Why should the chimney be raised? -Huaqiang Electronic Network

chimney

Why do you want to increase?

The higher the chimney

,

The better the smoke exhausting ability

""

The higher the air pressure, the smaller

”

These two sentences are correct, but the higher the chimney, the better the smoke exhausting ability is not because the higher the air pressure is, the smaller the air pressure is. If it is really caused by this reason, let alone the air in the chimney will go up by itself. The air on the ground also ran all up, haha! Let me explain why.

Any object in the atmosphere (including the air itself) will be subject to buoyancy from the air, but why is the air still balanced (without considering the blowing phenomenon) without floating up? That's because the air is not only lifted up, but also by its own gravity. Usually, the buoyancy of the air is equal to the downward gravity of the air, so it maintains the balance.

However, the smoke emitted from the chimney is hot air with a very high temperature. The higher the temperature, the more the temperature rises, and the gravity per unit volume becomes smaller. The buoyancy does not change, and the gravity of the hot air becomes smaller. So, the cigarettes will float up and go up. When the temperature rises, the smoke will spread horizontally. If you are in the windless (preferably early morning and evening), stand on the mountain in the countryside. Looking at the fireworks of the farmers in the ravine, you can see this phenomenon, very spectacular.

Why do chimneys have to be high, because the higher the chimney, the more hot air the chimney has, the greater the total buoyancy it receives, the greater the pressure generated by buoyancy, and the stronger the ability to smoke. Is it not to make the chimney not to be tall but to make it bigger? Of course not. If you only make the chimney bigger and not taller, the buoyancy of the cigarette will also increase, and it will be proportional to the increased cross-sectional area, but the pressure is strong.

=

pressure

/

The area of ​​the force, the pressure and the area are proportionally larger, the pressure does not change, and the suction at the lower part of the chimney does not become large. The reason and the lift of the pump are only related to the vertical height of the water pipe, and The horizontal distance has nothing to do with it.

In addition, the chimney is tapered only because of the need of the building, and does not help the ability to smoke. The chimney is not the higher the better, the chimney has an optimal height, depending on your smoke output and chimney diameter. When the smoke volume and caliber are certain, the chimney exceeds a certain height and then high. It makes no sense.

The height of the chimney has an impact on the ability to smoke

But the key is not this

The key is that the chimney should be made into a conical shape.

In this way, the air pressure in the chimney is much larger than the air pressure outside the chimney.

The better the smoke extraction capacity of the chimney

The chimney is raised

,

Able to form a better temperature gradient

,

The thermal expansion of air is better

.

Product summary indicator:

1

High temperature resistance:

250

°C.

2

, dilute acid (sulfuric acid, nitric acid, hydrochloric acid)

5%

concentration,

80

°C temperature:

12

No change in the day;

Resistant

30%

sulfuric acid:

80

°C

15

No change in day, normal temperature

30

There is no change in the day.

3

,

Water resistance: soaking at room temperature

90

There is no change in the day.

4

Resistant to peeling: (quick and hot

250

°C

/

Water-cooled repeated cycles)

50

No change.

5 .

Anti-aging index: heat and humidity resistance test

500h

No change.

6.

Maximum service life:

13

year.

7

Construction period:

20-30

day.

Single cylinder

chimney

Conversion of lining desulfurization (new chimney lining treatment) and acid chimney treatment of steel chimney:

(1) Old chimney to lining renovation and new single-tube chimney lining treatment:

1

, treatment methods and procedures: sweeping ash cleaning (new chimney without this procedure), brush

OM

Interface agent

OM

Putty, brush

OM-4

Two bottom materials, the last brush

OM-5

Chimney resistant high temperature acid and anticorrosive coating two (in the middle can be added glass cloth

1―2

Total thickness

1.5―2.0mm

.

2

,Construction period:

20

day(

210-240M

chimney).

(2) The anti-corrosion treatment plan for the inner side of the steel chimney:

1

, processing methods and procedures: brush after rust removal

OM-4

Two bottom materials, brush

OM-5

Chimney resistant high temperature acid and anticorrosive coating two, total dry film thickness

0.5―1.0mm

. (Design Institute chooses thickness according to needs)