+ The Spent sample from the analyzer and sample conditioning systems (drains) will be collected into a skid mounted Sample Recovery System consisting of a collecting vessel, with level indicators and level switches and with a properly sized pump to return the sample to process.
+ The complete unit, together with all electrical equipments (power distribution, Pump start stop panel and pump logic), will be mounted on a free-standing metal framework to be located near-by the Analyzer House or Cabinet.
+ Sample drains from the analyzers will be connected to the top of the vessel.
+ The vessel will be fitted with four level switches (High; HH and Low; LL), for pump on/off operation: one for low level alarm (LL Alarm) and one for high level alarm(HH).
+ The pumps(1 or 2) discharge will be connected to a pre-selected point in the process.
+ When the level in the vessel reaches a predetermined high Position (High Level), the pump is started to return sample to the process. When the level reaches a predetermined low position (L level), the pump is stopped. The level switches (HH) and (LL) are for alarm at high and low level respectively and for vessel and pump protection.
+ Normally the vessel will be sized to provide at least 30 min hold-up between the level switches operating the pump. The pump will have a minimum design capacity of 200% of total sample in-flow rate.
+ The Vessel capacity depends on the number of analyzers and sample worked.
+ The control unit (PLC) shall be installed in to Eex-d box.