1. Chiller - oхладитель

2. Wet bulb temperature

3. Dry-bulb temperature

4. Heat pump – тепловой насос

5. Water loop – водяная петля

6. Cooling mode – режим охлаждения

7. Heating mode – режим нагрева

8. Winterize - подготовить к зимней эксплуатации

9. Boiler – паровой котел

Text №15

Industrial cooling towers

Industrial cooling towers¹ can be used to remove heat from various sources such as machinery or heated process material. The primary use of large, industrial cooling towers is to remove the heat absorbed in the circulating cooling water systems used in power plants², petroleum refineries³,petrochemical plants⁴, natural gas processing plants, food processing plants⁵, semi-conductor plants⁶, and for other industrial facilities⁷ such as in condensers of distillation columns, for cooling liquid in crystallization, etc.^[3] The circulation rate of cooling water in a typical 700 MW coal-fired power plant with a cooling tower amounts to about 71,600 cubic metres an hour (315,000 U.S. gallons per minute)^[4] and the circulating water requires a supply water make-up rate of perhaps 5 percent (i.e., 3,600 cubic metres an hour).

If that same plant had no cooling tower and used once-through cooling⁸ water, it would require about 100,000 cubic metres an hour^[5] and that amount of water would have to be continuously returned to the ocean, lake or river from which it was obtained and continuously re-supplied to the plant. Furthermore, discharging large amounts of hot water may raise the temperature of the receiving river or lake to an unacceptable level for the local ecosystem. Elevated water temperatures can kill fish and other aquatic organisms (see thermal pollution). A cooling tower serves to dissipate the heat into the atmosphere instead and wind and air diffusion spreads the heat over a much larger area than hot water can distribute heat in a body of water. Some coal-fired and nuclear power plants located in coastal areas do make use of once-through ocean water. But even there, the offshore discharge water outlet requires very careful design to avoid environmental problems.

1. Industrial cooling tower – башенный охладитель

2. Power plant - электростанция

3. Petroleum refinery - НПЗ

4. Petrochemical plant – нефтехимическая установка

5. Processing plant – технологическая установка

6. Semi-conductor plant – полупроводниковая установка

7. Industrial facilities – промышленное оборудование

8. Once-through cooling Text №16 Reboiler

Reboilers¹  are heat exchangers typically used to provide heat to the bottom of industrial distillation columns². They boil the liquid from the bottom of a distillation column to generate vapors which are returned to the column to drive the distillation separation³.

Proper reboiler operation is vital to effective distillation. In a typical classical distillation column, all the vapor driving the separation comes from the reboiler. The reboiler receives a liquid stream from the column bottom and may partially or completely vaporize that stream. Steam usually provides the heat required for the vaporization. [

The most critical element of reboiler design is the selection of the proper type of reboiler for a specific service. Most reboilers are of the shell and tube heat exchanger⁴ type and normally steam is used as the heat source in such reboilers. However, other heat transfer⁵ fluids like hot oil or Dowtherm (TM) may be used. Fuel-fired furnaces⁶ may also be used as reboilers in some cases.

Commonly used heat exchanger type reboilers are:

Kettle reboilers

Kettle reboilers (Image 1) are very simple and reliable. They may require pumping of the column bottoms liquid into the kettle, or there may be sufficient liquid head⁷ to deliver the liquid into the reboiler. In this reboiler type, steam flows through the tube bundle⁸ and exits as condensate. The liquid from the bottom of the tower, commonly called the bottoms, flows through the shell side. There is a retaining wall or overflow weir⁹ separating the tube bundle from the reboiler section where the residual reboiled liquid (called the bottoms product¹⁰) is withdrawn, so that the tube bundle is kept covered with liquid.

1. Reboiler - ребойлер

2. Distillation column – ректификационная колонна, перегонный аппарат

3. Separation - разделение

4. Shell and tube heat exchanger – кожухо-трубчатый теплообменник

5. Heat transfer - теплопередача

6. Furnace -печь

7. Head - напор

8. Overflow weir - водослив

9. Tube bundle – трубный пучок

10. Bottoms product – недогон