Seven Hills International Limited


 - Dewatering Systems



Gravity Belt Thickening Systems

Our range of Gravity Belt Thickening System has been developed to meet the most stringent bio solids thickening standards.

This fact also ensures that all models of belt press units are totally enclosed creating work areas which are clean, dry, odour free with low noise levels.

The Gravity Belt thickening range varies from small to large applications where floor space is premium. As with all our ranges, Gravity Belt Thickening systems can be supplied as fully integrated packages.

Turnkey System from Seven Hills

A turnkey system from Seven Hills International Limited includes a belt filter / thickener, polymer preparation system, sludge handling system and control system.

Additional high performance elements include the Sludge Expert system for automated process optimisation and the Dual-Mode feature for maximum flexibility with final cake dryness. Seven Hills designs and manufactures all system components, ensuring that all elements of the system work in harmony.

A turnkey system guarantees maximum sludge conditioning, maximum filtration, maximum cake dryness and maximum ease of operation and maintenance.

For more information view our products.

  • Single belt system for smaller capacity bio solids dewatering or thickening applications
  • Flexible, high performance thickening systems
  • Stainless Steel
  • Cost effective alternative
  • Higher dry solids content
  • The dry solids content of the thickened bio solids may be set by site personnel to suit specific requirements



Series Alpha 10000 Belt Press System

Series Alpha 10000 has evolved from the very successful series 1, sludge press range which, over the year has set the standard for simple reliable dewatering of extended aeration bio solids.

There are Series Alpha 10000 belt units for both Dewatering and Thickening applications.

The Dewatering units are particularly suitable for the smaller site where the savings on capitals cost far outweigh the additional disposal cost of a slightly greater volume of bio solids cake.

The Thickening units, complete with patented dual mode facility have all the features and application flexibility of the larger series Alpha 40000 range. They provide an exceptionally cost effective method of bio solids thickening when long daily working hours are permitted.

The dry content of the thickened bio solids may be set by site personnel to suit the site specific requirement.

Both Dewatering and Thickening systems are available either as fully integrated skid packages complete with all pumps. Polymer systems, controls etc. or separate components.


Series Alpha 10000 System Options Include
Configuration Skid package Components
Series Alpha 10000 unit Thickens or dewaters Dewaters only
Progressive Cavity sludge Feed Pumps Mechanical Control Inverter Control
Polymer Preparation System Automatic        Batch
Raw Polymer Type Powder Liquid
Polymer dosing Pump(s) Mechanical Control Inverter Control
Wash Water System Included           Excluded
Wash Water Source Potable Water Final Effluent
Cake Handling Method Conveyor Cake Pump
Trailer & Skip Filling Automatic Manual
Sequence Control System Automatic  
Auto Process Control Monitor filtrate quality  
Odour Enclosure Fully Enclosed Partially Enclosed
Installation Source Seven Hills By Customer


Series Alpha 10000 Range
Alpha 10750
Alpha 11250
Alpha 11500
Belt width (mm)
Filtration Area Sq m
Pressure rollers
Typical Capacity (kg dry solids / Hour
Thickening SAS from 0.6 % to 6%







Dewatering activated bio solids
From 1% to 12% - 14 % typical 


Typical Applications
Dewatering Application
  • Food Production Industry
  • Dairy and Meat Plants
Thickener Application
  • Thickening SAS prior to digestion (typically under automatic time control)
  • Thickening both wastewater and clean water bio solids to minimise tinkering costs

Series Alpha 40000 Belt Press
  • Up to 5m Belt Width
  • 'Double Deck' Models are available to make best use of floor space for large capacity machines
  • Dry solids content can be simply adjusted
  • Thickening occurs prior to digestion
  • Can be fitted with patented dual mode system. Please contact us for more details.



Series Alpha 40000 series of gravity belt thickeners have evolved to meet stringent bio solids thickening standards.

In addition to gravity thickening bio solids in the traditional manner series Alpha 40000 thickness may be fitted with the patented dual mode system. This presses a selected proportion of the bio solids load and allows the dry solids content of the thickened bio solids to be simply adjusted (typically in the range 5% to 10 %) to meet specific requirements.

“Double Deck “models are available which makes best use of floor space for large capacity machines.

The complementary Series Alpha 10000 series is especially suited to medium and smaller capacity systems



Series Alpha 40000 System Options Include
Dual mode pressure roll Yes       No
Filterate sump  Cast in Floor Stainless Steel
Odour Enclosure Fully Enclosed Partially Enclosed
Progressive Cavity sludge Feed Pumps Mechanical Control Servo Control
Polymer Preparation System Automatic  
Raw Polymer Type Powder Liquid-Both
Polymer dosing Pump(s) Inverter Control  
Wash Water System Included Excluded
Wash Water Source Potable Water Final Effluent
Thickened sludge Handling Method Auger and pump Gravity
Trailer & Skip Filling  Automatic Manual
Sequence Control System Automatic  
Auto Process Control   Fully Automatic Monitor filtrate Quality
Installation Source Seven Hills       By Customer


Series Alpha 40000 Range
Alpha 41250
Alpha 42000
Alpha 42500
Alpha 44400
Alpha 44500
Belt width (mm)
Filtration Area Sq m
Typical Capacity (kg dry solids / Hour)
Activated Bio solids (0.6 % to 6%)
Mixed Primary and Secondary (60:40)


Typical Application
  • Municipal and Industrial wastewater treatment works.
  • Thickening prior to digestion
  • Thickening to minimise transport costs or storage tank capacity.
  • Secondary bio solids, primary bio solids singly, mixed or co-settled.
  • Clean water bio solids