JP4535982B2 - Method and apparatus for treating oil-containing waste liquid - Google Patents

Description

  The present invention is a treatment method that enables reuse as a fuel by removing moisture from an oil-containing waste liquid, and obtains a heat source for removing water from the oil-containing waste liquid using the obtained fuel. It relates to the device.

  In recent years, environmental issues have attracted particular attention, and in particular, measures to prevent pollution of rivers and seawater have become issues. As a cause of polluting rivers and seawater, it is regarded as a problem that oil-containing waste liquid flows out into sewage as it is in addition to general domestic wastewater. This oil-containing waste liquid is a waste liquid containing oil and moisture generated during frying dregs and seasoning oil in a food processing factory, a process of removing oil from foods, and the like. In addition to food processing factories, it is also included in wastewater from ships and the like. Generally, oil-containing waste liquid is required to be detoxified as industrial waste.

  Furthermore, regulations on industrial waste discharged from each company are becoming stricter, and there is a demand for the establishment of a zero emission factory by increasing the processing capacity within the company. There is no problem with industrial waste that is easy to process and reusable, but it is difficult to process a large amount of waste liquid containing oil and moisture, and there is no means for easy processing even if an industrial waste processor takes it. Is the actual situation.

  As a result of analysis by the inventors of the seasoning oil generated in the food processing factory and the oil-containing waste liquid generated during the oil removal process, there are 291 g of water, 270 g of contained vegetable oil, and 378.6 g of solid residue in 1 liter of the waste liquid. In terms of the ratio, water: contained vegetable oil: solid residue = 31%: 29%: 40%. In addition, the composition of the vegetable oil and solid residue excluding moisture is 0.4% for protein, 63.7% for lipid, 4.8% for carbohydrate, and 0.1% for ash (all by weight). It is.

  FIG. 2 is a result of measuring and comparing the calorific values of distilled oil, residue, and oil-containing waste liquid, 38,340 J / g (joule / g) of distilled oil, 31,522 J / g of residue, 23, It was 709 J / g.

With respect to the above, Patent Document 1 aims to combust waste oil without draining it outside by evaporating and burning waste oil containing a large amount of water by completely closing the heating, evaporation and combustion processes. A burner using waste oil as fuel is provided at the center of the end face of the cylindrical combustion furnace, an oil-impregnated steam heater is provided at the center of the ceiling of the combustion furnace, and a funnel-shaped hot air passage is provided on the lower side wall of the combustion furnace. And connecting the heat exchanger of the evaporator, and connecting the exhaust path to the opposite side of the hot air path of the heat exchanger, and connecting the evaporator of the evaporator above the heat exchanger, A waste oil combustion treatment apparatus is disclosed in which an upper opening of an evaporator is connected to an oil-containing steam heater of a combustion furnace by an oil-containing steam conduit to form a completely closed combustion path.
JP 7-71737 A

  If oil-containing waste liquid can be combusted, it is effective as a measure to prevent pollution of rivers and seawater. However, it is impossible to completely burn oil-containing waste liquid containing a large amount of water as it is. When treated, there is a problem that odors and oily smoke are generated to cause secondary pollution, and a large amount of treatment costs are required. Further, as can be seen from the data shown in FIG. 2, the heat generation amount of the oil-containing waste liquid is about 23,000 J / g, and the heat generation amount necessary for combustion is insufficient. Furthermore, it takes one week after storage to separate the oil-containing waste liquid into three layers: water, oil, and residue. In addition, oil cannot be burned as it is, and there are lipids in the residue. There is a problem that the economic effect of reducing the amount of waste liquid is small due to the amount of separated water and residue.

  Therefore, in view of the above-mentioned conventional problems, the present invention makes an oil-containing waste liquid containing frying residue, oil, and moisture into a combustible state by heat treatment, and is used as fuel for a boiler and burned in the boiler. By reusing the steam obtained as a heating source for oil-containing waste liquid and effectively using the surplus steam for other applications, it is possible to effectively use the amount of heat contained in the oil-containing waste liquid and to treat conventional oil-containing waste liquid. The purpose is to reduce the processing cost required for the process.

  In order to achieve the above-mentioned object, the present invention flows oil-containing waste liquid containing oil and water into an oil-containing waste liquid evaporation tank and heats it to evaporate the water to produce distilled oil. Is cooled by flowing into the distilled oil cooling tank through a strainer, the viscosity of the distilled oil is reduced to a suitable level as a fuel by a fuel reformer, and the obtained fuel is burned by an oil burner. The boiler in which the heat exchanger is incorporated is operated, and the steam obtained by the heat exchanger is introduced into the oil-containing waste liquid evaporation tank and used as a heating source for the oil-containing waste liquid, and the steam is used for other purposes. The basic method is an oil-containing waste liquid treatment method and apparatus which are also used for the above.

  The heating temperature of the oil-containing waste liquid in the oil-containing waste liquid evaporation tank is 135 ° C. to 145 ° C., and the ratio of distilled oil to water in the fuel reformer is 7: 3. As the oil burner, a special diffusion spray burner suitable for burning waste oil fuel is used.

  According to the method and apparatus for treating an oil-containing waste liquid according to the present invention, a distillation oil is produced by heating an oil-containing waste liquid containing oil and water such as frying residue in an oil-containing waste liquid evaporation tank. After removing the solid residue in the oil, it is cooled and further emulsified into a state suitable as fuel by lowering the viscosity with a fuel reformer, so that it can be burned with an oil burner as fuel and incorporated in the boiler Steam is obtained by a heat exchanger, and this steam is introduced into an oil-containing waste liquid evaporation tank and reused as a heat source for the oil-containing waste liquid, and the steam can be used for other purposes. There is no risk of causing secondary pollution due to odor and smoke when burning the above distilled oil, and special treatment as industrial waste is achieved by reusing steam obtained by boiler operation as a heating source for oil-containing waste liquid This is effective as a measure to prevent pollution of rivers and seawater.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an oil-containing waste liquid treatment method and apparatus according to the present invention are described below with reference to the drawings. FIG. 1 is a schematic diagram showing an overall treatment apparatus for oil-containing waste liquid to which the present invention is applied. First, main components will be described. 1 is an oil-containing waste liquid separation tank, 2 is an oil-containing waste liquid stock tank, 3 Is a fluid pump, 4 is an oil-containing waste liquid evaporation tank, 5 and 6 are distilled oil cooling tanks, 7 and 8 are strainers, 9 is a fluid pump, 10 is a fuel reformer, 11 is a fluid pump, 12 is an oil burner, 13 Is a compressor, 14 is a boiler, and 15 is a steam header.

  According to such an oil-containing waste liquid treatment apparatus, an oil-containing waste liquid containing oil and water such as frying residue is first put into the oil-containing waste liquid separation tank 1 and left to stand for a predetermined time so that the oil-containing waste liquid and moisture First, only water as a supernatant liquid is removed, and then the valve 20 is opened, and the oil-containing waste liquid to be treated flows into the oil-containing waste liquid stock tank 2 and is temporarily stored. Next, the valve 21 is opened, and the fluid pump 3 is driven to cause the oil-containing waste liquid to flow into the oil-containing waste liquid evaporation tank 4.

  The oil-containing waste liquid is heated while being stirred by the electric motor 22 and the stirring blade 23 attached to the oil-containing waste liquid evaporating tank 4, thereby evaporating the water in the oil-containing waste liquid to produce distilled oil and in the oil-containing waste liquid. The moisture contained in the steam is changed, and the moisture of the steam used as a heating source is discharged from the drain 24. When the temperature of the oil-containing waste liquid exceeds 100 ° C., the removal of water is almost completed, and at the same time, the protein in the oil-containing waste liquid is also heated, so that combustion becomes easy along with carbonization along with volume reduction. As a heating source for the oil-containing waste liquid in the oil-containing waste liquid evaporation tank 4, high-temperature steam led from the steam header 15 through the pipe 25 is used as will be described in detail later, and the temperature in the oil-containing waste liquid evaporation tank 4 Reaches 135 ° C to 145 ° C.

  Next, the valves 26, 27 and 28 are opened, and the distilled oil obtained by the above heat treatment flows into the distilled oil cooling tanks 5 and 6 through the strainers 7 and 8, and is cooled. The strainers 7 and 8 are installed to remove solid residues contained in the distilled oil, and only the distilled oil is removed from the distilled oil cooling tank 5 by straining the residue in the distilled oil using a filter material of about 80 mesh. , 6 to flow into. At this time, the distilled oil 50 and the residue are 10 with respect to the oil-containing waste liquid 100 in volume ratio. In addition, when it is not necessary to use the distilling oil cooling tanks 5 and 6 simultaneously, you may use alternately one tank at a time.

  Next, by opening the valves 29 and 30 and driving the fluid pump 9, the distilled oil cooled in the distilled oil cooling tanks 5 and 6 is caused to flow into the fuel reformer 10. The fuel reformer 10 aims to lower the viscosity of the obtained distilled oil and reform it into a state suitable for use as fuel. Specifically, the fuel reformer 10 contains the distilled oil in the fuel reformer 10. At the same time, an appropriate amount of water is added from the water inlet 31 and stirred to emulsify the distilled oil. A suitable ratio of distilled oil to water is about 7: 3. There are also cases where other auxiliary materials required as fuel are added as necessary.

  The fuel obtained by the fuel reforming device 10 is sent to the oil burner 12 by driving the fluid pump 11, and the fuel is burned together with the combustion action by the air sent from the compressor 13, so that the boiler 14 It becomes an operation state. As the oil burner 12, a special diffusion spray burner suitable for burning waste oil fuel is used. A spiral heat exchanger 33 is incorporated in the boiler 14, and water supplied from the water inlet 34 is heat-exchanged when flowing through the heat exchanger 33 to be converted into high-temperature steam. It flows into the header 15.

  The steam header 15 has a function of distributing steam, and the steam obtained as described above by opening the valve 35 is led from the steam header 15 into the oil-containing waste liquid evaporation tank 4 through the pipe 25. It is used as a heating source for oil-containing waste liquid. Further, when the valve 36 is opened, the steam is used for other purposes, for example, for the purification and sterilization of the waste water by being led to the waste water treatment reactor 37.

  According to the experiments by the present inventors, the oil temperature of the distilled oil in the oil-containing waste liquid evaporation tank 4 necessary for converting the oil-containing waste liquid into fuel is required to be 140 ° C. at the minimum, and The pressure of the boiler 14 at the time of combustion needs to be 0.6 MPa (saturation temperature 164 ° C.) or more. The temperature of the steam obtained by the operation of the boiler 14 can be controlled by the pressure of the boiler 14, and the heating temperature can be accurately controlled below the smoke point of distilled oil. Appropriate control of the heating temperature can avoid the risk of equipment fouling by oily smoke and the occurrence of fire due to high-temperature heating.

  FIG. 3 is a graph showing the results of the first and second measurements of the oily waste liquid during the distillation, measuring the change in weight% of the carbon content of the residue in the oil at 140 ° C. for an elapsed time of 30 minutes twice. Yes, the carbonization degree of carbon peaks when the elapsed time is 20 minutes in both cases.

  The necessity of the fuel reformer 10 will be described below. Usually, the static viscosity of distilled oil is 0.1 Pa · a at 20 ° C., and it is difficult to spray and burn using a general oil burner. In order to bring this static viscosity to a range that can be combusted at room temperature, it is necessary to add water to make a low-viscosity emulsion. As described above, the static viscosity of fuel with a ratio of distilled oil to water of 7: 3 can be lowered to 0.05 Pa · a, and smoke can be suppressed by burning it as an emulsion fuel. .

  Further, when a special diffusion spray burner is used as the oil burner 12, the mesh for the distilled oil by the strainers 7 and 8 is 80 mesh which is a coarser mesh than the mesh 150 to 200 which is a mesh for the fuel oil of a normal burner. Because it is good, it is possible to reduce the time required for tanning.

  As described above in detail, according to the present invention, a heat exchanger incorporated in a boiler is obtained by emulsifying a distilled oil produced by heat-treating an oil-containing waste liquid by a fuel reformer and then combusting with an oil burner. Since the steam obtained in step 1 can be introduced into the oil-containing waste liquid evaporation tank and reused as a heating source for the oil-containing waste liquid, the steam can be used for other purposes, eliminating the need for special treatment as industrial waste. Since the processing cost is reduced and effective as a countermeasure to prevent pollution of rivers and seawater, frying and seasoning oil in food factories, oil-containing waste liquid containing oil and moisture generated during the oil draining process of food, It can be widely used for the treatment of oil-containing waste liquid contained in wastewater from ships and the like.

The schematic diagram which shows the processing apparatus of the oil-containing waste liquid to which this invention is applied generally. The graph which shows the result of measuring and comparing the calorific value of distilled oil, residue, and oil-containing waste liquid. The graph which shows the change of the carbon content of the residue in distilled oil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Oil-containing waste liquid separation tank 2 ... Oil-containing waste liquid stock tank 3, 9, 11 ... Fluid pump 4 ... Oil-containing waste liquid evaporation tank 5, 6 ... Distilled oil cooling tank 7, 8 ... Strainer 10 ... Fuel reformer 12 ... Oil burner 13 ... Compressor 14 ... Boiler 15 ... Steam header 22 ... Electric motor 23 ... Stirrer blades 31, 34 ... Water inlet 33 ... Heat exchanger 37 ... Waste water treatment reactor

Claims (7)

  The oil-containing waste liquid containing oil and moisture flows into the oil-containing waste liquid evaporation tank and is heated to evaporate the water to produce distilled oil, and this distilled oil is passed through the strainer into the distilled oil cooling tank. A boiler with a built-in heat exchanger is prepared by injecting and cooling the distilled oil, emulsifying the distilled oil into a state suitable for fuel by reducing the viscosity with a fuel reformer, and burning the obtained fuel with an oil burner. The oil-impregnated, characterized in that the steam obtained by the heat exchanger is introduced into the oil-containing waste liquid evaporation tank and used as a heating source for the oil-containing waste liquid, and the steam is also used for other purposes Waste liquid treatment method.   Oil-containing waste liquid containing oil and water is put into the oil-containing waste liquid separation tank and left standing for a certain period of time to roughly classify oil-containing waste liquid and water, and the oil-containing waste liquid to be treated is stored in the oil-containing waste liquid stock tank. It flows into the water and temporarily stores it, then flows into the oil-containing waste liquid evaporation tank, and heats the oil-containing waste liquid in the oil-containing waste liquid evaporation tank while stirring, thereby evaporating water and producing distilled oil. In addition, the protein contained in the oil-containing waste liquid is changed, this distilled oil is cooled by flowing into the distilled oil cooling tank through the strainer, and the distilled oil is allowed to flow into the fuel reformer. Of water to reduce the viscosity of the distilled oil and emulsify it into a state suitable for use as a fuel.The resulting fuel is burned with an oil burner to create a boiler with a built-in heat exchanger. To the heat exchanger The steam obtained in this way is introduced into the oil-containing waste liquid evaporation tank from the steam header and used as a heating source for the oil-containing waste liquid, and the steam is also used for other purposes. Method.   The method for treating an oil-containing waste liquid according to claim 1 or 2, wherein the heating temperature of the oil-containing waste liquid in the oil-containing waste liquid evaporation tank is 135 ° C to 145 ° C.   The method for treating an oil-containing waste liquid according to claim 1 or 2, wherein a ratio of distilled oil to water in the fuel reformer is 7: 3.   Oil-containing waste liquid evaporation tank that generates heated oil by charging oil-containing waste liquid containing oil and water, distilled oil cooling tank with strainer that cools distilled oil, and suitable for fuel by reducing the viscosity of distilled oil A fuel reformer that emulsifies the oil into a heated state, an oil burner that burns the obtained fuel, a boiler that is operated by the oil burner, and a heat exchanger that is built into the boiler and generates high-temperature steam. The steam obtained by the heat exchanger is introduced into an oil-containing waste liquid evaporation tank and used as a heat source for the oil-containing waste liquid, and the steam is also used for other purposes. Oily waste liquid treatment equipment.   Oil-containing waste liquid containing oil and water and letting it stand for a certain period of time, oil-containing waste liquid separation tank that divides oil-containing waste liquid and water roughly, and oil-containing waste liquid that temporarily stores oil-containing waste liquid to be treated A stock tank, an oil-containing waste liquid evaporating tank that produces distilled oil by charging the oil-containing waste liquid in the oil-containing waste liquid stock tank and heating it with stirring, and a strainer that removes solid residue in the distilled oil A distillation oil cooling tank that cools the distilled oil, a fuel reformer that lowers the viscosity of the distilled oil and emulsifies it into a state suitable as a fuel, an oil burner that burns the obtained fuel, and the oil burner And a heat exchanger that is built into the boiler and generates high-temperature steam, and the steam obtained by the heat exchanger is introduced into the oil-containing waste liquid evaporation tank to provide oil-impregnating properties. Waste liquid heating As well as use as a processing unit of the oil-containing wastewater, characterized in that also utilizes the gas the evaporated for other applications.   The apparatus for treating oil-containing waste liquid according to claim 5 or 6, wherein a special diffusion spray burner suitable for burning waste oil fuel is used as the oil burner.

Images