High Pressure Pumping Simplified For Mining
Pumps are used widely in industry to provide cooling and lubrication services, to transfer fluids for processing, and to provide the motive force in hydraulic systems. In fact, most manufacturing plants, commercial buildings, and municipalities rely on pumping systems for their daily operation.
Plants generally rely on a multitude of pumps to move raw materials, intermediates and products, and to supply, recycle and remove essential utilities such as water, heat-transfer fluids and the like. Proper selection and operation of pumps plays a key role in keeping a process running smoothly.
In South Africa there are many uses for high pressure pumps, whether it is in deep mining in the gold and platinum mines, in coal mining, or open cast iron ore mines. Normal cleaning of machinery and vehicles for maintenance or repair are the most common general purpose applications.
There are many special purpose versions that Hawk Pumps have been asked to design, in its almost 40 years of existence in South Africa, it is not surprising that a large proportion of them are for specially designed machines, a lot of which are manufactured for customers in Eritrea, Uganda, Burkina Faso, Zimbabwe Mozambique, Zambia, Namibia, Angola, DRC to name a few.
Pump reliability is important—often critically so. In cooling systems, pump failure can result in equipment overheating and catastrophic damage. In lubrication systems, inadequate pump performance can destroy equipment. In many mining, petrochemical and power plants, pump downtime can cause a substantial loss in productivity.
In addition to an extensive range of sizes, pumps also come in several different types. They are classified by the way they add energy to a fluid: positive displacement pumps squeeze the fluid directly; centrifugal pumps (also called “rotodynamic pumps”) speed up the fluid and convert this kinetic energy to pressure. Within these classifications are many different subcategories. Positive displacement pumps include piston, screw, sliding vane, and rotary lobe types; centrifugal pumps include axial (propeller), mixed-flow, and radial types. Many factors go into determining which type of pump is suitable for an application.
Continuous Coal Mining Machines
These machines require pumps for lubricating the cutters in order to extend their life and to help with dust suppression. These pumps have been widely accepted because of the relatively low price as well as their reliability, as they are hydraulically powered, needing very little space and fitted to a base which can easily be removed and replaced for repair.
Iron Ore Open Cast Mines
Large volume, high pressure pumps mounted on huge tanker vehicles can clean the electrically powered ore trucks for repair on site. The pumps are powered by diesel engines and have large volumes to allow the water jets to reach inaccessible parts of the trucks.
Deep Shaft Mines
These mines have a multitude of applications for high pressure pumps.
Trailer mounted electrically or diesel engine driven pumps are useful for cleaning slurry pipes when fitted with long hoses and special pipe cleaning nozzles. The nozzles, with back facing jets pull the hose through the pipe, removing the scale and pushing it backwards.
Boiler and heat exchanger tubes have to be routinely de-scaled. Pumps up to or over 500 bar, power spinner nozzles which effectively break up and remove the scale as the hose is pushed through the tube.
After the ore face has been blasted there is a period when personnel have to be away because of the dust and toxic gasses. High pressure misting nozzles help to clear the atmosphere, allowing ore removal to continue quicker.
The Hawk Stope Washer (“Water Jetter”) has been designed to move rocks up to 35Kg to the gulleys with water impact instead of mechanical means. The most popular version delivers 150 l/min at 100 bar. The pump is fitted directly to a 6-pole 30Kw motor in a special monocoque skid chassis which can easily be winched into position over rough floors.
Features which make it particularly good are:
- It is fitted with a custom made, built-in strainer to ensure clean water reaching the pump.
- There is an under-pressure switch safeguarding against starvation of the pump and an overpressure switch ensures that if the unloading pressure regulator fails, the machine switches off.
- The covers simply slide together and are locked with over-centre latched. No spanners required and no lost nuts and bolts, ensuring that the lids are replaced while the pump is operational.
- The operator merely has to close the gun for the machine to switch off. This avoids him having to crawl back up to 80m to manually shut it down. The machine has a low risk rating.
Another very important special design is where water is used to drive a water powered drill to replace the pneumatic ones. The results are that a 1,2m hole taking 8 to 10 minutes can now be drilled in 1 to 1.5 minutes. The effect on the operator is very much lower. Once again the machine (the powerpack) is contained in a monocoque casing with easy access covers for onsite repair or maintenance. This machine was originally designed in conjunction with HPS systems. Several different sized machines are available depending on the number of drills to operate simultaneously. Pumps mounted in the lifts in the shafts are used to remove dust from the steel structure.
A High pressure pump unit has been designed to connect to rows of Hawk rotating nozzles to agitate the mud and increases the efficiency of the sorting of the stones.
Melanie Makowem, Managing Director Hawk Pumps, enlightens that they have specialized in the manufacture and distribution of high pressure cleaning equipment, road marking equipment, safety shower equipment, high pressure pumps and airless spray painting solutions for over 40 years.
While high pressure pumping equipment is still the main core of operations, industrial spraying nozzles are a big part of it, as are airless spray painting machines, road markers, safety showers and eyewash units. Thus all of the products fall into the general category of “high pressure pumping and spraying”
Precision engineering and the use of high quality materials have enabled Hawk Pumps in South Africa to give a comprehensive guarantee to cover their products. A full one year’s warranty covers the workmanship and materials against defects (excluding wear and tear items) on all manufactured units.
Hawk Pumps have an enviable reputation for being able to custom design solutions for local problems. All equipment is manufactured locally at the Durban factory where quality and practicality are always considered. The resulting solutions are designed to be robust enough for the tough African market.
Our cleaning and spraying products, Melanie clarifies, by nature, are suited to fighting COVID-19. With a little imagination and a lot of gumption, we have adapted our core in-stock product range to come up with innovative solutions, while other companies were struggling to import products during lock-down.