Feedwater is water that undergoes purification or preheating and is then supplied to boilers for hot water and steam production, or it can remain still. It is typically found in thermal power plants where it is stored and conditioned in tanks, known as boiler feedwater.
What are the requirements of boiler feed water?
Boiler water treatment is used to control alkalinity, prevent scaling, correct pH, and to control conductivity. The boiler water needs to be alkaline and not acidic, so that it does not ruin the tubes. There can be too much conductivity in the feed water when there are too many dissolved solids.
How do you treat boiler water feed?
One of the most common and efficient combination treatments is the hot lime-zeolite process. This involves pretreatment of the water with lime to reduce hardness, alkalinity and in some cases silica, and subsequent treatment with a cation exchange softener.
What are the boiler feed water problems?
When treating boiler feed water (the combination of boiler makeup and condensate return water), several issues can arise that cause boiler scaling, corrosion, fouling, and system failure.
What is the difference between feed water and boiler water?
Cooling water is used in industrial processes to dissipate large amounts of heat. Boiler feed water, on the other hand, is used in the water/steam circuit for electricity generation in power stations. The water has to meet specific requirements for both applications, which is why it is analyzed on a regular basis.
Which water is used as boiler feed water?
The boiler receives the feed water, which consists of varying proportion of recovered condensed water (return water) and fresh water, which has been purified in varying degrees (make up water). The make-up water is usually natural water either in its raw state, or treated by some process before use.
How do you remove oxygen from boiler feed water?
Heat is the most common method for removing oxygen. Typical deaeration for smaller boilers utilizes a spray or combination spray and tray system to remove oxygen. The feed water is sprayed into a stream of 5 psig steam for efficient heat transfer and subsequent oxygen removal.
What should be the TDS of boiler feed water?
ABMA recommended feed water chemistry limits for steam boilers
| Boiler Operating Pressure (psig) (bar) | Total Dissolved Solids – TDS – (ppm) | Total Suspended Solids (ppm) |
|---|---|---|
| 0 – 50 0 – 3.5 | 2500 | |
| 50 – 300 3.5 – 20 | 3500 | 15 |
| 300 – 45020 – 30 | 3000 | 10 |
| 450 – 600 30 – 40 | 2500 | 8 |
What temperature is boiler feed water?
between 185 and 195°F The temperature of the feedwater tank should be maintained between 185 and 195°F (85 and 90°C) to reduce the amount of oxygen in the water. By increasing the temperature and reducing the oxygen content, you can greatly reduce your sulfite or oxygen scavenger requirements.
What chemicals you should apply on boiler feed water?
The most common alkaline solutions for boiler water include sodium hydroxide and potassium hydroxide. You can typically purchase these products with a 25 percent concentration or a 50 percent concentration.
Which of the following should not be a composition of boiler feed water?
2. Which of the following should not be a composition of boiler-feed water? Explanation: Its caustic alkalinity should be 0.15-0.45 ppm. … Explanation: Excess of impurities in boiler-feed results in scale and sludge formation, corrosion, priming, foaming and caustic embrittlement.
What issue do chlorides cause in boilers?
Chloride ion It causes generation of scale formation. The more the chloride ions, the more the scale formation. Therefore,it is necessary to limit it as low as possible. The problem with chloride ions is that high degree of dissolution makes it difficult to remove them at a later stage.
What will happen if oxygen dissolves more in boiler water?
Dissolved oxygen will react with carbon steel throughout the feedwater piping, economizers, and boiler, causing oxygen pitting and eventually leaks. … This acid condensate will corrode your steam piping while also adding iron to your boiler water.
What is boiler feed water What are common problems of boilers explain any one?
2. Common issues found on Boiler feed water due to scaling. … Hardness in the feed water will usually present problems in relation to the operation of boilers. Hardness of more than 5dH° (90 ppm as CaCO3) in the feed water will, as the temperature rises, cause an increase in the formation of sludge in the feed water tank …
How do I build a boiler feed?
What is priming and foaming?
Bubbles or froth actually build up on the surface of the boiler water and pass out with the steam. This is called foaming and it is caused by high concentration of any solids in the boiler water. … Priming may be caused by improper construction of boiler, excessive ratings, or sudden fluctuations in steam demand.
Is boiler feed water should also be hard in nature?
Dissolved solids Hence, it is quite essential that they are restricted from going inside the boiler. Dissolved solids include impurities like Hardness, sulfates carbonates etc. Natural water also has silica dissolved in it which can form hard scales.
What is pH in boiler water?
Boiler pH. Natural water is usually between 6.5 and 7.5 pH. A common recommendation is to maintain boiler water at 8.5 pH.
Why demineralized water is used in boiler?
Boiler is used to produce steam for power generation. The feed water to the boiler has to be treated to protect against scaling and produce high quality steam. Scale is precipitated impurities out of the water and then forms on heat transfer surfaces. … This type of water is known as demineralized water.
What is open feed system?
In an open feed system, steam from various systems comes to the condenser and gets converted into water. This condenser is continuously circulated with sea water and operates under certain atmospheric pressure or slight vacuum. The condensate, under the effect of gravity goes to the hot well and feed filter tank.
What is the purpose of deaeration?
Deaerators are mechanical devices that remove dissolved gases from boiler feedwater. Deaeration protects the steam system from the effects of corrosive gases. It accomplishes this by reducing the concentration of dissolved oxygen and carbon dioxide to a level where corrosion is minimized.
What causes high CO in a boiler?
If the oxygen level is set too low and something changes the combustion process can become ‘fuel rich’ as there is insufficient oxygen for all the fuel to burn. This can cause high levels of CO to be generated and in the extreme enough fuel to enter the boilers flue and ignite (explode) outside the combustion chamber.
Does steam has more oxygen?
Steam is denser than Oxygen or Natural Gas, but lighter than Sour Gas and Chlorine.
What is the TDS of RO water?
Acceptable. However, the TDS level in the range of 80-150 is considered ideal. If you are using an RO water purifier then make sure the TDS level of purified water is not below 80 mg/L. …
| TDS Level (mg/l) | Rating |
|---|---|
| Less than 300 | Excellent |
| 300-600 | Good |
| 600-900 | Fair |
| 900-1200 | Poor |
What happens if TDS is low in boiler?
The boiler TDS level would increase, and priming and carryover would occur. Reduce – The orifice would pass too much water. The blowdown rate would be too great and energy would be wasted.
What is conductivity in boiler feed water?
A common problem that’s found in boiler water is the presence of high conductivity, which refers to the ability of the water to conduct an electrical current. Controlling the conductivity of water is an essential component of making sure that a boiler functions properly.
How do you calculate boiler feed water?
The feedwater flow rate can be calculated from steam mass flow and blowdown rate:
- Blowdown Mass Flow = Feedwater Mass Flow * Blowdown Rate.
- Steam Mass Flow = Feedwater Mass Flow – Blowdown Mass Flow.
- Steam Mass Flow = Feedwater Mass Flow – Feedwater Mass Flow * Blowdown Rate.
How do I size a boiler feed tank?
Another quick rule of thumb is that 1/10 of a gallon is needed for every boiler horsepower. So a 500 HP boiler will need a pump capable of delivering 50 gpm. An 800 HP boiler will need an 80 gpm pump.
What is a boiler hotwell?
noun. a tank or reservoir in which hot water is collected before being recirculated, especially condensed steam about to be returned to a boiler.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.