Considerable amount of fluid fibrous sludge, that is necessary to liquidate as economic as possible, rises in some processes (for example in the process of paper production). The first step in sludge liquidation is the massive reduction of its volume. For this purpose the high-pressure belt presses proved very good in the paper industry.

 Standard high-pressure belt presses produced by the company VANEX are characterized by:

·         Two gravitation sectors with total length of 6 m, where at the same time the sludge is turned down. Thanks to these long gravitation sectors sludge with low incoming dry matter (circa 1%) can be processed.

 ·         Long passage time through the pressure sector. The length of this sector is circa 3 m. Thanks to this length and to the long passage time through the pressure sector a thick sludge layer can be created before sludge enters into the high-pressure sector. This thick sludge layer is necessary in order to achieve a high output value of dry matter.
 ·         The high-pressure belt press VXVT is characterized by an active high-pressure sector in which at the same time the high-pressure cylinders play the role of the driving cylinders.

In this manner extreme high pressures can be achieved with minimum sieve tension.

Pressure can be increased till the maximum torque of the high-pressure cylinder drive is achieved.

The high-pressure belt presses not having designed the high-pressure sector in this way, have to increase the tension of pressing sieves together with the increasing of pressure between the two high-pressure cylinders and in this manner to avoid the slippage of separate driving cylinders.

There is a limit in increasing the sieve tension – the sieve tensile strength.


Since the high-pressure belt presses of the company VANEX can be operated thanks to their active high-pressure sector with minimum tension of the sieves, it is possible to use sieves with removable joints. This considerably simplifies the replacement of worn sieves in comparison with machines, that on account of using extreme sieve tension have installed endless sieves without removable joints.


The speed synchronization of all driving mechanism is solved through frequency converters.

The main frame and the cylinders of the belt press are made from standard steel.

The surface of the press and of other components within the line delivered by VANEX is treated except with 100 micron zinc-metallization also with three layers of two-component polyamide hardened epoxyd coating composition, with high content of solid particles, with good wetting facility and low water permeability.


All other components are made from stainless steel and polypropylene. Optional company VANEX can deliver the belt presses also in stainless steel version.


Company VANEX delivers five basic types of high-pressure belt presses, their specifications are presented in the table. Values that are presented in the table are values achieved in process with standard high-pressure presses.


These presses are constructed conceptually in the manner that enables processing of the majority sludges occurring in the paper industry and achieving maximum dry matter content and maximum performance.

Company VANEX carries out compressibility tests of concrete sludge for concrete belt press. Following the results of these tests, the content of output dry matter and performance of the belt press, processing the tangible sludge, can be relatively exactly estimated.


Typ of
High-Pressure Belt Press

Filter Belt Width

Informative Performance of the Belt Press
(m3 . h-1)

Dry Matter Content of Incoming Sludge

Dry Matter Content of Outgoing Sludge from the Press for Sludge with Negligible Ash Content

Dry Matter Content of Outgoing Sludge from the Press for Sludge with Ash and Fibre Content in Relation 1:1

Power Consumption



10 – 15
1 – 5
40 – 48
45 – 60
 VXVT 10
12 – 18
 VXVT 12
15 – 22
 VXVT 15
18 – 30
 VXVT 20
25 – 40