utilise Natural Frequency positive drive principle or the Free-Mass
principle. The "Natural Frequency" units are available
for heavy duty. Long stroke applications or where long conveyors are required.
"Free-Mass" designs are available for short-stroking,
constant headload applications or where short conveying distances are required.
"Free- Mass" design facilities variable feed rates.
Flow Promoting Devices:
Retrieval of materials from storage has been a problem since man began to produce more than he immediately consumed. Any material at rest tends to stay at rest. Man in general - and Karman in particular - has developed devices for overcoming this basic law of inertia.
Some materials will not flow satisfactorily - or at all - from a storage bin without a stimulating force. A naterial's flow is affected by:
- Moisture
- Partical Size
- Partical Size Distribution
- Partical Shape
- Cohesiveness
- Lenght of Time at rest
Any of these factors - or a combination of them can - cause material to "bridge" or "core" thereby shutting off flow. Once the flow has been started, it is desirable to take advantage of a material's static flow configerations, Plug Flow and Mass Flow.
Plug Flow
In a storage bin with Plug Flow configuration, the material flows
in a cylindrical column equal in diameter to the discharge diameter of
the bin. However, with a vibrating bin discharger the cylindrical discharge
column will be equal to the inlet diameter of the vibrating bin
discharger.
When the cylindrical column discharges, the peripheral material sloughs into the flow stream with eventual complete discharge.
Mass Flow
In the storagebin with Mass Flow configuration, the material tends
to flow uniformly throughout the bin, at the same velocity at any cross-section
of the bin. It is generally possible to develop Mass Flow in a
storage bin with a Plug Flow configuration, by:
- Increasing the angle of the bin's cone section, which increases the bin's height, or
- Using a vibrating bin discharger if the diameter of the storage bin permits.
are
generally recognised as the most effective means to increase active reclaim
from outdoor storage. They are being used for coal, salt, gravel, limestone,
wood chips, various raw ores and mine tailings. Unique patent features found
on no other units will give you the safest, most efficient movement of your
material from outdoor storage to other processing. The two specific drives
offered...
gyrated drive
whirlpool drive
Gyrated and Whirlpool Drives for Drawdown Hoppers:
Karman manufactures two types of Vibrating Bin Discharges -
as flow promoting devices.
- Gyrated with one-motor drive, and
- Whirlpool with two motor drive.
Gyrated Drive
Karman Gyrated Bin Discharger uses on heavy duty vibratory motor which
imparts and elliptical stroke pattern in a horizontal plane. The motor
normally operates at 1440 cpm, with a 2mm to a 3mm stroke.
This motion produces a shear plane between the bin bottom and the bin discharger. When combined with Karman's 30/60 cone design, all but the most difficult materials will be induced to flow.
Whirlpool Drive
The Karman Whirlpool Bin discharger imparts a unique, eliptical
"lifting-twisting" motion. This Dynamic Bin Discharger
utilises two heavy duty vibratory motors, mounted on 45 degree angles,
180 degrees apart. The motors operate at 960 cpm, and generate a 6mm
to 10mm stroke.
Vibratory motors mounted in this manner generate a lifting-twisting motion three dimensional motion, which moves the material in a whirlpool-like vortex. The lifting-twisting action take full advantage of the material's mass inertia to induce continous flow.
The Whirlpool Vibrating Bin Discharger is designed as the ultimate answer for super difficult materials such as dough mix, sticky filter cake, wet ore concentrates and sludges, long fibrous asbestos material and light density fibreglass bat material.
gyrated
whirlpool