JPH0334241Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a novel structure of a bubble cap used in a bubble cap type tray.

[Prior Art and Problems] For purification and recovery of various organic solvents, recovery of ammonia from ammonia-containing liquid, etc., tray-type distillation columns and rectification columns (hereinafter collectively referred to as these) having bubble cap trays are used. distillation columns) are often used.

In the tray type distillation column as described above, an increase in the amount of entrainment (entrainment) not only causes a decrease in the plate efficiency of the distillation column, but also when recovering ammonia from the ammonia-containing solution as described above. Scale components generated by the reaction between calcium hydroxide added to liberate carbonate ions, sulfate ions, etc. present in the liquid are entrained in the droplets and adhere to the gas passage holes in the upper tray. This results in increased pressure drop in the column.

BACKGROUND ART Conventionally, in order to reduce the amount of entrainment in a tray distillation column having a bubble cap, a bubble cap having a structure in which a plurality of slots are provided at the bottom has been known. That is, by providing a plurality of slots, it is possible to blow out gas uniformly over the entire circumference of the bubble cap, thereby increasing the effect of reducing the amount of entrainment due to gas-liquid contact.

However, the bubble cap provided with the above-mentioned slots does not have a sufficient effect of preventing entrainment gas from blowing through, and as the speed of the cylinder inside the column increases, the amount of gas blowing through increases, and the amount of entrainment gas increases. There is also a problem that the amount of water increases significantly.

[Means for Solving the Problems] As a result of intensive research to solve the above problems, the inventors of the present invention have found that the gas blown out from the slot of the bubble cap causes the liquid on the tray to flow onto the wall of the bubble cap. I discovered a phenomenon in which the air blows up as the air blows up. Based on this knowledge, by providing a collar under certain conditions on the slot of the bubble cap and the outer periphery above the clarified liquid level, the liquid that blows up along the wall of the bubble cap is scattered in a film. The present invention was proposed after confirming that a thin film can extremely effectively collect droplets in gas and, in turn, significantly reduce the amount of entrainment.

The present invention is a bubble cap used in a bubble cap type tray, and includes a slot provided at the bottom of the outer periphery of the cap and a horizontal surface located above both the clarified liquid surface on the tray during use. This bubble cap is characterized by having an upward flange with an elevation angle of 30 to 70 degrees.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to these drawings. FIG. 1 is a sectional view showing a typical embodiment of the bubble cap of the present invention.

In the present invention, the flange 2 is used to scatter the liquid that blows up along the outer wall of the bubble cap 1 from the slot 3 into a thin film around the bubble cap 1. In order to perform this function, the flange 2 As shown in FIG. 2 showing the usage state of the bubble cap 1 , the bubble cap 1 is located above both the slot 3 provided at the lower part of the outer periphery of the bubble cap 1 and the clarified liquid level on the tray 4 during use. It is installed at the position of That is, by providing the collar 2 on the outer periphery of the bubble cap, which is located above both the slot 3 and the clarified liquid level on the tray 4 during use, the liquid that blows up along the outer wall of the bubble cap 1 can be prevented. The liquid film 6 can be formed by scattering it in a thin film around the bubble cap 1 , and the droplets contained in the gas can be collected by the liquid film 6 to reduce the amount of entrainment even when the gas amount increases. can be effectively reduced.

In addition, the manner in which the flange 2 is attached to the outer periphery of the bubble cap 1 is such that the flange 2 faces upward and has an elevation angle of 30 to 70 degrees, and more preferably 35 to 65 degrees, with respect to the horizontal plane. This is preferable in order to effectively reduce the amount of entrainment.
Further, the width of the flange 2 is not particularly limited, but the width W of the tsuba 2 is 0.5L to 4L, preferably 2L to 3L, relative to the distance L from the upper end of the slot 3 to the attachment position of the flange 2. It is preferable to determine this in order to further reduce the amount of entrainment. Furthermore, it is generally preferable that the length L be 15 to 25% of the distance from the top of the slot 3 to the top of the bubble cap 1 .

The shape of the flange 2 described above may be flat as shown in the figure, or may be curved or bent from the attachment portion toward the outer periphery. Also, Tsuba 2
In order to form a continuous film of liquid around the bubble cap 1 , it is most preferable to have a continuous structure over the entire circumference, but it may be divided into a plurality of locations with gaps.

In the bubble cap of the present invention, other structures,
For example, the shape and size of the slot 3, the shape and size of the bubble cap body, etc. are not particularly limited, and any known structure may be employed without particular limitation.

Further, the bubble cap of the present invention may be used in the same manner as known bubble caps. Figure 2 shows a bubble cap 1 according to the present invention on tray 4 .
This is a cross-sectional view of the installed state. Generally, the bubble cap 1 is provided so that the slot 3 is located at a lower position than the upper end of the gas passage hole 5 of the tray 4 . Moreover, it is most preferable that the bubble cap 1 is provided so that the collar 2 is at a height near the upper end of the gas passage hole 5.

[Functions and Effects] The bubble cap 1 of the present invention causes the liquid accompanying the gas blown out from the slot 3 through the gas passage hole 5 of the tray 4 to be scattered by the flange 2 and form a liquid film 6.
form. Since droplets contained in the gas are collected by the liquid film 6, the amount of entrainment can be effectively reduced even when the amount of gas increases.

Therefore, the stage efficiency of the distillation column can be dramatically improved, and the formation of scale can be effectively prevented in the recovery of ammonia as described above.

Incidentally, instead of the bubble cap of a tray distillation column with a conventional bubble cap, a slot is installed at a position of 20% of the distance from the top of the slot to the top of the bubble cap at an angle of 45 degrees to the horizontal plane. When using the bubble cap of the present invention, which has a collar with a width of 2L for the distance L from the top end to the mounting position, the amount of entrainment can be reduced by more than 90%.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a typical embodiment of the bubble cap of the present invention, and FIG. 2 is a cross-sectional view showing the bubble cap of the present invention attached to a tray. In the figure, 1 is a bubble cap, 2 is a tsuba, and 3 is a bubble cap.
4 is a slot, 4 is a tray, 5 is a gas passage hole, and 6 is a liquid film.

Claims (1)

[Scope of utility model registration request] A bubble cap used in a bubble cap type tray, which has a slot at the bottom of the outer periphery of the cap and a position above both the clarified liquid level on the tray when in use and has a diameter of 30 to 30 mm with respect to the horizontal plane. A bubble cap characterized by an upward flange with an elevation angle of 70 degrees.