Attachment_5_-_New_WSR_-_MU_Process_Description.pdf

Attachment 5 Page 1 of 5 Pages

Attachment 5 Wastewater Pretreatment Plant (WWPP) Chemical Treatment Process

New Wiping Solution Recycling – Make-up Plant (WSRP)

PROCESS DESCRIPTION: The waste solution coming from the wiping processes on the intaglio presses is conveyed to the storage tank TK101, in which the low analog level LVA101L activates the stirrer ST101 and the working analog level LVA101W1 activates the screw pump PMV101, which transfers the effluent to the process tank TK102 via pneumatic ball valve PVC101A until reaching the working level LVA102W2.

The flow rate of all the screw pumps can be manually adjusted by means of the relevant hand-wheel. Analog level controls can be adjusted by the operator via touch screen.

In case of maintenance on the recycling section the effluent can be conveyed to the treatment tank TK403 via pneumatic ball valve PVC101B. Pneumatic valves are provided with an actuator, operated by the corresponding pilot solenoid valves PSV, and with a proximity switch to indicate their status (open/closed).

The storage tank TK101 is connected by overflow to the emergency tanks TK100- 100A, where the waste solution can be stored in case of maintenance and then pumped to the treatment section (tank TK403) to be disposed of.

The effluent flow rate to the process tank TK102 is read by the flow meter FM101.

The manual ball valve HV101 can be closed to intercept the circuit in case of maintenance; when in closed position, a proximity switch gives a signal which prevents the screw pump from starting.

The piston metering pump PD102 doses the reagent Dalsep directly from its supply drum and proportionally to the flow rate of waste solution via counter pressure valve VC102; the flow rate of reagent is read by the flow meter FM102R2. The safety valve 735 intervenes activating a by-pass in case of overpressure in the feeding pipe and an alarm is activated by the mentioned flow meter.

In the process tank TK102 the low level LVA102L activates the stirrer ST102, while the working level LVA102W1 activates the screw pumps PMV102A-B-C, which feed the decanters D104A-B-C via pneumatic ball valves PVC102A-B-C respectively.

Each pump can be activated only when the corresponding pneumatic ball valve installed on suction and/or delivery pipe is open (signal from proximity switch).

The high level LVA102H gives an alarm, like the mechanical overflow level LVM102.

Each flow rate to the decanters, read by the flow meters FM102A-B-C, is adjusted at about one third of the nominal capacity of the plant.

The maximum admissible flow rate for each decanter is 5000 l/h; the effective flow rate is to be adjusted on the basis of the real plant throughput.

Moreover each decanter is provided with 2 manual valves on its side in order to be able to evaluate the level of the deposit and the efficiency of removal of the concentrate.

The manual ball valves HV102A-B-C can be closed to intercept the corresponding circuits in case of maintenance: when in closed position, a proximity switch gives a signal to prevent the relevant screw pumps to start.

In each decanter the supernatant overflows to the clarified solution treatment tank TK201 to the filtration stage.

The analog low level LVA201L activates the stirrer ST201, the analog level LVA201W1 activates the pneumatic membrane pumps PP101 and PP201 (operating by turn), the analog level LVA2201W2 stops the screw pumps feeding the decanters and

Attachment 5 Page 2 of 5 Pages the analog high level LVA201H gives an alarm, like the mechanical overflow control

LVM201.

The filter-aid perlite is conveyed to the tank TK201, proportionally to the amount of clarified solution from the decanters (i.e. approx. 90% of the total volume of waste), by means of the motorized screw conveyor 232, whose speed is adjustable by the field inverter IN232 for flow rate adjustment. The perlite addition is made by motorized screw conveyor, inverter controlled, for which the frequency (or the rpm value) is proportionally linked to the flow rate of product.

The perlite, entering in the tank through the pneumatic gate valve VL233, is stored in the stainless steel hopper TK202, equipped with the dust remover SC495, installed on top of it. This device is a self-cleaning filter connected to the blower 294.

The two automatic filter presses for recycling FP105 and FP205 operate by turn, so as to ensure the continuity of the production: when one of the filter reaches the end of cycle, meaning that its internal pressure reaches the saturation value (3-4 bars, adjustable via touch screen), and needs to be opened by the operator for sludge removal, the other can be started without affecting the process.

The pneumatic membrane pump PP101 (PP201), which feeds the filter press FP105 (FP205) via pneumatic ball valve PVC116 (PVC216), is actuated by the compressed air line through the 3-way proportional valve PV107 (PV207) by a feedback control loop based on the pressure value inside the filter press, as measured by the pressure transducer PS147 (PS247), installed together with the pressure gauge 146

(246) on the expansion vessel 145 (245).

A pressure regulator 802, a pressure gauge 108 (208) and a safety valve 111 (211) are also provided on the compressed air feeding line.

The filter press FP105 (FP205) is equipped with 50 PP filter plates by 600x600 mm and relevant PP filtering cloths.

It is also provided with a hydraulic power unit FP141 (FP241) to compact the plates at the required pressure as well as to open the filter press once reached the end of cycle: it also has a motorised plate shifting system FP142 (FP242) for sludge removal.

The sludge in form of cakes falls in proper containers placed beneath the filter frame.

Before operating in production the automatic stand-by cycle makes the effluent circulate back to the feeding tank TK201 via pneumatic membrane valve PVO116B (PVO216B) for a preset time. This represents the filtration warm-up (maximum 5 minutes) which properly distributes the pressure on the plate surface and removes impurities from the cloths before starting the production.

Then the pneumatic membrane valve PVO116A (PVO116A) opens and the filtered effluent is sent to the recycled solution storage tank TK301 until reaching the analog level control LVA301W2.

After reaching the pressure setpoint for the end of cycle, the system automatically activates a sludge dehydration phase by means of compressed air via pneumatic ball valve PVC116C (PVC216C); during this phase the liquid is sent back to tank TK201.

The recovered solution contained in the tank TK301 is pumped to the mixing tank TK315 by centrifugal pump PMC301, activated by the analog level LVA301L and stopped by the analog level LVA315W2.

The recovered solution is also used for the washing of the pipes and the screw pumps which intake from the bottom of the decanters, i.e. PMV104A-B-C, via the corresponding pneumatic ball valves PVC104LA-B-C. This phase is activated by the operator and the resulting liquid is sent to the treatment section (tank TK401).

The concentrate is also pumped from the bottom of the decanters by means of the mentioned pumps to the tank TK401 via pneumatic ball valves PVC104A-B-C.

Attachment 5 Page 3 of 5 Pages

The flow rate of concentrate from one decanter, e.g. D104A, read by the flow meter FM104A corresponds to 10% of the reading of the flow meter FM102A (in all the concentrate from the decanters indeed represents the 10% approx. of the total volume of waste solution).

The manual ball valves HV104A-B-C, installed on the delivery pipe of the screw pumps PMV104A-B-C, can be closed to intercept the corresponding circuits in case of maintenance: when in closed position, a proximity switch gives a signal to prevent the relevant screw pumps to start.

Before reaching the mixing tank TK315 the recovered solution passes through the safety filter FT560, equipped with three 20-inch cartridges by 5 microns mesh as well as with interception valves 510, discharge valves 511 and manometer 512.

When the pressure inside the filter reaches the setpoint adjusted on the pressure switch PS301 (maximum pressure 3 bars approx.), the cartridges need replacement, during which the stand-by filter is used.

The flow to the mixing tank is read by the flow meter FM301.

When in the tank TK315 the recovered solution is integrated with soft water from tank TK601 and with caustic soda solution and castor oil from the corresponding dosing lines.

In particular, below the analog level LVA315W1 the system automatically provides for fresh wiping solution, while between LVA315W1 until LVA315W2 the system automatically provides for the correction of its compounds.

In this respect the conductivity-meter CD315 provides for direct integrations of caustic soda and, proportionally to that, of castor oil as well.

The caustic soda storage tank TK390, equipped with analog level control LVA390 and mechanical overflow alarm LVM390, is fed by the relevant bulk tank via pneumatic ball valve PVC390.

The corresponding piston metering pump PD315S doses the caustic soda solution into the mixing tank TK315 via counter pressure valve VC315S; the flow rate of caustic soda is read by the flow meter FM315S.

The safety valve 735S intervenes activating a by-pass in case of overpressure in the feeding pipe and an alarm is activated by the mentioned flow meter.

The castor oil storage tank TK380, equipped with analog level control LVA380 and mechanical overflow alarm LVM380, is fed by the relevant bulk tank via pneumatic ball valve PVC380.

The corresponding piston metering pump PD315O doses the castor oil into the mixing tank TK315 via counter pressure valve VC315O; the flow rate of castor oil is read by the flow meter FM315O.

The safety valve 735O intervenes activating a by-pass in case of overpressure in the feeding pipe and an alarm is activated by the mentioned flow meter.

Tap water feeds the softening unit, consisting of two water softeners WS302A and WS302B, operated by turn in order to automatically switch to regeneration mode without affecting the soft water supply (dedicated documentation is provided concerning the control valve and the regeneration programmer); a water pressure gauge 341 and a series of interception valves 340 are also provided.

Soft water reaches then the polyethylene storage tank TK601, equipped with analog and mechanical level controls LVA601 and LVM601, via pneumatic ball valve PVC642, to be pumped to the mixing tank by centrifugal pump PMC601.

The relevant flow rate, read by the flow meter FM601, can be adjusted by means of the manual regulation valve VL601.

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The wiping solution in the tank TK315 is kept stirred by mixer ST315 and heated at the requested temperature, checked by the thermocouple TC315, by means of the stainless steel heating coil SER315, which is fed by the centralised hot water group via 3-way proportional valve PV316.

The wiping solution is then pumped to the printing presses by the following centrifugal pumps, all of them activated by the analog level control LVA315L in the mixing tank:

-PMC315A which feeds 6 printing presses via the corresponding wiping solution auxiliary tanks -PMC315B and PMC315C, which feed the remaining printing presses directly.

On the other hand, the concentrate in the storage tank TK401, kept stirred by mixer ST401 controlled by analog level LVA401L, is pumped to the treatment section (tank TK403) by means of screw pump PMV401, activated by level control LVA401W1 and stopped by LVA401W2, via pneumatic ball valve PVC401; the relevant flow rate is read by the flow meter FM401.

PROCESS OPERATION: The Contractor shall operate the system with prudent engineering and operating practices. Operating the system includes, but is not limited to, the following tasks:

(1) The Contractor shall take readings every two (2) hours of the pumps data, flows, tank levels, data set points and operating conditions from the computer, and other set points throughout the system. It should be noted that in the future this may be at least partially performed by SCADA software.

(2) The Contractor shall perform an inspection of the WSWPP every two (2) hours minimally or more often as needed for proper operation.

(3) The Contractor shall start, stop, empty filter presses, prepare the pallets, boxes, liners, fill each box to between >2,300 pounds and ≤ 2,400 pounds, band, properly label, and enter the data into the computer logging system which is furnished by the BEP, for the performance of this contract.

(4) The Contractor shall change/clean filter press filter cloths as needed when they become blinded or physically damaged.

(5) The Contractor shall mix the system materials as needed for the optimal operation of the system.

(6) The Contractor shall check pH set points, loop set points, and local set points; and calibrate pH meters weekly at a minimum or more often, as needed.

(7) The Contractor shall respond to all alarms, correcting the conditions to assure proper operation of the system.

(8) The Contractor shall clean and inspect the tanks at least annually as well as clean the tanks and affected equipment if there is a blockage (build-up)

Attachment 5 Page 5 of 5 Pages of sludge in any tank as necessary during the operation of the system.