NEWSLETTER
ISSUE
Issue Jan to Mar, 2024 Volume 22
BRAIN WAVE
BRAIN WAVE - VAPOSTIL™ for WFI generation
In recent times, the accelerated growth of the pharmaceutical industry has caused demand for larger-volume production especially in the sterile manufacturing facilities. Water for Injection (WFI) is an essential requirement in these facilities, leading to the need of high-volume production of WFI.
WFI is also widely employed for manufacturing biologics and medical devices. It finds application as a solvent in the preparation of injectable drugs – including antibiotics, vaccines, and other medications administered through intravenous, intramuscular, or subcutaneous routes. WFI is utilized in the formulation of sterile products, such as eye drops and inhalation solutions.
The United States Pharmacopeia (USP) has specified guidelines with defined references for the microbial, endotoxin, TOC and other substances that determine the quality of WFI.
As WFI comes into direct contact with the human body through injections, infusions, or inhalation, it must be free from impurities and contaminants to prevent any adverse effects on patients.
The stringent purity requirements demand specialized equipment and tailored processes for large volume production.
Two key proven processes for production of WFI are – distillation and filtration. The distillation process purifies water by the change in phase and entrainment separation. There are several methods employed for production of WFI by distillation, such as single-effect distillation, multiple-effect distillation, and vapour-compression distillation.
The Vapour Compression Technology has important advantages :
- High thermodynamic efficiency
- Less stringent feedwater requirement
- Simpler pretreatment systems
- Reduced footprint
- Reduced risk of cross-contamination
The underlining point of difference in this technology is the usage of mechanical compressor for distillation. Usage of compressor draws concern regarding its maintenance and reliability. However, these challenges are negligible compared to the advantages for large volume production that support use of the vapour compression technology. Periodic maintenance of compressor provides quick health check and helps avoid downtime. The new age compressors have shown positive results for reliability, eased maintenance, consume less energy, generate less noise, lessened the installation costs and simplified the operation.
In a typical unit employed for pharmaceutical distillation, softened, and dechlorinated water is boiled inside the tubes (in the evaporator). A mist separator removes the entrainments from the vapour. This purifies the vapour which enters the compressor at a controlled saturated pressure.
In the compressor the vapour is compressed causing generation of saturated steam. Discharge of this high-pressure, high temperature steam occurs in the shell side. It then transfers its heat to the boiling water in the tube causing condensation and release of latent heat, thereby producing WFI.
The Pharmalab VAPOSTIL™, is our technology from the future that utilizes the vapour compression system for producing WFI.
The VAPOSTIL™ consists of:
- Compressor and its Drive Motor
- Evaporator
- NCGR system
Compressor and its Drive Motor
It compresses the vapour generated in the evaporator. This increases its pressure (and temperature), which creates the temperature gradient necessary for the heat-transfer process and allows for the recovery of latent heat.
The VAPOSTIL™ compressor consists of a highly efficient centrifugal closed-type single stage impeller blower and VFD controlled permanenet magnet synchronous motor (PMSM). The PMSM offers the optimum speed and is assembled in a closed cabinet. The specialized arrangement of the direct driven motor facilitates delivery of higher torque with smaller frame size and no rotor current. The automatic closed bearing lubrication system guarantees seamless operation. WFI demand can be regulated by controlling the compressor speed. The direct-driven motor of the compressor eliminates the usage of intermediate couplings.
Evaporator
The evaporator consists of a bottom head, a calandria and a dome. The bottom head is provided with a heating coil for initial heating of infeed water. The calandria is composed of a shell and bank of tubes for the exchange of heat from the compressed vapour to the infeed water. The dome consists of an arrangement for the removal of entrainment and the collection of vapour for compression.
The VAPOSTIL™ guarantees efficiency while providing reliability and performance at minimum costs. Higher capacities demand can be met to cater to the large volume production needs.
