Rolling bed dryer

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Rolling bed dryers are used for efficiently processing large amounts of material that need their respective moisture levels reduced. Rolling bed dryers are most often used for drying wood chips and organic residues and are most often utilized in the biomass, waste/recycling, wood particle board, pellet, and biofuel industries. [1]

Contents

Rolling bed dryer Rolling Bed Dryer.jpg
Rolling bed dryer

General concept

The versatility of the rolling bed dryer is based on its simple idea of product circulation. The biomass processed through the rolling bed dryer can be not only efficiently dried but also has the option of being cleaned simultaneously. This provides for efficiency and conservation in energy which results in lower production costs. Biomass is being increasingly used as an alternative fuel source. [2] Providing for this demands innovative solutions. [3]

Applications

Process

Large bulks of biomass is permanently circulated and mixed by highly effective paddles. This basic idea combines the flow of large bulks of product good heat transfer with continuous movement of the product for even drying results. The drying air is supplied through a perforated plate under the moving bulk of product. Depending on the amount of ventilation., it is possible to separate fine materials such as dust, fibers, and sand from the bulk material collecting this separately alongside the ongoing drying process. This simultaneous cleaning occurs through the use of the material against itself to remove, separate, and collect fine materials such as fibers, sand and dust from the drying bulk material. Having this occur at the same time as the drying process saves not only time and energy, but also maintains better the caloric value of the residual biomass and reduces ash content.

After the drying process is completed the dried output is suitable for direct firing and pelletizing/briquetting as well as for more demanding processes such as gasification or torrefaction of biomass. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Gasification</span> Form of energy conversion

Gasification is a process that converts biomass- or fossil fuel-based carbonaceous materials into gases, including as the largest fractions: nitrogen (N2), carbon monoxide (CO), hydrogen (H2), and carbon dioxide (CO2). This is achieved by reacting the feedstock material at high temperatures (typically >700 °C), without combustion, via controlling the amount of oxygen and/or steam present in the reaction. The resulting gas mixture is called syngas (from synthesis gas) or producer gas and is itself a fuel due to the flammability of the H2 and CO of which the gas is largely composed. Power can be derived from the subsequent combustion of the resultant gas, and is considered to be a source of renewable energy if the gasified compounds were obtained from biomass feedstock.

<span class="mw-page-title-main">Medium-density fibreboard</span> Engineered wood product

Medium-density fibre (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibre, often in a defibrator, combining it with wax and a resin binder, and forming it into panels by applying high temperature and pressure. MDF is generally denser than plywood. It is made up of separated fibre but can be used as a building material similar in application to plywood. It is stronger and denser than particle board.

<span class="mw-page-title-main">Solid fuel</span>

Solid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fuels include wood, charcoal, peat, coal, hexamine fuel tablets, dry dung, wood pellets, corn, wheat, rye, and other grains. Solid fuels are extensively used in rocketry as solid propellants. Solid fuels have been used throughout human history to create fire and solid fuel is still in widespread use throughout the world in the present day.

<span class="mw-page-title-main">Wood fuel</span> Wood used as fuel for combustion

Wood fuel is a fuel such as firewood, charcoal, chips, sheets, pellets, and sawdust. The particular form used depends upon factors such as source, quantity, quality and application. In many areas, wood is the most easily available form of fuel, requiring no tools in the case of picking up dead wood, or few tools, although as in any industry, specialized tools, such as skidders and hydraulic wood splitters, have been developed to mechanize production. Sawmill waste and construction industry by-products also include various forms of lumber tailings.

<span class="mw-page-title-main">Briquette</span> Compressed block of biomass used for fueling a fire

A briquette is a compressed block of coal dust or other combustible biomass material used for fuel and kindling to start a fire. The term derives from the French word brique, meaning brick.

<span class="mw-page-title-main">PET bottle recycling</span> Recycling of bottles made of polyethylene terephthalate

Although PET is used in several applications,, as of 2022 only bottles are collected at a substantial scale. The main motivations have been either cost reduction or recycle content of retail goods. An increasing amount is recycled back into bottles, the rest goes into fibres, film, thermoformed packaging and strapping. After sorting, cleaning and grinding, 'bottle flake' is obtained, which is then processed by either:

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<span class="mw-page-title-main">Sawdust</span> Byproduct or waste product of woodworking operations (sawing, sanding, milling, etc.)

Sawdust is a by-product or waste product of woodworking operations such as sawing, sanding, milling and routing. It is composed of very small chips of wood. These operations can be performed by woodworking machinery, portable power tools or by use of hand tools. In some manufacturing industries it can be a significant fire hazard and source of occupational dust exposure.

<span class="mw-page-title-main">Pellet fuel</span> Solid fuel made from compressed organic material

Pellet fuels are a type of solid fuel made from compressed organic material. Pellets can be made from any one of five general categories of biomass: industrial waste and co-products, food waste, agricultural residues, energy crops, and untreated lumber. Wood pellets are the most common type of pellet fuel and are generally made from compacted sawdust and related industrial wastes from the milling of lumber, manufacture of wood products and furniture, and construction. Other industrial waste sources include empty fruit bunches, palm kernel shells, coconut shells, and tree tops and branches discarded during logging operations. So-called "black pellets" are made of biomass, refined to resemble hard coal and were developed to be used in existing coal-fired power plants. Pellets are categorized by their heating value, moisture and ash content, and dimensions. They can be used as fuels for power generation, commercial or residential heating, and cooking.

<span class="mw-page-title-main">Pellet stove</span> Stove that uses pellet fuel

A pellet stove is a stove that burns compressed wood or biomass pellets to create a source of heat for residential and sometimes industrial spaces. By steadily feeding fuel from a storage container (hopper) into a burn pot area, it produces a constant flame that requires little to no physical adjustments. Today's central heating systems operated with wood pellets as a renewable energy source can reach an efficiency factor of more than 90%.

<span class="mw-page-title-main">Sewage sludge treatment</span> Processes to manage and dispose of sludge during sewage treatment

Sewage sludge treatment describes the processes used to manage and dispose of sewage sludge produced during sewage treatment. Sludge treatment is focused on reducing sludge weight and volume to reduce transportation and disposal costs, and on reducing potential health risks of disposal options. Water removal is the primary means of weight and volume reduction, while pathogen destruction is frequently accomplished through heating during thermophilic digestion, composting, or incineration. The choice of a sludge treatment method depends on the volume of sludge generated, and comparison of treatment costs required for available disposal options. Air-drying and composting may be attractive to rural communities, while limited land availability may make aerobic digestion and mechanical dewatering preferable for cities, and economies of scale may encourage energy recovery alternatives in metropolitan areas.

<span class="mw-page-title-main">Cement kiln</span> High temperature rotating oven used for producing clinker

Cement kilns are used for the pyroprocessing stage of manufacture of portland and other types of hydraulic cement, in which calcium carbonate reacts with silica-bearing minerals to form a mixture of calcium silicates. Over a billion tonnes of cement are made per year, and cement kilns are the heart of this production process: their capacity usually defines the capacity of the cement plant. As the main energy-consuming and greenhouse-gas–emitting stage of cement manufacture, improvement of kiln efficiency has been the central concern of cement manufacturing technology. Emissions from cement kilns are a major source of greenhouse gas emissions, accounting for around 2.5% of non-natural carbon emissions worldwide.

<span class="mw-page-title-main">Biomass (energy)</span> Biological material used as a renewable energy source

Biomass, in the context of energy production, is matter from recently living organisms which is used for bioenergy production. Examples include wood, wood residues, energy crops, agricultural residues including straw, and organic waste from industry and households. Wood and wood residues is the largest biomass energy source today. Wood can be used as a fuel directly or processed into pellet fuel or other forms of fuels. Other plants can also be used as fuel, for instance maize, switchgrass, miscanthus and bamboo. The main waste feedstocks are wood waste, agricultural waste, municipal solid waste, and manufacturing waste. Upgrading raw biomass to higher grade fuels can be achieved by different methods, broadly classified as thermal, chemical, or biochemical.

<span class="mw-page-title-main">Biomass heating system</span>

Biomass heating systems generate heat from biomass. The systems may use direct combustion, gasification, combined heat and power (CHP), anaerobic digestion or aerobic digestion to produce heat. Biomass heating may be fully automated or semi-automated they may be pellet-fired, or they may be combined heat and power systems.

<span class="mw-page-title-main">Woodchips</span> Small pieces of wood made when shredding larger pieces of wood

Woodchips are small- to medium-sized pieces of wood formed by cutting or chipping larger pieces of wood such as trees, branches, logging residues, stumps, roots, and wood waste.

<span class="mw-page-title-main">Torrefaction</span>

Torrefaction of biomass, e.g., wood or grain, is a mild form of pyrolysis at temperatures typically between 200 and 320 °C. Torrefaction changes biomass properties to provide a better fuel quality for combustion and gasification applications. Torrefaction produces a relatively dry product, which reduces or eliminates its potential for organic decomposition. Torrefaction combined with densification creates an energy-dense fuel carrier of 20 to 21 GJ/ton lower heating value (LHV). Torrefaction makes the material undergo Maillard reactions. Torrefied biomass can be used as an energy carrier or as a feedstock used in the production of bio-based fuels and chemicals.

The Allgaier Group is a systems supplier for the international automotive industry, including production of body panel dies as well as forming technology involving the production of pressed components and ready-to-fit components. The second pillar of the Allgaier Group is machinery and apparatus engineering for process technology. Allgaier produces and deliver systems worldwide for screening, drying/cooling, washing and sorting to companies in the bulk goods processing industry. The company currently has about 1880 people, a good two thirds of whom work at the headquarters in Uhingen, Germany. The Allgaier Group includes production and sales companies in Germany, Spain, Sweden and other countries, as well as agencies in all major industrial countries of the world.

<span class="mw-page-title-main">Industrial dryer</span>

Industrial dryers are used to efficiently process large quantities of bulk materials that need reduced moisture levels. Depending on the amount and the makeup of material needing to be dried, industrial dryers come in many different models constructed specifically for the type and quantity of material to be processed. The most common types of industrial dryers are fluidized bed dryers, rotary dryers, rolling bed dryers, conduction dryers, convection dryers, pharmaceutical dryers, suspension/paste dryers, toroidal bed or TORBED dryers and dispersion dryers. Various factors are considered in determining the correct type of dryer for any given application, including the material to be dried, drying process requirements, production requirements, final product quality requirements and available facility space.

Gyratory equipment, used in mechanical screening and sieving is based on a circular motion of the machine. Unlike other methods, gyratory screen operates in a gentler manner and is more suited to handle fragile things, enabling it to produce finer products. This method is applicable for both wet and dry screening.

Agglomerated food powder is a unit operation during which native particles are assembled to form bigger agglomerates, in which the original particle can still be distinguished. Agglomeration can be achieved through processes that use liquid as a binder or methods that do not involve any binder.

References

  1. http://www.almoprocess.com/content/rolling-bed-dryer
  2. Bin Bujang, Ahmad Safuan (2011). Properties and bulk drying of biomass (MS thesis). Iowa State University. doi: 10.31274/etd-180810-1346 . hdl:20.500.12876/26302.
  3. http://gdi.ce.cmu.edu/gd/Research/biomass.pdf [ bare URL PDF ]
  4. "Archived copy" (PDF). Archived from the original (PDF) on 2014-11-30. Retrieved 2013-06-11.{{cite web}}: CS1 maint: archived copy as title (link)