Evolution of a throughbred
Invented in the year 1923, the Symons 7 feet crusher revolutionised crushing in the mining sector. In the times when super heavy duty series were developed, the Symons crusher was developed to be a true workhorse of the mining sector.
In between 1975-1985, Metso (erstwhile Nordberg) underwent intense R&D on different operational variables of high speed cone machines and following results concluded due to that research over the spectrum of operating parameters tests:
A) Throw was proportional to crusher capacity.
B) Speed was inversely proportional to crusher capacity but proportional to particle shape.
C) Throw and speed were inversely proportional to unit stress.
A new product
Eventually the results lead to HP series thereby developing HP800 crushers at par in features with Symons 7 feet cone crusher.
• HP800 series operates with faster countershaft speed than older conventional cone crusher. So with increase in speed higher reduction was achieved and particle shape also improved. To counter its decrease in throughput capacity attributed to high speed, the throw was increased which ultimately increased in crusher throughput.
• HP800 cone crusher has improved head action due to high fulcrum pivot point, which helps crushers to start crushing efficiently from top of crushing cavity.
• HP800 cone crusher has a high power rating as these crushers have high reduction and capacity which ultimately requires increase in power rating of crusher.
• With combination of increased speed and throw of cone , HP800 crushers create a multi layer of interparticle crushing action which resulted in :
i) Material size reduction by compressing a layer of stones between two hard surfaces.
ii) Combines compression type crushing with attrition (grinding).
iii) Inflicts crushing forces from multiple angles onto the particles, increasing frequency of crack propagation.
iv) Produces the higher quantity of possible yield, the most consistent product gradation and the very best particle shape.
• In HP800 Cones, as a result of increased speed, throw and cavity design, approximately 80% material generally comes out of bottom of new Cone crusher passing CSS.
• HP800 Cones use hydraulic motors to adjust crusher setting. These crushers are capable of quick adjustment which permits fine tuning of setting throughout shift and ultimately allowing to produce higher percentage of target product. Secondly their productivity maximized due to less work interruption in the working shift.
• HP800 Cone crushers with its features enabled to visualize and develop an automation, with periodicity controlled setting to maintain consistency in high production, with other various benefits which includes: metal to metal calibration eliminating the need for slugging and in doing so increases precision in setting; liner wear prediction for better maintenance planning; and automatic unit control of cone crusher feed rate and setting.
• Online availability of HP800 Cone machines became higher as tramp release cylinders allow releasing the bowl liner in order to pass tramp material. It also allowed clearing the crusher cavity by lifting the bowl liner up and away from mantle. The hydraulic hold down cylinders and reverse hydraulic clearing cylinders also greatly increased safety by eliminating human exposure when clearing a crusher stalled by tramp material and eliminating maintenance and replacement of springs under high pressure.
• Maintenance and operation improvements include:
o Quicker and easier liner changes: gear driven bowl assembly can be removed quickly; head is separate from main shaft, making removal for mantle changes easier. Bowl liner is engaged by easy wedge system.
o Compared to 7' Symons, HP800's overall height and weight is less, and the components to be handled for maintenance are lighter and less bulky.
o Mainframe and seating surface can be inspected by raising clearing cylinders without any disassembling of the crusher.
o Clearing stroke of HP800 significantly higher than 7' Symons, allows cavity clearing with a push of the button (no “dig out” of the cavity).
• HP800 is designed to fit onto a 7 feet Symons cone crusher foundation that translates into higher productivity with substantial saving in plant modifications.
HP800 Lubrication system
Clean simple design where pump is directly coupled with motor. This model has been built around a design that reduces noise. Optional water cooling arrangement is available. System installed on drip pan to contain oil spillage. It can be easily interfaced with plant PLC. It comes complete with pressure, temperature and proximity switches. Armed with an improved filtration system, the optional design has redundant pump and filtration system to increase availability.
HP800 Hydraulic system
This has a compact design for installation near crusher and also allows local control near crusher. Consisting of Hydraulic pump, accumulator and solenoid valve block its simple design makes it easy to access its components. Pressure can be measured through sensors and valve positions can be controlled through actuators. All sensors, actuator, wired to terminal block mounted on unit. PLC has been installed and programmed to operate unit that also allows easy connection to plant control system.
HP800 -TC 1000 Automation
Automation allows the plant to operate consistently at optimum capacity maximizing product shape and product quantity, it also lowers operating cost, adds protection of the equipment, increases ability to plan for maintenance, and improves profitability.
That’s why HP800 is reckoned as high performance cone crushers attributing to this reason over 150 HP800 crushers have already been installed since 1990 with approximately 85% of these going into mining application.