Inorganic sludge drying, Low-temperature drying of strongly sticky and adhesive inorganic sludge / Test cases / Sludge dryer, Reduction of industrial waste

Summary

Here is a summarized version of the key points regarding the KENKI DRYER for drying inorganic sludge and other sticky, adhesive materials:

Unique Drying Mechanism
KENKI DRYER features a patented, unique mechanism that prevents clogging and ensures smooth and uniform drying of highly sticky and adhesive materials, including inorganic sludge.

Low-Temperature Drying
The dryer operates at low temperatures, minimizing compositional changes in the dried material. This makes it suitable for recycling and upcycling, as the material’s original properties are preserved.

Handling Lumpy and Sticky Materials
Even if the sludge becomes lumpy during the drying process due to coagulants or strong adhesion, KENKI DRYER crushes the material to reduce its surface area, ensuring thorough drying of the inside of the material.

Continuous Operation and Efficiency
KENKI DRYER allows for 24-hour continuous, unmanned operation. It uses steam efficiently, reducing fuel costs and minimizing wear on parts, which makes maintenance easy and inexpensive.

Environmental Benefits
The dryer contributes to environmental protection and decarbonization by reducing carbon dioxide emissions. It helps in recycling and reusing minerals contained in the sludge, which is crucial for countries dependent on mineral imports.

Versatility and Applications
KENKI DRYER is versatile and can be used for drying sludge from wastewater treatment plants, organic waste, methane fermentation digested liquid, and various other waste materials. It can convert materials into biochar, bio-coke, or other recyclable products.

Patents and Recognition
KENKI DRYER has been granted a total of 11 patents in 8 countries (Japan, Taiwan, USA, France, Germany, UK, Switzerland, Canada), highlighting its innovative technology.

Operational Advantages
The dryer uses steam as a heat source, which reduces fuel costs and does not emit carbon dioxide during the drying process. It also allows for the option of using an electric boiler to eliminate greenhouse gas emissions. The slow rotation speed of the blades (5 rpm or less) minimizes wear and maintenance costs.

Contribution to Resource Conservation
By drying and recycling sludge, KENKI DRYER helps in securing mineral resources, such as phosphorus, which is essential and currently imported. This process supports environmental protection.

Even if the drying object has a strong sticking adhesive quality and is difficult to dry, KENKI DRYER can easily and smoothly dry it. For example, dehydrated sludge discharged from wastewater treatment plants with a strong sticking adhesive quality is difficult to dry. Depending on the type of dryer, sludge can become clogged inside the dryer during the drying process and may not be able to be discharged. With KENKI DRYER, however, even sticky or adhesive materials that would normally cause clogging can be dried easily without clogging inside the dryer. KENKI DRYER is an innovative drying device with unique technology that has been granted a total of 11 patents, including 2 in Japan and 9 in 7 countries overseas.

After dehydration, many of the dried sludge objects are found to be in a lumpy form, regardless of whether they are inorganic or organic. In  KENKI DRYER, the dried objects, such as lumpy sludge, are crushed to a certain extent inside the dryer, and by reducing the surface area, the drying process is able to thoroughly dry even the inside of the dried objects. Even with lumpy objects to be dried, there are cases where the sticking adhesive quality is so strong that they get stuck inside the dryer and cannot be discharged, but KENKI DRYER has a unique mechanism that is patented worldwide, so it can dry objects smoothly without getting stuck inside the machine.

In addition, the sludge discharged from wastewater treatment plants tends to clump together during the drying process due to the effect of the flocculants used during wastewater treatment. When the material being dried forms lumps, the heat does not spread sufficiently throughout the material and the inside of the material does not heat up, so only the surface dries and the inside does not heat up and dry. Even if the material being dried forms lumps, KENKI DRYER can dry the inside of the material sufficiently by crushing and reducing the size of the material to a certain extent inside the dryer and reducing the surface area.

By drying sludge discharged from wastewater treatment plants at low temperatures, it is possible to utilize it as compost, soil conditioner, fuel, etc. as upcycling, with minimal changes in composition after drying. KENKI DRYER is an indirect drying system that uses steam as a heat source at low temperatures, so after drying, there are minimal changes in the composition of the dried material, making it fully recyclable and suitable for upcycling.

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 produced during drying.
The dryer’s blades rotate at a very slow speed of 5 rpm or less, which means that wear on parts is minimal and maintenance is easy and inexpensive. KENKI DRYER is a continuous dryer, not a batch dryer that stores materials to be dried. Therefore, operation is simple and unmanned operation is possible 24 hours a day.

Drying sludge to reduce the weight and volume of waste products can contribute to environmental protection and decarbonization by reducing the cost of industrial waste, which is rising due to the recent trucking problem in 2024, and by reducing the number of trucks used to transport waste, thereby reducing carbon dioxide emissions.

Japan is almost 100% dependent on imports for its mineral resources. In particular, precious and rare metals are important resources that must be secured in order to maintain and strengthen international competitiveness. One measure for securing mineral resources is to reuse and recycle the minerals contained in sewage sludge, which is important for environmental protection and leads to a reduction in greenhouse gases. Phosphorus, which is currently imported and is also essential, is another mineral that we cannot do without. For this reason, the extraction of phosphorus from sewage sludge is being promoted as a national project.
The upcycling and recycling of sludge, which is always discharged from wastewater treatment plants, is emphasized for environmental protection, decarbonization and securing resources that are dependent on imports and the demand for which is only increasing.

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 received 11 patents in 8 countries and is particularly effective at drying sticky materials that others cannot handle. It has no installation problems, is easy to maintain, and has low operating costs. The KENKI DRYER has been well received by companies that have installed it due to its uniform drying, improved productivity with less manpower, high performance and durability.

KENKI DRYER, which can dry sticky and adhesive materials that others cannot, is a breakthrough dryer with a total of 11 patents (2 in Japan and 9 in 7 foreign countries) and proprietary technology. Please consider KENKI DRYER for your high moisture organic waste dryer, sludge dryer, slurry dryer, methane fermentation digested liquid dryer, waste upcycling and recycling dryer.
KENKI DRYER has been granted 11 patents in 8 countries (Japan, Taiwan, USA, France, Germany, UK, Switzerland, Canada).

KENKI DRYER is a highly efficient and innovative drying system designed specifically for inorganic sludge.

Patented Technology:
KENKI DRYER employs a unique, patented mechanism that ensures smooth and uniform drying, even for sticky and lumpy sludge. This prevents clogging and ensures that the entire sludge mass is dried thoroughly.

Low-Temperature Drying:
The dryer operates at low temperatures, preserving the material’s composition and making it suitable for recycling and upcycling. This is particularly important for inorganic sludge, which often contains valuable materials that can be recovered.

High Efficiency:
KENKI DRYER is highly energy efficient, using steam as the heat source to minimize fuel costs. This not only reduces operating expenses but also contributes to environmental sustainability.

Continuous Operation:
The dryer is designed for continuous operation, allowing for 24-hour, unattended drying. This maximizes productivity and reduces downtime.

Reduced Environmental Impact:
By reducing the volume of wet sludge, KENKI DRYER helps to minimize transportation costs and associated carbon emissions. Additionally, the dryer’s efficient use of energy contributes to decarbonization efforts.

Easy Maintenance:
The dryer is designed for easy maintenance, with low wear on parts and minimal downtime for servicing.

Versatility: KENKI DRYER is not only suitable for inorganic sludge but can also be used to dry various organic wastes, making it a versatile solution for a range of applications.

In summary, KENKI DRYER offers a combination of high efficiency, environmental friendliness, and versatility, making it an excellent choice for inorganic sludge drying.

Choosing KENKI DRYER for metal sludge drying offers several significant advantages, particularly in the context of urban mining and recycling of precious and minor metals. Here are some key reasons:

Unique Drying Mechanism
KENKI DRYER features a patented, unique mechanism that prevents clogging during the drying process. This is crucial for metal sludge, which can be highly sticky and adhesive. The dryer’s design ensures smooth and uniform drying without the issues commonly encountered with conventional dryers.

Low-Temperature Drying
The dryer operates at low temperatures, which minimizes changes in the composition of the dried material. This preservation is essential for maintaining the value and recyclability of the metals contained in the sludge. Low-temperature drying also helps in preserving the original properties of the materials, making them easier to recycle and upcycle.

Continuous and Unattended Operation
KENKI DRYER can operate continuously for 24 hours without the need for manual intervention. This unattended operation enhances productivity and reduces labor costs, making it highly efficient for industrial use.

Efficient and Stable Drying
The dryer uses saturated steam as a heat source and combines both conductive heat transfer and heated air methods for heat exchange. This unique system ensures uniform and stable drying of the material, even for highly adherent and sticky sludges.

Environmental and Economic Benefits
Drying metal sludge with the KENKI DRYER contributes to environmental protection by reducing waste volume and industrial waste costs. It also supports decarbonization efforts by minimizing energy consumption and greenhouse gas emissions.

Long Component Life and Low-Cost Operation
The low-temperature drying process of KENKI DRYER extends the life of its components and reduces maintenance costs. This, combined with low operating costs, makes the dryer a cost-effective solution for long-term use.

Versatility
KENKI DRYER is versatile and can handle various types of sludge, including those from wastewater treatment plants and other industrial processes. Its ability to dry lumpy and sticky materials makes it a valuable asset for a wide range of applications in urban mining and recycling.

In summary, KENKI DRYER’s unique mechanism, low-temperature drying, continuous operation, efficient and stable drying process, environmental and economic benefits, and long component life make it an ideal choice for drying metal sludge in the context of urban mining and recycling.

KENKI DRYER is a highly efficient and innovative drying system designed specifically for sludge. 

Patented Technology:
KENKI DRYER employs a unique, patented mechanism that ensures smooth and uniform drying, even for sticky and lumpy sludge. This prevents clogging and ensures that the entire sludge mass is dried thoroughly.

Low-Temperature Drying:
The dryer operates at low temperatures, preserving the material’s composition and making it suitable for recycling and upcycling. This is particularly important for inorganic sludge, which often contains valuable materials that can be recovered.

High Efficiency:
KENKI DRYER is highly energy efficient, using steam as the heat source to minimize fuel costs. This not only reduces operating expenses but also contributes to environmental sustainability.

Continuous Operation:
The dryer is designed for continuous operation, allowing for 24-hour, unattended drying. This maximizes productivity and reduces downtime.

Reduced Environmental Impact:
By reducing the volume of wet sludge, KENKI DRYER helps to minimize transportation costs and associated carbon emissions. Additionally, the dryer’s efficient use of energy contributes to decarbonization efforts.

Easy Maintenance:
The dryer is designed for easy maintenance, with low wear on parts and minimal downtime for servicing.

7. Versatility:
KENKI DRYER is not only suitable for inorganic sludge but can also be used to dry various organic wastes, making it a versatile solution for a range of applications.

In summary, KENKI DRYER offers a combination of high efficiency, environmental friendliness, and versatility, making it an excellent choice for sludge drying.

• Material to be dry: Inorganic sludge, which is difficult to dry
• Purpose of drying: Reducing industrial waste cost and amount
• Moisture content: 54.8％W.B. before drying, 7.4％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

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

Metal sludge is a byproduct generated during various industrial processes, primarily those involving metals or metal-containing compounds. It typically consists of a mixture of solids, such as metal oxides, hydroxides, and salts, suspended in a liquid medium, often water.

Common sources of metal sludge include:

• Electroplating: The process of depositing a metal layer onto a substrate often produces sludge as a byproduct.
• Metal finishing: Activities like polishing, grinding, and buffing can generate metal sludge.
• Metal manufacturing: Processes such as casting, machining, and smelting can create metal sludge.
• Wastewater treatment: Industrial wastewater treatment plants may remove metal-containing sludge from the effluent.

Metal sludge can be a significant environmental concern due to its potential to contain hazardous substances, such as heavy metals. Proper management and disposal of metal sludge are essential to protect human health and the environment.

Source：Gemini

While both inorganic and metal sludge are byproducts of industrial processes, there are some key differences between them.

Inorganic Sludge

• Composition: Primarily consists of non-metallic substances, such as minerals, oxides, and salts.
• Sources: Can be generated from various industries, including wastewater treatment, chemical manufacturing, and food processing.
• Examples: Sewage sludge, boiler sludge, and food processing waste.

Metal Sludge

• Composition: Contains a significant amount of metals or metal compounds.
• Sources: Typically associated with metal-related industries, such as electroplating, metal finishing, and metal manufacturing.
• Examples: Electroplating sludge, metal grinding sludge, and metal casting waste.

Key Differences:

Feature	Inorganic Sludge	Metal Sludge
Composition	Non-metallic substances	Metals and metal compounds
Sources	Diverse industries	Metal-related industries
Environmental Concerns	Can contain pollutants but usually less hazardous than metal sludge	Often contains heavy metals, posing a greater environmental risk

In summary, while both inorganic and metal sludge are industrial byproducts, metal sludge is more likely to contain hazardous substances due to its metal content. Proper management and disposal of both types of sludge are crucial to protect the environment and human health.

Source：Gemini

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

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