Cement handling and storage

Mobile equipment from Telestack: flexibility and efficiency for cement industry

Telestack offer a range of mobile bulk material handling solutions. This article details three case studies, which illustrate three different applications. They show the flexibility that Telestack’s technology provides to the cement industry.

CASE STUDY 1 

Telestack’s customer in Europe operates a limestone quarry for its cement plant operation. It handles a range of materials for construction and cement manufacturing such as lime, cement, plasters, mortar, crushed sand, aggregate and various environmental products within its plant. It is critical that these materials are handled in the correct manner.

To reduce costs and improve this process, the customer installed the Telestack radial telescopic stacker which is used to stockpile the raw material for the plant that was to be loaded into the furnace for the cement making process. During this process within the furnace, the material can only be loaded if it is within certain specifications; this is to ensure that only the ‘in-specification’ material is fed into the system to ensure the correct product ratio. For the customer to achieve this ‘in-specification’ material,Telestack installed the radial telescopic stacker to automatically stockpile the material in windrows. The method of stockpiling is scientifically proven to reduce/eliminate the segregation, degradation, contamination and compaction of the material.

The radial telescopic stacker automatically stockpiles the material and radials left/right via the electric hydraulic driven wheels, raise/lowers and telescopes in/out to allow for a  windrow type stockpile to ensure the ‘in-specification’ material is maintained throughout to feed the furnace. The all-electric driven unit stockpiles up to 96,600 tonnes of material at 270° (based on 1.6t/m3) in one area for large stacking capabilities. The unit is fully integrated into the current electrical communication system within the plant so it can be monitored and controlled from one central location. The inclusion of full length galvanized dust covers ensure there are minimal dust emissions on site. Also, the dual access walkways the length of the outer conveyor allow for easy maintenance and safety for the operator. At a full length of 42 metres (140ft) length, the TS 542 radial telescopic stacker can discharge at heights up to 13.05 metres (43ft) at 500tph (tonnes per hour) for maximum capacity in the small areas within the site.

By utilizing Telestack’s technology, the customer has reduced his operating costs significantly. The elimination of the use of wheel loaders for stockpiling the material has meant a saving of 3,000 hours per year of operation of the wheel loader, which if we consider the fuel consumption, labour and maintenance (tyres and so forth) of a typical medium-sized wheel loader, these are significant savings. In terms of fuel alone, the customer has saved 40,000– 50,000 litres of diesel per year by using the Telestack radial telescopic stacker in place of the wheel loaders that were previously in operation. Also, from an environmental point of view, the carbon emissions have been significantly reduced on site, the noise level is reduced and the dust generation is significantly less.

Telestack can also help improve site safety as the elimination of wheel loaders reduces site traffic movements and the potential for accidents.

CASE STUDY 2

Vessels and unloads the vessel using mobile harbour cranes into conical hoppers. Road trucks receive the material from the conical hoppers and bring the cargo to the covered storage area. The trucks then reverse onto ramps which are hydraulically foldable for transport and they will then tip the material into the Telestack mobile truck unloader for the stacking of the material. The material will be regulated in the feeder by means of a leveling blade which can be manually adjusted. The material is then transferred via a chute incline radial conveyor boom. The boom has the ability to slew ±45°, creating a radial stockpile. The radial boom slews on slew bearing and is driven by a hydraulic motor with limit switches, limiting the slew range to a maximum 45° angle of centre line in left/right direction. The incline boom can be positioned at a angle of inclination from 8° up to 23°.

An additional feature of an ultrasonic height sensor allows for a minimum drop height of clinker which reduces dust emissions and degradation of the material. The unit can stockpile to a height of 9 metres which gives a conical capacity of 1,680 tonnes at 1.4t/m3 and a radial stockpile capacity at 90° of 6,125 tonnes.

The truck unloading/stockpiling machine is fully self contained with a CAT 4.4 litre engine generating 96Kw of power. The mobile truck unloader is track mounted and has optional rubber pads therefore not marking the concrete within the storage area.

The client commented that the TU521R will significantly reduce his operating costs for stacking of the clinker in the storage area. Prior to this contract, a 30-tonne excavator was used which would only attain a heap height of 6 metres. The client also will increase his storage capacity with the same footprint. He also expects less dust to be generated when stacking, a better quality product and a safer environment for his employees.

CASE STUDY 3

Telestack has recently commissioned and installed a mobile reclaim hopper into a sand and gravel operation in Europe. The client replaced a previous system which could only be fed with a 50-tonne excavator and consequently the diesel consumption for the excavator was excessive. The client had a very specific design brief for the new mobile reclaim feeder and some of the technical features are listed below with regards to the unique design to meet the client’s particular requirements.

The client chose a CAT 980 wheel loader to perform the reclaim operations from the mineface to the mobile reclaim feeder. Due to the reclaim hopper being track mounted, it can be easily manoeuvred along the uneven mine surface to a suitable

position from where the wheel loader will feed it. This distance can vary between 20–50 metres. After 50 metres, load and carry distance has been reached the client moves the ground conveyor closer to the mineface and repeats the process.

The wheel loader picks up the run-of-mine material which ranges from fine sand to 350mm gravel boulders. The wheel loader then carries the material to the hopper which is fitted with 1,500mm aperture tipping grid. The grid is a heavy duty construction and the grid bars are made up of coffin shaped bofor bar. The grid size is remote control operated from the driver’s cab of the wheel loader.

The grid can be tipped to an angle of 80° which enables the effective removal of boulders which normally would become entrapped in the grid. The grid is reversible which enables it to be quickly changed to tip either side of the hopper. The material greater than 150mm is rejected and material under than 150mm passes through the grid and into the hopper which is lined with 10mm Abro 400 liners.

The hopper has a capacity of 18m3 and incorporates a drag out feed out conveyor. This feeder is speed controlled by means of a variable-speed drive and in conjunction with a variable height gate means that the client can finely set the machine output. The feed conveyor of the hopper is fully skirted up to the discharge point where it passes onto the incline conveyor. The incline conveyor has the ability to slew ±90°. The incline boom also incorporates an anti roll back system to prevent the larger boulders from rolling back in event of material feed stopping.

The complete system is powered by a 165kVA CAT enclosed generator set or can be powered by mains electricity to further reduce operating costs. From the mobile reclaim conveyor the material is then transferred to a ground conveyor which feeds the material onto a primary surge stockpile. The stockpile is automatically reclaimed and gives a buffer of three days processing to the crushing and screening plant.

The client has realized the benefits both in terms of reduced operating costs for reclaiming and also increased manoeuvrability and quicker set-up times.

TELESTACK

Telestack offers a range of mobile bulk material handling solutions which are in operation across the globe handling materials such as coal, iron ore, aggregates, fertilizer, grain etc in mines, ports, quarries, power plants, steel mills and cement kilns.

It is estimated that 5–6% of total man- made greenhouse gases are the result of cement production. Some of these emissions from conventional cement production are caused by using fossil fuels to heat up limestone to the high 1,500°C required by the process. It is therefore unsurprising that alternative fuelling methods are now being thoroughly investigated. The use of alternative fuels in European cement kilns is now estimated to be equivalent to 2.5 million tonnes of coal per year.

The use of alternative fuels is considered to represent the Best Available Techniques (BAT) for all cement manufacturers. Many UK cement producers have signed a climate change levy agreement with the UK government. The agreement sets a target of both kiln fuel and electricity, which will result in a substantial reduction in carbon dioxide emissions.

Alternative fuels used in cement manufacturing have differing characteristics such as SRM (secondary raw materials), RDF (refuse-derived fuel), SRF (solid recovered fuel) and PSP (pelletized/processed sewage pellets) when compared to the more conventional fuels. Switching from conventional fuels to alternative fuels presents several challenges that must be addressed in order to achieve successful application. Poor heat distribution, unstable pre-calciner operation, blockages in the pre- heater cyclones, build-ups in the kiln riser ducts, higher SO2, NOx and CO2 emissions, dusty kilns and excessive wear in pipe work, valves, burners, chutes and cyclones are some of the major challenges.

The same problems arise in the increasing number of industries that are replacing fossil fuels with renewable materials or supplementing fuel streams with mixed waste and recyclate in order to achieve carbon offset. However, managing biomass and mixed media can take its toll on processing equipment unless it has been designed or adapted for handling products with varying characteristics that create excessive abrasion and corrosion.

Kingfisher Industrial is a world-recognized expert in the protection of plant and equipment for handling aggressive materials, such as mixed media fuels for cement plants, power generation, chemical processing and incineration.

By implementing best engineering practice, Kingfisher says that key plant and equipment can operate on a continual basis and lead to increased efficiencies and profitability. The company has considerable expertise in combating wear and corrosion within cement and other heavy industrial plants and has frequently extended the service life of key processing equipment by utilizing its range of protection systems.

Kingfisher works with a number of preferred materials suppliers to offer an unbiased approach to solving the problems experienced when handling bulk solid materials and allow it to offer the best solution or solutions for any given situation.

Despite manufacturers’ many claims to offer the ultimate material in the ‘fight against wear’, success levels can vary enormously, so there is a need to analyse each individual set of circumstances. Sometimes the wear-resistant properties of one material type may be in excess of requirements and conversely, those same properties may under-perform in a different application, putting the material’s suitability in either case under question. Careful assessment is a key requirement for success.

Technically speaking, three familiar material groups are most common for wear protection duties: ceramic, metallic and polymer.

Ceramics are available in their long-established cast form and as state-of-the-art pressed products and are used in many, many situations: they range from high alumina, fused cast basalt, silicon carbide to fused corundum.

Metallic solutions are usually based on hardened versions of common metals and are suitable for a wide range of applications. They have been in use for many years and are much favoured by many users. Specialist metal alternatives are also available and can provide the optimum outcome to unusual situations, such as high chrome, ni-hard, manganese castings and chrome carbide overlay plate. Polymers like rubber often work in a counter-intuitive way, having the ability to absorb the shock of impact and dispel the damaging forces. Other polymers such as polyethylene, with its very low coefficient of friction, encourage the material to glide over it as opposed to scouring the surface thus, reducing the effects of friction or sliding induced abrasion. Polymers tend to be lightweight, flexible and relatively easy to apply.

The use of polymers to protect equipment where extreme impact prior to crushing is evident benefit from being lined with hard rubber liners and likewise the difficulties associated with the storage of coal and cement are eliminated due to the low coefficient of friction that polyethylene liners offer in assisting discharge. In all of these cases and in many more, the cement industry can achieve significant benefits when employing wear- resistant linings and wear-protection systems. New or existing equipment can be retrofitted with a protection system to add to its current asset value.

Kingfisher has wide expertise with all three material groups and carefully tailors solutions to each specific situation. Before making recommendations, Kingfisher undertakes a full in-depth analysis of a plant’s operational criteria and identifies a system that is fit-for-purpose to meet the many requirements of the end user. Criteria that are reviewed in the decision making process include the type of material being conveyed, size and shape, volume and velocity, operating temperature and of course the budget constraints versus the operating life cycle required.

Kingfisher has installed its wear-resistant lining solutions within a number of plants that use the different types of alternative fuels. Referring to a project carried out at a cement plant situated in Derbyshire, the manufacturing plant has been working with the SRF since 2009. During the installation of the SRF system, Kingfisher was approached by a process engineering company to supply pipes lined with K-BAS Cast Basalt wear- resistant lining systems. After a couple of months of operation, the plant was advised to upgrade its conveying bends to K-ALOX ceramic wear systems instead. “Due to the erosive nature of the material, the K-BAS lining system did not meet the life expectancy of the system,” commented MD John Connolly,“as part of our after-sales service our engineers identified the problem and advised the customer to upgrade the lining system to an alternative material type’’ Adding to the process Kingfisher has engineered bends with a removable wear back that is fitted with its very own Abralarm wear-detection system. The system comprises a low voltage electrical indicator that is integrated between the lining system and steel casing; when the lining system is breached, it will sever the induction loop and send a signal through to the SCADA/PLC system located in the customers central room which enables the operation team to plan for replacements.

Kingfisher was also approached by the plant engineers to provide a suitable lining option for a silo used within the SRF process, the problems encountered by the plant included 50–80mm bed of excessive material which was recovered at the bottom of the silo after every shutdown. Usually the silo would be reasonably full, hence the lining solution provided must be able to endure high impact without causing any issues. During the site visit carried out by Kingfisher’s sales manager, he commented “the largest piece of material entering the silo was measured at 150×20×3mm thick. As material degrades in the silo, the moisture increases and the inside of the structure becomes saturated which in turn creates a dew point and excessive corrosion becomes a major problem if left untreated.

The solution suggested was Kingfisher’s polymer-based epoxy resin spray application. The characteristics offer a tough, impermeable barrier suitable for steel and concrete surfaces. Providing outstanding resistance to most chemical agents, particularly strong acids (including 98% sulphuric acid) alkaline, and many solvents. The low odour system forms a very hard and excellent gloss finish being evident on the surface of the plant and equipment.

The materials that make up typical mixed media and biomass fuels can create many problems due to the size, shape, density and tonnages that are handled. This is demonstrated by another international manufacturer within the cement industry, which has

used alternative fuels since 1992. It has done so by successfully implementing the use, of recycled tyres, meat and bone meal (MBM) and SRF. Kingfisher has supplied pipe work for the existing pilot plant, the pipe work supplied was lined with the K-BAS cast basalt lining systems.

Kingfisher has also supplied similar wear-resistant pipe work systems used at one of largest sludge drying centres in Europe. The plant processes sludge from hundreds of wastewater treatment plants into processed sludge pellets (PSP).

A Kingfisher solution will allow for this and will also optimize plant layout for clear flow lines without bottlenecks or other points of weakness. Applications such as the installation of low friction linings systems within the fuel reception hoppers can also eliminate the need for mechanical aids or personnel having to gain access in order to clear blockages. A Kingfisher-built or adapted system will generally need far less maintenance, as the protective systems reduce the need to continually undertake repair work.

Plant and equipment that can achieve continual operation when handling aggressive bulk solids in the harsh environmental conditions of cement production is of the utmost importance if efficient, lean production is to be achieved. Correct application of protection systems within process critical plant and equipment can deliver substantial savings in downtime and maintenance costs when engineered correctly, however investment in the wrong system being used in the wrong application can lead to increased costs all round!

ABOUT KINGFISHER INDUSTRIAL

Cleveland Cascades Ltd, renowned for its global supply of bulk material loading chutes for shiploaders and silo loaders, is seeing increased demand for its vehicle loading solutions, in particular in the cement industry.

The company has designed and supplied over 500 loading chutes since 1992, from shiploaders for alumina in Australia to silo loaders for coal in Israel. These systems use the company’s unique Cascade loading system, whereby the loaded material cascades vertically through an arrangement of oppositely inclined cones the length of the chute. The material is loaded at a low velocity, yet high volume, and this means problematic materials can be transferred with minimized dust emissions and also minimized degradation and segregation of product.

The vehicle loading solutions use the same Cascade technology, but whereas quayside shiploaders can be over 30 metres in length, the vehicle chutes need to be much shorter and to accommodate more frequent loading patterns and more intricate logistics of tanker and open vehicle loading.

The vehicle loading systems are more lightweight in comparison to shiploaders, but are designed with the similar operational functionality of the larger chutes. Material detection probes housed in the carrier of the systems allow for automatic raising on detection of material,

which facilitates continuous material loading. Limit switches in the hoist system can be set to allow travel limits which enable the optimum loading levels.

With a growing market presence in recent years, E-Crane has quickly become a major name in balance cranes around the world. The E-Crane has proven to be successful in the cement industry, with multiple sales and successes throughout Europe, North America, and especially Asia. Last month, we discussed the significant success of E-Crane in the Asian market. This month, we will be focusing on a more specific part of that market: the cement industry. E-Crane has proven time and time again that it can offer tailor-made solutions for that industry.

As discussed last month, the region in which E-Crane Worldwide has proven to be very successful is Bangladesh. In 2011 and 2012, E-Crane completed the installation of nine cranes for the cement industry in Bangladesh. Many customers did not order just one crane to operate at their facility, but two or even more. This is no surprise since the E-Crane is an ideal solution for handling not only cement, but also scrap and other bulk materials.

Among the companies which ordered an E-Crane during that period are the Bashundhara Group and Premier Cement Mills Limited (PCML). Two 1000 Series/Model 7264B E-Cranes were commissioned for the Bashundhara Group. Both cranes have a maximum outreach of 26.4 metres (86ft) and handle material for a grinding mill with a total capacity of 3,500 tonnes/day. Premier Cement Mills Limited purchased two 700 Series/Model 4264 PD-E E-Cranes with a 26 metre (86ft) outreach and 5.5 metric tonnes (6.0 US ton) duty cycle capacity.

Also, in July of 2012, Madina Cement installed a brand new 700 series E-Crane to handle cement for a grinding mill with a total capacity of 4,200 tonnes/day and a conveyor capacity of 500tph (tonnes per hour).

After making a mark as a supplier of a wide range of plant and machinery to Indian aluminium, steel and power sectors, China’s target is now the cement industry in the country, which traditionally is dependent on suppliers from the West for technology and plant building. Critical spares will also come from the West. Chinese arrival in cement machinery sector in India is heralded by Hong Kong-based Sinoma International Engineering, a subsidiary of Chinese government owned National Materials Group. Sinoma, which so far had a marginal presence in India by way of some ‘co-operation’ arrangements with French cement group Lafarge steadily adding muscles to its Indian business, recently acquired a majority holding of 68% in LNV Technology, a Tamil Nadu- based cement equipment manufacturer. LNV now becomes a joint venture between Sinoma in the driver’s seat and the original two promoters owning 16% each. Sinoma is the near monopoly supplier of cement machinery in China. It has over 40% share of the global cement machinery market, excluding China. Naturally, its arrival here in cement machinery manufacturing through a JV is widely welcomed for the competition it is going to create among machinery suppliers.

Sinoma is in the process of making LNV Technology a lot more than just a manufacturing platform. The JV will be enriched by regular flow of Sinoma R&D results, design, installation of machinery and equipment and after-sales service. The objective is to motivate clients to place repeat orders. No doubt, the acceptability of the Chinese group in the eyes of Indian cement manufacturers will rise by several notches with it taking management, production and customer service control of the JV. What now needs to be seen if LNV Technology will emerge as the leading supplier of cement machinery in India in the next five years, as is claimed by Sinoma.