LEAD DIVISION
nanofiltration skid FOR LEAD BATTERY RECYCLING
The nano-filtration system makes part of the crystallization process of decahydrated sodium sulphate (Glauber’s Salt) operating in the desulphurization unit of lead battery recycling plants.
lead.stcitaly.com
NANOFILTRATION SKID
OPERATING PRINCIPLE
The nano-filtration system treats the mother liquors coming from the crystallization of the dechydrated salt (feeding liquid), which contain still 5% of sodium sulphate in solution, and re-inserts them in the crystallization process with a concentration higher than 15% (concentrated liquid). The permeate (diluted liquid), instead, is sent to the process water collecting tank of the lead battery recycling plant. The incoming solution is filtered in a mechanical cartridge filter in order to eliminate solid particles that would block the osmosis membranes in shorter times respect to regular period. Afterwards the solution enters in the multistage centrifugal pump for pressurization. The pressurization is necessary because the membranes of the nano-filtration need high pressure to be able to have permeate flows corresponding to project specification. The solution enters first in two parallel membranes and then in two vessels located in series. Each of the four vessels produces a permeate current which is collected in a single basin. The connections for the concentrate and the permeate are located in front of the skid. Each vessels has three membrane modules of nano-filtration 8040 (8 inches diameter rated for 40 inches length) connected in series. The plant is equipped with analog and digital instrumentation for its operation. The switchboard is installed on the front side and controls the electric feeding as well as the commands throughout PLC. The nano-filtration plant of the lead battery recycling process operates at a pressure of maximum 50 bar: the pressure equipments have inferior characteristics respect to the limits fixed by the PED (Pressure Equipment Directive) and therefore make part of the exemptions of art. 3 comma 3 of the same directive. NANOFILTRATION Maximal amount of space Width
4700 mm
Height
2300 mm
Depth
1351 mm
Weight
1400 kg
Replenishment volume
700 l
Osmosis modules
12 modules 8040
Installed power
24 kW
Maximum pressure
48 bar
Materials Frame
Fe430B
High pressure tubes
AISI 304
Low pressure tubes
PVC
Tanks
PE
Electric feeding
400 Volt 3Ph 50Hz
Max electric power
64 Ampére
Protection grade IP
IP55
Noise
70dB(A) at 1 m distance
MULTISTAGE CENTRIFUGAL PUMP FOR PRESSURIZATION Brand/Model
Lowara Z612 47D-L6W
Weight
200 kg
Material
AISI304
Power
22 kW
Maximum pressure
55 bar
Medium capacity
5 m3/h
Electric feeding
400 Volt 3Ph 50 Hz
Rotation per minute
2835 rpm
STC srl LEAD DIVISION
Via A. Murri, 22 (Z.I.) • 72023 Mesagne (BR) • Italy Tel/Fax: (+39) 0831 738018 • www.stcitaly.com • info@stcitaly.com
lead.stcitaly.com