Coal drier dryer

Types of coal drier dryers

A coal drier dryer is used to dry the moisture content of coal to achieve a better heating value, which increases the selling price of the product. Different types of coal drying technologies include thermal drying, microwave drying, solar drying, and chemical drying.

• Thermal drying: The thermal drying method is the most commonly used methodology by industrial plants. It uses heat transfer through the direct or indirect contact between the coal and a drying agent. The drying agent can either be heated air in the atmosphere or steam. In direct contact, hot gas flows through the coal or vice versa. In indirect contact, a heated surface carrying the coal is used.
• Microwave drying: Microwave drying works by applying electromagnetic waves that are absorbed by the coal, creating heat that dries it in the process. Microwave coal dryers are different from conventional dryers where heat must be transferred to the object.
• Solar drying: In solar drying, the solar energy collected is used to heat the air that in turn dries the coal. This kind of drying process relies heavily on the weather conditions so it is usually combined with other drying methodologies.
• Chemical drying: Chemical drying occurs when the coal is treated with chemicals designed to lessen the moisture content. Coal is usually submerged in the chemical solution, which can also be known as drying agents, for a certain period.

Other types of coal drying technologies include superheated steam drying, biological drying, flue gas drying, flash drying, fluidized bed drying, spray drying, vibrating drying, electrokinetic drying, freeze-drying, and rotary drying. Some of these methods are not commonly used or are still in experimental stages. For example, the electrokinetic drying method uses electrical force to move water from the coal, while the freeze-drying method removes the water by sublimating it from the coal.

The efficiency of coal drying can vary depending on the coal drying technology used. Thermal drying is the most efficient method with the highest recovery rate, but it consumes a lot of energy.

Specification and maintenance of coal drier dryers

Specifications

The specifications depend on the specific type and model of the coal drier or dryer.

• Length and diameter

  The length and diameter of a coal rotary dryer tend to range from 30m to 200m and 1.5m to 4.5m respectively. For some models, the length is 5 to 10 times the diameter. Additionally, the dimensions of a dryer will be larger if its production capacity is higher.

• Production capacity

  A typical coal dryer machine can achieve production capacities of over 5 tons per hour. For some larger models, the capacity can be more than 50 tons per hour.

• Temperature

  A coal dryer can increase the temperature of damp coal by 200°C to 600°C. The temperatures in some flash dryers can be even higher, reaching 1,200°C.

Among other dryer types, a rotary dryer is the most common coal dryer used in the machinery industry. A coal rotary dryer works by rotating the damp coal in a large cylinder heated from outside. Hence, the coal can be dried uniformly. Notably, the specifications of a rotary dryer may vary according to the required production capacity.

Maintenance

A coal drier or dryer requires regular maintenance to ensure its smooth operation and long life. To begin with, there should be regular inspections of the whole machine. Manufacturers, maintenance professionals, or other relevant personnel should carefully examine the condition of the dryer to check if there are any signs of damage, loosening, and abnormal wear or noise.

Also, regular cleaning is important. Roting dryers benefit from the removal of residue and ash by cleaning the heating pipes and drying surfaces. Furthermore, pay attention to the surroundings of the dryer equipment. Coal driers shouldn't be placed in damp and stuffy environments. The surrounding air should be kept good by eliminating dust and water to prevent coal from dampness and ensure ventilation.

More importantly, lubricating and oiling the moving parts of the dryers helps reduce friction and ensure stable operation. Use the appropriate lubricant to comply with the equipment maintenance manual. Besides, coal drier dryers are often high-temperature and high-pressure equipment. Users should ensure that the sealing elements can bear heat and pressure. They should be replaced regularly if they are damaged to improve the sealing performance of the dryer.

Scenarios of coal drier/dryers

The main application of coal dryer/dryers is in the production and supply chain of coal. In some parts of the world, the weather is so humid that coal can't burn, which affects the industry. A coal drier can help change that. Mining industries, especially in those parts of the world, rely heavily on coal dryers to ensure that the coal is dried to the right point so it can burn. Other industries also use coal dryers.

Here are some industries that rely on coal dryers:

• Mining industry: The mining industry is the biggest user of coal dryers. In places where humidity is a big deal, coal needs to be dried, so it doesn't lose its burning capacity. Coal dryers help the industry produce coal that can be used for energy and other purposes.
• Cement industry: A coal dryer is used to dry raw materials that are used for cement. Those raw materials have to be dried to a point where they can be used to produce cement. Chalk, limestone, clay, and water are examples of those materials. A coal dryer also provides energy when coal is burned during the cement-making process.
• Fertilizer industry: Coal dryers are used in the fertilizer industry to reduce the moisture level of phosphorus, potassium, and nitrogen before they are mixed to form fertilizers. Coal also provides the energy needed to produce those fertilizers. Coal is used to burn plant matter and produce heat during the fertilizer production process.
• Steel and iron industry: Coal dryers in the steel industry are called coke ovens. Coal is put in those ovens without oxygen; high heat is applied to transform coal into coke fuel, which is used in the production of steel and iron. In the same way, coal dryers help reduce the moisture content of coal used to produce coke fuel.
• Power plants: In a coal power plant, coal dryers are used to ensure that the coal is properly dried so that combustion can occur during electricity generation. The moisture content has to be low to produce the right amount of heat to generate electricity.
• Sodium carbonate industry: Sodium carbonate is also called soda ash. It is produced through the Solvay process, in which ammonium chloride, carbon dioxide, water, and sodium chloride are reacted at a high temperature. A coal dryer is used to produce sodium carbonate. Coal provides energy in the form of heat during the process.
• Food industry: In the food industry, coal dryers can be used to dry food products such as grains, fruits, and vegetables. The coal is burned to produce heat, and that heat is used to dry the food products so they can have a longer shelf life and be consumed by people.
• Textile industry: The coal dryers in the textile industry are used to remove excess water from fabric after it has been woven and dyed. Coal is burned to produce heat, and that heat helps to dry the fabric quickly so it can be used in clothes making in no time.

How to Choose a Coal Drier

Before purchasing a coal dryer, buyers should know the following factors:

• Production Demand

  The drying capacity needed will primarily depend on operational production demand. It is essential to determine how much dried coal the business expects to produce within a specific timeframe. This helps evaluate the required drying capacity.

• Input Coal Characteristics

  Buyers should consider the qualities of the coal to be dried, such as moisture content, particle size, and composition. Different types of coal and their characteristics may require specific coal dryer designs.

• Drying Technology Options

  Buyers should know various drying technologies suitable for coal, such as rotary dryers, fluidized bed dryers, and belt dryers. Every technology has its advantages, disadvantages, and appropriate applications.

• Energy Efficiency

  Buyers should look for coal driers that have high energy efficiency. Such machines help reduce operating costs and environmental impact.

• Maintenance Requirements

  It is also essential to think about the maintenance needs of the coal dryer to be purchased. Buyers should select driers that have reliable designs and need simple maintenance procedures. This choice can ensure long-term operation and reduce downtime.

• Environmental Considerations

  Because the coal dryer can affect the environment, buyers should consider driers that have emission control systems. Also, choose those that comply with environmental regulations to minimize the impact on air quality.

• Cost Analysis

  Buyers should conduct a comprehensive cost analysis of the coal dryers under consideration. This analysis includes the initial investment, operating costs, maintenance costs, and potential returns from dried coal sales.

• Supplier Evaluation

  Because of the crucial role of the machine in the coal processing line, buyers should evaluate the suppliers of coal driers. They should select those sellers who have an excellent reputation and reliable product offering, good customer service, and prompt technical support.

FAQ

Q1: What is the future of coal dryer technology?

A1: The future of coal drying technologies maybe not be certain with the push towards renewable energies but advancements in mobile coal drier machineries and environmental sustainability will likely intersect with coal drying technologies.

Q2: How does a coal drier affect the power plant?

A2: A coal drier can have a significant impact on a power plant. Typically, a power plants efficiency is directly linked to the quality of coal being utilized. Therefore, a coal drier that improves the quality of coal can subsequently enhance the power plants efficiency. Furthermore, reducing the moisture content can allow a higher capacity to be processed, thus preventing capacity constraints.

Q3: How much energy does a coal dryer use?

A3: The energy usage of a coal dryer can range from 3,000 - 5,000 MJ per tonne of coal dried. This will vary according to the technology being utilized and the initial and target moisture content of the coal.