JPS6237290B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to waste sludge, in which a melting point depressing material is mixed into waste sludge, which is a material to be treated, in a mixer before being input into a furnace, and the mixture from the mixer is heated and melted in the furnace. Regarding processing method. To explain further, the waste sludge is heated and melted to make it low in bulk and free of harmful substances, which can be used later as landfill material, aggregate, roadbed material, etc. However, when waste sludge is heated and melted, a melting point depressing material is mixed into the waste sludge using a mixer.
The present invention relates to a waste sludge treatment method that does not require a large amount of fuel, severely damage the furnace, and generate more nitrogen oxides. [Prior Art] Conventionally, river sand was mixed into waste sludge as a melting point lowering material to lower the melting point of the waste sludge. [Problems to be solved by the invention] However, since river sand is a resource that is quite expensive and difficult to obtain, it not only increases costs, but also requires melting to melt river sand that does not originally require melting. The amount of material was larger than necessary, which was a disadvantage of reducing the amount of residue, which is an advantage of melt processing. The purpose of the present invention is to lower the melting point of waste sludge by extremely rational means, to make it economically advantageous, to save resources, and to prevent unnecessary increases in the amount of molten material. be. [Means for Solving the Problems] The characteristic means of the present invention is to use municipal waste incineration ash as a melting point depressing material that is mixed into the waste sludge in a mixer before being introduced into the furnace, and its effects are as follows. It is as follows. [Function] In other words, municipal waste incineration ash contains abundant silica, etc., and if an appropriate amount of municipal waste incineration ash is mixed in with a mixer in advance, the melting point of waste sludge can be sufficiently lowered. In this way, by making effective use of municipal waste incineration ash, which is rather difficult to dispose of, heating and melting treatment of waste sludge can be carried out extremely economically, without requiring effective resources, and by reducing the amount of molten material unnecessarily. This can be done without increasing. [Effects of the invention] As a result, when waste sludge is heated and melted to lower its melting point, the cost of materials for lowering the melting point can be eliminated, making it advantageous in terms of resource conservation, and eliminating unnecessary increases in the amount of molten material. As a whole, we were able to establish a melting point lowering technology that is extremely suitable for heating and melting treatment of waste sludge. [Example] Next, an example will be shown. As shown in FIG. 1, a hopper 2 for supplying coke is provided at the top of a vertical furnace 1,
Furnace 1 is opened and closed by gate 4 and bell 5 by a and 3b.
An appropriate amount of coke is supplied into the furnace to form a high-temperature hearth 6 made of burnt coke in the lower part of the furnace. The hearth 6 is ignited by a burner 7, and after ignition, the burner 7 is stopped and the combustion of the hearth 6 is continued by preheated air supplied from a blower 8 via a heat exchanger 9. Preheating air is supplied from a lower supply route 10a to the middle part of the hearth 6, an intermediate supply route 10b to the upper surface of the hearth 6, and an upper supply route 10c to the upper space of the hearth, and the preheated air is supplied from the lower supply route 10a to the middle part of the hearth 6, and the upper supply route 10c to the upper space of the hearth. While maintaining the high temperature, complete combustion is performed by after-combustion in the upper part of the furnace 1, and the combustion gas passes through the exhaust gas passage 11 to the ash separator 12 and the heat exchanger 9.
sent to. Directly above the high-temperature hearth 6, the inner peripheral wall surface 1a of the furnace is formed into an upwardly expanding tapered surface to reduce the flow rate of rising gas from the hearth 6 and suppress the scattering of ash caused by the combustion gas. As shown in FIG. 2, waste sludge is supplied from the hopper 28 and municipal waste incineration ash is supplied from the hopper 29 to the mixer 30, and waste sludge mixed with the municipal waste incineration ash is sent from the mixer 30 to the supply hopper 13.
The waste sludge mixed with incineration ash is sent from the supply hopper 13 to the rotary feeder 14, and the waste sludge mixed with incineration ash is blown onto the upper surface of the hearth 6 by pressurized air from the blower 15, and is disposed of immediately after being supplied, regardless of the flow of combustion gas and combustion air. Sludge and incineration ash are brought into contact with a high-temperature hearth 6 and melted, and ash scattering is prevented. This waste supply system includes a fluid pressure cylinder 3c.
A supply amount adjustment shutter 16, a safety port 17, an adhesion prevention plate 18, a flow rate adjustment valve 19, etc., which are operated by a shutter 16, a safety port 17, an adhesion prevention plate 18, a flow rate adjustment valve 19, etc. are provided, and the waste supply suitable for the melting process can be maintained. The molten material is sent to the specific gravity sorting section 21 through a discharge path equipped with weirs 20a and 20b, and when the molten material is separated into two layers, the molten material with a lighter specific gravity is sent to the first outlet 2.
2, and the molten material with heavy specific gravity is taken out from the second outlet 23.
Further, the gas in the sorting section 21 is combined with the exhaust gas from the upper part of the furnace 1 through the exhaust gas pipe 11a. In the figure, 24 is a water cooling jacket for protecting the furnace.
25 is an air intake port for after-combustion, 26 is a damper for adjusting the amount of exhaust gas, and 27 is a damper for adjusting the amount of preheating air. In other words, if the waste sludge is melted using the furnace 1, the silica in the municipal waste incineration ash acts effectively, and the waste sludge can be melted at a relatively low furnace temperature. . By the way, when sewage sludge was melted alone, the melting point was 1,580°C, but when sewage sludge was mixed with municipal waste incineration ash at a weight ratio of 1:0.5 and melted, the melting point dropped to 1,320°C. The sewage sludge used in the experiment was previously incinerated, and the composition of the sewage sludge ash is shown in the table below.

[Table] The composition of the municipal waste incineration ash used in the experiment is shown in the table below.

[Another example]

Next, another embodiment will be described. The means for supplying waste sludge to the furnace 1 can be changed such that it is supplied from the hopper 2 in a mixed state with carbon-based combustible material or alternately. In addition to the above-mentioned cupola type, there are various known furnaces used for melting, such as a burner type vertical furnace and a horizontal furnace such as a rotary kiln.

[Brief explanation of the drawing]

The drawings show an example of equipment used in the present invention, with FIG. 1 being a partially omitted vertical sectional view, and FIG. 2 being a sectional view taken along the line -- in FIG. 1...Furnace, 30...Mixer.

Claims (1)

[Claims] 1. A waste sludge treatment method in which a melting point depressing material is mixed into waste sludge, which is a material to be treated, in a mixer 30 before being input into the furnace 1, and the mixture from the mixer 30 is heated and melted in the furnace 1, A waste sludge treatment method using municipal waste incineration ash as the melting point lowering material.