JPS5912339B2 - How to reduce pressure loss in suspension preheater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reducing the pressure loss of a suspension breaker in existing equipment for firing powder raw materials such as cement and alumina.

Suspension preheater kilns have traditionally been widely used as firing equipment for cement raw materials, but in recent years, suspension kilns with a calciner, in which the suspension preheater is equipped with a calciner, have been increasingly used. .

This is intended to increase the specific firing rate of the kiln by having the calciner share part of the heat load of the kiln.

In other words, in recent years, firing equipment that does not have a calciner has become obsolete, so disposing of the old firing equipment and installing a new one with a calciner would require enormous construction costs. Since it requires a long construction period and is not a good method, most of the existing filling equipment can be used as is, and a suspension breech heater with a calcination furnace can be constructed by modifying a very small part of the suspension breaheater by installing a new calcination furnace. It is hoped that it will be renovated.

However, adding a calcining furnace to existing firing equipment increases the pressure loss within the system.

In addition, increasing the capacity will also increase the pressure loss within the system, and this increase in pressure loss will exceed the capacity of the existing main exhaust fan, so the existing main exhaust fan cannot be used as is. Therefore, it will have to be replaced with a new main exhaust fan with larger capacity.

The present invention allows the existing main exhaust fan to be used as is when there is an increase in pressure loss that exceeds the capacity of the existing main exhaust fan due to the above-mentioned modification or improved capacity of the existing firing equipment. In order to reduce the pressure loss between the gas inlet of one cyclone and the outlet of that cyclone, we can reduce the pressure loss between the gas inlet of one cyclone and the outlet of that cyclone by installing a new small-diameter cyclone in parallel with an appropriate number of cyclones in the existing suspension breheater. This is designed to reduce the amount by the increase in loss.
One embodiment thereof will be described with reference to the drawings.

In the drawing, 1 is one cyclone in the existing suspension breaker heater, 2 and 3 are the lower cyclones and further lower cyclones, 4 is the main exhaust fan, and 5 is the connection between the inlet of the cyclone 1 and the gas outlet of the cyclone 2. 6 is a connecting duct connecting the inlet of the cyclone 2 and the gas outlet of the cyclone 3; 1 is an exhaust duct connecting the gas outlet of the cyclone 1 and the main exhaust fan 4; , 8 is a powder raw material supply device, 9 is its raw material chute, 10
11 is a connecting portion of the chute 9 to the connecting duct 5, and 11 is a raw material chute connecting the raw material outlet of the cyclone 1 and the connecting duct 6, which are already installed.

A small-diameter cyclone 12 is newly installed in the existing cyclone 1 configured as described above, and the inlet of the newly installed cyclone 12 is connected to the raw material of the connecting duct 5 which is the gas outlet duct of the cyclone 2. Shoot 9
connected by a newly installed inlet duct 13 above the connection part 10 of
Furthermore, the gas outlet of the newly installed cyclone 12 is connected to the exhaust duct 1, which is the gas outlet duct of the corresponding cyclone 1, through the newly installed gas outlet duct 14, and the raw material outlet of the newly installed cyclone 12 is connected to the exhaust duct 1, which is the gas outlet duct of the corresponding cyclone 1. A new raw material chute 15 is connected to the duct 6 to which the raw material chute 11 of the cyclone 1 is connected.

By doing this, the newly installed small-diameter cyclone 12 is placed in parallel with the cyclone 1.

That is, the gas from the cyclone 2 passes through the connecting duct 5, flows to the cyclone 1, and then to the exhaust duct 7, but a portion of the gas is also extracted from the connecting duct 5 by the newly installed inlet duct 13, and is transferred from the newly installed cyclone 12 to the newly installed cyclone 12. The gas flows to the gas outlet duct 14 and merges at the exhaust duct γ.

The powder raw material supplied from the raw material chute 9 to the connecting duct 5 also flows from the connecting duct 5 to the cyclone 1, and from the raw material chute 11 to the connecting duct 6.
Further, a part of the raw material is extracted from the connecting duct 5 by the newly installed inlet duct 13, flows from the newly installed cyclone 12 to the newly installed raw material chute 15, and joins at the connecting duct 6.

Therefore, by newly installing the small-diameter cyclones 12 in parallel, the cross-sectional area of the flow path increases accordingly in this part.

In other words, the gas containing the powdered raw material is transferred to the newly installed cyclone 12.
Since the flow is diverted to cyclone 1, from the perspective of cyclone 1, the flow rate is reduced by the amount of flow diverted to the new cyclone 12. Therefore, the gas processed by this cyclone 1 is lower than in the existing state without the new cyclone 12. The flow velocity becomes slower, and the pressure loss decreases in proportion to the square of this slower velocity.

The cyclone 12 may be selected so that this reduction in pressure loss compensates for the increase in pressure loss due to remodeling and capacity improvement of existing equipment.

In order to reduce the pressure loss while preventing a decrease in dust collection efficiency, it is most effective to newly install a small-diameter cyclone 12 in parallel with the uppermost cyclone 1, as shown in the figure.

It is also possible to reduce the pressure loss by changing the shape of the entrance and exit of the existing cyclone or the shape of the inner cylinder of the cyclone, but such a method is not preferred because it may lead to a decrease in dust collection efficiency.

As mentioned above, the present invention provides a method for installing an appropriate number of cyclones in an existing suspension breheater when there is an increase in pressure loss that exceeds the capacity of the existing main exhaust fan due to modification of the existing firing equipment and improvement of its capacity. By installing new small-diameter cyclones in parallel to reduce the pressure loss between the inlet of one cyclone and the outlet of one cyclone, the existing main exhaust fan can be used as is without replacing it. Moreover, the dust collection efficiency is not reduced, the construction cost is significantly reduced, and the construction period is also shortened.

Additionally, the new cyclone needs to be small in diameter, making construction extremely easy.

[Brief explanation of the drawing]

The figure is an elevational view of one embodiment of the invention. 1...One cyclone, 2...Lower cyclone, 3...Further lower cyclone, 4...Main exhaust fan, 5, 6... ...Connection duct, γ...Exhaust duct, 8...Powder raw material supply device, 9...Raw material chute, 10...
... Connection part, 11 ... Raw material chute, 12
...Newly installed cyclone, 13... Newly installed inlet duct, 14... Newly installed gas outlet duct, 15
・・・・・・New raw material chute.

Claims (1)

[Claims] 1. In powder raw material firing equipment, when modifying a part of the existing suspension breheater or improving its capacity, if there is an increase in pressure loss that exceeds the capacity of the existing main exhaust fan, the existing main exhaust fan shall be replaced. Leave it as it is, install a small diameter cyclone in parallel with the appropriate number of cyclones in the existing suspension breheater, and place the inlet of the parallel cyclone in the upper position than the raw material chute connection of the gas outlet duct of the cyclone located at the lower stage. The pressure loss of the existing cyclone is reduced by connecting the gas outlet to the gas outlet duct of the cyclone and the raw material outlet to the inlet duct of the lower cyclone to which the raw material chute of the cyclone is connected. The special mission is to reduce the pressure loss by an amount equivalent to the increase in pressure loss due to the modified parts or the increase in pressure loss due to improved capacity.