Hot water treatment
AMELIN products for boiler feed water treatment are used in a wide range of applications to control corrosion and to maximize heat exchange through deposition control and prevention of scaling. Treatment programs by AMELIN maximize energy efficiency thus reducing the operational costs. Besides, AMELIN treatment programs reduce capital costs by extending the service life of the system components.
Boiler feed water treatment products by AMELIN have following codes according to the application:
| Application | Product |
|---|---|
| Pretreatment regenerates | AM 2000 |
| Oxygen absorbers | AM 2100 |
| Internal treatment | |
| One tank mix | AM 2200 |
| Polymer products | AM 2300 |
| Phosphate products | AM 2400 |
| Chelant products | AM 2500 |
| Dispersants and other products | AM 2600 |
| Steam and condensate treatment | AM 2700 |
Composition and effect
AM 2100 - 2600 products possess the properties and are composed of mainly caustics, sulphites, antifoam agents, and polyacrylate. Deposition and sedimentation control is achieved through crystalline modification and destruction. These mechanisms are activated by a number of stable phosphonates, phosphates, and synthetic copolymers.
| Component | |
|---|---|
| Sodium hydroxide or sodium carbonate | Maintains the alkali balance required for the fallout of the desirable phosphate precipitate. In combination with the silicon naturally occurring in the boiler feed water, alkalinity precipitates magnesium hardness salts as wavy residue |
| Sulphite or organic absorbers | Absorb dissolved oxygen by reacting with it, thus minimizing oxygen-type corrosion |
| Dispersants (Polymers) | React with precipitated hardness salts generating highly hydrated, light, and nonviscous coat that can be easily removed during scheduled discharge of the boiler bottom sediment |
| Antifoam agents | Prevent blowout of water due to foaming by increasing the surface tension of the boiler feed water and creating conditions favorable to the generation of large and unstable (easily bursting) steam bubbles |
| Phosphonate | Threshold stabilizer for metallic cations such as calcium, magnesium, iron. (Threshold effect is the ability of substoichiometric (small) amounts of a material to control the precipitation of large amounts of another material that precipitates in normal conditions |
| Phosphate | Prevents the build-up of calcium salts coat on steam generating surfaces of the boiler by forming calcium hydroxyapatite precipitate on them |
| Chelant | Prevents the build-up of calcium and magnesium salts coat on the boiler pipes by binding them into soluble metal complexes |
Pretreatment regenerators
AMELIN regenerates are able to remove all contaminated anionic or cationic ion exchange resins and can be used as a part of the general maintenance program. AM 2001 is an effective detergent used to remove ferrous contaminants from cationic resins and hardness salts that can block the openings in the softener regulator's cover. When fed routinely into the brine tank, AM 2001 maintains ferrous contaminations on the predefined level and extends the period between ionite bed and brine tank cleanings.
AM 2002 removes organic contamination from the both resin types. Due to its nonionic origin, AM 2002 is compatible with both cationic and anionic resins. Where the resin has been contaminated by organic and inorganic substances, successive decontamination with AM 2001 and 2002 products is required.
AM 2003 and AM 2004 are organic acids and amines mixtures with a low partition coefficient used to convert the cationic resin in the condensate purification filter from sodium to amine form. The advantage of this conversion is that unlike sodium filters, amine filter do not affect the pH of the agreed phosphate/pH program. Since the boiler water is kept in a nonaggressive state, boiler reliability improves.
| Product | Application |
|---|---|
| AM 2001 | Removes inorganic contaminants |
| AM 2002 | Removes organic contaminants from cationic and anionic resins |
| AM 2003 | Designed specifically for agreed phosphate programs of reduction of sodium separation from sodium form filters. Maintains certain pH buffer for the boiler water |
| AM 2004 | Designed specifically for agreed phosphate programs of reduction of sodium separation from filters. Maintains certain pH buffer for the boiler water |
Oxygen absorbers
Inorganic oxygen absorbers AM 2100
Inorganic oxygen absorbers by AMELIN are sulphides in a powder or liquid form. Most of them are catalyzed with cobalt.
2100 series benefits:
AM 2100 series products effectively absorb dissolved oxygen, especially in the feed water temperature range. These products are very cost-effective, easy to feed and to monitor the treatment level, and are ideal for boiler systems with softened water. Besides, products are available with a high catalyzation grade, nonacid liquids, powders, and/or low odor products. In systems operating at pressures higher than 6.0 MPa and in systems using the boiler feed water for cooling after overheating, temperature regulation or agreed phosphate programs, sulphite-based products must be substituted for AMELIN organic oxygen absorbers.
AMELIN organic oxygen absorbers AM 212х
Advantages
AM 212х products can be adjusted to almost any application. They are ideally suited to systems with high water purity and systems with boiler feed water temperature control and cooling after overheating.
AMELIN organic oxygen absorbers offer the widest possible choice of the industrial oxygen absorber molecular composition.
- Hydroxylamine and hydrazine compounds. Following molecules are available: Diethyl hydroxylamine (DEHA) and carbohydrazide (CHA). CHA main effect is absorption with high heat stability and volatility, while DEHA has better distribution properties that offer certain benefits for condensate treatment purposes.
- Ascorbic acid (AA) is approved for applications with the use of open steam. This product is partially neutralized and has best reactive properties at neutral pH.
- Hydroquinone (HQ) is a very effective organic oxygen absorber, even at room temperature.
Organic oxygen absorbers
AM 2200 - AM 2400 series products are suitable for the complete range of operational conditions that may exist in the operation of steam plants. This product line has been developed for any pressure within the range from 0 to 200 atm. In boilers operating at pressures higher than 70 atm, internal boiler treatment is a complicated procedure that requires appropriate preparation. On-site assessment is required for these systems. Special recommendations are issued for high pressure systems upon installation.
In systems operating at pressures from 0 to 70 atm, AM 2200 - AM 2400 series products have to be used after mandatory boiler feed water pretreatment that includes the use of sodium- zeolite softeners, reverse osmosis, nanofiltration, and demineralization. Besides, our products are suited to a broad range of conditions in terms of boiler feed water hardness and ferrous deposits.
AM 2500 contains chelant-based products. But they are custom limited use products.
| Product series | Description |
|---|---|
| AM 2200 | Combined oxygen control, internal boiler treatment, and condensate treatment in certain situations. Intended for small boiler systems where convenience is the main criterion. |
| AM 2300 | Deposition control program using polymers or polymer-phosphonate mix, intended mainly for softened water systems with pressure under 65 atm. Can be used as dispersants in phosphate-based precipitation programs |
| AM 2400 | Traditional PO4-based products, intended mainly for softened water systems with pressure under 65 atm. Special products have been developed and are available for boilers operated at over 70 atm. |
AMELIN internal boiler treatment products
| Boiler operating pressure | 200 atm
140 atm | Volatiles | Boilers operated at this high pressure without pretreatment are a source of HAZARD.Preliminary investment required. | |
| Equilibrium PO4 program (2500) | ||||
| 70 atm | PO4/pH balance (2400)
Phosphate mixes (2400) Polymers (2300) | Phosphate mixes (2400)
Polymers (2300) | ОBoiler service life estimate is low. Preliminary investment recommended | |
| 50 atm | Phosphate mixes (2400)
Phosphonate-polymer mixes (2300) | Phosphate mixes (2400)
Phosphonate-polymer mixes (2300) | Phosphate mixes
(2400)
Phosphonate-polymer mixes (2300) | |
| Feed water contaminants | Fe < 0.1 mg/l
Hardness < 0.1 mg/l | Fe
and/or
Hardness < 0.1 mg/l | Hardness > 1.0 mg/l | |
| Pretreatment | Condensate or
demineralizers | NaZ, RO or Nano | ||
| Fe in feed water (mg/l) | 0
0,1 | 0,1
1,0 | ||
| Feed water hardness (mg/l) | 0
0,1 | 0,1
1,0 | 1,0
5,0 | |
Internal treatment
AM 2200
AMELIN AM 2200 series products combine agents that control oxygen corrosion (molybdate or sulphite), agents that control general boiler corrosion, and in certain instances condensate treatment agents in a single easy-to-feed mix. These products are suited mainly to small boiler systems (typically, boilers with operating pressure < 100 psi and low feed water demand), for which the key factors are simplicity, low labor input, and convenience.
Molybdate offers better oxygen corrosion control than sulphite in low pressure boilers. Molybdate-based 220x series products are used to maintain the molybdate deposition level.
Molybdate acts as a corrosion inhibitor forming a protective film on metallic surfaces. These products are fed irrespective of the stoichiometric ratio to oxygen.
Since molybdate treatment introduces neither sulphites nor sulphates, there is no calcium sulphate deposition. Molybdate treatment makes it possible to reduce the frequency of boiler bottom sediment collection.
Molybdenum treatment is a cost-effective alternative to the traditional sulphite treatment if the following applies:
- minimum boiler bottom sediment collection (>50 cycles);
- steam pressure is low (< 100 psi, typically 0-30);
- feed water demand is low (typically 10% or lower);
- calcium sulphate deposition problems have occurred.
Feed rate is calculated to maintain the standard level of sulphite, molybdate, or phosphate deposits in the boiler. Following factors should be taken into consideration during the calculation:
- Concentration cycles;
- Ultimate sulphite/molybdate/phosphate level.
AM 2300
AMELIN AM 2300 series products are polymer mixes used in systems contaminated mostly by hardness. Some products contain molybdenum tracers for simpler monitoring and control.
AM 2400 series polymer mixes effectively collect and remove hardness and ferrous contaminants improving boiler reliability and reducing the requirements to chemical cleaning of boiler during shutdown. These products are intended for systems with softened feed water where hardness is the main contaminant.
AM 2300 series products are universal internal treatment products that offer following benefits:
- No risk of polymer contamination
- Easily controllable
- Cost-effective
- Noncorrosive to boiler water and boiler metallic structures
- Tolerate excessive and insufficient feed
Special programs and modifications are required for steam systems fed with demineralized or reverse osmosis water or operated at pressures over 900 psi.
Phosphate products
AM 2400 series products are phosphates and phosphate-polymer mixes. One of the products contains sodium sulphite, and three products contain some phosphonates.
These products are intended for boilers with softened feed water where hardness is the main contaminant.
Advantages:
AM 2400 series products effectively collect and remove hardness and ferrous contaminants improving boiler reliability and reducing the requirements to chemical cleaning of boiler during shutdown. Products are easily controllable, offer cost-effective treatment regime, are noncorrosive to the feed water and boiler's metallic structures, tolerate temporary insufficient or excessive feed of the product. Special recommendations by AMELIN must be followed concerning applications with demineralized or reverse osmosis feed water.
Chelant products
AM 2500 series products are chelant/polymer mixes for small, medium, and large budgets. The series is based on the concept of conditioning the boiler feed water's hardness components by combining them with chelants. OH alkalinity control is critical for chelant-based products, similarly to phosphates. Minimum OH value of 150 p/min must be maintained in the boiler to minimize corrosion and to form the required complex of Ca, Mg, and soluble Fe ions.
Another advantage of Chelsea/polymer products is based on the earlier research indicating that more magnetite is formed when EDTA is used.
Application scope of these products is limited to flue boilers operating at under 150 psi, specifically excluding tubular boilers. Recommendations regarding the use of chelant compounds are given in special manuals.
Dispersants and other products
AM 2600 series products are polymer conditioners of deposits and dispersants that have been developed to create the required conditions and to remove solid particles from the boiler feed water and for different budgets. The series combines effectiveness of both specific single polymers and polymer mixes thus meeting the demand for any dispersant for the boiler feed water solid particles.
These products make our boiler feed water treatment programs especially flexible and can complement any phosphate or chelant-based program. The majority of the 2600 series products contain effective defoaming agents for boiler feed water.
Return line treatment - amine mixes
Return of the condensed steam in the condensed form is a critical phase in terms of efficiency for any steam generation systems. Its economically feasible to return as much condensate as possible. Though the recycled condensate may lead to the corrosion of the pipes it flows through. At certain moments boiler feed water tests may indicate that the internal treatment status is satisfactory but actual inspection of the boiler's interior may reveal deposition of metal oxides that could have penetrated the area only with the condensate.
Hence, correct treatment of the condensate is of paramount importance for the proper functioning of the steam generation system. Actually, all corrosion in the steam and return lines is related to carbon dioxide. In the presence of CO2 and O2 the reaction goes much faster than in the presence of only one of them.
Oxygen corrosion (more rare) is characterized by deep cavities throughout the pipe walls surface. CO2 corrosion results in grooves throughout the pipe length and in thinning of connection areas. The solution by which the corrosion, especially the CO2 corrosion, in the steam and return lines can be mitigated is to use amine-based products, of both the neutralization and film-forming types. Neutralizing amines, that are compounds with volatile oxygen absorbers, prevent oxygen corrosion in systems plagued by this problem.
AM 2700 series return line treatment products are the most effective of the available mixes. They are combined products based on neutralization and/or film forming and/or volatile oxygen absorbers.
No boiler feed water treatment program can be considered complete without return line treatment. The only exclusion are the food and petrochemical operations where the presence of amine would destroy certain catalysts and food products. In this case external treatment solutions are used to mitigate CO2 impact.
Post-flame zone
| Problem | Symptoms | Consequences | Solution |
|---|---|---|---|
| Slagging and corrosion | Steam temperature falls
High temperature at the pipe outlet Overheated steam Excessive downtime Boiler burns out | Weaker heat
transfer
Higher resistance in the gas path Lower boiler efficiency Equipment damage | Improve fuel quality
Improve boiler design Increase the melting temperature of the soot components Make slags more loose Passivate the boiler surfaces |
Pre-flame zone - fuel additives
| Product | Application |
|---|---|
| AM 2805 | Fuel tank recirculation line |
| AM 2806 | Fuel tank recirculation line |
| AM 3406 | Fuel tank recirculation line |
Pre-flame zone - troubleshooting
| Problem | Symptoms | Consequences | Solution |
|---|---|---|---|
| Slag | Lesser tank capacity
Blocking/burnouts in the pre-flame zone and furnace Insufficient fuel alarm triggered | Tank cleaning costs
Higher fuel costs Low load Poor combustion | Tank recirculation
AM 2805 AM 2806 |
| Water | Tank corrosion
Flameout Growth of microflora | Tank repair and
replacement costs
Poor combustion | Tank recirculation
Decant water AM 2805 AM 3406 Biocide |
Combustion system treatment - Fuel additives
| Product code | Zone |
|---|---|
| AM 2801 | Combustion, incinerators |
| AM 2802 | Combustion |
| AM 2803 | Combustion |
| AM 2804 | Combustion, incinerators |
| AM 2805 | Pre-flame additives |
| AM 2806 | ПPre-flame |
AMELIN product line for effluent water comprised 8 series. Products from the 8 series are applied individually or in combination to achieve the following outcomes:
- Cleaning. Coagulants (5000 - 5100 series), flocculants (5200 series)
- Oil removal. Coagulants (5000 series), flocculants (5200 series), and/or deemulsifiers (5500 series)
- Removal of metals. Metal precipitants (5300 series), flocculants (5200 series), and possibly coagulants (5000 series)
- Dewatering. Flocculants (5200 series and occasionally coagulants (5000 series)
- Foaming control. Antifoam agents (5400 series)
Coagulation and flocculation - terms and definitions
Coagulation and flocculation are mechanisms that are used to increase by a chemical reaction the size of particles and then to remove them.
Coagulation means neutralization of the charge with positively charged (cationic) materials.
Flocculation is a physical mechanism of joining based mainly on the molecule size, rather than charge.
Cationic polymers and inorganic coagulants increase the size of particles by neutralizing negative surface charges of the particles by compressing the electrical layer and by electrostatic attraction.
Self-precipitating polymers and inorganic coagulants produce large particles by building interparticle bonds and by forming entrained floccules.
Anionic and cationic materials with a high molecular weight act mainly as flocculants building interparticle bonds.
Organic polymers act as coagulants and/or flocculants.
Polymers are synthetic polyelectrolytes that act as coagulants and/or flocculants. They bear a cationic, nonionic, or anionic charge. Polymers exist as powders, liquids, or emulsions. High molecular weight polymers exist as powders or emulsions.
Charge type, charge-to-mass ratio (charge density), and molecular weight determine which specific polymer should be used for which application.
Inorganic coagulants
Aluminum and iron salts are the most commonly used coagulants. They include aluminum sulphate, sodium aluminate, polybasic aluminum sulphates and chlorides, ferric sulphate, ferrous sulphate, ferric chloride, polybasic ferric salts. In addition to sodium aluminate, the said compounds are acid salts with pH value lower than than of water.
Starches and tannins
5100 series starches and tannins are liquid coagulants designed specifically for hard-to-treat effluents. This product series is based on the chemical properties of lignin, tannin, and starch. The effect is based on self-precipitation and/or neutralization of charge. The unique properties of these compounds are related to their organic origin - resulting floccules are not as large as those produced by inorganic coagulants, mainly because they absorb water to a lesser extent than inorganic precipitates.
Application:
These lignin, tannin, starch products surpass regular polymers in the treatment of effluents containing emulsified oils, colloidal materials, water-soluble oils, process oils, or hydrocarbon oils.
They offer a number of benefits including:
- Exclusive oil/water separation
- Small precipitate volume
- Reduced precipitate treatment costs
- Higher tolerance to changes in pH
- Ability to remove certain heavy metals
Typically, these materials possess small molecular weight and high cationic charge, which enables their use in a variety of effluent waters.
5200 series anionic flocculants:
To meet as stringent flow standards as possible AMELIN offers a series of metal removers. These products are based on organic sulphides containing negatively charged functional groups that form stable bonds with positively charged ions of metals in the solution to form insoluble precipitates.
| Series code: | 520x anionic emulsions | 521x anionic dry polymers | 521x anionic liquid polymers |
|---|---|---|---|
| Advantages | High concentration of solid particles in the form of a
liquid emulsion
Forms dense heavy floccules reducing the outflow of solids Used in many industries Typically, low consumption if combined with a flocculant Ideal for automatic batching | Cost effective
Form agglomerates quickly, thus reducing outflow Used for many types of industrial effluents and flowing water treatment systems Low consumption if combined with a flocculant | Products are liquid solutions, therefore no spray and
preparation systems are needed
Ideal for automatic loading and pure loading Can be loaded pure with a high viscosity pump |
| Series code: | 524x series | 525x series |
|---|---|---|
| Description: | Cationic emulsion polymers with high molecular weight | Cationic powder (dry) polymers with high molecular weight |
| Advantages: | Cost effective concentrated liquid emulsions
Form large easy-to-detach particles during cleaning and flotation Speed up the process of sludge dewatering and decrease sludge volume Improve the quality of the effluent oil flow Ideal for automatic loading | Cost effective
Form large easy-to-detach particles reducing the outflow of solid particles Reduce the sludge volume through better treatment |
Application notes:
These products are often used in further cleaning after the completion of standard removal procedures, e.g. hydroxide precipitation. But metal remover products can be used right in the hydroxide phase if the initial concentration of metals is under 100 mg/l.
Properties of metal removers:
- Direct precipitation of complex/chelated metals
- Broad applications range (different metals: Cu, Ni, Zn, Ag, Pb, Cd, Hg)
5400 series antifoam agents
Foam can cause numerous problems in cooling systems and process or effluent water treatment systems including filling with foam of vessels and pipelines, pump cavitation, odor and aesthetic problems, safety violations.
AMELIN offers several products to control and prevent foaming.
Key properties of these products are as follows:
- Oil, water, and silicone-based
- Simple feeding
- Suitable for different feeding systems
- Shipped with test, feed, and control devices to ensure correct product choice and feed
- Shipped as liquids and liquid concentrates
Key benefits offered by these products: