JPS607960B2 - Dry sludge gasification equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Prior Art] Previously, sewage sludge was considered to be a waste that should be incinerated with supplementary fuel.

The applicant has been conducting research on the incineration of sewage sludge for many years,
He has developed a system that can self-incinerate even low-calorie sewage sludge by skillfully using its own calories and without using too much auxiliary fuel, and has filed a patent application (Hakamagao Sho 55-1169165). ).

Prior to explaining the present invention, the system for which a patent application has been filed will first be explained with reference to FIG. In Figure 1, sewage sludge that has been dehydrated to a moisture content of approximately 90% by mechanical dewatering is supplied into hopper 1, and the sewage sludge in hopper 1 is forced into a screw conveyor installed at the bottom of the hopper. The supply means 2 first supplies the sewage sludge heater 3 to the sewage sludge heater 3, and a part of the gas heated to a high temperature by the heat of the flue gas in the heat exchanger 8, which is a later step, is supplied as a heating gas. The supplied sewage sludge, which has been heated by the high-temperature heating gas while passing through the heater 3 and becomes fluid, is then supplied to a drying furnace 4 having a fluidized sand bed. A necessary amount of the gas heated to a high temperature by the heat of the flue gas in the heat exchanger 8, which is a process, is supplied as drying gas, and the dried product of the drying oven is separated into solids and gas by the separation means 5. The solid content is supplied to the stage combustion furnaces 7, 7' by the powder supply means 6, and the heating gas supplied to the heater 3 is cooled to a slightly lower temperature through the heater 3 and taken out. However, this gas is removed by drain separation means 15.
After removing the condensate, the fuel is supplied as fuel to either of the two-stage combustion furnaces 7 and 7'.

The combustion air to be supplied to the combustion furnaces 7 and 7' is
After being preheated through an air heater 14 provided as a jacket for the combustion chamber 1, it is supplied to the two-stage combustion furnaces 7, 7'. The combustion generated gas from the combustion furnace 7' is first supplied to a heat exchanger 8 for heat exchange to lower the temperature to a slightly lower temperature, then passed through a filter 9 to remove ash, and then passed through a Teizan blower 10 to be blown 9E. The separation means 5
The separated gas passes through the blower 11 and is heated by the heat exchanger 8, which raises the pressure, and is air-fed through the circulation pipe 12, and the required amount of high-pressure and high-temperature gas is sent to the drying oven 4 as a drying gas. After the required amount is supplied to the drying oven, the remaining gas is supplied to the heater 3 as a gas for heating the sewage sludge. However, subsequent research has shown that sewage sludge contains many latent resources, so it should not simply be incinerated and disposed of, but that the dried product produced by drying sewage sludge can be used as a soil improver for agriculture. is used as a raw material to produce gas fuel.
Alternatively, it has been found that the ash can be effectively used as various resources, such as by turning the ash into lumps and providing it as aggregate for cement. - Gasification equipment was developed.

〔the purpose〕

The present invention relates to an apparatus for separating the product produced by the drying oven 4 by the separating means 5, further separating the dried sewage sludge product obtained by this separation into ash and gas, and recovering gaseous fuel.

[Structure of the invention]

The dry sludge gasification apparatus of the present invention will be explained with reference to FIGS. 2 and 3 showing an embodiment thereof.

In Fig. 2, a gas burner 21 is provided at the lower part of the center shaft M
A tall cylindrical combustion chamber 22 is located around the gas burner 21.
will be established.

A dry distillation chamber 23 is provided at the outer periphery of the combustion chamber. The outer periphery of the dry distillation chamber is wrapped with a heat insulating material 24 to keep it warm. The tall cylindrical combustion chamber 22 has a rotating means 25 so that its outer peripheral wall rotates.
will be established.

Therefore, the outer circumferential wall of the combustion chamber rotates at a slow speed of about 0.8 pm to about 100 pm. Several thick floating blades 26, 26', . . . facing outward are provided on the outside of the outer peripheral wall. Dried sludge supplied from the upper part of the dry distillation chamber 23 is rope-pushed by the rope floating blades and mixed well with superheated steam and other gases supplied from the lower part of the dry distillation chamber 23, so that gas generation becomes active. Additionally, a third
As shown in the plan sectional view of the figure, several heat transfer fins 27, 27', . These inwardly directed heat transfer fins can improve the efficiency of heat transfer from the combustion chamber to the dry distillation chamber 23. It is possible to create an atmosphere of 0. A combustion exhaust gas exhaust pipe 29 is provided at the top of the combustion chamber 22 surrounded by a heat insulating material 28. The combustion exhaust gas discharged from the pipe is supplied to the heat exchanger 8. At the top of the dry distillation chamber 23 provided on the outer periphery of the combustion chamber 22, a means 30 for supplying dried sewage sludge solids is provided. Dried sludge is supplied by this coupling means 30 to the drying chamber at a constant rate every hour. A supply pipe 31 for a gas for promoting volatilization, such as a mixture of superheated steam and air, is provided in the lower part of the dry distillation chamber 23. An ash extraction section 32 is provided at the bottom of the dry distillation chamber 23. A constant amount of ash is removed every hour by the ash removal section 32. A dry distillation gas fuel take-out pipe 33 is provided at the top of the dry distillation chamber 23. [Operations and effects of the present invention] The dry sludge gasification apparatus of the present invention has the above-mentioned structure,
The dry sewage sludge solids removed by the separating means 5 in FIG. 1 is supplied.

This dried sludge is in the form of fine particles or powder with a diameter of 0.2 or less, and is dried to a moisture content of 5% or less. 30' is thus supplied in a nearly constant amount. Fourth
The figure is a graph showing the components and dry distillation characteristics of the supplied dried sludge.

As shown in Figure 4, about 50% of dried sludge is ash, and the ash extracted as a result of dry distillation is an alkali salt whose main components are Si02 and AI203, which contain considerable amounts of Na and K as salts. . These are taken out in almost constant amounts from the ash removal section 32 of this device. After removing the ash content, most of the remaining content, ie, about 45%, is volatile content, and about 5% is fixed carbon content.

In addition, FIG. 4 shows that this volatile matter is about 1.0% in the atmosphere in the dry distillation chamber 23 of 700% to 500qo. Most of the volatile matter can be dry distilled by accumulating in a stream, and 5
This indicates that dry distillation is not smooth below 00:00.
In the gasifier of the present invention, dry sludge is always kept in the dry distillation chamber 2.
Dry sludge is supplied so that its surface is at the top of the heat transfer fins 3, that is, at the upper end of the heat transfer fins, and the ash is removed.

The lower part of the dry distillation chamber 23 has a higher temperature than the upper part, but by providing heat transfer fins on the combustion chamber 22 side, the combustion chamber of the gas burner has a temperature of 120 mm, but the dry sludge accumulation part of the dry distillation chamber can be maintained in an atmosphere of 500°C to 70p○. In addition, in the dry distillation chamber 23, superheated steam for promoting volatilization is supplied, and a floating rope is used to perform the fly worship, so that the dried sludge can be decomposed and dry distilled into volatile matter and ash. A part of the gas fuel taken out from the dry distillation gas fuel extraction pipe 33 of the dry distillation chamber may be supplied to the gas burner 21 of the apparatus of the present invention, and may also be used as a fuel resource for power generation or heating. It can also be supplied to a boiler to create superheated steam.

The ash extracted from the ash extraction section 32 of the dry distillation chamber can be used as a gravel substitute for concrete by a separate dry sludge ash processing device.

[Brief explanation of the drawing]

FIG. 1 shows a sewage sludge incineration system that the applicant and inventor of the present invention previously applied for a patent and developed. FIG. 2 is a front sectional view showing the dry sewage sludge solid gasification apparatus of the present invention. FIG. 3 is a plan cross-sectional view of the gasifier Hishitaka shown in FIG. 2. FIG. 4 is a graph showing the components and dry distillation characteristics of the dried sewage sludge solids supplied to the present gasifier. 2
1 is a gas burner, 22 is a combustion chamber, 23 is a dry distillation chamber, 24 is a heat insulating material, 25 is a means for rotating the peripheral wall of the combustion chamber, 26 is a foundation blade, 27 is a heat transfer fin, 28 is a heat insulating material, and 29 is a combustion exhaust gas a discharge pipe, 30 a supply means for dry sewage sludge solids;
1 is a gas supply pipe for promoting volatilization, 32 is an ash extraction section, and 33 is a gas transfer pipe. Purple 1st figure Jie Z figure 3rd figure New 4th figure

Claims (1)

[Claims] 1. A gas burner 21 is provided at the lower part of the central shaft portion, a tall cylindrical combustion chamber 22 is provided around the gas burner 21, a dry distillation chamber 23 is provided on the outer periphery of the combustion chamber, and a rotating means for rotating the outer peripheral wall of the combustion chamber 22. A stirring blade 25 is provided, and several stirring blades 26, 26' are provided by being fixed to the outer peripheral wall of the combustion chamber and protruding outward,
Heat transfer fins 27, 27', .
A gas supply pipe 31 for promoting volatilization is provided at the bottom, an ash removal section 32 is provided at the bottom, a dry distillation gas fuel removal pipe 3 is provided at the top, and a combustion exhaust gas discharge pipe 29 is provided at the top of the combustion chamber 22.
A dry sludge gasification device with a structure equipped with.