Gravimetric coal feeder

Types of Gravimetric Coal Feeders

A coal feeder's job is to supply coal at a constant rate to a furnace. Coal is fed to the furnace or boiler using a coal feeder at a predetermined rate to keep the temperature and pressure of the system constant. The two primary functions of a coal feeder are to ensure the constant flow of coal to the furnace/boiler and to control the calorific value of the >”ash”” in the end by varying the constituents of the coal being used.

Functions of coal feeders

• By varying the quantity of coal being fed to the furnace/boiler, the temperature and pressure of the system can be controlled.
• Also known as the chemical energy change, it is possible to regulate the constituents of the coal being utilized, which in turn controls the calorific value of the ashes produced.

Types of gravimetric coal feeders

The two main types of coal feeders are typically as follows:

• Ash dump feeder: An ash dump feeder is a device that conveys ash materials collected from a boiler or industrial process into an ash dump site or storage area. It ensures the safe and efficient disposal of ash waste to prevent environmental contamination and comply with regulatory guidelines.
• Ash conveyor feeder: An ash conveyor feeder is a mechanical system that transports ash generated from the combustion of coal or other fuels in boilers or furnaces to an appropriate disposal location. The primary function of an ash conveyor feeder is to remove ash waste from the combustion process and convey it for further processing, storage, or disposal.
• Ash sluice feeder: An ash sluice feeder is a crucial component of ash handling systems used in power plants and industrial facilities to manage the disposal of ash generated during the combustion of coal or biomass. Its primary function is to convey the hot or cold ash from the combustion process into a designated ash storage, processing, or disposal area.
• Bin feeder: A bin feeder in material handling refers to a device used to control the flow rate of bulk materials from storage bins or hoppers onto conveyers or other processing equipment. Bin feeders are designed to regulate the discharge of materials such asAggregates,Coal,Clinker,Grain andPowdered cement, among others, ensuring a consistent and controlled feed to downstream processes.
• An industrial feeder: An industrial feeder is a device used to regulate and control the uniform feeding of bulk materials into processing equipment or production lines in various industrial settings. These feeders are essential in industries such as mining, agriculture, food processing, pharmaceuticals, and manufacturing, where precise and consistent material input is required for subsequent operations.
• A volumetric feeder: A volumetric feeder is a device used to measure and dispense materials based on volume rather than weight actively. These feeders are commonly used in various industries, including food processing, pharmaceuticals, chemicals, and mining, to feed bulk materials, liquids, or powders into processing equipment, containers, or production lines.

Specifications and maintenance of a gravimetric coal feeder

The main specifications of a gravimetric coal feeder are listed in the following table for reference. However, they might vary depending on the actual models.

• Carrying Capacity

  The feeder's holding capacity states the max amount of coal it can carry. For instance, a large feeder may carry up to 4,000 kg of coal.

• Conveyor Speed

  The rate of the conveyor belt is its feeder speed. It shows how fast coal can be transported. For example, a feeder belt might move at 0.25 m/s.

• Power Consumption

  This helps to state how much energy it uses to function. An electrically-operated feeder may use 2 kWh of power daily.

• Dimensions

  The overall dimensions and weight of the feeder. For instance, a large feeder can measure 3 long, 1.5 wide, and 2 meters tall. It can weigh about 1,200 kg.

• Operating Temperature

  The feed can work in different temperature ranges. For example, it can function between -10° and +50° C.

• Moisture Tolerance

  The tolerance level of moisture in coal before feeder operation, It can work with coal moisture levels up to 10%.

• Control System

  It is the type of control used to operate the coal feeder. For example, it can be a PLC system with Software for Coal Feeding controls.

• Weighing Mechanism

  It could be a load cell-based system, a belt scale, or a volumetric batching method.

Maintenance

It is crucial to follow some maintenance tips for long-lasting gravimetric feeder operation. The users should regularly clean the coal feeder to prevent coal dust from building up. It can help to reduce the risk of blockages and fire hazards. They should lubricate any moving parts, such as motors, belts, and drives. Doing this will ensure smooth and noiseless operation.

Users should check the feeder regularly for any signs of wear or damage. These may include belt misalignment, loose fasteners, and cracked or damaged load cells. Prompt repair can help to avoid larger and costly repairs later on. Also, they should ensure that coal of the correct size is fed into the system to prevent overloading it.

Finally, regularly calibrating the feeder and weighing mechanism is essential. It will help to maintain accurate coal measurement and provide a consistent coal supply to the furnace or boiler. In case of any doubts, users should always refer to the manufacturer's manual for the recommended coal feeder maintenance tasks and schedules.

Usage scenarios of gravimetric coal feeders

The feeders have varied applications across industries that use coal as raw material or fuel. Here are some common usage scenarios of coal feeders.

• Power plants

  Coal feeders are used in power plants to supply and regulate coal fuel to boilers and combustion chambers. The feeder supplies a consistent coal amount, helping maintain constant power output while ensuring efficient coal utilization.

• Cement plants

  Cement plants use coal as the primary fuel for kilns to produce cement. Coal gravimetric feeders are used to supply a consistent amount of coal to the cement plant's furnaces or boilers. The consistent coal supply helps maintain stable cement production processes.

• Steel mills

  Steel production processes use coal as a reducing agent and energy source. Coal feeders supply coal to blast furnaces, sintering machines, and other steel production equipment. The feeders help the steel mills maintain stable production and efficient coal utilization.

• Thermal power generation

  Coal gravimetric feeders are commonly used in thermal power generation systems, such as coal-fired power plants. They are used to supply and control the coal feed rate to boilers or combustion chambers as coal fuel. The proper functioning of the feeders contributes to stable power generation, boiler efficiency, and environmental compliance.

• Industrial boilers

  Many industries use coal as an energy source. Industries such as chemical, textile, food processing, and manufacturing use coal gravimetric feeders to provide a stable coal supply for their industrial boilers. The boilers use coal as a fuel for steam generation or heating, and the feeders help the boilers maintain stable operation.

• Carbon product facilities

  Some facilities produce carbon products, such as activated carbon and carbon black, use coal as a raw material. Coal feeders can supply coal to the reaction or processing equipment, ensuring stable feed and product quality. This maintains continuous production processes.

How to Choose a Gravimetric Coal Feeder

While selecting a gravimetric feeder for coal, there are certain things that buyers need to consider. This will help them to choose the best feeders for their industrial applications.

• Usage Requirements:

  The primary considerations are the demanded quantities and the sizes of different coals. Also, note the preferred feeding rates and accuracies. Conversely, specific applications like firing boilers may require distinct feeder features.

• Feeding Technologies:

  Buyers need to compare different feeding methods and choose suitable feeders based on coal's physical traits and usage needs. For example, they can opt for screw feeders if they desire a continuous coal supply or loss-in-weight feeders for high precision.

• Control Systems:

  Buyers should also evaluate the feeder's control system and ensure it can integrate well with their plant automation setup. Also, the feeder should possess user-friendly interfaces for straightforward operation and monitoring.

• Maintenance Needs:

  Consider the feeder's maintenance requirements and select those with accessible components, robust construction, and proven reliability. Also, check whether the feeder manufacturer offers detailed maintenance manuals and global support services.

• Product Size and Weight:

  Now, based on the site constraints and coal transportation needs, decide on the appropriate sizes and weights of the feeders.

• Safety Features:

  Buyers should also consider the feeder's safety features. This may include overload protection mechanisms and emergency stop buttons, among others. Ensure the feeders comply with relevant safety regulations and standards.

• Budget:

  While it is essential to set aside a budget, consider the total cost of ownership, performance, and feeding precision of the proposed coal feeders. Select those that provide excellent value for the business in terms of long-term operational efficiency.

Gravimetric Coal Feeder Q&A

Q1: Does a gravimetric coal feeder use constant weight or hourly weight for measurement?

A1: The feeder measures coal by its hourly weight, but it regulates the coal that enters the furnace by its constant weight.

Q2: What are the advantages of gravimetric feeders?

A2: The main advantages of gravimetric feeders are achieving better accuracy and greater control by measuring the actual weight of the material being fed. While volumetric feeders can be more straightforward and less expensive, gravimetric feeders offer higher precision.

Q3: What is the difference between volumetric and gravimetric feeders?

A3: Volumetric feeders determine the volume of the material being fed, while gravimetric feeders measure it by weight. Gravimetric feeders have higher accuracy than gravimetric feeders.

Q4: What are the different types of gravimetric feeders?

A4: The main types are belt feeders, screw feeders and loss-in-weight feeders. The most common are belt and loss-in-weight feeders, which weigh the load on the belt continuously. Other feeders measure the weight of the feeder refilling, like in a batch process.