CN108821451B

CN108821451B - Scale inhibitor particles and preparation method thereof

Info

Publication number: CN108821451B
Application number: CN201810742893.5A
Authority: CN
Inventors: 肖国花; 姚振虎; 李水清
Original assignee: AO Smith China Water Heater Co Ltd
Current assignee: AO Smith China Water Heater Co Ltd
Priority date: 2018-07-09
Filing date: 2018-07-09
Publication date: 2024-03-29
Anticipated expiration: 2038-07-09
Also published as: CN108821451A

Abstract

The invention provides a scale inhibitor particle and a preparation method thereof, wherein the scale inhibitor particle comprises a scale inhibitor and a binder, and is characterized in that: the content of the scale inhibitor is 60-98%, the content of the adhesive is 2-40%, the solubility of the scale inhibitor in water below 90 ℃ is lower than 5g/100g, the solubility of the adhesive in water below 90 ℃ after curing is lower than the solubility of the scale inhibitor, the swelling degree of the particles in water below 90 ℃ is lower than 12%, and the hydrolysis degree of the adhesive in water below 90 ℃ after curing is lower than 1%.

Description

Scale inhibitor particles and preparation method thereof

Technical Field

The invention relates to scale inhibitor particles and a preparation method thereof. In particular, the present invention provides a scale inhibitor particle having a stable dissolution rate, which can be used for a long period of time while satisfying the scale inhibiting effect. The invention also relates to a water heater comprising the scale inhibitor particles.

Background

The water quality in different areas is different. Scale may form in use due to the possible calcium magnesium plasma contained in the water. Especially in the water heater field, because the water needs to be heated when using, the incrustation scale is formed more easily. To prevent water scaling, it is often necessary to treat the water with a scale inhibitor. In order to prolong the service time of the scale inhibitor, the scale inhibitor is usually prepared into a block shape or a particle shape together with other components in the prior art. However, the scale inhibitor in the prior art generally has the problems that the scale inhibitor particles or blocks are easy to break, the scale inhibitor is washed away by water, the service life is insufficient, and the like.

Disclosure of Invention

Technical problem

In the prior art, a scale inhibitor containing a scale inhibitor is typically provided before the water heater. Before entering the water heater, tap water is softened by the scale inhibitor, so that the water quality is improved, and the service life of the water heater is prolonged. However, since the scale inhibitor occupies a certain space and affects the interior appearance, it is desired to develop a novel scale inhibitor. The inventors focused on this, and desired to develop a scale inhibitor that can be used outside a water heater and inside the water heater. The above problems can be solved if the scale inhibitor can be used inside the water heater.

However, when the scale inhibitor is used inside the water heater, the following problems are faced. That is, most scale inhibitors are used at normal temperature and rapidly wear at high temperature. Therefore, when used in a water heater, since an electric water heater is generally maintained at a high temperature for a long period of time, it is necessary to use a scale inhibitor capable of being used at a high temperature for a long period of time. In addition, since the scale inhibitor is built in the water heater, the common user is difficult to replace the scale inhibitor by himself, and when the scale inhibitor is exhausted, the scale inhibitor must be replenished by professional maintenance personnel. This requires that the service life of the scale inhibitor must be long to reduce the inconvenience to the user of frequent replenishment of the scale inhibitor.

Secondly, the scale inhibitor particles are placed in the inner container of the water heater, the water storage space of the inner container can be occupied, the longer the scale inhibitor life is, the larger the space of the inner container is occupied, so that the scale inhibitor particles with enough quantity are expected to be filled in a tank body which is as small as possible, but the too large stacking density of the scale inhibitor particles can cause unsmooth water and also affect the scale inhibition effect of the scale inhibitor;

the invention aims to provide a scale inhibitor particle. The purpose is to solve the technical problems. Meanwhile, the scale inhibitor particles can prevent the particles from being broken, so that the scale inhibitor components are prevented from being washed away by water flow. The invention also aims to improve the service life of the scale inhibitor particles. In addition, the invention also provides a scale inhibitor with a specific structure. The scale inhibitor has a specific structure, so that the scale inhibitor can be uniformly released from the scale inhibitor particles, the scale inhibition effect is improved, and the service time is prolonged.

The invention also provides a water heater, a scale inhibitor is arranged in the liner of the water heater, scale inhibitor particles are arranged in the scale inhibitor, parameters such as the shape, the structure, the weight of the scale inhibitor, the weight of an adhesive and the like of the scale inhibitor particles are configured, and the good scale inhibition effect and the service life of the scale inhibitor particles in unit area of the tank body with the scale inhibitor particles are ensured, and the occupied space is small.

Technical proposal

The invention provides a scale inhibitor particle, which comprises a scale inhibitor and a binder, wherein the content of the scale inhibitor is 60% -98%, preferably 60% -95%, the content of the binder is 2% -40%, preferably 5% -40%, the solubility of the scale inhibitor in water below 90 ℃ is lower than 5g/100g, the solubility of the binder in water below 90 ℃ after curing is lower than the solubility of the scale inhibitor, the swelling degree of the particle in water below 90 ℃ is lower than 12%, and the water solubility of the binder in water below 90 ℃ after curing is lower than 1%.

In the scale inhibitor particles of the present invention, the content of the scale inhibitor can be maximized by reducing the content of the binder, thereby prolonging the life of the scale inhibitor particles. However, simply increasing the content of the scale inhibitor results in insufficient strength of the scale inhibitor particles and is liable to break. For this reason, the inventors found that by selecting a scale inhibitor having a solubility of less than 5g/100g of water and allowing the solubility of the binder to be further lower than that of the scale inhibitor while controlling the swelling degree of the scale inhibitor particles to be less than 12% in water at 90 ℃ or less and selecting a binder having a hydrolysis degree of less than 1% in water at 90 ℃ or less after curing, the binder can be made to remain in its skeleton structure when the scale inhibitor is dissolved, thereby prolonging the service time of the scale inhibitor particles.

The inventors have also found that when a scale inhibitor having a specific polar group is used, it is possible to interact with the binder, and suppress the expansion rate of the scale inhibitor particles, thereby solving the technical problem of the present invention better. The scale inhibitor may contain at least one of the following polar groups or salts thereof: phosphate, phosphonate, phosphate, phosphoryl, carboxyl and sulfonate groups. The scale inhibitor is preferably a polyphosphate, an organic phosphonate, maleic anhydride and polyaspartic acid.

In addition, the invention also provides a preparation method of the scale inhibitor particles and the scale inhibitor particles with specific structures.

The scale inhibitor particles of the present invention may consist of only the scale inhibitor and the binder. The scale inhibitor particles of the present invention may contain other additives without affecting the technical effects of the present invention.

In order to improve the service life of the scale inhibitor particles, in the scale inhibitor particles of the invention, the proportion of the scale inhibitor to the adhesive agent is reduced from the center to the outer surface in a gradient manner. By this structure, the scale inhibitor content is small on the outer surface of the scale inhibitor particles, but the area of the scale inhibitor in contact with water is large. As the scale inhibitor dissolves out, the scale inhibitor particles become smaller, the contact area of the scale inhibitor with water becomes smaller, but the content of the scale inhibitor increases, thereby compensating for the decrease in dissolution rate caused by the decrease in the contact area of the scale inhibitor with water. Through the structure, the scale inhibitor can be dissolved out at a uniform rate, and the scale inhibition effect and the service life of the scale inhibitor particles are ensured.

As a specific example, the scale inhibitor particles may have a core layer, an intermediate layer and an outer layer, the scale inhibitor of the core layer being 95 to 100 wt%, the binder being 0 to 5 wt%, the scale inhibitor of the intermediate layer being 90 to 95 wt%, the content of the binder: 5 to 10 wt%; the scale inhibitor of the outer layer is 80-90 wt% and the binder is 10-20 wt%.

The invention also provides a water heater which comprises an inner container and a scale inhibitor arranged in the inner container, wherein the scale inhibitor particles are arranged in the scale inhibitor.

Technical effects

The scale inhibitor particles can play a role in long-term slow release, and can still ensure that the particle skeleton is not broken in the process of dissolving the scale inhibitor. In particular, the scale inhibitor particles of the present invention can be used for a long period of time while satisfying the scale inhibiting effect even when used in hot water.

Drawings

FIG. 1 is a photograph of pure pieces of calcium citrate scale inhibitor at the beginning of soaking in water at room temperature (25 ℃), 40℃and 90℃respectively;

FIG. 2 is a photograph of the scale inhibitor particles of example 1 after soaking in water at room temperature (25 ℃), 40℃and 90℃for 24 hours, respectively;

FIG. 3 is a photograph of a block of pure scale inhibitor before and after 5 tons of water, respectively;

FIG. 4 is a photograph of the scale inhibitor particles of example 1 before and after 5 tons of water;

FIG. 5 is a schematic structural view of the scale inhibitor particles of example 5 of the present invention;

FIG. 6 is a schematic diagram of a water heater liner according to the present invention.

Detailed Description

The following describes the invention in further detail with reference to specific examples.

The scale inhibitor particle is prepared from the following components in percentage by weight by adopting a self-sparingly-soluble scale inhibitor: 60% -98% of scale inhibitor, preferably 60% -95% of binder: 40% -2%, preferably 5% -40%. Wherein the scale inhibitor is one or more of slightly soluble scale inhibitors such as calcium citrate, ethylene Diamine Tetra Methylene Phosphonic Acid (EDTMPA) and the like; the adhesive is at least one of epoxy resin, polyacrylate, polyurethane, polyvinyl alcohol and a curing agent thereof.

The invention also provides a preparation method of the scale inhibitor. The scale inhibitor particles can be formed by adopting a roll forming method, an extrusion and polishing method, a screw extrusion method and an isostatic pressing method. The roll forming preparation steps comprise: and mixing the scale inhibitor, the adhesive and the water in the proportion, and then adding the mixture into a ball rolling machine to prepare the mother ball. After the preparation of the mother balls is finished, the mother balls are placed in a ball rolling machine, then the adhesive and water are sprayed into the ball rolling machine, then powder is added, the reciprocation is carried out, the preparation is stopped until the mother balls grow to the required size, and then the mother balls are dried in an oven at 60-100 ℃ for 4-12 hours, so that the scale inhibitor particles are obtained. The screw extrusion method is to knead the above mixed sample in a kneader and mix it uniformly. And then preparing a sample by adopting a screw extruder, and drying in an oven at 60-100 ℃ for 4-12 hours to obtain the scale inhibitor particles.

The invention adopts the self-slightly soluble scale inhibitor to compound with the curable adhesive, so that the scale inhibitor particles can stably exist in the water treatment process, and the scale inhibitor particles cannot be dispersed due to excessive dissolution of the adhesive and the scale inhibitor, so that the long service life cannot be realized.

As shown in fig. 6, the inner container 10 of the water heater of the present invention includes a scale inhibitor 20 disposed therein; the scale inhibitor 20 contains a quantity of scale inhibitor particles. The weight of each scale inhibitor particle is 0.1-300mg; the bulk density of the unit volume of the area where the scale inhibitor is provided with the scale group agent particles is 0.5-1.5g/cm ³ Within the range. The scale inhibitor particles are preferably spherical with a diameter of 0.5-10 mm.

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 comprising a scale inhibitor and a binder, the scale inhibitor having an increasing weight-to-weight gradient and the binder having a decreasing weight-to-weight gradient; the surface area of each scale inhibitor particle is from large to small from beginning to ending, if the content of the scale inhibitor from the outer layer to the core layer is consistent, the longer the time is, the smaller the content of the scale inhibitor is, and the scale inhibition effect of different time periods is reduced.

Preferably, the scale inhibitor further comprises an intermediate layer positioned between the core layer and the outer layer, wherein the thickness of the core layer is 0.5-5mm, the thickness of the intermediate layer is 0.5-5mm, and the thickness of the outer layer is 0.5-5 mm.

The adhesive in the scale inhibitor particles preferably has a framework structure, and after the scale inhibitor in the scale inhibitor particles is consumed, the adhesive can still remain in the scale inhibition device to avoid polluting water in the liner.

The scale inhibitor particles are placed in the inner container of the water heater, the water storage space of the inner container is occupied, the longer the scale inhibitor life is, the larger the space of the inner container is occupied, and therefore, the sufficient scale inhibitor particles are desirably filled in the tank body which is as small as possible. However, too large a packing density of the scale inhibitor particles can cause unsmooth water passing and also affect the scale inhibition effect of the scale inhibitor; the scale inhibitor particles are configured in shape, structure, weight of the scale inhibitor, weight of the adhesive and other parameters, so that the scale inhibitor particles in unit area in the scale inhibitor device have better scale inhibition effect, have longer service life and occupy less space.

The shape, structure, weight of the scale inhibitor, weight of the adhesive and other parameters of the scale inhibitor particles are designed, so that the scale inhibitor particles in the unit area of the area where the scale inhibitor particles are filled in the tank body have better scale inhibition effect and service life, and occupy less space.

Examples

Swelling degree test method

The swelling degree of the scale inhibitor particles under water at different temperatures was tested according to the swelling balance method. 5g of filter material are weighed, placed in 100ml of water respectively, and placed at different temperatures for standing. The scale inhibitor particles absorb water during immersion in water. The volume change of the scale inhibitor particles before and after water absorption (V0 before water absorption, V1 after water absorption) was measured until after water absorption equilibrium. The degree of swelling is denoted by Q:

Q＝(V1-V0)/V0*100％

for the bar sample, the swelling degree can be confirmed by directly using the diameter change (diameter D0 before water absorption and D1 after water absorption). The degree of swelling is denoted by Q:

Q＝(D1-D0)/D0*100％

hydrolysis degree testing method

The degree of hydrolysis was tested by the weightlessness method. The adhesive is solidified independently according to the required proportion and is not mixed with the powder. Weighing a certain weight of adhesive after curing to be m1, soaking in certain water at 90 ℃, taking out, drying and weighing after a certain period of time until the weight is unchanged, and calculating the degree of hydrolysis according to the following formula when the experiment is ended and the weight is recorded as m 2:

hydrolysis degree= (m 1-m 2)/m 1 × 100%

Dissolution rate test method

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

Water dissolution scale inhibition life test method

And placing 100g of sample in a 10-inch filter flask, starting a water passing experiment, using the flow rate of 5L/Min to pass water, and testing the weight loss rate and the static scale inhibition effect after 20 tons and 40 tons of water pass through to confirm the service life of the filter material.

Example 1

The scale inhibitor granule adopts calcium citrate as scale inhibitor, and the adhesive is AB type epoxy resin (model: letai 7255, henkel company). Scale inhibitor: adhesive = 9:1, adding a certain amount of water and a scale inhibitor: water = 1.5:1, preparing a strip-shaped particle sample by adopting a screw extrusion mode, wherein the diameter of the sample is 1.5mm, and the length of the sample is 3-5mm. The solubility of calcium citrate in water at 25 ℃ is 0.1g/100g, slightly soluble in water. The samples were tested for swelling and hydrolysis at various temperatures and the test results are shown in table 1. The dissolution of the scale inhibitor particles at different temperatures is shown in figures 1 and 2. FIG. 1 is a photograph of pure blocks of calcium citrate scale inhibitor at the beginning of soaking in water at room temperature (25 ℃), 40℃and 90℃respectively. As can be seen from fig. 1, a significant dissolution of the pure calcium citrate cake occurred. FIG. 2 is a photograph of the scale inhibitor particles of example 1 after soaking in water at room temperature (25 ℃), 40℃and 90℃for 24 hours, respectively. Compared with fig. 1, it can be seen that the scale inhibitor particles of the present application can stably exist in an aqueous solution, so that the waste of the scale inhibitor can be reduced.

The stability of the scale inhibitor particles at different temperatures was also tested while immersed. Table 1 shows the swelling ratios of the scale inhibitor particles of example 1 after soaking in water at room temperature (25 ℃), 40℃and 90℃for 12 hours and 24 hours, respectively.

TABLE 1 swelling Rate of Scale inhibitor particles of example 1 at different temperatures and different times

Temperature (. Degree. 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

The inventor also tests the adhesive, namely confirms that the adhesive can stably exist in water at different temperatures, so that the scale inhibitor is well fixed and cannot be washed away.

The test method is as follows: mixing and crosslinking the epoxy resin A component and the epoxy resin B component, weighing 1g of crosslinked samples, placing the samples in a beaker, injecting 200ml of water, then placing the samples in warm water (namely 25 ℃ water), 40 ℃ water and 90 ℃ water respectively, standing for 24 hours, drying and weighing, and metering the weight of the adhesive, wherein the statistical result is shown in table 2:

TABLE 2 degree of hydrolysis of the adhesive after curing at various temperatures

Temperature (. Degree. C.)	Initial weight (g)	Weight after 24h (g)	Degree of hydrolysis (%)
				25	1.0051	1.0048	0.03
40	1.0032	1.0031	0.01
				90	1.0029	1.0027	0.02

It can be seen that the adhesive is stably present in water after being crosslinked by the AB component, and does not hydrolyze with immersion in water, thereby more stably maintaining the shape and performance of the particles.

The inventors have also tested the dissolution rates of the calcium citrate powder and the scale inhibitor particles of example 1, and the test results are shown in table 3. As is clear from Table 3, the scale inhibitor particles of example 1 were stable and did not excessively leach out.

TABLE 3 comparison of dissolution rates of Scale inhibitor particles and pure scale inhibitor

Sample name	Block scale inhibitor	Scale inhibitor particles
			Solubility (g/100 g) for 30min	0.055	0.03
Solubility (g/100 g) for 24h	0.065	0.03

The inventors have studied not only the granular state of the scale inhibitor in the stationary state but also the elution life in the water passing state.

Fig. 3 is a photograph of a block of pure scale inhibitor before and after 5 tons of water, respectively. Weighing 10g of each block scale inhibitor and 10g of each granular scale inhibitor respectively, and carrying out water passing experiments. With the extension of the water passing time, the amount of the blocky scale inhibitor is greatly reduced, and only a small amount of the blocky scale inhibitor is remained finally.

FIG. 4 is a photograph of the scale inhibitor particles of example 1 before and after 5 tons of water. As can be seen from fig. 4, the scale inhibitor particles of example 1 still remained very intact and had a good morphology after 5 tons of water.

To better characterize its lifetime, the inventors also weighed the sample after 5 tons of water, with the following results:

after 5 tons of the massive scale inhibitor is washed by water, the weight is 1.53g, and the weight loss is 84.7%; the scale inhibitor particles of example 1, however, weighed 5.89g after 5 tons of water, and had a weight loss of 41.1%. Thus, the scale inhibitor particles of example 1 can have more than twice the life of the bulk pure scale inhibitor.

Example 2

The scale inhibitor particles are prepared from ethylene diamine tetramethylene phosphonic acid (EDTMPA) as a scale inhibitor. EDTMPA is white crystalline powder with melting point of 215-217 ℃ and slightly soluble in water at room temperature, and the solubility is less than 5% at room temperature. The scale inhibitor has strong capability of chelating metal ions, can well prevent the generation of scale, and has strong water absorption. The adhesive was an AB type epoxy resin (model number of Hakka, ltd.) and was used as a resin. Scale inhibitor: adhesive = 9:1, and adding certain amount of water to make the scale inhibitor: water = 1.5:1. and preparing a spherical particle sample by adopting a roll forming mode, wherein the diameter of the sample is about 3-4 mm. The scale inhibitor particles of example 2 were tested for swelling and hydrolysis at various temperatures and the test results are shown in table 4.

Example 3

The scale inhibitor particles are prepared from calcium citrate serving as a scale inhibitor. The adhesive was an AB type epoxy resin (model number of Hakka, ltd.) and was used as a resin. Scale inhibitor: adhesive = 7:3, adding a certain amount of water to enable the scale inhibitor to be: water = 1.5:1. and preparing a spherical particle sample by adopting a roll forming mode, wherein the diameter of the sample is about 3-4 mm. The scale inhibitor particles of example 3 were tested for swelling and hydrolysis at various temperatures and the test results are shown in table 4.

Example 4

EDTMPA is selected as the scale inhibitor in the scale inhibitor particles. The selected adhesive is polyvinyl alcohol, the required curing agent is synchronously mixed, and a certain amount of water is added for mixing. The selected proportion is as follows: scale inhibitor: adhesive = 7:3, adding a certain amount of water and a scale inhibitor: water = 1.5:1, preparing a spherical particle sample by adopting a rolling ball method, wherein the diameter of the sample is 1.5mm. The scale inhibitor particles of example 2 were tested for swelling and hydrolysis at various temperatures and the test results are shown in table 4.

Example 5

The scale inhibitor particles were produced using the scale inhibitor and the binder in example 1, except that they were produced as scale inhibitor particles having a multilayer structure as shown in fig. 5. The particle has a core layer 3, an intermediate layer 2 and an outer layer 1, wherein the scale inhibitor of the core layer 3 is 96 weight percent, the binder is 4 weight percent and the thickness is 2mm; the scale inhibitor of the middle layer 2 is 90 weight percent, the content of the adhesive is 10 weight percent, and the thickness is 2mm; the scale inhibitor of the outer layer 1 is 85% by weight, the binder is 15% by weight, and the thickness is 2mm. The particles are prepared by a method of preparing the core layer 3, then preparing the intermediate layer 2 and finally preparing the outer layer 1. Compared with the scale inhibitor particles in the embodiment 1, the scale inhibitor particles in the embodiment 5 have more uniform release, and the weight loss after 5 tons of water is 39.0%, so that the service life of the scale inhibitor can be further prolonged. When the scale inhibitor particles are placed in a scale inhibition tank in a water heater liner, a good scale inhibition effect can be still maintained when the scale inhibitor particles are used in the water heater, and the weight loss is 41.2% after 5 tons of water passes through the water heater at 70 ℃.

From the above table, when the solubility of the scale inhibitor in water below 90 ℃ is lower than 0.1g/100g, the solubility of the adhesive in water below 90 ℃ after curing is lower than the solubility of the scale inhibitor, the swelling degree of the particles in water below 90 ℃ is lower than 12%, and the hydrolysis degree of the adhesive in water below 90 ℃ after curing is lower than 1%, the weight loss of the scale inhibitor after 5 tons of water is smaller, and the service life is longer.

In the above experiments, the scale inhibitor was used in an amount of 10g, which may provide a scale inhibiting effect for about 10 tons of water. The water consumption of the water heater is about 30-50 tons for the common users. If 100g of the scale inhibitor of the present invention is used, a scale inhibiting effect can be provided for about 100 tons of water. Therefore, the scale inhibitor of the invention can be used for more than about 2 years, and the frequency of supplementing the scale inhibitor is greatly reduced.

Claims

1. A scale inhibitor particle for a water heater, the scale inhibitor particle comprising a scale inhibitor and a binder, characterized in that: the content of the scale inhibitor is 60-98%, the content of the adhesive is 2-40%, the solubility of the scale inhibitor in 90 ℃ water is lower than 5g/100g, the solubility of the adhesive in 90 ℃ water after curing is lower than the solubility of the scale inhibitor, the swelling degree of the particles in 90 ℃ water is lower than 12%, the hydrolysis degree of the adhesive in 90 ℃ water after curing is lower than 1%,

the scale inhibitor is at least one of the following scale inhibitors: citrate, polyphosphate and organophosphonate,

the adhesive has a skeletal structure.

2. The scale inhibitor particles of claim 1, wherein in the particles, the weight of the scale inhibitor increases in a gradient from the outer surface to the center, and the weight of the binder decreases in a gradient.

3. The scale inhibitor particle of claim 1 or 2, wherein the particle has a core layer and an outer layer coating the core layer, the scale inhibitor of the core layer being 85 to 100 wt%, the binder being 0 to 15 wt%, the scale inhibitor of the outer layer being 60 to 95 wt%, the binder being 5 to 40 wt%.

4. The scale inhibitor particles of claim 1 or 2, wherein the particles have a core layer, an intermediate layer and an outer layer, the scale inhibitor of the core layer being 95 to 100 wt%, the binder being 0 to 5 wt%, the scale inhibitor of the intermediate layer being 90 to 95 wt%, the binder being present in an amount of: 5 to 10 wt%; the scale inhibitor of the outer layer is 80-90 wt% and the binder is 10-20 wt%.

5. The scale inhibitor particles of claim 4, wherein the core layer has a thickness of 0.5mm to 5mm, the intermediate layer has a thickness of 0.5mm to 5mm, and the outer layer has a thickness of 0.5mm to 5mm.

6. A process for the preparation of the scale inhibitor particles of claim 1, wherein the process is selected from the group consisting of:

mixing the scale inhibitor with the water-soluble adhesive, adding the cross-linking agent, enabling the cross-linking agent to react with the adhesive, and fixing the scale composition agent;

mixing a scale inhibitor with a thermosetting adhesive and curing; or (b)

The scale inhibitor, the alcohol-soluble adhesive and the alcohol solvent are mixed and then the alcohol solvent is volatilized.

7. The method of claim 6, wherein the water-soluble binder is selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, and hydroxyethylcellulose.

8. The method of claim 6, wherein the cross-linking agent is selected from the group consisting of aldehydes, maleic anhydride, and boric acid.

9. The method of claim 6, wherein the thermosetting adhesive is selected from the group consisting of epoxy, polyurethane, and phenolic.

10. The method of claim 6, wherein the alcohol-soluble binder is selected from the group consisting of ethylcellulose, rosin resins, and dammar resins.

11. The method of claim 6, wherein the alcoholic solvent is ethanol.

12. A water heater comprising a liner and a scale inhibitor disposed in the liner, the scale inhibitor containing the scale inhibitor particles of any one of claims 1-5.

13. The water heater as claimed in claim 12, wherein the scale inhibitor particles are spherical with a diameter of 0.5-10 mm; the weight of each scale inhibitor particle is 0.1-300mg, and the bulk density per unit volume in the area filled with the scale inhibitor particles in the scale inhibition device is 0.5-1.5g/cm ³ 。