What Is Air Preheater Design And Features?

- Apr 02, 2018-


序号NO.

项目

Project

单位

Unit

介质名称

Mediuum

设计工况

Design condition

1

体积流量

Flow rate

NM3/h

烟气

Flue gas

20000

空气

Flue gas

14000

2

进口温度

Inlet temperature

烟气

Flue gas

350

空气

15

3

出口温度

Outlet temperature

Air

烟气

148

Flue gas

空气

311

4

阻力降

Resistance Drop

Pa

Air

烟气

258

Flue gas

空气

347

5

最高壁温

Max pipe wall temperature.

Air

301

6

最低壁温

Min pipe wall temperature.


144

7

回收热量

Recuperated heat

KW


1349


Application of Heat Pipe Air Preheater in Waste Heat Recovery of Blast Furnace Hot Blast Furnace.


The heat pipe heat exchanger is a new type of high-efficiency heat exchanger, which has been widely used in the preheating of blast furnace air and gas in the metallurgical industry, waste heat recovery of the rolling mill heating furnace and sintering machine.

The preheating of the air by the heat pipe heat exchanger is used to increase the air temperature of the hot blast stove, thereby reducing the cost of the blast furnace smelting. This article describes the design and structural characteristics of air preheaters.


Features


The heat pipe air preheater is high in heat transfer.


The heat exchange between the flue gas and the air is performed on the outer surface of the heat pipe, and the outer surface of the heat pipe is finned to increase the heat exchange area and enhance the heat transfer; the cross flow of the traditional air preheater is changed to pure countercurrent flow, increasing the transmission Hot and warm pressure; Secondly, the internal flow of flue gas is changed to flow outside the tube, so that the heat transfer coefficient is improved and the heat transfer performance is superior. In addition, its small size, compact structure, reduce the amount of steel.


There is no leakage in the heat pipe air preheater.


The hot and cold fluids are separated by partitions so that there is no leakage between the flue gas and the air. At the same time, each heat pipe is completely independent, even if one or more of the heat pipes are damaged or failed, it will not affect the work of other heat pipes and will not cause air leakage and ash leakage.


Anti-adhesion, ash blocking, strong corrosion resistance


The temperature of the pipe wall is adjusted by adjusting the size of the extended heating surface of the hot and cold section of the heat pipe, so that it is higher than the dew point temperature or the maximum corrosion zone. Since the wall temperature is higher than the dew point temperature, the dust on the outer surface of the attached heat pipe is dry and loose. The dust is easy to fall off, and the air flow rate of the heat pipe air preheater is set to 8-10 m/s, which can avoid clogging and greatly reduce wear.


Good sealing performance between separator and heat pipe 


A sealing collar with a special sealing structure is welded on the heat pipe, and a flexible graphite sealing ring is installed in the sealing sleeve. This kind of fluid sealing product made of pure natural graphite. It has flexibility, compressibility, deformation consistency and resilience. Can be made into a variety of shapes and sizes to meet a variety of fluid sealing applications, is an excellent sealing material.


Dust removal measures


Because the smoke contains a certain amount of dust, the long-term operation of the equipment will cause the heated area of the flue gas to be ash, which will affect the heat transfer performance of the equipment. Therefore, sonic cleaning is used for cleaning. The air source is compressed air. This type of dust remover has a good cleaning effect for dry dust accumulation, and it consumes less gas and requires less daily maintenance. The principle of the high-efficiency sonic clearer is to send sound waves of a certain intensity into the space of various possible ash deposits and slags in the heat exchanger body in operation. Through the action of sound energy, the air molecules and dust in these areas are made to work. The particles oscillate, destroy and prevent the binding of dust particles on the heat exchanger surface or between the particles, and are always in a suspensible fluidized state so as to be carried away under the influence of smoke and gravity.


http://www.vrcoolertech.com/industrial-air-cooler/dry-cooler/air-preheater.html