Curb presses

Expression. Both sedimentation and filtration are suitable separation techniques when the mixture of liquid and solids is sufficiently mobile to allow pumping, or similar method of motion, of the fluid to a barrier which retains the solid but not the liquid. If such movement is not possible then separation can be accomplished by compressing the mixture under conditions which permit the liquid to escape while retaining the solid between the compressing surfaces. This technique is called expression. Design of expression equipment is varied. Batch systems usually operate by the application of hydraulic pressure in units such as the box press, pot press, curb press and cage press. Continuous expression utilises equipment such as screw presses, roller mills, and belt presses [23]. 

The important elements are a mechanical digester or macerator and a small press. The digester consists of a horizontal barrel fitted with rotating beater arms and operated by a small diesel engine. This breaks up the fruit flesh into a pulp. The oil is extracted from the pulp either in a curb press, in which a heavy metal plate is forced down on to the charge in a perforated or slotted cylindrical container by means of a screw thread turned manually or in a small hand operated hydraulic press. These two devices enable up to 90% of the oil content to be recovered. The nuts are separated manually from the press residue and processed separately. 

Harvey, G. (1994). Transportation Pricing and Travel Behavior. In Curbing Gridlock Peak Period Fees to Relieve Traffic Congestion, Vol. 2. Washington, DC National Academy Press. 

Various types of equipments are available. The principal batch presses are the box, platen, pot, curb, cage [5], and tube press. A filter press with a compression device is widely used in various fields. For continuous operation, the screw press, the roller mills, and the belt press are in common use. In connection with drying operations, the following devices are explained. 

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