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Shaoxing Sanhe Powder Co.,Ltd
Address: Haoba Cao'e street outside the village of Artemisia
Phone：13505857150
E-Mali：donghuichina@163.com
Q Q：504059063
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Technical |
Current position： Home > Technical Data |
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difference between disk mill grinding collision
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Currently there are several manufacturers of flat-jet mill called disk mill.
The difference between disk mill and I produced a fluidized bed
opposed jet mill, a lot of users do not know, letters, calls to ask, for which
I have the honor to disk mill and fluidized bed opposed jet mill difference Profile as follows:
1, from the jet mill development perspective: the idea of
the impact of the use of the energy flow as early as the 19th century
crushed generated. 1882 U.S. Gosling (Goessling) presented his
first paper on the use of kinetic energy to smash the patented
airflow. 1936 Andrew (Andrew) proposes not only to be crushed
and pulverized particles can be graded according to the size of its
own patented flat jet mill. Click patents in the United States for the
first time to create a product 名叫邁克勒奈 Zell (Micromizer) flat jet mill.
Known as the world’s first generation of jet mill.
This type jet mill in the country from 60 to over 70 years manufacturers.
World, since the application of the flat jet mill, scientists from various countries
and companies were constantly improved work has appeared in the circulation pipe
air grinder, single air jet mill, air jet mill, and so on. Until the eighties, the German company
Al plate (Alpine AC) introduced a fluidized bed opposed jet mill (Fluidized bed opposed jet Mill),
to solve the flat grinding mill due to the high hardness (Mohs hardness 5-10) materials, mill body
lining wear problems. This fluidized bed opposed jet mill is characterized
by: no lining can grind various hardness products; very low mechanical wear rate;
product is not contaminated, you can achieve the most fine-grained d97 = 2.5-90μm,
system a senior finished; ideal particle size distribution with specific;
no coarse particles; very low noise, is the world’s most advanced grinding equipment
for third-generation jet mill.
2, from the jet mill grinding principle point of view, there is a big difference between the two jet mill:
Flat disc jet mill grinding principle:
Pressure gas is formed by feeding high-speed jet injector spray material, the grinding material
is injected into the grinding chamber,
grinding chamber periphery toward smash mouth smash room directional airflow jet speed,
so that the material produced between fierce collision, friction, shearing cut thereby be crushed.
Pulverizing chamber at high velocity gas stream to form a strong swirling flow, the centrifugal force
generated by high speed movement of the powder particles in the grinding chamber periphery,
when pulverized to a particle size classification particle size is less affected by the centrifugal force
due to reduced airflow to the heart, from the classification swirl, the center exit into the collection system.
The crushing principle of fluidized bed opposed jet mill are:
The high-pressure gas through a nozzle to accelerate to supersonic supersonic (approximately 2 times
the speed of sound) airflow incident on the smash hit areas, so that the material
fluidized. Material particles are accelerated under the action of high-speed airflow
fostered tremendous kinetic energy, occurs at the intersection of
the jet nozzle mutual impact of the collision, to achieve the purpose of crushing.
With the material to be crushed is transferred to classification zone updraft, the
area in the hierarchical level of the turbo unit ultrafine broken desired fineness
of the material selected for the cartridge to be collected by the collecting cyclone
efficiency. Pulverizing and classifying the powder in the same cavity at the same
time, greatly improving the efficiency of powder pulverization and classification.
Crushing and grading on the principle point of view, there are the following differences:
1, crushing cavity pressure and velocity distributions are different:
Flat mill is crushing cavity center of pressure and velocity pressure and velocity
at the minimum and maximum crushing walls.
Collision mill is crushing cavity center of pressure and velocity pressure and
velocity maximum and minimum crushing wall.
Therefore, the former two-phase (ie solid and powder flow vapor) on the wall
erosion, abrasion walls,
the purity of the powder finished lower, the greater the hardness of the
material, this phenomenon is more serious. At present, some in the cavity plus
the lining, but the problem still exists, especially for crushing high hardness
(Mohs hardness of 8.5 to 10) of the material. Mill and the mill the collision wall wear,
high hardness material is more suitable for crushing, while maintaining a high purity material.
2, the energy of the collision mill supplied by the gas almost all materials
used in the short-range acceleration, high crushing capacity, a flat grind
is catching impact,
by the impact of the speed difference to crush the material. However,
residual energy after a collision material (speed) is not good use.
Therefore, the corresponding lower grinding capability, but there is
a large portion of the residual energy of the collision can be used to
re-pulverization, the other part on the ability of high speed rotation is
consumed to maintain the material. Under the same conditions,
the collision can wear flat ground to less than about 30%.
3, due to the principle of flat grinding classification: classification zone
depends mainly on grains of powder particles of centrifugal force, centripetal
force and suction air flow synthesis grading, classification accuracy depends
on the stability of the flow field, and flat grinding mill area of classification
affected zone is large, unstable air flow field, therefore, classification accuracy
is poor; while colliding with high-speed rotating grinding wheel set device to
control hierarchical classification
accuracy in the classification zone, so high classification accuracy, narrow
particle size distribution of powder . |
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