TW553782B - Electrical heating process for treatment of contaminated soil and sludge - Google Patents

Abstract

The present invention provides an electrical heating process for treatment of contaminated soil and sludge comprising (1) using an electric heating furnace as a heating device; (2) using a condensation device to cool off the high temperature gas generated in the electric heating furnace; (3) using a separation device to separate moisture and contaminated material (such as organic herbicide, organic oil, mercury) from gas stream; (4) using a vacuum pump to maintain the electrical heating furnace and the connection pipeline in a negative pressure state to avoid waste gas from escaping out of the electrical furnace; and (5) using a waste gas treatment device to remove the contaminants contained in the waste gas, thereby achieving the merits of simple operation, low cost, low formation of waste gas, and good treatment effect.

Description

The rapid development has caused serious pollution to the environment of Taiwan ’s economic and social population. The conservation of soil in Taiwan has become increasingly important. Yes, it was announced on January 2 that "the determination of soil and ground conservation soil conservation work is important. However, because the soil has a phase adsorption valley of up to 2.5 mole / kg, pollution, it is difficult to make these pollutants very high. At present, there are many processing operations in the city. The reason is that due to soil pollution treatment, the most effective treatment method is currently available. If such a willingness to pollutes the soil, the sewage sludge containing pollutants will also be produced. The metal sludge produced by the chlorine factory, etc., these sludges have to pass through, and then need to be carried out appropriately. In the past few decades, Taiwan ’s industrial bonnet has made a considerable contribution to the 2 steps. The narrow and magical resources are precious, making the earth clock here. The Environmental Protection Agency issued the Law on Remediation of Water Pollution in the Republic of China 89. "It shows that the government: the treatment of soil pollution is also highly absorbent, and the cations in clay to heavy metals Or the organic matter is removed from the soil, and the treatment expenses are also polluted by the soil, but most of them have not yet been treated as too expensive. Therefore, the subject to be implemented is Developed economy, sufficient talents and higher jobs. In addition, in the manufacturing process of various industries, mud, for example, the mercury produced by the petrochemical industry1, mud produced by the electronics industry, and the moisture content after drying can be 5% to 30%, and winter disposal will not cause environmental pollution 553782

The following methods are used for soil and sludge treatment: immobilization, biological leaching, and incineration. Here are some treatment methods such as: (1) Immobilization treatment burial: U.S. EPA's definition of curing method ‘refers to two types of stabilization and stabilization (sotablization)

The technology uses soluble silicate and silicate settling agents (such as cement,: fire, gypsum) as additives to add to the soil or sludge to produce anti-%, i to produce high stability, and easily into powder. Structure, soil or sludge: 3 of the contaminated wood shells will lose mobility due to the following mechanisms, and thus achieve the purpose of treatment. a. mircoencapsulation The soil or sludge particles directly form a box with the additives, and the pollutants cannot escape. b. absorption

The pollutant enters the additive molecular structure layer and forms a binding effect with the additive molecule, so it will not dissolve again. c. Adsorption Adhesion of pollutants on the surface of the additive ’is fixed on the surface of the additive due to the effects of electrostatic force, van der Waals force, and hydrogen bonding. Curing treatment generally requires 3 (U-50% of the added curing agent, after curing

Page 5 553782 V. Description of the invention (3) --- In other words, = will become K5-2 times the original volume, which will cause the buried volume to increase, which is not a good treatment in the case of Taiwan. In addition, due to the physical and chemical effects of the natural environment after the solidified body is buried, the pollutants will still dissolve after a period of time to re-pollute the environment. (2) There are a lot of points for derivation and vacancy. The treatment is based on Treatm (Solid fruit, where the dyeing area is too large, and the pollution is better than ten days.) Only suitable for treatment with oxygen content (ent), mud phase). For the treatment of substances containing trichloroethene, it can be used but is lower than this range. For example, it contains treatment effects, which can cause pollution to soil or sludge, provide suitable nutrition sources, and the metabolism of aquatic organisms consumes organic pollutants. Therefore, it is suitable for the treatment of organic pollutants. The type of treatment can be divided into aerobic treatment and anaerobic treatment. It can be divided into land treatment (Slurry Phase) and solid treatment of sludge containing toxic materials. The sludge treatment method is only in the range of 0.5-10.0mg / kg. If it exceeds this range, it will not be able to effectively use the biologically toxic surrounding organisms. For sludge or soil with less toxic oil, biological treatment can reach but It still takes a long time, taking the No. 6 fuel oil as an example, the degree of decline is 30%-60%. (3) Leaching treatment Use a chelating agent (C he 1 ating Agent) to rinse contaminated soil or sludge. Ligands (Dentate Ligand) and pollutants

Page 6 553782 V. The combined force of the description of the invention (4) enables the pollutants in the soil or sludge to be desorbed and discharged into the liquid phase, and then the flowing water is collected. The effluent water will contain a high concentration of pollutants and must be treated separately. Adsorption is an aggregation phenomenon that occurs at interfacial substances. Its mechanism can be divided into three parts: internal sphere complex (Inner Sphere Complex), external sphere complex (〇uter Sphere Complex), and diffuse ion group (j) iffusi. n I〇n Swarm), the first two are specific adsorption behaviors; the third is the adsorption of pollutants on the outer edge of the ligand by means of electrical adsorption, which is related to the chargeability of the soil or sludge surface and the amount of charge .

EDTA (ethylene diammonium tetraacetic acid) is a commonly used chelating agent, which can form a hexapodal base and therefore has a strong adsorption capacity for heavy metals. When the content in the eluent reaches 292 mg / L, the mercury in the soil can be reduced from 30 mg / kg to 3 mg / degradation rate of 90%. However, the limit of the degradation rate that can be achieved by increasing the concentration of Xie Ren is approximate. After the treatment of this method, the residual mercury concentration in the soil is about g S, which is insufficient to meet the target soil values at home and abroad. (4) Incineration treatment The soil or sludge is directly injected into the incinerator to burn the thermal energy generated by the incinerator. The soil or sludge is added :, = bed phase ", the more common ones are rotation to heat: transfer = to, main The combustion chamber adopts a rotary fumigation furnace, and the ^ :: :: J fuel is passed through the rotary kiln. J Dexun cannot be moved to the ash discharge port, and the incineration material is mixed to reach the kiln incineration.

Page 7 553782 V. Description of the invention (5) It is constructed with high temperature and high alumina materials (fire bricks and refractory mud), with a high temperature resistance of 1 540 ° C, and the ash burning reduction must reach 丨 0%. The secondary combustion chamber burns the main combustion until the incoming combustion gas utilizes excess combustion air and high temperatures. Above c, a residence time of more than 2 seconds is required to effectively oxidize the exhaust gas to carbon dioxide and water vapor.

Fluidization is to use a hot air box to fluidize the quartz sand and make the bed temperature reach above 750.0, and pass the soil or sludge into the fluidized bed. Organic matter in the sludge is oxidized to carbon dioxide and water vapor. The particle size of the sand in the fluidized bed is about 500-1000, and the loss is about 3% of the amount of the sand bed. The bed size requires 5% of fine sand. The diameter of fine sand is 2.5 times smaller than the diameter of coarse sand, in order to reduce the friction between coarse sand particles, but the proportion of fine sand should not be too high, otherwise it will be short. The inside is carried out of the furnace and carried out (Carry —over). In addition, it is also necessary to pay attention to the water content in the soil or sludge. Over 80% will seriously damage the refractory materials in the hearth. There are many shortcomings of the above-mentioned treatment techniques that need to be improved. They are stated as follows: (1) Immobilization treatment buried a. If the soil or sludge contains special salts, it will cause the solidified body to collapse. b · Decomposition of organic matter in soil or sludge will cause cracks in the solidified body, increase permeability and reduce structural strength. c · A large amount of additives will increase the volume,

553782 V. Description of the invention (6) a —_______ It is quite troublesome, especially in the stage, the final place of this treatment method w = difficult to find in the burial site d. If lime is used as an additive, curing is a big challenge. The curing time. Low body strength and longer e. For the solidification method using paraffin, polyethylene, or leached soil or sludge containing organic soluble Y ^ additives, if nitric acid, chlorate and perchloric acid di 1 dissolve additives, Or contain applicable curing method. | Directional concentration of strong oxidants, no f · Landfill after treatment, metric tons. : Processing unit price is about NT $ 1,2,00 / (2) Biological treatment a. For soils or microorganisms containing heavy metals that cannot decompose heavy metals [/ b, this method is not applicable because b. For many toxic organic substances, agents Microbes can not completely remove: Nongle, pesticides, weeding C. The concentration of organic substances is too high, and it is also solved. When the degree is low, microorganisms cannot; i j organisms are toxic, but there are many restrictions. , Yaba use for metabolic decomposition, because d · biological treatment takes a long time, e =: the concentration of dyes fell to the ring "to even grow bar for several years or more; complex; :: raise, remuneration are not easy. If Timeline of processing. Therefore processing death, affecting page 553782

It is also difficult to predict the effectiveness of treatment due to the complicated growth conditions of microorganisms, which often causes problems for decision makers and treatment designers. (3) Leaching treatment a. Leaching will produce a large amount of waste, which is between 1: 3-1: 2 0, and the high-concentration lotion contained in the waste liquid is tightly bound, combined type substances and leaching. Separation of agents will b. Soil or sludge will sometimes be shaped detergents may be difficult to enter the pollutants which cannot be included c. According to past experience, with a lye of 2-4mg / kg, there are more than 1mg / kg, all of which are insufficient. Soil: Volume ratio of waste liquid I 'These waste liquids need to be reprocessed. Heavy metals or organic substances exist as disks, and it is very difficult to remove these heavy metals or ^. —The machine forms a granule structure, and the water permeability is not within the fine pore diameter of these granules, and it comes out and desorbs. In other words, the soil or sludge is washed, and the residual concentration of pesticide residues in the machine is mostly in the range to meet the soil remediation standards. (4) Incineration treatment a. A large amount of waste gas will be generated. The waste gas contains toxic substances and must be treated. The required waste gas treatment cost is a large proportion of the total treatment cost = it is not worth it. , Possession

b. Higher heat loss. c. Dioxin may be generated in the combustion exhaust gas, causing public resistance. d · Fuel consumption is very high '. A complete fuel supply and delivery system is required. e. Dust collection equipment is needed to collect the escaped fine particles.;.

Page 10 553782 V. Description of the invention (8) f. The residence time of the treatment substance in the incinerator is generally short. Can the pollutants be desorbed from the fine pores of soil or sludge within this short time? Or There is still doubt about the completion of the thermal cracking reaction. However, longer dwell times will consume more fuel. In order to solve the problems of the above-mentioned treatment methods, I proposed heating the soil or sludge with an electric heating furnace, so that the pollutants in it are desorbed or cracked out by heat, and the pollutants are then evacuated to the separation tank and the waste gas treatment equipment for separation and reasoning . The problems that the present invention can solve are as follows: (1) No fuel is used, and no large amount of exhaust gas is generated as in the incineration method, so considerable waste gas treatment equipment costs and operating costs can be saved. (2) The 7L structure of each device is simple, so compared with the incineration method, the initial cost is low and the cost of maintaining thinness can be reduced. (3) Regardless of whether the pollutant is organic or mercury, it can be removed by thermal cracking. Compared with leaching treatment, the treatment result is much more stable and the treatment efficiency is not low. The performance is greatly reduced (4) The treatment time is short. It does not take time for biological treatment. Reason: Step: pure, not for incineration treatment equipment operation; and for biological treatment, it is necessary to treat the soil or sewage. The microbial growth environment is adjusted. Various kinds of mud in the mud are covered for the soil containing pollutants and the new treatment process, that is, make; 553782 V. Description of the invention (9) Warming soil and sludge , So that the pollutants contained in it are desorbed out, to achieve the purpose of treatment. Means to solve the problem First, the theoretical basis of heat treatment of pollutants in soil or sludge is introduced. Taking organic pesticides as an example, domestic common pesticides such as pentachlorophenol, hexachlorobenzene α, cold, r, BHC), DDT and its derivatives (DDT, DDE, _) ° Water of pentachlorophenol Very low solubility, only 14 mg / L at room temperature, and low volatility, only 0.024 mm H g, but volatility will increase sharply at high temperature, and its boiling point is 313QC, which means temperature rise As high as 313 ° C, pentachlorophenol will completely volatilize, and when the temperature exceeds 300 ° C, it is easy to produce thermal cracking reaction. The melting point of benzene hexachloride is 1 12QC (r-BHC), and the half-life of UV light oxidation in an aqueous solution of 90 ~ 95QC is a-BHC 24.2 hours, and r-BHC is 17.4 hours. But easily decomposed when heated. The general characteristics of pesticides can be roughly divided into thermally decomposable and thermally stable types in terms of thermal decomposition. Generally, the thermally decomposable type is between 130 ~ 15 (PC (such as Parazon of organic phosphorus 1 3 0 ~ 1 50 ° C, methylparazon (130 ° C), most of them can be decomposed not more than 300QC. For example, carbamate chlorpyrifos is thermostable, so it must be used at a higher temperature. It can be decomposed, but it will be completely decomposed to 500 C. These pesticides will form organic compounds with smaller molecular weight and higher volatility after cracking. They can be desorbed from soil or sludge at high temperature. Domestic There are also many soils contaminated with organic solvents, such as trichloroethyl

Page 12 553782 V. Description of the invention (olefin) Triene is slightly soluble in water and has a boiling point of 86.7 ° C. Therefore, as long as the heating temperature exceeds this boiling point, it can be theoretically removed from the soil. For heavy metal pollution, volatile mercury can also be removed using thermal desorption. The atomic weight of mercury is 200 · 5 9 and the boiling point is 3 5 6. 9 t. The saturated vapor pressure at 30 is 3 · 968 * 1 0_6 bar, that is, the saturation concentration in the air at normal temperature and pressure is about 4 ppm ( Volume ratio); However, when the temperature increased to 400 ° C, the saturated vapor pressure increased to 2.1 bar, which has exceeded atmospheric pressure. When the temperature increased to 800 ° C, the saturated vapor pressure increased to 106.9 bar, showing As the temperature rises, the volatility of mercury increases sharply. If this chemical property can be used during processing, the mercury in the soil can be effectively removed. However, most of the mercury in the soil does not exist in the form of metallic mercury, but in the form of divalent mercury compounds, such as HgS, HgCl2, HgC03, etc. These compounds will undergo the following reactions at high temperatures:

HgS + 02 — Hg + S02 2HgO — 2Hg + 02 2HgC03 — 2Hg + 2C02 + 02 The theoretical temperature required in the reaction is about 3 6 (TC, however, if the temperature is heated to 6 0 0 ° C-80 0 t, Will improve the recovery and purity of mercury in the soil. These chemical formulas are reversible. During the heating process, lime or iron can be added to make the removal effect better, for example: 2HgS + 4CaO-> 4Hg + 3CaS + CaS04 or

HgS + Fe — Hg + FeS As can be seen from the above description, the use of heat treatment to remove soil or sludge

Page 13 553782

Organic substances and mercury compounds do have their theoretical basis and superiority.

> There are many heating methods. I have specially proposed a heat treatment procedure for heating pollutants in soil or sludge with an electric furnace. The method is to use soil or sludge contaminated with organic pesticides, organic oils, organic solvents, and mercury. The following structures are constructed: (1) Electric heating furnaces are used as heating equipment. Thermal resistance wires are surrounded in the electric heating furnaces. The soil or sludge to be treated is placed in the electric heating furnaces, and there is no barrier between the soil or sludge and the thermal resistance wires. Only air exists. To heat the resistance wire with electric current, and heat the soil or sludge to the desired temperature through the effects of heat convection, heat conduction, and heat radiation; (2) cooling the high-temperature gas generated in the electric furnace by condensation equipment; (3 ) Separating water and gas pollution with separation equipment, substances (such as organic pesticides, organic oils, and mercury) from the air stream, (4) vacuum pumps to keep the electric furnace and connecting pipelines in a negative pressure state to prevent exhaust gas from overflowing from the electric furnace Exhaust; (5) Remove the pollutants contained in the exhaust gas by the exhaust gas treatment equipment. & & The above program has the advantages of simple operation, convenient maintenance, and low exhaust gas. It can greatly reduce the processing cost and achieve the purpose of heat treatment. Taking organic farming as an example, the final furnace temperature should be 40 ° C. If it is treated with mercury-contaminated soil or sludge, the final furnace temperature should be 800 ° C. c, it can be removed.

^ The exhaust gas produced by this method is only water vapor and volatile pollutants contained in soil or sludge, and the amount of exhaust gas is relatively small. Therefore, it should be treated with general exhaust gas treatment equipment, such as activated carbon tanks, exhaust gas treatment equipment costs, and The operating cost is also greatly reduced. Since the amount of exhaust gas has been greatly reduced, it is relatively less likely to cause protests among residents near the treatment plant. °

553782

Function In order to solve the problems faced by the prior art, the present inventors have discussed and tested and proposed the use of an electric furnace for heat treatment of soil and sludge in order to complete the present invention. The following is a description of the month of this hair, and the unit of the next two things, and its role is as follows: The following several (1) electric furnace: heating equipment. Make the material to be treated t the mercury or volatile organic compounds contained in it high; if it is surplus, it will be pound = the inner wall of the heating furnace surrounds the resistance line, there are many types of resistance line: to gas

Need to be different, from °. ° 5-2. Two can test V ίϊί: Generally speaking, the larger the furnace body, the larger the resistance wire diameter, the surface. The heating rate is increased at an hour per hour. If it is too large, the heating time is too long, which increases the loss of artificial spines and increases the cost of electricity f. , Handle costs. If it is too fast, the power required by the electric furnace during thermal heating can be estimated from the following formula: s \ (T— formula (1) where II · Ms Μ. = The temperature in the furnace is increased from T0 (〇C) to Required amount = weight of soil or sludge (kg) = weight of air in electric furnace (kg) 553782 5. Description of the invention (13)

Mw water content in soil or sludge (kg)

Csp = specific heat of dry soil or sludge, if quartz sand, about ap wp

0.8kJ / kg / QC, if it is clay, about 0.89 kJ / kg / ° C: specific heat of dry air is 1.01 kJ / kg / ^ C: specific heat of moisture is 4. 18 kJ / kg / ° C Hw The heat of evaporation of the second water is 226 1 kJ / kg / ° C. However, the actual heat content input through the electric furnace will be lost. It will vary according to the heat insulation effect of the electric furnace, usually a loss of 30% to 70%. Therefore, a safety factor must be added to achieve the desired temperature. The electric power of the electric furnace is equal to the calculated heat demand, multiplied by the safety factor, multiplied by the heating time. In addition, the time required for heat conduction must be estimated to correct the heating time and evaluate whether the temperature in the soil is uniform. The calculation method is as follows: 9 q 1 δΐ V2T + — = ——- l Equation (2) 1 kia {6t where q = Heat flux (W / m2) k = thermal conductivity coefficient, air is 0.0 2 5W / m / ° C, and dry soil is 0.3-3. 0 W / m /. C varies, usually with higher clay and lower sand. a = thermal diffusion coefficient, air is 20.5 * 1 0_6 m2 / s e c, soil is 0.24- 1.2 2 * 1 0_6m2 / sec, usually clay is higher, sand is lower. The subscript i in the formula represents air or soil. Because the electric furnace includes these two parts of the boundary substance, the above formula needs to be divided into two types, and the total heat flux is equal to the individual heat fluxes in the air and soil, that is:

Page 16 553782 V. Description of the invention (14) Formula (3)

i A and the boundary condition is qa

A formula (4) where Q is the output power of the electric furnace (kW), 7 / is the thermal efficiency of the electric furnace, and A is the internal surface area of the electric furnace (m2). The above formula uses the finite element difference or finite element method of the numerical analysis method for analysis. The analysis assumes that the temperature of the soil or sludge and the air interface are the same. (2) Condensing equipment: The high-temperature gas generated in the electric heating furnace is cooled to avoid high temperature from damaging subsequent equipment. Condensing equipment can use water circulation or other cooling methods such as air cooling, liquid nitrogen, etc., who can achieve the cooling effect. If the water circulation type is used, a cooling circulation water tank can be installed to save water consumption. (3) Separation equipment: Separate water vapor, pollutants (such as mercury metal) from the air flow. The separated water and gas are treated separately, and the collected pollutants can be recycled and reused. (4) Vacuum pump: Keep the electric furnace and the connecting pipelines under negative pressure to avoid exhaust gas from overflowing from the electric furnace. The gas flow of the vacuum pump does not need to be too large, but it must maintain a certain vacuum state, at least 100 cm of negative pressure in the water column.

Page 17 553782 V. Description of the invention (15) (5 \ Exhaust gas treatment equipment: remove pollutants contained in exhaust gas. Various activated gas treatment equipment such as activated carbon tank washing tower, absorption tower, catalyst oxidizer, etc. can be used. The characteristics can be adsorbed, removed, absorbed, or oxidized, and the dust particles contained in the exhaust gas can also be removed with a filter bag dust collector, Venturi dust cleaner, and electrostatic dust collector. If an activated carbon tank is used, the tank can be calculated according to the following formula The required size of the body: V = (Co) {βΑνβ Formula (5) where V = adsorption bed speed ma = gas mass flow rate α, / 3 = balance coefficient between activated carbon and adsorbent gas density P ad = adsorption The apparent density of the bed A = the cross-sectional area c of the adsorption bed. = Adsorption saturation concentration After knowing the adsorption bed speed, the adsorption breakthr ugh time is equal to:

V where L is the height of the adsorption bed, 5 is the thickness of the adsorption zone, and the formula (5) for 5 is

Page 18 553782 V. Description of the invention (16) δ K Ap

ITL 4.595

In 1- (0.01) 1 -ι Two ^-1- (0-09) Formula ⑺ K is a function of the film barrier and the effective surface area of the adsorbent, which is between 5 and 50 0 sec-1. The first picture is electrothermal Equipment flow chart of furnace thermal desorption procedure, in which the condensing equipment adopts water circulation type and the exhaust gas treatment equipment adopts activated carbon tank. Example The design, installation, and testing of the heat treatment program of an electric furnace are performed. System = feasibility evaluation, under various operating changes such as system time, the end temperature and heating of various meters have been performed. First, calculate the work required for the electric furnace; τ soil, and test. 60 kg, and the moisture content in the soil is 15% '. If the soil in each batch is divided into 9 kg, and if the length, width and height of the electric furnace are ^, the water in each batch of the electric furnace after removing the soil and water volume, The remaining x 45cm x 60cm will be deducted 0 · 0915m3. In addition, the nature of the soil is turning, and the soil volume is the air volume, which is about 40 ° C. Using formula (1), the two room temperatures can be calculated as 30QC. If the final temperature Q = 60kg X (K89kJ / kg / ° CX (4〇〇 * electric power: 1.001kJ / kg / ° CX (400-30) ... + 3 0) ... + 0 · 0 9 15kg x 9kg x 4. 18 kJ / kg / ° C x (4 〇〇9kg x 2 26 1 kJ / kg + 14.3kW-hr 3〇) ° C =, 5 1 4 27kJ = If the thermal efficiency of the electric furnace is 60%, heating and guarding is 2.5 hours, then required

553782 V. Description of the invention (17): Power = 9. 5 3kW 'Therefore, the electric heating furnace rate used in the test is designed based on this calculation result. 『Hanji ’s power and waste treatment equipment uses activated carbon tanks, and the design work is based on the formula (5). The equilibrium constants between the activated carbon and the organic adsorbate are approximately 180 kg / m3, 2 · 2, and the organic gas flow rate is set to 5 L / min, so the gas mass flow rate is 106 × ΐ〇_ 4; κ is the impedance of the membrane and the effective center of the adsorbent. The more conservative data is 5secrl; the diameter of the activated carbon tank is temporarily set to ^, so the cross-sectional area is 2.83xl0-3m2. In this way, the equation (7) can be used to calculate the occupation (thickness of the adsorption zone), and the calculated 5 is equal to 0.05 mm. The next step is to calculate the bed velocity v, where the apparent density of the activated carbon is 0 kg-1 / M. Using formula (5), ν = 114 x 10-5 m / sec can be obtained. Since two batches of experiments are required, it is estimated that the total time required is about 〇0 hours, so = adsorption leakage time is set to 10 hours, then according to formula (6), the height of the adsorption bed needs to be 0.46 m. M & ^ Based on the above calculation results, the inventors designed the system and method of treating the pollutants in soil and sludge with the electric heating 3 of this embodiment. The electric heating furnace is covered with bricks and bricks with a thickness of 10 cm. The refractory bricks are embedded with nickel-chromium electric resistance wires for 2 minutes. furnace

^ The size is 60cm (H) X 45cm (W) x 45cm (L). The earthen clams are made of ceramic plates. The size of each dish is length, width and height = 1 8cm X 16cm x 6cm. The output power of the electric heating furnace is 10kw, which is 7 horses more than the calculated power: the power source is a three-phase 220 Vo Its. A temperature sensor is installed in the electric furnace to display the temperature in the furnace. The temperature sensor is connected to the electromagnetic switch to control the temperature in the furnace by turning on / off the power.

553782 V. Description of the invention (18) When installing the soil, Lei Yi lifted the furnace cover, put the ceramic transformer plate, and then connected the electricity, furnace, and condensing pipes. The condensing pipe is 12m long and 0.5 inch diameter copper; two steel pipes covered with 1 inch diameter are passed with cooling water in the middle to cool the cold exhaust gas and the temperature of the exhaust gas does not exceed ah. Connected after the condensing tube: 1 pu, 1 continuous pumping to maintain the negative pressure in the electric furnace, and the negative pressure is connected to more than two live columns. The pumping volume is 5L / Dlin. Connect again after vacuum pumping * To adsorb the volatile organic gas contained in the exhaust gas, the chaos after the suction will be directly discharged into the atmosphere. The diameter of the carbon adsorption tank is 6cm. The height of the adsorption bed is _.5m.

The former is based on the highest concentration in the airflow. The second step is to enter the lamp as the day guard. The concentration of the airflow will not remain at the most consistent. The absorption tank leakage time should be longer than 0 hours. Heart, so do not shake with ί ΐ ϊ is only designed and installed for the needs of this case, not-#. The size and function requirements of each device vary depending on the soil (soil, clay) or the characteristics of the pollutants. The inspection method and 4 samples of dimercury analysis were adopted by the EPA announced method NIEA S340 60T, = sulfur :, nitric acid and potassium permanganate were oxidized to divalent mercury 壌 in the middle Πΐ: valence mercury was reduced to protomercury +, and then passed through the gas. Sent to :: Also Lu, quantify it with an atomic absorption spectrometer at a wavelength of 25 3 7 nm. Due to the fact that there is no standard analysis method for the detection of organic matter in China, page 21 553782 V. Description of the invention (19)

1 The organic matter analysis in this soil is carried out by the steps of USEPA USEPA 846 / 8040. The detailed analysis steps are as follows: 1 Establish a calibration line. (1) Prepare an analyte standard: it will contain 100 mg / L standard. The solution was taken out of the refrigerator, and after being warmed, it was diluted to 2, 5, 10, 20, 50, 100, 2000 mg / L, respectively. Take an appropriate amount of the internal standard solution and add it to each concentration of the standard solution, and make the internal standard content of each standard solution 40mg / L. 2 Sample pretreatment (1) Add standard: Take 200mg of standard and add to 5g soil sample. (2) Solvent extraction: add the 10mL of the extracted soil sample (dichloromethane: acetone = 1: 1) to the weighed soil sample, and then sonicate for 2 hours, then filter with a pore size of 0 · 4 5 // m paper . (3) On-machine analysis: Take 1 mL of filtrate, and simultaneously add an inner standard of 40 g // into a sample bottle for analysis. 3Instrument measurement (1) Calibration line confirmation: After injecting a calibration standard (Calibration Check Com p o und), compare it with the calibration line, and 4 check whether the calibration line is shifted. (2) Blank analysis: Take blank solvent and perform blank analysis. (3) Arrange the samples that have been placed in the sample bottle in the automatic sampling device in order, and use the gas chromatograph and electronic capture detector to perform the actual sample analysis according to the set analysis conditions.

Page 22 553782 V. Description of the invention (20) (6) Repeat analysis: Each batch will be tested and analyzed by quality control samples. 4. Soil sample configuration The substance treated in this test is soil, and the soil moisture content is about 15%, and the soil quality is silty fine sand. The configured pollutants are pentachlorophenol and trichloroethylene, or mercury. The configuration method is as follows: (1) Configure standard solutions of pentachlorophenol and trichloroethylene, both of which have a concentration of 5mg / L, and are soluble in acetone. (2) Configure a mercury chloride solution with a concentration of 5mg / L and the solution as water. (3) Dry the clean soil in a cool place. (4) The standard solution of pentachlorophenol and trichloroethylene and mercury chloride solution are poured into the soil, and the weight ratio of the soil to the solution is 1: 0, 1 to make the soil saturated. (5) Place the soil in a fume cupboard for three days to evaporate the acetone in the solution. (6) Seal the soil and let it stand for two weeks to allow the pollutants to be fully adsorbed by the soil. Effect When the test is performed, the soil contaminated with pentachlorophenol and trichloroethylene is treated at a final temperature of 400 Q C; the soil contaminated with mercury is treated at a final temperature of 800 ° C, and it is an effective treatment of mercury in exhaust gas The adsorption tank is changed to be filled with EDTA. The analysis results show that all the organic matter or mercury in the soil has been removed, and all the pollutants are below the detection limit of the above analysis method.

Page 23 553782 V. Description of the invention (21) The push table before the test is shown in Table 1. When the experiment is completed, the heat input is as previously calculated and the experiment is completed, so the heat input is the same as before. Calculate additional pollution than previously estimated. And in the effective adsorption of airflow errors. The required operation is electricity or power generation NT $ 300.00 / public mock, so the unit price is low. According to the theory, the analysis of the concentration of the original soil and the treated soil shows that the time required to heat from 3 0Q C to 4 0 0 C is 2 hours, and the energy is 20 kW-hr, and the actual heating is 14.3 kW. -hr, so the thermal efficiency is 71, which is better than 60%. · The results show that the time required to heat from 30 ° C to 80 ° C is 5 kWh, and the actual heating energy is 32.8 kW-hr, so the thermal efficiency is 6 5 5%, 60% is better. · °, also process = Effective collection of waste gas and waste water, which will not produce pollutants in activated carbon or EDTA adsorption tank during the whole experiment. It also shows that the previous calculation results are correct without treatment. The early price is about N τ $ 4 00 / common sigma, if the machine can be used as a power source, the processing unit price can still be lower, and the industry. If the mercury-contaminated soil is treated, the temperature required is higher and higher, about NT $ 6000 / metric ton, but it is still higher than the solid / dagger method.

553782 V. Description of the invention (22) The first table Contaminants Pentachlorophenol trigas ethylene mercury Original concentration (mg / kg) 1.1 0.9 1.2 After treatment concentration (mg / kg) ND ND ND Detection limit (mg / kg) 0.02 0.01 0.2 Analytical method USEPA SW846 / 8040 USEPA SW846 / 8040 NIEA S340.60T Analytical method recovery rate (%) 110 110 120 Final heating temperature (° C) 400 400 800 Heating time (min) 124 124 312 Power consumption (kW-hr ) 20.6 20.6 32.8 Note: ND indicates that the concentration is below the method detection limit. Page 553782 Brief description of the diagram The first diagram is the equipment flow chart of the thermal desorption process of the electric furnace, in which the condensing equipment adopts the water circulation type and the exhaust gas treatment equipment uses the activated carbon tank, but the specifications and functional requirements of each equipment must be based on Design of individual system units for the pollutants and media being processed. The main functional requirements of each device have already been described as before, so we will not repeat them here.

Page 26

Claims (1)

Second: The revised scope of the patent application after revision gi / sixth, the scope of patent application 1. An electric train step (1) uses the temperature of the thermo-material (2) to cool (3) to separate the solvent (4) (5) A method for heat treatment of pollutants in soil and sludge by using a waste-free furnace (5), including lowering the temperature of the electric furnace to the degassing equipment and mercury, and depleting the condensing equipment from the equipment and mercury air pump gas by electrical treatment As heating equipment, the soil or sludge to be treated is placed in the inner wall of the electric heating furnace every time it is wound with a thermal resistance line to increase the temperature by 100 ° C-200 ° C for one hour. The temperature required for heating is to make it contain Mercury or organic substances in high airflow; cooling high-temperature gas generated in the electric heating furnace; separating water vapor, at least one pollutant selected from organic pesticides, organic oil products, and organics from the airflow; maintaining the electric heating furnace and connecting pipelines Negative pressure to avoid overflow from the furnace; The equipment removes pollutants contained in the exhaust gas. Pollution assessment > 11 Sludge and loam soil 'needs heat treatment', furnace #M, #Heat 1 electric heat. Add the application of the law in the middle of the law. The term is given by the rateable work H = MS * C / (TT;) + M4 * C, (T-1) + team * 圮 +] ^ * (: Which * (1〇0 一 X) Formula (1) Where H = heat required to raise the temperature in the electric furnace from Tq (〇c) to T (〇c) (kJ) 'Ms = weight of soil or sludge (kg), 圪 = weight of air in the electric furnace (kg ), Mw = moisture content in soil or sludge (kg), specific heat of dry soil or sludge, Cap = specific heat of dry air, cwp = specific heat of water, evaporation of secondary water Page 27, M3782, patent application for 圚 heat; In addition # Evaluation: Ϊ Must estimate the time required for heat conduction to correct the heating time and whether the temperature in the soil is uniform. The calculation method is as follows: ___: _ 1_k ia {dt formula (2) In the formula, ^ 1 ~ heat flux, k = thermal conductivity coefficient, _ q, temporarily represents air or soil, because the electric heating furnace contains these two parts of the medium, all the heat flux is equal to the air heat diffusion coefficient quality,… two percent For the work, because the electric heating gas and the above formula need to be divided into two types of individual heat fluxes in the simultaneous soil, namely Σ ^ ι (x, y9z, t) and the boundary conditions are: A ^ in Q is the output of the electric furnace Power ..., surface area inside the furnace. Type AV (3) Type (4) is the thermal efficiency of the electric furnace, and A is the method of heat treatment of soil and sludge in the electric furnace by the electric furnace in item 2 of Shen Shen's patent scope, in which the aforementioned condensation equipment uses an electric furnace == $ Gas produced in the cooling; Condensing equipment can use the water circulation type, | A ★ Any one of the liquid nitrogen, A, check, enter " gas type 5 or J million type to achieve the effect of the cold part. 553782 VI. Application scope of patents ~~~ 一 '^^ ——--- 4. If the method of applying for dyeing item No. 3 in the scope of patent application, straight middle needles; heat treatment soil and sludge in Xixi furnace Miscellaneous. \ Eight is to separate the water vapor, pollutants and two from the equipment: = Separate the water vapor and treat it separately, and the negative can be recycled and reused. &Amp; & method of heat treatment of soil and sludge in electric furnace in item 4 of the patent, wherein the aforementioned vacuum pump keeps the electric furnace and connecting pipelines in a negative pressure state to prevent exhaust gas from overflowing from the electric furnace. Cavity & Ming patent No. 4 scope of the electric furnace heat treatment of soil and sludge: the method of Bu 'in which the aforementioned exhaust gas treatment equipment to remove impurities in the exhaust gas can be activated carbon tank, washing tower, absorption tower , Catalyst oxygen, filter bag dust collector, Venturi dust cleaner, electrostatic dust collector, etc., are not prepared to be treated according to the characteristics of pollutants to be adsorbed, removed, absorbed, and oxidized; if an activated carbon tank is used, Calculate the% size of the tank body according to formula (5) — (7): V = mi—⑷ 叩 (c.) (㈣π PaPadA Formula (5) Where V = adsorption bed speed; ma = gas mass flow rate; α, / 5 = balance coefficient between active catalyst and adsorbate; Pa = gas density; pad = radon density of the adsorption bed; A = cross section of the adsorption bed Area; CQ = adsorption saturation concentration; after knowing the velocity of the adsorption bed, the adsorption break through time is equal to: Page 29 553782 6. Scope of patent application L-3 Equation (6) where L is the height of the adsorption bed, (5 is the thickness of the adsorption zone, and 5 is: Equation (7) is about 5-ma β-1 1- (0.09) β1 where κ is the film impedance and the adsorbent Function of effective surface area, between 50 sec—1.