but a larger contact area between the scale inhibitor and water. As the scale inhibitor dissolves, the particle size decreases, and the contact area between the scale inhibitor and water also decreases, but the scale inhibitor content increases, thereby compensating for the reduced dissolution rate caused by the smaller contact area. This structure allows the scale inhibitor to dissolve at a uniform rate, ensuring effective scale inhibition and extending the service life of the scale inhibitor particles.

[0017] As a specific example, the scale inhibitor particles may have a core layer, an intermediate layer, and an outer layer. The scale inhibitor in the core layer is 95% to 100% by weight, and the binder is 0% to 5% by weight. The scale inhibitor in the intermediate layer is 90% to 95% by weight, and the binder content is 5% to 10% by weight. The scale inhibitor in the outer layer is 80% to 90% by weight, and the binder content is 10% to 20% by weight.

[0018] The present invention also provides a water heater, the water heater comprising an inner tank and a scale inhibitor device disposed within the inner tank, the scale inhibitor device containing the aforementioned scale inhibitor particles.

[0019] Technical effect

[0020] The scale inhibitor particles of this invention provide a long-term, sustained-release effect, ensuring that the particle skeleton remains intact during the dissolution process. In particular, even when used in hot water, the scale inhibitor particles of this invention can be used for an extended period while still achieving the desired scale inhibition effect. Attached Figure Description

[0021] Figure 1 These are photos of calcium citrate scale inhibitor blocks at the beginning of immersion in water at room temperature (25℃), 40℃, and 90℃, respectively.

[0022] Figure 2 These are photographs of the scale inhibitor particles from Example 1 after being soaked in water for 24 hours at room temperature (25°C), 40°C, and 90°C, respectively.

[0023] Figure 3 The photos show the block-shaped pure scale inhibitor before and after passing through 5 tons of water.

[0024] Figure 4 These are photos of the scale inhibitor particles from Example 1 before and after passing through 5 tons of water;

[0025] Figure 5 This is a schematic diagram of the scale inhibitor particles in Example 5 of the present invention;

[0026] Figure 6 This is a schematic diagram of the inner tank of the water heater of the present invention. Detailed Implementation

[0027] The specific embodiments of the present invention will be further described below with reference to specific examples.

[0028] The scale inhibitor particles of the present invention are made by using a slightly soluble scale inhibitor, and are composed of the following components by weight percentage: scale inhibitor 60% to 98%, preferably 60% to 95%; binder 40% to 2%, preferably 5% to 40%. The scale inhibitor is a slightly soluble scale inhibitor, such as calcium citrate, ethylenediaminetetramethylenephosphonic acid (EDTMPA), or one or more of these. The binder is at least one of epoxy resin, polyacrylate, polyurethane, polyvinyl alcohol, and their curing agents.

[0029] This invention also provides a method for preparing a scale inhibitor. The scale inhibitor particles can be formed by roll forming, extrusion spheroidization, screw extrusion, and isostatic pressing. The roll forming step includes: mixing the scale inhibitor, binder, and water according to the above proportions and adding the mixture to a ball forming machine to prepare mother balls. After the mother balls are prepared, they are placed in the ball forming machine, and then binder and water are sprayed into the machine, followed by powder addition. This process is repeated until the mother balls grow to the desired size, at which point preparation is stopped. The mixture is then dried in an oven at 60-100℃ for 4-12 hours to obtain the scale inhibitor particles of this invention. The screw extrusion method involves kneading the above mixed sample in a kneader until uniformly mixed. The sample is then prepared using a screw extruder and dried in an oven at 60-100℃ for 4-12 hours to obtain the scale inhibitor particles of this invention.

[0030] This invention utilizes a slightly soluble scale inhibitor combined with a curable adhesive to ensure that the scale inhibitor particles remain stable during water treatment. This prevents the scale inhibitor particles from being dispersed due to excessive dissolution of the adhesive and scale inhibitor, thus ensuring a long service life.

[0031] like Figure 6 As shown, the inner tank 10 of the water heater of the present invention includes a scale-inhibiting device 20 disposed therein; the scale-inhibiting device 20 contains a certain amount of scale-inhibiting agent particles. Each scale-inhibiting agent particle weighs 0.1-300mg; the bulk density per unit volume of the area of ​​the scale-inhibiting device containing the scale-inhibiting agent particles is 0.5-1.5g / cm³. 3 Within the specified range. The scale inhibitor particles are preferably spherical with a diameter of 0.5-10 mm.

[0032] Preferably, the scale inhibitor particles have a core layer and an outer layer covering the core layer. From the outer layer to the core layer, the scale inhibitor particles include a scale inhibitor and a binder. The weight percentage of the scale inhibitor increases gradually, while the weight percentage of the binder decreases gradually. From the start of consumption to the end of consumption, the surface area of ​​each scale inhibitor particle decreases. If the scale inhibitor content is consistent from the outer layer to the core layer, the scale inhibitor content decreases over time, and the scale inhibition effect decreases at different time periods. This embodiment utilizes the gradient structure of the scale inhibitor content to ensure that the scale inhibitor can be released in a uniform amount at different time periods, ensuring consistent scale inhibition effect at different time stages.

[0033] Preferably, the scale inhibitor further includes an intermediate layer located between the core layer and the outer layer, wherein the core layer has a thickness of 0.5-5 mm, the intermediate layer has a thickness of 0.5 mm-5 mm, and the outer layer has a thickness of 0.5 mm-5 mm.

[0034] The binder in the scale inhibitor particles preferably has a skeleton structure. After the scale inhibitor in the scale inhibitor particles is consumed, the binder can still remain in the scale inhibition device to avoid contaminating the water in the inner tank.

[0035] Scale inhibitor granules placed inside the water heater's inner tank occupy water storage space. The more granules are placed, the longer the lifespan of the scale inhibitor, but the more space it occupies. Therefore, it's desirable to pack a sufficient amount of scale inhibitor granules into a small tank. However, excessive granule density can obstruct water flow, also affecting the scale inhibitor's effectiveness. By configuring parameters such as the shape and structure of the scale inhibitor granules, their weight, and the weight of the binder, we can ensure optimal scale inhibition per unit area within the scale inhibitor device, while also maintaining a long lifespan and minimizing space occupation.

[0036] In this embodiment, the shape and structure of the scale inhibitor particles, the weight of the scale inhibitor, the weight of the binder, and other parameters were designed to ensure that the scale inhibitor particles per unit area in the tank containing the scale inhibitor particles have a better scale inhibition effect and lifespan, while occupying less space.

[0037] Example

[0038] Swelling test method

[0039] The swelling degree of scale inhibitor particles at different water temperatures was tested using the swelling equilibrium method. Five grams of filter media were weighed and placed in 100 ml of water, then allowed to stand at different temperatures. The scale inhibitor particles absorb water during immersion. After water absorption equilibrium was reached, the volume change of the scale inhibitor particles before and after water absorption was measured (V0 before water absorption, V1 after water absorption). The swelling degree is represented by Q.

[0040] Q = (V1 - V0) / V0 * 100%

[0041] For strip-shaped samples, the degree of swelling can be directly determined by the change in diameter (D0 before water absorption, D1 after water absorption). The degree of swelling is represented by Q.

[0042] Q = (D1 - D0) / D0 * 100%

[0043] Hydrolysis degree test method

[0044] The degree of hydrolysis was tested using the weight loss method. The adhesive was cured separately according to the required ratio, without mixing with the powder. After curing, a certain weight of the adhesive was weighed (m1) and immersed in water at 90°C. It was removed, dried, and weighed periodically until the weight remained constant. The experiment was then concluded, and the weight was recorded as m2. The degree of hydrolysis was then calculated using the following formula:

[0045] Degree of hydrolysis = (m1 - m2) / m1 * 100%

[0046] Dissolution rate test method

[0047] The dissolution rate of the scale inhibitor particles was determined by placing a 10g sample in 100ml of water and measuring the concentration of calcium ions after soaking in the water for 30 minutes and 24 hours.

[0048] Water-soluble scale inhibition life test method

[0049] Place 100g of sample into a 10-inch filter bottle, start the water flow test, and use a flow rate of 5L / min to flow the water. After passing through 20 tons and 40 tons of water, test the weight loss rate and static scale inhibition effect to confirm the filter media life.

[0050] Example 1

[0051] Calcium citrate was selected as the scale inhibitor in the scale inhibitor granules, and the binder was AB type epoxy resin (Henkel, model: Loctite 7255). The scale inhibitor: binder ratio was 9:1, and a certain amount of water was added, making the scale inhibitor: water ratio 1.5:1. Strip-shaped granule samples were prepared by screw extrusion, with a sample diameter of 1.5 mm and a length of 3-5 mm. The solubility of calcium citrate in water at 25℃ was 0.1 g / 100 g, indicating slight soluble in water. The swelling degree and hydrolysis degree of the sample at different temperatures were tested, and the test results are shown in Table 1. The solubility of the scale inhibitor granules at different temperatures is shown in Table 1. Figure 1 and Figure 2 As shown. Figure 1 These are photos of pure calcium citrate scale inhibitor blocks at the beginning of immersion in water at room temperature (25℃), 40℃, and 90℃. Figure 1 It can be seen that the calcium citrate block underwent significant dissolution. Figure 2 These are photographs of the scale inhibitor particles from Example 1 after being soaked in water for 24 hours at room temperature (25°C), 40°C, and 90°C, respectively. Figure 1 In comparison, it can be seen that the scale inhibitor particles of this application can exist stably in aqueous solution, thereby reducing the waste of scale inhibitor.

[0052] During the soaking process, the stability of the scale inhibitor particles at different temperatures was also tested. Table 1 shows the swelling rates of the scale inhibitor particles of Example 1 after soaking in water for 12 hours and 24 hours at room temperature (25°C), 40°C, and 90°C, respectively.

[0053] Table 1. Swelling rate of scale inhibitor particles in Example 1 at different temperatures and times.

[0054] Temperature (°C) 25 40 90 Swelling degree (%) after soaking for 12 hours 0.58 0.65 0.65 Swelling degree (%) after soaking for 24 hours 0.6 0.64 0.63

[0055] The inventors also tested the adhesive, confirming that it remained stable in water at different temperatures, thus ensuring that the scale inhibitor was well fixed and not washed away.

[0056] The test method is as follows: Epoxy resin components A and B are mixed and crosslinked. 1g of each crosslinked sample is weighed and placed in a beaker, then 200ml of water is added. The samples are then placed in room temperature water (i.e., 25℃ water), 40℃ water, and 90℃ water, respectively. After standing for 24 hours, the samples are dried and weighed. The weight of the adhesive is recorded, and the statistical results are shown in Table 2.

[0057] Table 2. Degree of hydrolysis of adhesive after curing at different temperatures

[0058] Temperature (°C) Initial weight (g) Weight (g) after 24 hours Degree of hydrolysis (%) 25 1.0051 1.0048 0.03 40 1.0032 1.0031 0.01 90 1.0029 1.0027 0.02

[0059] It can be seen that after the AB components crosslink, the adhesive can exist stably in water and will not hydrolyze when soaked in water, thus maintaining the shape and performance of the particles more stably.

[0060] In addition, the inventors tested the dissolution rate of calcium citrate powder and the scale inhibitor particles of Example 1, and the test results are shown in Table 3. Table 3 shows that the scale inhibitor particles of Example 1 can remain stable and will not dissolve excessively.

[0061] Table 3 Comparison of dissolution rates of scale inhibitor particles and pure scale inhibitor

[0062] Sample Name Block scale inhibitor Scale inhibitor particles Solubility (g / 100g) after soaking for 30 minutes 0.055 0.03 Solubility (g / 100g) after soaking for 24 hours 0.065 0.03

[0063] The inventors not only studied the particle state of the scale inhibitor in a static state, but also evaluated its dissolution life in a water-fluid state.

[0064] Figure 3 The images show photos of the block-shaped pure scale inhibitor before and after rinsing with 5 tons of water. 10g each of the block-shaped and granular scale inhibitor were weighed out for rinsing experiments. As the rinsing time increased, the amount of the block-shaped scale inhibitor decreased significantly, eventually leaving only a small amount.

[0065] Figure 4 These are photographs of the scale inhibitor particles from Example 1 before and after rinsing with 5 tons of water. Figure 4 It can be seen that the scale inhibitor particles in Example 1 remained very intact and had a good morphology even after passing through 5 tons of water.

[0066] To better characterize its lifespan, the inventors also weighed the sample after it had been submerged in 5 tons of water, and the results are as follows:

[0067] After passing through 5 tons of water, the block-shaped scale inhibitor weighed 1.53g, with a weight loss of 84.7%; while the scale inhibitor granules of Example 1 weighed 5.89g after passing through 5 tons of water, with a weight loss of 41.1%. Therefore, the lifespan of the scale inhibitor granules of Example 1 is more than twice that of the block-shaped pure scale inhibitor.

[0068] Example 2

[0069] Ethylene diaminetetramethylenephosphonic acid (EDTMPA) was selected as the scale inhibitor in the granules. EDTMPA is a white crystalline powder at room temperature with a melting point of 215-217℃. It is slightly soluble in water, with a solubility of less than 5% at room temperature. It has a strong ability to chelate metal ions, effectively preventing scale formation. This scale inhibitor has strong water absorption. The binder is AB type epoxy resin (Henkel, Loctite 7255). The ratio of scale inhibitor to binder is 9:1, with the addition of a certain amount of water to achieve a scale inhibitor:water ratio of 1.5:1. Spherical granule samples were prepared by roll forming, with a sample diameter of approximately 3-4 mm. The swelling degree and hydrolysis degree of the scale inhibitor granules from Example 2 were tested at different temperatures, and the test results are shown in Table 4.

[0070] Example 3

[0071] Calcium citrate was selected as the scale inhibitor in the scale inhibitor particles. The binder was AB type epoxy resin (Henkel, Loctite 7255). The scale inhibitor: binder ratio was 7:3, and a certain amount of water was added to make the scale inhibitor: water ratio 1.5:1. Spherical particle samples were prepared by roll forming, with a sample diameter of approximately 3-4 mm. The swelling degree and hydrolysis degree of the scale inhibitor particles of Example 3 were tested at different temperatures, and the test results are shown in Table 4.

[0072] Example 4

[0073] EDTMPA was selected as the scale inhibitor in the scale inhibitor particles. Polyvinyl alcohol was chosen as the binder, and the required curing agent was mixed in simultaneously, along with a certain amount of water. The selected ratio was scale inhibitor: binder = 7:3, with a further addition of water, making the scale inhibitor: water ratio 1.5:1. Spherical particle samples with a diameter of 1.5 mm were prepared using the rolling ball method. The swelling degree and hydrolysis degree of the scale inhibitor particles from Example 2 were tested at different temperatures, and the test results are shown in Table 4.

[0074] Example 5

[0075] The scale inhibitor particles are manufactured using the scale inhibitor and binder from Example 1, the difference being that, as Figure 5As shown, the scale inhibitor particles were prepared into a multi-layered structure. The particles have a core layer 3, an intermediate layer 2, and an outer layer 1. The core layer 3 contains 96 wt% scale inhibitor, 4 wt% binder, and has a thickness of 2 mm. The intermediate layer 2 contains 90 wt% scale inhibitor, 10 wt% binder, and has a thickness of 2 mm. The outer layer 1 contains 85 wt% scale inhibitor, 15 wt% binder, and has a thickness of 2 mm. The particles were prepared by first preparing the core layer 3, then the intermediate layer 2, and finally the outer layer 1. Compared to Example 1, the scale inhibitor particles of Example 5 show more uniform scale inhibitor release, with a weight loss of 39.0% after passing through 5 tons of water, which can further improve the service life of the scale inhibitor. When these scale inhibitor particles are placed in the scale inhibitor tank of a water heater, they still maintain a good scale inhibition effect during use in the water heater, with a weight loss of 41.2% after passing through 5 tons of water at 70°C.

[0076]

[0077] As shown in the table above, when the solubility of the scale inhibitor in water below 90°C is less than 0.1g / 100g, the solubility of the adhesive in water below 90°C after curing is less than the solubility of the scale inhibitor, the swelling degree of the particles in water below 90°C is less than 12%, and the degree of hydrolysis of the adhesive in water below 90°C after curing is less than 1%, the scale inhibitor has a smaller weight loss after passing through 5 tons of water and has a longer service life.

[0078] In the above experiment, 10g of scale inhibitor was used, which could provide scale inhibition for approximately 10 tons of water. The average user's annual water consumption for a water heater is approximately 30-50 tons. If 100g of the scale inhibitor of this invention is used, it can provide scale inhibition for approximately 100 tons of water. Therefore, the scale inhibitor of this invention can be used for approximately two years or more, significantly reducing the frequency of scale inhibitor replenishment.

Claims

1. A scale inhibitor particle for use in a water heater, the scale inhibitor particle comprising a scale inhibitor and a binder, characterised in that: The content of the scale inhibitor is 60% to 98%, the content of the adhesive is 2% to 40%, the solubility of the scale inhibitor in water below 90℃ is less than 5g / 100g, the solubility of the adhesive in water below 90℃ after solidification is less than the solubility of the scale inhibitor, the swelling degree of the particle in water below 90℃ is less than 12%, the hydrolysis degree of the adhesive in water below 90℃ after solidification is less than 1%, The scale inhibitor is selected from at least one of the following scale inhibitors: citrate, polyphosphate and organic phosphonate, The adhesive can remain after the scale inhibitor in the scale inhibitor particle is consumed.

2. The scale inhibitor particles of claim 1, wherein The adhesive has a skeleton structure.

3. The scale inhibitor particles of claim 1 or 2, wherein In the particle, the weight percentage of the scale inhibitor is gradiently increased from the outer surface to the center, and the weight percentage of the adhesive is gradiently decreased.

4. The scale inhibitor particles of claim 1 or 2, wherein The particle has a core layer and an outer layer covering the core layer, the scale inhibitor in the core layer is 85% to 100% by weight, and the adhesive is 0 to 15% by weight, the scale inhibitor in the outer layer is 60% to 95% by weight, and the adhesive is 5% to 40% by weight.

5. The scale inhibitor particles of claim 1 or 2, wherein The particle has a core layer, an intermediate layer and an outer layer, the scale inhibitor in the core layer is 95% to 100% by weight, and the adhesive is 0 to 5% by weight, the scale inhibitor in the intermediate layer is 90% to 95% by weight, and the content of the adhesive is 5% to 10% by weight; the scale inhibitor in the outer layer is 80% to 90% by weight, and the adhesive is 10% to 20% by weight.

6. The scale inhibitor particles of claim 5, wherein The thickness of the core layer is 0.5 to 5mm, the thickness of the intermediate layer is 0.5mm to 5mm, and the thickness of the outer layer is 0.5mm to 5mm.

7. A method of preparing the scale inhibitor particles of claim 1, wherein, The method is selected from the following methods: Mixing the scale inhibitor with the water-soluble adhesive, adding the crosslinking agent, and allowing the crosslinking agent to react with the adhesive to fix the scale inhibitor; Mixing the scale inhibitor with the thermosetting adhesive and allowing the thermosetting adhesive to solidify; or Mixing the scale inhibitor, the alcohol-soluble adhesive and the alcohol solvent, and then allowing the alcohol solvent to volatilize.

8. The method of claim 7, wherein, The water-soluble adhesive is selected from polyvinyl alcohol, polyvinyl pyrrolidone and hydroxyethyl cellulose.

9. The method of claim 7, wherein, The crosslinking agent is selected from aldehydes, maleic anhydride and boric acid.

10. The method of claim 7, wherein, The thermosetting adhesive is selected from epoxy resin, polyurethane and phenolic resin.

11. The method of claim 7, wherein, The alcohol-soluble adhesive is selected from ethyl cellulose, rosin resin and dammar resin.

12. The method of claim 7, wherein, The alcohol solvent is ethanol.

13. A water heater, comprising an inner container and a scale inhibitor device arranged in the inner container, wherein the scale inhibitor device contains the scale inhibitor particle according to any one of claims 1 to 6.

14. The water heater according to claim 13, wherein the scale inhibitor particles are spherical with a diameter of 0.5 to 10 mm; each scale inhibitor particle has a weight of 0.1 to 300 mg; and the scale inhibitor device has a packing density of 0.5 to 1.5 g / cm3 in the region where the scale inhibitor particles are contained. 3 .

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