JPS6324407B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an in-pipe granulation method for coal/water slurry. Structure of conventional methods and their problems When transporting large amounts of coal, slurry transport is said to be economically advantageous compared to conventional transport methods (trucks, railways, conveyors). However, if the coal/water slurry is loaded onto a ship as is, it will not have good dewatering properties, causing problems such as the loading time. Therefore, it has been considered to install a coal/water slurry granulation device at the shipping port to increase the average diameter of coal particles. This is because the larger the coal particles, the easier it is to dehydrate. Figure 1 shows the overall equipment of a conventional coal/water slurry transportation pipeline. In the figure, 1 is a slurry adjustment device installed at the base of the mountain, 2 is a pump installed in the middle of the pipeline, and 3 is a stirring tank for granulating the coal/water slurry pumped from pump 2. A granulating emulsion 4 obtained by emulsifying water, heavy oil, and a surfactant is supplied to the inlet of the stirring tank 3 together with the coal/water slurry. Reference numeral 5 denotes a sieve bend provided at the loading dock, which functions to separate the granulated coal/water slurry into water 6 and granulated coal 7. In addition, 8 indicates a heating and warming device. Conventionally, granulation of coal/water slurry with such a configuration has been considered, but this method has had the problem of requiring large stirring power. There is also equipment that uses a centrifugal pump instead of the stirring tank 3, but in this case there are problems such as rapid wear of the pump impeller. Therefore, in any case, transportation costs were inevitably high. OBJECTS OF THE INVENTION It is an object of the present invention to provide an in-pipe granulation method for coal/water slurry that solves these problems. Structure of the Invention In order to achieve the above object, the in-pipe granulation method for coal/water slurry of the present invention includes
A granulating emulsion made by emulsifying water, heavy oil, and a surfactant is added, and the emulsion is flowed through a pipeline with a length that maintains a residence time of at least 30 minutes from the point of addition to the destination. It has a structure in which it is granulated, which can significantly reduce transportation costs. Embodiment and Operation An embodiment of the present invention will be described in detail below with reference to the drawings. First, FIG. 2 shows the entire equipment of a coal/water slurry transport pipeline used in the method of the present invention. In the figure, 10 is a slurry adjustment device installed at the base of the pile, 11 is a pump installed in the middle of the pipeline, and 12 is a slurry concentration adjustment device installed upstream of the last pump 11. It functions to adjust the slurry concentration of coal/water slurry sent through the pipeline to a slurry concentration of 10 to 45 wt%. 13 is a granulating emulsion made by emulsifying water, heavy oil (for example, Middle East C heavy oil), and a surfactant, and is added into the pipeline at a point several kilometers or more away from the sieve bend 14 installed at the shipping port. It is said that the configuration is as follows. In addition, in this figure, the distance from the slurry adjustment device 10 to the sheave bend 14 is several hundred kilometers.
A pipeline is assumed, and the length of the pipeline from the addition point of the granulating emulsion 13 to the sieve bend 14 is set to maintain a residence time of at least 30 minutes or more. Reference numeral 15 denotes a heating and warming device which is installed as necessary at the addition position of the emulsion 13 for granulation, and uses a heat exchanger, for example, to maintain the temperature of the coal/water slurry at 15° C. or higher. Therefore, if the temperature of the coal/water slurry is within 15°C to 40°C, the heating/warming device 15 may not be provided. FIG. 3 is a modification of FIG. 2, showing an enlarged view of the area from the addition point of the granulating emulsion 13 to the sieve bend 14. In this case as well, the length of the pipeline from the addition point of the granulating emulsion 13 to the sieve bend 14 is set to a length that will maintain the residence time of at least 30 minutes or more. As is clear from the figure, the pipeline has a bent route 16 within this range of several tens of kilometers, and elbows or bends 17 are interposed at the many bent portions. Reference numeral 18 indicates an orifice interposed in the middle of the bent path 16, and reference numeral 9 indicates a pipeline mixer. With such a configuration, first, the coal/water slurry is adjusted using the slurry adjusting device 10 at the base of the pile. At this time, the slurry concentration is maintained at 45 to 55 wt%. Next, the slurry concentration is adjusted to 10 to 45 wt% in the middle of the pipeline using the slurry concentration adjusting device 12.
Then, the emulsion 13 for granulation is added to the coal/water slurry several kilometers or more before the shipping port. If the temperature of the coal/water slurry is less than 15°C at this addition point, the temperature is maintained at 15°C or higher using a heating/warming device 15.
The coal/water slurry sent in this manner then flows through the bent path 16 shown in FIG. 3. The coal/water slurry is then exposed to strong turbulence at the orifice 18, elbow or bend 17, and the emulsion 13 in the slurry is dispersed to form a thin oil film on the surface of the coal particles. Then, when the collision between the coal particles is promoted, the coal particles stick together and granulation begins. That is, the coal/water slurry can be granulated without using any stirring tank or the like. Particularly in long-distance slurry flow pipes, granulation nuclei generated at orifices, elbows, or bends that begin granulation grow and grow into particles of an appropriate particle size. The granulated coal slurry that has been granulated is discharged from the bent path 16 to the sieve bend 14 and separated into water 19 and granulated coal 20. Note that the pipeline mixer 9 and orifice 18 are located at bend 1.
7, and may be omitted. FIG. 4 is a longitudinal sectional view showing an example of a slurry transportation route. As is clear from the diagram, there is usually considerable ups and downs from Yamamoto I to loading point Ro. Therefore, it can be seen that from the addition point of the granulating emulsion 13 to the sieve bend 14, the beam is bent not only in a plane but also in the vertical direction. Therefore, since a large number of elbows or bends are interposed, more efficient granulation can be achieved in this embodiment. FIG. 5 shows a third embodiment. That is, the bent route 16 shown in FIG. 3 is further bent to create a meandering route 23 to increase the chances of slurry collision, shorten the granulation time, and make the pipe length shorter than in the case of only horizontal pipes. This is what I did. Other configurations such as the length of the pipeline are the same as in FIGS. 2 and 3, so the same numbers are given. In addition,
According to such a configuration, the elbow or bend 17 is relatively easily worn, so it is preferable to use the elbow or bend 17 by reversing the mounting direction as appropriate. In addition, to transport granulated coal by ship to a remote location, the dehydrated granulated coal can be shipped as is, or the granulated coal slurry that has been granulated in a pipe can be shipped as is and dehydrated on board. Also good. FIG. 6 shows an experimental example. In the figure, 24 is a storage tank for coal/water slurry, 25 is a reciprocating piston pump for pumping the coal/water slurry supplied from this storage tank 24, and 26 is a meandering pipe connected to this reciprocating piston pump 25. A 180° elbow 27 is used at the bend in the route. 28 is an auxiliary tank that temporarily stores the coal/water slurry that has passed through the meandering path 26. The coal/water slurry stored in this auxiliary tank 28 is transferred to the storage tank 24 and the reciprocating piston pump 25.
The configuration is such that it returns to the route connecting the two. 29 is an emulsion storage tank for supplying emulsion for granulation into the path before the reciprocating piston pump 25, and has a built-in heater 30. Reference numeral 31 denotes a heating and insulating device installed in the meandering path 26 in front of the auxiliary tank 28, and serves to maintain the temperature of the coal/water slurry at 15° C. or higher. Note that 32 represents a pump, and 33 and 34 represent valves. With this configuration, first, the slurry concentration is about 30 wt% and the slurry temperature is 30 to 40°C from the storage tank 24.
reciprocating piston pump 25
The valve 33 was opened and the water was supplied. Then, after feeding the coal/water slurry with a total weight of 560 kg into the meandering path 26 using the reciprocating piston pump 25, the valve 3
3 was closed to form a loop line consisting of the reciprocating piston pump 25, the meandering path 26 and the auxiliary tank 28. Then, the flow velocity of the slurry in the pipe is
The loop line was circulated at a speed of 2.0 m/s to 3.0 m/s. Next, the valve 34 was opened and the emulsion for granulation was added into the passage from the emulsion storage tank 29. At this time, the emulsion for granulation is
An emulsion of water, 200 ppm of surfactant, and oil (Middle East heavy oil) heated and stirred at 70°C was used. Also, the amount added is 1.5 for coal/water slurry.
I weighed 100kg during the three rounds. Figure 7 and the table below show the results. As a result of this test, if the temperature of the coal/water slurry during granulation is less than 15℃, granulation will take longer.

[Table] A long granulation pipe and a large number of elbows 27 are required, and if the temperature is to be raised to 40°C or higher, even more powerful heating equipment is required, making it impractical. Therefore, 15 to 40°C is considered to be the appropriate temperature.
In addition, if the slurry concentration during granulation is less than 10wt%, the amount of granulation per unit time is small, making it uneconomical.On the other hand, if it exceeds 45wt%, granulation is difficult. Ta. As a result of adding the emulsion for granulation, granulation started after about 20 minutes, and after about 60 minutes, the particle size was 32 mesh or more.
We were able to obtain granulated coal that accounted for 96% (see Figure 7). Effects of the Invention As described above, according to the method of the present invention, the power required for granulation can be reduced compared to conventional methods, and transportation costs can be significantly reduced. Furthermore, it is possible to perform granulation within a tube in a narrow area. Furthermore, since there is no need to use a stirring tank, safety can be improved and the degree of scattering of coal dust can be reduced. Furthermore, more efficient granulation can be achieved by using a pipeline with multiple elbows or bends.

[Brief explanation of drawings]

Fig. 1 is a process diagram of a conventional coal/water slurry transport pipeline, Figs. 2 to 7 are for explaining the method of the present invention, and Fig. 2 is a flowchart for transporting coal/water slurry according to the method of the present invention. Figure 3 is a process diagram showing a modification of Figure 2, Figure 4 is a longitudinal cross-sectional view of the slurry transport route, and Figure 5 is a flowchart of the coal/water slurry transport pipeline in the third embodiment. FIG. 6 is a process diagram of a coal/water slurry transport pipeline in an experimental example, and FIG. 7 is a diagram showing the relationship between granulation time and granulation state. 13... Emulsion for granulation, 17, 27... Elbow or bend, 23, 26... Meandering path.

Claims (1)

[Claims] 1 A granulation emulsion made by emulsifying water, heavy oil, and a surfactant is added to the coal/water slurry, and the length is such that the residence time is maintained for at least 30 minutes from the point of addition to the destination. An in-pipe granulation method for coal/water slurry, which is characterized by granulating it by flowing it through a pipeline.