Production Capacity Of Vibrating Screen

Vibro screen manufacturer will share this article with you.

The more products you plan to sort, the more surfaces you need to filter. The most immediate symptom of a screen that is too small is that its effectiveness is reduced because it cannot let so many particles pass through the holes.

On the other hand, the smaller the size to be sorted, the more surface is required, because the smaller the hole, the less the number of products that can pass.

Vibration frequency of vibrating screen

As a general rule for large classification, low-frequency and large-amplitude vibrations are best, while fine-classified high-frequency and small-amplitude vibrations are best. In other words, if the particle is large, a slow and wide movement is better, in this case the particle jumps are few but large, if it is small, it is smaller than many jumps but smaller. This is a problem that the particles do not pass through several single jump holes.

The importance of correct feeding

In the screen, as in any sorter, it is necessary to use the width of the entire work surface from the beginning. If the product falls on the screen surface "piled", the particles at the top of the pile will not touch the screen or the screening element until the pile is vibrated and disappears. When this happened, it had already crossed half of the earth's surface. In other words, we wasted the surface and caused a very important production loss. At the same time, the area where the piles are located will also be severely worn, and additional maintenance costs will follow. It also increases the risk of clogging, especially for low-density products, if the pile is much higher. This is meaningless, it is impossible to accept for correct screening.

This is why it is necessary to pay attention to the implementation and design of the pipes that dump the product on the screen, and use auxiliary means such as vibrating distributors when necessary.

Good screen and bad screen

A good vibrating screen must be reliable, minimize wear and maintenance, and have strong vibration like any vibrating screen: the more vibrating, the better, that is, the higher the production efficiency.

On the other hand, most "bad" screens are not really bad, but not suitable for use: if the product is wet and sticky, it will stick to the metal screening element instead of the polyurethane screen. If dry and fine, the screen should be dust-proof. If you are screening large and heavy particles, the screen should be very strong. If it is very sturdy and used with a good product, it will consume more power and maintenance costs than required.

The combinations are endless, and a good choice, suitable for use at the beginning, will save the user from having to remember this machine again in his life, or at least until he needs to install another screen.

The Importance Of Coal Washing

Coal washing is actually an important step in coal preparation. When washing the coal, non-coal materials and unnecessary raw materials are washed from the original ore. Through the coal washing plant, qualified products will be reached.

Why is coal washed(the importance of coal washing)?

The raw coal is mixed with many impurities during the mining process, and the quality of the coal is also different. The internal ash content of the coal is small, but the internal ash content is large. The products produced after coal washing process are generally divided into meteorites, medium coal, grade B clean coal, and grade A clean coal.

By washing coal, the cost of coal transportation can be reduced and the utilization rate of coal can be improved. Clean coal is an energy source generally used as fuel, and the fine coal in bituminous coal is generally used for coking.

The main reasons for coal washing are as follows:

1. Improve coal quality and reduce coal pollutant emissions

Coal washing can remove 50% to 80% of ash and 30% to 40% of total sulfur (or 60% to 80% of inorganic sulfur) in coal. Burning coal can effectively reduce soot, SO2 and NOx.

Emissions, washing 100 million tons of thermal coal can generally reduce 600,000 to 700,000 tSO2 and remove 16Mt of meteorites.

2. Improve coal utilization efficiency and save energy

The improvement of coal quality will significantly increase the efficiency of coal utilization.

Studies have shown that: coking coal ash content is reduced by 1%, iron-making coke consumption is reduced by 2.66%, and iron-making blast furnace utilization rate is increased by 3.99%; the use of washed anthracite to produce ammonia can save 20%;

For every 1% increase in coal ash used for power generation, the calorific value will decrease by 200~360J/g, and the standard coal consumption per kWh will increase by 2~5g; when industrial boilers and kilns burn coal, the thermal efficiency can be increased by 3%~8%.

3. Optimize product structure and improve product competitiveness

The development of coal washing is conducive to the transformation of coal products from a single structure, low quality to multiple varieties and high quality, and to achieve high-quality products.

There are many coal consumers in my country, and the requirements for coal quality and variety are constantly increasing. In some cities, the sulfur content of coal is below 0.5% and the ash content is below 10%.

If coal is not developed, it will not be able to meet market demand.

4. Reduce production waste

Because the coal-producing area is far away from the economically developed and rich coal resource areas, the coal transportation volume is large and the transportation distance is long.

The average transportation distance of coal is about 600 kilometers. After washing, the coal can remove a large amount of impurities and wash 100Mt raw coal, can save 9600Mt-km capacity.

What Is a Vibrating Screen?

Also referred to simply as a screen, a vibrating screen consists of a vibrating chassis that supports one or several surfaces or screen elements inside.

The screen serves to classify different particle sizes from bulk products in a continuous process. The inlet material (raw material) is pushed from the part where the screen is fed to the other end, and the particles are separated according to their size, shape or density. There is also a vibrating screen loaded by the center, and the product moves in the radial direction to the outer output.

For the correct advancement of product, the process must be continuous. If the screen surface is horizontal, it is due to vibration. Most screens have a certain inclination, and the advancement of the product is due to a combination of gravity and vibration.

Screening element

The screening element is a flat surface or a slightly curved surface with perforations of a certain size, so that when the product is poured in bulk on the element, it only passes through those particles whose size is smaller than the perforation size.

The screening element can be a metal or nylon wire mesh, passing through a rod between the materials, a metal sheet with circular, square or hexagonal perforations, or a more or less hard rubber or polyurethane perforated sheet.

The type of element is selected according to the application, nature of the product, the size and shape of the particles, abrasion resistance, adhesion, humidity and temperature.

A screen can have several screen elements on the top of each screen to form different floors. In this case, the floor with larger holes is placed on the upper part, while the members with smaller and smaller holes are installed in turn on the lower floor slab. In this way, each particle is trapped between the floor where the cutting point (opening) is larger than the particle and the floor where the cutting point is smaller.

Screening efficiency with vibrating screen is much higher

The traditional non-vibrating screen is composed of a fixed mesh with a large inclination angle. When vibration is introduced, the product vibrates and the particles jump on the screen surface without sliding. Each jump is an attempt by a particle to pass through a hole. If the machine vibrates, the probability of this happening is much greater. In other words, the effect is much greater.

When a particle jumps and falls again, it can do so in a hole or an area without holes. If the screening element is a wire mesh, the particles can fall on the wire or on another particle without squeezing through the hole through which it should pass. This is why the efficiency without a screen is 100%, because it requires an infinite number of jumps, so that all smaller particles, that is, holes, will leak.

The concept of screening efficiency is very clear: it is the weight of the particles actually filtered through the holes divided by the percentage of the total particles that should be sieved.

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