JP2004148191A - Hydrothermal treatment equipment and blockage detecting method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrothermal treatment equipment capable of previously detecting a blockage by specifying the position blocked by scale, and a blockage detecting method for the same. <P>SOLUTION: In the hydrothermal treatment equipment 1, pressure gauges PT are provided at an inlet 21a (PT1) and at an outlet 21b (PT4) of an inner pipe 21 in a heat exchanger 19, at two bent parts (PT2, PT3) of the inner pipe 21, at two joints (PT7, PT8) of an outer pipe 23, at a reactor 3 (PT5) and at a discharge pipe 41 (PT6), at a discharge pipe 55 (PT9) on the inlet side of a cooler 51 in an aftertreatment system 50, and at a vapor-liquid separator 53 (PT10). By providing the pressure gauges at the inlet side and the outlet side of the part which is likely to be blocked in the system, the start of blockage can be detected when the difference of pressure measured by the two pressure gauges gets larger and, at this point of time, it can be dealt with so as to prevent the blockage. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydrothermal treatment apparatus used for decomposition of waste, generation of energy, production of chemical substances, and the like.
[0002]
Problems to be solved by the prior art and the invention
In recent years, as one form of application of the hydrothermal reaction, a method of treating waste by oxidizing or hydrolyzing organic substances and the like in waste (liquid to be treated) has attracted attention. In this method, the waste containing organic matter is reacted with the oxidizing agent (or water) in a supercritical or subcritical state of water, and the organic matter in the waste can be almost completely decomposed in a short time.
[0003]
When oxidatively decomposing organic substances in waste by a hydrothermal oxidation reaction, waste, an oxidizing agent, and water are supplied into a reactor to react. Then, the organic matter in the waste is oxidatively decomposed (or hydrolyzed), and the carbon component is decomposed into carbon dioxide, and the nitrogen component is decomposed into nitrogen gas (ammonia or nitrate nitrogen depending on processing conditions). The resulting reaction product is recovered for energy, or after cooling and gas-liquid separation, the processing gas and the processing liquid are each discharged under reduced pressure.
[0004]
The reaction temperature of the hydrothermal oxidation reaction is determined by the amount of heat of the waste to be treated. If the calorific value of the waste is small, the reaction temperature does not rise and the desired degradability may not be obtained. On the other hand, a method of adding fuel to the waste or preheating the waste and then charging the waste into a reactor has been adopted. In particular, in the method of preheating waste, energy can be effectively used by using a heat recovery heat exchanger using reaction heat.
[0005]
In such a hydrothermal oxidation reactor, the inorganic salt may precipitate without being dissolved in water. In the hydrothermal reactor, the liquid to be treated passes through a wide temperature range from room temperature to a high temperature of 600 ° C. or higher, so that the solubility of the inorganic salt changes remarkably. In general, the solubility of salts rapidly changes near the critical temperature, and becomes lower above the critical point. Part of the salt precipitated in the hydrothermal treatment device reaches the cooling process in a suspended state, where it is dissolved in water below the critical temperature or discharged while suspended, but adheres and accumulates on the inner wall of the device. Some go. Sites where such salt deposition occurs include the inside of the reactor where the fluid temperature is high and the piping from the reactor outlet to the middle of the cooler. When a heat exchanger that preheats waste with the heat of the processing fluid is used, salt accumulation is likely to occur in a portion where the high-temperature processing fluid flows and in a portion where the high-temperature preheated waste flows.
[0006]
The salt deposited as described above grows as a scale with time in the apparatus, and eventually causes a problem that the reactor and the piping are clogged. Since the site where the salt is deposited differs depending on the temperature of the processing fluid and the composition of the salt, it is difficult to specify the position. Periodic cleaning can suppress the growth of the scale to some extent, but it has been desired to be able to evaluate the degree of growth of the scale in order to minimize the frequency of cleaning. Also, in the unlikely event of blockage, if the blockaged location cannot be identified, it is necessary to disassemble and inspect the entire device, so a means for identifying the blockaged location to some extent and reducing maintenance work was required. .
[0007]
As a method for preventing scale deposition, Japanese Patent No. 3036077 proposes a method of increasing the flow rate of a liquid to be treated to prevent settling of scale components in the same pipe. However, in this method, the pipe diameter is reduced in order to increase the flow rate, and as a result, a very long heat exchanger is required. If the flow path of the heat exchanger becomes long, it is difficult to identify the position of the blockage when the blockage occurs, and it takes time for maintenance. In addition, the reactor itself must be configured with thin piping, which limits the design of the reactor.
[0008]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydrothermal reactor capable of specifying a blockage position by a scale and detecting a blockage beforehand and a blockage detection method thereof. I do.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a hydrothermal reactor of the present invention includes a hydrothermal reactor, a supply system for supplying a liquid to be treated to the hydrothermal reactor, and cooling / reacting a reaction product of the hydrothermal reactor. A post-treatment system for decompression and discharge, comprising: a pressure gauge provided on each of an inlet side and an outlet side of a portion of the system that may be blocked by solids in the system. The blockage of the portion can be determined from the difference between the inlet pressure and the outlet pressure.
By providing pressure gauges on the entrance and exit sides of the system where a blockage is likely to occur, when the blockage starts, the difference between the pressures measured by the two pressure gauges increases, thereby notifying that the blockage has started. At this point, countermeasures can be taken to prevent blockage. Further, since the closing position and the closing state can be accurately grasped, maintenance becomes easy, and the operation rate of the apparatus is improved.
[0010]
In the present invention, if the pressure gauge is provided in the hydrothermal reactor, the inlet side of the pressure reducing mechanism in the post-processing system, and between the two, the solid component generated by the temperature change of the reaction product is generated. The obstruction state and the obstruction position due to can be grasped.
In addition, if the pressure gauge is provided on the inlet side and the outlet side of the cooling mechanism in the post-processing system, it is possible to grasp the blocking state and the blocking position due to solid components in the cooling process. This is very useful for a double tube type heat exchanger or the like which is difficult to maintain.
[0011]
In the present invention, further, a heat exchanger for exchanging heat between the liquid to be treated and the reaction product is provided, and the pressure gauge is provided on an inlet side and an outlet side of the heat exchanger. Is preferred. By providing a heat exchanger, wastes can be preheated by utilizing the heat generated by the reaction products, and the reaction efficiency increases. By providing a pressure gauge in the heat exchanger, it is possible to grasp the blockage state and blockage position due to solids generated by temperature changes of waste and reaction products in the heat exchanger. If the flow path of the heat exchanger is long, a pressure gauge may be provided in the middle of the flow path. By doing so, the closing position can be narrowed down.
[0012]
The method for detecting clogging in each part of the hydrothermal treatment apparatus of the present invention is a method for detecting clogging in each part of a hydrothermal treatment apparatus that supplies a liquid to be treated to a hydrothermal reactor and cools, depressurizes, and exhausts the generated reaction product. A pressure gauge is provided on each of an inlet side and an outlet side of a portion of the system that may be blocked by solid components, and when a difference occurs between the inlet pressure and the outlet pressure of the portion, the pressure gauge is provided. Perform part maintenance.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, description will be made with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a hydrothermal reactor according to an embodiment of the present invention.
The hydrothermal reactor 1 includes a hydrothermal reactor 3, a supply system 10 for supplying a liquid to be treated to the hydrothermal reactor 3, and cooling, decompression, and discharge of a reaction product exiting the hydrothermal reactor 3. It mainly includes a post-processing system 50. Further, the supply system 10 includes a heat exchanger 19 for exchanging heat between the liquid to be treated and the reaction product.
[0014]
The supply system 10 pressurizes and supplies the liquid to be treated, the combustion aid, water, and air to the hydrothermal reactor 3. A supply pipe 11 for waste, a combustion aid, air, and the like is connected to an inlet of the hydrothermal reactor 3. The waste is stored in a waste tank 13, and a waste supply pipe 17 equipped with a high-pressure pump 15 is connected to the waste tank 13. The waste supply pipe 17 that has exited the high-pressure pump 15 is connected to the supply pipe 11 via a heat exchanger 19.
[0015]
The heat exchanger 19 is a double tube and includes an inner tube 21 and an outer tube 23. The inner pipe 21 extends while meandering between the tip of the waste supply pipe 17 and the supply pipe 11. The outer tube 23 has a portion surrounding a straight portion (three places in this example) of the inner tube 21 and a connecting portion connecting the same portion so as to meander along the inner tube 21. The connection is a single tube. The end of the waste supply pipe 17 is connected to the inlet 21 a of the inner pipe 21, and the outlet 21 b of the pipe is connected to the supply pipe 11. A discharge pipe 41 to which a reaction product described later is sent is connected to an inlet 23 a of the outer pipe 23, and an outlet 23 b of the pipe is connected to a post-processing system 50. That is, the direction in which the waste flows in the inner tube 21 and the direction in which the reaction product flows in the outer tube 23 are opposite. The operation of the heat exchanger 19 will be described later.
The waste is pressurized by the high-pressure pump 15 and supplied to the reactor 3 through the waste supply pipe 17, the inner pipe 21 of the heat exchanger 19, and the supply pipe 11.
[0016]
An air supply pipe 27 having an air compressor 25 is connected to the supply pipe 11. The air as the oxidizing agent is taken into the air compressor 25 and compressed, and is supplied from the air supply pipe 27 to the reaction vessel 3 through the supply pipe 11.
[0017]
The combustion aid is stored in a tank 29, and the tank 29 and the supply pipe 11 are connected by a combustion aid supply pipe 33 provided with a high-pressure pump 31. The auxiliary agent is pressurized by the high-pressure pump 31 and supplied to the reactor 3 through the auxiliary agent supply pipe 33 and the supply pipe 11. For example, petroleum such as alcohol and kerosene can be used as the auxiliary agent.
Water is stored in a tank 35, and the tank 35 and the supply pipe 11 are connected by a water supply pipe 39 provided with a high-pressure pump 37. Water is pressurized by a high-pressure pump 37 and supplied to the reactor through a water supply pipe 39 and a supply pipe 11.
The high-pressure pumps 15, 31, and 37 are pumps capable of increasing pressure at a high pressure, such as reciprocating pumps, and having capacity controllability, and are capable of adjusting supply amounts of waste and fuel into the reactor 3. .
[0018]
The hydrothermal reactor 3 is made of a material having corrosion resistance, heat resistance, and pressure resistance. The reactor is composed of an upper structure 3a in which a columnar space is formed and a lower structure 3b in which a funnel-shaped space is formed. An inlet for the liquid to be treated is opened above the upper structure 3a, and a supply pipe 11 is connected to the inlet. At the lower end of the funnel-shaped space of the lower structure 3b, a through-hole serving as an outlet for a reaction product or the like is formed. The inlet and the outlet are arranged on the same axis as the central axis of the cylindrical space and the funnel space.
[0019]
The outlet of the hydrothermal reactor 3 is connected to a discharge pipe 41. As described above, the end of the discharge pipe 41 extends to the heat exchanger 19 in the supply system 10 and is connected to the inlet 23a of the double pipe outer pipe 23. A discharge pipe 55 coming out of the outlet 23b of the outer pipe 23 extends to the post-processing system 50.
The post-processing system 50 includes a cooler 51 and a gas-liquid separator 53. The reaction products and the like that have exited the heat exchanger 19 pass through the discharge pipe 55, are cooled to almost normal temperature by the cooler 51, and are then converted into the processing gas (N ₂ , CO _2, etc.) and the processing liquid by the gas-liquid separator 53. Separated.
[0021]
A drain pipe 59 having a pressure reducing valve 57 is connected to the bottom of the gas-liquid separator 53. The waste liquid from which gas-liquid separation has been performed is reduced to a pressure close to the atmospheric pressure by a pressure reducing valve 57 and sent to a processing liquid tank (not shown). An exhaust pipe 63 having a pressure reducing valve 61 is connected to an upper end of the gas-liquid separator 53. The gas-liquid separated exhaust gas is reduced in pressure to a pressure close to the atmospheric pressure by the pressure reducing valve 61 and discharged.
[0022]
The hydrothermal reactor 1 is provided with a plurality (ten in this example) of pressure gauges PT1 to PT10.
In the heat exchanger 19, the pressure gauge PT includes an inlet 21 a (PT 1) and an outlet 21 b (PT 4) of the inner tube 21, two curved portions (PT 2, PT 3) of the inner tube 21, and two outer tubes 23. It is provided at two connection parts (PT7, PT8). Further, it is provided in the reactor 3 (PT5) and the discharge pipe 41 (PT6). Further, in the post-processing system 50, a discharge pipe 55 (PT9) on the inlet side of the cooler 51 and a gas-liquid separator 53 (PT10) are provided.
[0023]
Next, the operation of the hydrothermal reactor 1 will be described.
The hydrothermal reactor 3 of the hydrothermal reactor is preheated to a predetermined temperature, and waste as a reactant is supplied to the reactor 3 from the waste tank 13 through the inner tube of the heat exchanger 19. At this time, compressed air, which is an oxidizing agent, is also supplied. In addition, if necessary, an auxiliary agent or water is supplied for heat quantity adjustment. These substances react in the hydrothermal reactor 3 to produce a reaction product. The reaction product flows to the outlet along the funnel-shaped inner wall of the funnel-shaped space of the hydrothermal reactor 3, and is sent to the outer pipe 23 of the heat exchanger 19 through the discharge pipe 41. Here, the high-temperature reaction product flows in the outer pipe 23 in a direction opposite to the direction of the flow of the waste flowing in the inner pipe 21. Then, while passing through the heat exchanger 19, heat exchange is performed with the waste, and the waste is preheated. At the same time, the reaction product is deprived of heat and the temperature drops.
[0024]
The reaction product whose temperature has dropped flows through the drain pipe 55 and is cooled by the cooler 51. The reaction product after cooling is separated by a gas-liquid separator 53, and the separated processing liquid passes through a drain pipe 59 and is collected by a pressure reducing valve 57 in a pressure-reducing post-processing liquid tank. On the other hand, the processing gas is discharged from the exhaust pipe 63 after the pressure is reduced by the pressure reducing valve 61.
[0025]
In such a hydrothermal reaction process, the detection values of the pressure gauges PT1 to PT10 installed at a plurality of locations are read at appropriate timing to grasp the state of blockage of the piping in the system.
For example, by the pressures detected by the adjacent pressure gauges PT1 and PT2, the accumulation of scale in the first straight portion of the inner pipe 21 due to solids and salts in the waste sent from the waste tank 13 is prevented. I can understand. Similarly, due to the pressure detected by the adjacent pressure gauges PT2 and PT3, the scale is deposited and adjoined from the upstream curved portion of the inner pipe 21 to the downstream bay local portion through the second straight portion. Based on the pressures detected by the pressure gauges PT3 and PT4, the accumulation of scale on the third straight portion of the inner tube 21 can be grasped. In the heat exchanger 19, as described above, the salts in the waste become high in temperature and easily precipitate. In addition, the inner tube 21 of the heat exchanger 19 has a curved shape, and solids and the like in the waste easily accumulate. For this reason, in this example, the inner pipe 21 is divided into three locations, and the scale accumulation at each location can be individually grasped.
[0026]
On the other hand, in the discharge pipes 41 and 55, the inner pipe of the cooler 51, and the outer pipe 23 of the heat exchanger 19, insoluble salts in the processing liquid may accumulate in the pipes. Therefore, the deposition of the scale can be grasped by the pressures detected by the pressure gauges PT6, PT7, PT8, PT9, P10 provided in such places.
[0027]
Further, the scale accumulation in the reactor and at the lower part of the reactor can be grasped by the pressure gauge PT5 provided in the reactor 3 and the pressure gauge PT6 provided in the reactor outlet pipe 41.
[0028]
Then, a difference between the pressures detected by the two adjacent pressure gauges is obtained, and if there is a difference, it is understood that the scale has started to be deposited on a portion between these two pressure gauges. Then, when the difference becomes a certain level or more, maintenance such as cleaning of the apparatus is performed.
Note that the pressure difference may be obtained by reading the indicated value of an analog pressure gauge and calculating the difference, but it is hardly sufficient in terms of accuracy. Preferably, pressure is output as an electric signal from the pressure detector, and the pressure difference can be detected with high accuracy by calculating the pressure. In addition, the use of a differential pressure gauge also enables highly accurate detection of a pressure difference.
[0029]
【The invention's effect】
As apparent from the above description, according to the present invention, in the hydrothermal reaction system, pressure gauges are provided on the inlet side and the outlet side of a portion where blockage by solids is likely to occur, and the pressure difference between the two portions is reduced. By grasping it, it is possible to identify the occurrence status and location of the blockage in the system. Then, by performing maintenance of the specified portion, blockage can be prevented beforehand, and the operability of the device can be increased.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a hydrothermal reactor according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hydrothermal reactor 3 Hydrothermal reactor 10 Supply system 11 Supply pipe 19 Heat exchanger 13 Waste tank 15 High pressure pump 17 Waste supply pipe 21 Inner pipe 23 Outer pipe 25 Air compressor 27 Air supply pipe 29 Tank 31 High pressure pump 33 Combustion agent supply pipe 35 Tank 37 High pressure pump 39 Water supply pipe 41 Drain pipe 50 Post-processing system 51 Cooler 53 Gas-liquid separator 55 Drain pipe 57 Pressure reducing valve 59 Drain pipe 61 Pressure reducing valve 63 Exhaust pipe PT1 to PT10 Pressure gauge

Claims (5)

A hydrothermal reactor,
A supply system for supplying the liquid to be treated to the hydrothermal reactor,
A post-treatment system for cooling, depressurizing, and discharging the reaction product of the hydrothermal reactor;
A hydrothermal treatment device comprising:
A pressure gauge is provided on each of the entrance side and the exit side of the portion that may be blocked by solids in the system,
A hydrothermal treatment apparatus characterized in that the blockage of the part can be determined from the difference between the inlet pressure and the outlet pressure of the part. 2. The hydrothermal treatment apparatus according to claim 1, wherein the pressure gauge is provided on an inlet side of the hydrothermal reactor, a pressure reducing mechanism in the post-processing system, and between the both. 3. The hydrothermal treatment apparatus according to claim 1, wherein the pressure gauge is provided on an inlet side and an outlet side of a cooling mechanism in the post-processing system. Further, a heat exchanger for performing heat exchange between the liquid to be treated and the reaction product,
The hydrothermal treatment apparatus according to claim 1, wherein the pressure gauge is provided on an inlet side and an outlet side of the heat exchanger. A method for detecting clogging in each part of a hydrothermal treatment apparatus that supplies a liquid to be treated to a hydrothermal reactor and cools, decompresses, and exhausts the generated reaction product,
A pressure gauge is provided on each of the inlet side and the outlet side of a portion that may be blocked by solids in the system,
When there is a difference between the inlet pressure and the outlet pressure of the portion, maintenance of the portion is performed.

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