JPS641403B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an apparatus for continuously producing activated carbon. Generally, activated carbon is produced using a fluidized fluidized furnace, rotary kiln, Hereschoff type multi-bed furnace, multi-stage fluidized bed furnace, etc. Raw carbon material is charged into the furnace continuously or batchwise, heated to raise the temperature, and then steam is released as appropriate. It is manufactured by injecting a large amount and activating it. Both methods have various problems regarding equipment, and it is difficult to obtain homogeneous activated carbon. The present inventors used a conventionally used activated carbon regeneration device as a production furnace, conducted basic experiments for modification, made improvements where necessary, and investigated various problems that were caused by the conventional device. We have completed an activated carbon continuous production device of the present invention that can solve the problem. The main problems that occurred in the above experiment are as follows. (1) Insufficient gas suction power in the furnace due to obstruction of ventilation in the coal seam due to steam condensation phenomenon (-50m/m water column or more). (2) Uneven addition of steam due to blockage of steam injection holes. (3) Blockage of gas suction pipe. (4) Functional failure of the discharger due to water wetting of the discharged activated carbon. (5) Blockage of gas pipes due to tar generation. (6) Increase in furnace pressure (deterioration of air permeability) due to more than 10% of the charged material having a particle size of -1m/m. (7) Poor dispersion of steam. (8) Large variation in furnace temperature. The present inventors solved these problems as follows. (1) The capacity of the in-furnace gas suction ejector was increased to about 10 times that of the above device to solve the problem of insufficient suction power. (2) Since the steam injection hole is open facing the direction in which the raw material falls, the rate at which the raw material enters is particularly high if the pressure inside the furnace becomes negative. This goal was achieved by installing a canopy above the steam pipe nozzle opening to prevent raw materials from falling and entering. (3) CO, CO ₂ , H ₂ , N ₂ generated by activation of raw materials
Since the gas suction pipes of the above are horizontal and easily clogged due to accumulation of raw materials, the purpose was achieved by slanting the gas inlet to keep it below the angle of repose and installing a shielding plate above the suction hole. (4) It was thought that the deterioration in the function of the ejector due to water wetting of the ejected activated carbon was caused by the cooling and condensation of steam in the cooling tank at the top of the ejector, so when the cooling of the cooling tank was stopped, the ejector The functional impairment disappeared. (5) A gas suction hole was installed directly above the electrode plate so that it could react with steam and CO or CO ₂ gas at the same time as tar generation. (6) The problem was solved by excluding the raw material particle size of -1m/m. (7) Regarding the decentralization of steam injection, two
A staged blowing method was adopted, in which the material was sprayed diagonally from below or above onto the descending material. (8) Fluctuations in furnace temperature are a problem that seriously affects product variations, but the present inventors inserted a plurality of electrode plates between opposing electrode plates in the furnace wall, and By narrowing the gap and energizing it, we reduced the variation in temperature. The present inventors further improved the method by extending and combining the activation zones in the height direction in order to equalize the temperature and activation, thereby making it possible to equalize the temperature and compensate for the activation. Next, an outline of the structure of a conventional energized activated carbon regeneration device will be explained with reference to FIG. The furnace body is a vertical rectangular tube with a raw material supply tank 3 at the top, and below it are a heating furnace/drying furnace 4, an activation furnace 5, a cooling tank 6, an ejector 7, and a receiving tank 8, which are assembled together. It's summery. Their inner circumferences are lined with refractory castable bricks, and their outer circumferences are wrapped with cylindrical iron plates. Electrode plates 20 of the same capacity are installed on a pair of opposing walls of the heating furnace/drying furnace 4 and the activation furnace 5, respectively. The activated carbon material in the activation furnace 5 descends, is cooled in a cooling tank 6, and then falls into a receiving tank 8 due to the rotation of the discharger 7, and is transferred to the furnace by a magnetic valve 9 provided at the bottom of the receiving tank 8 as appropriate. taken outside. This furnace body is required to be airtight so that outside air (oxygen) cannot enter. For example, after charging the raw materials into the raw material supply tank 3, the furnace cover 1 is used to prevent outside air from entering with the water seal pot 2, and the nitrogen cylinder 15 is used to remove oxygen that has already entered the furnace. _N2 gas is blown into the tank to purge oxygen. The carbonaceous material falls from the raw material supply tank 3 into the heating furnace/dryer 4, and the carbonaceous material is heated by the electric resistance heat of the electrode plate 20 to remove most of the moisture and volatile matter and improve the electrical conductivity.The carbonaceous material is then transferred to the activation furnace. In Step 5, superheated steam 11 at 450 to 500°C is blown from the nozzle 11' onto the red-hot carbonaceous material in the furnace to cause a water gas reaction. As a result,
Gases such as CO, H ₂ , CO ₂ , CH ₄ , etc. are generated from C, and the gases are led to the gas cooler 10 through the gas suction hole 19 provided on the electrode 20, where they are indirectly cooled with cold water and sent to the outside. is taken out. The heating furnace/drying furnace 4 and the activation furnace 5 have electrode plates, and the temperature rises when energized and damages the refractories, so cool air 1 is applied to the surrounding wall.
6, a cold air duct 16' is used to cool and protect the furnace wall. The cooling water 13 is used for sealing the cooling tank 6 and the water sealing pot 2, and is discharged after use. A level meter 17 for measuring the lowest level of the raw material in the hopper is placed at the bottom of the raw material supply tank 3, and an alarm is activated. The level in the tank is measured by a level meter 18. Heating furnace 4
Thermometers are placed above and below the activation furnace 5.
T ₁ and T ₂ are provided, and a manometer 12 for measuring the pressure of the heating furnace/drying furnace 4, the activation furnace 5, and the cooling tank 6 is provided.
are installed respectively. Next, we completed a system based on the findings from basic experiments.
Part 2 regarding the structure, operation, function, etc. of the device of the present invention.
This will be explained with reference to the figures and FIG. First, raw materials are pneumatically transported from outside the system and charged into the uniloader 21. The raw material falls into the raw material supply hopper 23 from the magnetic valve 22 at the lower part of the Uniloader 21, and then passes through the raw material supply tank 25 by the magnetic valve 24 at the lower part and is transferred to the drying furnace 2.
6. This device is assembled so that the heating furnace 27, the activation furnace (top) 28, the activation furnace (middle) 29, the activation furnace (bottom) 30, the cooling tank 31, the ejector 32, and the receiving tank 33 descend in this order. . A pair of electrode plates 35 are embedded in the opposing inner walls of each zone from 26 to 30, and three
It has a structure in which two electrode plates 36 of the same size are suspended at equal intervals and parallel to the opposing walls. A product discharger 32 is installed at the bottom of the cooling tank 31.
The discharged product is stored in the receiving tank 33,
The activated carbon is discharged out of the furnace by the magnetic valve 34. The uniloader 21 is provided with a bag filter 37 to collect raw material dust. A level summit indicator LS ₁ is installed in the raw material supply hopper 23. The raw material supply tank 25 is equipped with a minimum level indicator LS ₂ and an alarm transmitter LA ₁ . Temperature indicator 38 is the second
26, 27, 28, 2 as shown in the figure
There are three chambers between each electrode of 9 and 30, upper and lower, that is, (5
In addition to the number of cooling tanks (3 x 6)
1 is also provided. Steam temperature is measured at 29. Furnace pressure is 26, 27, 28, 29,
The pressure is measured from the respective furnace wall portions 30 and 31 by pressure indicators 39. The superheated steam is generated by the boiler 40, and the superheated steam is generated by the activation furnace (upper).
The steam is blown into three chambers separated by electrode plates from the intermediate part between 28 and the activation furnace (middle) 29 and the intermediate part between the activation furnace (middle) 29 and the activation furnace (lower) 30 by a steam jet nozzle. It will be done. As shown in Fig. 3, in the intermediate part between the activation furnace (top) 28 and the activation furnace (middle) 29, steam pipes 41 to 41 are all provided directly under the electrode plate of zone 28, and descend. Superheated steam is ejected diagonally to the upper left and to the upper right with respect to the carbonaceous layer, and in the middle part between the activation furnace (middle) 29 and the activation furnace (bottom) 30,
Steam pipes of 2 to 42 inches are installed between the electrode plates of 29 zones, that is, below the center of each of the three chambers of the carbonaceous layer descending from the three equally divided chambers, and are installed diagonally upward to the left and right, and diagonally downward to the left and right. A group of nozzles from which superheated steam is ejected is provided.Cooling water 43 is supplied to a gas cooler 44 and a cooling tank 31, and is cooled as waste water and then reused or discharged to the outside of the system.Cooling air 45 is It is used to cool the outer peripheral wall of the electrode plate part of the furnace.N2 gas from the nitrogen gas cylinder 46 is used to create an inert atmosphere inside the furnace, and _N2 gas is used to cool the outer peripheral wall of the electrode plate part of the furnace. ₂ gases can be injected as needed.The features and effects of the continuous activated carbon apparatus of the present invention having the above-described structure can be summarized as follows.1 Raw material supply tank 25 A drying oven 26 is provided at the bottom of the drying oven 26 and heated by electrode plates 35, 36, 36, 35.
By volatilizing part of the moisture, volatile matter, etc. in the carbonaceous material, activation conditions could be adjusted so that the carbonaceous material could be easily activated. 2 If the electrode plates are only a pair of opposing electrode plates 35 to 35 provided in the opposing walls, the gap in the furnace chamber is too large, resulting in temperature variations as the carbon material descends from top to bottom in the furnace chamber space. Although it is difficult to control the drying, heating, and activation (top, middle,
For each zone (lower), the furnace chamber space is divided into three chambers by installing two electrode plates 36 in parallel with each other at equal intervals in the lateral direction, thereby achieving a uniform temperature rise and improving product quality. This greatly contributed to quality improvement. 3. Since it is insufficient to homogenize the activation of carbonaceous material with only one activation zone,
It was found that temperature rise and activation could be made sufficiently uniform by using multiple stages in the middle and bottom. 4 Conventionally, a steam pipe was inserted into the center of the lower part of the activation zone in the activation furnace chamber, and the steam was sprayed through a nozzle hole cut into the circumferential surface of the pipe. Blowholes were easily created in localized areas of the wood furnace, and steam flow was concentrated only in areas with low resistance and easy ventilation, resulting in uneven activation. In the device of the invention, the steam pipes 41 and 42
The two nozzle tube groups are 41, 41', 4
A group of 42, 42', 41 are arranged so that steam is blown obliquely upward onto the carbonaceous layer formed by descending, and 42, 42',
A group of 42" was arranged from each steam pipe so that there were two rows of nozzle groups in which steam was blown diagonally upwards with respect to the descending direction of the carbonaceous material, and two rows of nozzle groups in which steam was blown diagonally downwards. As a result, we were able to sufficiently stir the descending carbonaceous layer and move the carbonaceous material laterally to the left and right to promote homogenization. This will be explained while comparing with the test results when used.Example Coconut chir having the quality shown in Tables 1 and 2 was used as the raw carbon material.

【table】

[Table] Table 3 shows the particle size distribution of coconut activated carbon products obtained from the same raw material using the old equipment and the equipment of the present invention, and Table 4 shows a comparison of the operation and product quality of both equipment using the same raw material. shows.

【table】

[Table] In Table 4, the product according to the present invention has a higher adsorption rate for methylene blue, iodine, etc., and a higher absorption rate for benzene. It is excellent. Also, the yield is high. To summarize the above, the apparatus of the present invention has low equipment costs, can be operated with high thermal efficiency, and can produce activated carbon of excellent quality with a high yield, and is highly effective both technically and economically. It can be said that it is a continuous energization type device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the structure of a conventional energized activated carbon regeneration device, and FIG. 2 is a schematic diagram of the structure of the device of the present invention. FIG. 3 is a diagram showing the state of superheated steam injection in the apparatus of the present invention. (Explanation of main symbols in the drawings) 3... Raw material supply tank, 4... Heating furnace/drying oven, 5... Activation furnace, 6...
...cooling tank, 7...discharge machine, 8...receiving tank, 11'...
... Superheated steam blowing nozzle, 20 ... Electrode, 25
... Raw material supply tank, 26 ... Drying furnace, 27 ... Heating furnace, 28 ... Activation furnace (top), 29 ... Activation furnace (middle), 30 ... Activation furnace (bottom), 31 ... Cooling tank ,
32... Discharge machine, 33... Receiving tank, 35... Electrode plate, 36... Electrode plate, 41-41... Steam pipe, 42-42''... Steam pipe.

Claims (1)

[Claims] 1. In a closed vertical furnace chamber, the raw carbon material is directly energized through electrodes, and superheated steam is fed into it.
In an activated carbon production apparatus that continuously performs a series of steps of drying, heating, activation, and cooling, the inner wall of the zone in which each of the above steps is performed is formed into a rectangular tube shape, and the activation zones are divided into three regions: upper, middle, and lower. electrodes are installed on the inner walls facing each of the drying, heating, and activation zones.
A plurality of electrode plates are installed in each zone at equal intervals in the lateral direction of the cross-section of the furnace space and parallel to the opposing wall, and the lower part of the upper activation zone is directly below the electrode plate, and the lower part of the middle activation zone is installed. An activated carbon production apparatus characterized in that a superheated steam inlet is provided directly below the gap between two electrode plates.