Method and device for destroying confidential paper documents

Abstract

The present invention belongs to the technical field of confidential document processing, and specifically is a method and device for destroying paper confidential documents. The device of the present invention includes: a high-temperature treatment chamber for treating paper confidential documents; a nitrogen working fluid generator for providing inert working fluid protection conditions for the high-temperature treatment chamber; a heater for providing high-temperature carbonization energy for the high-temperature treatment chamber; a high-temperature filter for filtering and intercepting dust that may exist in the high-temperature treatment chamber; a paper crushing mechanism for further crushing the carbonized paper; a control component for controlling the temperature and oxygen content in the treatment chamber, and starting and stopping and controlling each sub-equipment. In the present invention, the oxygen content in the high-temperature treatment chamber is controlled below 16.2%; the temperature is controlled to reach 300-800°C, so that the paper can be completely carbonized. The paper powder after carbonization is flushed into the sewer. The device of the present invention has a simple structure, fast processing, and complete destruction of paper confidential documents.

Description

Technical Field

[0001] The present invention belongs to the technical field of confidential document processing, and in particular relates to a method and device for destroying paper confidential documents. Background Art

[0002] Confidential units such as national defense, military, diplomacy, confidential, government agencies, and even enterprises have a large number of confidential documents that need to be destroyed. The purpose of destruction is to make the secret information recorded in the confidential carrier irrecoverable.

[0003] At present, the vast majority of confidential documents and papers are destroyed in a centralized manner. Centralized processing includes: escorting them to boilers or incinerators for incineration by dedicated personnel, and sending them to paper mill pulp pools for pulping, destruction and supervision. There is also the on-site direct destruction method, including: high-precision shredders, simple incinerators and small crushing and pulping machines. The former centralized destruction method is not only troublesome but also consumes a lot of manpower and material resources. Among the latter methods, most shredders break documents into thinner strips and pieces of paper, which poses a risk of recovery. Simple incinerators have environmental problems such as smoke and dust treatment. Small crushing and pulping methods have a series of problems such as slurry viscosity, blockage and high equipment failure rate, making it difficult to simply and effectively dispose of confidential documents on site immediately, and it is even more difficult to ensure that the destruction requirements of important confidential documents are met. A simpler and more effective solution is urgently needed. Summary of the invention

[0004] In view of the above situation, the purpose of the present invention is to provide a simple and effective device and method that can completely destroy paper confidential documents.

[0005] The present invention uses an inert gas protective atmosphere to perform high-temperature carbonization treatment on confidential documents (waste paper), which is different from the traditional incineration process and is a brand-new solution.

[0006] The device for destroying confidential paper documents provided by the present invention comprises:

[0007] (1) at least one high-temperature carbonization treatment chamber for accommodating confidential paper documents to be treated, having at least an entrance for paper documents to be fed in, and the entrance is closable; it also has an interface for inert working medium to enter and discharge, a mechanism for crushing the treated carbonized material, an interface for water source access, and an interface for feeding the treated paper powder and washing water into the sewer, and preferably but not necessarily also includes an attached heat preservation and insulation material layer to reduce energy loss;

[0008] (2) at least one nitrogen working fluid generator connected to the inert working fluid interface of the high temperature treatment chamber to provide inert working fluid protection conditions for the high temperature treatment chamber;

[0009] (3) at least one heater for heating the inert working fluid outputted by the nitrogen working fluid generator to provide high temperature carbonization energy for the high temperature treatment chamber;

[0010] (4) at least one high temperature filter device for intercepting dust that may be present in the high temperature treatment chamber, preferably a self-cleaning filter device, such as a cross-flow filter device;

[0011] (5) A mechanism for further crushing the carbonized paper, which may be a crushing mechanism of various types, for further crushing the carbonized paper to facilitate discharge into the sewer;

[0012] (6) Accessories such as pipes, valves and interfaces for connecting to water sources to flush the carbonized paper powder into the sewer;

[0013] (7) A set of control components for controlling the temperature and oxygen content in the treatment room, and for starting, stopping and controlling each sub-equipment. The design of the control components is easy for a person skilled in the art to do, and will not be described in detail.

[0014] The method for destroying confidential paper documents based on the above device has the following specific steps:

[0015] (1) Send the confidential paper documents to be disposed of from the entrance of the high-temperature carbonization treatment room into the high-temperature carbonization treatment room; close the entrance;

[0016] (2) Turn on the power supply, start the nitrogen working medium generator, start the heater, heat the nitrogen working medium output by the nitrogen working medium generator at a heating rate of 1 to 3°C per minute, and send it into the high-temperature treatment chamber, and control the temperature of the high-temperature treatment chamber at 300 to 800°C, more preferably, at 300 to 500°C; and, at the same time, by adjusting the flow rate of the nitrogen working medium, control the oxygen content in the high-temperature treatment chamber to ≤16.2% until carbonization is completed;

[0017] (3) Maintain oxygen content, filter excess working fluid and possible dust through high-temperature filters, and then discharge them into the sewer;

[0018] (4) If the high-temperature filter is clogged, use nitrogen as the working medium for backwashing and self-cleaning;

[0019] (5) After the treatment is completed, the heater is turned off and the heater is stopped;

[0020] (6) Turn off the nitrogen working fluid generator and stop supplying nitrogen working fluid;

[0021] (7) Start the paper shredding mechanism and introduce water to flush the carbonized paper powder into the sewer.

[0022] As mentioned above, the disposal process is completed.

[0023] In the present invention, a heater provides a heat source, and an inert working fluid is used as a carrier to bring the heat source into a high-temperature carbonization treatment chamber. Under the protection of nitrogen working fluid, the confidential documents in the treatment chamber are carbonized at a high temperature of about 300 to 800°C, more preferably, at a high temperature of 300 to 500°C.

[0024] Since the high-temperature treatment chamber is protected by nitrogen working fluid, and the high-temperature treatment chamber continuously maintains a "special normal-pressure low-oxygen environment" with an oxygen content of less than 16.2% (v / v, volume percentage), the "special normal-pressure low-oxygen environment" can effectively inhibit the chain reaction of the combustion process, avoid open flame combustion, and avoid the occurrence of violent oxidation processes; only because of the high temperature generated by the heat source, the paper in the treatment chamber completes high-temperature carbonization and cracking, and the working fluid, carbonization and cracking The cracking gas (mainly a small amount of methane, carbon monoxide and other gases) is filtered through a high-temperature filter and directly discharged into the sewer together with the carbonized paper powder; Among them, the high-temperature filter can also be self-cleaned by backwashing with nitrogen working fluid when it is blocked due to long-term operation, and the paper waste after carbonization is connected to the water source after being crushed in the crushing treatment chamber and flushed into the sewer to complete the entire disposal process.

[0025] The device of the present invention has simple structure, fast processing and complete destruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the process flow of the device of the present invention.

[0027] Figure 2 These are photos of the actual objects in the experiment in Example 1. From left to right, they are the morphologies of the paper sheets after being kept warm for two hours at instrument temperatures of 200°C, 250°C, 275°C, 300°C, and 400°C.

[0028] Numbers in the figure: 1 is the paper feeding inlet, 2 is the nitrogen generator working medium backflush inlet, 3 is the nitrogen generator, 4 is the heater, 5 is the high-temperature carbonization treatment chamber, 6 is the high-temperature filter, 7 is the water source inlet, 8 is the crushing mechanism, 9 is the working medium discharge pipe, 10 is the sewer pipe, 11 is the sensor component (temperature, oxygen content, etc. detection sensor, etc.), 12 is the controller. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0030] The accompanying drawings are simplified schematic diagrams, in which:

[0031] Surrounding the high temperature treatment chamber 5, typically, is a container that can withstand high temperature conditions, including preferred but not necessary insulation measures. The container can be fed with confidential papers to be destroyed from 1. After the papers are fed in, the container is restored to a closed state and the nitrogen working fluid generated by the nitrogen generator 3 is used. Usually, the nitrogen component of the working fluid is about 95-99.99% nitrogen. At the same time, the flow rate of the working fluid is designed to bring the heat energy generated by the heater 4 into the high temperature treatment chamber 5 at least for a certain period of time, and create a "special normal pressure low oxygen environment" with an oxygen content of less than 16.2% (v / v, volume percentage) for the high temperature treatment chamber 5, as well as sufficient energy to carbonize the papers to be destroyed.

[0032] Regarding the carbonization of confidential documents (waste paper containing confidential information), the main components of paper are plant cellulose and auxiliary materials such as fillers, glue and dyes introduced in the papermaking process. The composition is complex. In order to achieve high-temperature carbonization and avoid oxidation reactions, it is well known that combustion and explosion must have three elements at the same time: ① combustion aid, ② combustible material, and ③ excitation energy, among which:

[0033] The combustion aid is also the oxidant, that is, oxygen. Normal air contains about 21% (v / v) oxygen.

[0034] Combustibles: all combustible substances, oils, carbon-containing materials, etc. in the target space;

[0035] Excitation energy, typically temperature or open flame, mainly in the form of:

[0036] Mechanical energy: such as friction, impact, adiabatic compression, shock waves;

[0037] Thermal energy: such as flame, high temperature gas, radiation;

[0038] Electrical energy: such as electric sparks, arcs, and static electricity;

[0039] Light energy: such as ultraviolet and infrared heating;

[0040] Chemical energy: such as exothermic reactions of decomposition, oxidation, and polymerization; catalysts, etc.

[0041] When combustibles are mixed with oxygen and there is an excitation energy source, that is, when the "three elements" are present at the same time, combustion will occur; actual research shows that in addition to the above three elements, there is a fourth element to maintain a stable and sustainable combustion process (chemical reaction process), which is also the most easily overlooked element, namely: uninhibited chain reaction. In theory, as long as one of the above four elements is removed, the combustion process becomes unsustainable and the oxidation reaction will be inhibited. In normal air, the volume percentage of oxygen is about 21%, nitrogen is 78%, and other gases account for about 1%. Scientific experiments have shown that as long as the oxygen concentration is lower than 16.2% (hypoxia), the fire can no longer be ignited and the combustion can no longer continue. The mechanism is: the difference in oxygen concentration reduces the availability of oxygen to support combustion, which is caused by the interference of nitrogen molecules on the kinetic properties of oxygen molecules. The increase in the density of nitrogen molecules provides a "buffer" that hinders the use of oxygen.

[0042] Therefore, by continuously supplying nitrogen working medium into the high temperature treatment chamber 5 to control the oxygen concentration in the high temperature treatment chamber, the combustion process can be effectively suppressed, thereby actively controlling and avoiding the oxidation reaction. Only due to the high temperature generated by the external heater as the heat source, the paper is heated to the carbonization process temperature point of the paper in the high temperature treatment chamber (usually, the paper can be completely carbonized at about 300-800°C, more preferably, it is carbonized at 300-500°C. Typically, an adjustable temperature range is used in actual device design to meet the disposal requirements of a wider range of different types of waste paper). In the high temperature treatment chamber 5, due to the injection of nitrogen working medium, the treatment space will continue to maintain a "special normal pressure low oxygen environment" with an oxygen content of less than 16.2% (v / v, volume percentage). This "special normal pressure and low oxygen environment" can effectively inhibit the chain reaction of the combustion process, avoid open flame combustion, and avoid the occurrence of the oxidation process. Only because of the high temperature generated by the heat source, the paper can complete high-temperature carbonization and cracking. The working medium, carbonization and cracking may form cracking gas (mainly a small amount of methane, carbon monoxide and other gases) can be filtered out of dust by the high-temperature filter 6 and then discharged as a working medium, and directly connected to the sewer; at the same time, the paper powder after high-temperature carbonization treatment will also be discharged into the sewer due to the introduced water source.

[0043] Different from the traditional incineration system, the present invention is based on a high-temperature smokeless carbonization process under the protection of inert working fluids. It can not only completely destroy the waste paper into powder and make it irreversible, but also eliminate the large amount of smoke and dust caused by open flame combustion, effectively overcoming the technical defects of traditional disposal technology. As an on-site disposal facility, the waste after the disposal process is completed is directly discharged into the sewer with the water source, which is efficient, convenient, fast, safe and environmentally friendly.

[0044] Example 1

[0045] High temperature carbonization of ordinary printing paper:

[0046] (1) Take an alumina ceramic crucible with a diameter of 50 mm, a height of 50 mm, and a wall thickness of 3 mm, put in shredded A4 paper, and then put in a 60*60*3 mm alumina semicircular crucible boat, and place it in the center of the tube furnace; put a 70*70*4 mm crucible at the outlet to block most of the opening, leaving only a 1-2 mm crescent-shaped gap to keep the gas flowing;

[0047] (2) Gas flow, nitrogen flow rate / air flow rate are both set to 0.5L / min

[0048] (3) Set the temperature program and start heating: increase the temperature from room temperature to 100 degrees at a rate of 1 degree per minute, and then increase the temperature to the set temperature at a rate of 3 degrees per minute. After keeping warm for 2 hours, cool it down naturally to room temperature and then take it out to observe the condition of the paper.

[0049] Figure 2 These are actual photos of the above experiment. From left to right, they are the morphologies of the paper after being kept warm for two hours at instrument temperatures of 200°C, 250°C, 275°C, 300°C, and 400°C.

[0050] Table 1 is a summary of the phenomena under various experimental conditions

[0051] .

[0052] Example 2

[0053] 500 sheets of A4 waste paper (temporarily 70g / m 2 Each sheet weighs about 4.366g), and it is hoped that the waste paper will be carbonized smokelessly within 2 hours, broken into pieces and flushed into the sewer. The waste paper is carbonized at high temperature under an inert gas atmosphere:

[0054] In order to meet the disposal requirements of 500 sheets of A4 waste paper (temporarily calculated at 70g / m2, each sheet is about 4.366g, and the total weight is 2.183kg), the working state of the disposal room should meet the requirements of not less than a load-bearing capacity of 2.183kg and an effective volume of not less than 500 sheets of A4 waste paper. The high-temperature disposal room is designed with a size of Ф400×400 (mm) to meet the requirements. At the same time, in order to facilitate the placement of paper and convenient delivery to the shredding disposal room after carbonization, the high-temperature working temperature resistance is based on working conditions above 800℃ and the design conditions of the surface temperature not higher than 50℃, and the structural design is reserved for nitrogen working fluid, water source inlet and outlet, etc.

[0055] At the same time, the paper is heated to the carbonization process temperature point of the paper in the high-temperature treatment chamber (usually, as tested above, the paper can be completely carbonized within 500°C, and the design adopts an adjustable temperature range of 300-500°C to adapt to the disposal requirements of a wider range of different types of waste paper). In the treatment chamber, because nitrogen working fluid is injected into the high-temperature treatment chamber, the treatment space will continue to maintain a "special normal-pressure low-oxygen environment" with an oxygen content of less than 16.2% (v / v, volume percentage). The nitrogen working fluid flow, purity and required heat source are all designed and selected as per the known technology.

[0056] At the same time, for possible smoke and dust, a self-cleaning cross-flow nitrogen working medium back-blowing self-cleaning high-temperature filter is used, crushing equipment is selected, and material access, water source access and flushing and discharge structures are designed. The equipment composition is as follows:

[0057] .

[0058] The main utility consumption and equipment physical characteristics are listed in the following table:

[0059] .

[0060] According to the steps of the present invention, 500 sheets of A4 waste paper can be completely carbonized into powder within 2 hours, and the waste after the disposal process is completed can be directly discharged into the sewer along with the water source, which is efficient, convenient, fast, safe and environmentally friendly.

[0061] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A method for destroying confidential paper documents, characterized in that: The devices used to destroy confidential paper documents include: (1) at least one high-temperature carbonization treatment chamber for accommodating confidential paper documents to be treated; the high-temperature carbonization treatment chamber has an entrance for feeding paper documents, which entrance is closable; it also has an interface for inert working medium to enter and discharge, an interface for water source access, and an interface for feeding treated paper powder and washing water into a sewer; (2) at least one nitrogen working medium generator connected to the inert working medium interface of the high temperature carbonization treatment chamber to provide inert working medium protection conditions for the high temperature carbonization treatment chamber; (3) at least one heater for heating the inert working fluid outputted by the nitrogen working fluid generator to provide high-temperature carbonization energy for the high-temperature carbonization treatment chamber; (4) At least one high-temperature filtering device to filter and retain dust that may be present in the high-temperature carbonization treatment chamber; (5) A mechanism for further crushing the carbonized paper to facilitate discharge into the sewer; (6) Pipes, valves and interfaces that can be connected to a water source to flush the carbonized paper powder into the sewer; (7) Controller, used to control the temperature and oxygen content in the high-temperature carbonization treatment room, and to start, stop and control each sub-equipment; The specific steps of the method are as follows: (1) Send the confidential paper documents to be disposed of from the entrance of the high-temperature carbonization treatment room into the high-temperature carbonization treatment room; close the entrance; (2) Turn on the power supply, start the nitrogen working medium generator, start the heater, heat the nitrogen working medium output by the nitrogen working medium generator at a heating rate of 1 to 3°C per minute, and send it into the high-temperature carbonization treatment chamber, and control the temperature of the high-temperature carbonization treatment chamber at 300 to 800°C; and, at the same time, by adjusting the flow rate of the nitrogen working medium, control the oxygen content in the high-temperature carbonization treatment chamber to a volume percentage of ≤16.2% until carbonization is completed; (3) Maintain oxygen content, filter excess working fluid and possible dust through high-temperature filtration devices, and then discharge them into the sewer; (4) If the high-temperature filter device is clogged, use nitrogen as the working medium for backwashing and self-cleaning; (5) After the treatment is completed, the heater is turned off and the heater is stopped; (6) Turn off the nitrogen working fluid generator and stop supplying nitrogen working fluid; (7) Start the paper shredding mechanism and introduce water to flush the carbonized paper powder into the sewer.

2. The method for destroying confidential paper documents according to claim 1, characterized in that: The high temperature carbonization treatment chamber is also provided with a heat preservation and thermal insulation material layer.

3. The method for destroying confidential paper documents according to claim 1, characterized in that: The high temperature filtering device is a cross-flow filtering device.

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