Упражнения

1. Ответьте на вопросы:

1. What does freeze-drying involve?

2. Where does the sublimation take place?

3. What accelerates sublimation?

4. What is IQF?

5. Did IQF make a good influence on frozen food?

6. What is the final operation in many manufacturing processes?

7. In many cases the nature of the controlling factor, isn't it?

8. What is the deciding factor in drying food products?

9. Does each group of materials have its own class of driers?

10. What types of driers do you know?

2. Дополните предложения словами и сочетаниями из текста.

1. Freeze-drying involves...

2. Product is first frozen at... temperature.

3. The ice crystal pass into the... phase.

4. Before the advent of IQF, frozen fruit and vegetables came frozen in...

5. The process of IQF arrested the ... process.

6. The process of IQF makes the ... superior to fresh.

7. Drying is not only a matter of removing...

8. Liquids containing dissolved solids are handled in ... driers.

9. Wet solids are dried in ... driers.

10. ... are closets in which the material is spread on trays.

Indirect Rotary Driers

It consists of rotating cylinder inclined to the horizontal, with material fed to one end and removed from the opposite end. Drying is accomplished indirectly, heat is being conducted to the material through the metal shell or tubes, or through cylinders placed in the rotating shell. The simplest type of this dryer consists of a rotating cylinder encased in a brick or steel housing that is also the combustion chamber. Flights are used on the main drying cylinder and on the outside of the inner hot-air duct. Moisture vapor usually leaves at the feed end of the drier through a stack or an exhauster.

In another type, hot gases pass through an inner concentric fluted cylinder and then back through hollow flights attached to the outer cylinder.

The most common type of indirect rotary dryer is the steam-tube dryer. Steam-heated tubes are fastened symmetrically in one, two or three concentric circles to the inside of the cylinder and rotate with it. When the materials are sticky, only one row of tubes is used. Flights are sometimes used to promote agitation of the material. Wet material may enter the dryer through a screw conveyor or gravity chute. The product discharges from the dryer through peripheral openings in the shell.

Пояснения к тексту

drier – сушильный прибор

rotary –вращательный, ротационный

vapor – пар

stack – (дымовая) труба

steam – пар, паровой

tube – труба

sticky – липкий, клейкий

wet – сырой, мокрый

1. Перепишите следующие предложения. Подчеркните в них сказуемые. Определите их временную форму и залог. Переведите предложения на русский язык.

1. Heat is being conducted to the material through the metal shell or tubes.

2. The product discharges from the dryer through peripheral openings in the shell.

2. Найдите в тексте предложение с модальным глаголом. Выпишите и переведите его. Подчеркните сказуемое.

3. Выпишите из текста предложения с Participle IІ. Подчеркните Participle II и определите его функцию (определение, обстоятельство). Переведите причастия на русский язык.

4. Поставьте вопросы (четыре) к тексту: общий, специальный, альтернативный, разделительный.

5. Ответьте письменно на вопросы:

   1. What does an indirect rotary drier consist of?

   2. What is the common type of an indirect rotary drier?