A blowdown stabilizer for a boiler feedwater system

Abstract

The application relates to a blowdown stabilizer for a boiler feedwater system. The blowdown stabilizer comprises dodecahydrodiphenylamine, triethylamine, morpholine, ethanolamine, aminopropionic acid, hydrazine hydrate, acetaldoxime, N,N-diethylhydroxylamine and desalted water; wherein, calculated in parts by weight, the dodecahydrodiphenylamine is 15-25 parts, the triethylamine is 10-30 parts, the morpholine is 10-25 parts, the ethanolamine is 5-10 parts, the aminopropionic acid is 4-5 parts, the hydrazine hydrate is 2-5 parts, the acetaldoxime is 5-15 parts, the N,N-diethylhydroxylamine is 10-20 parts and the desalted water is 5-20 parts; and the preparation method of the blowdown stabilizer is as follows: firstly, desalted water is added into a first reaction kettle, then the dodecahydrodiphenylamine, the morpholine, the N,N-diethylhydroxylamine and the triethylamine are sequentially added into the first reaction kettle to form a first mixed solution, the first mixed solution is stirred for 30 minutes, and the temperature of the first reaction kettle is 50 DEG C.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of boiler feed water treatment, and more particularly, to a blowdown stabilizer for a boiler feed water system. BACKGROUND

[0002] The synthetic ammonia waste heat boiler belongs to a special pressure equipment boiler, the boiler feed water is supplemented by synthetic process condensate and methanol process condensate, and the insufficient part is supplemented by refined water, oxygen is removed through a deoxidizing tank, and then the feed water pump is used to extract the water into a boiler drum through an economizer. The wet steam is separated from the steam in the drum, and the qualified superheated steam is generated by the secondary superheating to input the main steam pipe network. The main steam pipe network is mainly used for steam purging during start-up and pressure steam pipe network balancing during normal start-up, and can also be used as a fan turbine driving power.

[0003] In order to ensure the safe operation of the synthetic ammonia boiler feed water, the water quality needs to be strictly controlled.

[0004] At present, the method for controlling the water quality is to add ammonia water and amines to the boiler feed water system. However, if the addition of the reagents is not properly controlled, corrosion and salt deposition are prone to occur. The corrosion factors such as oxygen, chlorine ions and hydrogen ions enter the metal surface through the scale gap, which leads to an increase in the boiler slag, sludge and sediment, and affects the boiler water quality. Moreover, the corrosion rate of the boiler body increases in a geometric ratio, and in severe cases, the over-economizer corrosion leakage safety accident occurs, which leads to shutdown and causes immeasurable economic losses.

[0005] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. SUMMARY

[0006] An object of the present application is to provide a new technical solution of a blowdown stabilizer for a boiler feed water system.

[0007] According to a first aspect of the present application, a blowdown stabilizer for a boiler feed water system is provided. The blowdown stabilizer comprises dodecahydrodiphenylamine, triethylamine, morpholine, ethanolamine, aminopropionic acid, hydrazine hydrate, acetaldoxime, N,N-diethylhydroxylamine and desalted water; wherein, calculated by weight fraction, the dodecahydrodiphenylamine is 15-25 parts, the triethylamine is 10-30 parts, the morpholine is 10-25 parts, the ethanolamine is 5-10 parts, the aminopropionic acid is 4-5 parts, the hydrazine hydrate is 2-5 parts, the acetaldoxime is 5-15 parts, the N,N-diethylhydroxylamine is 10-20 parts and the desalted water is 5-20 parts; and

[0008] The preparation method of the sewage stabilizer is: first, adding desalted water into a first reaction kettle, then adding the dodecahydrodiphenylamine, the morpholine, the N,N-diethylhydroxylamine and the triethylamine into the first reaction kettle in sequence to form a first mixed solution, stirring the first mixed solution for 30 minutes, and the temperature of the first reaction kettle is 50 DEG C; then, adding acetaldoxime, ethanolamine, hydrazine hydrate and aminopropionic acid into a second reaction kettle to form a second mixed solution, sealing the second reaction kettle, stirring the second mixed solution for 40 minutes, and then standing, and the temperature of the second reaction kettle is 30 DEG C; finally, mixing the first mixed solution and the second mixed solution in a third reaction kettle, stirring for 70 minutes, standing for 1 hour, and the temperature of the third reaction kettle is 40 DEG C; wherein, the material of the first reaction kettle is 304 stainless steel, the material of the second reaction kettle is glass steel, and the material of the third reaction kettle is glass steel;

[0009] The phenothiazine alkalinity of the solution of the sewage stabilizer diluted by 100 times of desalted water is greater than or equal to 200 mg / L, the density at 25 DEG C is 0.9 g / cm 3 -1.0 g / cm 3 .

[0010] Optionally, the dodecahydrodiphenylamine is 20 parts by weight.

[0011] Optionally, the triethylamine is 12-18 parts by weight.

[0012] Optionally, the ethanolamine is 6-8 parts by weight.

[0013] Optionally, the morpholine is 14-16 parts by weight.

[0014] Optionally, the hydrazine hydrate is 3-4 parts by weight.

[0015] Optionally, the acetaldoxime is 8-13 parts by weight.

[0016] Optionally, the acetaldoxime is 10 parts by weight.

[0017] Optionally, the ethanolamine is 9 parts by weight, the aminopropionic acid is 5 parts by weight, and the hydrazine hydrate is 4 parts by weight.

[0018] Optionally, the N,N-diethylhydroxylamine is 15 parts by weight.

[0019] The stable agent for blowdown is suitable for the feed water system of the ammonia boiler in the embodiment of the present application. The stable agent for blowdown has excellent neutralization of carbonic acid and stability of PH value, and has oxygen removal function, pre-film function and the like by adding dodecahydrodiphenylamine, triethylamine, morpholine, ethanolamine, aminopropionic acid, hydrazine hydrate, acetaldoxime and N,N-diethylhydroxylamine. The stable agent for blowdown can significantly reduce the blowdown rate of the boiler and improve the water vapor quality of the boiler. By adding the stable agent for blowdown in the feed water system of the boiler, the corrosion of the surface of the boiler can be reduced, and the safe operation effect can be effectively improved.

[0020] Other features of the present application, its nature and advantages will become apparent from the accompanying detailed description of the exemplary embodiments of the application, taken with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0022] Figure 1 is a preparation method flow chart of the stable agent according to the embodiment of the present application. DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments are not limitations on the scope of the present application unless otherwise specifically stated.

[0024] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting on the scope of the application or its applications or uses.

[0025] Techniques and equipment known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification where appropriate.

[0026] In all of the examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0027] It should be noted that like reference numerals and letters refer to like items in the several views of the drawings, and as such, further discussion of such items is not necessary where the items have already been discussed in relation to one of the drawings.

[0028] According to one embodiment of the present application, a kind of blowdown stabilizer for boiler feedwater system is provided, including twelve hydrogen diphenylamine, triethylamine, morpholine, ethanolamine, amino propionic acid, hydrazine hydrate, acetaldoxime, N,N-diethylhydroxylamine and desalted water;Wherein, by weight fraction calculation, the twelve hydrogen diphenylamine 15-25 parts, the triethylamine 10-30 parts, the morpholine 10-25 parts, the ethanolamine 5-10 parts, the amino propionic acid 4-5 parts, the hydrazine hydrate 2-5 parts, the acetaldoxime 5-15 parts, the N,N-diethylhydroxylamine 10-20 parts and the desalted water 5-20 parts;And

[0029] The preparation method of the blowdown stabilizer is: first, desalted water is added to a first reaction kettle, then the twelve hydrogen diphenylamine, the morpholine, the N,N-diethylhydroxylamine and the triethylamine are sequentially added to the first reaction kettle to form a first mixed solution, the first mixed solution is stirred for 30 minutes, and the temperature of the first reaction kettle is 50 DEG C;Then, acetaldoxime, ethanolamine, hydrazine hydrate and amino propionic acid are added to a second reaction kettle to form a second mixed solution, the second reaction kettle is sealed, the second mixed solution is stirred for 40 minutes, and then is left to stand, and the temperature of the second reaction kettle is 30 DEG C;Finally, the first mixed solution and the second mixed solution are mixed in a third reaction kettle, stirred for 70 minutes, left to stand for 1 hour, and the temperature of the third reaction kettle is 40 DEG C;Wherein, the material of the first reaction kettle is 304 stainless steel;The material of the second reaction kettle is glass steel;The material of the third reaction kettle is glass steel;

[0030] The phenothiazine alkalinity of the solution of the blowdown stabilizer diluted by 100 times with desalted water is greater than or equal to 200 mg / L, the density at 25 DEG C is 0.9 g / cm 3 -1.0 g / cm 3 .

[0031] In this example, the twelve hydrogen diphenylamine has an aromatic structure, can be adsorbed on the surface of the boiler wall and form a protective film, thereby playing a corrosion inhibition role. In addition, the twelve hydrogen diphenylamine has redox properties and can participate in the redox reaction in the boiler water, thereby adjusting the water quality.

[0032] Morpholine is an alkaline compound and is alkaline after dissolving in water. In boiler water treatment, morpholine can be used as a pH regulator to neutralize acidic substances in water and increase the pH value, thereby slowing down acidic corrosion. In addition, morpholine may also have a corrosion inhibition effect by forming a protective film on the surface of the boiler wall to prevent corrosion.

[0033] N,N-diethylhydroxylamine has corrosion inhibition and redox effects, and can prevent metal corrosion in boiler water. N,N-diethylhydroxylamine can form a protective film on the surface of the boiler wall by adsorption, or adjust water quality by participating in redox reactions.

[0034] Triethylamine is an organic base. Triethylamine can be used to adjust the pH of the boiler water to inhibit acid corrosion. In addition, triethylamine can also react with certain anions in the boiler water (such as sulfate ions, carbonate ions, etc.) to form precipitates, thereby removing these anions and reducing the risk of fouling and corrosion.

[0035] Acetaldoxime is a reducing agent that can be used to remove oxidizing agents in the boiler water to prevent oxidation corrosion. In addition, acetaldoxime can also be used as a pH adjuster to adjust the acidity and alkalinity of the boiler water.

[0036] Ethanolamine is an organic amine with corrosion inhibition and chelation effects. Ethanolamine can form stable complexes with metal ions (such as calcium ions, magnesium ions, etc.) to prevent metal ions from causing fouling and corrosion in the boiler water. In addition, ethanolamine can also be used as a pH adjuster to adjust the acidity and alkalinity of the boiler water.

[0037] Hydrazine hydrate is a strong reducing agent that can be used to remove oxidizing agents in the boiler water to prevent oxidation corrosion. In addition, hydrazine hydrate can also be used as a deoxidizer to remove dissolved oxygen in the boiler water, further preventing oxidation corrosion. Hydrazine hydrate can also be used to adjust the pH of the boiler water.

[0038] Amino propionic acid is an amino acid with chelation and corrosion inhibition effects. Amino propionic acid can form stable complexes with metal ions to prevent metal ions from causing fouling and corrosion in the boiler water. In addition, amino propionic acid can also be used as a pH adjuster to adjust the acidity and alkalinity of the boiler water.

[0039] As shown in Figure 1 The preparation method of the blowdown stabilizer is as follows:

[0040] First, desalted water is added to the first reaction kettle, and then the dodecahydrodiphenylamine, morpholine, N,N-diethylhydroxylamine, and triethylamine are sequentially added to the first reaction kettle to form a first mixed solution. The first mixed solution is stirred for 30 minutes, and the temperature of the first reaction kettle is 50°C.

[0041] Then, acetaldoxime, ethanolamine, hydrazine hydrate, and amino propionic acid are added to the second reaction kettle to form a second mixed solution. The second reaction kettle is sealed, and the second mixed solution is stirred for 40 minutes and then left to stand. The temperature of the second reaction kettle is 30°C.

[0042] Finally, the first mixture and the second mixture are mixed in a third reactor, stirred for 70 minutes, and left to stand for 1 hour, and the temperature of the third reactor is 40℃.

[0043] The material of the first reactor is 304 stainless steel; the material of the second reactor is glass fiber reinforced plastic; and the material of the third reactor is glass fiber reinforced plastic.

[0044] The first mixture contains triethylamine. Triethylamine is an organic compound, which is colorless, has a strong ammonia smell, and is extremely volatile, and can be dissolved in water and various organic solvents. Different types of stainless steel have different corrosion resistance to triethylamine. For example, stainless steel with high nickel content (such as 316L) will corrode in the presence of triethylamine. Low-nickel stainless steel, such as 304 stainless steel, has relatively good corrosion resistance and is not prone to corrosion in the presence of triethylamine. Moreover, 304 stainless steel has good high-temperature resistance and good durability, and can be used at 50℃ for a long time.

[0045] Acetaldoxime and ethanolamine can corrode stainless steel, but not glass fiber reinforced plastic, so the second reactor and the third reactor are both made of glass fiber reinforced plastic. Glass fiber reinforced plastic will not be corroded by dodecahydrodiphenylamine, triethylamine, morpholine, ethanolamine, aminopropionic acid, hydrazine hydrate, acetaldoxime, and N,N-diethylhydroxylamine, and can maintain good physical and chemical properties at 30℃ to 40℃. Glass fiber reinforced plastic has low cost and is easy to process and prepare.

[0046] The blowdown stabilizer has strong chemical stability and is non-flammable, non-explosive, and non-toxic under normal conditions. When the quality of the feed water (or make-up water) is stable, it can ensure that various water vapor operation indicators are stable and meet the standards for a long time.

[0047] Dodecahydrodiphenylamine, morpholine, N,N-diethylhydroxylamine, and triethylamine have similar properties, are alkaline, and are used as corrosion inhibitors, so they are sequentially added to the first reactor for mixing, which can effectively avoid the violent heat release between different substances. Acetaldoxime, ethanolamine, and hydrazine hydrate are all alkaline and are used to adjust the pH value and remove oxygen of the boiler water, so they are sequentially added to the second reactor to avoid violent heat release during mixing. Aminopropionic acid is acidic as a whole, and the addition of aminopropionic acid at the end can adjust the pH of the blowdown stabilizer by controlling the amount of aminopropionic acid added. The blowdown stabilizer has strong alkalinity, and direct measurement of the alkalinity of the blowdown stabilizer will cause a large error. The phenothiazine alkalinity of the solution of the blowdown stabilizer diluted 100 times with desalted water is greater than or equal to 200mg / L. This way can improve the calculation accuracy of the alkalinity of the pollution stabilizer. In this range of alkalinity, the pollution stabilizer can react with the hardness components such as calcium and magnesium in water to form water slag or precipitate, thereby preventing these components from forming scale on the boiler heating surface, and effectively avoiding the corrosion of the boiler water to the boiler. In this range of alkalinity, the chelation in the pollution stabilizer is significant, which can effectively avoid the scaling of hardness components such as calcium and magnesium ions in the boiler water in the boiler. In addition, when the alkalinity of the boiler water is too high, it will react with oxygen to form oxides or precipitates, which is easy to scale in the boiler. On the contrary, when the alkalinity of the boiler water is too low, the oxygen content may increase, increasing the risk of corrosion of the boiler heating surface. In this range of alkalinity, the boiler is not easy to scale and corrode.

[0048] In the embodiments of the present application, the pollution stabilizer is suitable for the feedwater system of the ammonia boiler. The pollution stabilizer has excellent neutralization of carbonic acid and PH value stabilization performance, and has oxygen removal function, pre-film function, etc. by adding dodecahydrodiphenylamine, triethylamine, morpholine, ethanolamine, aminopropionic acid, hydrazine hydrate, acetaldoxime and N,N-diethylhydroxylamine. The pollution stabilizer significantly reduces the blowdown rate of the boiler, and the water vapor quality of the boiler is good. By adding the pollution stabilizer in the feedwater system of the boiler, the corrosion of the boiler surface can be reduced, and the safe operation effect can be effectively improved.

[0049] Preferably, the dosage of the pollution stabilizer in the boiler water is 3-20 ppm. In this range, the pollution stabilizer is released slowly, and the scale inhibition effect is good. The medicament component in the boiler water is low, and it is not easy to form precipitates, which will not cause the boiler to scale and corrode, further reducing the blowdown rate of the boiler.

[0050] In one example, the dodecahydrodiphenylamine is 20 parts by weight.

[0051] The synthesis method of dodecahydrodiphenylamine is to use aniline as raw material, and to be prepared by high-temperature and high-pressure hydrogenation under the action of a catalyst. Dodecahydrodiphenylamine can be used as an organic synthesis intermediate for corrosion inhibitors, gas phase corrosion inhibitors, etc. The content of this component in the medicament is 17-23 parts by weight, preferably 20 parts.

[0052] In one example, the triethylamine is 12-18 parts by weight.

[0053] Triethylamine is an organic compound that can be dissolved in water, ethanol and most organic solvents. It is mainly used for corrosion inhibitors and reacts quickly with corrosive substances. The content of this component in the medicament is 10-30 parts by weight, preferably 12-18 parts,

[0054] In one example, the ethanolamine is 6-8 parts by weight.

[0055] In this example, ethanolamine is in the range to make the chelation of the scale stabilizer good, which can effectively prevent the scale and corrosion in the boiler.

[0056] In one example, the morpholine is 14-16 parts by weight.

[0057] The production method of morpholine can adopt DEG method. The DEG method mainly uses diethylene glycol as raw material to obtain morpholine under the action of a catalyst at a certain temperature and pressure by catalytic distillation. Morpholine can be used as an inhibitor and a passivator for steam boilers, and is suitable for complex and harsh water quality. The content of this component in the agent is 10-25 parts by weight, preferably 14-16 parts.

[0058] In one example, the morpholine is 15 parts.

[0059] In the preparation method of the embodiment of the present application, the morpholine is 15 parts by weight.

[0060] Of course, the above-mentioned components in the embodiment of the present application are not limited to the above-mentioned preparation method, and those skilled in the art can set them according to actual needs. For example, morpholine can also be produced by the DEA production method.

[0061] In one example, the acetaldoxime is 8-13 parts by weight.

[0062] Acetaldoxime is a new type of oxygen scavenger with fast oxygen scavenging speed and good corrosion inhibitor performance, which can form a good passivation protective film on the surface of the metal. The content of this component in the agent is 5-15 parts by weight, preferably 8-13 parts.

[0063] In one example, the acetaldoxime is 10 parts.

[0064] In the preparation method of the embodiment of the present application, the acetaldoxime is 10 parts by weight.

[0065] In one example, the ethanolamine is 9 parts, the aminopropionic acid is 5 parts, and the hydrazine hydrate is 4 parts by weight.

[0066] In this example, by setting the addition amount of the above-mentioned three substances to the above-mentioned values, the scale stabilizer has good reducing performance, thereby preventing the generation of oxide scale and effectively removing dissolved oxygen in the boiler water, further avoiding the generation of oxide scale.

[0067] In one example, the N,N-diethylhydroxylamine is 15 parts.

[0068] In the preparation method of the embodiment of the present application, the N,N-diethylhydroxylamine is 15 parts by weight. In this example, the pollution stabilizer can form a stable protective film on the surface of the furnace wall, and the anti-corrosion effect is more excellent.

[0069] <Embodiment>

[0070] In this example, the various raw materials of the pollution stabilizer are as follows by weight: dodecahydrodiphenylamine 20 parts, triethylamine 25 parts, morpholine 20 parts, ethanolamine 8 parts, aminopropionic acid 4 parts, hydrazine hydrate 3 parts, acetaldoxime 10 parts, N,N-diethylhydroxylamine 15 parts, and desalted water 15 parts.

[0071] The preparation method of the pollution stabilizer is as follows: first, desalted water is added to a first reaction kettle, and then the dodecahydrodiphenylamine, the morpholine, the N,N-diethylhydroxylamine, and the triethylamine are sequentially added to the first reaction kettle to form a first mixed solution, the first mixed solution is stirred for 30 minutes, and the temperature of the first reaction kettle is 50°C; then, acetaldoxime, ethanolamine, hydrazine hydrate, and aminopropionic acid are added to a second reaction kettle to form a second mixed solution, the second reaction kettle is sealed, the second mixed solution is stirred for 40 minutes and then left to stand, and the temperature of the second reaction kettle is 30°C; finally, the first mixed solution and the second mixed solution are mixed in a third reaction kettle, stirred for 70 minutes, left to stand for 1 hour, and the temperature of the third reaction kettle is 40°C; wherein the material of the first reaction kettle is 304 stainless steel, the material of the second reaction kettle is glass steel, and the material of the third reaction kettle is glass steel.

[0072] After the pollution stabilizer is diluted 200 times with desalted water, the measured mass concentration of phosphate is 38 mg / L.

[0073] 1. Corrosion test

[0074] (1) The pollution stabilizer of the embodiment of the present application

[0075] The pollution stabilizer prepared by the embodiment is used. A high-pressure reaction kettle is prepared to simulate the working condition of a boiler. The high-pressure reaction kettle contains desalted water. The heating temperature of the desalted water in the high-pressure reaction kettle is 150°C, and the pressure in the high-pressure reaction kettle is 3 Bar. The pollution stabilizer is added to the high-pressure reaction kettle according to the dosage of 6 ppm. A cuboid hanging piece is placed in the high-pressure reaction kettle for soaking for 72 hours to test the corrosion rate. The material of the hanging piece is 20# boiler steel. The weight loss method is used to measure the corrosion rate of the hanging piece. The test data are shown in Table 1:

[0076] Table 1 - Weight loss method corrosion rate of the pollution stabilizer of the embodiment of the present application

[0077]

[0078] It can be seen that the corrosion rate of the pollution stabilizer of the embodiment of the present application on the 20# boiler steel is 0.00064g / m 2 ·h. After the coupon is corroded for 72 hours, the surface of the coupon is brown as a whole without pitting phenomenon. This indicates that a protective film has been formed on the surface of the coupon.

[0079] (1) Existing water treatment agent

[0080] The existing water treatment agent includes ammonia water and hydrazine. The dosing amount of ammonia water and hydrazine is 5ppm, and the weight ratio is 2:3. The test conditions of the corrosion test are consistent with the test conditions of the corrosion test of the pollution stabilizer of the embodiment of the present application. The corrosion rate of the coupon is measured by the weight loss method. The test data obtained are shown in Table 2:

[0081] Table 2 - Corrosion rate of existing water treatment agent by weight loss method

[0082]

[0083] It can be seen that the corrosion rate of the existing water treatment agent on the 20# boiler steel is 0.09232g / m 2 ·h. Pitting phenomenon occurs on the surface of the coupon. The corrosion rate of the pollution stabilizer of the embodiment of the present application is much smaller than that of the existing water treatment agent. The pollution stabilizer of the embodiment of the present application has a better slow-release effect.

[0084] 2. Use in boiler

[0085] The pollution stabilizer of the embodiment of the present application is applied in a boiler of a certain chemical plant. The steam production of the boiler is 220 tons / hour, and the steam pressure is 9.8MPa. The blowdown rate of the boiler before and after the addition of the pollution stabilizer is measured. The blowdown rate of the boiler refers to the ratio of the water quantity of the boiler water containing large amounts of salt and alkali, and the water quantity of the deposited water slag, sludge and loose sediment to the evaporation quantity of the boiler, which needs to be removed from the boiler in order to control the water quality of the boiler to meet the specified standard during the operation of the boiler. The dosing amount of the pollution stabilizer is 10ppm. The measurement results are shown in Table 3. The steam-water indexes of the boiler are shown in Table 4. Among them, the national standard is the feed water iron ion content, the steam silica content and the steam hydrogen conductivity specified in the Water and Steam Quality Standard for Thermal Power Generating Units and Steam Power Equipment (GB / T 12145-2016).

[0086] Blowdown rate = blowdown water quantity (Qblowdown) / boiler evaporation quantity (Qsteam) x 100%

[0087] The blowdown water quantity (Qblowdown) refers to the total amount of blowdown water of the boiler within a certain time. The boiler evaporation quantity (Qsteam) refers to the total amount of steam generated by the boiler within the same time.

[0088] Table 3 - Blowdown rate of the boiler before and after the addition of the pollution stabilizer

[0089]

[0090] Table 4 - Steam-water index of the boiler (measured after 28 days of operation)

[0091] Item National standard After adding the sewage stabilizer Iron ion content of feed water (μg / L) ≤30 ≤10 Silica content in steam (μg / L) ≤15 5.19 Hydrogen conductivity of steam (μs / cm) ≤0.15 0.1

[0092] In summary, after adding the blowdown stabilizer of the present application, the steam-water index of the boiler meets the national standard. The opening of the blowdown valve of the blowdown is significantly reduced, and the blowdown frequency is reduced from twice a day to once every seven days. The blowdown rate of the boiler is reduced from 3.0% to 3.5% to 0.5% to 0.85%. It can be seen that the blowdown stabilizer can significantly reduce the blowdown rate of the boiler. In addition, during the operation of the boiler, the surface of the furnace body is scale-free, corrosion-free, and the coating is complete.

[0093] The above examples focus on the differences between the various embodiments. The different optimization features of the various embodiments can be combined to form a more optimal embodiment as long as they are not contradictory. In consideration of the brevity of the writing, it will not be repeated here.

[0094] Although some specific embodiments of the present application have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration and are not intended to limit the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A blowdown stabilizing agent for a boiler feedwater system, characterized by, dodecahydrodiphenylamine, triethylamine, morpholine, ethanolamine, aminopropionic acid, hydrazine hydrate, acetaldoxime, N,N-diethylhydroxylamine and desalted water; wherein, the dodecahydrodiphenylamine is 15-25 parts by weight, the triethylamine is 10-30 parts by weight, the morpholine is 10-25 parts by weight, the ethanolamine is 5-10 parts by weight, the aminopropionic acid is 4-5 parts by weight, the hydrazine hydrate is 2-5 parts by weight, the acetaldoxime is 5-15 parts by weight, the N,N-diethylhydroxylamine is 10-20 parts by weight and the desalted water is 5-20 parts by weight; and The preparation method of the blowdown stabilizer is as follows: first, desalted water is added into a first reaction kettle, then the dodecahydrodiphenylamine, the morpholine, the N,N-diethylhydroxylamine and the triethylamine are sequentially added into the first reaction kettle to form a first mixed solution, the first mixed solution is stirred for 30 minutes, and the temperature of the first reaction kettle is 50℃; then, acetaldoxime, ethanolamine, hydrazine hydrate and aminopropionic acid are added into a second reaction kettle to form a second mixed solution, the second reaction kettle is sealed, the second mixed solution is stirred for 40 minutes and then is left to stand, and the temperature of the second reaction kettle is 30℃; finally, the first mixed solution and the second mixed solution are mixed in a third reaction kettle, stirred for 70 minutes, left to stand for 1 hour, and the temperature of the third reaction kettle is 40℃; wherein, the material of the first reaction kettle is 304 stainless steel, the material of the second reaction kettle is glass steel, and the material of the third reaction kettle is glass steel; The phenothalin alkalinity of the solution of the blowdown stabilizer diluted 100 times with desalted water is greater than or equal to 200 mg / L, density at 25°C is 0.9 g / cm 3 - 1.0 g / cm 3 ; The addition amount of the blowdown stabilizer in the boiler water is 3-20 ppm.

2. The blowdown stabilizing agent for a boiler feedwater system according to claim 1, characterized by, The dodecahydrodiphenylamine is 20 parts by weight.

3. The blowdown stabilizing agent for a boiler feedwater system according to claim 1, characterized by, The triethylamine is 12-18 parts by weight.

4. The blowdown stabilizing agent for a boiler feedwater system according to claim 1, characterized by, The ethanolamine is 6-8 parts by weight.

5. The blowdown stabilizing agent for a boiler feedwater system according to claim 1, characterized by, The morpholine is 14-16 parts by weight.

6. The blowdown stabilizing agent for a boiler feedwater system according to claim 1, characterized by, The hydrazine hydrate is 3-4 parts by weight.

7. The blowdown stabilizing agent for a boiler feedwater system according to claim 1, characterized by, The acetaldoxime is 8-13 parts by weight.

8. The blowdown stabilizing agent for a boiler feedwater system according to claim 7, characterized by, The acetaldoxime is 10 parts by weight.

9. The blowdown stabilizing agent for a boiler feedwater system of claim 1, wherein, The ethanolamine is 9 parts, the aminopropionic acid is 5 parts and the hydrazine hydrate is 4 parts by weight.

10. The blowdown stabilizing agent for a boiler feedwater system according to claim 9, characterized by, The N,N-diethylhydroxylamine is 15 parts by weight.

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