Lumpy inorganic sludge drying, Low-temperature drying of lumpy inorganic sludge, which is difficult to dry / Test cases / Sludge dryer, Reduction of industrial waste

Summary

KENKI DRYER is a highly efficient, patented drying system designed for materials like sludge from wastewater treatment plants. It prevents clogging during drying, even for lumpy and sticky materials, through a unique mechanism that reduces surface area for better moisture removal. The dryer operates at low temperatures, preserving the material’s composition for recycling and upcycling. It uses steam efficiently, minimizing energy consumption and carbon emissions, and can run continuously, enabling 24-hour, unmanned operation.

Additionally, the KENKI DRYER contributes to environmental protection and decarbonization by reducing waste volume, transport needs, and CO2 emissions. With 11 patents in 8 countries, the KENKI DRYER is known for its ability to handle difficult-to-dry materials, its durability, ease of maintenance, and low operating costs, making it a popular choice for industries focused on drying and recycling organic and inorganic materials.

In the drying process of KENKI DRYER, lumpy sludge and other dried materials are crushed to a certain extent inside the dryer to reduce their surface area, which allows sufficient drying to occur inside the dried materials. Even lumpy dried materials may not be discharged because of clogging inside the dryer due to strong adhesion during drying, but KENKI DRYER’s unique, world-patented mechanism prevents clogging inside the dryer and enables smooth drying.

Sludge discharged from wastewater treatment plants tends to become lumpy during the drying process due to the coagulant used in wastewater treatment. In the drying process of the KENKI DRYER, even if the dried material becomes lumpy, it is crushed to a certain extent in the dryer to reduce its surface area, thereby ensuring that the dried material is dried to a sufficient degree inside the dryer. This allows drying to the inside of the dried material.

Even difficult-to-dry, highly adhesive materials can be dried easily and smoothly with the KENKI DRYER. For example, dewatered sludge discharged from sewage treatment plants is difficult to dry due to its strong adhesive property. KENKI DRYER has a world patented unique mechanism that can dry even highly adhesive and sticky dewatered sludge without clogging the dryer.

Japan is almost 100% dependent on imports for its mineral resources. In the future, precious metals and rare metals in particular will continue to be important resources, and securing these resources is essential to maintaining and strengthening international competitiveness. One of the measures to secure mineral resources is the reuse and recycling of minerals contained in sludge, which will contribute to environmental protection and reduce greenhouse gas emissions. Phosphorus, which is currently imported from China, is also an indispensable mineral. Therefore, the extraction of phosphorus from sewage sludge is promoted as a national project.
The reuse and recycling of sludge from wastewater treatment plants is becoming increasingly important for environmental protection, decarbonization, and securing resources that are currently dependent on imports.

KENKI DRYER dries sludge discharged from wastewater treatment plants at low temperatures, which makes it possible to recycle and upcycle the sludge with little change in composition after drying. It can be fully utilized as recycled and upcycled products.

KENKI DRYER, with 11 patents in 8 countries, is an indirect steam dryer, but it is a completely unique product, different in structure from other similar indirect steam dryers. The KENKI DEYER uses steam as a heat source, but its high drying heat efficiency means that less steam is used. The use of excess steam is not costly in terms of fuel costs, and the dryer does not emit carbon dioxide during the drying process, allowing for decarbonized drying. Alternatively, by installing an electric boiler, no greenhouse gases or CO2 emissions are generated during drying.
The KENKI DRYER is a continuous dryer, not a batch dryer that stores and dries materials to be dried. Therefore, operation is simple and unmanned operation is possible 24 hours a day.

Drying sludge to reduce its weight and the amount of waste materials can contribute to environmental protection and decarbonization by reducing the cost of industrial waste, which is increasing due to the recent trucking problem in 2024, and by reducing the number of trucks transporting waste materials, thereby reducing carbon dioxide emissions.

If you have any questions or concerns, please let us know. We will be happy to suggest the best dryer for your company’s needs.
Our dryer “KENKI DRYER” has obtained 11 patents in 8 countries and is good at drying sticky materials that others cannot dry, has no problems after installation, is easy to maintain and has low operating cost. The KENKI DRYER has been well received by companies that have installed it because of its uniform drying, improved productivity requiring less manpower, high performance, and durability.

KENKI DRYER can dry sticky and adhesive materials that others cannot dry. KENKI DRYER is a breakthrough drying device with a total of 11 patents (2 in Japan and 9 in 7 overseas countries). Please consider KENKI DRYER for your high moisture organic waste dryer, sludge dryer, slurry dryer, methane fermentation digestate dryer, and waste upcycling or recycling dryer.

KENKI DRYER has been granted 11 patents in 8 countries (Japan, Taiwan, USA, France, Germany, UK, Switzerland, Canada).

There are several compelling reasons to choose KENKI DRYER for inorganic sludge drying, as outlined below:

1. Unique Drying Mechanism:
   • KENKI DRYER features a patented, unique mechanism that allows for the efficient drying of highly sticky and adhesive materials, including inorganic sludge. This mechanism prevents clogging and ensures smooth and uniform drying.
2. Low-Temperature Drying:
   • The dryer operates at low temperatures, which minimizes compositional changes in the dried material. This is particularly beneficial for inorganic sludge, as it preserves the material’s original properties and makes it suitable for recycling and upcycling.
3. Continuous Operation:
   • KENKI DRYER enables 24-hour continuous operation without the need for manual intervention, making it highly efficient and reducing labor costs.
4. High Efficiency and Cost Savings:
   • The dryer uses low-pressure steam as the heat source, which is at least three times more efficient than hot-air drying. This results in lower fuel costs and reduced environmental impact due to lower carbon dioxide emissions.
5. Easy Maintenance:
   • The dryer has a simple structure with fewer replacement parts, making maintenance easier and reducing downtime. This simplicity also contributes to the longevity of the equipment.
6. Handling of Sticky Materials:
   • KENKI DRYER is specifically designed to handle materials that are difficult to dry, such as those with high moisture content and strong adhesion. The dryer’s unique blades and agitation system ensure that these materials are dried without clogging the equipment.
7. Environmental Benefits:
   • By efficiently drying inorganic sludge, KENKI DRYER contributes to environmental protection and resource conservation. It helps in recycling and reusing minerals contained in the sludge, which is crucial for countries dependent on mineral imports.

These features make KENKI DRYER an ideal choice for drying inorganic sludge, offering a combination of efficiency, cost-effectiveness, and environmental sustainability.

Inorganic refers to substances that are not derived from living organisms and typically do not contain carbon-hydrogen bonds. This term is used in chemistry to describe a broad range of materials and compounds, including minerals, metals, salts, and certain gases. Inorganic chemistry is the branch of chemistry that deals with the properties and behavior of inorganic compounds.

Key characteristics of inorganic compounds include:

1. Composition: Often composed of elements other than carbon, though some carbon-containing compounds like carbonates and cyanides are considered inorganic.
2. Structure: Typically have simple structures, though some, like silicates, can be quite complex.
3. Properties: Can have a wide range of properties, including being solids, liquids, or gases at room temperature; having high melting and boiling points; and being good conductors of electricity (in the case of metals).

Inorganic compounds are found in various forms and are used in numerous applications, from construction materials (like cement and glass) to catalysts and semiconductors.

Source：ChatGPT

Sludge is a semi-solid slurry that can be produced from a range of industrial processes, from water treatment, wastewater treatment or on-site sanitation systems. It can be produced as a settled suspension obtained from conventional drinking water treatment, as sewage sludge from wastewater treatment processes or as fecal sludge from pit latrines and septic tanks. The term is also sometimes used as a generic term for solids separated from suspension in a liquid; this soupy material usually contains significant quantities of interstitial water (between the solid particles). Sludge can consist of a variety of particles, such as animal manure.

Source：Wiki Sludge

Inorganic sludge refers to the semi-solid material that results from the treatment of wastewater, industrial processes, or other activities that involve the removal of inorganic contaminants. This type of sludge is primarily composed of non-organic materials such as metals, metal oxides, minerals, and other inorganic compounds. Inorganic sludge can originate from various sources, including:

1. Industrial Processes: Industries such as mining, metal processing, and chemical manufacturing often produce inorganic sludge as a byproduct of their operations.
2. Water and Wastewater Treatment: During the treatment of water and wastewater, inorganic particles are removed through processes like coagulation, flocculation, sedimentation, and filtration, resulting in the formation of inorganic sludge.
3. Construction and Demolition: Activities in construction and demolition can produce inorganic sludge, particularly when dealing with concrete, bricks, and other building materials.

Key characteristics and considerations of inorganic sludge include:

• Composition: Rich in metals, metal oxides, silica, and other inorganic substances.
• Disposal and Management: Inorganic sludge often requires special handling and disposal due to the presence of hazardous materials such as heavy metals. It may be treated, stabilized, and disposed of in landfills or used in certain construction applications if deemed safe.
• Environmental Impact: Improper management of inorganic sludge can lead to environmental contamination, particularly if it contains toxic substances. Therefore, it is subject to strict regulatory controls to ensure safe handling and disposal.

The management of inorganic sludge is crucial for minimizing its environmental impact and ensuring compliance with environmental regulations.

Source：ChatGPT

Inorganic sludge and organic sludge are two main types of sludge produced in wastewater treatment processes. They differ significantly in their composition and the methods used to treat them.

Inorganic Sludge

• Composition: Primarily consists of inorganic materials like sand, grit, metals, and minerals.
• Sources: Often originates from industrial wastewater, construction sites, and stormwater runoff.
• Treatment: Typically involves physical methods like sedimentation, filtration, and centrifugation.
• Disposal: Often disposed of in landfills or used for construction materials.

Organic Sludge

• Composition: Primarily consists of organic matter, including bacteria, viruses, and biodegradable substances.
• Sources: Primarily comes from domestic wastewater, food processing plants, and agricultural runoff.
• Treatment: Often involves biological processes like aerobic or anaerobic digestion.
• Disposal: Can be composted, used for biofuel production, or land-applied for agricultural purposes.

Key Differences:

Feature	Inorganic Sludge	Organic Sludge
Composition	Primarily inorganic materials	Primarily organic matter
Sources	Industrial wastewater, construction sites	Domestic wastewater, food processing
Treatment	Physical methods	Biological processes
Disposal	Landfills, construction materials	Composting, biofuel, land application

Understanding the differences between inorganic and organic sludge is crucial for proper wastewater treatment and disposal. By tailoring treatment methods to the specific type of sludge, we can ensure efficient and environmentally responsible management of this by-product.

Source：Gemini

There are several key reasons why sludge, often produced as a byproduct of wastewater treatment, needs to be dried:

• Volume Reduction: Sludge typically contains a high percentage of water. Drying significantly reduces this water content, leading to a much smaller volume. This makes transporting and storing the sludge far more manageable and cost-effective.

• Disposal and Further Treatment: Dried sludge can be easier and safer to dispose of compared to wet sludge. For instance, dried sludge can meet specific regulations for incineration or landfilling. In some cases, drying can also be a precursor to other treatment methods.

• Resource Recovery: When properly dried, sludge can be repurposed for beneficial uses. This could involve using it as a soil conditioner or even converting it into a fuel source.

• Pathogen Reduction: Drying can help reduce the number of harmful pathogens present in the sludge. This makes it a safer material to handle and potentially reuse.

• Odor Control: Wet sludge can be quite odorous. Drying helps to stabilize the sludge and significantly reduces unpleasant smells.

Source：Gemini

Sludge drying is a challenging process due to several factors that complicate its efficient and effective execution. Here are the main reasons why sludge drying can be difficult:

1. High Moisture Content:

   • Initial Moisture Levels: Sludge typically has a very high initial moisture content (up to 98% water), which requires significant energy to reduce.
   • Bound Water: Some water in sludge is chemically bound to particles, making it harder to remove through conventional drying methods.

2. Energy Requirements:

   • High Energy Consumption: Drying sludge to a low moisture content requires substantial energy, especially for thermal drying processes.
   • Cost: The energy costs associated with sludge drying can be high, impacting the overall economics of the wastewater treatment process.

3. Complex Composition:

   • Variable Composition: Sludge composition can vary widely depending on the source and type of wastewater being treated. This variability can affect drying efficiency and the selection of appropriate drying technologies.
   • Presence of Inorganic and Organic Materials: The mixture of organic and inorganic materials in sludge can complicate the drying process.

4. Handling and Processing:

   • Sticky and Viscous Nature: Wet sludge can be sticky and viscous, making it difficult to handle, transport, and process in drying equipment.
   • Clogging and Fouling: Sludge can clog or foul drying equipment, requiring frequent maintenance and cleaning.

5. Environmental and Health Concerns:

   • Odor Emissions: Drying sludge can produce unpleasant odors, which need to be managed through odor control systems.
   • Air Pollution: Thermal drying processes can release volatile organic compounds (VOCs) and other air pollutants, necessitating air pollution control measures.

6. Equipment and Technology:

   • Specialized Equipment: Sludge drying often requires specialized equipment, such as belt dryers, drum dryers, or fluidized bed dryers, which can be expensive to purchase and maintain.
   • Operational Complexity: Managing the drying process requires skilled operators to ensure optimal performance and to address any issues that arise during operation.

7. Disposal of By-products:

   • Residual Waste: Even after drying, there is still a need to dispose of the dried sludge or its ash if incinerated, which can involve additional costs and regulatory compliance.

8. Regulatory Compliance:

   • Stringent Regulations: There are often strict regulations governing the drying and disposal of sludge, particularly concerning emissions and pathogen reduction, which can add complexity to the process.

In summary, sludge drying is difficult due to high moisture content, significant energy requirements, complex sludge composition, handling challenges, environmental and health concerns, specialized equipment needs, and stringent regulatory requirements. These factors make sludge drying a technically and economically challenging process in wastewater treatment.

Source：ChatGPT

• Material to be dry: Inorganic sludge, which is difficult to dry
• Purpose of drying: Reducing industrial waste cost and amount
• Moisture content: 68.2％W.B. before drying, 13.8％W.B. after drying
• Requirements for dryer: To prevent clogging inside the dryer caused by the stickiness and adhesiveness. Automated continuous operation with no operator attended.
  Machine cost can be recovered in short term.
• Test result: OK

Sludge drying

Competitive comparison

One of the International Patented Technology that KENKI DRYER has is a self-cleaning structure called Steam Heated Twin Screw technology (SHTS technology). No matter how materials are sticky, adhesive and viscous is, they can be dried without clogging inside of the dryer because of this unique structure that no other products has.
For example, even materials stuck to the blades of one screw, blades of the other screw in the dryer’s body forcibly peels the materials off as they rotate. Since the blades rotate by peeling the material off each other, any sticky, adhesive and viscous material does not adhere to the blade, and the blades continue rotating, peeling, agitating and heating material without stopping while they carries material further. Also, since surface of blades are always renewed and kept clean, heat near the blades is not blocked and it is conducted directly into the materials.

Self-cleaning screw

KENKI DRYER has three main characteristics. They are 1) Any materials can be dried as expected including sticky, adhesive and viscous materials and raw material slurry that no other company can deal with, 2) dried material can by recycled or utilized as raw materials because of its low-temperature drying method, and 3) there is no need to assign operator since its continuous operating system makes 24 hours unattended operation possible.

Products

The unique and original drying mechanism of KENKI DRYER is also International Patented Technology. Because 4 drying mechanisms which are crashing drying, agitation drying, circulation drying and indirect drying work simultaneously and add heat to material being dried repeatedly and continuously, inner part of the material is dried thoroughly and quality of discharged material after drying is stable. This series of drying mechanisms prevents agglomeration which causes insufficient drying from feeding process of the material into the dryer until discharging process after drying completed. Various ingenuities to conduct heat surely into inner part of the materials are exercised and stable heating and drying are proceeded continuously.

Methods

Even KENKI DRYER uses only saturated steam as its heat source, it is outstanding in safety and hygiene point of view with its unique drying mechanism based on combined use of conductive heat transfer method and heated air method. Since steam is a stable heat source, quality of discharged material after drying is also stable and equable. Maximum allowed steam pressure is 0.7Mpa and adjustment of steam pressure, adjustment of drying temperature in other words, can be easily done. Saturated steam is commonly used in many factories so that it can be said as a familiar and handy heat source. In comparison with drying methods using burner or hot blasts, saturated steam method is an indirect drying applying heat exchange via pipes that steam is passing through, therefore, it hardly burns the materials and is outstanding in safety and hygiene point of view.

Heat source, Steam