TW202108257A - Sludge processing method and cement manufacturing system - Google Patents

Abstract

This cement manufacturing system comprises: a suspension pre-heater for pre-heating a cement raw material; a calcining furnace for calcining the pre-heated cement raw material; and a firing furnace for firing the calcined cement raw material. In the cement manufacturing system, a granular material containing dried sludge is loaded into a region of the suspension pre-heater having a temperature of at least 600 DEG C and less than 800 DEG C, and the dried sludge is used as a cement raw material and fuel.

Description

Sludge treatment method and cement manufacturing system

The present invention relates to a sludge treatment method and a cement manufacturing system using sludge.

The cement manufacturing process is roughly divided into the raw material steps of drying, pulverizing, and blending cement raw materials, the firing step of firing intermediate products, namely clinker, from the raw materials, and adding gypsum to the clinker and pulverizing to make cement. The final processing steps. In the firing step, usually, cement raw materials pass through a preheater, a pre-calcining furnace (calcining furnace), and a firing furnace in sequence. As the heat energy of the firing step, it is proposed to use the combustion heat of sewage sludge or factory wastewater sludge, and then use the incineration ash as a raw material for cement. Patent Documents 1 and 2 disclose techniques for using sludge in the cement firing step.

Patent Document 1 discloses that a solvent for imparting fluidity is added to waste containing organic matter, and after pulverization with a wet pulverizer, the slurry-like mixed and pulverized product is thrown into the firing step to produce cement Clinker. As the solvent, sludge is proposed. In addition, as the input location of the slurry-like mixed and crushed product, a high temperature section of 800°C to 1000°C of a preheater is proposed.

Patent Document 2 discloses that in the case of using a cement burning device in which the pre-burning furnace is directly connected to the lowermost cyclone, the water-containing sludge is injected from the outlet of the pre-burning furnace to the lowermost cyclone outlet. In the area, when the pre-burning furnace is not directly connected to the lowermost cyclone, the water-containing sludge is poured into the area from the inlet of the lowermost cyclone to the outlet of the lowermost cyclone. The ambient temperature of the place where the water-containing sludge is input is above 800°C and below 900°C. Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2004-123513 Patent Document 2: Japanese Patent Application Publication No. 2009-95804

[The problem to be solved by the invention]

In Patent Document 1, the occurrence of dioxin is prevented by feeding sludge containing a relatively large amount of water, such as a slurry-like mixed and pulverized material, to a portion of 800°C or higher of the preheater. In Patent Document 2, the water-containing sludge can be efficiently dried by feeding the water-containing sludge to a position above 800°C of the preheater, and the heat required to raise the temperature of the sludge can be reduced to suppress the effect of the cement burning device. Heat loss.

The applicant of this case proposed in Japanese Patent Application 2018-006471: by mixing dewatered sludge with cement raw materials to form granules, contacting them with drying gas to dry, and throwing the obtained granular mixture into In the pre-burning furnace of the cement burning step. Since the dry gas at a lower temperature than the temperature in the pre-sintering furnace is used in the drying of the mixture, the dried mixture contains more moisture compared with ordinary cement raw materials, and is put into the pre-sintering furnace The temperature of the mixture is lower than the temperature in the pre-burning furnace.

If a mixture whose temperature is lower than the temperature in the furnace is put into the pre-burning furnace, there is a concern that the combustion state will be disturbed or the fuel consumption will increase. In addition, there is a concern that a local temperature drop will occur near the inlet of the mixture, the life of the refractory coating will decrease, or the coating may be formed.

Therefore, the present invention proposes a method for treating sludge that uses sludge as a part of cement raw materials and fuel, and a technology for stabilizing operation in a cement manufacturing system using sludge. [Means to Solve the Problem]

The sludge treatment method of one aspect of the present invention is A method for treating sludge using a cement manufacturing system. The cement manufacturing system includes: a suspension preheater for preheating cement raw materials, a pre-burning furnace for pre-burning the preheated cement raw materials, and a A firing furnace for firing the above-mentioned cement raw materials; It is characterized in that the granular material containing dried sludge is put into the temperature range of 600°C or higher and lower than 800°C of the suspension preheater, and the dried sludge is used as a cement raw material and fuel.

In addition, the cement manufacturing system of one aspect of the present invention is characterized by having: A suspension preheater for preheating cement raw materials, a pre-burning furnace for pre-burning the above-mentioned pre-heated cement raw materials, and a firing furnace for burning the above-mentioned pre-fired cement raw materials; and The above-mentioned suspension preheater has at least one input port for inputting granular materials including dried sludge into a temperature range of 600°C or higher and lower than 800°C.

In the above-mentioned sludge treatment method and cement manufacturing system, granular materials including dry sludge are fed into the temperature range of 600°C or higher and lower than 800°C of the suspension preheater. During the movement of the granular material from the input port (input position) of the suspension preheater to the pre-sintering furnace, it is heated together with the cement raw material to the input temperature into the pre-sintering furnace (approximately 850℃～900℃) .

Compared with the conventional case of putting into the area above 800℃ as in Patent Documents 1 and 2, in the present invention, the residence time of the granular material in the suspension preheater is longer, and the granular material and the cement raw material are fully pre-prepared together. Put it into the pre-burning furnace after heating. Therefore, it is possible to suppress the disturbance of the combustion state or the increase in fuel consumption caused by the introduction of low-temperature materials into the pre-burning furnace. This can help stabilize the operation of the system in a cement manufacturing system that uses sludge as a part of the cement raw material and fuel.

Furthermore, compared with the above-mentioned conventional situation, in the present invention, the temperature difference between the ambient temperature to the input port (input position) of the suspension preheater and the temperature of the granular material is small. Therefore, the temperature drop of the granular material in the vicinity of the input port can be suppressed, and the life span of the refractory coating can be suppressed or the generation of the coating can be suppressed. [Effects of the invention]

According to the present invention, it is possible to propose a method for treating sludge that uses sludge as a part of cement raw material and fuel, and a technology for stabilizing operation in a cement manufacturing system using sludge.

Next, the implementation mode of the present invention will be described with reference to the drawings. Fig. 1 is a systematic schematic diagram showing a cement manufacturing system 100 according to an embodiment of the present invention.

The cement manufacturing process is roughly divided into the raw material steps of drying, pulverizing, and blending cement raw materials, the firing step of firing intermediate products, namely clinker, from the raw materials, and adding gypsum to the clinker and pulverizing to make cement. The final processing steps. In the cement manufacturing system 100 shown in FIG. 1, the cement sintering device 2 and the air quenching cooler 3 in charge of the sintering step, and the peripheral equipment thereof are described in detail.

The cement manufacturing system 100 includes a cement firing device 2 for firing cement raw materials, and an air quenching cooler 3 for cooling the fired product output from the cement firing device 2.

The cement firing device 2 has: a suspension preheater (hereinafter referred to as "preheater 21") for preheating cement raw materials, a precalcining furnace 22 for prefiring (decomposing) the preheated cement raw materials, and A firing furnace 23 for firing the preheated and prefired cement raw materials.

In the cement firing device 2, the cement raw materials are sequentially moved to the preheater 21, the pre-sintering furnace 22, and the firing furnace 23 to communicate with each other. In addition, in the cement sintering device 2, the high-temperature exhaust gas of the sintering furnace 23 flows in the order of the pre-sintering furnace 22 and the preheater 21. The preheater 21 is connected to a firing device exhaust gas line 9 that flows out of the cement firing device 2. In the exhaust gas line 9 of the firing apparatus, a boiler 91, an exhaust fan 92, a raw material crusher 93, a dust collector 94, an exhaust fan 95, and a chimney 96 are installed in this order from the upstream of the flow of exhaust gas to the downstream.

FIG. 2 is a block diagram showing the schematic structure of the preheater 21. As shown in FIG. The preheater 21 shown in FIG. 2 has a plurality of cyclone-type dust collectors connected in series. The preheater 21 of this embodiment includes five cyclone units U1 to U5 connected in series from the pre-burning furnace 22 upward. However, the number of stages of the cyclone unit U included in the preheater 21 may be 3 or more.

Each cyclone unit U has: a cyclone C, a duct D that introduces airflow to the cyclone C, and a pipe B. The pipe B will use the cyclone C to separate solids from the airflow to the cyclone unit U that is lower than it. At least one of the duct D, the pre-sintering furnace 22 and the firing furnace 23 is transported. In addition, in Fig. 2, the numbers after B, C, D, and U indicate the number of segments.

The first cyclone unit U1 at the bottom stage includes: a first cyclone C1, a first duct D1, and a first pipe B1. The air inlet of the first cyclone C1 is connected to the outlet of the pre-burning furnace 22 through the first duct D1. The solid outlet of the first cyclone C1 is connected to the connection part of the firing furnace 23 and the pre-sintering furnace 22 through the pipe B1.

The second cyclone unit U2 of the second stage from below includes: a second cyclone C2, a second duct D2, and a second pipe B2. The gas outlet of the first cyclone C1 is connected to the gas inlet of the second cyclone C2 through the second duct D2. The solid outlet of the second cyclone C2 is connected to the calciner 22 through the pipe B2.

The third cyclone unit U3 of the third stage from below includes: a third cyclone C3, a third duct D3, and a third pipe B3. The gas outlet of the second cyclone C2 is connected to the gas inlet of the third cyclone C3 through the third duct D3. The solid outlet of the third cyclone C3 is connected to the second duct D2 through the pipe B3.

The fourth cyclone unit U4 in the fourth stage from below includes: a fourth cyclone C4, a fourth duct D4, and a fourth pipe B4. The gas outlet of the third cyclone C3 is connected to the gas inlet of the fourth cyclone C4 through the fourth duct D4. The solid outlet of the fourth cyclone C4 is connected to the third duct D3 through the pipe B4.

The fifth cyclone unit U5 at the top stage includes: a fifth cyclone C5, a fifth duct D5, and a fifth pipe B5. The gas outlet of the fourth cyclone C4 is connected to the gas inlet of the fifth cyclone C5 through the fifth duct D5. The solid outlet of the fifth cyclone C5 is connected to the fourth duct D4 through the pipe B5. The gas outlet of the fifth cyclone C5 is connected to the upstream end of the exhaust gas line 9 of the burning device.

In the preheater 21 of the above-mentioned structure, the high-temperature exhaust gas from the sintering furnace 23 flows into the first cyclone C1 through the pre-sintering furnace 22 and the first duct D1. The exhaust gas moves from the cyclone C1 at the bottom to the cyclone C5 at the top. That is, the exhaust gas passes through the first cyclone C1, the second duct D2, the second cyclone C2, the third duct D3, the third cyclone C3, the fourth duct D4, the fourth cyclone C4, the fifth duct D5, and The fifth cyclone C5.

The fifth duct D5 is provided with a cement raw material supply port 28. The cement raw material is supplied to the fifth duct D5 through the cement raw material supply port 28. The cement raw material supplied to the fifth duct D5 flows into the fifth cyclone C5 along with the flow of the exhaust gas. In the fifth cyclone C5, the cement raw material is separated from the flow of the exhaust gas, and the cement raw material is transported to the fourth duct D4 through the pipe B5. The cement raw material conveyed to the fourth duct D4 flows into the fourth cyclone C4 along with the flow of the exhaust gas. In the fourth cyclone C4, the cement raw material is separated from the flow of the exhaust gas, and the cement raw material is transported to the third duct D3 through the pipe B4.

The third duct D3 is provided with an inlet 29 for the mixture to be described later. The injection inlet 29 is connected to a mixture supply line 8 (conveyance line 84) described later. The cement raw materials sent from the fourth cyclone C4 to the third duct D3, and the cement raw materials and the mixture (granular matter) supplied to the third duct D3 through the inlet 29 flow into the third cyclone C3 along with the flow of the exhaust gas. in. In the third cyclone C3, the cement raw materials (including the mixture) are separated from the flow of the exhaust gas, and the cement raw materials are transported to the second duct D2 through the pipe B3. The cement raw material conveyed to the second duct D2 flows into the second cyclone C2 along with the flow of the exhaust gas. In the second cyclone C2, the cement raw material is separated from the flow of the exhaust gas, and the cement raw material is transported to the pre-burning furnace 22 through the pipe B2. The exhaust gas of the pre-burning furnace 22 flows into the first cyclone C1 through the first duct D1. In the first cyclone C1, the cement raw material is separated from the flow of the exhaust gas, and the cement raw material is transported to the connection part of the firing furnace 23 and the pre-sintering furnace 22 through the pipe B1. In this way, in the preheater 21, the cement raw materials (including the mixture) sequentially move from the cyclone C5 of the uppermost stage to the cyclone C1 of the lowermost stage. The cement raw material of the preheater 21 is heated by heat exchange with the waste gas of the pre-burning furnace 22 as it passes through the cyclones C.

The calcining furnace 22 includes a calcining furnace burner 25. The pre-sintering furnace 22 is connected with an air extraction duct 41 for the pre-sintering furnace that conveys waste heat from the air quenching cooler 3 to the pre-sintering furnace 22. In the pre-burning furnace 22, the cement raw materials and the mixture output from the pre-heater 21 are pre-burned in an environment of about 900°C. In this embodiment, the temperature of the exhaust gas flowing into the first duct D1 is approximately 900°C, the temperature of the exhaust gas flowing into the second duct D2 is approximately 850°C, and the temperature of the exhaust gas flowing into the third duct D3 is approximately The temperature of the exhaust gas flowing into the fourth duct D4 is about 600°C, the temperature of the exhaust gas flowing into the fifth duct D5 is about 450°C, the exhaust gas output from the cyclone C5 to the exhaust gas line 9 of the burning device The temperature is about 310°C. However, the temperature of the exhaust gas flowing into each duct D is only an example.

Returning to Fig. 1, in this embodiment, the firing furnace 23 adopts a horizontally long cylindrical rotary kiln, that is, a rotary kiln. The firing furnace 23 is installed with a gradient slightly lowered from the raw material inlet to the raw material outlet. The firing furnace 23 includes a burner 26 on the raw material outlet side. In the firing furnace 23, the preheated and calcined cement raw materials in the preheater 21 and the calciner 22 are fired using the waste heat of the air quenching cooler 3 and the combustion gas of the burner 26.

The outlet of the firing furnace 23 is connected to the inlet of the air quenching cooler 3. In the air quenching cooler 3, the high-temperature fired product output from the firing furnace 23 is brought into contact with cold air, and the fired product is quenched to become clinker. The clinker output from the air quenching cooler 3 is transported to the clinker storage bin by the clinker conveyor 32.

The air quenching cooler 3 is connected with a cooler waste heat line 4 that flows out of the waste heat of the air quenching cooler 3. The cooler waste heat line 4 includes: the exhaust duct 41 for the above-mentioned pre-combustion furnace, the high temperature waste heat line 42 that draws air from the air quenching cooler 3, and the low temperature that draws waste heat below about 200°C from the air quenching cooler 3 Waste hotline 43.

The high-temperature waste heat line 42 is connected to the boiler 45. Through the high temperature waste heat line 42, the exhaust gas of the air quenching cooler 3 is sent to the boiler 45.

In the low-temperature waste heat line 43, the dust collector 46, the exhaust fan 47 and the chimney 48 are arranged in sequence from the upstream of the flow of the exhaust gas to the downstream. In this embodiment, the exhaust gas line 45a of the boiler 45 is connected to the lower-temperature waste heat line 43 on the upstream side of the dust collector 46.

The cement manufacturing system 100 further includes: a mixing device 5 for mixing dewatered sludge and cement raw materials to form a granular mixture, a dryer 6 for drying the mixture by contacting the mixture with a drying gas, and drying The exhaust gas line of the dryer 6 is conveyed to the air quenching cooler 3, the exhaust gas line 7 of the dryer is conveyed from the dryer 6 to the preheater 21 of the cement burning device 2, and the mixture supply line 8 of the dried mixture is conveyed to the dryer 6 A drying gas supply line 61 for supplying drying gas.

The mixing device 5 includes a cement raw material hopper 51, a dewatered sludge hopper 52, and a mixer 53 that mixes and sends out the cement raw material and the dewatered sludge.

The cement raw material hopper 51 is charged with the cement raw material dried, crushed, and blended in the raw material step. The cement raw material may be the same as the cement raw material supplied to the cement raw material supply port 28 of the preheater 21. The cement raw material is a well-known raw material mainly composed of limestone, and is not particularly limited. If cement raw materials are specifically exemplified, limestone is usually the main material, and clay, silica, iron oxide, etc. are blended and used. As an example, the chemical composition of cement raw materials includes: 12-15% by mass of SiO ₂ , 3-4% by mass of Al ₂ O ₃ , 1.5-2.5% by mass of Fe ₂ O ₃ , 43-44% by mass of CaO, 0.6 ~0.9% by mass of MgO, 35 to 37% by mass of volatile components, and 0 to 1% by mass (the remainder) of other materials.

In the dewatered sludge hopper 52, the dewatered sludge is put in. Dewatered sludge is the residual solid matter (de-cemented cake) of sewage sludge, factory wastewater sludge, activated sludge and other sludge that is dewatered by a dehydrator (not shown). The dehydrated sludge that is usually treated as a dehydrated cake contains 60 to 90% by mass of moisture.

The outlet of the cement raw material hopper 51 is connected to the inlet of the mixer 53 through the cement raw material adjusting device 55. The cement raw material adjusting device 55 adjusts the cement raw material conveyed from the cement raw material hopper 51 to the mixer 53. In addition, the outlet of the dewatered sludge hopper 52 is connected to the inlet of the mixer 53 through the sludge adjusting device 56. The sludge adjusting device 56 adjusts the dewatered sludge conveyed from the dewatered sludge hopper 52 to the mixer 53. The mixing ratio of the dewatered sludge to the cement raw material in the mixer 53 is the mass ratio or volume ratio of the dewatered sludge to the cement raw material when the mixture of the dewatered sludge and the cement raw material becomes granular.

When the mixing ratio of dewatered sludge and cement raw materials is within a specific range, the mixture of dewatered sludge and cement raw materials will become granular without undergoing granulation treatment. The mixing ratio of dewatered sludge and cement raw materials is not fixed, and varies according to the properties of the dehydrated sludge (especially the proportion of external moisture or organic matter) or the properties of the cement raw materials (especially the internal moisture or composition). Therefore, the mixing ratio of dewatered sludge and cement raw materials is ideally set according to the degree of change in the properties of dewatered sludge and cement raw materials each time. The range of the mixing ratio of the dewatered sludge and the cement raw material can be determined by experiments, for example.

In this embodiment, since a fluidized bed dryer is used as the dryer 6, the mixing ratio of the dewatered sludge and the cement raw material is desirably set as the mixture as the fluid medium to have an appropriate granular value. Specifically, the mixing ratio of dewatered sludge and cement raw materials is experimentally determined so that the total moisture content of the mixture is 10% by mass or more and 25% by mass or less, ideally 13% by mass or more and 22% by mass or less. And set in the control device 57 in advance. The control device 57 controls the cement raw material regulating device 55 and the sludge regulating device 56 to obtain the mixing ratio of the dewatered sludge and the cement raw material. The total moisture of the mixture is the sum of the attached moisture on the surface of the mixture, that is, the external moisture, and the adsorbed moisture of the mixture, that is, the internal moisture. The total moisture content of the mixture is measured in accordance with the case of coal based on the moisture quantitative method specified in "JIS M 8812 Coal and Coke-Industrial Analysis Method".

According to the experiments of the inventors, if the total moisture content of the mixture is 10% by mass or more and 25% by mass or less, it is confirmed that the particle size distribution of the mixture is small (that is, the degree of unevenness in particle size is small), and the average particle size It is a granular mixture of the size suitable as a fluid medium.

The "size suitable as a flow medium" in the above refers to the diameter of particles that can flow uniformly in the layer, and the index ranges from μm to about 5 mm. In the test results of the inventors, the average particle diameter (median particle diameter d50) of the mixture with a total water content of 10% by mass or more and 25% by mass or less is 0.5 mm or more and 5 mm or less, which is suitable as a fluid medium The size.

The mixture system produced by mixing the dewatered sludge and the cement raw material by the mixer 53 is supplied to the dryer 6. In the dryer 6, a fluidized bed is formed in which the mixture is used as the fluid medium and the drying gas is used as the fluidized gas. The dryer 6 supplies a drying gas into the mixed material layer formed at the bottom of the drying chamber, and the mixed material is brought into contact with the drying gas due to the rising of the drying gas in the mixed material layer to dry the mixed material. In this way, a fluidized bed dryer with higher drying efficiency (that is, a larger volumetric heat exchange rate) compared with other types of dryers is used as the dryer 6. However, the dryer 6 is not limited to a fluidized bed dryer.

The drying gas is sent to the dryer 6 through the drying gas supply line 61. The air volume (wind speed) of the drying gas supplied to the dryer 6 is such that the proper fluidization state of the fluidized bed of the dryer 6 can be obtained, and according to the properties of the mixture (ie, particle size, moisture, density, etc.), Use baffle or fan to adjust. In this embodiment, as the drying gas, waste gas from the cement manufacturing process or heat from the process is used, and waste gas above 50°C and lower than 200°C is used. Among such exhaust gases, for example, the exhaust gas below 200°C from the air quenching cooler 3, the exhaust gas below 200°C from the boiler 45 using the exhaust gas of the air quenching cooler 3, and the exhaust gas from the cement burning device 2 are proposed. The waste gas of the raw material crusher 93 below 200°C, etc.

The mixture dried by the dryer 6 is discharged from the bottom of the drying chamber, and is supplied to the calciner 22 through the mixture supply line 8. The mixture supplied to the pre-sintering furnace 22 is not particularly limited, and the moisture content may be about 2 to 5 mass%, and the temperature may be about 60 to 100°C. The mixture supply line 8 includes: conveyors 81 and 82 for carrying out the dried mixture from the dryer 6; a mixture hopper 83 for temporarily storing the mixture; and a quantitative discharge of the mixture from the mixture hopper 83 Transport line 84 of transport. The mixture supplied to the pre-sintering furnace 22 by the mixture supply line 8 is used as a part of the fuel, and further, the combustion ash of the mixture is used as a part of the cement raw material.

The exhaust gas of the dryer 6 is supplied to the air quenching cooler 3 through the exhaust gas line 7 of the dryer. In the dryer exhaust gas line 7, the dust collector 71, the exhaust fan 72 and the blowing fan 74 are arranged in sequence from the upstream of the flow of the dryer exhaust gas to the downstream. The exhaust gas of the dryer discharged from the dryer 6 by the exhaust fan 72 is used by the dust collector 71 to remove the accompanying dust. The removed dust is transported from the dust collector 71 to the mixed material hopper 83 and supplied to the pre-burning furnace 22 together with the mixed material stored in the mixed material hopper 83. The dryer exhaust gas passing through the dust collector 71 is supplied to the air quenching cooler 3 by the blower fan 74.

As explained above, the cement manufacturing system 100 of this embodiment includes: a preheater 21 for preheating cement raw materials, a preburning furnace 22 for preburning the preheated cement raw materials, and a The sintering furnace 23 for sintering cement raw materials; the preheater 21 has at least one input port 29 for inputting granular materials containing dried sludge into a temperature range of 600°C or higher and lower than 800°C.

In addition, the sludge treatment method of this embodiment is a method of using the cement manufacturing system 100 to process sludge. The cement manufacturing system 100 is provided with a preheater 21 for preheating the cement raw materials, and a preheater for the preheated cement. The pre-burning furnace 22 for pre-burning raw materials and the burning furnace 23 for burning the pre-burned cement raw materials; and the granular material containing dry sludge is put into the preheater 21 at a temperature above 600°C and below In the temperature range of 800°C, dry sludge is used as cement raw material and fuel.

In this embodiment, the above-mentioned "granular matter containing dried sludge" is a mixture of dried sludge and cement raw materials. Therefore, the cement manufacturing system 100 of this embodiment further includes: a mixing device 5 for mixing dewatered sludge and cement raw materials to obtain a granular mixture, a dryer 6 for drying the mixture, and a drying machine 6 The conveying line 84 for conveying the dried mixture to the input port 29 as a granular substance.

However, the particulate matter containing dry sludge is not limited to a mixture of dry sludge and cement raw materials. For example, the granular material containing dried sludge may be a crushed product of dried sludge, or a mixture of raw sludge and dried sludge. In addition, the size of the granular material may be such that the exhaust gas from the pre-burning furnace 22 can be used for air flow conveyance, and it may be in the form of powder, flakes, or agglomerates.

In the above-mentioned sludge processing method and cement manufacturing system 100, granular materials including dry sludge are fed into the temperature range of 600°C or higher and lower than 800°C of the preheater 21. During the movement of the granular material from the input port 29 (input position) in the preheater 21 to the pre-sintering furnace 22, it is heated together with the cement raw materials to the input temperature of the pre-sintering furnace 22 (approximately 850°C to 900°C). ).

Compared with the conventional case of putting into the area above 800°C as described in Patent Documents 1 and 2, in the present invention, the granular material stays in the preheater 21 for a long time, and is put into the pre-sintering furnace after sufficient preheating 22 in. Therefore, it is possible to suppress the disturbance of the combustion state or the increase in fuel consumption caused by the introduction of low-temperature substances into the pre-burning furnace 22. Moreover, compared with the above-mentioned conventional case, the temperature difference between the ambient temperature of the input port 29 (input position) in the preheater 21 and the granular material is small. Therefore, the temperature drop in the vicinity of the granular material input port 29 can be suppressed, and the life span of the refractory coating can be suppressed or the generation of the coating can be suppressed. As a result, in the cement manufacturing system 100 that uses sludge as a part of the cement raw material and fuel, it can contribute to the stabilization of the operation of the system.

In the cement manufacturing system 100 of the present embodiment, the preheater 21 includes three or more cyclone units U1 to U5 connected in series from the pre-sintering furnace 22 upward. The cyclone units U1～U5 respectively have: cyclones C1～C5, ducts D1～D5 for introducing airflow into the cyclones C1～C5, and pipes B1～B5. The pipes B1～B5 will use the cyclones C1～C5 to flow from the air. The solid separated in the middle is transported to at least one of the ducts D1 to D4 of the cyclone unit U1 to U4, the pre-sintering furnace 22 and the firing furnace 23 at the lower stage.

From the viewpoint of extending the residence time in the preheater 21, the input port 29 is ideally provided in the duct D of the cyclone unit U at the upper stage in the temperature region of 600°C or higher of the preheater 21. Therefore, in this embodiment, an inlet 29 is provided near the inlet of the duct D3 of the cyclone unit U3 at the third stage from below. In addition, although the temperature of the exhaust gas flowing into the duct D2 of the cyclone unit U2 at the second stage from the bottom is about 850°C, the temperature drops immediately afterwards to be lower than 800°C, so it can also be installed in the duct D2.口29. In this way, in the cement manufacturing system 100 of this embodiment, at least one of the ducts D2 and D3 of the second and third stages of the cyclone unit U2 and U3 from below can be provided with an input port 29. In other words, granular materials can be injected into at least one of the ducts D2 and D3 of the cyclone units U2 and U3 in the second and third stages from below. However, the position of the input port 29 can be adjusted appropriately according to the preheater 21 of each cement manufacturing system 100.

If the granular material containing dry sludge is fed into the temperature region of the preheater 21 below 600°C, the odor generated from the sludge contained in the granular material is not decomposed by heat and is transferred to the waste gas of the burning device. Line 9 is discharged. Therefore, a device for decomposing odors is required in the exhaust gas line 9 of the burning device. In addition, the temperature range of 800°C or higher of the preheater 21 is roughly specified as the first duct D1 that connects the calciner 22 and the cyclone C1 at the lowermost stage. If the granular material containing dry sludge is put into the first duct D1 of the preheater 21, the granular material only passes through the first cyclone unit U1 in the preheater 21, so there is a risk of insufficient temperature rise, making it difficult The temperature drop in the vicinity of the granular material input port 29 is suppressed.

The preferred embodiments of the present invention have been described above, but within the scope of the idea of the present invention, changes to the specific structure and/or function details of the above embodiments are also included in the present invention.

2: Cement burning device 3: Air quenching cooler 4: Cooler waste heat line 5: Mixing device 6: Dryer 7: Dryer exhaust line 8: Mixture supply line 9: Exhaust gas line of burning device 21: Suspended preheater 22: pre-burning furnace 23: Firing furnace 25: Burn-in furnace burner 26: Burner 28: Cement raw material supply port 29: Put in the mouth 32: Clinker conveyor 41: Exhaust duct for pre-burning furnace 42: High temperature waste hotline 43: Low temperature waste hotline 45: boiler 45a: exhaust line 46: Dust Collector 47: Exhaust fan 48: Chimney 51: Cement raw material hopper 52: Dewatered sludge hopper 53: Mixer 55: Cement raw material regulator 56: Sludge adjustment device 57: control device 61: Gas supply line for drying 71: Dust Collector 72: Exhaust fan 74: blower fan 81: Conveyor 82: Conveyor 83: Mixed material hopper 84: transfer line 91: boiler 92: exhaust fan 93: Raw material crusher 94: Dust Collector 95: exhaust fan 96: Chimney 100: Cement manufacturing system B, B1～B5: Piping C, C1～C5: Cyclone D, D1～D5: Catheter U, U1～U5: Cyclone unit

[Fig. 1] is a schematic structural diagram showing the systemic structure of the cement manufacturing system of the embodiment of the present invention. [Figure 2] is a block diagram showing the schematic configuration of the suspension preheater.

8: Mixture supply line

9: Exhaust gas line of burning device

21: Suspended preheater

22: pre-burning furnace

23: Firing furnace

25: Burn-in furnace burner

28: Cement raw material supply port

29: Put in the mouth

41: Exhaust duct for pre-burning furnace

84: transfer line

B1~B5: Piping

C1~C5: Cyclone

D1~D5: Catheter

U1~U5: Cyclone unit

Claims (6)

A method for treating sludge, using a cement manufacturing system to process sludge. The cement manufacturing system is equipped with: a suspension preheater for preheating cement raw materials, a preburning furnace for preheating the preheated cement raw materials, And a firing furnace for firing the above-mentioned pre-fired cement raw materials; and The granular material containing dried sludge is put into the temperature range of 600°C or higher and lower than 800°C of the above-mentioned suspension preheater, and the above-mentioned dried sludge is used as a cement raw material and fuel. Such as the treatment method of sludge in claim 1, where The above-mentioned suspension preheater is provided with three or more stages of cyclone units connected in series from the above-mentioned pre-burning furnace toward the upper side; The cyclone unit has a cyclone, a duct for introducing airflow into the cyclone, and a pipe. The pipe will use the cyclone to separate solids from the airflow to the cyclone unit lower than the solid. At least one of the catheter, the above-mentioned pre-sintering furnace and the above-mentioned firing furnace is transported; and Put the granular substance into at least one of the ducts of the cyclone unit in the second and third stages from below. Such as the sludge treatment method of claim 1 or 2, where The granular material is a mixture of the dried sludge and the cement raw material. A cement manufacturing system comprising: a suspension preheater for preheating cement raw materials, a pre-sintering furnace for pre-burning the above-mentioned pre-heated cement raw materials, and a firing for firing the pre-fired above-mentioned cement raw materials Furnace; and The above-mentioned suspension preheater has at least one input port for inputting granular materials including dried sludge into a temperature range of 600°C or higher and lower than 800°C. Such as the cement manufacturing system of claim 4, where The above-mentioned suspension preheater is provided with three or more stages of cyclone units connected in series from the above-mentioned pre-burning furnace toward the upper side; The cyclone unit has a cyclone, a duct for introducing airflow into the cyclone, and a pipe. The pipe will use the cyclone to separate solids from the airflow to the cyclone unit lower than the solid. At least one of the catheter, the above-mentioned pre-sintering furnace and the above-mentioned firing furnace is transported; and At least one of the above-mentioned ducts of the above-mentioned cyclone unit in the second and third sections from below is provided with the above-mentioned input port. Such as the cement manufacturing system of claim 4 or 5, which further has: Mixing device to mix dewatered sludge with cement raw materials to obtain a granular mixture; A dryer to dry the above-mentioned mixture; and The conveying line conveys the mixture dried by the dryer as the granular material to the input port.

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