JPS63105195A - Multistage explosion grinding of fibrous material - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Industrial Application Field] The present invention relates to an improvement in a blasting method for crushing and fiberizing fibrous materials such as wood chips.

1. Prior Art In recent years, fibrous materials such as wood have been turned into animal feed, saccharified,
There is active research into the use of woody biomass, such as carbon dioxide, and the acquisition of alternative energy to oil and coal through alcohol fermentation. Explosive crushing is performed as one of the pre-treatments for such use.

Explosive crushing involves steaming wood chips and other materials in high-temperature, high-pressure steam and then rapidly releasing the pressure, resulting in explosive volumetric expansion due to vaporization of condensed water and mechanical destruction caused by high-speed jets from a nozzle. This is the process of forming wood into cylinders and turning it into fibers.

The problem faced when attempting to carry out blasting continuously is how to continuously supply a discontinuous solid raw material such as wood to a container at high temperature and high pressure.

As a solution to this problem, for example,
Publication No. 385 discloses a technology that uses a screw compactor as a feeder to continuously supply compacted plug molded products such as wood chips to high pressure while crushing them using an on-off valve equipped with a cutting blade. has been done.

While this technology is a major advance in making it possible to continuously feed raw materials, screw compactors require excessive power to maintain a stable seal with the high-pressure system, and are difficult to operate. lack of stability above, and difficulty in scaling up after mechanical groove construction;
remains a problem.

[Problems to be Solved] An object of the present invention is to solve the above-mentioned problems without using power for sealing between the fibrous material supply system and the high-pressure treatment system, and without using complicated mechanical methods. It is an object of the present invention to provide a multi-stage blasting method for fibrous materials that does not require structural equipment, is easy to scale up, has high operational stability, and can be operated semi-continuously.

Structure of the Invention [Means for Solving the Problems] To explain with reference to the drawings, the multi-stage blasting method for fibrous materials of the present invention, as shown in FIG. In this method, a plurality of pressure-resistant containers R1, R2, R3,
・Using a device in which Rn are arranged in series and each container is connected with a valve, the fibrous material F is supplied to the first stage pressure container R1 and subjected to a predetermined high temperature and high pressure condition. After steaming, the pressure is sequentially transferred to the pressure vessels R2, R3, . . .
It consists of taking out the pressure vessel R0 of the final stage to a vessel under atmospheric pressure, and is characterized by performing blasting during the above transition. In FIG. 1, reference numeral 1 denotes a water sprinkling hopper for storing the fibrous material F, and is equipped with a water sprinkling nozzle 11 for imparting appropriate moisture to the material F. At the bottom of the watering hopper 1, two feeders 2A and 2B for transferring the material F are installed, and each feeder is connected to two pre-storage hoppers 3A.

3B through electromagnetic on-off valves EV. The two pre-storage hoppers 3A and 3B are
Both are pressure vessels themselves, and both communicate with the first stage pressure vessel R1.
This allows material F to be supplied alternately to each other.

The first-stage pressure vessel R1 is a vessel for steaming the fibrous material at high temperature and high pressure, and high-pressure steam can be forced into it through a pipeline. Pressure vessel R1
Underneath the pressure vessels R2, 2nd, 3rd... nth stage,
R3...Rn are connected and arranged in series, and each container is partitioned off by an electromagnetic opening/closing valve EV as described above. By opening and closing these valves, it is possible to arbitrarily establish electrical continuity between the respective pressure vessels.

The final stage pressure vessel Rn is connected to two final hoppers 6A and 6B each equipped with an agitation unit 61, and alternately receives the processed material P released from the pressure vessel R1 and discharges it to the separation tank 7. It is possible to do so.

In the figure, the electromagnetic on-off valves EV are automatically closed one after another according to a predetermined time schedule by a known sequence control system. Each hopper and pressure vessel has
Needless to say, the necessary pressure gauges, thermometers, storage level gauges, level display controllers, etc. are provided.

Figures 2 to 4 show the construction of various pressure vessels.

The pressure vessel shown in FIG. 2 has a rural-like agitation eye 8A installed laterally at the bottom, and discharges the processed material from the lower nozzle 9 while breaking the bridge of the processed material by internal stirring. This is suitable for processing fibrous materials with a relatively low degree of bridging. The pressure vessel shown in FIG. 3 is equipped with a screw conveyor 8B at the bottom and is therefore suitable for materials that are difficult to discharge. Twin screws are used if necessary.

The pressure vessel shown in Fig. 4 has a ribbon-shaped screw 8C inside the vessel.
is installed vertically, and the processed material is discharged by pushing down while internally agitating it.

This device is suitable for materials that are extremely difficult to discharge.

The pressure vessels R1, R2, . . . , Rn shown in FIG. 1 are examples in which the type shown in FIG. 3 is used.

Next, in FIG. 1, an explanation will be given of an explosion method when the pressure vessels are arranged in n=4, that is, in four stages. In the following description, the pressure vessel R1 will be abbreviated as "R1" and the electromagnetic on-off valve EV will be abbreviated as valve rEVJ.

After a predetermined amount of the fibrous material F stored in the watering hopper 1 is transferred to the pre-storage hopper 3A by the feeder 2A, the valve EV at the bottom of the hopper is opened and the fibrous material F is supplied to the first stage container R1.

After sealing the container R1 and pressurizing high-pressure saturated steam through the pipeline 4 and steaming it for a certain period of time, the valve EV at the bottom of the container R1 is turned on, and the contents are transferred to the second stage container R by pressure difference.
2 to squirt.

When all the contents in container R1 have been introduced into container R2, the valve EV of container R1 is closed, and the third stage container R3 is opened.
to squirt. In this way, the contents of each container are sequentially ejected, and finally the contents of container R4 are ejected into the final hopper 6A.

When the processing contents reach the final hopper 6A, they are placed in a high temperature and low pressure (for example, atmospheric pressure) state,
The valve EV at the top of the hopper 6A is closed, and the hopper 6A is discharged into the separation tank 7 under atmospheric pressure.

With the above steps, the processing of the first batch is completed, and in parallel with this, processing of the second batch is performed.

That is, when the contents of the first batch are transferred from container R2 to R3, another pre-storage hopper 3
A second batch of fibrous material, previously supplied in B, is introduced into container R1.

At this time, the container R1 is in a sealed state, and residual pressure after the first batch processing remains inside. Therefore, after closing the valve EV at the top of the pre-storage hopper 3B to isolate it from the feeder 2B, open the valve ■ of the conduction pipe connecting the top of the hopper 3B and the container R1 to equalize the pressure between the container R1 and the hopper 3B. After that, when the valve EV at the bottom of the hopper 3B is turned on, the fibrous material F is pushed into the container R1 by its own weight.
be introduced within. Next, the valve V around the container R1
and EV, and after sealing both, container R
In the same manner as above, high-pressure saturated steam is injected into 1. on the other hand,
The residual pressure in the pre-storage hopper 3B is released to the separation tank 7 through the final hopper 6B.

The contents of the first batch are ejected from the container R4 to the final hopper 6A, and at the same time the contents of the second batch are ejected from the container R1 to R2. Hereafter, the same operation as the first batch is repeated.

The same applies to the third and subsequent batches, and semi-continuous operation is continued by repeating the above steps.

The conditions for processing the fibrous material in the first stage container R1 vary depending on the raw materials such as wood chips and straw, but the pressure is usually in the range of 20 to 30 KFI/ci・G, and the temperature is the steam temperature corresponding to this pressure. However, the pressure in the final stage container R0 may be determined so as to reach the required pressure.

[Function] In the method of the present invention, the fibrous material steamed under high temperature and high pressure is sequentially transferred from the high pressure system to the low pressure system by opening and closing the valves between the pressure vessels partitioned into each system. It erupts adiabatically, and the pressure drops step by step but rapidly. While repeating such gradual and sudden changes in pressure, evaporation from the surface of the material to be treated and rapid volumetric expansion of water from inside the material (bunchout) occur, causing physical and chemical changes in the material. , its crushing and fiberization are achieved.

On the other hand, the initial amount of heat given to the object to be processed undergoes a sequential adiabatic change, which is different from the conventional one-step pressure release method from high pressure to atmospheric pressure, so there is little heat loss per se, and some of it remains. Since it can be used as pressure, it is effectively consumed.
At the final stage of the multi-stage operation, the pressure is low, and it is easy to remove the material to be processed from the system.

The most significant advantage of the method of the present invention is that a simple gate valve (electromagnetic on-off valve) is required between the supply system of the processed material and the high-pressure treatment system for high-pressure sealing, which eliminates the need for the conventional method. This is achieved by not requiring high power. This eliminates the need for complicated mechanical drawing equipment and facilitates scale-up of the equipment.

[Example] In Fig. 1, using four stages of containers R1 to R4, wood chips at room temperature (moisture content 20% > 10 kg) were cut into 30/cut-G in the first stage container R1, 235 After steaming at ℃ for 5 minutes, the pressure was sequentially lowered from R2 to R4 and exploded. Each container R1 to R4, press 1 to range hopper 3△, 3B, and final hopper 6A, 6B.
used, each having a capacity of 50 g.

Examples of operations in each blasting step and each container R at that time
The pressures and temperatures of 1 to R4 and hoppers 3A, 3B, 6A, and 6B are shown in the table.

Step 1 is 3/car G to 30 in the previous step,
The pressure and temperature conditions in each container are shown at the stage when the material that has been steamed at 235° C. for 5 minutes is exploded from container R1 to container R2. In this step, on the other hand, the container R
The operation of the previous batch, ie, the discharging from 4 to the final hopper 6B, is also being carried out in parallel. Note that the container R3 is partitioned at this time with a residual pressure of 7.5 KFl/cm.G.

Step 2 is a stage in which blasting from container R2 to container R3 has been performed, and in parallel, the next batch operation of supplying material from prestorage hopper 3B to container R1 is also performed. There is.

Step 3 is the stage of blasting from container R3 to container R4, while for the next batch, 30'l/cvr.G steam is supplied to the material introduced into container R1 and steaming is carried out. It is.

Step 4 is a repeat of step 1.

As seen in this table, after the blasting of container R1 to container R2, container R1 is 22°5 K'l/
It has a residual pressure of ci·G, which effectively contributes to reducing the steam requirement for the next steaming process. In the case of single-stage blasting, the pressure inside the container R1 is atmospheric pressure, so approximately 2 J of 30/crj-G steam is required to steam 10 kg of water-containing wood chips at room temperature. However, if there is a residual pressure of 22.5 KFJ/aM-G in the container R1 as in the present invention, it will cause the water-containing chips at room temperature to
It contributes to raising the level to C level, so 3/cr to 30
Approximately 1.5 kg of i/G steam is sufficient, resulting in approximately 25% steam savings.

In addition to the above embodiments, the method of the present invention allows for a wide variety of combinations, such as setting the pressure and temperature of each container to the same conditions as the previous processing conditions, or setting them completely different. be.

In this case, the conditions under which the residual pressure can be used as effectively as possible may be determined experimentally from the properties of the fibrous material to be treated and the number of stages of the required container capacity.

Effects of the Invention According to the multi-stage blasting method of the present invention, the effect of blasting can be reduced by reducing heat loss. That is, the fibrous material heated to high temperature and high pressure in the first-stage container is successively subjected to pressure changes in an adiabatic manner, and is exploded each time. Not only does the pressure change itself cause little heat loss, but the residual pressure can be used for the next treatment, further saving energy. Since the material is supplied at normal pressure, no power is required to seal with the high pressure system, and the container used for the blasting process can be of a simple pressure-resistant structure, making it easy to scale up.

By using multistage containers, it is possible to arbitrarily combine operating conditions such as temperature and pressure to set optimal blasting conditions according to the properties of the fibrous material.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a multi-stage blasting apparatus for carrying out the method of the present invention. FIGS. 2, 3, and 4 are explanatory diagrams showing the structure of various aspects of the pressure vessel used in the apparatus shown in FIG. 1. 1... Watering hopper 2A, 2B... Feeder 3A, 3B... Pre-storage tank 4.5... Pipeline 6A, 6B... Final hopper 7... Separation tower RnR2, R3... Rrl...pressure vessel.

Claims (1)

[Claims] In a method in which a fibrous material is steamed in high-temperature, high-pressure steam and then exploded by rapidly releasing the pressure, a plurality of pressure-resistant containers R_1, R_2, R_3...R
Using a device consisting of __n arranged in series and connecting each container with a valve, the fibrous material is supplied to the first stage pressure vessel and steamed under predetermined high temperature and high pressure conditions. The pressure is sequentially transferred to the pressure vessels R_2, R_3...R_n in the second and subsequent stages by differential pressure, and the pressure is lowered step by step, and the pressure is taken out from the final stage pressure vessel R_n to a vessel under atmospheric pressure. , a multi-stage blasting method for fibrous materials, characterized in that blasting is carried out during the above transition.