Multi-Disc Screw-Press Dehydrators MDQ Series

Multi-Disc Screw press Dehydrators MDQ Series feature unitized construction that integrates all necessary accessories, and can be more easily installed and are very compact compared with belt presses and centrifugal dehydrators. The dehydrators boast lower noise, reduced energy consumption, and require less water for flushing, thus providing an economical and eco-friendly solution to dehydration applications.

Multi-disc screw press dehydrators utilize both gravity filtration and screw displacement compression systems. The pitches of the screw blades are gradually narrower toward the cake outlet in order to reduce the volume of cake, so the coagulated sludge that has been concentrated by gravity filtration is dehydrated by compression.The dehydrator main unit requires lower motor output and the filtration surface consists of a multiplicity of self-cleaning capable discs, and seldom clogs. Thus, the dehydrator can be used continuously. The main unit of the dehydrator is of multi-shaft design. Therefore, when two or more main units are configured into one machine, any individual shaft can be repaired or serviced without interrupting dehydration operations.Multi-disc screw press dehydrators can coze with a wide range of sludge concentrations, and also stably dehydrate sludge that contains high oil content.

MDQ Series

Tsurumi’s technology is constructively at workin a diversity of sites and applications.


  • Excess sludge from biological processes
  • DAF froth
  • Various types of mixed sludge
  • Coagulated sludge


Tsurumi’s multi-disc screw press dehydrators are available in wide lineup, with treating capacity in a range of 3 to 216 kgDS/h, and with five shafts at maximum. Users can select the best equipment from 13 models according to the size of targeted treatment plant.

The MDQ/MDC series features energy-saving construction designed to dehydrate sludge by “gravity filtration + screw volume reduction.” The equipment is of compact unitized construction with all of the necessary accessories and control panel mounted on a common base*, and therefore can be readily installed in very limited floor space. * Not applicable to the MDC-series.

Operators can begin automatic operations of the dehydrator and related accessories by simply and easily operating the included control panel

The filtration surface consists of a multiplicity of discs and a self-cleaning mechanism, therefore it seldom clogs and the equipment can run continuousl

The equipment can stably dehydrate even sludge that contains high oil content. The dehydrator is an optimum solution for treating oily sludge such as DAF froth (mixing with excess sludge) at food processing plants, which filter cloth systems and centrifugal separation processes cannot readily handle. Thus, the equipment boasts a higher solid capture rate.

The dehydrator has both a gravity concentration section and compression dehydration section, and therefore can cope with a wide sludge concentration range of 0.5 to 2.0%.

Because the equipment is constructed to avoid clogging, flushing is not needed in order to restore the original filtration performance. Only showering with a minor amount of water is necessary to wash away sludge that oozes from the dehydration section. Thus, the amount of flush water needed is minimal, and routine maintenance work is not needed.

The dehydrator main unit features a semi-enclosed construction, and runs at an extremely low speed, therefore sludge does not splatter from the equipment. The dehydrator is of eco-friendly design that generates low noise and vibrations, and emits virtually no odors.

When two or more dehydrator main units are configured into one machine, any individual shaft can be repaired or serviced without interrupting dehydration operations.

Criteria for Selecting a Model

  • Sludge Concentration
    Less than 2% → Multi-Disc Screw Press Dehydrators MDQ / MDC
    2% or higher  → Multi-Disc Dehydrators JD
  • Inorganic Content
    Less than 40% → Multi-Disc Screw Press Dehydrators MDQ / MDC
    Less than 60% → Multi-Disc Dehydrators JD


Mechanical Principle

The main unit of the multi-disc screw press dehydrator contains a multi-disc mechanism where ring-shaped “fixed discs” and “movable discs” are alternately arranged at a regular clearance around a “screw shaft.” The main unit consists of a “support frame” that supports the multi-disc structure and a “dam plate” at the end of the screw shaft.

  • Movable Disc Bore Surface Sliding Contact System
    The bore of the movable disc remains in contact with the outer circumference of the revolving screw blades while sliding, therefore the passage area is constantly cleaned, allowing the dehydrator to stably treat sludge without clogging.
  • Dehydration Process
    The sludge transported by the screw is gradually compressed as the screw pitch narrows in the direction of travel, and is further compressed by the dam plate at the end of the shaft and delivered out of the dehydrator.
  • Concentration Process
    Most water content in the flocculated sludge flowing into the dehydrator main unit flows through the clearances (gaps between the fixed discs and movable discs) in the multi-disc structure and is then delivered outside the dehydrator by gravity filtration.

MDQ Flow Sheet


Model Treating


Screw Shaft Length Width Height Dry Operating
MDQ-101 3 - 6 0.6 ɸ 100 X 1 1800 900 1800 400 1000
MDQ-102 6 - 12 0.7 ɸ 100 X 2 1800 900 1800 500 1150
MDQ-103 9 -18 1.0 ɸ 100 X 3 1850 1100 1800 700 1550
MDQ-104 12 - 24 1.25 ɸ 100 X 4 2100 1500 2050 900 1950
MDQ-105 15 - 30 1.35 ɸ 100 X 5 2100 1500 2050 1000 2100
MDQ-201 9 - 18 1.05 ɸ 200 X 1 2650 1200 2050 700 1600
MDQ-202 18 - 36 1.25 ɸ 200 X 2 2650 1200 2050 900 1900
MDQ-203 27 - 54 1.8 ɸ 200 X 3 2650 1500 2050 1200 2550
MDQ-204 36 - 72 2.35 ɸ 200 X 4 2800 2100 2050 1600 3550
MDQ-205 45 - 90 2.9 ɸ 200 X 5 2800 2100 2050 1800 3850
MDC-351 36 - 72 0.95 ɸ 350 X 1 3770 1140 2005 1300 1830
MDC-352 72 - 144 1.85 ɸ 350 X 2 3930 1460 2030 2300 3310
MDC-353 108 - 216 3.15 ɸ 350 X 3 4220 1810 2200 3300 4840
  • The treating capacity will vary depending on the characteristics and concentration of sludge.
  • Applicable sludge must be organic and have an ignition loss (VTS = Volatile Total Solids) of more than 60% and a concentration (TS) of 0.5 to 2.0%.
  • The motor output means the total motor output of the MDQ/MDC dehydrator that includes the dehydrator main unit, but does not cover motor output of the sludge conveying/feed pump, chemical feed equipment, etc.
  • The sludge conveying/feed pump, chemical feed equipment, chemical feed pump, etc. outside the MDQ/MDC dehydrator are not included.