What is the difference between sludge and scale Why are they harmful to boiler operation?

What is the difference between sludge and scale Why are they harmful to boiler operation?

1 Due to heating, the salt containing water will get concentrated and changes into loose and slimy precipitates called sludge. 1 When these precipitates becomes hard and adherent called scales. 2 Sludge is not harmful for boiler. 2 Scales is harmful for boiler.

How are scales and sludge formed?

If the precipitation takes place in the form of loose/slimy precipitate, it is known as sludge. If the precipitation takes place in the form of a hard, adhering crust/coating on the inner walls of the boiler, it is known as scale. Sludge: It is a soft, loose and slimy precipitate formed within the boiler.

What are the disadvantages of scale and sludge formation?

1. Decrease in Efficiency of Boiler : The excessive scale formation may cause clogging of boiler tubes which decreases the efficiency of the boiler. 2. Wastage of Fuel : Scale is a poor conductor of heat.

What is scale in a boiler?

Boiler scale is a deposit that forms directly on heat transfer surfaces when constituent solubility limits are exceeded and the resulting compounds precipitate onto the tube surfaces. Such deposits may contain calcium, magnesium, phosphate, iron, and silica.

Why scales are more harmful than sludge?

Sludges are poor conductor of heat, so they tend to waste a portion of heat generated. If sludges are formed along with scales, then former gets entrapped in the latter and both get deposited as scales. Excessive sludge formation disturbs the working of the boiler.

What are scale and sludge give the names of salts responsible for them?

When their saturation points are reached, the dissolved salts of calcium and magnesium along with other soluble impurities are precipitated on the inner walls of boilers and in due course of time adhere to the metal surface in the form of scales and sludges.

What is an example of a scale?

Scale is defined as a system or series of marks used for measuring or registering. An example of scale is what someone would use to figure out the length of something. An example of scale is what someone would use to find out how much they weigh.

How scale is formed in boiler?

Scales are formed out of salts. These salts come inside the boiler through water in form of soluble solids and are precipitated when the concentration level increases because of evaporation. Scales are basically crystalline and more difficult to remove.

What is scale and sludge?

If the precipitation takes place in the form of loose and slimy precipitate, it is called sludge. On the other hand, if the precipitated matter forms a hard, adhering crust/coating on the inner walls of the boiler, it is called scale.

What is sludge in boiler?

Boiler sludge is a deposit that forms when suspended materials present in the boiler water settle on, or adhere to, hot boiler tubes or other surfaces. Sludge may be formed from a combination of whatever suspended materials are in the water, including loose corrosion products, insoluble mineral precipitates and oil.

How scale and sludge can be removed?

An internal treatment is accomplished by adding a proper chemical to boiler water either : (a) to precipitate the scale forming impurities in the form of sludges, which can be removed by blow-down operation, or (b) to convert them into compounds, which will stay in dissolved form in water and thus do not cause any harm …

What’s the difference between scale and sludge in a boiler?

When water converts into steam conc of dissolved salt inc, after reaching a saturation level the salts are thrown out in form of ppts. This is sludge.while scale is a hard and adherent deposit on the surface of boiler. Wiki User

What do you mean by scales and sludge?

By scales and sludge as far as i can understand that you are referring to “Boiler scales and sludge” which develops due to impurities and deposition of salts inside the boiler. Scales are harmful both economically and factory environment safety.

What’s the difference between sludge and a ladder?

Industrial wastewater treatment plants produce solids that are also referred to as sludge, whether generated from biological or physical-chemical processes. A ladder; a series of steps; a means of ascending. An ordered, usually numerical sequence used for measurement, means of assigning a magnitude.

What do you mean by sewage and sludge?

Sewage means waste water and excrement including the outlets of kitchen, bathroom and even industries. Sludge is a solid precipitated material obtained during the treatment of effluents before discharging them into water bodies by the waste water treatment plants.