Using Ball Mills in the Energy Industry

By Andrey Sysoev  

Experimental studies on coals of different metamorphic grades and various fractional states were conducted in 2000 by the Institute of Thermal Physics of the Russian Academy of Sciences, at experimental thermal energy facilities. These showed that fine-ground coal, milled to a particle size of 15-30 microns, develops a highly reactive property that is analogous to fuel oil - to which it can become an alternative. The experimental facility was rated at up to 1000 kW, and equipped for use with ultra-fine ground coal (produced with an ultra-fine ball mill); burning (pre-furnace and furnace equipment); a plasma system and gas starter for ignition and supplementary firing; combustion control (an automated post for combustion control) and cleaning (a vortex scrubber). The results produced in these experiments can be used to establish the parameters needed in technological facilities for ignition systems and supplementary burning using coal-dust boilers - a replacement fuel for gas and fuel-oil boilers.

The conclusions from these theoretical and experimental studies pointed to the technical and economic viability of using ultra-fine ground coal as a new oil-free technology for the ignition and stabilisation of combustion in coil-fired boilers at power plants, in addition to the ability to replace liquid fuels in boilers.

The primary technological facilities for making use of this new technology are: equipment for ultra-fine milling (ball mills), and the supplementary equipment for supplying and combustion of coal. Technical designs for the supplementary equipment have been developed, which are essential for wheeling-out the new technology (muffle furnace apparatus, input nozzles for the coal dust, accelerating devices for igniting the primary fuel mixtures, feeders for fuel discharge, hoppers for storage, and so forth). Factories able to manufacture the new supplementary equipment already exist in Russia. The last-mentioned also produces milling equipment, and specifically ball mills for ultra-fine milling processes.

This new technology is low-cost, with a short return-on-investment cycle which will hit break-even in no more than 2 to 3 years. The additional financing costs are in producing the ultra-fine ground coal (the purchase of ball mill machinery) - the additional machinery also has a short investment payback cycle due to the economics of the fuel supply industry.

The new Plasma-fuel technology has now passed the final stages of certification - for pilot industrial use. This allows assessment of the risks of the new technology - and if required, it can be further honed to optimise its operation prior to finalising the business case which can be put to potential investors.

Converting oil-fired boilers to run on ultra-fine ground coal

The primary task is moving to rejecting the use of fuel oil by the facility in future. Of course, in places where it is available, it makes sense to change to using natural gas. However, where this is not an available option, then such facilities can be converted to run on ultra-fine ground coal. The economic result of making the change from fuel oil to ultra-fine ground coal will be in the greatly reduced cost of fuel. Over and above this, there is an environmental gain to be made - since there will be a marked reduction in the emission of sulphurous oxides into the atmosphere. This has a further economic benefit, in terms of decreased payments to be made for such emissions.

When making the changeover to using ultra-fine coal, the issue of disposal of the ash waste which it produces needs to be addressed. For facilities currently using fuel oil, this can be problematic. In the first instance, this issue could be resolved by making agreements to remove the ash and slag waste from the boiler room to nearby ash dumps or industrial sites. This process could lead to a loss of some of the cost benefits of making the changeover. But in a more positive light, the ash and slag waste can be recycled as a component in the manufacture of construction industry materials, mineral components, and similar by-products. Installing a production line for the recycling of slag and ash is not only a responsible way of negating environmental pollution - but can similarly cull in economic benefits.

This means that the issue of converting oil-fired power stations to run on ultra-fine ground coal can be easily resolved both technically and administratively. Each individual case for conversion should properly be put through a business plan, including a technical survey of the boiler equipment, and the prevailing economic situation.

Evaluating the efficiency

Energy efficiency can be determined by making a comparison with the costs of fuel oil operation (i.e. the current costs), against the projected costs of transferring the facility's operation to ultra-fine coal (the current costs, plus the cost of additional equipment). To make these estimates for the current costs, it follows that the costs of the current in-purchasing of fuel oil should be compared against the costs of purchasing coal, plus the additional electricity costs incurred in the grinding process. Particularly concerned with this latter cost, it pays to consider the choice of grinding machinery in the light of its electrical consumption costs. It makes obvious sense to purchase machinery with the lowest energy operating costs. Furthermore, when weighing up the decision to switch from fuel oil to ultra-fine coal, the operation of installing the additional equipment needed for ignition of the ultra-fine coal must be carefully considered.

Essential equipment:

The ball mill for grinding ultra-fine coal is essential. This kind of coal-grinding apparatus to create combustible fuel is traditionally divided into several categories. Quiet-Operation Slow Ball Mills operate with a rotation speed of 16-23 revs per minute. Fast-Action Tangential Mallet Mills have an operational speed of 590 to 980 revs per minute; and there are also Medium Roller Mills which rotate at 40 to 78 revs per minute. The table of ultra-fine coal dust obtained is below, depending upon the type of machinery chosen.

• Ball drum mills are used for grinding anthracite and bituminous coal with a milling operational range of ≤ 1.1 and low volatility required fine grinding (6... 7 %). If the raw source material to be milled includes some presence of pyrite sulfur fuel ( up to SP > 6 % ) then only ball mills can be used.
• Hammer mills are used for brown and black coal of relatively high volatility (Vg > 30 % ).
• Medium Roller Mills are used for grinding coals with a milling operational range of at least 1.1 Wp and humidity of no more than 16 %, with an ash content of no more than Ar 30 %

Additional Equipment required for producing the ultra-fine coal fuel:

• crusher
• crushed coal bunker
• coal feeder
• high-pressure fan
• coil-dust burner
• muffle furnace extension
• blowing fan
• milling shelf
• cyclone dust collector

The primary rationale for undertaking the technical changeover is to replace expensive and increasingly-scarce fuel oil - traditionally used for the ignition and stabilisation of combustion in coal-fired thermal plant boilers - and also to replace liquid fuel oil in boilers. Issues of economic efficiency in tandem with environmental responsibility should underlie decisions for making the changeover. Coal combustion can make up part or the whole of the combustion process in combination with other resources, and offers enhanced productivity for boiler equipment along with reductions in fuel consumption when producing energy through combustion processes, along with an improved level of cleanliness and purification in the resulting flue gases.

The Strommashina plant in Samara produces and installs all of the above-mentioned and recommended kinds of ballmill and mill machinery - as well as dryers, crushers, feeders, cyclones and separators. Strommashina has been producing reliable power generating machinery since 1942. Over that time, the corporation has been continuously honing its technology and quality control - thus resulting in Strommashina's appearance on the world market for industrial equipment. The company's specialist staff are on hand to offer their advice in designing and purchasing equipment, as well as providing expert technical advice and support at every stage of the design, set-up, inception and operation of the equipment they produce.

Strommashina's Strong Points

• Geographical convenience - Samara is a big transportation hub located in the middle of Eurasia. The railway sidings are part of Strommashina's Plant infrastructure. River port accessibility provides ease of connectivity to Europe and Central Asia.
• Installation supervision (comprehensive control over how equipment and production lines are installed and commissioned)
• 1 + year warranty

Have a question or need a quote? Please, feel free to Contact us!

Strommashina Corp.
22 Partsyezda st., 10a, Samara, Samara Oblast, Russia, 443022

Tel: +7 (846) 374-1741

Article Source: http://EzineArticles.com/expert/Andrey_Sysoev/2330153

Coal Power Plant

By Id Weha 

Coal power plant is a power plant that uses coal as fuel. The working principle of coal power plant is a coal-yard of Coal will be transferred by using a belt conveyor to the coal bunker. Coal from the coal bunkers will be destroyed in the Pulverizer so it becomes very soft powder. From Pulverizer then circulate to the burner on the boiler, in this area will be combustion burner and will heat the tubes in the boiler. Due to this heating water in a tube going up above the boiling point to produce steam, then steam is used to drive turbines that function to produce mechanical energy to drive the generator. In this generator of electrical energy generated by the principle of changes in the lines of magnetic force.

For the water-steam cycle usually use a closed cycle in which water used to produce steam main is the same water that the Circulate and continue to be used for the next cycle, it is only necessary to add water (makeup water) when the volume of water is less than set point her.

Water used is treated seawater using MED (Multi Effect Desalination) into fresh water. Furthermore, the water is purified through a process of filtration and ion exchange system through Water Treatment Plant equipment. Pure water that has been processed through the Water Treatment Plant is channeled into the water charging system boilers. The process begins with the initial combustion in the boiler where to start burning fuel oil used as fuel, but when the load has reached 30% then the furnace is hot enough and began to include coal as fuel until the load reaches 100%. After the temperature in the boiler has sufficient fuel oil to be replaced with coal.

Water will be pumped using a Boiler Feed Pump (BFP) through Economizer then subsequently taken to the Steam Drum. In the steam drum is separated between the steam and water. Fluid which still has a liquid phase is circulated through Wall Tube to be heated which is then channeled back to the Steam Drum. Vapor phase in Steam Drum channeled toward primary superheater and then proceed to the Platen superheater and Secondary superheater. After going through the superheater, the superheat steam flow to the High Pressure Turbine (HP Turbine) to be expanded. After experiencing an expansion in the turbine the steam pressure and temperature will decrease the output of the turbine so it needs to reheat. Performed in Reheater reheating.

From Reheater, steam will be entering the Intermediate Pressure Turbine (Turbine IP) and then proceed to the Low Pressure Turbine (Turbine LP). At Turbine energy change of thermal energy that brought steam into mechanical energy. Mechanical energy in the form of round rotor is used to drive turbine generators. In the generator mechanical energy is converted into electrical energy.

Steam coming out of the LP turbine and then condensed in the condenser with seawater as cooling water medium. Therefore, the vapor condenses on the output conditioning condenser in order fluid material unless the state of saturated liquid minimal. Charging system of water into the boiler from the condenser is pumped by Condensate Pump streamed to Deaerator, where water that has been entered will first be passed Condensate Polishing Plant and heating low pressure Low Pressure Heater channeled toward Deaerator.

In Deaerator separated O2 and other non-condensable Gases. Water that has undergone a process deaerasi is accommodated in a Storage Tank to be channeled into the boilers at the next cycle by using the Boiler Feed Pump.

Water is pumped to the boiler filler Boiler Feed Pump for the first flow is passed High Pressure Heater and economizer to heat the water entering the boiler at or commonly known as preheater before entering the steam drum. Deaerator and high pressure heating gets heat from steam turbines or retrieval (Extraction Steam Turbine). As for the economizer is getting heat from boiler flue gas remaining after heating the superheater. After water vapor from the economizer and water will be accommodated in the steam drum.

This cycle will always be repeated endlessly (closed cycle), although repetitive but still need the addition of more water from the Water Treatment Plant to the condenser for the looping of water due to evaporation of water leaks and steam heat in the heating process or also the reduction of water by blowdown system.

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Article Source: http://EzineArticles.com/expert/Id_Weha/1214819

A Guide on Industrial Fans

By Lilian Gray  

Industrial fans provide high static pressure. These fans can blow out stagnant air in wide areas and recirculate that air. Because of that, they are often used in areas where the following issues occur often:

• stagnant air
• heat stratification
• dampness

How do Industrial Fans Work?

Most industrial fans utilize the same technology that one would find in any portable fan. A blade forces air to move alongside a shaft. The blades rotate around that shaft. This produces a wind chill effect. Industrial fans, however, are usually larger and more durable. They are often equipped with stronger motors so that they are not as loud.

Why Buy an Industrial Fan?

Industrial workplaces include:

• warehouses
• factories
• plants
• distribution centers etc.

Such large places can become absolutely miserable as they hit extreme temperature levels. This, of course, creates a much larger power bill but is also very uncomfortable for workers. It is a not a happy, healthy and safe work environment when it is too hot or the air is stagnant. This has to do with thermal comfort, which greatly affects people's motivation and ability to work.

What is Thermal Comfort?

Thermal comfort is whether someone feels too hot or too cold. A lot of factors can affect this. It can have to do with personal issues, personal health, psychological factors or environmental factors.

What Are the Different Types of Industrial Fans?

Industrial Blowers: They are large and can cool and ventilate vast areas. They are lightweight and often come fully assembled. They are used in commercial setting, on farms, or other large places where people work.

Industrial Wall Fans: There are lots of reasons to buy an industrial wall fan. They are inexpensive, installation is a snap and they can be attached just about anywhere. They are best when used for concentrated cooling.

Industrial Floor Fans: Floor fans are free-standing units that are placed at floor level. They offer powerful airflow and are great for concentrated cooling. They are also very easy to move and are light. They often come equipped with carrying handles to make moving them around even more of a snap.

Industrial Pedestal Fans: Pedestal fans produce strong airflow but can be used in spots that cannot accommodate mounted fans. They come fully assembled. These fans are elevated on a high mount so they are great for cooling higher areas. They often come with adjustable heights. They are extremely adaptable.

Industrial Ceiling Fans: Industrial ceiling fans are much like residential ceiling fans. As one can guess, they are mounted to the ceiling. They are usually, however, built for function while design takes a backseat. They are quite utilitarian. You will often see them with steel guard enclosures around them and they are often much more powerful. However, many ceiling fan brands, including Westinghouse make industrial ceiling fans that are both beautiful and functional. You will need to mount this type of fan so be prepared to do that by reading our step by step instructions on how to install a ceiling fan.

Misting Fans: This type of fan works well in areas that lack central air conditioning. They can also be a great substitute when standard fans just aren't cutting it. However, they are not ideal for very large spaces. Misting fans are industrial fans which deliver fine streams of mist which cool and refresh the room and the people in it. They also help to settle dust particles which can plague industrial environments.

Five Reasons Why You Should Purchase an Industrial Fan:

1. They are economical and cost effective.
2. They are very powerful.
3. They are easy to install and are often portable.
4. They are great for creating a pleasant work environment. That means better morale and productivity amongst workers.
5. They circulate air and make the workspace cleaner, healthier and safer.

Article Source: http://EzineArticles.com/expert/Lilian_Gray/2026610