Sludge Dewatering With a Screw Press

Sludge dewatering is an integral process in wastewater treatment plants and offers enormous potential savings when implemented correctly.

A screw press offers the latest in cutting-edge technology with high performance, combined with compact design and low energy usage. Furthermore, its bi-sequent cleaning feature helps lower maintenance costs as well as sludge/flocculant consumption as well as water consumption significantly.

Water Serviceable Range

Water removal from sludge is essential in wastewater treatment facilities as it reduces its size and weight, making disposal much simpler and cost-effective. One of the most frequently employed dewatering technologies is a screw press which has been around for several decades but recently experienced significant advancements.

The basic operating principle of the screw press is straightforward. Sludge flows into a flocculation tank where polymer is added to help solid particles aggregate into thickened "flocks". Once this process has completed, flocks are mixed with the remaining sludge water before being carried by screen basket into the screw cylinder for mixing with its slow rotation and decreasing pitch to drain supernatant into dewatering collection trough below and produce filter cakes with up to 20% dry solids content.

Screw presses offer other advantages beyond their high dewatering capacities, including lower maintenance costs and downtime compared to centrifuges. Furthermore, their design requires fewer moving parts which leads to reduced maintenance costs and downtime as well as allowing different flow rates allowing it to work with various sludge types and conditions without an intermediate thickening step reducing capital and operating costs.

Sludge Serviceable Range

Nihao Industries screw sludge press provides cost-effective dewatering treatment of biological and physical-chemical sludge types alike, producing dewatered cake with high dry solids content for efficient disposal of the remaining volume of sludge.

Sludge is gradually thickened and dewatered along its entire path within the vessel using inner pressure, leading to impressive dewatering efficiency. This is especially significant when dealing with abrasive sludge since a high dewatering rate reduces load from centrifuges or filter presses.

High sludge density results in greater dewatering capacities compared to other equipment types at lower feed flows, making the sludge dewatering process ideal for dealing with oil and fat-laden abrasive sludges as well digested sludge which provides slow release nitrogen/phosphorous sources similar to farmyard manure. This makes digested sludge an invaluable source of slowly available nitrogen/phosphorous sources similar to farmyard manure.

The unit can be used for an array of applications, such as wastewater treatment plant (WWTP) secondary sludge, abrasive biological sludge, septage and grease trap sludge, food processing wash down sludge, biosolids, animal waste and industrial sludge. It offers an attractive alternative to centrifuges or belt presses as it features clog-free functionality with reduced power and water consumption and easy operation and maintenance requirements.

Power Serviceable Range

Screw Press Sludge Dewatering Machine's energy requirements are impressively low (roughly 5kWh/tTR). This is due to combining thickening and squeezing into one unit, thus dramatically decreasing energy requirements. Furthermore, its auger rotates at 5rpm for greater energy savings while still being protected by a cylindrical screen basket which allows water to pass while keeping solids contained within.

Also, proper conditioning and polymer dosing of the sludge boost the dewatering process by encouraging particle aggregation, leading to higher cake dryness and separation efficiency. Automatic control of the dosing system enables machines to quickly respond to fluctuations in sludge consistency without needing manual readjustments - saving both time and effort!

Sludge is transported via transport screw to the dewatering zone, where it is squeezed with the rotating Archimedean screw against a filter cake to reduce moisture content further. Filtrate from this process is collected in either a liquid collecting tank or returned back to the treatment plant while any excess moisture content can be further reduced using dewatering/drying chambers - with dry solids content of up to 20% achievable without an intermediate thickening step - saving both investment and operating costs while providing high quality dewatering processes. In addition, this system features a unique cleaning mechanism which ensures no blockages on discharge end cloggings during processing sludge dewatering processes.

Maintenance Serviceable Range

A screw press is easy to operate and requires minimal maintenance, while its inclined installation of dewatering drums prevents sedimentation and makes cleaning work simpler.

Screw presses require less energy and noise emissions than centrifuges and produce significantly reduced levels of noise and vibration, thus eliminating the need for soundproofing and vibration isolation measures. They also use less water for dewatering sludge which may lower utility bills.

Screw presses are widely used for sludge dewatering to produce much drier cakes than other methods, which makes the cake suitable for disposal or reuse in other applications. They are commonly employed to dewater septage sludge, grease trap sludge, animal manure and other waste streams along with industrial biosolids.

Nihao sludge dewatering machines can be custom designed to suit various sludge types and dewatering requirements, providing efficient dewatering with low power consumption without compromising performance or quality.
Sludge residence time in the screw press can be customized according to individual requirements for optimal dewatering efficiency and optimal cake properties.