Particle Tech report - Edge runner mill and ring roll mill PDF

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Summary

Edge runner mill and ring roll mill...

Description

Bea U. Casiano

ENCH5B

7/8/19

CHE37: Particle Technology

EDGE RUNNER MILL & RING ROLL MILL Edge Runner Mill 

also called Roller Stone Mill

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crushes materials into fine powders by the rotating stones

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basic parts consist of two large rotating grinding wheels or stones turning slowly in a large bowl

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to start the mill, an electric motor in the base provides the power

Principle of Operation 

The size reduction is done by crushing due to heavy weight of the stones and the shearing force which is involved during the movement of these stones.

o The material to be grounded is put on the bed and with the help of the scrapper it is kept in the path of the stone wheels. o The material is ground for a definite period and then it is passed through the sieves to get the powder of the required size. Industrial Application 

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Foundry. Usually used for mixing of foundry chemicals, pastes, molding sand, foundry fluxes, food colors, etc. where an amount of binder or agglomerate is to be blended into the material. Also used for densification of the mix. The pan is stationary inside which rotate heavy duty millers/rollers. The heavy wide rollers ride over the material where intensive crushing, shearing and mixing action takes place. Scrappers and ploughs are provided for directing the mass into the path of the rollers. Pharmaceutical Application. Usually used for grinding all types of drugs to very fine particles but requires more floor space than the other commonly used mills.

Advantages & Disadvantages

ADVANTAGES  

  

Requires less attention during operation Various groups of elements and combinations of such elements produce a machine which operates with greater efficiency Utilizes less power Easy to clean Simple in structure

Illustration

DISADVANTAGES  

Not use for sticky materials Noise pollution

Ring Roll Mill Principle of Operation 

Large bulk materials crushed by jaw crusher to the needed size are fed into storage hopper by mine hoist and then fed into grinding chamber of main engine uniformly, quantitatively and continuously by electromagnetic vibrating feeder for grinding.

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The feed will be driven to the edge of the upper distribution dial by the centrifugal force, and fall down to the grinding ring where the material are repeatedly pressed ,crushed and grinded by the roller.

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It passes through the clearance between the grinding ring and the grinding roll where it is impacted, extruded, grinded and crushed.

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The high pressure air blower constantly inhale air from outside, the airflow with grinded materials go into classifier, the high speed impeller will screen the powder, coarse material is thrown to the split ring wall, back into the crushing chamber for re-grinding.

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When the double layer grinding machine works, the material is broken again by the gap between the second layers of grinding ring.

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Materials meeting the requirements of the fineness are blown into cyclone powder collector with airflow through pipelines for separation and collection.

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Separated airflow is back to blower through return duct on the top of the cyclone powder collector.

Industrial Application 

It is mainly used to grind and process variety kinds of non-flammable and nonexplosive materials with hardness less than 7 Mohs and humidity less than 6%. It is ideal grinding machine to grind and process the materials such as limestone, gypsum, barite, carbonate calcium, marble, feldspar, dolomite, granite, kaolin, bentonite, bauxite, etc.

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Ideally used for o Mining o Construction o Chemical industry

Advantages & Disadvantages ADVANTAGES

DISADVANTAGES

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Low investment cost

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o can crush, grinding, classifying, so the system is simple, and occupation area is about 50% of ball mill system. In addition, it can be installed outside, so it will reduce a large number of investment costs Low operation cost o High efficiency – roller compacted materials directly onto the grinding disc, so power consumption is low.Compared with ball mill, it saves energy consumption by 30% ~ 40% o Less wear and tear – as the roller are not in direct contact with the disc, and material of the roller and liner is high quality, so

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The input and output material balance should be monitored. Properly extend the downtime to ensure that the cavity is completely discharged. Limited to materials with a hardness not less than 7 and humidity not less than 6%.

life lime is long 

High drying ability o the hot air inside contacts directly with the material, drying ability is higher, and it saves energy o by regulating the air temperature, it can meet requirements with different humidity

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High classification accuracy o the internal grading device has the advantages of unique structure, good classification effect and no large particle pollution

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Stable and reliable work o the drive spindle of ring roller mill is driven by reducer, which has low energy consumption, high efficiency and high efficiency >96%

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High specific surface area o the particle surface area is occupied by a unit mass of the surface area

Illustration

ADVANTAGES  

   

Low investment cost Low operation cost o High efficiency o Less wear and tear High drying ability High classification accuracy Stable and reliable work High specific surface area

DISADVANTAGES   

The input and output material balance should be monitored. Properly extend the downtime to ensure that the cavity is completely discharged. Limited to materials with a hardness not less than 7 and humidity not less than 6%....