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Papermill Equipment

Pulleys, Sprockets & Gears

Mill Hill heavy Engineering Ltd.’s Driveline Division was established 8 years ago to cater for drive spares supply to paper mills and later to power transmission dealers and stockists throughout the country. All manner of drive products from pulleys and sprockets to gears and couplings can be designed and manufactured in house to customer requirements. Please find below a selection of some of our products that are available.

We can manufacture pulleys of all descriptions including Poly–V pulleys, V-Belt pulleys, Flat Belt Pulleys in both Metric and Imperial sizes. Bores can be made either to suit Taper-Lock bushes or Parallel with keyways to suit customer requirements. Pulleys can be ordered in any quantity, material and size up to 3800mm in diameter. All pulleys are manufactured in accordance to BS 3790 / ISO 4183.

Sprockets can be supplied for all simplex, duplex, triplex and multiplex chains up to 3” Pitch. These are made to order in Cast Iron or Steel and are available with a Pilot Bore or Taper Bore as per customer requirements. All of our sprockets are manufactured to BS / ISO standards with ANSI standards also available.

We offer a full service to industry from inception through to CAD Design work through to machining, fabrication and installation on a wide range of engineered products. We can work with most materials to suit customer requirements on all pulleys and sprockets up to 14’ 0 Dia with a raw material weight of up to 20 Tonnes.

Pulpers

Pulpers are available in sizes from 6’ to 24’ diameters for low, medium and high consistency pulps in continuous or batch production.

A pulper is a sturdy stainless steel tub, incorporating 4 baffles that aid the agitation of the stock, and prevent mass rotation. A stainless steel 8 bladed rotor is used for most applications, but medium or high consistency rotor can be used. the 8 bladed rotor is designed to rotate with minimal clearance above the screen plate, forcing stock through it. Fibres too large to pass through are cut by attrition between the rotor and screen plate bars to be accepted. Large impurities are retained in the pulper tub to be removed by pulper cleaning equipment. 

The pulper tub and baffles are fabricated in 8mm thick stainless steel, with three external RSC strengthening rings reinforcing the tub. All other contact parts are stainless steel. All rotors are mounted on forged EN8 hubs that are carried on an EN8 driveshaft, mounted on spherical roller bearings, housed in a heavy duty fabricated mild steel cartridge. The whole assembly is mounted on a robust mild steel leg assembly, giving a stable platform for pulper operation. A motor base plate incorporating a jacking arrangement and V-belt sheaves are designed to give optimum operating speeds from a customer motor. 

Pulper Drive & Rotors

Conveyors are generally of an overlapping steel slat apron design, although this is subject to customer duty requirements.  The slats are bolted to link attachments, carried on 60,000 lbf breaking strain, solid bearing pin chains. The conveyor chain framing is extended upwards to carry slat aprons, preventing loose material spillage.  
The conveyor tail and framework incorporates heavy duty take-up units for chain tensioning.  The driveshaft is mounted in spherical roller bearings and is driven via a helical/bevel gearbox and Duplex chains.  On wider slat units, central supports carrying high density wear strips are provided.

For higher consistencies, 15% - 20%, a high consistency is required. This is an independent rotor, incorporating intense shear forces to defibre the stock, The rotor is designed to drag stock to the base of the pulper tub and throw it to the sides, resulting in stock agitation, which causes fibre to fibre shearing, High consistency pulping is used with de-inking applications, since no fibre shortening occurs and the high shear forces rub the ink particles from the fibres. 

Rotary Separators

The Rotary Separator is a Highly efficient Screen secondary Pulper for processing waste papers. working in conjunction with continuous Pulpers. In this process the waste based pulp leaves the Pulper through an extraction plate with coarse holes. 
Impurities such as polystyrene, small pieces of plastic. paper clips, staples etc pass with the stock to the Rotary Separator and are discharged separately as lightweight and heavy contaminants. In addition to the separation and removal of light and heavy rejects the Rotor and Screen plate deflakes the stock and the accepted fibres pass through the Stainless steel screen plate mounted behind the Rotor. 
The centrifugal separator body and hinged door are of fabricated Stainless Steel construction to withstand the high attrition rate of the heavy rejects within the unit. The extraction chamber is fabricated in Stainless Steel. 
The centrifugal separator is designed with a retractable drive cartridge and Rotor assembly making access to the screen plate and Rotor for maintenance purposes extremely easy, removing the need for lengthy machine downtime. 
Rotor clearance is achieved by external adjustment of the drive cartridge, eliminating the need to dismantle the machine. 

Reversing Trommel

Trommels screen the stock by size, effectively removing all medium and coarse impurities. Influent is introduced into the rotating perforated drum, incorporating an internal double helical flight that conducts the materials to the back of the drum where internal sprays, together with the tumbling of the rejects, ensure effective separation of fibrous materials. These pass through the perforated drum into the accepts vat to be either returned to the pulper, or forwarded through the system. After a pre-determined amount of time, the drum reverses, and with the aid of helical flights, fully empties the rejects from the Trommel for disposal.
Drum perforations vary depending upon furnish and application.
All contact surfaces are stainless steel and the drum splash hood and accepts catch tray are mounted on a robust mild steel base frame. The drum is driven via a helical/bevel gearbox and carried on a spherical roller bearing at the rear and two guide wheels at the front 

Vibrating Screens

The VJ500 and VJ1000 vibrating screens are used for the cleaning of both high and low consistency stocks to remove heavy and light contaminants, and for the secondary screening of materials rejected from other cleaning equipment for fibre saving. such as pressure screen rejects or the lightweight rejects from centrifugal separators. 
The use of either perforated or slotted serene plates makes for the convenient adaptation of the vibrating screens to any screening requirement.
The high frequency of vibration of the screen basket provides rapid rejects removal and vibrational amplitude is greater than the maximum fibre length which precludes any plugging of the basket and gives a high screening efficiency. 
All the principle components of the vibrating screens are stainless steel with the exception of the eccentric drive shaft which is EN 8. The drive shaft is mounted on spherical roller bearings and enclosed in a stainless steel, fully sealed bearing cartridge which is easily removed from the screen body on site thus reducing maintenance downtime. 

Belt Presses

The belt press is used for water clarification or consistency thickening with a consistency range of O.5%-40%. 
The headbox and feed chute create a constant uniform flow over the entire width of the upper wire, which runs counter to the stock flow, Foils create a low pressure zone to pull the water from the stock, drying the mat on one side. Shoes positioned above the foils continually turn the stock to enable de-watering throughout the fibre mat. A hexagon bar vibrates the upper wire, agitating the stock, and increasing the de-watering effect of the foils. Plastic retaining strips run the whole length of the suction zone, ensuring the
stock remains on the upper wire. Once the upper and lower wires meet, the fibre mat is compressed by a section of offset rollers, squeezing water from the fibre mat. Thickened stock falls off the lower wire to continue through the system, with the removed water having been collected in stainless steel catch trays for recycling. 
Pneumatically operated stretch gears alter tension in the wires. To ensure that the wires run in the middle of the rollers, two guide units are installed. These operate by the displacement of a spade against the wire, adjusting the alignment of the guide roll, re-centering the wire.

Heavy Duty Presses

HEAVY DUTY PRESS
CONCEPT/DESIGN 
Mill Hill designs press sections to optimise the three basic functions of the paper machine wet press: 
(1)  To maximise the water removal from the wet web by mechanical means without jeopardising essential sheet properties such as bulk, opacity, smoothness, etc
(2)  To provide adequate support for the wet web in order to obtain full machine operating efficiency.
(3)  To efficiently remove the expressed water from the machine through effective savealls, felt cleaning and conditioning equipment. 
The design of the press section is controlled by the paper grade, the machine speed, width, space availability, and by the amount of water capable of being removed by pressing.
The press sections are carefully arranged to minimise time and production losses required for clothing and roll changes. The convenience and safety of the operator are paramount design considerations
Maximised water removal is achieved through carefully balancing specific nip pressures (PU), nip width, dwell time in the nip, felt weight, felt permeability and felt water load. Pelt conditioning equipment ahead of the working press nip is a highly critical design consideration that can materially influence the operation of the whole press section. 
Basic press types are available for specific applications-each adapted to the unique requirements of the individual mill or machine involved

Drum Thickeners

Drum thickeners can be used for fibre recovery from backwater systems or for increasing stock consistency with the inlet/outlet consistency range of O.5%-8%.
Stock uniformly flows over the lip of the weir into the vat. An overflow is located on the accept side of the drum, which keeps a steady flow pattern in the vat. The drum sits offset from the centre of the vat towards the accept side. This creates a compression zone, that de­waters the stock through the drum fabric, forming a fibrous mat. The mat remains attached to the drum hydraulically, as the water level inside the drum is less than that in the vat. As the drum rotates, the mat is lifted out of the vat and held via gravity, where it is also de­watered. A rubber covered couch roll transfers the fibre mat from the drum into the accepts chute.
 The drum thickener is of robust fabricated construction, with all wetted pats of stainless steel. A face cloth, which covers the perforated drum, can be bronze, stainless or plastic, dependant upon the application. A 1” thick rubber cover of varying hardness, dependent upon the application, covers the couch roll. Located on the couch roll is the doctor blade, consisting of a beveled plastic strip bolted to a fabricated apron and stainless steel clamp plate. Altering the pressure between the couch roll assembly and the drum is achieved pneumatically. The drum is driven via a helical/worm geared motor and reducer direct coupled to the cylinder journal.

Lo & Hi Consistency Cleaners

Low consistency cleaners are used for the tine cleaning of all fibre stock suspensions, usually in the constant part of the paper machine, by the removal of such impurities as sand, splinters, etc. Lightweight materials (polythene, foamed plastics. stickies. etc.) are eliminated when using the 'E’ type cleaner with its special head arrangement. The ‘E’ type cleaner is also used for the removal of entrained air. Dirt elimination is based. on centrifugal force, such impurities as have a greater mass than the fibres are flung towards the wall of the cleaner conical body and rotate downwards to be discharged, together with a small amount of stock at the small end of the cone. With the ‘E’ type cleaner light weight materials are discharged through a tube passing centrally through the inlet head. The highly efficient and economic cleaning effect of the low consistency cleaners is achieved with a differential pressure of approximately 22 mWG. To minimize fibre loss centrifugal cleaners are almost invariably used in multistage systems. 
All the components of the low consistency cleaners are of stainless steel, with the exception of the rejects cone which can be stainless steel, ceramic or high density plastic.

Low consistency cleaners are used for the tine cleaning of all fibre stock suspensions, usually in the constant part of the paper machine, by the removal of such impurities as sand, splinters, etc. Lightweight materials (polythene, foamed plastics. stickies. etc.) are eliminated when using the 'E’ type cleaner with its special head arrangement. The ‘E’ type cleaner is also used for the removal of entrained air. Dirt elimination is based. on centrifugal force, such impurities as have a greater mass than the fibres are flung towards the wall of the cleaner conical body and rotate downwards to be discharged, together with a small amount of stock at the small end of the cone. With the ‘E’ type cleaner light weight materials are discharged through a tube passing centrally through the inlet head. The highly efficient and economic cleaning effect of the low consistency cleaners is achieved with a differential pressure of approximately 22 mWG. To minimize fibre loss centrifugal cleaners are almost invariably used in multistage systems. 
All the components of the low consistency cleaners are of stainless steel, with the exception of the rejects cone which can be stainless steel, ceramic or high density plastic.

Deflakers

Deflakers open up the stock into individual fibres, which ensures uniform development and improves the technological properties of the paper sheet. Stock enters the deflaker through the front casing and outer stator disk, passing through the perforations of the tutor disk. and is uniformly distributed on either side of the rotor. As the stock moves outwards towards the periphery of the disks, it is forced into and out of the perforations in the rotor and stator disks, bringing the stock continually into contact with the edges of the perforations. This action together with the high turbulence within the unit and the internal fibre to fibre action causes any fibre bundles to open up. 
The body of the deflaker is of fabricated mild steel with all wetted parts stainless steel lined. The rotor and stator disks are of heat treated stainless steel. The EN 8 drive shaft is carried on spherical roller bearings. 
Disc refiners can be used to modify fibres from chemical and mechanical pulps, waste paper, and fibreboard stock, ahead of the paper machine. By selection of the most suitable refiner tackle and by optimising operating parameters. the refining effect on the fibres can be matched to customer requirements. Mill Hill Heavy Engineering refiners are fitted with rapid load relieving devices as standard, which centres the rotating element between the fixed elements in the event of stock flow failure, thereby protecting vulnerable and costly refiner fillings. Refiners are built to operate under the severest of conditions and are designed to reduce maintenance downtime to a minimum.

Trashex

The trashex is designed as a virtually clog less pump, but with the added benefit of a rotor designed to defibre the stock, thereby assisting the fibre recovery from any following equipment. The Trashex is suitable for operation with either batch or continuous pulpers. When operating with a batch pulper, the trashex is only run when as much stock as possible has been accepted through the rotor screen plate. Then operating with a continuous pulper, adjustable timers control the Trashex, the frequency of operation being determined by the degree of stock cleanliness. This removes a portion of the furnish for screening/cleaning, thereby continuously cleaning the pulper.
The Trashex consists of a fabricated mild steel body and strengthened stainless steel lined door. The stainless steel rotor is mounted on an EN8 driveshaft, carried on anti-friction bearings housed in a mild steel bearing cartridge.

Screw Compactors

Their robust construction, incorporating spherical roller thrust bearings for axial loading and spherical roller bearings for radial loading, ensures that the compactors withstand the most rigorous of operating conditions. 
These operating conditions have ranged from can crushing to sludge compaction although the primary design function has been as a means of reducing disposal costs of waste materials, for example the rejects from vibrating screens. When used for this type of duty payback times six months or less have proved to be easily achievable. 
Material enters the compactor via an inlet hopper and is conveyed along the tubular body by a constant pitch screw. At the far end of the body is a control flap which is held in position by pressure controlled air bellows. 
As the waste material is forced against the flap it is compressed and de-watered. Any water forced out
leaves the compactor by means of a series of perforations in the lower half of the body tube and is collected in a catch tray to be piped away for re­cycling. 
Compacted material is forced past the control flap and drops out of the end of the tube into a skip for disposal. 
The compactor drive is from a geared motor unit mounted directly onto the drive shaft which is carried on thrust and radial bearings which are fully sealed from the compactor body and further protected by a finger arrangement. 
The compactor screw is coupled to the drive shaft and is easily removable from the longitudinally split body for maintenance purposes.

Rotary Junker

The rotary Junker is designed to perform either of two functions.
 1.  Using a screen plate and rotor arrangement to defibre and screen stock from the pulper. Cleaned stock passes through the screen plate into the accepts chamber, where it is pumped onto the next piece of equipment 
   2.  Using a toothed rotor and wear ring arrangement to screen out large impurities, both heavy and light, from stock abstracted directly from the pulper tub. Accepted stock passes back to the pulper via the pump vanes on the rear of the rotor
 For function 1 the unit can be sized for either continuous or batch operation. For function 2 operation time is determined by furnish cleanliness.
 In all instances the rotary junker is periodically cleaned of collected impurities. Washing the impurities collects any entrained fibres and passes them into the accepts line. Air is introduced into the rotary junker to minimise the amount of water retained in the rotary junker body prior to the dump valve being opened to discharge the collected contraries.
 The wash and dump cycles are automatically controlled by pre-set sequence controls.
 All wetted parts are stainless steel. The rotor is carried on an EN 8 driveshaft supported by spherical roller bearings mounted in a fabricated mild steel bearing cartridge. This is driven via ‘V’-belts from an overhead mounted motor carried on a mounting/jacking plate.
 A quick release cartridge comprises of the drive, motor and extraction chamber. These are mounted on wheels for easy access for maintenance and so rotor clearance can be set outside the machine.

Conveyors

Conveyors are generally of an overlapping steel slat apron design, although this is subject to customer duty requirements.  The slats are bolted to link attachments, carried on 60,000 lbf breaking strain, solid bearing pin chains. The conveyor chain framing is extended upwards to carry slat aprons, preventing loose material spillage.  
The conveyor tail and framework incorporates heavy duty take-up units for chain tensioning.  The driveshaft is mounted in spherical roller bearings and is driven via a helical/bevel gearbox and Duplex chains.  On wider slat units, central supports carrying high density wear strips are provided.

 
 
 
Springbank Mill
Albert Street,
Blackburn, Lancashire.
BB2 4BL