Salsnes Filter Overview
Salsnes Separation ( S.A.) Pty Ltd
Devlyn Fraser
Product Introduction

The purpose of the Salsnes Filter

1) Separation & dewatering of solids, leading to
the reduction of the (TSS) Total Suspended
Solids in municipal effluent

2) Separation & dewatering of solids in Industrial
effluent, with the aim of lowering the SS, COD and
BOD, effectively lowering effluent billing costs, as
well as possible reductions in operations &
maintenance costs.
Technical Overview








2 Models, SF 2000 & SF 6000
Manufactured in 304 & 316 S/Steel
Hydraulic loading of 70- 575 m³ / Hr
Endless Cloth Filter, Woven Polyester, 0.1- 1.0
mm pores (785 Microns Thick)
40-70 % removal of suspended solids
The cake (dewatered Sludge) 25-45 % Dry
substrate
Weight : 375 Kg (SF2000)
725 Kg (SF6000)
Energy Consumption: 2.5 Kw (SF2000)
4.2 Kw (SF6000)
Process Description

Effluent inflow through inlet tube
 Effluent filtered through an endless Filter Cloth
 Removal of 40-70% of suspended solids
 The filtered water is released through outlet-pipe
 Suspended solids are conveyed by filter cloth &
dumped into a sludge compartment
 Excess sludge removed from cloth by an Air knife
 Primary Sludge dewatering is facilitated by
gravity during transport of the sludge to the
trough
Process Description

Secondary dewatering of sludge is facilitated by screw press
compacting the sludge in the press cylinder
a)
Excess water is drained via secondary outlet

Compressed, dewatered sludge (cake) is released via a
spring loaded lid on the press cylinder

Excess Fat deposits are removed from cloth twice per day
via Hot water spray (20 Ltrs Each) - Adjustable

On/Off & operating speed is controlled by pressure
transmitter, measuring the level of inflow, to achieve optimal
balance between inflow & the filters filtration properties

Process is completely automated, incl. Cleaning = minimal
maintenance
Applications
A) Overview of Expanded process at Municipal : WWTP’S
PST
Solids (underflow)
Water (Overflow)
DIGESTOR
Digested Sludge
AERATION BASIN
Biological treatment
Supplies O2 to Microbes
Microbes eat organics,
1. Belt Press
2. Irrigated to Land
3.Composted
4.Dewatered - Incinerated
pathogens & bacteria
Overflow
CLARIFIER
Chlorine Gas
Clean disposable water
Ponds
Rivers
Industries
Underflow
Activated Sludge
Biologically active
Waste activated Sludge
Sludge returned to digestor
Co-Digesting
Activated Sludge
Returned to Aeration basin
to balance Microbe population
Drying beds
Mechanical dewatering
Irrigation to land
Applications Cont.

Salsnes Filter removes SS in parallel to
PST, possibly allowing
decommissioning of the digester.

Sludge cake to be stabilised (composted) & sent
to landfill or other

Alternately sludge must not be compressed &
dewatered, & sent to digester to neutralise
biological activity.
Installation Options - WWTP




Relieve overloaded capacity – SF installed prior
to PST
SF installed after PST to reduce loading on
aeration basins
SF installed parallel with PST, tapping back to
aeration basins, removing excess flow rates from
PST
Reduce wear, maintenance & re-furbishment
costs on pumps, if installed prior to pump to
remove abrasive materials
Applications to avoid in WWTP

Do not install SF after PST on the digester feed
line, SF not able to deal with digested sludge.

Do not load SF with sludge treated with
Flocculants (polymers), possible application for
very limited flocculant dosing may be acceptable.
Industrial Applications

The following are possible applications for SF:

Sugar Mills- Juice filtration
Tanning Processes
Paper Mills
Canneries
Fish, Poultry food processors and Abattoirs
Fruit Juice Processing
Biofuel Processes
Breweries
Screening Before Reverse Osmosis – Desalinisation
Animal Feed Manufacturers
Grain based industries










Industrial Applications Cont.

It is imperative that the SF does not be
considered as a means of removing Grit (Sand)
from Effluent.

The SF is able to contend with approximately 10%
Grit in Effluent.

One must bear in mind that the higher the Grit
Loading in the Effluent, the higher the wear and
maintenance costs of the SF will be.
SF Benefits - Industrial Processes

Reduced effluent SS, COD, BOD, Efficiently Reducing
Effluent Billing Costs.

Recovery of some Protein content in SS for Re-processing
in the Rendering Process that may have income generating
benefits.

The refining of Sugar cane and Fruit Juice Extracts,
including the recovery of SS for further processing.

The recovery of Paper Fiber for Reprocessing.
SF Features – Benefiting Industry
and WWTP’s

No Chemicals

Negliable Water Consumption

Recovers and Dewaters Sludge in Combined Process


Outstanding Results : 40 – 70 % SS Removal
•
25 – 45 % Dry Substrate
Low Maintenance Costs

Easy Repair and Maintenance Procedure
SF Features – Cont.

Low Power Consumption and Running Costs

Self Cleaning – Automated

Level Sensor Controls Speed and Optimises SF Filtering
Performance at various flow Rates – All Automated.

Exceptional After Sales Service and Back Up

Compact Design – More Placement Options

Compact and Light – Easily Maneuverable
SF Features – Cont.

Refined for South African Applications

Globally Recognised, Approved and Industry Proven

Recovery of SS for re-processing if required

Substantial Effluent Billing Cost Saving = Feasible
Payback Term
PHOTO’S
PHOTO’S
PHOTO’S
PHOTO’S
*THE END !