Hydro International Hydro-Sludge Screen User manual

© 2018 Hydro International O&M Manual Hydro-Sludge™ Screen •Page 2.0-1
March 30, 2020
General Information
Hydro-Sludge™ Screen General Information
Overview
The Hydro-Sludge™ Screen is a horizontal in-line coarse material separator, comprising of four principle zones;
inlet, screening, pressing (compacting) and discharge. The feed from the inlet, enters the center of the screening
zone, where the coarse material retained on the inner surface of the perforated screen, is transported to the
pressing zone and onwards to the discharge by an Archimedean screw. Compacted coarse material (screenings)
is discharged into a suitable container, by the action of a regulated retention cone, controlled by a pneumatic
system linked the varying drive load (torque) of the drive motor.
Safety Precautions
The purpose of this Operation & Maintenance Manual is to ensure all personnel working with the plant are aware
of the safe and correct way to carry out any work. The instructions and information given are as explicit as is
reasonably practicable, however, competency and expertise are necessary in the operation and maintenance of
the machine, and to ensure reliable operation it is strongly recommended that such work is undertaken by only
experienced and authorized personnel.
Throughout this manual will be used to highlight important warning notes.
Before carrying out any inspection, maintenance, repairs, overhauls or commissioning on the Hydro-Sludge™
Screen; this manual must be read in detail, and always ensure that the machine has been isolated from both its
control panel and the raw material feed, where necessary to ensure that accidental starting of the machine cannot
occur.
In addition to the above, full adherence with current health and safety rules, acts, laws and legislation must be
observed, along with specific site procedures.
The Hydro-Sludge™ Screen must not be operated without operational protection devices and
covers in place.
The Hydro-Sludge™ Screen must not be used if any alterations have been carried out to the
machine which affect its normal operational behaviour, and more importantly any alterations which
affect the safe operation of the machine.
If any of the above are observed, isolate the machine and inform the person or department responsible for the
machine.
On completion of any maintenance, all guards/covers must be properly refitted before power and feed are
reinstated and the machine restarted.
This manual should be read in conjunction with the Electrical and Pneumatic Control Panel Operation &
Maintenance Manual, associated with the Hydro-Sludge™ Screen.
The Hydro-Sludge™ Screen warranty will be invalidated, and Hydro cannot be held responsible for product
failure, if:
The machine is used for work for which it was not designed or intended.

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The Hydro-Sludge™ Screen is used to process sludge outside the criterion detailed in the Technical Data,
see section 9.0, p17 ).
Damage is caused to the machine as a result of; operation and maintenance not being carried out to the
details of this manual, or operation without the required safety devices.
Any modifications or changes are carried out to the machine that affects its normal operation.
Known Hazards and Risks
The machine, when operated by fully trained personnel, is an exceptionally safe piece of equipment, which if
operated correctly and maintained as identified in this manual, should provide many years of service.
However, the following are areas that must be given due consideration at all times during the operation,
inspection and maintenance of the machine:
Moving Parts - These can become accessible when covers or guards are removed for inspection of the
operation of the machine.
Danger of cutting, shearing and crushing. Danger of contamination from the materials that have been
processed.
Pneumatic System - Compressed air must never be directed at uncovered skin, eyes, ears or any part of
the body.
Danger of grit/dirt being forced into the body under pressure of the compressed air.
Junction Boxes - Low voltage live terminals, will be accessible if the electrical supply is not isolated before
opening the covers.
Danger of electrocution.
Gearbox - Damage could be sustained to the gearbox housing if the breather or vent is not fitted, or is
blocked.
Danger of gearbox body bursting/cracking. Danger of contamination from oil spillage.
Central Joint - If the machine requires splitting in half for maintenance or inspection, then a small amount
of effluent could escape upon separation of the two halves.
Danger of contamination from materials being processed.
Avoid the above by:
Ensuring that only fully trained personnel operate, inspect and maintain the machine.
Ensure power and feeds are isolated.
Always wear appropriate personal protective equipment.
Wash your hands and any other parts of the body that come into contact with sludge as soon as
convenient.
Always observe all safety rules, acts and regulations when dealing with the machine.
The electrical devices fitted to the standard Hydro-Sludge™ Screen are not intrinsically safe, i.e.
they are not explosion proof, and therefore must not be installed in hazardous locations.

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March 30, 2020
General Notes
Description of Operation
The machine is designed to process solid matter from fluids of higher viscosities i.e. sludge and comprises of four
main zones, as shown in Figure 3.a.
Figure 3.a: Functional Diagram
The main elements of the machine are the geared motor, integral screws, pre-determined perforated mesh
screens and retention cone, which regulates the discharge of the screenings.
There are two interfaced screws driven by an efficient geared motor arrangement, sized to accommodate the full
range of typical sludge’s expected, such that the full capacity of the motor is never exceeded. The first screw is
the screening zone, the other is the pressing zone.
As the feed is fed into the inlet of the machine, the screen starts to blind and the pressure inside the machine
increases. This pressure is detected by the inlet pressure transducer, which starts the machine, once the start
pressure set point is met (default - 0.1 bar). As the Archimedean type screening zone screw conveys the fluid,
particles larger than the chosen perforation of the mesh screen are retained. These are then conveyed by the
screw to the pressing zone. Free fluids passing through the mesh are discharged from the machine via a flanged
outlet connection fitted at the bottom of the machine in the screening zone body and progress onto the next
process.
The remaining material is compacted in the continual action of the pressing zone screw. The discharge of solid
matter is controlled by the retention cone situated at the end of the pressing zone. The retention cone initially
serves as a seal inside of the machine, until the screenings plug is formed. The retaining force of the cone is
continually adjusted by a relationship between the drive load of the motor and control pressure. As the plug
increases, the drive load increases and the corresponding control pressure (cone opening pressure) is increased,
balancing the cylinder pressure (cone closing pressure), allowing the screenings plug to push back the cone and
screenings to be discharged.
The discharged plug is gradually broken up against the retention cone, by the continual action of the cone
opening and closing against the nozzle. These pieces are then normally collected in a skip or enclosed bagging
Feed
Screened
Outlet
Screenings
Discharge
Screening Zone
Pressing Zone
Screenings
Outlet
Inlet
Inlet
Pressure
Transducer
Outlet
Pressure
Gauge
Moisture
Sensor
Center
Flange
Retention
Cone
Pneumatic
Cylinders
Screenings
Plug

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unit, situated under the machine for final disposal. If a failure occurs and the plug in lost, resulting in a sludge
break-through, the moisture sensor inside the discharge box will detect this and immediately stop the machine,
and so long as the correct interlocks are in place, then the feed should also be stopped.
Once the pressure at the inlet drops below the set point, the machine continues to run for a preset run-on time
(default - 2 minutes) to clear the machine. If the pressure rises above the set point, the machine will run as normal
and the run-on timer is reset.
As a guide to the normal operation of the machine:
The drive load of the machine at idle (i.e. No load, feed or plug) should be 20-25%, depending on the
individual machine characteristics.
The optimal inlet pressure is 1 - 1.2 bar (14.7 - 17.4 psi) with trip point at 1.5 bar (21.8 psi), however the
machine will operate as long as a pressure greater that the start pressure set point is maintained.
The pressure differential between the inlet and outlet should be between 0 and 0.4 bar (0 to 5.8 psi).
A major benefit of this machine is that there is no requirement for washing or back flushing of the machine.
The degree of separation of solid matter is a condition of the selection of the screen perforation size (available in
2 - 10 mm), which also influences the quantity of screenings produced.
It is our experience with municipal sewerage sludge that an average of approximately ½ gallon of screenings is
produced per cubic yard of feed sludge.
With regard to the Hydro-Sludge™ Screen’s location in the process, Figure 3.b shows a typical arrangement. The
feed can either be pumped, fed by a tanker truck, or both. The addition of a reception tank can provide benefits in
balancing the flow to the machine, for both consistency and flow rate.
The requirement for the installation of a stone trap prior to the machine is dependent on the
specific site conditions. However, where fluid is likely to contain grit and/or stones, it is strongly
recommended.
The screened outlet is recommended as an open gravity discharge, however an elevated discharge of up to 3
yards is acceptable. However, the start pressure must be adjusted to overcome the back pressure.
Figure 3.b: Typical Hydro-Sludge™ Screen Process

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Capacity of the Machine
The throughput of the machine depends upon many factors such as: -
The viscosity of the fluid being processed.
The flow rate at which the fluid is being fed to the machine.
The size, shape and quantity of the solid matter (screenings load) within the fluid to be processed.
The perforation size of the machine screens.
The condition of the machine (i.e. setting up and maintenance of the machine).
The capacity data is given in section 9.0 - Technical Data, and provides a guide to the possible throughputs.
Optimum Operating Conditions
The following are conditions that assist the Hydro-Sludge™ Screen to perform at its optimum, when treating
sludge:
Where the feed is pumped, we recommend that the pumps are selected from the centrifugal range, using
a non-clogging, vortex impeller.
Sludge should be limited to a maximum of 6% dry solids concentration.
Normal inlet operating pressure should be kept at between 1 and 1.2 Bar (14.5 – 17.4 psi).
Outlet pressure is variable depending upon feed pressure, sludge thickness, screen perforation size and
outlet pipework configuration, with typical pressure loss through the machine up to 0.5bar.
Where applicable, the machine should be protected against freezing conditions. This may involve heat
tracing and lagging.
The clearance between the screening zone screw and screen should be as small as possible, (almost
touching). (Note -This will have been set during factory testing before shipment or at commissioning)
Environmental Issues
At the end of the machine’s serviceable life, most of its components can be dismantled and recycled.
Always ensure that current laws, regulations, legislation and directives for disposal are adhered to.
When dismantling the machine for disposal, take care to identify the materials correctly.
Table 3.a provides a guide to the key components materials of a standard machine.

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March 30, 2020
Table 3.a: Hydro-Sludge™ Screen Materials
Material Parts
Stainless Steel
Screening Zone and Pressing Zone Screens
Pressing Zone Screw, except for keyed stub shaft
Inspection lid hinges on the screenings discharge cover
Adjusters and lock nuts for the wheels on the Pressing Zone body
Pressure Transducer adapters
Clutch Rod
Turning piece
Discharge chute
Intermediate ring
Gearbox Collar
All nuts, bolts and washers
Mild steel
Screening Zone and Pressing Zone bodies and supports
Screening Zone Screw flights and main shaft
Pressing Zone Screw keyed stub shaft
Screening discharge cover
Inlet box access opening covers
Inlet box access plate
Screw shaft covers, either end of the machine
Intermediate Flange
Cast iron
Inlet and Discharge boxes
Nozzle inside Discharge box
Bearing Housing and cover
Gearbox housing
Aluminium
Pneumatic cylinder casings
Pneumatic cylinder adaptors
Motor body
Cladding for the trace heating & lagging
Bronze / Brass
Stuffing box follower
Thrust shim
Cutting Ring
Lubrication ring
Lock Nuts on Pressing Zone Screw
Plastics / Rubbers
Screening discharge inspection cover handle
Retention cone
Roller wheels
Pneumatic air lines and coils
O-Rings and gaskets
Oil Gearbox, Cyclo and Helical sections
Other grease / lubricants Grease pipes to retention cone and gland packing seal.

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Section 1
Installation / Removal of the Hydro-Sludge™ Screen
Installation
Following delivery, after careful removal of any packaging materials, the machine should be checked for damage
and prior to installation, Hydro International must be notified immediately if any damage is found.
To install a machine for the first time or following repair, the following instructions must be followed:
•Lift the machine into position using appropriate and certified lifting equipment, such as a crane, ensuring
that the machine is lifted using its lifting lugs. See Figure 4.a.
Lifting from any other position, or the use of straps around the body, could result in damage being
caused to the machine and / or risk of injury to personnel. If the machine is heat traced and lagged,
care should be taken not to dent or damage it.
•Once in position, ensure that the machine is upright and level. Bolt the screening zone section of the
machine to its supporting medium, i.e. steel platform or concrete slab, via the two fabricated supporting
brackets.
•Adjust the four wheeled support legs to align the longitudinal axis of the screening and pressing zones
using the nuts on the spindles.
•Connect a drain hose, if required, to the 2” hose tail located on the underside of the inlet casting.
•Connect feed and discharge pipework to inlet and outlet flanged connections on the machine.
•If applicable, install any screenings discharge chute, ensuring that a gap is left between the machine chute
fixed to the underside of the discharge box and the main discharge chute, to allow the machine to be easily
split for maintenance.
•Position the screenings collection system below the discharge chute.
•Carryout the required electrical cabling and connections to the machine device (i.e. motor, pressure
transducer, moisture sensor, discharge cover switch and trace heating) where fitted.
•Connect the pneumatic air supply pipes to the ports of the coils from the pneumatic cylinders.
•Once the installation is complete and prior to the commissioning, ensure that the Hydro-Sludge™ Screen is
protected from freezing conditions.
Removal
If a machine must be removed for repair, the following instructions must be followed:
•Isolate and lock off all feeds and power supplies.
•Disconnect all cables, pipework and pneumatics.
•Unbolt the screening zone section of the machine from its supporting medium (i.e. steel platform or
concrete slab) at the two fabricated supporting brackets.
•Lift the machine from its position using appropriate and certified lifting equipment, ensuring that the
machine is lifted using its lifting lugs. See Figure 4.a.
Lifting from any other position, or the use of straps around the body, could result in damage being
caused to the machine and / or risk of injury to personnel. If the machine is heat traced and lagged,
care should be taken not to dent or damage it.

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ALWAYS USE THE MACHINE LIFTING LUGS TO LIFT THE MACHINE.
Figure 4.c: Lifting Arrangement
ALWAYS ENSURE THAT THE HYDRO-SLUDGE™ SCREEN IS BALANCED WHEN LIFTING.
30° - 90°
Note! The angle between the lifting chains
/ straps should be between 30° & 90°.
It is important that when larger angles are
used that the chains / straps have been
correctly tested before use.

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Section 2
Hydro-Sludge™ Screen Start-Up
Where commissioning is not part of the scope of supply for the machine or where the equipment has been re-
installed, the following instructions must be followed:
Before starting any commissioning, check that the machine and panel have been correctly installed
and securely fixed into place.
The site commissioning should be broken down into dry and wet commissioning.
Dry Commissioning
Checks to be carried out before electrical power is applied
•Check all the Hydro-Sludge™ Screen and control panel wiring and air line connections are made.
•Check the Hydro-Sludge™ Screen rollers are set and tight, adjust as necessary.
•If the inlet box has a gland packing seal, check that a drain is connected to the hose tail on the underside of
the inlet box.
•Ensure that the inlet and outlet pipework is securely connected.
•Check that there is some sort of container below the discharge chute to collect screenings.
•Open the breather on the outlet pressure gauge.
•Check the power feed certificate for the supply.
Checks to be carried out following electrical power switch on to control panel
Do not allow the machine to run for longer than 5 minutes during dry testing.
•Check the power supply into the control panel.
•Switch on the panel isolator, check for successful boot up and select manual mode.
•Check that the compressor starts and charges the reservoir for to a cylinder pressure of about 3.5 bar (50
psi).
•Start machine in manual using the start button and check rotation of the motor in relation to directional
arrow on shaft cover. (Clockwise at the gearbox end)
•Check drive load is approx. 20-25%.
•Ensure that the machine stops in manual mode via the stop button and then restarts again.
•Operate the emergency stop switch on the panel. Check that the machine stops. Release the emergency
stop, reset the panel and start the machine.
•Operate the emergency stop switch adjacent to the machine (if applicable). Check that the machine stops.
Release the emergency stop, reset the panel, and start the machine.
•Open the screenings discharge hatch. Check that the machine stops. Close the screenings discharge
hatch, reset the panel, and start the machine.
•Switch the moisture probe override on. Using a wet cloth, wipe the moisture probe. The machine should
continue to run. Dry the moisture probe, reset the panel and start the machine.
•Switch the moisture probe override off. Using a wet cloth, wipe the moisture probe. Check to ensure that
the machine stops. Dry the moisture probe, reset the panel, and start the machine.
•Check the span of control air to ensure that the control and cylinder pressures are equal at maximum drive
load (default 80%).

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Wet Commissioning
•Set the machine to auto and start the sludge feed. Note - It is advantageous to have reasonably thick
sludge for commissioning as this helps produce a plug quickly.
•Check that the panel is monitoring pressure and the machine starts at set point (default 0.1 bar or 1.5 psi).
•Once the machine is full of sludge, stop the feed, recheck the drive load (approx. 20-25%) in manual and
adjust as necessary. Record drive load and amperage.
•Measure and record the position of the screw, dimensions Ls& Lp. Dimension sum should be same as
result for Factory Test.
•Restart the system. It is likely that some sludge will spray into the discharge box, as the plug is forming,
which may trip the machine. If this happens, the moisture detector should be switched to override during
the start-up operation and the panel reset. Once returned to normal operational mode, the moisture
detector override can be switched off.
•Make a record of the pressure values at both the inlet transducer and outlet gauge. The pressure
differential should be between 0-0.4 Bar (0-5.8 psi).
•Make a record of the drive load and amperage with sludge.
Note -Once the plug is formed, screenings will start to discharge. Initially they may be wet but will dry
with time, which could be up to several hours depending upon the type and condition of the sludge.
•
•If Gland Packing: Tighten stuffing box follower, until there is only a slight drip from the seal.
•If Mechanical Seal: Check that the mechanical seal has a good seal with no leaks.
•Stop the sludge feed and check that the inlet pressure drops below the set point and that the machine runs
on for the preset time (default 2 mins). If the pressure does not drop below the set point, check the outlet
pipework for static head and adjust to compensate. If the start pressure is adjusted, record the new setting.
•Start the sludge feed again and check that the machine starts, particularly if the set point was adjusted.
•If possible, induce an inlet pressure of over 1.5 bar and check that the machine trips. Then reset the panel.
Note - If there is no interlock between the machine and sludge feed, there is a risk of blowing out the plug.
•Continue running sludge through the machine to check the general operation.
•Carry out and record any necessary fine adjustments of the pneumatic panel (i.e. cylinder pressure, control
pressure span etc.).
Data Collection
The following is important data that should be recorded and entered onto the record data sheet, which can be
found in the appendix, section 11.2.2:
•Position of screw. (Ls/ Lp)
•Drive load and Amperage at idle. (No load, feed or plug)
•Pressure values and differential during processing
•Drive load and Amperage during processing. (Under Load, with feed and plug)
•Approximate sludge throughput in yd3/hr
This data will be the datum settings, which will eventually change during the machine’s working life.
It is therefore important to take further readings, recording them on the record data sheet, as this will indicate the
performance and condition of the machine, and whether any maintenance is required.
It would also be useful to record the following data to indicate performance of the machine.
•% dry solids of the sludge. (This will have to be laboratory measured from samples taken.)
•% dry solids of the screenings. (This will have to be laboratory measured from samples taken.)

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Section 3
Hydro-Sludge™ Screen Maintenance and Troubleshooting
Maintenance Schedule
The schedule for the key maintenance tasks, associated with the Hydro-Sludge™ Screen are shown in Table 6.a.
Before commencing any maintenance on the Hydro-Sludge™ Screen, always ensure that the
machine has been isolated from the electrical supply and feed supply, as appropriate, to ensure
that no accidental starting can occur.
Throughout this section of the manual, the various components of the Hydro-Sludge™ Screen are referred to by
item numbers, which can be found on the Spare Parts Lists and Drawing in the appendix, section 11.1.2.
Table 6.b: Maintenance Schedule
Activity
Weekly
Monthly
Quarterly
Semi
-
Annually
Annually
Grease discharge end - retention cone (see section 6.1.1, p2). ●
Grease inlet end - shaft seal (see section 6.1.3, p2). ●
Grease discharge end - bearings (see section 6.1.2, p2).
●
Grease inlet end - shaft lubrication (see section 6.1.4, p2).
●
Carryout screw adjustment (see section 6.4, p7).
●
Check moisture sensor (see section 4, p4).
●
Check gland seal packing (see section 6.2.2, p4).
●
Check wearing parts (see section 6.2.6, p5).
●
Check discharge cover safety limit switch (see section 6.2.3, p4).
●
Check pneumatic system (see section 6.2.4, p4)
●
Clean & inspect screening zone (see section 6.2.5, p5).
●
Check gearbox oil levels (see section 6.1.6, p2).
●
Carry out metal work checks (see section 6.2.7, p5). ●

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Clean & inspect pressing zone (see section 6.2.5, p5).
●
Clean & inspect all bearings (see section 6.1.5, p2).
●
The above scheduled is based on regular usage throughout an 8-hour day, 5 days a week. If the usage of the
machine is higher or the sludge content particularly coarse, then the frequency of the tasks should be increased
accordingly.
For maintenance details of the control panel, refer to the O&M for the control system.
Lubrication
The Hydro-Sludge™ Screen has four (4) grease nipples fitted to the external surface of the machine (see Figure
6.a, p 15) to facilitate easier maintenance. (For recommended grease types, see Table 6.b):
1.1.1 Discharge End - Retention Cone
A grease nipple is fitted at the discharge end of the machine, which provides grease to the retention cone and
shaft interface. This requires the application of four (4) strokes of a grease gun, once a week.
1.1.2 Discharge End - Bearings
A grease nipple is fitted at the discharge end of the machine into the bearing assembly of the pressing zone
screw. This requires the application of two (2) strokes of a grease gun, once a month.
1.1.3 Inlet End - Shaft Seal
A grease nipple is located at the bottom of the inlet chamber of the machine, which provides lubrication direct to
the shaft seal fitted in this location. This requires the application of six (6) strokes of a grease gun, once a week
1.1.4 Inlet End - Shaft Lubrication
A grease nipple is fitted to the gearbox joining plate and requires application of two (2) stokes of the grease gun,
once a month.
1.1.5 Bearings
The main bearings are filled with grease before shipment. However, all bearings should be cleaned, inspected,
and recharged with grease annually.
1.1.6 Gearbox
The gearbox has two oil compartments, one for the Buddybox, filled from the top (oil filler / air vent) and one for
the Cyclo portion, also filled from the top (oil filler / air vent).
An initial oil change after the first 500 hours is highly recommended.
Thereafter, all oil levels should be checked at least every 5000 hours.
The oil should be changed at a minimum interval of 10,000 hours.
For further information and details on the recommended types of oil, see Table 6.c, and for full details, including
oil viscosity class chart, refer to the Sumitomo Buddybox information in the appendix, section 11.3.1.

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Grease nipple locations
For reference, the units are usually filled with Shell Omala HD220, however refer to the Build Log to check
specifically.
Figure 6.d: Lubrication Points on the Hydro-Sludge™ Screen
Indicates that the grease nipples may be on the other side of the machine, depending on
the orientation.
Table 6.c: Recommended Grease Types
Manufacture Type of Grease
Shell Alvania R3
Alvania RA
BP Energrease LS3
Esso Beacon EP or 325
Total Multis Special 3
Mobil Mobilux EP3
Table 6.d: Recommended Types of Oil for the Gearbox
Manufacture Type of Grease
Shell Omala
BP Energol GR-XP
Castrol Alpha MW
Esso Spartan EP
Total Carter EP
Mobil Mobilgear
Gearbox oil
filler locations

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Inspections and Checks
There are many components to the Hydro-Sludge™ Screen that need to be checked and inspected regularly, as
detailed below:
1.1.7 Moisture Sensor
Once a month check the operation of the moisture sensor, item 47:
1. Ensure the machine is switched off and cannot be started accidentally and that the moisture override switch
is in the ‘Off’ position.
2. Clean the sensor front face and dry off.
3. Check the operation of the sensor by pressing a wet cloth against the sensor. The panel should display and
moisture fault and it should not be possible to start the machine from the control panel in either ‘Auto’ or
‘Manual’ mode.
4. Return the Hydro-Sludge™ Screen to normal operation.
1.1.8 Gland Seal Packing
Once a month the seal packing, item 56, must be checked:
•Ensure that the machine is switched off and cannot be started accidentally.
•Remove both access covers, items 260, either side of the inlet casting.
Note - If casting contains a significant amount of sludge, check drain water discharge hose for blockages.
•Adjust both M12 Nuts, items 151, to tighten stuffing box follower, item 50, onto the gland packing, there
should be a very slight dripping from the gland, to ensure it remains moist.
•If no further adjustment is possible, the gland packing will need to be replaced. Back off the stuffing box
follower, item 50, remove and the old packing and replace with new, item 56, then refit the stuffing box
follower.
•Refit access covers, item 260.
•Return the Hydro-Sludge™ Screen to normal operation.
1.1.9 Discharge Cover Safety Limit Switch
Once a month check the operation of the limit switch, item 27:
•Open the discharge cover, item 256. The panel should display a fault and prevent operation of the
machine.
•Inspect the switch, checking that there is no damage and that the opening for the actuator, item 28, is clear
and clean.
•Close the discharge cover and reset the panel fault.
1.1.10 Pneumatic System
Once a month the operation and condition of the Hydro-Sludge™ Screen side of the pneumatic system, i.e. the
pneumatic cylinders, items 25, the pneumatic tubing, item 286 and coils, items 194 & 195 must be checked:
•Check the pneumatic tubing and coils are free from damage and there are no air leaks.
•Operate the cone reversal system on the panel.
•Open the discharge cover, item 256 and check that the retention cone, item 22, is fully back.

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•Close the discharge cover, reset the panel, and turn off the cone reversal.
•Open the discharge cover and check that the retention cone is fully home into the nozzle, item 157.
1.1.11 Screening and Pressing Zones
The machine should be split and opened once a month (see section 6.5), with the screening zone cleaned and
inspected for damage and wear, including the screening zone screw and screen (see section 6.6). Then every six
months the pressing zone should also be cleaned and inspected for damage and wear, including the pressing
screw and screen (see section 6.6).
1.1.12 Other Wearing Parts
There are many smaller wearing parts in the Hydro-Sludge™ Screen, which should be checked and inspected
once a month, as part of the general maintenance:
Thrust Shim, item 1 - Check condition whilst machine is split for screening zone checks.
Intermediate Flange, item 21 - Check condition whilst machine is split for screening zone checks.
Cutting Ring, item 2 - Check condition when the retention cone is reversed to check pneumatic system.
Retention Cone, item 22 - Check condition, particularly the sloped leading face, when reversed to check
pneumatic system.
1.1.13 Metal work protection
1.1.13.1 Hydro-Sludge™ Screen
Every 6 months the Hydro-Sludge™ Screen external and where possible internal paintwork should also be
inspected for corrosion.
Any areas found to be affected, should be wire brushed and repainted.
1.1.13.2 Platform
If the scope of supply for the installation includes a platform on which the Hydro-Sludge™ Screen is mounted, this
also requires regular inspection.
All platform steelwork is hot dipped galvanized to BS EN ISO 1461 and needs to be examined every 6 months for
corrosion.
Any areas found to be affected, should be wire brushed and cold galvanized.

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Screw Measurement Check
Before carrying out the screw adjustment or splitting the machine, as detailed in the following sections, it is
advisable to carry out a screw measurement control check (see Figure 6.b for an overview), to obtain the
individual machine Ls& Lpsum, so the machine can be reassembled with the confidence of knowing the screws
are correctly pulled together and it enables the wear of the screening zone screw to be assessed:
Figure 6.e: Screw Measurement Control Check Overview Drawing
Figure 6.f: LsMeasurement
Figure 6.g: LpMeasurement
•Ensure that the machine is switched off and cannot be started accidentally.
•Remove both screw covers, items 240 and 152 to expose the screw ends.
•Measure Lsand Lpas shown. The sum of these dimensions should always be constant for a set of screws
and screens in a machine, i.e. approx. 40-55 mm (1.6-2.2 in.).
Note - This will also serve as a check to ensure that both screws are bolted tightly together.
•When measuring Ls always ensure that the gearbox mounting collar assembly, item 358 is hard up against
the gearbox. When measuring Lpthe two lock nuts, items 15, must be locked together tightly against
distance bush, item 76.
•
Note - A spare screening zone screw & screen should be ordered once Lp = 40 mm (1.6 in.), as maximum
adjustment is approximately 50mm (2.0 in.) and delivery time can be up to 8 weeks.
L
p
L
s
L
s
Lp

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Adjustments for Wear of Screening Zone Screw and Screens
1.1.14 General
To keep the machine in optimum operational condition, it is important to keep the clearance between the
screening zone screw and screen at a minimum (almost touching). This should prevent the screen from becoming
blocked and thus keep the machine operating correctly.
As the screw and screen becomes worn with use, the clearance increases, and the machine performance is
reduced. This will be noticed by either a reduction in throughput quantity and screenings discharge volume and/or
by an increase in inlet pressure, as observed on the control panel.
The clearance between the two is adjusted by drawing the screw into the screen, along its longitudinal axis, using
the adjusting nuts fitted to the pressing zone screw, which is attached to the screening zone screw via a tie rod.
When Lp= 50 mm (2.0 in.), no further adjustment of the screw will be possible, and it will require replacing with a
new screw and we would recommend changing the screen as well.
1.1.15 Discharge Plug Clearance
Prior to any adjustment of the screws, the compacted screenings (plug) at the discharge needs to be removed.
This is to ensure that there is no restriction of the screw movement and that the drive load is at its minimum, no
load point.
The plug is removed as follows: -
•Isolate the inlet and outlet for the machine, to ensure there is no flow to the machine.
•Move the Selector Switch from “Auto” to “Rev” and the retention cone will reverse to allow access to the
plug.
•Run the Hydro-Sludge™ Screen, using the Start / Stop buttons for 2-3 minutes to drive the plug forward.
•Stop the Hydro-Sludge™ Screen.
•Open the discharge cover and dig out as much as possible of the plug.
•Close the discharge cover and reset the machine.
•Repeat 3 - 6 until no more plug is driven forward and the end of the discharge it clear.
•Return the Hydro-Sludge™ Screen to ‘Auto’ and re-instate the feed.
1.1.16 Screw to Screen Clearance Adjustment
To carryout adjustment of the screw to screen clearance, follow the steps below: -
•Clear the discharge plug, see 6.4.2.
•Ensure all incoming flows are Isolated.
•Run the Hydro-Sludge™ Screen in ‘Manual’ Mode for up to 2 - 3 minutes until the drive load of the
machine, as observed on the control panel, remains fairly constant. Take a note of this reading. If the
reading is less than the optimum of 20-25 %, adjustment is required.
•Switch off the Hydro-Sludge™ Screen and isolate it against accidental operation.
•Remove the screw covers items 240 and 256 and unscrew the outermost lock nut, item 15 on the pressing
zone screw, using the adjusting bars, items 216.
•Loosen grub screw, item 204 in the gearbox collar, item 358.

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•Tighten the innermost lock nut, item 15, ¼ of a turn to draw the screws towards the discharge end of the
machine. Each 1mm increase in Lpreduces the clearance between the screening zone screw and screen
by 0.10mm on the diameter. Therefore, 50mm (~2 in.) on Lpequates to 5mm (~3/16”) change in diameter.
•Start the machine in ‘Manual’ mode and observe the drive load on the control panel. If this reading remains
constant within the optimum range, then adjustment is complete. Otherwise, repeat the adjustment from
step 4 above.
The screw must never be adjusted to the extent that grinding noises can be heard from within the
machine, or the drive load increased grossly from optimum, otherwise the screw and screen will
become prematurely damaged. This would also result in the control pressure of the retention
cone being incorrectly set by the automatic control system.
•Stop the machine and tighten the outermost lock nut against the innermost lock nut, to prevent any
movement of the nuts.
•Measure Lsand Lpagain and record the measurements in the record data sheet (see appendix, section
11.2.2).
•Ensure the gearbox collar, item 385 is hard up against the gearbox, then tighten grub screw, item 204.
•Start the machine in ‘Manual’ mode and observe the drive load on the control panel and check that the
reading has not changed and is still within the optimum range. If the reading has dropped, repeat
adjustment from step 4. If the reading has increased, slightly loosen the lock nuts, items 15, and run the
machine for up to 5 mins, until the drive load returns to the optimum range; then check the lock nuts are
tight and ensure the gearbox collar, item 385 is hard up against the gearbox.
•Refit the screw covers, items 240 and 256.
•Reset the Hydro-Sludge™ Screen and feed supply back into ‘Auto’ mode.
•The machine is now available for use.
Splitting the Machine
For various maintenance purposes, cleaning, inspection and spares replacement, it is necessary to start by
splitting the Hydro-Sludge™ Screen to provide access to the inside of the machine, see Figure 6.e below for
reference.
•Isolate the inlet and outlet for the machine, to ensure there is no flow to the machine.
•Switch off the Hydro-Sludge™ Screen and isolate it against accidental operation.
•Remove screw covers items 240 and 256.
•Measure Lsand Lpand make a note in the record data sheet (see appendix, section 11.2.2). This is
important as these measurements are used to check that the machine has been re-assembled correctly.
•Loosen the lock nuts, items 15, using the adjusting bars, items 216.
•Unscrew and remove the three M12 fixings, item 145, that bolt the halves of the machine together.
•Unscrew the grub screw, item 204, in the turning piece, item 10.
•Using an adjusting bar located into turning piece, item 10, unscrew in a clockwise direction, to release the
clutch rod, item 8 from the pressing zone screw, until the machine halves separate.
The clutch rod has a left-handed thread.
•As the pressing zone is located on casters, it can now be disconnected and moved aside, providing access
to both the screening and pressing zones.

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Figure 6.h: Split Hydro-Sludge™ Screen
Screws and Screens Removal.
1.1.17 Removal of Screening Zone Screen.
•Having split the machine as described in section 6.5.
Unscrew the ½” BSP plug, item 150, fitted to the inlet
casting. This provides access to the screening zone screen
flange, to assist in removal of the screen.
•Insert a bar through the exposed hole and tap the bar gently
to dislodge the flange of the screen from its locating lugs
within the body of the machine.
•The screen can now be manually removed from the
machine.
Note - Always clean and inspect the screen before re-
assembly.
1.1.18 Removal of the Screening Zone Screw.
•Having removed the screening zone screen as described in section 6.6.1. Remove turning piece, item 10,
from the drive shaft, by unscrewing the M12 securing screw, item 205.
•Remove the grub screw, item 204 from the gearbox collar, item 358, and withdraw the collar from the drive
shaft.
•Unscrew and back off the stuffing box follower, items 151 and 50, to release the gland packing.
•Working from the middle of the machine, remove clutching rod, item 8, from the screw.
•Carefully withdraw the screening zone screw from the body of the machine, taking care as the diameter
varying shaft sections pass through the stuffing box.
Figure 6.f: Split Hydro-Sludge™ Screen -
Screening Zone Section

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Removal of Pressing Zone Screw.
Note - Due to the nature and action of the
machine some solid matter will remain within
the screw and screen area of the pressing
zone. In some instances, it may be
necessary to remove both the screw and
screen together and separate them once out
of the machine.
•Having split the machine as described in
section 6.5. Unscrew both lock nuts, items
15, from the screw shaft and remove the
distance bush, item 76.
•From the center of the machine, carefully
withdraw the screw from the body of the
machine, taking care as the diameter
varying shaft sections pass through the
bearings, within the bearing housing, item
258. Also protect the threaded shaft section
of the screw from damage and take care not
to lose the cutting ring, item 2 from the front of the retention cone, item 22.
1.1.19 Removal of the Pressing Zone Screen.
It is important never to remove the screen before the screw, as the screen helps to support the
screw as it is removed from the machine.
•Having removed the pressing zone screw as described in section 6.6.3. Remove the intermediate flange,
item 21, together with the thrust shim, item 1, by unscrewing the two M8 countersunk fixings, items 139,
which secure it in place.
•Unscrew the three M8 countersunk fixings, items 140, holding the pressing zone screen to the machine
body.
•Inset the two screen removal tee handles, items 217, into the screen flange and pull the screen from the
body. The screen has a support cage welded to the back half of the screen, which must be aligned with
slots in the body of the machine to fully remove it.
Note - Always clean and inspect the screen before re-assembling it.
Re-assembly of Screens and Screws
1.1.20 Re-assembly of Pressing Zone Screen.
•Working from the center of the machine, place the screen into the body, with the ‘V’ cut out in the flange
uppermost and the bars on the cage of the screen aligned with the slots in the body flange. Carefully slide
the screen into the machine, pushing it back until the flange and cage lugs locate into the back-body flange
of the machine. (Assistance may be required to locate the screen, from inside the discharge box.)
•Refit the three M8 countersunk fixings, items 140, to secure the screen to the body.
•Check the condition of the O-rings, items 39, in the intermediate flange, item 21, and replace if necessary.
•Refit the intermediate flange and secure using two M8 countersunk fixings, items 139.
Figure 6.g: Split Hydro-Sludge™ Screen
Pressing Zone Section