Overview of Process Optimization and Scale-up Services
It is quite often the case that companies are interested in the benefits that ultrasound provides, but do not have the technical experience and/or equipment to test the efficacy of ultrasound on a unique process or substrate. ISM is capable of providing testing, measuring, and results dissemination services, in addition to advising its clients on the process improvement.
After the initial feasibility assessment is done, many clients ask us to optimize their ultrasonic process and estimate the potential commercial-scale production rate. This is commonly a two or three-step procedure:
Step 1. Laboratory-scale studies aimed at optimizing basic process parameters, such as components ratios, ultrasonic amplitude, specific reactor residence time, static pressure, temperature, etc. This step is normally done in a batch or small-volume flow-through mode, utilizing a conventional ultrasonic horn (CH) with and output tip diameter of 13 -15 mm. Electric power consumption during this step is commonly 100 - 150 W.
Step 2. Pilot semi-industrial scale study during which all optimized parameters are retained, while the size of the ultrasonic horn and reactor chamber is increased, thereby increasing the flow-through rate. Since the scale-up is accomplished without changing any of the parameters optimized in step 1, the product quality is expected to remain unchanged. This step is normally done in a flow-through mode, utilizing a Half-Wave or Full-Wave Barbell Horn (HBH or FBH) with an output tip diameter of 30 - 35 mm. The goal of this step is to determine the exact scale-up factor between the lab and the pilot setting and to ensure that the quality of the product is unchanged. For most processes the scale-up factor turns out to be between 8 and 12 which means that approximately 8 to 12 times more product is produced per unit of time. Electric power consumption commonly also goes up by a similar factor and reaches approximately 900 - 1200 W.
Step 3. The results obtained during Step 2 can normally be used to predict the scale-up factor that will be achieved when the process is transferred to the plant floor. However, it is sometimes necessary to run a full-scale study to ensure that this prediction is in fact accurate. This verification is done by further increasing the horn (HBH or FBH) and the reactor chamber sizes, commonly resulting in a productivity rate (and electrical power consumption) increase by an additional factor of about 3 - 4.
Based on the above, for an average process an overall per-processor production rate scale-up factor of 25 – 50 can be expected when transferring the process from lab to industrial scale. An example of process optimization and commercial-scale production rate estimation study is given in a separate document.