Poultry rearing

Power is used in the poultry industry to drive fans for incubation, ventilation, the feeding system, egg collection and grading. In the main, single power units are small and installations often use several fractional horse power motors.

Incubators. In all but the smallest incubators, fans or air circulators of paddle type are used to move air gently round the eggs. The fans are slow-speed units and paddles, when used, are driven through belt or chain drive or geared motors.

Ventilation. By using ventilating fans temperature and humidity can be kept within generally acceptable limits. There are many different types of ventilation systems.

Very broadly, the systems fall within two groups, one using small multi-fan units and the other, large single fans with a distribution duct system. Both groups can extract air from the house, or the house can be «pressurized», i.e. fan (fans) blows air into the house and the stale air is ex­hausted from separate outlets. Whatever the system, a good even distribution of air going into the house is essential. Ventilation rates are calculated according to the number and type of birds being housed with control by temperature. Speed of fans can be controlled by thermostat, with some fans in a multi-fan installation being stopped by a further thermo­stat if a very low ventilation rate is required, but care must be taken that air distribution is not upset.

Feeding and Egg Collection. Feeding systems consist usually of conveyors which carry the food from a bulk supply point into the house. The conveyors may be augers, chain-and-f light types or pneumatic pipe systems. Small motors from fractional horse power to 3 hp are necessary. Control is usually by a time switch.

Mechanical collection of eggs, by an endless belt fromthe point of lay to a central position, is sometimes employed as well as mechanical grading. Small motors, up to 1 or 2 hp, are usually sufficient.

ВАРИАНТ 4.

I. Перепишите следующие предложения; подчеркните в каждом из них глагол-сказуемое и определите его видовременную форму и залог. Переведите предложения на русский язык. В разделе (б) обратите внимание на перевод пассивных конструкций.

а) 1. He has forgotten his English since he graduated the Academy.

2. The problem of the structure of matter is constantly occu­pying the minds of many scientists.

б) 1. Fifty students were admitted to the faculty last August.

2. Many compounds can be decomposed when they are acted upon by different forms of energy.

II. Перепишите следующие предложения; подчеркните Participle I и Participle II и установите функции каждого из них, т.е. укажите, является ли оно определением, обстоя­тельством или частью глагола-сказуемого. Переведите пре­дложения на русский язык.

1. They reminded at home refusing to go anywhere that day.

2. Matter composed of any chemical combination of elements is called a compound.

3. The smallest particle having all the characteristics of an el­ement is called an atom.

4. When started and completed its construction became the best.

III. Перепишите следующие предложения; подчеркни­те в каждом из них модальный глагол или его эквивалент. Переведите предложения на русский язык.

1. Heat can be divided into three different types.

2. He was to stay at the office until the report was ready.

3. Chemical means had to be used for the separation of com­pounds into their elements.

4. The existence of this theory laser in the future may be possi­ble.

IV. Перепишите и письменно переведите текст.

Дата добавления: 2015-06-28