Patent RU-2674610-C1 (RU)
Title: Method for drying high-moisture disperse materials and device for its implementation
Inventor: DRANNIKOV ALEKSEJ VIKTOROVICH
IPC: A23L3/40
Filed: 2017-11-21
Granted: 2018-12-11
Abstract: FIELD: technological processes; food industry.SUBSTANCE: invention relates to the food and feed industry and can be used for drying, for example, materials such as beet pulp, apple and grape pomaces, etc. Method involves a 2-stage drying. At the first stage, the initial material is pre-dried with superheated steam of the atmospheric pressure of the material in a pulsed vibrating layer at a temperature of 130...140 °C, and on the second stage – drying in a fluidized bed with superheated steam of reduced pressure at a pressure of 20...30 kPa and a temperature of 90...100 °C. Exhaust superheated steam of atmospheric pressure with a temperature of 110...115 °C is divided into two streams. One steam stream is sent to overheat to a temperature of 130...140 °C with heating steam with a temperature of 160...170 °C, then return to the first stage. Second steam stream in an amount equal to the amount of moisture evaporated at the first stage from the material, is supplied to superheat the reduced pressure to a temperature of 90...100 °C. Exhaust superheated steam of reduced pressure with a temperature of 70...75 °C is also divided into two streams. One steam stream is sent to overheat to a temperature of 90...100 °C with exhaust superheated steam at atmospheric pressure, then return to the second stage. Second steam stream in an amount equal to the amount of moisture evaporated from the material in the second stage is used to create a reduced pressure of 20...30 kPa during condensation in countercurrent steam flow with cold water having a temperature of 10...15 °C. Device consists of chamber for drying with superheated steam of atmospheric pressure (1) and chamber for drying with superheated steam of reduced pressure (2), which are hermetic, connected in series with sluice gates (3, 4 and 5) and arranged in a vertical plane. Each drying chamber contains inside sloping perforated grid (6 and 8) and is equipped with inlet pipes (9 and 11) and outlet (10 and 12) of superheated steam. Camera (1) additionally includes vibration drive (7) of grid (6) located on the outside of chamber (1). Device includes initial material preheater (15), steam generator (19), pumps (18, 23), condenser (24) with barometric tube (28) and condensate collector (29), fans (17 and 22) and steam superheaters for superheated steam of atmospheric pressure (16) and reduced pressure (21), flow dividers of exhaust superheated steam of atmospheric pressure (13) and reduced pressure (14). Each of the flow dividers contains two outlet pipes, one of which is connected to the inlet pipes of chambers (1) and (2) with the formation of two recirculation circuits. Second pipe (10) is included in the circuit containing successively installed steam superheater (21), pump (23) and preheater of initial material (15). Second pipe (25) is connected to condenser (24) equipped with pipes for discharging non-condensed gases (27), cold water inlet (25) and barometric pipe (28) with condensate collector (29). Device contains a recirculation circuit that includes steam generator (19) with safety valve (20), steam superheater of atmospheric pressure (16) and pump for heating steam condensate (18).EFFECT: reduction of the metal consumption of the device, an increase in the intensity of drying, a reduction in the consumption of heat directly for drying the material and a decrease in the consumption of cold water in the condenser are provided.2 cl, 1 dwg