JPH08257599A - Treatment of muddy waste, device therefor and method for using treated product - Google Patents

Abstract

PURPOSE: To effectively separate a gasification component and a dried solid component from muddy waste by bringing muddy waste into contact with combustion gas after complete combustion and separating muddy waste into the gasification component and the powdery dried solid component and thereafter exhausting the gasification component and recovering the dried solid component. CONSTITUTION: Muddy waste is led to a raw material tank 2 and introduced into a raw material supply hopper 3 through a route 14 and carried into the housing 6 of a drying part of a screw conveyor 4. In a jet treatment part (a), muddy waste is instantaneously dried and disintegrated by a high-temperature and high-pressure jet spout supplied from a jet burner 5. On one side, both a gasification component and a dried-disintegrated powdery solid component which are produced from muddy waste are passed to a gravity setting machine 7 through a conduit 15. The powdery dried solid component is collected in the recovery part 9 of the solid component through a separated powder-receiving vessel 8. Furthermore, the gasification component is introduced into a cyclone 10 through a conduit 16 and thereafter exhausted through a conduit 17 and passed through a deodorizing device 13 from the low part.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method and an apparatus for treating mud waste and a method for using the treated product. More specifically, the present invention provides a method for efficiently treating mud-like wastes such as sewage sludge and various wastewater sludges to convert them into solid components having a low water content, an apparatus for use in the method, and the above treated products. The present invention relates to a method of using a solid component as a fuel or the like.

[0002]

2. Description of the Related Art At present, since aqueous waste such as sewage usually contains a large amount of water, its treatment must first be performed by contact with a wastewater treatment agent or activated sludge, sedimentation concentration, mechanical dehydration (for example, filtration). It is carried out by performing various operations such as dehydration, centrifugal dehydration) or heat dehydration (e.g. evaporation, drying) and the like to obtain dehydrated sludge (dehydrated cake) having a water content of 70 to 90% at the final stage. After that, the dehydrated sludge is incinerated,
Is it used for landfill or land reclamation as it is,
Or it was dumped in a river or ocean.

However, due to the influence of the polymer flocculant added in the dehydration treatment step and the waste water treatment agent such as ferric chloride,
There is a problem that bacteria in soil or sea do not act on sludge used for land and sea land reclamation, and corrosion by bacteria does not progress, and dumping into public waters such as rivers and seas causes environmental pollution. It is caused by the law and regulated by various laws, and it is impossible or will be impossible in the near future. Therefore, the only remaining method is to incinerate, but for this purpose a special incinerator must be constructed, and the dehydrated cake that is the material to be incinerated still needs a large amount of fuel because it has a high water content. Not only has the problem of treating a large amount of ash remaining after incineration not been solved.

[0004]

Therefore, as the necessity of environmental protection is strongly recognized, there is a demand for efficient treatment of a large amount of aqueous waste discharged every day and effective use of the treated products. Very high. The present invention has been made in consideration of such a situation, and is smokeless, odorless, in a short time, and at low cost without burning muddy waste derived from sewage or various wastewaters. An object of the present invention is to provide a method and an apparatus for effectively separating a vaporized component and a dry solid component from the muddy waste, and a method for using the dry solid component.

[0005]

[Means for Solving the Problems] That is, in the method for treating mud-like waste of the present invention, (a) the mud-like waste is brought into contact with combustion gas at 1000 to 2000 ° C. after complete combustion, The waste is made into a vaporized component and a powdery dry solid component, and (b) the vaporized component and the dry solid component are separated, the vaporized component is discharged, and the dry solid component is recovered. To do.

The term "mud waste" as used in the present invention means sludge or sludge obtained by preliminarily dehydrating aqueous waste such as sewage, night soil, domestic wastewater or industrial wastewater to a certain extent, and its water content is Although it depends on the type of the original aqueous waste, it is usually 70 to 90% and is also called dehydrated cake or the like. Preliminary dehydration of the aqueous waste is carried out according to a conventional method, after the colloidal particles in the aqueous waste are condensed and aggregated with a wastewater treatment agent to form flocs, and then sedimentation concentration or mechanical dehydration such as filtration dehydration, Centrifugal dehydration, etc.
Further, if necessary, dehydration by heat, such as evaporation and drying, is performed. The wastewater treatment agent includes a flocculant such as aluminum sulfate (commonly known as sulfuric acid band), polyaluminum chloride (commonly known as pack), ferric sulfate, ferrous sulfide, ferric chloride and chlorinated copper powder. Agents, organic flocculants such as nonionic, cationic or anionic polyacrylamide polymer flocculants; neutralizing agents;
For example, acids such as sulfuric acid and hydrochloric acid, or bases such as calcium hydroxide (slaked lime) and sodium hydroxide (caustic soda); and oxidizing agents such as chlorine and coconut powder, or reducing agents such as ferrous sulfate and sodium sulfite. There is.

Further, in the present invention, the combustion gas for vaporizing the muddy waste is 1000 after the complete combustion as described above.
It is not particularly limited as long as it has a temperature of up to 2000 ° C., it is after complete combustion, and since oxygen hardly exists, mud-like waste does not burn. The combustion gas includes, for example, high-temperature and high-pressure combustion gas generated by completely combusting compressed air or a mixed gas of high-pressure oxygen and high-pressure kerosene (or gasoline, heavy oil, natural gas, etc.) in the combustion chamber of a jet burner. . The combustion gas can be vaporized with higher efficiency by contacting with the muddy waste as a jet jet from the nozzle. The temperature of the combustion gas is appropriately selected according to the type of the muddy waste to be treated together with the pressure and the speed thereof.
0 to 1500 ° C, particularly 1200 to 1300 ° C is preferable. Further, it is preferable that the combustion gas has a high speed, for example, Mach 2 to 7 because the efficiency of drying and crushing the muddy waste is improved.

In the method for treating mud-like waste of the present invention, after the mud-like waste is changed into the vaporized component and the solid component in the step (a), the vaporized component and the solid component are separated in the step (b). Although it is separated, this separation can usually be performed in one step or multiple steps by a physical method. For example, a gravity settler or classifier is used to physically separate and collect larger solids, and then a cyclone that uses centrifugal force is used to separate and collect smaller solids. It can be done in two stages. Further, depending on the solid content of the mud-like waste that is the object to be treated, it may consist of three or more steps, and the solids may be finely separated or may be carried out in only one step. However, since the dry solid component obtained in step (a) of the treatment method of the present invention has already become particles (powder) having a relatively uniform particle size, physical separation in only one step is sufficient. is there. In the separation of the solid component in the separation step (b), the step (a)
It is important to discharge the vaporized component generated in step 1 without liquefying it. Therefore, after the treatment in the step (a), the vaporized component is 100 to 300 during the step (b).
It should be maintained in the temperature range of ° C, preferably 120 to 250 ° C.

The discharge of the vaporized components in the step (b) of the method for treating sludge-like waste according to the present invention may be released into the atmosphere as it is, but since the substance to be treated often has a bad odor, the deodorizing device For example, it is preferably discharged after passing through a spray tower, a packed tower, a cascade tower, a cross flow liquid gas contact absorption device, etc. adopting, for example, an ozone oxidation method, an activated carbon adsorption method or a catalytic combustion method. Further, the vaporized component in this step (b) may be passed through a condenser to liquefy the water, whereby the water can be reused.

The present invention also includes 1000-2 after complete combustion.
A drying unit for converting the muddy waste into a vaporized component and a powdery dry solid component by contacting with a combustion gas at 000 ° C., and a separation unit connected to the dry unit for separating the vaporized component and the dry solid component Part, the dry solid component from the separation part is introduced,
The present invention relates to an apparatus for treating mud-like waste, which comprises a solid component recovery unit for recovery and a vaporized component discharge unit for introducing and discharging the vaporized component from the separation unit.

In the above treatment apparatus of the present invention, as in the case of the treatment method, it is sufficient for the separation section to have one physical separator such as a gravity settler or a cyclone, but the drying section. Depending on the state of the dry solid components in, a gravity settler for separating relatively large solids and a cyclone for separating smaller solids may be provided. It may be provided individually, or may be further provided with another separator such as a classifier or a bag filter. Further, the processing apparatus is provided with a solid component recovery unit and a vaporized component discharge unit for introducing, recovering, or discharging the dry solid component and the vaporized component from the separating unit, respectively. The vaporized component discharge part may further be provided with a deodorizing device and a condenser for liquefaction.

The dry solid component separated and recovered in the step (b) of the method for treating sludge-like waste according to the present invention is a powdery particle having a uniform particle size as described above, which may be treated as it is or further. It can be used as fuel, soil conditioner or building material. Therefore, the present invention relates to a powdery dry solid component obtained by the method for treating mud waste of the present invention.

The muddy waste treated in the present invention has a relatively high calorie content, and in many cases, a polymer flocculant is added in the step of pre-dewatering aqueous waste, which is directly treated as muddy waste. It is particularly high in calories because it remains in the food. Therefore, the powdery dry solid component obtained by drying such a muddy waste without burning is also high in calories and is particularly useful as a fuel. For example, a fuel in which a finely pulverized coal and a heavy oil mixed fuel (COM) is partially or entirely replaced with the powdery dry solid component of the present invention can be used. Therefore, the present invention further relates to a fuel containing a powdery dry solid component obtained by the method for treating mud-like waste of the present invention.

The ash remaining after burning the powdery dry solid component of the present invention is an inorganic ash, which can be mixed with, for example, limestone to obtain high quality cement. Therefore, the present invention also relates to a cement containing ash remaining after burning the powdery dry solid component of the present invention.
As the cement of the present invention, self-hardening cement, such as Portland cement, alumina cement, expanded cement, acid phosphate cement or burnt gypsum, latent hydraulic cement, such as lime slag cement, blast furnace cement, high sulfate slag cement or Keens Cement,
Alternatively, mixed cement, for example, lime silicate mixed cement, etc. may be mentioned. Such cement is used for construction, painting, joining materials in civil engineering and construction, or other cement products (plates, tubulars, kawara, Block,
Widely used as containers. Further, the cement of the present invention is produced by crushing raw materials, filtering and firing them, as in the case of ordinary cement. On this occasion,
The ash content after combustion of the dry solid component of the present invention used as the inorganic ash component is already fine particles and has been calcined, so that it can be directly used as a cement component without any treatment. It has been confirmed that the cement of the present invention can obtain high quality cement even if the ash content remaining after burning the powdery dry solid component of the present invention is mixed up to about 30% by weight.

[0015]

As described above, according to the present invention, the aqueous waste or the mud-like waste that has been conventionally dumped on land or at the sea, or has been incinerated / disposed at high cost is burned. Without drying, it can be crushed and recovered as a powdery solid component with a uniform particle size, and the solid component can be reused as fuel, and the ash content after combustion of the solid component used as fuel is the inorganic matter of cement. It can be used as ash. For this reason, the incinerated ash does not pose a problem to the muddy waste treated according to the present invention, and it is completely utilized without any waste. Further, in the present invention, a high-calorie powdery solid component is recovered from the mud-like waste and used as a fuel for burning cement, and after burning a raw material for cement such as limestone, the calcined limestone is Since it is possible to mix with the ash content after combustion of the fuel to produce cement, the treatment of mud waste and the production of cement can be performed by a series of operations.

[0016]

Embodiments of the present invention will now be described with reference to the accompanying drawings, but the present invention is not limited thereto. FIG. 1 schematically shows an embodiment of the muddy waste treatment device according to the present invention. First, the flow of the treatment of the muddy waste by the treatment apparatus 1 will be described, and then the treatment result of the muddy waste (sewage sludge) performed by using this apparatus, and further the dry solid component obtained by the above-mentioned apparatus. The use will be specifically described.

A. Treatment of mud-like waste by treatment equipment Water content of sewage, human waste, domestic wastewater or industrial wastewater to be treated by preliminary dehydration 70 to 9
0% of muddy waste is introduced into the raw material tank 2 and then introduced into the raw material supply hopper 3 through a path 14 such as a conduit.
The introduction of the muddy waste from the raw material tank 2 into the hopper 3 may be performed by simply dropping it. The muddy waste is carried into the housing 6 of the drying section by the screw conveyor 4 provided under the raw material supply hopper 3,
In the jet treatment section a therein, high temperature and high pressure (about 1300 ° C., 6 to 7 kg / cm ² , 120 from the tip nozzle of the jet burner 5 entering from the upper part of the housing 6).
(0 m / sec), it is dried and crushed in an instant.

The high-temperature and high-pressure jet jet flow is generated by completely burning the atomized mixed gas of compressed air and high-pressure kerosene in the combustion chamber inside the jet burner 5, and is jetted from the tip nozzle. is there. Compressed oxygen may be used instead of compressed air, and gasoline, heavy oil, natural gas or the like may be used as fuel instead of kerosene. By adjusting the reaction conditions in the combustion chamber, the temperature, pressure and velocity of the jet jet flow are, for example, 1000 to 2000 ° C. and 5 to 20 kg / c, respectively.
It can be appropriately changed within the range of m ² and 500 to 2000 m / sec. Regardless of which condition is adopted, it is necessary to completely burn the fuel. Therefore, oxygen hardly exists in the jet jet flow, and the object to be treated does not burn in the jet treatment section a. As the jet burner 5, for example, the one disclosed in JP-A-55-99527 can be used, but it is not particularly limited as long as it produces a combustion gas satisfying the above conditions.

Next, the vaporized component generated from the muddy waste by contact with the jet burner and the powdery solid component dried and crushed are gravitationally settled through a conduit 15 provided in the upper part of the housing 6. Pass through 7. The conduit 15 and the gravity settler 7 are maintained at 125 to 250 ° C., and the powdery dry solid component from the muddy waste is collected in the solid component recovery unit 9 via the separated powder receiver 8. On the other hand, the vaporized component enters the cyclone 10 via the conduit 16 extending from the upper part of the gravity settler 7. The conduit 16 and the cyclone 10 are also 125-250 ° C.
If there is a finer dry solid component that has been retained by the gravity settler 7 and could not be removed in the gravity settler 7, it is separated by centrifugal force, and the solid component recovery unit 1 is separated via the separated powder receiver 11.
Accumulate to 2. The gravity settler 7 and the cyclone 10 form a separation unit. Here, if the solid component is separated and removed by the gravity settler 7, it is not necessary to provide a cyclone.

The vaporized component is further discharged through a conduit 17 extending from the upper portion of the cyclone 10, passed through a deodorizing device 13 filled with a deodorizing agent such as activated carbon from below, and from a conduit 18 extending from above the deodorizing device 13. The deodorized vaporized component is discharged out of the system through a suction blower (not shown). Here, the conduits 17 and 18 and the deodorizing device 1
3 is also held at 125-250 ° C. Further, before passing the vaporized component from the cyclone 10 through the deodorizing device 13, a finer solid component may be removed by further passing through a bag filter or the like, and the vaporized component discharged from the deodorizing device 13 may be passed through a condenser to remove moisture. Only the vaporized component after the liquefying may be discharged to the outside of the system.

B. Treatment result of mud-like waste by the treatment device The mud-like waste treatment device 1 shown in Fig. 1 was used to actually treat the mud-like waste. The operating conditions and results are shown below. After adding a wastewater treatment agent such as polyacrylamide polymer flocculant or ferric chloride to the sewage, it is preliminarily dehydrated to about 80% by weight of water content by filtration and dehydration to obtain sewage sludge (mud waste). To do. This sewage sludge is sent to the jet treatment section in the drying section at an appropriate supply rate. On the other hand, the jet jet from the jet burner causes kerosene (C / H
₂ ratio = 5.25) and 47.5 kg of air, respectively
/ Hour and a feed rate of 717.1 kg / hour, and auto ignition is generated. The temperature, pressure, and velocity of this jet jet at the time of jetting from the nozzle are 1300 each.
C., 6-7 kg / cm ² and 1200 m / sec.

The sewage sludge dried and vaporized in the jet treatment section is passed through a separation section (a gravity settler and a cyclone held at 150 ° C.), and a dry solid component is collected in a recovery section provided below each of the separation sections. Are collected, and the vaporized components are discharged after passing through a deodorizing device and a suction blower (both kept at 150 ° C.). Most of the dry solid components are recovered in the recovery unit below the gravity settler, their water content is more than 10% by weight, odorless, and their particle size is almost uniform, and they are used as a substitute for COM coal. There was no problem in doing so. It has been confirmed that the water content after treatment can be reduced to only a few wt% by selecting treatment conditions such as reducing the supply rate of sewage sludge to the drying section.

C. Use of dry solid component When the dry solid component from the sewage sludge obtained in the previous section B was mixed with heavy oil to form COM, which was used as a fuel for burning cement, sufficient thermal power was obtained. Further, when the ash content after combustion of the above fuel was mixed with the limestone after calcination, good quality cement was obtained even when the ash content was increased to about 30% by weight.

[0024]

As described in detail above, the method and apparatus for treating mud-like waste of the present invention has not been available until now, either by incineration or use for disposal or landfill. By treating muddy waste with high water content from aqueous waste such as sewage and various wastewater without burning, it is possible to obtain a dry solid component with a uniform particle size and a low water content of several to ten and several percent. It is possible to recover. In addition, the system of the present invention does not generate smoke or odor during the treatment of mud-like waste, does not adversely affect the work environment or the surrounding environment, can be treated in a short time, and is low in cost. Since it can be operated at 1, and there are almost no mechanical moving parts, it is less worn and the life of the device itself is extremely long. Further, since the dry solid component obtained according to the present invention is a fine powder having a uniform particle size as described above, a low water content, no odor, and a high calorie content,
It can be used instead of fuel, especially COM. Further, the ash content remaining after combustion of the fuel containing the dry solid component of the present invention is suitable as the inorganic ash content of cement, and provides good quality cement.

[Brief description of drawings]

FIG. 1 is a drawing schematically showing an embodiment of a muddy waste treatment device according to the present invention.

[Explanation of symbols]

 1 Muddy Waste Treatment Device 2 Raw Material Tank 3 Raw Material Supply Hopper 4 Screw Conveyor 5 Jet Burner 6 Housing 7 Gravity Sedimenter 8,11 Separated Powder Receptor 9,12 Solid Component Recovery Section 10 Cyclone 13 Deodorizer 14-18 Conduit

Claims (5)

[Claims] 1. (a) 100 after completely burning mud-like waste
Contacting with a combustion gas at 0 to 2000 ° C. to convert the muddy waste into a vaporized component and a dry solid component in powder form, and (b)
A method for treating mud-like waste, comprising separating the vaporized component and the dry solid component, discharging the vaporized component, and collecting the dry solid component. 2. A drying unit, which is contacted with combustion gas at 1000 to 2000 ° C. after complete combustion to convert the mud-like waste into a vaporized component and a powdery dry solid component, connected to the drying unit, and Separation part for separating vaporized component and dry solid component, solid component recovery part for introducing and recovering dry solid component from the separating part, vaporized component discharge for introducing and discharging vaporized component from the separating part An apparatus for treating mud-like waste, comprising: 3. A powdery dry solid component recovered by the method according to claim 1. 4. A fuel containing the dry solid component in powder form according to claim 3. 5. A cement containing ash remaining after burning the powdery dry solid component according to claim 3.