Three Key Parameters for Equipment Selection

In the process of selecting dewatering equipment, throughput, feed sludge concentration, and dry solids load are usually the primary parameters discussed.

Throughput: the total volume of sludge entering the dewatering unit per hour.

Feed sludge concentration: the proportion of solids in the sludge fed into the dewatering unit.

Dry solids load: the mass of dry solids obtained by theoretically removing all water from the discharged sludge.

In theory, these three parameters can be interconverted:

Throughput × Feed sludge concentration = Dry solids load

For example, with a throughput of 40 m³/h and a feed sludge concentration of 1%, the dry solids load can be calculated as:

40 × 1% = 0.4 tonnes

Ideally, knowing any two of these parameters allows the third to be calculated, providing a reference for equipment selection.

However, in real projects, relying solely on calculated values may overlook key site-specific factors, potentially resulting in mismatched equipment or suboptimal operational performance.

Impact of Feed Sludge Concentration

In practice, feed sludge concentration affects which parameter takes precedence during selection:

- At low feed concentrations, greater attention should be paid to throughput per unit time.

- At high feed concentrations, dry solids load often becomes the critical reference parameter.

Selection priorities may vary depending on project conditions. During the enquiry stage, the aspects that customers focus on often differ from the information engineers need to verify before providing a quotation.

Customer Focus During Enquiries

When customers enquire about dewatering equipment, they typically focus on:

- Equipment model or specification

- Whether the capacity meets their requirements

- Approximate budget range

Some customers may have preliminary ideas regarding equipment type or specifications, such as preferred belt width or technology, and expect a prompt quotation.

These points are a normal step in project development and serve as the starting point for communication.

Further Information Engineers Need to Confirm

Before finalising quotations and solutions, engineers usually need to confirm project-specific information to fully understand the context and ensure proper equipment selection.

Sludge Type

Sludge from different sources varies in physical properties and treatment difficulty.

Municipal and industrial sludge often differ in composition, moisture content, and response to dewatering processes.

Identifying sludge type helps engineers assess equipment suitability more accurately.

Feed Conditions and Target Moisture Content

Feed conditions determine operating load, while the target moisture content defines dewatering performance requirements.

Different projects may have different expectations for cake moisture content, influencing process priorities.

Clarifying feed conditions and target moisture helps engineers evaluate long-term operational compatibility.

Existing Dewatering Equipment on Site

Confirming whether dewatering equipment is already installed, and whether the project is a capacity expansion or first-time installation, helps engineers fully understand project requirements.

Selection logic and configuration priorities may differ depending on the situation, and early clarification reduces later adjustments, ensuring smooth integration.

Water and Chemical Consumption Requirements

Water and chemical usage are major operational costs for dewatering systems.

Some projects have strict requirements for operational costs at the selection stage, which influence equipment configuration and process parameters.

Early understanding allows engineers to balance performance and cost during solution matching.

Site-Specific Conditions

Before selecting equipment and matching solutions, engineers typically assess the wastewater plant’s site conditions to determine feasibility of installation, operation, and maintenance:

Installation space and layout: available space, headroom, and access.

Process integration: position of the dewatering unit within the treatment process.

Operation and management: shift patterns and management practices.

Utilities and foundations: electricity, water supply/drainage, and civil foundations.

Project type: new build or retrofit, influencing design priorities.

Importance of Adequate Early Communication

If project conditions are not fully communicated during the enquiry stage, the following issues may arise:

- Actual treatment capacity differs from expectations

- Frequent parameter adjustments required during operation

- Increased communication and coordination costs during project execution

Such issues are not necessarily caused by the equipment itself but often result from incomplete information during the early stages.

Therefore, the safest approach is to first clarify the basic project conditions, then match equipment and solutions to the actual operating context.

Thorough early communication ensures that equipment capabilities align with site requirements, improving selection accuracy, reducing later adjustments, and enabling smoother and more stable project operation.