JPH09273735A - Treating method of waste liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the using amount of auxiliary fuel in a waste liquid incinerating furnace by utilizing heat energy, generated in a waste liquid treating facility, effectively, in the treating method of waste liquid in the treatment of wastes, which is equipped with a solid waste incinerating furnace and the waste liquid incinerating furnace. SOLUTION: Waste liquid is treated by a method wherein steam, becoming a heat source for heating indirectly and condensing the waste liquid, is generated by utilizing the heat energy of exhaust gas, generated from a solid waste incinerating furnace, the waste liquid is heated indirectly in an indirectly heating and condensing device 11, employing the steam generated in a boiler by the heat energy of exhaust gas of the solid waste incinerating furnace 3, and is condensed, then, condensed liquid is incinerated in the waste liquid incinerating furnace 13 while waste steam, generated in the waste liquid incinerating furnace 13, is introduced into the solid waste incinerating furnace 3 to treat the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a waste oil containing a high boiling point oil such as rolling oil and machine oil, a waste liquid containing a waste acid, a waste alkali and the like.

[0002]

2. Description of the Related Art Acid for chemical treatment or machining
Alkali, rolling oil, machine oil, etc. are used, and these waste liquids are detoxified and disposed of.

FIG. 2 is a processing flow chart of a conventional waste liquid containing waste acid, waste alkali or waste oil.

In the industrial waste treatment system, the waste liquid treatment system comprises solid waste incineration and waste liquid incineration.

A waste liquid containing waste acid, waste alkali and waste oil is subjected to pH adjustment in a pretreatment facility, separated into waste oil, waste liquid and sludge in a separation tank and stored in a waste liquid tank 1 and a waste oil tank 2.

The sludge separated from the waste liquid and dried is
If necessary, in order to make up for the shortage of heat source, waste plastic is added and put into the solid waste incinerator 3 for incineration. As the solid waste incinerator, for example, a solid waste incinerator 3 including a rotary kiln 3a and a stalker type furnace 3b is used. Exhaust vapor containing an organic substance generated in a waste liquid concentrating furnace 4 to be described later is introduced into the solid waste incinerator 3 to treat the organic substance at a high temperature to decompose it.

Combustion residues that fall to the bottom of the solid waste incinerator 3 are discharged to the water-sealed conveyor 3c and disposed of as incineration ash, and the exhaust gas is detoxified by the exhaust gas treatment facility and then discharged.

The waste oil separated in the pretreatment facility is used as fuel in the waste liquid concentrating furnace 4 and the waste liquid incinerator 8. Heavy oil is added from the heavy oil tank 5 as auxiliary fuel to the waste oil to be introduced into the waste liquid concentrating furnace 4 and burned, and the generated combustion gas is downcomered into a condensing can 6 provided at the bottom of the waste liquid concentrating furnace 4. It is jetted directly into the liquid through 7, and the combustion energy evaporates the water content in the waste liquid in the concentrator to concentrate the waste liquid.

The waste liquid separated in the pretreatment facility is supplied to the concentration canister 6 for incineration in the waste liquid incinerator 8 and concentrated, and then introduced into the waste liquid incinerator 8.

Exhaust vapor containing organic substances contained in the waste liquid generated in the concentrating can 6 is introduced into the solid waste incinerator 3 and decomposed.

Then, the concentrated liquid in the concentrating can 6 is sprayed from the waste liquid spray nozzle of the second waste liquid incinerator 8, and the waste oil separated in the pretreatment facility is introduced together with the heavy oil as the auxiliary fuel and burned at a high temperature. The generated combustion gas is transferred to the cooling recovery can 9 provided at the lower part of the waste liquid incinerator 8 in the downcomer tube 10.
It is cooled by jetting directly into the liquid through, and the recovered liquid is sent to the wastewater treatment facility and the generated exhaust steam is sent to the exhaust gas treatment facility for treatment.

[0012]

In the above waste liquid treatment, since the waste liquid is concentrated and incinerated in the two waste liquid concentrating furnaces and the waste liquid incinerator, the water content in the waste liquid must be raised to a high temperature. Requires an auxiliary fuel, and in the case of waste liquid having a high water content, a large amount of auxiliary fuel is required.

Therefore, in the present invention, in a method for treating waste liquid in waste treatment provided with a solid waste incinerator and a waste liquid incinerator, the thermal energy generated in the solid waste incinerator is effectively used to effectively utilize the waste liquid incinerator. The present invention provides a method for treating waste liquid, which reduces the amount of auxiliary fuel used in the above.

[0014]

DISCLOSURE OF THE INVENTION The present invention treats waste liquid by generating steam, which serves as a heat source for indirectly heating and concentrating waste liquid, by utilizing thermal energy of exhaust gas generated from a solid waste incinerator. Then, the waste liquid is indirectly heated and concentrated by an indirect heating concentrator that uses the steam generated in the boiler by the thermal energy of the exhaust gas of the solid waste incinerator as an indirect heating source, and the generated steam is introduced into the solid waste incinerator. Or treat it with a condenser to cool it, condense it, and after draining it, evaporate the treated water as condenser cooling water,
Disperse exhaust gas from the condenser into the atmosphere. If the concentrate contains a large amount of oil, it can be used as waste oil.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a processing flow chart of waste liquid according to the present invention. The pH of the waste liquid containing waste acid, waste alkali, and waste oil is adjusted by a pretreatment facility, and the waste liquid, waste liquid, and sludge are separated in a separation tank and stored in a waste liquid tank and a waste oil tank.

The sludge separated from the waste liquid and dried is
If necessary, in order to make up for the shortage of heat source, waste plastic is added and put into the solid waste incinerator 3 for incineration. In this embodiment, as the solid waste incinerator 3, a floating combustion furnace is used in which solid waste such as sludge and waste plastic charged from the furnace top floats in the high temperature furnace and burns while reaching the furnace bottom. ,
The burner for raising the temperature of the solid waste incinerator 3 may burn the waste oil obtained in the pretreatment facility, and the combustion air is supplied from the furnace wall to maintain the furnace temperature at 900 to 1000 ° C. Controlled as.

Exhaust vapor containing an organic substance generated in an indirect heating concentrator 11 to be described later is introduced into the solid waste incinerator 3 to treat the organic substance at a high temperature to decompose it.

The combustion residue falling on the bottom of the solid waste incinerator 3 is discharged to the water-sealed conveyor 3c and disposed of as incinerated ash.

Exhaust gas from the solid waste incinerator 3 is sent to a downstream boiler, and the boiler 12 is heated by the heat energy of the exhaust gas.
The steam generated in step 1 is used as an indirect heating source of the indirect heating concentrating device 11.

Although a floating combustion furnace is used as the solid waste incinerator 3 in this embodiment, a solid waste incinerator comprising a rotary kiln and a stalker type furnace may be used as in the conventional example.

The waste liquid is concentrated by the indirect heating concentrator 11. The indirect heating concentrator 11 indirectly heats and condenses the waste liquid using the steam generated in the boiler 12. When the exhaust vapor generated from the indirect heating concentrator 11 contains an organic substance, it is introduced into the solid waste incinerator 3, and the organic substance is treated at a high temperature to be decomposed.

When there is no low boiling point organic substance in the waste liquid and no oil is produced by the indirect heating, the steam generated from the indirect heating device 11 is guided to the condenser 16 to be condensed and purified.
It can also be used as cooling water for the condenser 16 after purification treatment in 7. The exhaust gas from the condenser 16 diffuses into the atmosphere.

When the waste liquid contains a large amount of high boiling point oil, after being concentrated by the indirect heating concentrator 11,
It can be used as waste oil as a fuel source.

The heating steam discharged from the indirect heating concentrator 11 is cooled and returned to the boiler 12, heated by the boiler to be steam, and circulated to the indirect heating concentrator 11 again.

The concentrated waste liquid concentrated by the indirect heating concentrator 11 is sent to the waste liquid incinerator 13, the waste liquid is sprayed from the waste liquid spray nozzle and burned at a high temperature, and the generated combustion gas is provided in the lower part of the waste liquid incinerator 13. The cooling and collecting can 14 is sprayed directly into the liquid through the downcomer tube 15 for cooling,
The recovered liquid is treated as waste water, and the generated steam is treated as exhaust gas.

[0026]

EXAMPLE A waste liquid at 20 ° C. having a salt concentration of 4 to 5%, a high boiling point oil content of 2 to 5%, and the balance of water is sent to an indirect heating concentrator. Indirect heating concentrator generated in boiler 15
The waste liquid is indirectly heated by steam at 0 to 180 ° C,
Concentrate 5 times.

Exhaust vapor at 80 to 90 ° C. containing organic substances generated in the indirect heating concentrator is introduced into a solid waste incinerator, and the organic substances are subjected to high temperature treatment to be decomposed.

800 to 10 generated in a solid waste incinerator
Exhaust gas at 00 ° C is sent to the boiler to generate heating steam to be sent to the indirect heating concentrator, and 300 to 500 ° C is generated.
It is discharged from the boiler at and is treated as exhaust gas.

The concentrated liquid of the indirect heating concentrator at 80 to 90 ° C. is sent to the waste liquid incinerator, and the temperature inside the furnace is 800 to 1000.
Incinerate at ° C. Auxiliary fuel is added according to the calorific value. The recovered liquid is treated as waste water, and the generated steam is treated as exhaust gas.

[0030]

EFFECT OF THE INVENTION An indirect heating concentrator for indirectly heating with steam is provided between the solid waste incinerator and the waste liquid incinerator, and the steam serving as a heat source for indirect heating is supplied with heat energy of exhaust gas generated from the solid waste incinerator. Since it is effectively used, the amount of auxiliary fuel used can be reduced to 1/3 to 1/5 or less of the conventional amount.

[Brief description of drawings]

FIG. 1 is a process flow diagram of waste liquid according to the present invention.

FIG. 2 is a processing flow diagram of a conventional waste liquid.

[Explanation of symbols]

 1 waste liquid tank 2 waste oil tank 3 solid waste incinerator 3a rotary kiln 3b stoker furnace 3c water-sealed conveyor 4 waste liquid concentrator 5 heavy oil tank 6 concentrator 7 downcomer tube 8 waste liquid incinerator 9 cooling recovery can 10 downcomer tube 11 Indirect heating concentrator 12 Boiler 13 Waste liquid incinerator 14 Cooling recovery can 15 Downcomer tube 16 Condenser 17 Purifier

Claims (2)

[Claims] 1. A waste liquid is indirectly heated and concentrated by an indirect heating concentrator that uses steam generated by a boiler by thermal energy of exhaust gas from a solid waste incinerator as an indirect heating source, and the concentrated liquid is incinerated in a waste liquid incinerator. Then, the waste liquid generated in the waste liquid incinerator is introduced into the solid waste incinerator for processing, and the waste liquid is treated. 2. A waste liquid is indirectly heated and concentrated by an indirect heating concentrator that uses steam generated in a boiler by thermal energy of exhaust gas from a solid waste incinerator as an indirect heating source, and the concentrated liquid is incinerated in a waste liquid incinerator. However, the exhaust steam generated in the waste liquid incinerator is condensed in a condenser, after the condensate is purified, the treated water is evaporated as cooling water for the condenser, and the exhaust gas from the condenser is released to the atmosphere. Waste liquid treatment method.