Simdean Group have successfully designed, manufactured, installed and commissioned a new carbon adsorption system at a large pharmaceutical research and production facility situated in Limerick, Ireland.
A by-product of the production process is liquid waste which is classed as contaminated and emits odorous vapours. The liquid waste water is stored in large glass lined tanks where it is treated and purified by various chemical processes before being discharged safely.
The pharmaceutical company contacted Simdean who were very happy to discuss the issues, survey the site, and design an appropriate system in order to contain and eliminate the odour problem.
In this particular case the best solution was to use an annular bed carbon adsorber, powered by a fan unit via a fresh air mixing damper and system of ductwork.
It was estimated that the activated carbon required would be capable of adsorbing approximately 20% of its own weight and the total weight of carbon within the Adsorber would be approximately 3.1 tonnes. This meant that a total of 0.6 tonnes of “contaminants” could be adsorbed within the carbon which would give an estimated effective carbon life of at least 12 months.
The Carbon Adsorber was housed in a GRP clad Polypropylene constructed housing.
The adsorber was internally split between general purpose activated carbon and used to remove in general basic and neutral odorous components in the gas stream and impregnated activated carbon used to remove in general acidic odorous components and act as a polishing bed. The total flowrate through the adsorber is 5,200 m3/h and the total retention time within the Adsorber is approximately 2 secs.
The basket for the retention of the annular carbon bed was constructed from type 304 stainless steel of fully welded construction with access panels for ease of removal of the carbon during changeout procedures. Mechanically the basket was designed to contain the weight of carbon as a self-supporting unit.
The bulk of the system and carbon adsorber was installed onto a purpose designed steel platform which provided access via a ladder up to the plant to enable ease of maintenance. The system was designed to be capable of handling 5,200 m3/h of contaminated air and was powered via a polypropylene centrifugal fan unit. A range of polypropylene field ductwork and dampers was installed to connect the five effluent tanks and provide efficient containment.
The control panel consists of a coated sheet steel, wall mounted enclosure protected to IP55 containing an Allen Bradley programmable controller complete with HMI touch screen for incorporation into a SCADA system for overall control of the system. The control panel is capable of providing the SCADA monitoring and datalogging of a number of critical parameters.
The system was controlled via various pressure and temperature sensors located within the installation and feeding all information into the PLC. The airflow would be automatically controlled via auto-dampers to regulate temperature and humidity and energy use would be minimised by the use of inverter control on the prime mover in this case a centrifugal fan unit.
The entire system was commissioned within 2 days and after trials and a running in period the customer was extremely pleased with the result. All odours from the process have been effectively contained and are treated efficiently by the system.
The inlet and outlet ductwork connecting the adsorber were provided with sample ports to allow for measurement of odour concentrations thereby allowing operators to determine the most cost-effective time to replace the activated carbon.