Plate Evaporators

Instead of tube and shell heat exchangers, framed plates can be used as an heating surface. These plate assemblies are similar to plate heat exchangers, but are equipped with large passages for the vapor flow. In these units a product plate and a steam plate are connected alternately. The product passage is designed for even distribution of liquid on the plate surfaces and low pressure drop in the vapor phase.

Figure 1: Plate Evaporator

A) Product B) Vapor C) Concentrate D) Steam E) Condensate F) Excess Vapor 1) Plate Evaporator 2) Separator

Plate evaporators are of compact design. Separators are flanged directly to the plate packages with short interconnecting pipe-work. Thus, space requirements are low and the building height normally does not exceed 10-13 ft (3-4m). This means that plate evaporators can be installed in most buildings. Very often GEA Niro Inc. delivers these units preassembled as skid-mounted systems, further simplifying installation.

5-effect plate evaporator, directly heated, with plate condenser, aroma recovery and concentrate cooling system. Product: apple juice at 11% TS. concentrated to 72% TS. Evaporation rate: 25,000 lbs/hr (~11,340kg/h).

The steam and product plates are separated by gaskets. In GEA Niro Inc. plate evaporators the gaskets are held in specially designed slots without adhesives and stay in place, even when the plate pack is opened.

They are designed for single pass rising film operation. This results in even and gentle evaporation of the product. Depending on the duty, the evaporator can be operated with product circulation as well.

Since the plate package can be opened easily, surfaces can be inspected, individual plates changed if necessary, and the evaporation rate can be altered by adding or removing individual plates. The units can be designed to meet USDA Dairy sanitary requirements.