Máy sấy phun cùng chiều

2 dạng hệ thống sấy phun mở

Hệ thống sấy phun cùng chiều mở1. drying air Không khí khô2. feedstock Nguyên liệu3. dried product Sản phẩm sau sấy4. drying chamber Buồng sấy5. cyclone Cyclon6. wet scrubber Buồng lọc ướt

7. bag filter Túi lọc8. electrostatic precipitator Buồng lắng tĩnh điện

1. drying air Không khí khô2. feedstock Nguyên liệu3. dried product Sản phẩm sau sấy4. drying chamber Buồng sấy5. cyclone Cyclon6. Alt. A: wet scrubber Buồng lọc ướt7. Alt. B: bag filter Túi lọc8. Alt. C: electrostatic precipitator Buồng lắng tĩnh điện

Máy sấy phun ngược chiều Counter-current flow dryer

In this dryer design (Fig. 2.2.1), the spray and the airare introduced at opposite ends of the dryer, with theatomizer positioned at the top and the air entering atthe bottom. A counter-current dryer offers more rapidevaporation and higher energy efficiency than a cocurrentdesign. Because the driest particles are incontact with hottest air, this design is not suitable forheat-sensitive products. Counter-current dryersnormally use nozzles for atomization because theenergy of the spray can be directed against the airmovement. Soaps and detergents are commonlydried in counter-current dryers.

2.3 Mixed flow dryerDryers of this type (Fig. 2.3.1) combine both cocurrentand counter current flow. In a mixed flowdryer, the air enters at the top and the atomizer islocated at the bottom. Like the counter-currentdesign, a mixed flow dryer exposes the driestparticles to the hottest air, so this design is not usedwith heat-sensitive products..

Semi-closed Cycle Layout Hệ thống sấy bán khép kín (đóng)(Self-inertizing)Fig. 2.6.21. combustion air Khí đốt2. coolant Chất tải lạnh3. feedstock Nguyên liệu4. heater fuel Nhiên liệu đốt5. condensed water discharge Tháo nước ngưng6. dried product Sản phẩm sau sấy7. drying chamber Buồng sấy8. cyclone Cyclon9. direct heater (gas) Buồng cấp nhiệt trực tiếp10. heat exchanger Buồng trao đổi nhiệt11. scrubber/condenser Buồng lọc cặn12. air bleed to atmosphere Thóat khí ra ngoài

2.7 Single stage dryerIn a single stage dryer, the moisture is reduced tothe target (typically 2% - 5% by weight) in one passthrough the dryer. The single stage dryer is used inthe majority of designs.2.8 Two stage dryerIn a two stage dryer, the moisture content of productleaving the chamber is higher (typically 5% - 10%)than for the final product. After leaving the chamber,the moisture content is further reduced during asecond stage. Second stage drying may be done ina fluidized bed dryer (Fig. 2.8.1) or a vibrating beddryer (Fig. 2.8.2). Two stage dryers allow the use oflower temperatures in the dryer, making the design agood choice for products that are particularly heatsensitive.

Two Stage Dryer with Fluid Bed DryerFig. 2.8.11. air không khí2. feedstock nguyên liệu3. dried product sản phẩm sau sấy4. drying chamber buồng sấy5. cyclone cyclon6. stationary fluid bed buồng ổn định dòng sản phẩm7. fluid bed cyclone cyclon tầng sôi8. transport cyclone

Two Stage Dryer with Vibrating Bed Dryer1. air2. feedstock3. dried product4. drying chamber5. cyclone6. vibrating fluid bed7. fluid bed cyclone8. transport cyclone

9.13 Milk ProductsBy volume of product dried, the dairy industry is byfar the largest user of spray dryers for foodprocessing. Skim milk, whole milk and fat-enrichedmilk are the most important milk products that arespray dried. Other dried milk products include

casein, caseinate, whey, sweet whey, acid whey,deminerialized whey, whey protein, infant formula,coffee whitener, cheese, ice cream mix, butter milk,butter, flavored milks and cream.Milk is always concentrated in falling-filmevaporators to a solids content of 45%-55% beforespray drying because the cost of removing water inan evaporator is about 1/10 the cost of removing it ina spray dryer.Both rotary atomizers and pressure nozzles havebeen used to atomize milk products in the past, butin recent years, rotary atomizers have been replacedalmost entirely by nozzles.Whey is a by-product of cheese making, but it is acommercial product in its own right. Whey is used insoups, cake mixes, baby foods and nutritionalsupplements.Spray dried milk products are re-dissolved or drymixed when utilized. Important powdercharacteristics are: flow properties, wettability,sinkability, dispersability and solubility.The general properties of milk powders are: acidity,microbiological properties, state of fat (physical andchemical), organoleptic properties, composition (%fat and % solids, and functional additives.The properties of milk powders that are influenced byprocessing are: free moisture, particle sizedistribution, bulk density, wettability, dispersibility,sinkability, rate of hydration, flow properties, friability,hygroscopicity, caking and shelf life.Milk powder faults influenced by processing are:solubility index, scorched particles, free fat, scum,white flecks and specks.Milk productsBaby foodButter (high fat products)ButtermilkCaseinCaseinatesCheeseCocoa milk with sugarCoffee whitenerFat-filled milkFat-filled wheyHydrolyzed milk productsCreamIce cream mixMalted milkMilk replacerMixed milk productsSkim milkWheyWhey mother liquorWhey permeateWhey proteinWhole milk