Impacts of Open Stockpile on Fugitive dust emissions

Diminishing dust levels at a bulk storage material handling operation is a requirement driven by a combination of environmental, operational, employee and community expectations.

Within an operation, dust adversely affects employee health, visibility and adds a variety of maintenance challenges. Externally, the irritation caused by fugitive dust can have a major impact on communities in the vicinity of the stockpile.

The best possible solution to overcome these dust issues is to cover the open stockpiles. Hindustan Alcox designs long span dome structure and vaults that cover stockpiles, prevent runoff, contains dust and spare landscapes. Your operations, employees and landscapes are protected against fugitive dust.

Hindustan Alcox offers a practical solution that saves both time and money. Our Assembly process ensures a fast, safe and easy installation of these dome structures. With expert guidance, our structures are installed with all safety measures. The benefits of covering stockpiles as compared to open stockpiles are as follows:-

·                     Minimum dust emission in the stockpile

·                     No air pollution

·                     Elimination of caking problems in stockpiles

·                     Elimination of rainfall and moisture problem

Stocking of product in covered storage system not only minimizes the above various problems, but also improves plant efficiency and maintains quality of the product.

About Hindustan Alcox Limited

With over 30 years of experience, Hindustan Alcox Limited is the leading dome structure manufacturer. Design and functionality are hallmarks of Hindustan Alcox. Regardless of climate or geography, we solve dust problems with endless design options. Our mission is to provide solutions for coal storing industries all around the world.

Read More - Types of Tensile Membrane Structures

Popular Facts about Dome Structures

A dome is typically an element of architecture that resembles the upper half of sphere. Dome structures are curved – they have no angles and no corners – and they enclose an enormous amount of space with the minimum of materials as they don’t require interior supports. Despite their slenderness, dome structures are some of the strongest and stiffest structures in existence today. There is no denying that the domes are amongst the strongest architectural forms to have been developed in the construction industry. Listed below are some important facts about dome structures that have revived their demand in the modern construction industry:-

·  Bulk storage domes are extremely efficient and cost effective structures as they are lighter in weight as compared to other building styles. In addition they can be constructed with significantly lesser material and provide a much longer life.

· The absence of any corners, angles and flat surfaces make these structures highly resistant to high pressure winds and hurricanes. This is because the winds are able to pass smoothly over their circular shape while creating minimal turbulence due to excessive air pressure. This makes dome structures aerodynamically stable.

· Most modern buildings having dome shaped structures use the geodesic domes which are specially engineered for efficient utilization of space besides making the construction highly economical.

· Given the inverted circular design of the dome shaped structures, the dissipation of energy is also carried out in a highly efficient manner. This means that the various sections of structures can be rapidly heated and cooled in an even manner.

About Hindustan Alcox

With over 30 years of experience, Hindustan Alcox Limited is one the leading dome manufacturers. We use the latest technology to create aesthetically appealing structures that offer the benefits of long life and economical construction.

Read More -   Types of Coal Storage Sheds

Dome Structure – Why are domes important in construction industry?

A dome is an element of architecture that resembles the hollow upper half of a sphere. Dome is a rounded vault mode of either curved segments or a shell of revolution, meaning an arch rotated around its central vertical axis. Dome structures made of various materials and has an architectural lineage extending into prehistory.

Importance of Dome structure in construction industry:

• High Strength: Dome structures are highly durable and strong. If we talk about stability and average building life of dome structures, their life is longer and stability is more than any other type of structure in steel structure industry.
• Very Low Maintenance: Dome structures are comparatively easier to maintain than any other building primarily due to the curved geometry, therefore the cost of maintenance on these structure is lesser.
• Resistant to adverse weather condition: Due to its hemispherical Structure and absence of angles, flat surfaces makes them highly resistant to adverse weather condition such as Earthquakes, cyclones etc.
• Extremely Energy Efficient: Bulk Storage dome structure does not need any interior support and thereby wide space inside them cater them the benefit of more storage. Moreover, there is substantial reduction in the weight of material that Is utilized leading to lower carbon footprint.
• Good Acoustic Quality: In Most of the places where sounds need to travel in continuous manner, dome structures are more preferable as compared to other structures due to good acoustic nature.

Due to these great benefits, dome structures are highly preferable in the construction industry.

About Hindustan Alcox

We at Hindustan Alcox Limited, one of the dome manufacturers in India, use the combination of its key features and latest technology make these structure more engaging and highly versatile in installation as well as in maintenance.

Read More - Industrial Shed – Pre Engineered Buildings

Coal Storage Domes integrated with Coal Gasification: An Ideal Storage Solution

Coal Storage:

For a fruitful outcome of thermal Power Plants, the business of industrial coal storage for large quantities is on top priority for maintaining the product Integrity. Open stockpiles leave materials subject to degradation during storage. In addition, there are environmental concerns with controlling dust and runoff from these coal stockpiles.

Coal Storage Domes integrated with Coal Gasification:

Conversion of coal by the chemical processes to produce a mixture of combustible gas or fuel gas or syngas is termed coal gasification. Coal Gasifiers generally entails the controlled oxidation of the coal to convert it into desired gaseous products. The emphasis of coal gasification is to meet stringent emission control requirements.

Bulk storage dome structures are highly durable and strong. If we talk about strength and average building life of dome structures, then their life is longer and strength is more than any other type of stacker reclaimer sheds in Space frame industry. Coal storage domes with coal gasification has its own advantages. These include:

• Simple foundation requirements.
• Rapid construction regardless of weather.
• Condensation is virtually eliminated.
• Better environmental and fugitive dust control.
• Environment Friendly.

Dome Structural system provides a unique solution to the bulk storage industry. Remained committed towards sustainability and improving the local economies, the coal dome manufactured by Hindustan Alcox Limited are strong, durable, environmentally sound and adaptable. Over Last 20 Years, Our capabilities as a "prime industrial shed manufacturer" include building the Bulk storage dome shell for providing turnkey solutions all over the world.

• Hindustan Alcox Limited, New Delhi
  (Coal Storage Sheds Manufacturer in India)

Coal Storage: Performance Requirements for Maximum efficiency

Coal Storage:

Coal is a fossil fuel just like oil and natural gas. In thermal power plants, coal storage or petcoke storage (as the most exploited solid fuel) at large scale is preferred for the production of electric energy. A good preparation of coal before its combustion increases the homogeneity and efficiency of the fuel, reduces transportation costs and its displacement inside the plant produces less dust and reduces the emission of sulphur oxides. Besides, Preventive measures should be taken at every stage during the transport and bulk storage, in order to reduce any environmental impact, so that it became easier to maximize plant efficiency without any interference of any outside or environmental effects.

Performance Requirements for Maximum efficiency:

The large investment in a thermal power plant should be protected in best pos­sible way by maintaining the quality of resources (like coal, petcoke, lignite etc) and by uplifting the performance of their handling system. The coal handling system and equipment should perform satisfactorily to meet the guaranteed performance for maximum efficiency as stated here under:

1.      Efficient operation in thermal power plants means the careful use of fuels and other consumables resources includ­ing in-house consumption of electricity. High availability requires strong focus on maintenance, which in turns contribute as one of the factors in producing maximum efficiency.

2.      Stacker or reclaimer should be stable under a specified design condition and meet all the specified requirements. During unfavorable environmental conditions, the stacker or reclaimer should reclaim the coal in a way to avoid generation of well compacted, damp and sticky coal.

3.      Sulphur content in fuel always had an adverse effect on overall plant efficiency. ‘Corrosive acids formation’ and ‘heat loss in boiler’ can be evaded by properly supervising and removing the sulphur content in coal.

4.      Condition based maintenance uses intelligent measurements and assessments. These can include oil quality, differential pressure measure­ments, vibration readings and many more. By such applications, maintenance and renewal of plant components can be done exactly when needed.

5.      Fuel quality of coal, which is generally quoted in terms of its gross calorific value (GCV) along with its moisture and ash content impacts on whole plant operational efficiency. Assessing fuel quality and choosing fuel of maximum gross calorific value and less moisture & ash content improves combustion and power generation as well.

6.      Variation in the ambient temperature tends to affect plant performance and load capability of gas turbines along with the performance of cooling system. Hence, it is better to maintain the ambient temperature near a specific threshold during plant operation for maximum power output.

Using long-time experience of 30 years, It has been challenge for Hindustan Alcox Limited to identify and eliminate unnecessary energy losses from the processes by providing the best choice for covering coal stockpiles under Coal storage shed. Alternatively, Coal Storage and handling can be done under dome structure sheds (like Coal dome, petcoke dome).

  

--   Hindustan Alcox Limited, New Delhi

(Coal storage Shed Manufacturer)

Handling & Maintenance of Petcoke Storage in Captive Thermal Power Plant

Storage of Petcoke­: 

Coke is a fuel made from coal with high carbon content and few other impurities. Petcoke (or Petroleum Coke) is fuel derived from its oil refining. The captive thermal power plants exploit chemical energy of the petcoke and convert it into into electrical energy. That is why maximum requirement of fuel in thermal power plants is of coal. The petcoke storage at a large scale is needed to deliver in the storage yard through transportation. The modes of coal transportation include railroad, pipeline, barge, truck, and conveyor for domestic movement, plus ship movement for overseas. Then the petcoke is dropped in a coal yard and usually stored in stockpiles. The Petcoke Storage plant in a thermal power station covers unloading, its crushing, storage and filling of boiler bunkers.

Risks to petcoke/coal storage & their proper handling in Thermal Power Plant:

Global warming and other environmental factors such as oxidation at low temperature, microbial metabolism, absorption & desorption of water by virtue of differences between real and equilibrium moisture content in coal and air causes some risks to coal storage. These risks include ‘self oxidation of coal’, ‘increase in moisture content’, ‘spontaneous combustion’, ‘flow blockage’ etc.

In a Captive thermal power plant, the foremost and effective process to avoid the risks to coal storage in the power generation is “Coal Handling”. Coal handling includes bunkering of coal, stacking & reclaiming of coal. Giant Stackers may be used to form two different patterns- ‘cone’, ‘chevron’ either on one or both sides of stacker.  Stacking and reclaiming of coal is not only limited to avoid risks (such as spontaneous combustion,  self oxidation, caking problem) to coal stockpiles but it must be carried out in such a way to keep coal effective to feed the boiler and in turn optimized power generation.

Maintenance of petcoke/coal stockpiles for Productive Outcome Power:

Besides the proper storage and handling of coal up to a remarkable extent, the maintenance of coal stockpiles for long term use play an crucial role by resulting an optimized power production.  Maintenance of coal stockpiles for Productive Outcome Power can be upheld by considering the following points:

·        Coal dome or Petcoke dome should be constructed in such a way to prevail cross ventilation at every corner inside it which, can be done to prevent heat accumulation as well as to maintain the quality of stockpiles for a long term. Besides, Coal dome provide best protection against moisture and rainy weather since coal is vulnerable to moisture.

·        Monitoring height and orientation of stockpiles: Routine surveying of stockpiles in term of their heights and orientation should be done using infrared devices and/or sensors where spontaneous combustion is more likely to occur. Storing coal in form of many smaller stockpiles is a great idea.

·        Autonomous Stacking & Reclaiming: The coal can be stacked and reclaimed by various methods like (windrow, chevron, cone-shell etc) in order to provide an adequate treatment to the material as well as the long-term maintenance of coal stockpiles for efficient power outcome.

·        Coal Quality Management:  The system of coal quality management is equally important while maintenance of coal stockpiles is our priority. To examine coal quality, the parameters like (calorific value, density, ash content, moisture content) are the prime.

·        Material Tracking:  The enhanced degree of efficiency of modern coal power plants calls for an integrated coal material tracking system in order to secure the coal supply in the requested quantity and quality. For an efficient material handling system, the Coal should be traceable anywhere, even in a surge bin, on a belt or on the stockpile.

Hindustan Alcox Limited, the well-versed & proficient organization emerged as India’s apex coal storage shed manufacturer holds a tremendous experience of over 30 years in producing Coal domes & storage sheds. Depending on different factors like geology, demographics, climate etc we provide the best feasible & competitive Bulk Storage dome solutions such as Petcoke dome and Coal dome.

-          Hindustan Alcox Limited, New Delhi

(Coal Storage Shed Manufacturer In India)

Role of Gypsum storage in FGD/Flue gas desulphurization unit

Gypsum storage:

Finely grinded form of calcium sulphate / CuSo₄.2H₂O material industrially used for enhancing adhesive strength of the cement, called as gypsum. Gypsum Storage at large scale is needed since it is one of the prime resources in the cement industry. In purpose to improve cement’s inherit qualities, performance and efficiency, a composite gypsum storage solution needs to be followed systematically:

Gypsum Handling System:

Gypsum handling includes bunkering of gypsum, along with its stacking & reclaiming in a very cautious way. Large Stackers are used to form two different patterns- ‘cone’ , ‘chevron’ either on one or both sides of stacker. Stacking & reclaiming of coal is not only limited to avoid risks (such as spontaneous combustion, self oxidation, caking problem) to coal stockpiles but it must be carried out in such a way to keep coal effective. Gypsum is usually stored under well-constructed sheds ensuring its storage without deterioration and without contact to ground and structural members, without exposure to moisture and heat, and away from direct sun.

For environmental friendly gypsum storage and production of an best outcome in cement industry, today almost all out-performing cement plants use to store gypsum stockpiles under a strong, durable, eco-friendly and solution-rich gypsum storage shed and gypsum dome. 

Role of gypsum storage system in FGD/ Flue gas desulphurization unit:

The resources like coal, petcoke, limestone contain a significant amount of sulphur into them. In many large scale power plants and cement plant (where the resource is Coal, petcoke, limestone etc), the problems arises from boiler or furnace where large volumes of So₂ accumulation not only deteriorates air quality of environment but also highly corrosive for handling equipments like stacks, fans etc.

In order to extract So₂ from flue gas, the mechanism of extraction employed is known as FGD or Flue Gas Desulphurization. In Flue Gas Desulphurization, the chemical Techniques are used to exclude sulphur di-oxide (So₂) in exhausted flue gasses from the Furnace/boiler. Some of the Chemical techniques used for FGD are 'Wet Scrubing', 'Dry Scrubing', 'SNOX FGD' etc.

The output from flue gas desulphurization is synthetic gypsum, which is carried out under FGD shed. For cement manufacturing, this FGD storage product or synthetic gypsum is supplied in crushed form for further fine grinding with cement clinker and has many other commercial applications in cement industry, bricks manufacturing etc.

-         Hindustan Alcox Limited, New Delhi

(Gypsumstorage shed manufacturer In India)

Gypsum storage – Moisture Problem & Their Control Strategies

Gypsum Storage:

In cement producing plants, a widely used fine-grained calcium sulphate (CuSo₄) material used as binding agent is “gypsum”. In cement plants, gypsum is used as one of the prime materials to provide premium performance and superior aesthetics for a wide range of occupancies. Such material shall be stored in properly constructed sheds ensuring its storage without deterioration and without contact to ground and structural members, without exposure to moisture and heat, and away from direct sun.

Moisture / Caking problem in Gypsum Storage

Materials required in construction operations shall be stored, and handled in a manner to prevent deterioration and damage to the materials, ensure safety of workmen in handling operations.

In context of gypsum storage in cement industry, Moisture control is one of the complex handling issues. Moisture ingress in gypsum stockpiles should be controlled not only to promote the wellbeing of occupants but also the sustainability of a building to be constructed. Moisture Problem in gypsum storage not only linked to potential health problems, including increased risk of respiratory conditions resulting from exposure to mold, microbial agents, dust mites, but also can negatively impact durability, maintenance, aesthetics, and serviceability.

Moisture Control Strategies for Gypsum storage:

Many factors must be considered to ensure no moisture in gypsum stockpiles.

·        The foremost step regarding moisture control strategies for gypsum storage is to address all potential sources of water intrusion and then to offer all viable solutions for its prevention from moisture.

·        Materials subject to loss of quality through moisture should be kept within impermeable wrapping, if not used within a reasonable period.

·        Integrating the air and /or vapor retarder with the penetrations helps to restrict air and vapor flow, resulting in reduced moisture problems. Air control highly need to have structural continuity, while vapor control can be accomplished using a variety of other materials.

·        Dehumidification involves the withdrawal of moisture from the air to lower its relative humidity. This generally becomes necessary during wet monsoon months to facilitate production processes and prolonging storage life of gypsum and other additives in bulk.

·        The roofing system is a vital part of the exterior weatherproofing envelope and is comprised of a multitude of steel materials and components. It is crucial that ceiling and penetration of roofing systems be properly designed & installed to provide better performance. Therefore, Gypsum stockpiles should be stored at the work site in a building or a storage shed which is dry, leak proof and moisture proof.

Gypsum storage sheds engineered by Hindustan Alcox Limited is the most advisable choice to cover gypsum stockpile for the adverse environment conditions. We, at Hindustan Alcox Limited provide storage solution for gypsum with long span steel structure having span of up to 150 m & height of up to 40 m. Besides barrel vault structure, Gypsum dome also provides an opportunity to achieve good plant efficiency by maximum space utilization and hasty operational works.

-         Hindustan Alcox Limited, New Delhi

(Gypsum Storage Shed Manufacturer)

Coal Storage: Problem of Spontaneous Combustion & Its Prevention

Coal, a non-renewable combustible material composed of carbon and hydrocarbons, whose combustible quality can be used for electricity generation and for some other necessities. Although stacking of coal is done in open shed areas, there are also covered shed areas or completely closed coal dome or silo.

Spontaneous Combustion of Coal ?

Spontaneous combustion of coal stockpiles

Many issues have been encountered in bulk storage but in case of storing coal, self-combustibility comes as a special case & need careful treatment. The Spontaneous Combustion of coal in the coal storage is serious issue now a days due to global warming and other exothermic processes in coal stockpiles such as microbial metabolism, oxidation at low temperature, absorption & desorption of water by virtue of differences between real and equilibrium moisture content in coal and air. Spontaneous combustion usually begins as "hot spots" deep inside the coal/petcoke storage. They appear when coal absorbs oxygen from the air & heat generated by oxidation initiated the fire.

Key Causes of Spontaneous Coal Fires

The risk from spontaneous combustion or coal fire persists where significant amount of coal are in use or storage. The following mentioned points have been the contributing causes of spontaneous coal fires:

·        New piles of coal added on top of old coal stockpiles creating segregation of particle sizes and become the major cause of heating.

·        Too few temperature probing techniques or sensors installed in bunkering of coal resulting an extension in the time period before the fire was detected.

·        Equipments’ failure to fight the coal fires (such as drag chain conveyer).

·        Ineffective use of “Carbon dioxide fire suppression system” in plant area

·        Delay in the application of water.

·        Inadequate training of personnel, improper implementation of policies, & procedures prevented proper decision-making, including the knowledge to immediately overcome the coal fire.

·        Long-term retention of coal in coal handling procedures also increases the probability of increase in temperature.

Preventing  Spontaneous Combustion in coal stockpiles-

Preventing spontaneous combustion involves attention to many different factors, are as follows:

·       Sulphur in coal liberates ample heat when they oxidize. Hence, strategies like “Know your Coal” & “Storing coal with low sulphur content” are helpful in evading spontaneous combustion in the plant area.

·       Air circulation within a coal stockpile should be avoided up to possible extent since this supports increase in temperature in the stockpile.

·       Use coal as quickly as feasible. The longer large coal stockpiles are allowed to sit, the more spontaneous combustion process dominates and increase the chances of coal fires.

·       Do Proper inspection, test & maintenance of installed fire protection equipments on site.

·       Following the "first in, first out" rule in coal stocking and stacking under petcoke dome or storage shed reduces the chances for hot spots in stockpiles by dissuading heat buildup for portions of stockpiles, which remain undisturbed for a long term.

-         Hindustan Alcox Limited, New Delhi

Gypsum storage sheds: In-plant Handling & Service

Gypsum storage:

Gypsum is fine-grained calcium sulphate (CuSo₄) material industrially used as binding agent and a prime consumer in the cement industry. Gypsum is produced from open-cast mines, or underground mines using pillar and stall mining methods. For cement manufacturing process, Gypsum is supplied in crushed form for further fine grinding with clinker.

The Gypsum Industry is consistently working towards its building value for society by offering creative, safe, recyclable & economic products for the homes. Moreover, the cement industry is using gypsum storage in controlled composition as additives to improve cement’s inherit qualities, performance and efficiency.

FGD or Flue Gas Desulphurization is another application of Gypsum storage in which the desulphurization process takes place when the flue gases are brought into contact with an aqueous suspension containing powdered limestone or quicklime. The SO2 is washed out by the water and oxidized to SO3 in the aqueous solution, and precipitated to get gypsum.

In-plant Handling of Gypsum storage:

Stockpiles of gypsum are very heavy and can become unstable if proper stacking and handling procedures are not followed. Special care must be taken while loading, securing shipments, warehousing, or handling gypsum. Heavy equipment are generally used to move, stack, load, stock, or handle gypsum storage. A large machine that is used in performing almost all in-plant handling operations, is Stacker or Reclaimer. The stacker is mainly used to produce efficient industrial outcome by avoiding problems like increase in moisture, caking, oxidation etc. In addition to stacker or reclaimer, Lift trucks are also used to move heavy stacks of gypsum.

Exposure of gypsum stockpiles to rain and other high moisture levels may result in water stains, discoloration, particle segregation & sag. To evade such problems, Hindustan Alcox Limited provides gypsum stockpile sheds with highest quality standards ensuring safety and reliability which ensures the safety of stored resources.

Services We Provide:

Hindustan Alcox Limited offer the gypsum storage solutions with economical and ecological aspects which will also comply with future demands. Along with Best possible safety standards in all functions, we provide storage solution with worldwide proven technology, reliability & quality. We provide -

•         Highest quality standards ensuring safety and reliability
•         Efficiency and profitability 
•         Intra-plant quality assuring systems
•         Commissioning with highly qualified supervisors
•         Worldwide After-Sales Services

-         Hindustan Alcox Limited (Gypsum storage shed manufacturer in India)