Recirculating Vessel Samplers
Our recirculating sampling systems utilise a pneumatically operated pump to first create suction to draw the sample which could be highly corrosive liquor up a dip tube mounted on a the vessel lid into the system then to pump it around the system before discharging back into the vessel, the sampler can be run for several seconds beforehand to ensure that there is a representative sample passing through the system before a sample is taken.
After a sample has been obtained the inlet isolation valve is closed and gas such as nitrogen introduced into the system to purge the system clear ready for the next use, a wash liquor can also be used and pumped around the system and discharged into the vessel if required.
The discharge from the pump back into the vessel can be to a separate nozzle or more usually to the same nozzle and is connected via an instrument tee that sits underneath the dip pipe allowing the return liquor to fall back into the vessel around the outside of the dip pipe whilst fresh sample liquor is drawn up the bore of the dip pipe from the submerged end. The discharge to the vessel can be through a PTFE hose assembly or hard piped using our HiPerFlon lined piping.
There is a wide choice up pumps available and we typically try to follow the customers site standard. Double diaphragm pumps machined from solid PTFE blocks are suitable for use up to 100° C, beyond that we supply our sampling systems with a tubular diaphragm pump which can be used in processes up to 180°C.
Materials of construction are usually PFA / PTFE lined with borosilicate glass viewing windows and PTFE seals, these are chosen to allow the samplers to be used to sample highly corrosive processes containing HCL, Sulphuric acid etc. Our customers specify recirculating sampling systems where they require in process sampling of batches of product as they are mixed in reactor vessels to ensure the correct parameters are achieved, allowing them to adjust the chemistry as required whilst producing the batch of product.
The sample is dispensed from the system as the pump drives the sample of the vessels contents through the system, we use a SD-IL-400 inline sampler with lockable spring return handle as this provides simple operation and robust construction. We include a sight glass which could be a tubular or bulls eye type for visual indication of flow around the system.
There are many additional features and functions that can be integrated into our recirculating sampling systems, for example, pH probe mounts, powder seeding option, turbidity sensors, temperature sensors etc. Other additional features such as double isolating actuated valves can be included, we are here to discuss the requirements with our customers and arrive at the best solution.
We have applied our years of experience in vessel contents sampling and have created our Compact Recirculating Sampling System which incorporates all the best features in a small spaced envelope.
We would normally use Atomac ball valves in our design, knowing that they offer excellent sealing performance and have provided decades of service to our customers. The PFA lined valves are perfect to control the flows through our sampling systems and so are our first choice.
As with all our samplers and sampling systems we would recommend that the sample bottle is contained within safety cabinet, this protects the bottle, operator and environment. Our standard cabinet is stainless steel with a laminated glass door.
To help specify a sampling system we have a questionnaire which you can download.