Glen Creston Ltd
Cross Beater Mill

For crushing soil, bricks, concrete, rock, cement clinker, coal, glass, ores, minerals, rare earth products, chemicals, spices, grain and hundreds of other materials up to medium-hard range.

• 200gm to 50kg/hr
• Feed size up to 30mm
• Coarse, medium or fine grinding
• Linings available in cast iron, chrome steel and stainless steel

The deservedly popular Cross Beater Mill is used for crushing and grinding a wide assortment of materials up to the medium-hard range, within a variety of industries, including construction, environmental, mineral, chemical, agricultural and ceramic. The mill is remarkable for combining small size with strength and power for heavy duty application and continuous operation.

Controlled by a regulator material passes from the hopper into the grinding chamber, where it is pulverised between the hard grooved door and chamber linings, as well as by the impact of the three rotating beater tips on the beater arms.

The mill processes samples from 200 grams up to a maximum of about 50kg/hr, with an initial lump size of up to 30mm down to a finest end particle size of approximately 50 microns. For continuous throughput, material is fed into the mill by means of a vaibratory feeder fitted above the hopper. output varies according to the nature of the product and the screen mesh size.

Interchangeable screens, with fourteen different hole diameters, determine the final particle size. The bulk of the ground product is reduced to a size much finer than the screen holes. For example, when grinding friable, medium-hard substances using a 0.5mm screen, the approximate percentages which pass through the following BS mesh sieves are:-

• 100% through BS mesh 72 (0.212mm)
• 98% through BS mesh 85 (0.18mm)
• 95% through BS mesh 100 (0.15mm)
• 70% through BS mesh 150 (0.106mm)
• 40% through BS mesh 200 (0.075mm)

Screens are changed quickly and simply by sliding them in and out of the recess provided. They are available in stainless steel with the following hole sizes:- 0.12, 0.2, 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0 and 10mm, and in heavy duty carbon steel with hole sizes:- 6.0, 8.0 and 10mm.

Construction
The housing is of heavy duty cast iron. The grinding chamber lining and door lining are available in cast iron, chrome steel and stainless steel, beater arms in cast iron and stainless steel, and beater tips in chrome steel and stainless steel. cast iron is the hardest of the three, the least expensive and most frequently used. Chrome steel is usually selected for grinding abrasive materials. stainless steel is used for applications demanding improved chemical resistance, as well as for food and pharmaceutical applications.

Safety Features

• A stainless steel cross-bar is fitted across the top of the feed hopper, restricting hand access but allowing unobstructed passage for the product.
• The mill cannot be switched on untill the door is fully closed.
• A brake motor, operated by a fail-safe micro-switch, brings the beater arm to an instant halt if the door is opened during operation.
• A specially designed outlet chute prevents access to moving parts from underneath, even with the screen removed.

Other Features

• Beater tips can be resharpened and their position can be re-adjusted to maintain performance
• The mill can be stand-mounted or bolted to a bench
• A 5-litre receptacle with filter tube and clamps is included
• A 30-litre receptacle is available as an optional accessory (customers' own containers or sacks can be attached, if required)
• Dust-free and easy to clean

Motor
The mill is powered by a 1.1 kW 3000 rpm motor, supplied for use on single-phase or three-phase power supplies. (other voltages can be supplied on request.) An integral mill-mounted push button starter and motor protection device are fitted as standard.

Dimensions & weight of mill, stand-mounted (approx.):- 113 H x 56 W x 70cm D.

52kg nett, 62kg gross.

Sample Mixer Mill M. 280

• Fast, accurate sample preparation to the most stringent requirements of analytical spectroscopy and analytical chemistry
• Ultra-fine grinding and homogenous mixing, dry or wet
• Grinding and mixing containers available in Alumina, Agate, Polystyrene, Hardened Stell, Tungsten Carbide and Zirconia

Advantages

• The M. 280 has been an industry standard for more than 30 years
• Also used for blending, diluting, dispersing, emulsifying, etc
• Completely uniform distribution of constituent components is achieved so that even the smallest part will be truly representative of the whole
• The entire sample can be recovered - there are no losses during grinding or mixing
• Strict control over contamination; introduction of abraded particles is reduced to the very minimum and kept under control by the choice of appropriate grinding and mixing containers
• Dust-proof due to the use of closed containers, hence often used for toxic, irritant and radioactive samples
• Grinding capacity from about 1 to 10ml
• Mixing capacity from about 1 to 50ml. (for volumes larger than 50ml, we recommend the TURBULA Shaker-Mixer)

Size: 38 x41 x 30cm
Weight: 24kg (net), 29kg (gross)
Power: 220/240V, 50Hz, 1/3 h.p. motor

Operating Principle
Grinding and mixing takes place in sealed containers, shaken at high speed in a three-dimensional figure-of-eight motion. The violent and complex movement in three mutually perpendicular directions is repeated 1,000 times per minute. Dimensions of the containers are calculated to take full advantage of these displacements and the resulting high grinding energy.

Mixing is usually carried out without the addition of ball pestles. The homogeneity achieved satisfies the stringent requirements of spectroscopy, x-ray diffraction studies and analytical chemistry.

For grinding, one or two ball pestles are added, which crush the material by impact. The distance of travel in each direction, the speed and dimensions of the container are correlated in such a way that the ball travels along the entire axis of the container and, with each movement, strikes a different portion of the substance.

Continuously adjustable jaws on the container clamp can be easily opened and closed to allow the use of various sizes of grinding and mixing vessels, from 45mm to 80mm in length and up to 57mm in diameter. Containers smaller than 45mm can be held by suitable inserts. With the appropriate adaptor, as many as seven smaller samples can be run at one time.

The machine is supplied with a push button, 30 minute resettable timer to ensure reproducable running times and comparable results. The mill's sheet metal housing is coated with chemically resistant paint, and vibration-absorbing mounting allows quiet bench-top operation. The M. 280 incorporates all current safety requirements.

Grinding and Mixing Containers for the M. 280

The grinding containers should be harder than the material to be ground and of a substance which will not interfere with the subsequent analysis.

Handling a sample always contaminates it. the key to a successful interference-free analysis is to handle the sample so that contaminants are predictable, are present only at very low levels, or are not elements sought by the analyst.

Grinding containers are available in a wide selection of materials - alumina, agate, hardened tool steel, stainless steel, tungsten carbide, zirconia and (particularly for mixing) polystyrene, which precludes metalic contamination.

Containers for the Sample Mixer Mill M. 280

Price		£850.00	£420.00	£910.00			£920.00	£340.00
Container Material	Hardened Tool Steel	Tungsten carbide	Alumina	Agate	Polystyrene	Polystyrene	Zirconia	Hardened stainless Steel
Catalogue No.	27-296	27-298	27-297	27-299	27-286	27-287	27-8005	27-8007
Diameter	57mm	57mm	57mm	57mm	33mm	54mm	63mm	57mm
Length	76mm	60mm	70mm	70mm	76mm	63mm	68mm	76mm
Balls: No. & Dia.	2 x 12mm 4 x 6mm	2 x 11mm	1 x 12mm	2 x 12mm 2 x 9mm	not included	not included	2 x 12mm	4 x 12mm
End-caps	Screw-on, steel	Screw-on, tungsten carbide	Slip-on, alumina ceramic	Slip-on, agate	Slip-on, polyethylene	Screw-on, plastic	Slip-on, zirconia steel	Screw-on, stainless
Volume (approx.)	65ml	50ml	40ml	40ml	65ml	135ml	45ml	65ml
Grinding Capacity (max.)	10ml	10ml	8ml	8ml	-	-	8ml	10ml
Mixing Capacity (max.)	25ml	25ml	20ml	20ml	30ml	50ml	20ml	25ml
Wet Grinding/ Mixing	#	#	*(1)	-	# *(2)	#*(2)	-	#
Dry Grinding/ Mixing	#	#	#	#	#*(2)	#*(2)	#	#

*(1) Wet grinding/mixing is possible with special clamp 27-8015
*(2) Generally used for mixing only. However, certain soft substances can be ground in polystyrene containres.

Dust/liquid seal between cylinders and end caps is effected by 'O' rings or gaskets.