JPH11267401A - Treatment and treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove metal and nonmetal materials stuck on the surface of a material to be treated extremely well without using a special cleaning agent, combustion flame or the like. SOLUTION: In this method, after a material to be treated 1 is fed into a closed space 2 and the closed space 2 is evacuated, a non-oxidizing gas is fed and also primary heating is performed. Then, after the closed space is evacuated, secondary heating is further performed to evaporate liquid and solid materials stuck on the material to be treated 1 and the evaporated materials are housed in a condenser to condense them. Then, the non-oxidizing gas is fed again to cool the material to be treated 1. The oxidizing gas warmed by this cooling treatment is introduced into a preheating furnace 31 to preheat the untreated material to be treated 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method suitable for removing liquids such as water, oil, galvanized and solids adhered to the surface of an article.

[0002]

2. Description of the Related Art Conventionally, as a method for removing galvanization or the like on the surface of an automobile, for example, pickling, shot processing, or oxidative removal in air has been known.

[0003] Of these, pickling is the most common, but it has problems not only in that the washing solution may cause pollution, but also in terms of running costs and ensuring the training of workers. The shot processing method also has problems such as high running cost and difficulty in processing shot particles to which zinc is attached.

On the other hand, in the oxidative heat removal method, an oxide or the like is formed on the object to be treated, and the dezincing performance is poor. Therefore, when the iron plate is melted for reuse, noro (insoluble material) such as iron oxide and zinc oxide and zinc enter the furnace wall of the melting furnace, and as a result, the life of the furnace itself is shortened. There is.

[0005]

As described above, the conventional cleaning method has many problems. Therefore, the present invention
It is an object to provide a method for cleaning a solid surface without such a problem.

[0006]

According to the present invention, an article to be processed is charged into an enclosed space, and after the interior of the enclosed space is depressurized, a non-oxidizing gas is supplied and primary heating is performed. Further, secondary heating is performed to evaporate liquid and solid deposits adhering to the article to be treated, and the evaporant is stored in a condenser to be condensed. Is cooled, and the non-oxidizing gas warmed by the cooling treatment is introduced into a preheating furnace to preheat an untreated and untreated workpiece.

By the way, the enormous amount of waste in modern society is increasing daily, and it is urgently necessary to establish an effective treatment technology.

Although various useful substances are contained in waste, they are not separated from waste due to difficulty in separation.
Most waste is disposed of by landfill or incineration. Useful substances in waste should be separated and
It is required to collect and reuse.

[0009] On the other hand, harmful substances are contained in wastes, and such harmful substances not only cause environmental destruction but also one of the major causes that make it difficult to recycle waste. It is. If harmful substances in waste can be effectively removed, the waste can be actively reused as a treasure trove of resources, and the impact on the environment and living things can be minimized.

As described above, a technology for effectively treating waste must be established in order to solve serious problems surrounding modern society such as environmental pollution by harmful substances, depletion of resources, and lack of energy sources. Must.

However, in recent years, the form of waste has become complicated and diverse, and there are many complex wastes in which a plurality of different materials are integrated, and there are also wastes containing harmful substances. In order to reuse such complex waste as a resource, it is necessary to selectively separate and recover useful and harmful substances from the waste in which multiple different materials are integrated. Such processing technology has not been established yet.

The present invention has been made to solve such a problem. That is, the present invention relates to metals, organic substances,
It is an object of the present invention to provide a processing apparatus and a processing method capable of effectively and economically processing an object including water and the like.

In order to solve such a problem, the present invention employs a configuration as described below.

The treatment method of the present invention comprises a first component which is liquid at ordinary temperature, a second component which is solid at ordinary temperature, and a third component which is solid at ordinary temperature and has a higher boiling point than the second component. In the processing method for processing the object to be treated including the components, the object to be treated is introduced into an airtight container, the object to be treated is heated in a non-oxidizing atmosphere, and the inside of the airtight container is depressurized, and the first The first component or the second component is heated by heating to a temperature equal to or higher than the boiling point of the component or the second component.

Examples of the first component include organic substances such as water and oil, and mercury. The second component and the third component are not limited to organic substances and inorganic substances, and examples thereof include organic substances such as dioxin, PCB and coplanar PCB, and metals such as lead, cadmium and zinc. Here, polychlorinated dibenzoparadioxin (Pol
ychlorinated dibenzo-p-di
oxins: PCCDs), polychlorinated dibenzofuran (Polychlorinated dibenzof)
urans: PCDFs) and their homologs having different chlorine numbers and substitution positions are collectively referred to as dioxins.

From the viewpoint of preventing oxidation of the object to be treated,
Heating is preferably performed in a non-oxidizing atmosphere. This can be accomplished by heating the chamber with the pressure reduced or by purging the chamber with a non-oxidizing gas and heating. The latter is preferred from the viewpoint of heating efficiency.

The temperature and pressure in the chamber are adjusted so that desired constituents (or a plurality of constituents) of the object to be processed can be evaporated. Evaporation occurs above the melting point of the component, but the invention heats the component above its boiling point at that pressure. This makes it possible to ensure a sufficiently high vapor pressure of the component to be evaporated. Therefore, efficient component separation can be performed, and the throughput can be improved.

The processing method of the present invention is a processing method for processing an object to be processed having a first component having a first boiling point and a second component having a second boiling point. A target object is introduced, and the temperature and pressure in the hermetic container are adjusted so that the first component in the processing target object is selectively evaporated, and at least a part of the first component is evaporated. Then, the object to be processed is cooled in a non-oxidizing atmosphere.

In the present invention, cooling in a non-oxidizing atmosphere not only lowers the temperature of the object to be treated, but also reduces the surface free energy of the object to be treated by applying a non-oxidizing material to the surface of the object to be treated. It is performed to adsorb gas components.

Thus, the object to be treated whose specific surface area has increased due to evaporation of the predetermined component can be safely taken out. Further, the throughput can be improved by forcibly cooling.

[0021] The processing apparatus of the present invention comprises: an airtight container for holding an object to be processed; temperature adjusting means for adjusting the temperature in the airtight container; pressure adjusting means for adjusting the pressure in the airtight container; Oxygen concentration adjusting means for adjusting the oxygen concentration in the container, and controlling the temperature adjusting means, the pressure adjusting means, and the oxygen concentration adjusting means such that at least a part of the components of the object to be treated evaporates. And a condenser connected to the airtight container and condensing components evaporated from the object to be treated.

In the processing apparatus of the present invention, the control means controls the temperature, the pressure and the oxygen concentration in the airtight container according to the vapor pressure of the evaporation component. The pressure may be adjusted by adjusting the degree of exhaust by the exhaust system and the degree of introduction of the non-oxidizing gas. In particular, under depressurized conditions, it takes time to adjust the temperature of the object to be treated, and it is usually difficult to adjust the degree of the exhaust system, so the pressure is adjusted by the flow rate of the non-oxidizing gas and the oxygen concentration is adjusted. By doing so, evaporation can be actively controlled.
Thus, even when the object to be processed is heterogeneous, the evaporation amount per unit time can be made uniform.

The processing apparatus of the present invention includes an airtight container capable of holding an object to be processed, an exhaust system connected to the airtight container, and an airtight container interposed between the airtight container and the exhaust system. A condenser for condensing a component evaporated from the object to be treated, and a liquid drain provided in the condenser and capable of discharging liquid in the condenser are provided.

By employing such a configuration, in the processing apparatus and the processing method of the present invention, solids and liquids can be separated and collected in the same lot.

A component which is solid at room temperature (25 degrees Celsius) in the object to be treated is recovered as a solid after evaporation (for example, Cd, Zn, Pb, etc.). In addition, components that exist as a liquid at normal temperature in the object to be processed are recovered as a liquid after evaporation (for example, water, oil, mercury, and the like). Therefore, solid and liquid processing can be performed simultaneously in the same chamber from the processing object of the same lot.

In general, the precipitation temperature of solid components is high at room temperature, and low for liquids. These components having different deposition temperatures are deposited in different regions in the condenser by forming an appropriate temperature gradient in the condenser.

According to the present invention, even when the object to be treated contains a component that is liquid at room temperature and a component that is solid at room temperature, it can be separated and recovered in the same chamber.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described more specifically. When removing the metal or non-metal adhered to the article to be treated, the article to be treated is charged into a closed vessel, and the inside of the closed space is depressurized by the pressure reducing means. At the same time as supplying a non-oxidizing gas, performing primary heating by the action of heat transfer by the non-oxidizing gas, reducing the pressure, and then reducing the temperature to a temperature equal to or higher than the boiling point of the metal or nonmetal attached to the article to be treated. Next heating is performed to evaporate the metal and the like.

Thereafter, the vapor is recovered by reducing the pressure in the heated state, and the evaporant is contained and condensed by the condensing means provided in the middle of the recovery path. Then, the non-oxidizing gas is again supplied into the closed vessel to cool the object to be processed, and the gas heated as a result is introduced into a preheating furnace to be used for preheating the unprocessed object.

An inert gas such as nitrogen or argon is used as the non-oxidizing gas to prevent the product from being oxidized when the inside of the closed vessel is pressurized, heated or cooled. It is reasonable to think that the metal, non-metal, etc. attached to the surface of the article to be treated are not a single component but may be a composite composed of several kinds of substances. The vapor pressure at a predetermined temperature should be considered with a certain range, and it is preferable to select the degree of reduced pressure (vacuum) in the closed space, the heating temperature, and the degree of pressurization of the inert gas.

Next, an example of an apparatus used to carry out the present invention will be described with reference to the drawings. The cleaning apparatus shown in FIG. 1 is roughly divided into a closed container 3 having a closed space 2 into which the article to be treated 1 is to be charged, and a temperature of a substance attached to the article to be treated 1 in the closed vessel 3 is increased. A heating element 4 as a heating means communicates with the inside of the closed vessel 3, and a condenser 5 as a condensing means for condensing evaporants removed from the article to be processed 1, and via the condenser 5 The closed container 3
A decompression pump 6 as a decompression means for decompressing the inside, a gas cylinder 7 as a pressurization means for pressurizing the inside of the closed vessel 3 with a non-oxidizing gas, and a nitrogen gas for cooling the heated article 1 to be processed And a preheating furnace 31 for utilizing the nitrogen gas for preheating the processed product.

More specifically, the closed container 3 has a rear heat-insulating door 14 with a heat-insulating material 13 attached to one end side of a container body portion provided with a heat-insulating material 12 outside a hollow retort 11. A front heat-insulating door 16 with a heat-insulating material 15 is attached to the other end side of the container body, and a front door 17 that can be opened and closed is arranged at an opening 16a of the front heat-insulating door 16, so that the closed space 2 is formed inside. Formed. A stirrer 21 is installed on the upper part of the closed vessel 3, and a heating element 4 for heating and raising the temperature of the closed space 2 is provided. The condenser 5 communicates with the closed space 2 via a pipe 25 and communicates with the decompression pump 6 via a pipe 26. The pressure reducing pump 6 is provided with an exhaust pipe 27.
The nitrogen gas cylinder 7 is connected to the closed container 3 via a pipe 30 provided with a pressure regulating valve 28 and a pressure gauge 29 on the way.

Next, a method of cleaning using the above-described cleaning device will be described. After the front door 17 is opened and the article 1 to be processed is loaded into the closed container 3, the front door 17 is lowered and opened. The section 16a is closed, and the vacuum (vacuum) pump 6 is operated to reduce the pressure in the closed space 2 of the closed vessel 3 to about 10 @ -2 to 10 @ -4 Torr. The stirrer 21 is operated, the atmosphere is agitated, the primary heating is performed by the heating element 4, and the temperature of the article to be processed 1 is heated to a certain temperature (a temperature that does not evaporate too much) by the action of heat transfer by nitrogen gas.

Then, the pressure is reduced again, and secondary heating is performed by the action of the heating element 4 to evaporate the deposits on the article 1 to be processed. The evaporant is stored in the condenser 5 and condensed.
Thereafter, it is pressurized and cooled with nitrogen gas, and the somewhat heated nitrogen gas is introduced into the preheating furnace 32 and used for preheating the article 1 to be processed. FIG. 2 shows the pressure in the closed space 2 and the article 1 to be treated.
Is a change in temperature over time. The cooled article to be processed 1 is taken out by opening the front door 17.

FIG. 3 is a diagram schematically showing an example of the configuration of the processing apparatus of the present invention. This processing apparatus includes a processing object 10
Chamber 10 which can be introduced and kept airtight
3, an exhaust system having a pressure reducing pump 106 for reducing the pressure in the chamber, a non-oxidizing gas supply system for increasing the pressure in the chamber and adjusting the oxygen concentration in the chamber 103, and a non-oxidizing gas from the chamber 103. Recovery of the reactive gas,
A non-oxidizing gas reservoir 131 that can be circulated to the chamber 103 after adjusting the temperature is provided. An exhaust system is provided in the reservoir 131, and the pressure in the reservoir 131 is reduced to reduce the pressure in the chamber 103.
Acts as a pressure buffer for

In the chamber 103, a heat insulating material 112 is provided on an inner surface of a frame 109, and a retort (muffle) 111 is further provided on the inner surface. In addition, a heat insulating material 113 is provided on one end side of the chamber body portion in the chamber 103.
At the same time, a rear heat insulating door 114 backed by a heat insulating material 115 is mounted on the other end of the chamber main body. Front door 1
17 and 114 are arranged to form the hermetic region 102 inside. A heating element 4 for heating the inside of the chamber is provided in the chamber 103, and a stirrer 121 is provided above the chamber 103. With such a configuration, the pressure in the chamber can be controlled and the temperature distribution in the chamber can be made uniform.
Therefore, the condensation of the evaporant in the chamber can be prevented.

A decompression pump 106 is provided in communication with the airtight area of the chamber 103 for reducing the pressure in the chamber. 127 is an exhaust pipe.

The airtight area 10 is provided between the chamber 103 and the vacuum pump through a pipe 125 and a valve 151.
A condenser 105 is provided, which communicates with the fuel cell 2 and condenses and collects components evaporated from the processing object 101. Further, the condenser 105 is provided with a liquid drain 152 for discharging a liquid component (for example, water, oil, mercury, etc.) condensed inside. As a result, in the present invention, liquid components such as water and oil evaporated from the object to be treated and solid components such as metals can be separated and collected in the same lot. In other words, objects to be processed including a liquid component and a solid component can be processed in the same chamber and in the same batch.

Separately from the exhaust system having the condenser 105, the chamber 103 is pressurized by introducing a non-oxidizing gas into the chamber 103 and nitrogen and rare gas for adjusting the oxygen concentration in the hermetic zone. A gas cylinder 107 such as gas is connected via a valve 153. 128 is a pressure regulating valve, and 129 is a pressure gauge.

Further, the chamber 103 includes a chamber 1
There is a reservoir 131 that can collect a non-oxidizing gas from the gas chamber 03, adjust the temperature, and supply the gas to the chamber. The chamber 103 and the reservoir 131 are connected to the valve 13
3. Connected via a heater 132. Accordingly, it is possible to prevent the constituent components of the processing target object 101 from being oxidized, reduce waste of non-oxidizing gas used for adjusting the pressure and the oxygen concentration, and improve the processing productivity.

As described above, according to the present invention, a carrier gas such as a rare gas or a nitrogen gas used for cooling gas of an object to be treated, a purge gas for preventing oxidation at the time of heating, and adjusting (pressurizing) the pressure in the chamber is supplied to the chamber. The inside and the reservoir can be circulated and used. As a result, the usage fee of the carrier gas can be reduced, which can further contribute to resource saving.

The reservoir 131 is provided with a pressure reducing pump 154 via a valve 155 as described above. That is, the reservoir 131 has not only a non-oxidizing gas storage but also a pressure adjusting function in the chamber. For example, the object to be processed is heated in the chamber 103 using a non-oxidizing gas as a medium. At this time, the reservoir 131
Opens the valve 155 to reduce the pressure. And valve 1
By closing the valve 55 and opening the valve between the chamber 103 and the reservoir 131, a part of the non-oxidizing gas in the chamber 103 can be recovered, and the pressure in the chamber 103 can be reduced. Therefore, components such as metals having a lower vapor pressure and a higher boiling point can be more effectively evaporated.

FIG. 4 is a diagram for explaining an example of the processing method of the present invention. First, the processing target object 101 is introduced into the chamber 103, and the chamber 103 is sealed.

Then, the inside of the chamber 103 is about 10-1 To
The pressure inside the chamber 103 is reduced by reducing the pressure to about rr.
Thereby, oxidation of the object to be treated can be suppressed.

Then, a non-oxidizing gas such as nitrogen or a rare gas is introduced into the chamber 103, and 780
Pressurize to about rr. Further, the inside of the chamber is heated.
By heating to about 100 degrees or more, water in the object to be treated evaporates and condenses in the condenser. At this time, by adjusting the pressure in the chamber to a pressure slightly higher than the atmospheric pressure, a liquid component such as condensed moisture can be extracted from the drain 152.

If valves are provided between the chamber 103 and the condenser 105 and between the condenser 105 and the pressure reducing pump 106, the pressure in the chamber 103 and the pressure in the condenser 1 are reduced.
05 can be controlled independently. With this configuration, the liquid can be discharged from the condenser even when the pressure in the chamber is negative.

Next, for example, the pressure in the chamber 103 is reduced to about 500 Torr. At this stage, the vapor pressure is lower than that of water, such as oil (including grease), Hg, etc.
The components are evaporated and recovered. In this example, the pressure in the chamber is reduced, but this step may be performed at atmospheric pressure or under pressure. In this case, the evaporation temperature will be higher.

Next, the inside of the chamber 103 is pressurized until the pressure becomes slightly higher than the atmospheric pressure (for example, 780 To
rr) Collect oil, mercury, etc. condensed in the condenser. This allows components with relatively low vapor pressure (eg, water, oil,
Liquid component such as mercury) can be removed, and the pressure in the chamber can be reduced more effectively in a later step. Also, the load on the exhaust system can be reduced.

Then, the pressure in the chamber is reduced to about 10 −2 Torr, and the object to be treated is heated to a temperature equal to or higher than the boiling point of the desired constituent component at the pressure.
Zn and Pb are evaporated and collected. By adjusting the temperature and pressure in the chamber, desired constituents can be selectively evaporated and recovered. This pressure reduction may use the reservoir 131 as an aid as described above.

When the solid components in the object to be treated are evaporated and recovered under reduced pressure, the object to be treated is in a state of having a very large surface and a large (excessive) surface free energy. Therefore, it is very dangerous to remove the object to be processed from the chamber into the atmosphere.
For example, after evaporating and recovering zinc from a zinc steel sheet, when the object to be treated is taken out of the chamber as it is,
The object to be treated, consisting mainly of iron, ignited violently. The components condensed in the condenser are in the same state, and powders (fine particles, ultra fine particles) such as Mg, Al, Zn, etc., ignite even at room temperature.

Therefore, in order to avoid danger, a non-oxidizing gas such as nitrogen or a rare gas is introduced into the chamber or the condenser to forcibly cool the object to be treated and to obtain a non-oxidizing gas component. It is important to reduce the surface free energy of the object to be treated by adsorbing the like.

As described above, by forcibly cooling the object to be processed after the evaporation processing, not only danger can be prevented but also the throughput of the processing can be improved.

In order to introduce the constituents of the object to be processed evaporated in the chamber 103 into the condenser, it is necessary to appropriately manage the temperature distribution in the chamber.
This is because, if there is temperature unevenness in the chamber and there is a region where the temperature is low, the evaporated components are condensed in that region.

For this reason, if it is attempted to introduce the vaporized substance evaporated from the object to be treated by the carrier gas such as N2 into the condenser, the pressure in the chamber does not become sufficiently low. Therefore, the object to be treated must be heated to a high temperature.

In the present invention, a muffle (retort) is provided on the inner wall of the chamber. By employing such a configuration, the temperature distribution in the chamber can be made more uniform. Further, the vaporized component can be led to the condenser without introducing the carrier gas. Therefore, the constituent components can be more efficiently evaporated from the object to be processed, and the energy efficiency can be improved.

In the present invention, the constituents of the object to be treated are heated to a temperature higher than the boiling point thereof to evaporate and recover.

Above the melting point of the constituent, the constituent evaporates, but the vapor pressure is low, so that the recovery time becomes longer or the pressure in the chamber must be lowered.

Further, when the constituent component which is still solid at a certain temperature and the evaporating component are integrated like an alloy, it is not possible to secure the path of the evaporating component to the surface of the object to be treated by the separation above the melting point. Insufficient and inefficient.

In the present invention, a sufficient vapor pressure can be obtained by heating above the boiling point of the constituents of the object to be treated and evaporating the constituents. Therefore, the time required for evaporating the components to be recovered can be reduced, and the throughput can be improved.

[0060]

As described above, the present invention is capable of removing metals and non-metals adhering to the surface of an article to be treated without using a special cleaning agent or combustion flame as in the prior art. It can be removed, and because it is cleaned in a closed processing space, there is no concern about pollution and contamination of the working environment.It is not limited to the above metals, non-metals, etc. It has a very excellent effect that the removal can be performed extremely well. Furthermore, the running cost is low, the automation is easy, and the adhered matter is recovered by vacuum evaporation, so that a nearly pure substance is obtained, and the collected material itself can be reused.

[Brief description of the drawings]

FIG. 1 is a systematic explanatory diagram of an apparatus for performing a cleaning method according to the present invention.

FIG. 2 is a graph showing changes over time in the pressure in a sealed space and the temperature of a processing object.

FIG. 3 is a diagram schematically showing an example of the configuration of a processing apparatus according to the present invention.

FIG. 4 is a diagram for explaining an example of processing of a processing target object by the processing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processed article 2 Closed space 3 Closed container 4 Heating element (heating means) 5 Condenser (condensing means) 6 Pressure reducing pump (pressure reducing means) 7 Nitrogen gas cylinder (pressurizing means) 31 Preheating furnace (preheating means)

Claims (4)

[Claims] 1. A treatment comprising a first component that is liquid at room temperature, a second component that is solid at room temperature, and a third component that is solid at room temperature and has a higher boiling point than the second component. In the processing method for processing a target object, the target object is introduced into an airtight container, the target object is heated in a non-oxidizing atmosphere, the pressure in the airtight container is reduced, and the first component is
Alternatively, heating to a temperature equal to or higher than the boiling point of the second component,
Or the second component is evaporated. 2. A first component having a first boiling point and a second component having a first boiling point.
A processing method for processing a processing target object having a second component having a boiling point of: A processing target object is introduced into an airtight container, and the first component in the processing target object is selectively evaporated. A temperature and a pressure in the airtight container are adjusted, and after at least a part of the first component is evaporated, the object to be processed is cooled in a non-oxidizing atmosphere. 3. An airtight container for holding an object to be processed, temperature adjusting means for adjusting the temperature in the airtight container, pressure adjusting means for adjusting the pressure in the airtight container, and oxygen concentration in the airtight container. Oxygen concentration control means for controlling the temperature control means, the pressure control means, and the oxygen concentration control means so that at least a part of the components of the object to be processed evaporates; A condenser connected to a container for condensing components evaporated from the object to be treated. 4. An airtight container capable of holding an object to be processed, an exhaust system connected to the airtight container, interposed between the airtight container and the exhaust system, and evaporating from the object to be processed. A condenser configured to condense the components, and a liquid drain disposed in the condenser and capable of discharging a liquid in the condenser.