Sludge dewatering devices and their seemingly "mythical" benefits have become known across the wastewater treatment industry. However, not every WWTP is equipped with its own dewatering machine. So, what makes these systems so advantageous?
The primary benefits of having an on-site dewatering machine include reducing the cost of sludge cake disposal and transportation, enabling full automation, and—if you’re building a new WWTP—allowing for a more compact sump tank design. Additionally, if your facility currently relies on external dewatering services or uses an outdated dewatering machine, upgrading to a modern system can yield significant cost savings. This is because the expenses associated with frequent maintenance, part replacements, or outsourcing dewatering services can be substantially reduced by investing in an efficient, up-to-date machine.
For instance, screw presses are known for their energy efficiency and high performance, making them a sound investment for WWTPs aiming to optimize operations while cutting down costs. By installing the right dewatering system, you not only increase efficiency but also enhance the overall economic return of your facility.
Leave Replacement Concerns Behind
If you are considering replacing your existing dewatering system or equipping a WWTP with new technology, the selection process might feel daunting. We understand these concerns and offer expert consultations to help you navigate the decision-making process. Our team will assess both current and future conditions of your operations, ensuring that we address your specific needs and expectations in detail.
Investing in dewatering equipment is a long-term decision that requires careful consideration of all influencing factors. With our guidance, you can make an informed choice that delivers sustained benefits for years to come.
4 Essential Parameters to Consider When Selecting Dewatering Equipment
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Type of Sludge
The first step in selecting a suitable dewatering machine is understanding the type of sludge you need to process. Industrial and municipal sludges vary significantly in their composition, consistency, and pre-treatment processes. For instance, sludge from WWTPs that handle brewery wastewater may contain high levels of yeast, which can cause complications during flocculation. In such cases, choosing an appropriate flocculant is crucial for the efficient operation of a screw press. Testing sludge samples prior to equipment selection can identify these challenges and help with the choice of dewatering technology.
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WWTP Technology
Every wastewater treatment plant (WWTP) has unique characteristics that influence the choice of dewatering equipment. For example, WWTPs without digestion tanks produce "young" sludge with high water content bound within the cells, which is not possible to be dewatered through conventional mechanical dewatering. This can significantly impact the achievable percentage of dry solids (% DS) of the dewatered cake.
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Equipment Capacity
Determining the required capacity of the dewatering machine is essential and should align with your operational demands, including desired runtimes and target dry solids percentage. The expected sludge production can be estimated using the formula:
Equivalent Occurrence (EO)×0.06=Kilograms of Dry Matter per Day.
Each model of dewatering screw press has a defined dry solids capacity (kg/h). Using this formula allows you to select the appropriate model based on your production needs and available runtime. Ensuring that the machine's capacity matches your sludge production rate will optimize efficiency.
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Spatial Considerations
Spatial constraints within your WWTP should be a key consideration when choosing a dewatering machine. Smaller screw press models, such as the MP-DW-131, MP-DW-201, and MP-DW-301, can be easily accommodated in limited spaces. Larger models like the MP-DW-302 and higher may require special arrangements for transport and installation due to their size and weight. Alternatively, installing the equipment in a container unit can provide flexibility and enable installation outside the main WWTP building. Additionally, consider the distance for transporting sludge, rinse water, filtrate, and solids removal to ensure efficient workflow and minimal logistical issues.
By evaluating these four essential parameters—sludge type, WWTP technology, equipment capacity, and spatial constraints—you can make an informed decision when selecting the most suitable dewatering equipment for your facility.
Types of Dewatering Machines
There are several types of dewatering machines commonly used in wastewater treatment plants (WWTPs), each with unique features, advantages, and disadvantages. The most widely used options include screw presses, centrifuges, and belt presses.
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Screw presses
Screw presses are considered the most energy-efficient and quiet dewatering machines. They are ideal for WWTPs seeking a reliable and straightforward solution. The slow-rotating screw shaft moves through a dewatering mechanism composed of fixed and moving rings. As the sludge progresses through the system, it is compressed until it reaches the pressure plate at the end, where a dry cake is discharged. The separated filtrate drips into a catch tank beneath the dewatering mechanism. Screw presses are valued for their simplicity, durability, and low operational costs. -
Centrifuges
Centrifuges have a long history of use in dewatering applications and are known for their high rotational speed (RPM). While they have 10 to 20 times higher energy consumption compared to other technologies, they can achieve higher % of dry solids (DS) content in the output. The dewatering process relies on the density difference between solids and liquids, which are separated as they spin rapidly within the centrifuge bowl. -
Belt filters
Belt presses use a simple yet effective technology that is relatively easy to maintain. They work by squeezing the sludge between two moving belts to remove water. While belt presses typically require a large installation area and yield lower dry matter content compared to screw presses or centrifuges, they are often used when space and cost are not limiting factors. Belt presses are a good option for facilities seeking a low-maintenance solution with moderate performance.
In-Field Testing of the Dewatering Machine
Before selecting a dewatering unit, we recommend conducting an in-field test at your wastewater treatment plant (WWTP) during actual operation. Testing the equipment in your specific environment provides valuable data on its performance and helps determine which type of dewatering equipment is best suited to your needs.
Selecting the Right Dewatering Machine
Choosing the most suitable dewatering system involves more than just evaluating technical parameters; it also requires consideration of your operational preferences and budget. When making a decision, consider not only the initial investment but also the long-term costs associated with operation and maintenance. Service expenses can be minimized through regular inspection and upkeep, which will extend the equipment’s lifespan and enhance its overall return on investment.
Installation and Training Process
Once the equipment is ordered and delivered, the next steps are installation and training. During installation, our technicians ensure that the equipment is correctly positioned and fully integrated into your WWTP system. The training phase will cover the operation, setup, and maintenance of the equipment to ensure seamless operation. Following installation, we continue to offer technical support and can make any necessary adjustments to the system as required.
If you have any questions or need further assistance, feel free to reach out to us. We're here to ensure you get the best possible performance and value from your equipment.
Service and Warranty Extension
Routine maintenance is essential for ensuring the long-term, reliable performance of your dewatering system. We recommend conducting a comprehensive inspection of your equipment at least once a year. This process should include evaluating the condition of parts and replacing any that show signs of wear. Similar to how a car requires an oil change after 10,000 kilometers or annually, our equipment benefits greatly from regular servicing. Such proactive maintenance helps prevent potential damage and ensures optimal performance.
Additionally, cleaning the equipment after each use is crucial to avoid material hardening on moving parts. When left unaddressed, hardened material can act as an abrasive, accelerating wear on components such as rings and worm shafts.
Investing in the right dewatering equipment is a strategic decision that can significantly impact your operational efficiency and profitability. By considering all these factors, you can select a solution that delivers superior performance and value over the long term.
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