Need for New Method of Liquid-Solid Separations
for Small Batch Operations

In the pharmaceutical, fine chemical, hazardous materials, juice, beverage, beer, and wine industries, most of the production processes are batch in nature. This batch nature is due to the limited volume of the material to be processed, the need for traceable "lots" of material, and/or the high intrinsic value of the product. Processes in these industries frequently require equipment that performs efficient, clean, and reliable solid-liquid separations. Applications in these industries could range from:

Currently these batch Liquid-Solids Separations are carried out using centrifuges and/or batch filtration equipment like plate and frame or leaf filters. Although these types of traditional equipment have been used for years, they have some inherent disadvantages, especially when applied to laboratory, pilot plant, or other small capacity production applications. This traditional equipment also has disadvantages where time and resources are limited and it is critical that the materials be isolated from the outside environment.

Centrifuges can be expensive to purchase, involve high maintenance and a great deal of personnel involvement to operate under aseptic or "clean" conditions. Batch filtration equipment can also be expensive and involves a high degree of operator attendance. Both types of units used in the small production environment may be so radically different than that available for commercial production, that scaleup is costly. In addition, centrifugation and batch filtration present costly manual cleaning operations that require the unit to be opened to the environment. This, in turn, leads to chances of exposure of the material being processed to the outside "uncontrolled" environment, increasing the risks to the final product as well as to operations personnel. Because of this, there is a need for another type of equipment to conduct these solid-liquid separations that addresses some of the short-comings mentioned above.

The solution to this problem lies in adapting the primary solid-liquid separation device used in the Chemical Process Industries (CPI) to pharmaceutical, fine chemical, food, beverage, and other low to medium volume applications. This device is the Disposable Rotary Drum Filter. The key importance of this device is that it can be run semi-continuously. Thus a batch of product is run though it for a period of time in a steady state fashion. This semi-continuous operation allows the equipment to be very small as compared to batch equipment that would handle the same amount of material. This reduction in size has some distinct advantages, namely that the device is easily enclosed, enhancing its ability to resist potential contamination of the product or personnel. Also, because of its size the unit can be made of plastic and disposable.