MONOBELT® belt press
Descriptionback to top
TEKNOFANGHI Ltd from Milan / Italy specialises in sludge dewatering equipment and is well known throughout the world for their outstanding dewatering systems - among others the unique sack filter system called DRAIMAD®, which also has big influence on sludge handling technology in Poland. The belt press MONOBELT®.

Operating principlesback to top
treating biological sludge
The MONOBELT® belt filter press is an entirely new patented design. It comprises of two units, a pre-thickener and a sludge press. The pre-thickener performs the initial solid/liquid separation stage, taking sludge solids concentration from 0,5-3% up to 5-12% for biological sludge and up to 18% for mineral sludge. The dynamic thickener, mounted as a standard component on all MONOBELT® presses, is not a conventional drum filter, as it comprises of an Archimedean screw and a cloth covering the screw to form a completely integrated drum.
In this way, the sludge is continuously stirred, aiding the drainage of the "free water" (water surrounding the "flocks") and the "interstitial water" (water inside sludge "flocks").
The stirring motion inside the thickener helps to complete the flocculation process as required. This is the ideal situation even when the sludge is very liquid (0,5%). The application of an integrated pre-thickener enables dewatering of very low concentration sludges. Pre-thickeners of this kind are supplied under the name of SCRUDRAIN® as independent thickeners for sludge thickening before digesters.

The name MONOBELT® means one single belt. In fact the belt press has two belts, which is common to all belt presses on the market. As the weakest point of the belt is the joint, MONOBELT® uses an endless belt with spliced joint and no zippers or clips. The second belt of the machine is a filter cloth fixed on a large perforated cylinder. This filter cloth is fixed on the cylinder but has no traction stresses, giving a very long life, as much as eight times longer than other belts.
The lifetime of an endless belt is about 3 - 4 times longer than a joined one. These unique advantages make it possible to reduce the maintenance costs by over 50% (i.e. belt replacement costs).
The simple construction gives further maintenance cost reduction due to fast and easy operation and maintenance. Simple construction means also that despite of high technical quality, the product price is very competitive.

The machine weight is low so it does not require any special foundation. The MONOBELT® operation principle is clear and includes all necessary stages for dewatering.
The thickener is positioned above the belt press, so that the pre-thickened sludge is discharged directly to the Low Pressure Draining Zone with no further requirement for pumping.
The low pressure draining zone is over 2 meters long and inclined at 7o. This area is composed of three adjustable press baffles and two sludge breaker combs with nylon screw shafts. The first press baffle spreads sludge over the cloth, while the other two press sludge onto the underlying cloth to obtain drier cakes. The two sludge breaker combs with screw shafts separate sludge layers which could prevent de-watering on the filter cloth.
During the passage through the low pressure draining zone, the endless belt is supported by three tubes. These tubes alternate the cloth flexure axis, breaking the surface tension and allowing water drainage. These tubes also act to wring out the filter cloth aiding further drainage.
At the end of the low pressure draining zone, the sludge falls into the hopper of the Wedge Zone where it is spread by pressure and guided by Vee sides.
The Vee sides have a very specific shape, designed to guide the sludge until the two cloths touch where the pressure on the sludge is gradually increased. The Vee sides prevent the sludge from being squeezed out the sides, which often happens on traditional belt presses.
After passing the Wedge Zone, the sludge then reaches the Maximum Pressure Zone. This area, 1,5m. long, is where the two filter cloths contact, keeping the sludge under pressure for over a minute. Here the sludge is subjected to very strong dewatering forces.

  • The first force is due to the compression of the endless belt on the cloth covering the perforated cylinder. This force is provided by pneumatic actuators and can be varied, even as the machine is operating, with the appropriate pneumatic valves.

  • The second, is the tangential shear force generated by the belt movement, transmitted by the driving motor on the rotating perforated cylinder. The endless belt is moved only by friction from the filter cloth on the perforated cylinder.

MONOBELT® belt presses have a complete belt washing group. This system includes a pump (mounted on the side of the machine and connected to the control panel), automatic cleaning and collection filter, complete with gauges for precise pressure control, and water feed manifolds fitted with polypropylene ProMax® quick jet spray nozzles. The filter, has a finer mesh than the spray nozzle orifices so that any impurities in the water are removed to avoid clogging of the spray nozzles.
Clean treated effluent water can be used for washing of the belts in order to save the cost of water.
The alignment and tension of the belt are controlled by using pneumatic actuators.
The main control panel can provide automatic operation of the sludge and poly pump. Sensors monitor the operation of the machine and halt operation in the event of malfunction.
The producer offers the wide range of products, including sludge and polyelectrolyte screw pumps and manual and automatic units for polyelectrolyte preparation. It's worth mentioning the extremely low energy consumption and low installed power required by MONOBELT®.
The belt press MONOBELT® is completly made of AISI 304 stainless steel.

Advantagesback to top
  • low capital investment,
  • unique and compact construction,
  • combination pre-thickener and belt press - possibility of dewatering sludges with low initial D.S. concentrations,
  • higher reliability,
  • easy operation and maintenance;
  • low operating and maintenance costs,
  • endless belt with special spliced seam (2 - 3 fold longer life),
  • 4 - 5 fold lower machine dead weight - no special foundations required

Technical databack to top
TYPE NP 08 NP 12 NP 15
Belt width [mm] 800 1200 1500
Length [mm] 3300 3300 3300
Width [mm] 1500 1900 2200
Height [mm] 1930 1930 1930
Flow m3/h 2-6 3-10 5-15
Installed power [kW] belt press 0.62 0.92 1.3
Wash pump 2.2 2.2 3

Dimensionsback to top

TYPE weight [kg] A B C D E F G H
NP 08 1500 1500 1200 200 1900 3300 180 1930 1800
NP 12 1700 1900 1600 200 1900 3300 180 1930 1800
NP 15 2000 2200 1900 200 1900 3300 180 1930 1800

Referencesback to top
The MONOBELT® belt presses are manufactured in Milan and exported to many countries in Europe, Asia and America. The MONOBELT® belt presses have been installed in Poland since 1995, where they became popular - due to process advantages, low capital investment and operation cost.
This system was installed (by end 2007) in more than 150 municipal and industrial sewage treatment plants in the country. The MONOBELT® belt presses are made according to CE European standard.
The MONOBELT® system was rewarded a medal from the Industrial Chamber "Wodociagi Polskie" at the International Fair WOD-KAN '98 in Bydgoszcz.

For more information about locality and references, please contact us.