Description

MANY TYPES OF ECONOMIZERS and recuperators

At Basaranlar Proses we engineer many types of economizers, recuperators or heat exchangers. For a boiler or steam generators fueled by natural gas, oil and biogas, both traditional tubes and finned tubes are applied depending on your production requirements. For a boiler fueled by coal, only regular tubes are optional due to the ash fouling.

Example industries for economizers and recuperators:

• Energy (power plant, combined heat and power (CHP), gas-fired, oil-fired, coal-fired and biomass-fired)

• Energy-from-Waste plants (household, hazardous, and hospital waste)

• Steel industry

• Oil and gas industry

• Pulp and paper industry

• Chemical industry

• Food industry

• Pharmaceutical industry

• Horticulture

Economizers and Recuperators provide many advantages:

• Increase in production process efficiency

• Reduced emission of CO2 and other toxic combustible wastes

• Lower energy consumption

• Reduced cost

• Suitable for all standard fuels

• Suitable for all waste heat and flue gas boiler types

• Easy retrofit into existing installations

• Short return on investment (commonly within 1 year)

At Basaranlar Proses, we build customized economizers and recuperators meeting your specific requirements. Please contact us for more information.

RECUPERATOR

Plate heat recovery recuperator units or tubular type recuperator are heat exchangers that allow the transfer of heat between two air flows under the action of a temperature difference. The use of such equipment allows significant savings on operating costs in air conditioning and therefore allows the recovery of energy, in the form of heat, which otherwise would be lost.

WASTE, EXHAUST OR FLUE GAS HEAT EXCHANGERS 

In cogeneration systems, waste, exhaust or flue gas is produced as a result of the combustion of gases such as natural gas and biogas in the gas engine. This gas is generally between 400 °C – 480 °C. It is possible to recover the energy in this gas by transferring it to water. In general applications, energy gain is achieved by cooling gases to around 180 °C.

One of the most important points in these exchanger designs is that the pressure loss of the gas in the exchanger is not desired to exceed 20 mbar.

These exchangers are generally designed in the NEN model. In this model, it is possible to reduce the tubesheet material thickness. The tubesheet is welded to the water side body and the gas side body. There are manhole covers the size of the body diameter on the gas sides for internal cleaning of the tubes. These covers are located on both sides. Sometimes, in order to reduce costs, the surfaces in contact with water are made of carbon steel material and painted with epoxy paint to provide protection against corrosion.

Expansion that will occur due to high temperature is provided by a compensator mounted outside the heat exchanger as standard.

Tubes are generally selected as AISI316 and have thicknesses between 1 mm and 1.5 mm. High H2S>200 ppm amount may cause corrosion problems in these exchangers.

In the example application, the gas flow rate is 6490 kg/h, the gas inlet temperature is 428 °C, and the gas outlet temperature is 120 °C. In the example application, the customer wants the water to have a 50% ethylene-glycol mixture to protect it from freezing. Water is prevented from freezing down to -36.5 °C. The water is heated from 85 °C to 95 °C. There is an energy gain of 639 kW in this heat exchanger design.

 

Sample Economizer application in Paper industry:

The data of the economizer we designed for one of Turkey’s largest paper producing companies is as follows.

The flue gas temperature is 110 °C and the flue gas flow rate is 141,750 Sm3/h. The inlet temperature of the water to be heated in the economizer is 60°C, the water flow rate is 157 m3/h and the desired water outlet temperature is around 70°C.

The total pressure loss of the flue gas in the economizer is not required to exceed 400 Pa.

According to the thermal calculations made, the desired thermal values are achieved at the outlet temperature of the flue gas at 75 °C.

                  

The gain to be obtained is a very high value of 1824 kW. Pipes and fins are made of stainless steel against corrosion. Precautions have been taken against corrosion by covering the carcass of the economizer with carbon steel material and the interior with stainless steel.

According to the design, the pipe length is 5700 mm, the product height is approximately 2500 mm and the depth is 1050 mm. When we add the hood dimensions at the entrance and exit, the depth measurement of the product will be greater than 1050 mm.

The heat transfer surface area increased to 2028 m2. Water side pressure loss is an acceptable value of 0.25 bar.