JPS6148978B2 - - Google Patents

Description

[Detailed Description of the Invention] This application is filed under Patent No. 1194789 (Patent Application No. 1975).
63376), which relates to an apparatus for regenerating an inorganic adsorbent other than activated carbon that adsorbs a carbon-containing substance using a fluidized bed reactor.

The fluidized bed reactor for the regeneration of activated carbon of the original patent invention comprises an upper reactor having perforated plates and placed above holding an activated carbon bed; A vertically movable submerged weir dividing the upper reactor into communicating upstream and downstream compartments; a lower reactor located below the upper reactor having a perforated plate and carrying an activated carbon bed; Furnace; a plurality of vertically movable submerged weirs immersed in the bed of activated carbon within said lower reactor and dividing said lower reactor into a series of communicating downstream compartments; means for feeding the upstream compartment of the furnace; provided at the end of the downstream compartment of the upper reactor for guiding activated carbon particles from the downstream compartment of the upper reactor to the downstream compartment of the lower reactor; Overflow weir; an overflow weir provided at the end of the last downstream compartment of the lower reactor for discharging regenerated activated carbon particles from the lower reactor; passing hot gas from below through the activated carbon bed means for collecting and condensing gases rising up an upstream compartment of the upper reactor, in communication with the upper reactor; and means for collecting and after-burning gases rising up the downstream compartment of the upper reactor, the two reactors having a length to width ratio. 2, and the immersion depth of the plurality of immersion weirs increases toward the overflow weir. We have discovered that it can be used to regenerate inorganic adsorbents, and have now completed the invention of a regeneration device for inorganic adsorbents other than activated carbon.

The fluidized bed reactor according to the invention is significantly simpler in construction than conventional multi-stage fluidized bed reactors with several superimposed inflow beds. The adjustable height of the immersion weir allows the residence time of the adsorbent to be adapted to changes in operating conditions, as required by changes in the type or concentration of adsorbed wastewater-containing substances. This is a major advantage of the present invention. Preferably, the immersion depth of the immersion weir is between 40 and 80% of the adsorbent filling height in the fluidized bed reactor.

Furthermore, the present invention is characterized in that the immersion depth of the plurality of immersion weirs in the lower reactor increases toward the adsorbent outlet, thereby increasing the moving speed of the adsorbent in the lower reactor. Since the speed is gradually increased and the speed is fastest at the outlet, the adsorbent desorbed in the upper reactor can be reactivated very efficiently in the lower reactor.

On the other hand, Japanese Patent Publication No. 49-1501 discloses the provision of a plurality of immersion weirs in a fluidized bed, but the immersion weirs described in this publication are of a fixed type and the immersion depth is limited to the extent that the adsorbent flow It differs from the immersion weir of the present invention in that it does not increase toward the outlet.

Another advantage of the present invention is that regeneration can be carried out in a two-stage fluidized bed reactor, in which case there are three or more stages (e.g. seven stages).
The advantage lies in the fact that it is possible to obtain product quality and yields that were previously possible only through the use of a fluidized bed reactor. Through the use of an adjustable submerged weir, the flow of the adsorbent from the adsorbent inlet to the adsorbent outlet can be achieved in such a way that a very uniform residence time of the adsorbent is achieved in the fluidized bed reactor. can. As a result of the uniform residence time, the regenerated adsorbent is in a nearly uniform regeneration state. Furthermore, due to the uniform residence time of the individual particles, the yield during regeneration is also very high, with losses per regeneration generally being less than 3%.

Inorganic adsorbents other than activated carbon that are regenerated in the apparatus of the invention are, for example, diatomaceous earth, silicic acid gel, or aluminum oxide, and the adsorbents are in the form of pellets or granules. The regeneration of inorganic adsorbents other than activated carbon in fluidized bed reactors according to the invention is simply adapted to the varying relationships of gasifying agent, temperature range and residence time. For example, in the case of the regeneration of aluminum oxide with adsorbed substances from pulp industry wastewater, when air is used as gasifying agent, at temperatures between 500 and 600 °C 0.2 to 0.8
A residence time of hours is sufficient. Of course, in that case,
The flow velocity of the fluidized bed must be set such that the aluminum oxide remains suspended.

Another advantage of the fluidized bed reactor according to the invention consists in that, due to the rapid removal of the combustion heat generated, it is impossible for too high a temperature to build up inside the adsorbent grains. The method using this device prevents a change in crystal state or transition to other crystal modifications in the regeneration of inorganic adsorbents other than activated carbon. Therefore, the regenerated adsorbent is advantageous in that it has an activity that is very close to that of the new adsorbent.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fluidized bed reactor according to the present invention and its operating method will be explained in detail below with reference to the drawings.

According to FIGS. 1 and 2, a second fluidized chamber 11 is arranged above the aforementioned fluidized chamber 4 in the fluidized bed reactor. The moist inorganic adsorbent other than activated carbon to be regenerated is first introduced into the fluidized bed 11 above the fluidized bed reactor 2 via the inlet pipe 1 and the conical mounting 3. The adsorbent is immersed weir 1
2 and the drop pipe 1 after passing through the adjustable overflow weir 13
4 into a fluidized bed 4 where the adsorbent undergoes further processing. The plurality of immersion weirs 6 can be moved up and down within the fluidized bed 4, and the immersion depth gradually increases toward the outlet. By this method the desorption zone and the reactivation zone are separated from each other. Fluidized gas is produced in the combustion chamber 15,
First, it flows through the inflow bottom 5 and the fluidized bed 4, and then through the inflow bottom 10 and the fluidized bed 11. Here too, the waste gas is fed through a gas hood 16 for condensation and through a gas hood 17 to the afterburner. The regenerated adsorbent is sent through the overflow weir 8 to the outlet 7 and further to the adsorbent reservoir 9.

Approximately 800 ^m3 of inorganic adsorbent other than activated carbon was used to purify 210 m3 of pulp wastewater (TOC = 450 g/ ^m3 ).
Kg/h of Al ₂ O ₃ (particle size 1.5-2.5 mm) was used.

The regeneration of Al ₂ O ₃ after being used for adsorption treatment is the first step.
The experiment was carried out in the two-stage fluidized bed reactor shown in the figure. The lower stage of this two-stage reactor has a length of 2.2 m and a width of 0.55 m, and the upper stage is 1.8 m.
had the same length and width as the stage below.
Three immersion weirs were arranged in the lower fluidized bed at intervals of 0.55 m, and the distance between the immersion weirs and the bottom of the fluidized bed was 0.1 m. The overflow weir is 0.15m and 0.55m.
Continuous height adjustment is possible between m. In the case of this playback experiment, it was adjusted to 0.410 m. A similar immersion weir is placed 0.6 m away from the front wall (stirnwand) on the entrance side in the length direction of the upper stage.
The distance between the immersion weir and the bottom of the fluidized bed was 0.15 m. The height of the overflow weir can be adjusted steplessly between 0.5m and 0.55m. 0.55 in the case of this playback experiment
It was adjusted to m.

The overflow passage from the upper stage to the lower stage is immersed in the lower fluidized bed and is 0.1 m below the bottom of the lower fluidized bed.
It extends to the height of.

The total amount of waste gas was approximately 1600 m ³ n/h, but at that time approximately 1000 m ³ n/h at approximately 150°C was introduced into the condensing equipment.
The remainder of the average 300°C reaches the after-combustion directly. The fluidized gas is obtained by burning city gas in an air surplus and first passes through the lower fluidized bed, whereby the Al ₂ O ₃ present there is heated to about 550°C. The fluidized gas then passes through the upper fluidized bed, and the Al ₂ O ₃ after being used for adsorption treatment is dried in the front part of the fluidized bed and preheated to about 300 °C in the latter part. .

The purity of Al ₂ O ₃ treated in this way is novel
It was the same as that of Al ₂ O ₃ and the adsorption capacity was also similar. Furthermore, there was no material loss during regeneration.

Additional relationship The original patent, Patent No. 1194789 (Japanese Patent Application 1973-
The fluidized bed reactor of the invention of No. 63376) is used to thermally regenerate activated carbon that has adsorbed wastewater-containing substances. Since the present invention can be used as it is to regenerate the adsorbent, the main parts of the present invention are the same as the original patented invention, and the patent law applies to the original patented invention as an invention for achieving the same purpose (regenerating the adsorbent). The requirements stipulated in Article 31, Paragraph 1, Item 1 are met.

[Brief explanation of the drawing]

FIG. 1 shows an overall longitudinal cross-sectional view of a two-stage fluidized bed reactor, and FIG. 2 shows a plan view of the fluidized bed reactor shown in FIG. Explanation of main symbols in the drawings, 1: Inflow pipe, 4, 1
1: fluidized bed, 5, 10: inflow bottom, 6, 12: immersion weir, 7: outlet, 8, 13: overflow weir, 15: combustion chamber, 16, 17: gas hood.

Claims (1)

[Claims] 1 an upper reactor located above, having a perforated plate and holding an adsorbent bed 11; an upstream compartment and a downstream compartment immersed in the adsorbent bed 11 in the upper reactor and communicating with each other; a vertically movable immersion weir 12 dividing the upper reactor; a lower reactor located below said upper reactor having a perforated plate and holding an adsorbent bed 4; A plurality of vertically movable submerged weirs 6 immersed in the adsorbent bed 4 and dividing the lower reactor into a series of communicating downstream compartments; transferring the adsorbent particles to be regenerated to the upstream compartment of the upper reactor; Means for feeding the chamber 1; an overflow provided at the end of the downstream compartment of the upper reactor for guiding adsorbent particles from the downstream compartment of the upper reactor to the downstream compartment of the lower reactor; Weir 13; overflow weir 8 provided at the end of the last downstream compartment of the lower reactor for discharging regenerated adsorbent particles from the lower reactor; hot gas from below to the adsorbent bed 4 and then through said adsorbent bed 11;
means for collecting and condensing gases rising up an upstream compartment of the upper reactor, in communication with the upper reactor; and in communication with the two reactors;
comprising means for collecting and after-combusting gases ascending downstream compartments of said upper reactor, said two reactors having a length to width ratio greater than 2; and said two reactors having a length-to-width ratio greater than 2; A regeneration device for an inorganic adsorbent other than activated carbon, characterized in that the depth increases toward an overflow weir 8.