After use all of the solid material and liquid solutions should be emptied from the equipment before flushing the process pipework with clean water. Fill the Fresh Solvent Tank with clean water then operate the three stages of the process with the pumps at maximum speed to flush the system. Operation with the water at elevated temperature will be beneficial (set point on each PID controller at maximum). If the equipment will be operated within a few days of commissioning then the pipework should remain filled with de-ionised water to prevent deterioration of the electrodes inside the conductivity probes. After cleaning, fill the Solvent tank with de- ionised water then pump this through the system to leave the probes filled.
If the equipment will not be operated for a longer period then the conductivity probes should be removed from the pipework, flushed with de-ionised water then air-dried to prevent deterioration of the electrodes inside the probes.
After prolonged use it may be necessary to flush the system with a weak acid to remove any build up of the salt in the pipework etc. Refer to the Routine Maintenance section for further details if this is necessary.
Periodically it will be necessary to clean the Feeder and Extractor Cell. Details of the procedure for dismantling these components is given below. The general procedure for cleaning the equipment is to disassemble the parts which need cleaning,
removing any electrical assemblies and then to wiping the non electrical parts with a cloth soaked in warm soapy water (abrasive cleaners and volatile solvents should not be used). Note that when cleaning the equipment operators should avoid contact with the chemicals used and if necessary should wear protective gloves.
1. Cleaning of the extractor assembly:
a. To prevent damage to the sprinkler bars remove the quick release fitting from the end of each sprinkler bar (push the grey collar against the body of the fitting while pulling the fitting).
b. Unclamp the spray nozzle at the rear of the extractor, raise and rotate the rigid tube so that the tip of the nozzle is clear of the rotor.
c. Disconnect the electrical cable to the feeder from the socket on the underside of the console.
d. Remove the feeder by unscrewing the thumbscrews that secure it to the frame. Carefully tip any remaining solid carrier into a suitable container. e. Disconnect the electrical cable to the top of the central hub on the extraction
cell from the socket on the underside of the electrical console.
f. Remove the top of the extractor (including the hub and rotor as a complete assembly) from the base by unscrewing the two fixing screws (large thumb nuts) on top of the hub. The hub / rotor will simply lift away from the base revealing the mesh that allows the solvent to drain into the troughs underneath.
g. Carefully wipe the rotor with a damp cloth soaked in warm soapy water to remove any contamination.
h. With the hub / rotor removed the mesh which supports the solid carrier can be cleaned using warm soapy water Ensure that the central recess for the hub of the rotor is clear of any solid particles.
i. The collection troughs can usually be cleaned adequately by pouring warm soapy water through the mesh from above. However, if contamination is severe, the mesh can be removed to gain acces to the troughs for more thorough cleaning. The mesh should be lifted from the recess in the base, starting at one end and taking care not to distort it. After cleaning, the troughs and mesh should be dried using a soft cloth then reassembled by pressing the mesh into the recess, again taking care not to distort the mesh. When correctly assembled the mesh should be flush with the surrounding PVC base.
j. While the feeder / extractor hub are removed the frame can be cleaned to remove any dust or spillage using a damp cloth.
Operation
k. After cleaning, the extractor should be dried with a soft cloth and reassembled as follows:
Locate the central hub in the central recess of the base and rotate the hub until the dowel pin locates in the hole. Pass the two fixing screws through the two holes in the top of the hub and tighten the screws to secure the hub to the base. Reconnect the electrical cable to the base of the console. Refit the feeder to the frame using the thumbscrews.
l. Reposition the spray nozzle with the tip of the nozzle inside the cells but clear of the baffles.
m. Reconnect the flexible tubing to the spray bars on the extraction cell. Refer to Figure 1 and 3 in the equipment diagrams for details of the connections of the flexible tubing/sprinkler bars to the extractor. 2. Cleaning of Spiral Conveyor Assembly
a. Cleaning of the feeder will not usually be necessary when using the porous polymer pellets supplied by Armfield. However, after prolonged use or in unusual circumstances cleaning of the spiral conveyor and hopper will be necessary. Remove any remaining material from the hopper by running the conveyor or by tipping the material into a suitable container after removing the assembly from the frame by unscrewing the thumbscrews.
b. Detach the drive motor from the rest of the assembly by undoing the four caphead screws which secure the motor to the hopper. Pull the motor away from the hopper to separate the link between the motor and the spiral. Remove the drive coupling from the end of the spiral (where the motor was fitted) by unscrewing the grub screw that retains the coupling.
c. Having removed the motor and drive coupling undo the three thumb nuts on the other end of the tube containing the spiral and disassemble the remainder of the conveyor.
d. After cleaning with warm water, the components of the conveyor can be dried with a soft cloth and then reassembled. Assembly of the components is simply the reverse of the disassembly.