Brentwood MPS and SM plants are an all in one solution for the processing of greenwaste, MSW, and builder’s waste. The unique feature of these plants is the combined use of two feeding mechanisms and, in the case of the Shredder Mill, the use of a bypassable refiner after the dual shaft shredder.

A horizontal conveyor and driven overhead roller ensures positive feed to the shredder. Also included is a discharge conveyor to stockpile the shredded material. Being PLC controlled this range of machinery requires minimal operator involvement.

The following information applies to Models MPS/SM-50HD through to MPS/SM-150W

The basic plant consists of:

1. Infeed Hopper – with steel apron feeder floor
2. Shredder –  dual shaft shredder from 37 to 110 kW
3. Refiner (SM plants only)  – can be bypassed to shred tyres etc
4. Discharge Conveyor – Cleated belt
5. Feed Roller – Driven roller to condition infeed material prior to shredding
6. Control Cabinet  – PLC based control

Also available are a number of options to further enhance the operation of your plant such as Magnetic Separation and Screening.  Multipurpose Shredding Plants and Shreddermills are available as Mobile Plants supplied as trailer or skid mounted.

In all cases, the infeed hopper fixes to the shredder and is fabricated from AS250 steel plate. The loading side is lower than the rear side to assist in preventing product falling behind the machine, whilst keeping the loading height to a safe minimum. The end of the hopper is normally in the form of a door and has micro-switch protection so that if the door is opened whilst the machine is operating, the whole plant will shut down. The door is provided to allow unshreddables to be ejected by reversing the feeder.

The floor of these is a moving floor or apron feeder and is manufactured using close-fitting plates approximately 150mm wide connected to long link chain sections. The close-fitting plates minimise the amount of material falling through the feeder onto the floor or ground underneath and therefore not requiring constant cleaning. Machinery using open type feeders do have this problem. At intervals, cleats are welded to the plates to give additional traction to the feed. The feeder is driven by a motor gearbox combination driving through a chain drive to the head pulley sprocket.

Hardened steel wear blocks on the underside of the plates are in contact with alloy steel wear strips to give support to the plates. This conveyor is based on the This conveyor is based on the Brentwood Apron Feeder conveying system.

All Brentwood Shredders use a twin counter-rotating shaft design principal. Shaft rotation is approximately 25 rpm. The product to be shredded and the volume of production required are key factors relating to Shredder selection. The actual shape, number of hooks, thickness and configuration of cutters are all factors to be considered for a particular application.

Interactive consultancy with the Brentwood engineering team ensures correct application of the machinery.

The production rate and size of feedstock decides the power requirement. Brentwood Shredders are unique in design providing overload “BACK OFF”. If during the normal operation of your plant the shredder encounters foreign material which overloads the shredder motor, the shredder will stop, reverse, stop, then start forward again. The facility is provided to preset the number of reversals allowable prior to shut down and/or alarm, or if desired no limit can be placed on reversals. This system helps to protect the shredder from damage. In many instances, the shredder will, after a couple of reversals, shred the material then carry on with the rest.

If the shredder shuts down, the feeder can be reversed and foreign material can be dumped out the back of the feeder. It should also be noted that when the shredder reverses, the feeder will stop till the shredder current has dropped to a normal level, then starts forward again.

Cutters used in these machines are manufactured from case-hardened alloy steel. Day to day maintenance is extremely low compared to high-speed hammermills. The ultimate life of cutters is dependent upon the product being handled. The time between major overhauls usually exceeds 4000 hours but is dependant on the material being processed and other local factors. Simple maintenance of cutters is a matter of hardfacing and hand grinding in the machine. It is not uncommon to reach periods of 6 – 12 months before this is necessary.

In conjunction with the moving floor the feed roller provides a positive feed to the shredder. This is a device placed above the moving floor, pivoted to obtain its own height setting automatically and positioned just before the shredder. On some products, this is necessary to maintain continuity of product to the shredder. The feed roller is driven by an electric motor/gearbox combination attached directly to the shaft of the roller. Overload protection is provided.

This is usually a cleated conveyor belt emerging from under the Shredder, and reaching an elevation of approximately 2.7m. If the optional refiner is fitted then the discharge conveyor is located on the outfeed of the refiner. The height of the outfeed is variable from 1.5m to 2.7m by fitting the conveyor on a horizontal pivot.

Refiner

Adding the Refiner to an MPS plant creates a Shreddermill Plant

This is a specifically designed hammermill placed after the shredder to further refine the product to a required size. This may be necessary for composting requirements. It is used when processing vegetation or wood waste which has little contamination.

Size variation is obtained by the use of various screens.

Shreddermill plants the mill can be bypassed. By operating a diversion gate between the shredder and the mill, the product can be deflected from the shredder direct to the outfeed belt. This feature is used when processing tyres, white goods or excessively contaminated product.

SM and MPS Shredding Plants

MPS Plant