JPH05503571A - Plasma heating with closed circulation system - Google Patents

Abstract

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

Description

[Detailed description of the invention] Plasma heating with closed circulation system This invention describes the use of plasma arcs to heat gases, liquids, and solid materials. It is related to business. More specifically, the invention provides this method in a closed circulatory system. This relates to heating by plasma arc, such as:

As is known in the art, plasma arcs were initially Commercializes nitrogen-based gases such as No, No2, and N2O3 called “(noxe’s)”. It was used for commercial production. That is, a gas such as air has 4 to 50 It was sent into a plasma arc reaction chamber at a reaction temperature of 00°C. fertilizer production Along with this, highly reliable and reliable reactor structures have been developed. parkland - Furnace or heater named Birkeland-Eide (BE H) was used commercially for almost 35 years (1905-1940).

In recent years, heated manual disposal of industrial gases used in chemical processing, for example A new industrial application using plasma arc is proposed for the destruction of objects. There is. The benefits of using a plasma arc furnace are that it eliminates pollution from fossil fuels and 4-500 as highly quality heat, with most energy regeneration potential. It has the ability to reach extremely high temperatures of 0°C.

Thus, there are a number of patented plasma arc furnaces and methods for such uses. For example, recently, Norwegian patent nos. 161759 and 162 No. 260 is known.

Plasma is a state in which a gas with a chemical structure breaks its molecular bonds or its atoms are polarized. It is described as a state in which one reaches a state of sexualization. Plasma is An electrically neutral gas molecule whose bond has been broken by a plus ion and a minus electron. formed by a mixture of Thus, at 4000°C or is a viscous state at higher temperatures.

As mentioned above, recently, industrial gas heating used in the processing of certain steel materials has been Plasma torches are known for industrial and industrial chemical processing. more interested A recent application that seems appealing is for the destruction of problematic wastes at high temperatures. It's a good thing.

However, the use of plasma arc equipment for the above applications requires that it There are certain fundamental difficulties when operating as a normal flow system.

First, if oxygen and nitrogen exist simultaneously in the plasmasphere, Noxes are not present. It will inevitably happen.

Second, if the material to be destroyed is fed directly into or upstream of the plasma sphere, Stability is affected and the furnace may close or shut down uncontrollably.

According to one known method, the formation of Noxes occurs when the flow of gas through the furnace is reduced and prevented when

Although such methods may be applicable to specific processes, they are It is inappropriate to do so.

The use of significant amounts of steam is uneconomical and not appropriate from an energy consumption point of view.

Furthermore, the presence of significant amounts of moisture impedes reaction movement in the reaction chamber.

According to this invention, the plasma arc integrated with the closed loop and used only for heating By constructing a gas closed circulation system with a gas furnace, plasma Improved heat utilization is provided. A special chemical reactor serves as the reactive part of the system. A cooler is introduced downstream of the reactor, thereby creating a closed-loop system. consists of a high-temperature section and a low-temperature section circuit.

The basics of loop systems concern gas composition, pressure and temperature, as well as reactant gases and Similarly, the carrier gas is operated under controlled gas conditions.

The carrier gas can be provided from an external gas source and supplied continuously into the system, or it can be supplied in a closed system. It may also be a gas that is pumped in the loop reaction zone.

Other basic and characteristic configurations of the closed loop system are described in claims 1 to 5 of the claims. It is listed.

This closed-loop system, along with drawings, can be used on an industrial scale for waste combustion and destruction. It is explained as being used as a processing step. And, in Figure 1, park club A closed-loop flow diagram of the waste treatment of End-Aid (BE) is shown, while Fig. 2 shows the BE waste treatment closed loop for dioxin waste combustion. There is. The main elements of the closed loop system are the plasma reactor 1, which produces steam or hot water; gas blower or compressor 4 and heat exchanger/cooler 3; This is the separation reactor 2.

The gas closed loop consists of two major temperature zones. That is, for example 10 It has a temperature suitable for producing combustion reactions and chemical reactions that require temperatures between 00 and 2000 degrees Celsius. high temperature zone, the temperature is lowered, suitable for e.g. 300-500℃ gas blower This is a low temperature zone where the maximum temperature is limited.

In a gas closed loop or circuit, a suitable carrier gas or circulating gas B is Applied to related processes. If a special reaction gas is used , which is introduced as A.

The group of nitrogen-based gases in the plasma reactor allows the presence of 02 and N2 in the reactor at the same time. can be reduced and avoided by not having If air is used as a reactant gas, is to be used, the free 02 circulating gas in the furnace 1 reacts with the plasma furnace. Obtained by introducing air A from the reception room, the added air is the theoretical amount of oxygen. secure supplies. Instead, a conventional catalyst 5 (baladium) is installed in the cold zone. can be included. This results in a surplus of O! For example, catalysis with methanol It is removed by medium combustion. Ultimately, the BE closed-loop system in Figure 1 The combustion gas passes through a cooler/condenser 6 with an outlet and a special outlet for sediment. It has an exit port for the

Combustion and other forms of chemical reactions are controlled by the stoichiometric amount of reactant gases such as Ol Therefore, the electrical energy consumption in the plasma furnace can be minimized, and the The release (outflow) of gas and energy into the environment can be minimized. This thing is Furthermore, 100% of the total electrical energy consumption is actually recovered as heat. It will be done.

The energy balance is the electrical energy consumed and used and the reaction energy The plus/minus of energy is thermal energy, i.e. thermal energy in the form of steam or hot water. energy, which occurs when the same amount of energy is removed from a circuit in succession. Since it is balanced, it will be maintained.

The balance of mass is determined by the amount added as a gaseous material, as a liquid material, and as a solid material. The amount of reaction products and lost carrier gas equal to the mass of Therefore, it is maintained by the system.

In contrast to open systems, closed-loop systems use expensive carriers such as N2, A and CO2. Enables use of Agus. Such gas spills and losses are kept at low levels. In some cases, the level is almost zero.

The strength of the reaction is easily controlled by the percentage of reactive gas in the circulating gas can be done.

The reaction chamber is configured according to the type of material to be processed. For example, solid waste For this purpose, it is convenient to use a rotary furnace or a fluidized bed furnace.

For gases and fluids, a serpentine shaped cyclone with a cyclone at its outlet - A chemical reactor is used that utilizes co-flowing reaction tubes.

Example – Destruction of dioxin-containing waste Liquid from a refinery containing 75% water and 25% solid sludge is destroyed. provided to.

Sludge consists of inorganic salts and carbon, initially in the form of activated carbon. Dioxin is absorbed by carbon, and the total pH is 4 or less. from refinery The total amount of fluid is approximately 360 m''/year.

The combustion was carried out in a BE waste treatment closed loop system according to FIG. Separation by stirring The avoided fluid sludge from tank 9 is pumped by pump 8 and heat exchanged. It was preheated by passing through vessel 3 and entered reaction chamber 2 in the form of a serpentine tube. reaction The product was led to a cyclone separator 7 with an ash outlet at the bottom.

Reactant gas is introduced through heat exchanger 3 to preheat the fluid sludge. , then passed through the coiler 10 incorporated into the waste boiler system. . The effluent gas is concentrated H! O and HCI are emitted and the remaining CO is released into the atmosphere. It was passed through the cooler/continentator 6. For the low-temperature part of a closed-loop system A blower or compressor provided provided the necessary gas circulation to the system.

The destruction process is carried out at a temperature of 1500°C or higher in an atmosphere of 02 or air. It was carried out in The reaction products obtained are C02, H2O, HCI and solid ash. (approximately 5% of the total weight of waste) and therefore these gases are It could be used as a circulating gas. (The reaction chamber is a cycle for particulate ash. Formed as a serpentine tube terminating in a long tube. ) Preheating at the entrance of the serpentine tube The recycled waste was introduced into the hot circulating gas. At the same place, 0! will be introduced.

The ash was collected in cyclone 7 and removed batchwise.

The gas passes through a heat exchanger/cooler and is cooled to 400°C before entering gas blower 4. It was. The energy required for the BE upper heater is approximately 50KW, which is evaporated. such as 26KW for heating and 15KW for superheating below 2000℃ It may be divided into This is the total energy required without heat recovery . If the heat is recovered, the energy consumption will be reduced to approximately 25KW. Dew.

abstract This invention describes the use of plasma arcs to heat gases, liquids, and solid materials. It is related to business. A closed loop of gas or gas mixture feeds this closed loop. composition, pressure and temperature to achieve optimal chemical processing of the materials being processed. A controlled closed circulation loop is provided. The theoretical amount of reacting gas is plasma Plasma arc furnace (1) and the reaction chamber (2). Basic carrier gas It is the most suitable for the reason.

Submission of translation of written amendment (Article 184-7, Paragraph 1 of the Patent Law) August 21, 1992

Claims (5)

[Claims] 1. In order to raise the temperature of the reactant gas and/or carrier gas to a predetermined high level. a plasma arc, a reaction chamber, and a gas for transporting gas through the reaction chamber. of a gas or gas mixture in a plasma heating and reaction apparatus consisting of a means of A closed loop to achieve optimal chemical processing of the material fed into this closed loop. A closed circulation loop controlled for composition, pressure and temperature shall be provided. A plasma heating and reaction device characterized by: 2. The theoretical amount of reacting gases is that nitrogen and oxygen are present simultaneously in the plasma arc furnace. In order to avoid high temperature zone and intermediate humidity to allow chemical reactions to occur in the supplied and relevant conditions. There are coolers/heat exchangers (3, 10) to form the zones and also intermediate temperature characterized in that there is a blower (4) for circulating the gas or composite gas. 2. The device according to claim 1. 3. A claim characterized in that the basic carrier gas is optimal for the treatment. The apparatus according to claim 2. 4. The reactive gas is air, 02, H2 or whatever is suitable for it. 3. The device according to claim 2, characterized in that: 5. Closed gas loops are used for chemical production, material drying, electrical steam generation, and For the destruction of waste materials such as ioxins and chlorinated hydrocarbons such as PCBs 3. Device according to claim 2, characterized in that it can be used.