Tuesday, April 29, 2008

Grease Table




GENERAL

The Armstrong Grease Table is a relatively light weight, large capacity machine with a large water recovery and temperature control system.

REQUIREMENTS

For efficient grease recovery the following factors must be adhered to:

  1. Only good quality grease must be used. Diamond test the grease before regular use.

  2. The spray water and the grease must be of the right temperature (22-24°C)

  3. The spray water must be clean and contain less than 100ppm solids.

  4. The spray water must contain less than 10ppm combined Na and Mg.

  5. The material fed over the grease screen must be correctly sized i.e. 1-2mm, 2-4mm, 4-8mm, 8-16mm, 16-32mm fractions or smaller. This is so that the largest non-diamond particles in the size fraction will not dislodge the smaller diamonds. Larger non diamond particles will also force smaller non diamond particles into the grease if the variation in particle size is too great.

TECHNICAL DETAILS

The grease screen consists of a 1.5mm stainless steel mesh screen tightly suspended between an outer steel frame. The two vibratory motors are fitted to the sides of the frame which allows the water from the spray bars to pass directly into the underlying water tank for re-circulation. The water tank is fitted with baffles to allow for sedimentation and should be cleaned at regular intervals to prevent the build up of solids in the water. The water tank is fitted with a heater element and thermostat to control the water temperature to within the required limits.

OPERATIONAL DETAILS

Grease is applied with a spatula from underneath the screen through the screen cloth between the screen bottom transverse support bars in segments 2 and 4. Sufficient grease is forced through the screen so that the grease protrudes to 1-3mm above the screen. The grease is then smoothed over the surface as required to form a thin layer of grease on top of the screen. This thin grease layer together with any diamonds is easily removed with a spatula to leave a clean remaining layer of grease on the screen surface. Further grease is then forced up through the screen cloth using a spatula to form a new clean layer of grease 1-3mm thick as described above.

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