JPH0140653B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adsorbent manufacturing apparatus for manufacturing an adsorbent used to separate oxygen and nitrogen in the air by adsorption. Naturally occurring tuff that has been heat-treated and dehydrated has a selective absorption property for nitrogen, and a method is already known that utilizes this property to separate oxygen and nitrogen in the air. (For example, Japanese Patent Publication No. 54-22428). In order to use this separation method, the collected tuff must be crushed to an appropriate particle size and then heated to a temperature of 350°C or higher and 700°C or lower to remove the water contained in the rough stone particles, that is, bound water. This is necessary, and adsorption activity can only be imparted through such heat treatment in a calcining furnace. In this heat treatment, when the temperature of the rough stone is below 350°C, bound water is not removed, and when it is above 700°C, decomposition occurs, resulting in a significantly lower adsorption in both cases. Furthermore, when the dehydrated product comes into contact with the atmosphere, it absorbs moisture from the atmosphere due to its strong hygroscopicity and rapidly loses its catalytic activity. However, in conventional adsorbent manufacturing equipment, when attempting to cool an adsorbent intermediate product that has been fired in a firing furnace and from which bound water has been removed in a cooling tank, the configuration is such that cooling air is simply circulated around the cooling tank. Therefore, in the process of cooling the heated adsorbent intermediate product with cooling air, the humidity gradually increases in this circulation flow path. Therefore, in order to obtain an adsorbent with excellent adsorption function, it is necessary to eliminate the influence of moisture absorption of the adsorbent intermediate product during this cooling process. Possible ways to do this include, for example, cooling gradually over a long period of time, or adding a large-scale device just for moisture absorption, but in any case, it is difficult to reduce productivity and cost. It cannot be said that it is preferable in terms of aspects. The present invention has been made in view of the above circumstances, and provides an adsorbent manufacturing apparatus that can effectively prevent moisture absorption during the cooling process with a simple configuration and can manufacture an adsorbent that has excellent adsorption performance. It is intended to. Next, an embodiment of the present invention will be described with reference to the drawings. In the figure, hopper 1, firing furnace 2
The cooling tanks 3 and 3 are connected in series in this order and are supported by appropriate support members (not shown) so that their axes are perpendicular. Further, below the hopper 1, the firing furnace 2, and the cooling tank 3, there are provided shutters 4, 5, and 6 that are opened when discharging the contents. Furthermore, the heating tank 7 is for supplying high-temperature air at a predetermined temperature into the firing furnace 2. This heating tank 7 and firing furnace 2 are preferably covered with a heat insulating material 8. Natural tuffs used as adsorbent raw materials are produced, for example, in the Tohoku region (near Minase Village, Ogatsu District, Akita Prefecture) and the Chugoku region (near Nima Town, Kusuma District, Shimane Prefecture), and are listed in Tables 1 and 2. Examples include those having an X-ray diffraction pattern as shown.

【table】

【table】

【table】

[Table] After the natural tuff described above is crushed to an appropriate particle size, it is put into hopper 1,
With the shutter opened, a predetermined amount is supplied into the firing furnace 2, and then the shutter 4 is closed. In this example, approximately 800 raw stones are stored in the firing furnace 2.
On the other hand, air sent from the blower 9 is heated in the heating tank 7 and then sent into the firing furnace 2. Heating tank 7
has the ability to supply air at about 600° C. into the firing furnace 2 at a flow rate of 400 to 600 m ³ /hr. This heated air heats the rough stone while moving downward through the particles of the rough stone housed in the firing furnace 2, and after removing its bound water, the air is discharged from the exhaust gas formed at the lower end of the firing furnace 2. It is released from the hole 10 to the outside. This firing process is completed in 6 to 8 hours, although it varies somewhat depending on the type of raw stone and moisture content. The calcined tuff particles, which serve as an adsorbent intermediate product, exhibit extremely high hygroscopicity because they are almost completely deprived of bound water, and therefore, when brought into contact with the atmosphere in this state, they immediately absorb moisture. and lose adsorption activity. In this invention, in order to cool the fired particles without contacting them with the atmosphere, the shutter 5 is opened and the particles in the firing furnace 2 are transferred to the cooling tank 3, where they are brought into contact with highly dried air. The structure is such that it can be done. That is, inside the cooling tank 3, there is a pipe 1 provided at the bottom of the cooling tank 3.
Dry air used as cooling air is introduced from 1 (air inlet), and the air that has passed between the fired particles is passed through pipe 12 (air outlet) provided at the top.
It is now being discharged from the The pipes 11 and 12 have circulation pipes 19 and 20 leading to the cooling tower 15 and the blower 16, respectively.
A circulation pipe 21 is connected between the cooling tower 15 and the blower 16. In other words, the circulation pipe 20, the cooling tower 15, the circulation pipe 21, the blower 1
6. The ends of the cooling air circulation path formed by the circulation pipe 19 are connected to the pipe 12 and the pipe 11, respectively. Among these cooling air circulation channels, the pipe 12
In the part near the circulation pipe 20, the first and second drying towers 13 and 14 are connected to the valve 2, respectively.
2 and 23, and this drying tower 1
3 and 14, a compressor 1 is provided as supplementary cooling air supply means through valves 24 and 25, respectively.
7 is connected. Note that the valves 26 and 27 are for attaching and detaching, which will be described later. A compressor 1 is installed inside the drying towers 13 and 14.
It is filled with an adsorbent that dries the supplementary cooling air supplied from 7. Since this adsorbent needs to have an excellent adsorption function, it is preferable to use an adsorbent produced according to the present invention. Next, in the adsorbent manufacturing apparatus configured as described above, an operation will be described in which the particles stored in the cooling tank 3 from the firing furnace 2 without being exposed to the outside air are cooled by cooling air. The air taken out from the cooling tank 3 via the pipe 12 and the circulation pipe 20 has a high temperature due to contact with the high temperature particles in the cooling tank 3.
After this air is cooled by passing through the cooling tower 15, the air is cooled by the action of the blower 16, and then the circulation pipe 1
9 and pipe 11 and then returned to the cooling tank 3. During this circulation process, the dry air becomes more humid, so some of it must be vented by opening the valve 18. Therefore, it is necessary to replenish cooling air using the compressor 17, but for this purpose, either the drying towers 13 or 14 must be used to adsorb this replenishment cooling air. In other words, in the case shown in the figure (showing the case where the drying tower 13 has already adsorbed and then the drying tower 14 is functioning), the valve 24 is closed on the drying tower 13 side, and the valves 22 and 26 are open. On the drying tower 14 side, valves 25 and 23 are open, and valve 27 is closed. Therefore, all the supplementary cooling air from the compressor 17 is guided into the drying tower, adsorbed by the internal adsorbent, and the circulation pipe 23 is replenished with dried air. At this time, since the valve 22 is open, air heated by the particles in the cooling tank 3 is introduced into the drying tower 13. The introduced air is discharged to the outside from the valve 26 after desorbing the adsorbent in the drying tower 13, which has already performed a sufficient adsorption action and whose adsorption function has deteriorated. In other words, the adsorption function of the adsorbent in the drying tower 13 is restored to its original state by utilizing the air discharged from the cooling tank 3. Then, when the adsorption function of the adsorbent in the drying tower 14 gradually decreases, the valves 22 to 27 are operated in the opposite state to the above, and this time, using the drying tower 13, Supplementary cooling air from the compressor 17 may be supplied to the circulation pipe 20. In this way, by alternately using the first drying tower 13 and the second drying tower 14, it is possible to always supply sufficiently dried supplementary cooling air, thereby effectively cooling the particles in the cooling tank 3. It can be done in a specific manner. In the above embodiment, the dry air supplied from the pipe 11 into the cooling tank 3 has a dew point of -70 to -
Air at a temperature of 65° C. and 40° C. was used at a flow rate of about 100 m ³ /hr, and the time required to cool the particles in the cooling tank 3 to about 45° C. was about 8 hours. After the particles in the cooling tank 3 are dried to a predetermined temperature, they are discharged by opening the shutter 6 and stored in a closed container so as not to come into contact with air. Preferably, the closed container is filled with nitrogen. As described above, according to the present invention, when an adsorbent raw material such as natural tuff is calcined and an adsorbent intermediate product is cooled in a cooling tank, the first and second drying towers are alternately used to thoroughly dry the adsorbent raw material. Since the supplementary cooling air can be efficiently supplied, moisture absorption of the adsorbent intermediate product in the cooling process can be effectively prevented with a simple configuration, and an adsorbent having a high adsorption activity function can be obtained.

[Brief explanation of drawings]

The figure is a schematic configuration diagram showing an adsorbent manufacturing apparatus according to an embodiment of the present invention. 1... hopper, 2... kiln, 3... cooling tank,
11... Pipe (air inlet), 12... Pipe (air outlet), 13... First drying tower, 14...
Second drying tower, 17... Compressor (supplementary cooling air supply means), 19, 20, 21... Circulation pipe.

Claims (1)

[Claims] 1. A firing furnace for firing the adsorbent raw material supplied from the hopper, a cooling tank for storing the adsorbent intermediate product sent from the firing furnace without being exposed to outside air, and an air inlet and an air outlet of the cooling tank. A first cooling air circulation passage connected to the air outlet and a cooling air circulation passage near the air outlet each separately connected to the cooling air circulation passage and filled with a supplementary cooling air drying adsorbent.
and a second drying tower, and supplementary cooling air supply means for supplying supplementary cooling air to the cooling air circulation passage through either the first or second drying tower, and the first drying tower. and the second drying tower, while one is drying the supplementary cooling air,
The other one is an adsorbent manufacturing apparatus characterized in that the reduced adsorption function of the supplementary cooling air drying adsorbent is restored by introducing heated air from the air outlet.