Coal handling and storage systems

Shiny dome, clean coal — thanks to Geometrica

This article describes the collaboration that produced a circular coal-storage dome for Indonesia’s largest fertilizer producer, PT Pupuk Kalimantan Timur (Pupuk-Kaltim), write Francisco Castaño of Geometrica, Inc. and Ahmad Mardiani of PT Pupuk Kalimantan Timur. Pupuk-Kaltim has won numerous awards for its green practices and outstanding engineering. Pupuk-Kaltim selected Geometrica, Inc. based on its ability to meet some very specific logistical and environmental needs.

One possible problem, of course, could be environmental impact. Addressing that, Pupuk-Kaltim chose to use only clean- coal technologies, including a circulating fluidized-bed boiler, a Geometrica coal-storage dome and a continuous barge unloader. These technologies had earned recognition for their successful use at the JEA Northside power plant in Jacksonville, Florida, and help keep the environment around the facility pristine.

SPECIFICATIONS VIA THE INTERNET

After initial research on dome storage for coal, Mr. Supriono, a mechanical engineer with Pupuk-Kaltim, made the initial contact with Geometrica in 2009. The dome was to be supported by a 10-metre-high, reinforced-concrete, perimeter-ring wall and

would cover 40,000 tonnes of coal, plus a coal stacker and a portal reclaimer. Within a few days, Cecilio Zalba, Geometrica’s sales manager, emailed Supriono a proposal with preliminary drawings and a guide specification for an 80m-diameter, circular, galvanized-steel dome with aluminium cladding.

With that, plus input from possible alternate suppliers, Pupuk- Kaltim wrote a functional specification for the dome. The specification allowed the consideration of different dome- construction technologies, including concrete, aluminium and steel. The dome not only had to resist the specified environmental loads, withstand corrosive attack from the humid Kalimantan environment and help control explosion hazards, but also use technology that permitted fast construction by local crews and without special equipment.

SUPPLIER SELECTION

After carefully evaluating the various technologies and bids, the project builder, PT Inti Karya Persada Technics (IKPT), selected 

Geometrica as the dome supplier. “The contractor also received bids from manufacturers of concrete domes and aluminium domes,” said Zalba. “But the Geometrica solution offered more than 25% savings.” IKPT and Pupuk-Kaltim chose Geometrica, which set to work on construction drawings.

“This project was very similar to domed bulk-storage facilities we have built worldwide,” said Jorge Parada, Geometrica’s site consultant. “Our galvanized-steel dome technology has proved itself in many environments and applications. This one, along the coast of Indonesia in a tropical rainforest, is another great example.”

The galvanized-steel dome structure is clad with aluminium sheeting, combining the strength of steel with the corrosion resistance of aluminium. It also meets National Fire Protection Association guidelines for control of confined dust.

CONSTRUCTION IN JUST FOUR MONTHS

By early 2011, the design had been approved in Indonesia, and Geometrica had manufactured the components for the dome at its plant in Monterrey, Mexico. Geometrica labelled, pre-sorted, and packaged the components in the order required for assembly. Crates of these materials were then loaded into containers for shipment to the Port of Jakarta, Indonesia. From there, IKPT transported the containers to the job site in Tanjung Harapan.

Construction of the dome and stacker/reclaimer began simultaneously in June 2011. Assembly began at the top of the concrete wall and progressed toward the apex. The assembly, by 20 workers, assisted by two Geometrica consultants, took two months. The aluminium cladding was complete after another two months.

A SATISFIED NEW CUSTOMER AND A ‘GREEN’ SUCCESS

Geometrica met all of the expectations for this project, and Pupuk-Kaltim is pleased with the operation of the storage facility. The first coal drop into the new storage facility was on 21 May 2012. The dome is protecting the coal from rain and protects the environment from coal dust.

Today, Pupuk-Kaltim’s coal-boiler project is humming along, producing the steam required to help the company deliver its annual 3mt (million tonnes) of urea to its customers in Indonesia and beyond. And the shiny new Geometrica dome at Bontang keeps the coal, and the company’s track record, spotless.

ABOUT GEOMETRICA

Geometrica is an international firm based in Houston,Texas, USA that specializes in domes and space frames for architectural, industrial, and bulk storage uses. Geometrica provides the most striking and cost effective solutions for sports facilities, exhibition centers, passenger terminals, malls, assembly areas, production facilities, and many other buildings that require distinctive structures to cover great spans with no intermediate supports.

The domestic and international demand for US-origin metallurgical and thermal coal has dramatically changed in the last few quarters. The international demand for US export metallurgical and thermal coals has continued to grow in Europe and Asia at record levels, while US demand for domestic coal has fallen. For the past two years, Kinder Morgan has been focused on expanding a few key export terminals to keep up with the increased demand. At Kinder Morgan’s terminals, export coal volumes increased by almost 38% for the full year to a record of approximately 20.7mt (million tonnes) versus 2011. The increased volume was shipped primarily through the Pier IX terminal, with the International Marine Terminal (IMT) and the Port of Houston terminals seeing increases in volume during construction improvements which will increase the throughput capacity at the terminals.

PIER IX

IMT

Kinder Morgan is also investing approximately $400 million to expand its Gulf Coast terminal network. Kinder Morgan’s Gulf Coast terminal network is comprised of its partnership interest in the International Marine Terminal, which is located in Myrtle Grove Louisiana, the Houston Bulk Terminal and the Deepwater Export Terminal, both located in Houston,Texas. After completion of all of the export expansion projects, Kinder Morgan’s Gulf Coast terminal network will have a coal export nameplate capacity of approximately 27 million short tons per year. At IMT, Kinder Morgan and its partner,AEP River Operations,will invest approximately $170 million to increase IMT’s coal export capacity. The IMT terminal improvements include a new ship loader that will be capable of loading Capesize vessels. The improvements will also include a second continuous barge unloader, improved reclaim and distribution systems, and a dedicated barge loader for ocean going Gulf barges. These improvements will eliminate technical bottlenecks that have constrained the terminal’s throughput capacity in the past. Upon completion of the improvements, IMT will have an export capacity of 16 million short tons.

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One of the biggest changes on the Gulf Coast is Kinder Morgan’s ability to export coal out of the Houston Ship Channel. Kinder Morgan’s two Houston terminals, Houston Bulk Terminal and Deepwater Export Terminal, provide western producers with the ability to rail their coal directly to the export terminals as compared to railing material to the river and barging it to the lower Mississippi River.

Back stopped by long-term contracts with Peabody and Arch, Kinder Morgan is constructing improvements at its existing petcoke export terminals which will allow them to efficiently and economically export western coal. The first phase of the Houston Bulk Terminal expansion project and the interim improvements at Deepwater are completed, and both terminals will export coal in 2013. At the Houston Bulk Terminal, Kinder Morgan has constructed a new coal receiving, storage and reclaim system. Kinder Morgan is also upgrading the existing shipping system which will increase the terminal’s coal and petcoke export capacity. Upon completion of the improvements, the Houston Bulk Terminal will have the ability to export three million short tons of coal annually. The improvements at the

Deepwater Export Terminal include a new shiploader capable of loading post-Panamax vessels, new loop tracks capable of simultaneously holding three 135-car unit trains, a new rotary dumper, segregated distribution and reclaim systems, and a new shipping system. Following completion of the expansion, the Deepwater Terminal will have an export coal throughput capacity of 10 million short tons of coal per year.

In addition to the East Coast and Gulf expansions, Kinder Morgan continues to investigate and develop addition export terminal capacity in the Pacific Northwest and other markets for US coal producers, traders and foreign utilities.

SAFETY

All of the capital improvements will be designed and constructed to meet or exceed industry safety and environmental standards for similar facilities. Safety, environmental excellence and compliance, and commitment to our customers continue to be high priorities at Kinder Morgan. In 2012, Kinder Morgan Terminals recorded a Total Recordable Incident Rate (TRIR) of 1.58 which is considerably less than the industry average.

Telestack continues to innovate with regards to providing technical solutions to its clients on material bulk handling issues. One such innovation has recently involved the accurate blending of differing grades/qualities of coal within a power plant in South East Asia. In any given power plant stockyard, there will be various grades and specifications of coal which will have been sourced from various countries in various batch sizes.

Each of these grades will have a differing value of the following main material characteristics:

The challenge with any power plant operations team is how to accurately blend the various grades of coal with the above varying material characteristics to ensure that they are sending a consistent blend to the furnace.

Traditionally this blending has been carried out by using two stacker/reclaimers that feed onto a central conveyor which then sends the blended coal mix to the furnace. The main issues with this method of blending is that the blend ratios can vary dramatically and, as such, one of the stacker/reclaimers may be operating at a greatly under utilized rate.

This results in high operating costs per tonne for the process of reclaiming at these lower rates. For example: a power plant may want to blend an Indonesian coal of lower calorific value with that of an Australian coal with a higher calorific value. The total reclaim rate to the furnace is 1,400tph (tonnes per hour). If using a 80% Australian to 20 % Indonesian blend, then the stacker/reclaimer A is operating at 1,120tph while the stacker/reclaimer B is only operating at 280tph. The operating costs per tonne for stacker/reclaimer B as a result are excessive.

Also, the design of many power plant stockyards allows for both stacking of imported coal whilst unloading vessels and simultaneous reclaiming of coal from the beds to the furnace. However, when unloading vessels and stacking, a typical layout would incorporate two ship unloaders, and these would feed material to two stackers. This normally only leaves one stacker/reclaimer to send material to the furnace and, as such, blending cannot be carried out when unloading vessels. If reclaiming sub-bituminous coal, this can result in the de-rating of power generation.

This can also occur during periods when carrying out repair and maintenance on a stacker/reclaimer when the unit is not in operation. This can put additional pressure on other reclaimers when carrying out normal day to day reclaiming/stacking duties.

SOLUTIONS TO THESE ISSUES

Telestack listened to the issues facing the operations team of the power plant and worked in conjunction with them to offer them a unique and innovative technical solution to the above operational issues.

The Telestack TU1015R has a fully integrated feed hopper to allow the trucks/wheel loader to ‘dump’ and go, thus improving the cycles times and efficiency as well as allowing better control of the material onto the incline section. The integrated hopper is specially designed using a chain apron belt feeder which combines the strength of an apron feeder along with the sealing quality of a belt feeder.

The boom is radialled by a slew gearbox and drive, which turns on an external slew bearing on which the boom is mounted. This gives greater control when positioning the boom over the reclaim line and, combined with the luffing ability from 0–23°, this allows the operator to place the boom precisely.

The Telestack design ensures versatility in that it can be fed by front end loader/excavator or trucks. When reclaiming the machine is fed by one or a combination of above and can be set at pre set percentage ratios with the touch of a button.

The Telestack TU1015R can work in conjunction with a stacker/reclaimer to send an accurate blend to the furnace. The unit incorporates a dual idler belt weigher which is connected to a PLC on the machine; this PLC controls the feed rate to the reclaim line and can be linked to the central control room via an ethernet connection or a Wi-Fi communication system.

The 1015R can also be utilized for following duties within the stockyard: 1. stacking in passive areas — where the stacker/reclaimer cannot reach; 2. interyard transfer of coal from one heap to another via stacker/reclaimer; and 3. emergency reclaiming in event of breakdown/ or planned maintenance of stacker/reclaimer.

In summary, the machine can be used to compliment existing fixed stockyard infrastructure and can give the operations team additional capacity for reclaiming and flexibility with regards to stockyard management.

Liebherr has launched its range of maritime crane simulators. Based on original software and hardware, the Liebherr simulators increase safety and productivity by providing a cost-effective and highly efficient crane operator training solution. These simulators are suitable for training operators handling a wide variety of commodities, including coal.

The development of this advanced training tool is driven by Liebherr’s extensive experience in highly immersive crane driver training. Approved by training experts, the range of simulated cranes includes ship to shore, rubber tyre gantry, mobile harbour and offshore cranes.

FOCUSING ON EFFICIENCY, SAFETY AND COSTS

Successful companies are continuously looking for efficient ways of up skilling their employees at the highest safety level while costs including time are kept to a minimum. Liebherr Simulations (LiSIM®) offers sophisticated solutions that tick all the boxes, allowing trainees to significantly improve their skills in a realistic but virtual maritime environment.

Thanks to the virtual environment, damage to maritime equipment and injuries to personnel are eliminated. Because training does not interfere with day to day operations and is relatively inexpensive, trainees can spend extended time in the virtual environment, learning instinctively how to react to unexpected situations. This naturally increases safety in real cargo and container handling.

A major benefit of simulator training is the ability to simulate harsh environmental conditions when required. This allows both experienced operators and trainees to gain valuable experience operating under challenging conditions in a safe environment. The resulting increase in operator skills allows for safe and productive crane operation under similar conditions in the real world, boosting productivity. For example, even though it may be a calm and sunny day, the trainee can practise cargo handling in harsh weather conditions such as snowfall, heavy winds, torrential rain and high waves.

The sophisticated LiSIM^® environmental and physics engine allows for an unprecedented level of detail and realism. Thanks to this non-destructive virtual environment, the operator has the opportunity to learn the operational boundaries of the crane without any consequences, gaining useful experience for highly efficient crane operation.

Simulator based training avoids costly downtime and reductions in productivity caused by on-crane training. The emission and fuel-free LiSIM^® training solution is in line with an eco-friendly maritime operation. Moreover, expensive delays in training caused by poor weather conditions are eliminated. Thanks to well-trained operators, simulators have the potential to significantly reduce accidents. Simulator-based training is recognized as a cost-saving and safety improving measure.

ORIGINAL SOFTWARE AND HARDWARE

Trainees benefit from the ergonomically designed driver’s cabin and control panel. The motion platform ensures that the driver in a Liebherr simulator cabin experiences realistic movement which mimics precisely the response and feel of a crane mounted driver’s cabin and seat. Full high-definition flat screen monitors and high quality surround sound speakers reproduce the views and sounds typically experienced in the cabin.

Liebherr simulators are available in three configurations. The classroom solution is easily integrated into existing training centres with the display, seat and controls mounted on a base and a sturdy display frame. The space-saving cabin solution ensures that the driver becomes familiar with controlling the crane in a real life environment. The easy-to-transport containerized solution houses the simulator in a 40ft container and features a training room, utility room and cabin simulator. Each of the three models is equipped with multifunctional instructor stations.

COMPREHENSIVE FUNCTIONALITY

In view of the varied situations which occur during cargo and container handling, comprehensive functionality is indispensable when guaranteeing an authentic simulation. Each realistic LiSIM^® scenario is set in a typical maritime environment where numerous parameters can be modified according to training requirements, including day-time or night-time operation, weather

conditions, kind of cargo and vessel size. Additional parameters allow for the simulation of virtually any kind of cargo or container handling situation. The implementation of customized maritime environments and layouts is also possible.

The multifunctional instructor station has complete control over the simulation. Thus, the instructor has the possibility to create challenging and unexpected situations for the trainee at any time. This includes heavy wind or lift object faults for example. LiSIM^® has database and performance metric functionality so it is possible to track the progress of the students over time.

SUCCESSFULLY PRE-TESTED AND NOW AVAILABLE

Liebherr’s training simulator has already proven its capabilities and worth in training centres and at various exhibitions, representing one of the major attractions at the TOC Europe and the Intermodal Sao Paulo. Now this state-of-the-art training solution is available for customers all over the world who want to improve efficiency in container or cargo handling combined with increased safety and reduced costs.

Back in the mid 1980s UK researchers started the development of a fully on-line instrument for measuring the ash content of conveyed coal, writes Paul Michael Taylor. This fledgling instrument, using natural gamma technology, was called the Natural Gamma Coal Quality Monitor (NGCQM) (Wykes et al, 1989). In 1994 Bretby Gammatech was formed to continue this work. Over the years the NGCQM has been progressively developed and is now known as the Ash Eye (Taylor et al, 2013).

In the late 1990s there was a requirement for a hand portable ash monitor. The Ash Probe was developed to meet this need. The development and application of the Ash Probe has been outlined previously (Taylor 2000 & 2010). This stimulated the development of the Lab Ash which is a laboratory instrument providing a quick ash measurement from a ~10kg sample of crushed coal (Taylor 2002). Both these instruments use natural gamma technology (NG).

The single most significant advantage of NG is that it requires no radioactive sources — it relies solely on the natural gamma emissions from the shales and mudstones associated with mined coal being greater than those emissions from the coal itself. For most coals this property holds true, albeit there can be variations from coal source to coal source. This article describes the technical details of the latest NG instruments including the applications and benefits that can be derived from their good use.

BRIEF DESCRIPTION OF NATURAL GAMMA

The natural gamma technique for the measurement of the ash (or non-combustible mineral content) is well documented (Wykes et al 1989). In summary, the technique relies on the fact that the ash forming shales and mudstones associated with mined coal contain a higher concentration of naturally occurring radioactive isotopes than the coal itself. The principal contributing isotopes are Potassuim40 and members of the Uranium and Thorium radioactive series. The level of gamma radiation emitted from a given weight of mined material increases monotonically with its ash content. Thus the count rate from a sensitive gamma detector placed close to a given mass of coal is well correlated with the ash content of that load. Of course, the gamma count rate is also correlated with the mass of the load but this relationship is non-linear. The increase in countrate falls off as the mass loading increases due to self absorption of the gamma energy (Wykes et al 1989). Thus for an on-belt system where the mass loading is variable, a tonnage and a belt speed signal from a belt weigher are required.

The mass loading is not an issue with the Ash Probe because the sensor, located at the tip end of the probe, is buried deep into the pile of coal and is effectively saturated with gamma counts. This geometry has further advantages because the effect of background variations are minimized due to the attenuating effect of the intervening coal. The ash content is calculated directly from the gamma counts sensed by the probe.

With the Lab Ash a lead shielded chamber is used to minimize the effects of background.

THE ASH EYE

Small variations in background radiation can and do have a detrimental effect on the performance of a simple NG ash monitor. The Ash Eye uses a sophisticated background compensation algorithm to overcome this limitation.

The Ash Eye can be used for many different applications. The main ones are:

THE HEAT EYE

THE ASH PROBE

The Ash Probe is a hand portable instrument for measuring the ash content of coal in piles, wagons or trucks. It comes in two main parts, the probe and the display unit (DU).

There are many applications for the Ash Probe but the main ones are:

Due to the portability of the Ash Probe there are often multiple applications at the same site.

THE LAB ASH

The Lab Ash is a laboratory instrument for measuring the ash content of small samples (~10kg) of coal. It comprises two parts: a sample measuring chamber and a display unit. The sample chamber is a substantial lead walled cylinder containing a scintillation crystal and associated electronics. The crystal is positioned vertically in the centre of the chamber so that when a special beaker containing the coal sample is lowered into position the crystal is evenly surrounded by the sample. The mains- powered display unit provides the user interface and is housed in a case suitable for desk or bench top operation.

CONCLUSIONS

Over the past 25 years the natural gamma technique has become established as one of the main technologies used for the rapid measurement of the ash content of coal. The on-belt Ash Eye is rapidly gaining in popularity around the world with 14 units sold in the past year alone. The Ash Probe remains the flagship instrument with over 230 in operation in over 20 different countries around the world. The Lab Ash is also gaining acceptance in several countries but most notably Russia.

The take up of this technology is very likely to increase in the future. This is due to the quick and accurate results that these instruments can provide. The fact that there are no radioactive sources is also becoming an increasingly attractive feature in these environmentally cost conscious times.

REFERENCES

Taylor, P. M. and Wykes, J. S., The Natural Gamma Technique for on-line coal quality monitoring – Five years field experience in the United Kingdom. Journal of Coal Quality,Vol. 12, No 2–3 April–September 1993.

Taylor, P. M.,An All Natural Technology, World Coal,Vol. 9, No 1 January 2000.

Taylor, P. M., Natural gamma technology in practice, World Coal, Vol. 11, No 12, December 2002.

Taylor, P. M., Natural gamma comes of age for the quick measurement of the ash content of coal in piles, wagons and trucks – Some case histories, Proceedings of the XVI International Coal Preparation Congress, 689-698, 2010.

Taylor, P. M., Natural Gamma for the on-line measurement of the ash content of conveyed coal – 25 years of success.To be presented at the XVII International Coal Preparation Congress, Istanbul, October 2013.

Wykes, J. S., Hoddy, J. D., Adsley, I. A., Croke, G. M., and Haines, G. J., On-line monitoring of the Ash Content of stone/coal loads using Natural Radiation, Nuclear Geophysics, 3(3), 203, 1989.

Eriez is recognized as a world authority in separation technologies, writes Sarah Grain, Export Sales Manager at Eriez. The company designs, develops, manufactures and markets magnetic separation, metal detection, materials feeding, conveying and process equipment for use in a variety of industries, including process, mining, aggregate, metalworking and recycling.

When it comes to the coal processing sector, Eriez is a one-stop solution thanks to its range of magnetic separators, metal detectors, feeders, wet drums and other processing equipment. Working closely with end-users or engineering companies, Eriez focuses on providing an optimized solution for customers’ processing problems.

One of the primary products for this industry sector is the suspended magnet for removal of tramp iron from coal on conveyor belts. Eriez’s extensive range of both standard and custom design suspended electromagnets ensures that customers have a suitable option for all separation requirements and budgets. Eriez standard range of suspended electromagnets is typically naturally oil cooled, but Eriez also offers a special custom design service for difficult applications where large belt widths, high belt speeds and high capacities make removal of tramp iron a big challenge. Eriez is able to offer force cooled magnets, which use additional cooling of the electromagnetic coils to enable more powerful magnets to be manufactured within space and budget limitations. Eriez offers both manual and self-cleaning versions of its suspended electro magnets and these can be installed either across the belt at 90o to the product flow, in a diagonal orientation at approximately 45o to the material flow to aid with the removal of long rods and bars or above the discharge point of the conveyor. The choice of magnet model, location and performance is decided upon in close discussion with the customer, to ensure that the equipment offered matches both customer expectations and industry requirements. Eriez suspended electromagnets are in use in coal processing applications worldwide and can be customized to suit all local environmental factors, including extremes of temperature, altitude and operating conditions.

These Eriez electromagnets are manufactured throughout the Eriez family of manufacturing affiliates, enabling Eriez customers to benefit from a choice of manufacturing locations.

This is the world’s strongest suspended magnet and goes hand in hand with the Eriez Guinness Book of World Records award for manufacturing the world’s largest electromagnet at around 60 tonnes. That particular magnet is in use in Chile at the Radomiro Tomic copper mine.

Eriez metal detectors for the coal processing industry are used in conjunction with suspended electromagnets to ensure that coal processing lines have secondary protection from damage by both magnetic and non- magnetic metal contamination. Their primary purpose is to protect crushers and belts at transfer points from costly damage by tramp metal. Eriez’s metal detectors are designed for easy installation on existing conveyor systems, without cutting the belt. They are custom-built to suit any belt width and in a design that is extremely robust and suitable for outdoors use in difficult operating conditions.

Eriez can offer both suspended magnet and metal detectors that comply with current ATEX requirements, in keeping with the changing demands of the sector.

To assist the coal processors with the reclamation of magnetite or ferrosilicon in heavy media applications, Eriez offers a comprehensive range of wet drum separators. Eriez wet drums typically offer >99% recovery of magnetite or ferrosilicon with a design that can handle fluctuations in slurry flow and magnetite content. Eriez wet drums are available in various diameters, widths and tank designs to meet different operational challenges, including the latest innovative self-levelling design.

Eriez also offers a comprehensive range of other equipment for use in the coal processing sector, including heavy duty, high capacity mechanical and electromagnetic vibratory feeders, Crossflow^® Teeter bed separators for run-of-mine coal and state- of-the-art CoalproTM column flotation cells for the recovery of fine coal, to name but a few.

With over 1,000 direct employees in its worldwide network of manufacturing facilities and test laboratories coupled with over seven decades of manufacturing and its network of experienced, factory-trained representatives, Eriez continues to reinforce its position at the forefront of this sector by offering innovative products and service to the industry.