Metal and Paints Testing Instruments

The ROLL CRUSHER is a rugged slow-running machine used for pre-crushing lumpy material prior to further immediate processing or finer grinding. The Single Roll Crusher can process up to 10 tonne per hour to an end particle size ranging from “walnut” to “hazelnut” dimensions, although output and the degree of fineness depends on the material being crushed. Friable materials, for example, are reduced to a much smaller size.

Applications abound in the chemical, foodstuff, pigments and pharmaceutical, coal and agrochemical industries.
The de-lumping feature greatly enhances flow of materials between processes.

A DOUBLE or MULTIPLE ROLL CRUSHER is specified where larger material lumps are to be reduced. This option has a greater “live-bed” crushing area. The Double or Multiple Roll Crusher is fitted with two or more roller shafts running at differential speeds. The shafts can be specified to run either inwardly or outwardly.

TYPICAL USES

• การบดเรซินก่อนการละลาย (Pre-crushing of resins prior to dissolving)
• การบดเม็ดสี (De-lumping of pigment prior to dispersion)
• Reduction of damp and caked materials
• การแยกเม็ดพลาสติค (Separation of agglomerates of plastic granules)

CONSTRUCTION
The rugged welded housing is box-shaped and accommodates either single, double or multiple roller shafts, the crushing cams, the crushing combs and the stripper combs. It is designed to produce little or no dust. Models are available in normal carbon,acid resistant stainless steel, hastelloy and wear resistant steel.

The crushing cams of cast steel are mounted on the roller shaft in staggered positions, accurately spaced so that they pass between the crushing and stripping combs which are mounted laterally on opposite sides of the inner housing. Both sets of combs are identical in design but have different functions according to the direction of rotation. Different-shaped crushing elements are available, depending on whether the material is hard, brittle, viscous or moist. Screens can be fitted for special applications.

OPERATING PRINCIPLE
Feed material is introduced to the crushing area by hopper, feeder or directly from a previous process. The crusher can be choke fed and is therefore ideal for silos and spray towers.

The material is seized by the rotating crushing cams and broken against the crushing combs until small enough to pass through and out of the machine. Fine particles included in the feed-stock fall through the combs without being crushed. If certain materials cause a blockage, the rotating shaft automatically reverses its direction, temporarily, to free the material. The bearing plates at both ends of the housing accommodate the roller bearings, protected by radial seals, in which the shaft rotates. The shaft apertures in the end plates are protected by PTFE seals pressure-proofed to 0.5 bar, IP54. The second shaft on the Double or Multiple Roll Crusher is driven by grease-lubricated gear wheels on the outside of the housing.

The maintenance requirements on the Roll Crushers is minimal. The crushing cams, crushing combs and stripper combs are easily removable for cleaning.

The below standard crushers are driven by a hollow shaft worm reduction unit with an integral torque limiter from a flange mounted motor.
The torque limiter has the ability to stop rotation of the crusher shaft whenever the stall torque exceeds the calibrated value, thus safeguarding the transmission components if hard tramp material enters the crushing chamber. These units are ideal for fitting into
process lines and are held on by the inlet and outlet flanges and therefore do not require any bulky support frames.

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

The 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.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 arm.

Smooth door and chamber linings are also available; these are interchangeable with the standard grooved linings and are especially suited for use with most friable materials, such as soil, where grinding efficiency is unaffected by the absence of grooves but with the advantage of easy cleaning.

Interchangeable screens, with different hole diameters, determine the fine particle size. The bulk of the ground product is reduced to a size much finer than the screen hole. 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:

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 (see table below):
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 can be fed into the mill by means of a vibratory feeder fitted above the hopper. Output varies according to the nature of the product and the screen mesh sizeFEATURES

Interchangeable screens, with different hole diameters, determine the fine particle size. The bulk of the ground product is reduced to a size much finer than the screen hole. 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:

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 (see table below):

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 come in cast iron and stainless steel, and beater tips in chrome, steel, and stainless steel and chrome free. There is also a special unit with smooth liners for soil grinding that offers fast cleaning and minimizes cross contamination. 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.

Options include all-stainless steel contact parts, flameproof electrics as well as special hoppers and stands.

SAFETY FEATURES

MOTOR
The mill is powered by a 1.1kW 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 (approximately):
113cm H x 56cm W x 70cm D
52kg nett, 62kg gross

Samples arriving in the laboratory often require pre breaking before they can be processed in secondary fine grinding mills; the Laboratory Jaw Crusher is ideally suited for this operation.

These rugged units are capable of crushing the most tenacious of materials; concrete, glass, granite, limestone, ores, quartz, slag and stones.

Normally floor standing units, the Jaw Crushers come as standard with a sample collection tray, they can also be mounted on a frame to accommodate larger containers or fitted into a small pilot plant scheme.

Material is fed into the carbon steel inlet hopper from where it cascades down into the crushing jaws. The action of the eccentric shaft together with the single toggle action both crushes the material and draws it further into the jaws. Output size is determined by the adjustable gap at the bottom discharge end of the jaws.

Standard units are supplied with cast manganese steel jaws and stainless steel lateral wear plates, tungsten carbide and stainless steel jaws are also available and the smallest bench top version can be fitted with Zirconia jaws for non metallic contamination.

Over the years we have supplied many special units with corrosion resistant linings and an all stainless steel version with tungsten carbide jaws for the nuclear industry.

A comprehensive range of ball mills for laboratory and pilot plant offers the operator a flexible approach with a wide choice of pot sizes and materials. From a single pot to multi-tiered units capable of accommodating 35 litre containers you can be sure to find a mill to suit your requirements.

• Many models available with variable speed
• Flameproof units for hazardous areas
• Wide choice of accessories include screens, pourers and tipping stands for straining the contents of the mill pot
• Pots available in carbon steel, stainless steel and porcelain

Various different types of grinding media can be used to obtain maximum grinding efficiency. For the ceramic pots steatite or high density alumina balls are generally used whilst for the steel pots either carbon or stainless steel balls are the normal choice. Other media such as zirconia cylinders or glass balls can be supplied to order.

The SWING HAMMER MILL is possibly the most economical mill available for the return in output. Glen Creston offers two versions of the mill, each available in three sizes – Models 10, 20, 30 and 60:-

Bottom Discharge, for discharge of material by gravity.

Bottom Discharge, for efficient discharge of lighter weight particles, such as paper, plastic foam or feathers and, possibly, for applications where the processed material is distributed to another processing area or level.

As a further option, each unit can be supplied either on a steel baseplate, for customer installation and wiring, and for positioning over a collecting vessel, pit, conveyor or hopper; the bottom of the mill is open for rapid discharge, or free standing, on a frame, ready-wired with an integral starter; the outlet has a grid to prevent hand access.

OPERATING PRINCIPLE

Bottom Discharge Mill
Material is fed into the carbon steel inlet hopper, protected by safety baffles, from where it falls into the grinding chamber and
is ground by the action of freely rotating hardened steel hammers against a serrated face. The ground product passes through a mild steel screen.

Blower Discharge Mill
The operating principle is the same as for the Bottom Discharge Mill but, additionally, a powerful fan pulls the material into the grinding chamber and through the screen.

MILL FEATURES THAT BENEFIT HUNDREDS OF USERS

• Low cost
• High throughputs
• Low Power Consumption
• Simple, robust design
• Large inlet hopper – ideal for bulky material
• Compact size
• 180? full-width screen area
• Easily interchangeable screens, available in mesh sizes 0.5mm to 30mm (One standard screen of customer’s choice is supplied with each mill)
• Hammers have 4 grinding edges, each of which can be used in rotation, for maximum service life.
• Serrated liner in top section of mill for increased milling efficiency
• Durable mill body constructed from cast steel

OPTIONAL ACCESSORIES

• Magnet, which attaches to inlet chute to attract tramp ferrous metal
• Product/air separator, comprising duct, cyclone, sack filling neck with clamps and support (for Blower Discharge version only)

Glen Creston project and design team will be pleased to quote for special electrics and accessories, such as frames and chutes, to customers’ individual specifications.

	Model 10	Model 20	Model 30
Recommended Operating Speed	3650 rpm	3650 rpm	2750 rpm
Floor Space Required	91cm x 104cm	91cm x 117cm	99cm x 142cm
Power required for Bottom Discharge	2.2kw	4.0kw	7.5kw
Feed Opening Size	15.2cm x 15.2cm	23.6cm x 15.2cm	30.5cm x 15.2cm
Maximum Throughput kg/hr depending on material and screen size	1000	2500	5000
Screnn Area	640.8cmz	965.2cmz	1286mz
Motor	TEFC single-phase 230V 50Hz or three-phase 400V 50Hz mounted on heavy steel motor rails, complete with belt drives, guard and starter. Protection IP54

For high-speed uniform grinding to analytical fineness of wet and dry samples, from rocks and minerals to ceramics and cement.

Precision sample preparation for XRF and AA analysis as well as for geological/mineral assay work.
Batch grinding from 1cc to 250cc samples

Three vibration amplitude settings

Most samples ground to analytical fineness in 1 to 3 minutes

Suitable for a wide range of grinding dishes, from the most fragile to the
hardest and heaviest

Negligible contamination The British-made GYRO MILL is the perfect choice for rapid, homogeneous and reproducible grinding of samples, both wet and dry. It is widely used in geological/mineral assay work for sample preparation as well as for wet chemistry and instrumental analysis, such as XRF spectroscopy.

Materials routinely ground by this method include brick, castings, cement, ceramics, chemicals, clinker, coal, coke, concrete, ferro-alloys, fertilisers, fluxes, glass, iron, limestone, minerals, paint, pesticides, pharmaceuticals, dried plant material, ore, precious stones, rocks, metals, sand, slags, silicates, soil, steel, wood…

The GYRO MILL is particularly recommended for grinding smaller samples from 1cc to 250cc. Typically, the maximum initial particle size is approximately 12mm, depending on hardness of the material.

GRINDING INTENSITY CONTROL
The GYRO MILL has a positive advantage over many other dish and puck mills
in that the grinding intensity can be adjusted to one of three settings.

Amplitude adjustment ensures the best possible results, since it can be set to complement the special characteristics of the feed material, the fineness required, the wear rate of the dishes and the degree of contamination from the grinding dishes which can be tolerated. By selecting the optimum combination of amplitude and timer settings, precision particle size distributions can be achieved and reproduced.

HORIZONTAL GRINDING ACTION
A further advantage is that it is designed to ensure a smooth, horizontal grinding action with minimal vertical vibration. The puck and rings are larger and have greater height than those in conventional dish and puck mills. Consequently, they avoid ‘bouncing’ off the lid and base of the dish in a vertical direction, minimising excessive wear in these areas together with unnecessary sample contamination.

WORKING PRINCIPLE
The GYRO MILL uses a fixed-speed, standard motor coupled to a flexible drive shaft. Two eccentric weights mounted on the drive shaft transmit a horizontal gyratory vibration to the sealed grinding dish clamped into position on the mill. The vibration causes the puck and one or two rings in the dish to rotate freely, crushing the sample.

Grinding performance is easily controlled by a patented mechanism which adjusts the position of the eccentric weight in relation to each other, allowing three possible grinding intensity amplitudes. With maximum overlap of the weights (‘high setting’), the largest amplitude is achieved; with minimum overlap (‘low setting’), the amplitude is at its smallest

ADVANTAGES

• Large puck and rings result in high intensity grinding with high percentage of fines
• Easily adjustable grinding intensity/vibration amplitude control with three settings
• Variable, built-in process timer
• Accommodates the whole range of grinding dishes, of whatever manufacture, from the most fragile to the hardest
• Negligible sample contamination
• Cam clamping device allows rapid, simple loading and unloading of dishes
• Sound-proof cabinet
• Maintenance-free
• Manufactured in the UK to the highest standards
• Timer switch, stop/start switch, overload relay and cover safety switches

‘LOW’ gives an amplitude of approximately 10-13mm; the most gentle movement for grinding with the least amount of contamination or when using fragile grinding dishes, such as agate.

‘MEDIUM’ gives an amplitude of approximately 13-17mm; recommended for most grinding applications not involving fragile dishes.

‘HIGH’ gives an amplitude of approximately 17-19mm; for ultra fast grinding or for crushing very hard samples.

EXCEPTIONALLY FAST GRINDING
In our test laboratory, using a 100cc tungsten carbide grinding dish, with grinding intensity set at ‘high’, please see the table below for results which were achieved with the GYRO MILL.

TECHNICAL DATA
Motor : 0.4kW 230V single-phase 50Hz or 400V three-phase 50Hz
(other voltages or frequencies can be supplied on request)

Net weight : 275kg (approx.)

Dimensions : 64 x 64 x 107cm high