Text № 9. Pump Motors

Pumping is one of the major duties performed by powerhouse auxiliary equipment, and usually the largest motors in the station are those that drive the boiler-feed-pumps. In a typical station the total horsepower rating of the boiler-feed-pump motors is between five and six percent of the kilowatt rating of the associates turbine. At least two and usually three boiler-feed pumps of equal rating are used. These pumps operate against a very high head of water and require 3,600-rpm driving motors.

The output of the boiler-feed pumps is controlled by throttling or by varying the speed of the pump. The latter method is attractive because of reduced operating cost. Variable-speed control, when used, is achieved with a variable-speed coupling or by using a wound-rotor motor and a liquid rheostat.

The torque requirements of boiler-feed pumps and most of other pumps are satisfied by motors with low starting current and normal starting torque. Most boiler-feed pump motors are rated for a temperature rise of 40 degrees C above ambient and have class A insulation. Where the ambient temperature is above 40 degrees, class B insulation is used.

Although drip-proof construction is usual, special enclosures are sometimes use to reduce the noise level of the motor or to protect the motor from flyash and other unfavorable atmospheric conditions. Noise can be reduces by using pipe-or base-ventilated motors in which the inlet and exhaust for cooled by air-to-air at a remote location. In particularly dirty locations enclosed motors are used. Air for such motors is cooled by either an air-to-air or an air-to-water heat exchanger. Since outside air is never drawn into the motor, the windings are protected from contamination.

In addition to boiler-feed pump, numerous other pumps are associated directly with the water cycle of the plant or perform auxiliary functions. These include pumps for handling circulating water, condensate, drain water, raw water, water-purification chemicals, ash, flood water, water for fire protection, sump water, lubricating oil, and station water supply. Usually the largest of these are the circulating water pumps. In a typical station, there are two circulating water pumps per turbine with the total horsepower for slightly less than one percent of the turbine rating. The size od driving motor in a particular application is determined by the head and capacity requirements, which are influenced by the nature of the water source.

Text 10. Why is a Business Plan important?

The success of your business depends largely upon the decisions you make. A business plan distributes resources and measures the results of your actions, helping you set realistic goals and make decisions.

Lack of planning doesn’t allow making future decisions and actions you must take to run your business successfully. On the other hand, a sound plan can act as:

· A reality check. The process of putting together a business plan forces you to take an objective, critical, unemotional look at your business project in its entirety.

· An operating tool. Your written business plan is an operating tool which, when properly used, will help you manage your business and work effectively towards its success. Your business plan will allow you to set realistic goals and objectives for your company’s performance, and will also provide a basis for evaluating and controlling the company’s performance in the future.

· A message sender. The completed business plan communicates your company’s ideas to employees, outside directors, lenders, and potential investors. A business plan helps you do that in an organized manner. Also, the process of planning helps you determine if your vision is realistic, and tells you what you need to do in order to achieve it.

· A motivation tool. The development of your business plan is one of the best ways for you to communicate how well you understand your business and describe your vision of your business. Without proper planning, it becomes impossible for you to get all of your employees to understand the goals and objectives of business. It is impossible to motivate people when they do not know where they are going or what they are trying to achieve.

· A management development tool. Putting together your business plan will help you develop as a manager because it can give you practice in thinking and understand the problems about competitive conditions and situations that are or may be beneficial or harmful to your business.