Liquefied flammable gas utilization device, liquefied flammable gas utilization method, and cement manufacturing equipment

Abstract

To provide a use device of a liquefied combustible gas capable of easily and inexpensively gasifying a liquefied combustible gas especially in a cement production facility.SOLUTION: There is provided, a use device of a liquefied combustible gas, the use device can be attached to a cement production facility comprising: a calcination furnace; a cement kiln; and a clinker cooler which is coupled to a part in front of a furnace of the cement kiln. The use device comprises: a tank storing the liquefied combustible gas in a liquid state; and a combustible gas pipeline which communicates the clinker cooler with a blowing part which is provided on at least one part belonging to a group formed of a calcination furnace extraction pipeline through which an extraction gas extracted from the clinker cooler is distributed to the calcination furnace. The combustible gas pipeline supplies the liquefied combustible gas or, the combustible gas obtained by being gasified during circulation of the liquefied combustible gas to the blowing part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an apparatus for utilizing liquefied flammable gas, and more particularly to an apparatus for utilizing liquefied flammable gas that can be attached to a cement manufacturing facility. The present invention also relates to a method for utilizing liquefied flammable gas, and more particularly to a method for utilizing liquefied flammable gas that can be used in a cement manufacturing process. The present invention also relates to a cement manufacturing facility that can utilize liquefied flammable gas. [Background technology]

[0002] It is known that the production of cement emits a large amount of CO2. There are two reasons for this. The first reason is that the cement manufacturing process requires burning the raw materials for cement at high temperatures in a furnace, and a large amount of fossil fuels is used to obtain the combustion energy. The second reason is that limestone, the main raw material for cement, causes a decarbonation reaction (CaCO3 → CaO + CO2).

[0003] CO2 is a greenhouse gas that has a significant impact on global warming. Therefore, cement manufacturing plants are being asked to reduce their CO2 emissions.

[0004] Against this background, the use of combustible gas fuels, which have a lower CO2 emission intensity than coal, the main fuel used in cement production, has been considered in recent years.

[0005] For example, Patent Document 1 below proposes using ammonia as an auxiliary fuel in addition to fossil fuels, which are the conventional main fuel, as fuel when producing cement. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-172484 Summary of the Invention [Problem to be solved by the invention]

[0007] To use flammable gases such as ammonia as fuel in cement production, the flammable gas must be introduced into the cement manufacturing plant. There are two possible methods for this. The first method involves constructing a gas pipeline connecting the flammable gas supplier's facility with the cement manufacturing plant, and then supplying the flammable gas in gaseous form to the cement manufacturing plant through this pipeline. The second method involves liquefying the flammable gas at the supplier's facility, transporting the liquefied flammable gas in tanks by land or sea to the cement manufacturing plant, where it is vaporized for use. However, because the first method has many problems in terms of both initial and running costs, the second method is considered to be adopted.

[0008] When the second method is adopted, as described above, the liquefied flammable gas must be vaporized at the cement manufacturing plant. A commonly known method for vaporizing liquefied ammonia is to use a vaporizer to vaporize it with hot water or steam heated by a heater. However, this method requires that the sensible heat required to raise the water temperature from ambient temperature to the hot water temperature (generally about 40°C) and the latent heat of vaporization of the liquefied ammonia be added to the liquefied ammonia as thermal energy. Considering that liquefied ammonia will be used as part of the fuel for cement production, the initial cost of installing the equipment to supply the thermal energy and the running costs during actual operation are expected to be enormous.

[0009] Such cost issues hinder the use of liquefied flammable gas as an alternative fuel in cement production, making it difficult to reduce CO2 emissions during cement production. The above-mentioned Patent Document 1 does not mention at all the above-mentioned problems that may arise when liquefied flammable gas is actually used in a cement manufacturing plant, or measures to address these problems.

[0010] In view of the above, an object of the present invention is to provide a liquefied flammable gas utilization device and a liquefied flammable gas utilization method that enable a liquefied flammable gas to be vaporized in a cement manufacturing plant in a simple and inexpensive manner. Another object of the present invention is to provide a cement manufacturing facility that can vaporize and utilize a liquefied flammable gas in a simple and inexpensive manner. [Means for solving the problem]

[0011] The present invention provides a device for utilizing liquefied flammable gas that can be attached to a cement manufacturing facility that includes a calciner for calcining cement raw materials, a cement kiln for burning the cement raw materials calcined in the calciner to produce clinker, and a clinker cooler connected to the front end of the cement kiln, a flammable gas piping that connects a tank in which a liquefied flammable gas is stored to one or more injection points that belong to a group consisting of the clinker cooler and a calciner extraction piping through which the extracted gas extracted from the clinker cooler flows toward the calciner, The flammable gas pipe is characterized in that it supplies the liquefied flammable gas or a flammable gas obtained by vaporizing the liquefied flammable gas while it is flowing to the injection point.

[0012] According to the inventor's extensive research, it has been confirmed that methane is more susceptible to combustion retardation than coal, which is the primary fuel used in cement production. The reason for this is that combustible gases such as methane do not contain fuel particles, unlike coal, and therefore oxygen and fuel do not mix as easily as with coal, which is thought to result in concerns about combustion retardation. In light of this, it is expected that further combustion retardation will occur when combustible gases such as ethane, propane, butane, and ammonia, which have slower combustion rates than methane, are used as fuel.

[0013] If combustion delays occur before the kiln in the cement manufacturing process, the clinker will not have the proper temperature history, which can have a negative impact on quality, such as an increase in free lime.Furthermore, this can lead to a decrease in cement production due to temperature limits in downstream equipment.

[0014] In the device for utilizing liquefied flammable gas according to the present invention, flammable gas is injected in liquid or vaporized form into one or more injection points that belong to a group consisting of a clinker cooler and a calciner extraction pipe through which the extracted gas extracted from the clinker cooler flows toward the calciner.

[0015] A clinker cooler installed in a cement manufacturing facility receives and cools cement clinker (hereinafter referred to as "clinker" where appropriate) that has been burned in a cement kiln. A clinker cooler typically cools the clinker by blowing in air at approximately room temperature, which exchanges heat with the clinker at 1000°C or higher (typically about 1350°C). Therefore, the clinker cooler contains air (atmospheric gas) whose temperature has increased due to heat exchange with the high-temperature clinker.

[0016] Therefore, when liquefied combustible gas is injected into the clinker cooler, the clinker cooler acts as a vaporizer, vaporizing it into combustible gas. Furthermore, when the combustible gas mixes with high-temperature air in the clinker cooler, it reaches its ignition point or higher and begins to burn. Once the combustible gas has started to burn, it flows from the clinker cooler into the front of the cement kiln and is used as part of the fuel for burning the cement raw materials. This reduces the risk of combustion delays in the cement kiln.

[0017] The liquefied flammable gas may be vaporized while flowing through the flammable gas piping, and in this case, the vaporized flammable gas is injected into the clinker cooler. This configuration also reduces the risk of combustion delay in the cement kiln for the same reasons as above.

[0018] A portion of the high-temperature atmospheric gas (air) in the clinker cooler is extracted through the extraction pipe. Depending on its temperature, the extracted gas (hereinafter referred to as "extracted gas") is sent to the calciner and used as combustion air in the calciner, or sent to the raw material process and used to dry the raw materials. In addition, a portion of the low-temperature atmosphere is released as exhaust gas.

[0019] The ambient temperature within the clinker cooler decreases as it approaches the outlet from which the clinker is discharged. Specifically, the space within the clinker cooler is divided into a first zone where the ambient temperature is in the range of 150°C to 300°C, a second zone where the ambient temperature is in the range of 250°C to 650°C, and a third zone where the ambient temperature is in the range of 600°C to 900°C. Typically, a portion of the atmosphere within the third zone is extracted through a calciner extraction pipe and sent to the calciner. A portion of the atmosphere within the second zone is extracted through a raw material drying extraction pipe and sent to the raw material process. A portion of the atmosphere within the first zone is extracted through an exhaust gas extraction pipe and discharged to the atmosphere (outside the system) through a chimney or the like.

[0020] In other words, the extracted gas extracted from the clinker cooler by the calciner extraction pipe and flowing toward the calciner is relatively hot. Therefore, even if liquefied flammable gas is injected into the calciner extraction pipe rather than the clinker cooler, the calciner extraction pipe functions as a vaporizer, and the flammable gas is vaporized in the calciner extraction pipe to become a flammable gas. Furthermore, in the calciner extraction pipe, the flammable gas is mixed with high-temperature air (extracted gas toward the calciner), causing the concentration of the flammable gas contained in the mixed gas to fall within the flammable range and reach a temperature above its ignition point, thereby initiating combustion. In particular, the calciner extraction pipe has a relatively long length, sometimes exceeding 100 meters. Therefore, the extracted gas (high-temperature air) and the flammable gas are sufficiently mixed before reaching the calciner, making it easy for combustion to begin.

[0021] The combustible gas that has started to burn flows into the calciner and is used as part of the fuel for calcining the cement raw materials in the calciner. As a result, the risk of combustion delay in the calciner and the cement kiln located downstream is reduced.

[0022] The liquefied flammable gas may be vaporized while flowing through the flammable gas piping, and the resulting flammable gas may be injected into the calciner extraction piping. Even with this configuration, for the same reasons as above, there is less concern about combustion delay in the calciner and the cement kiln.

[0023] According to the above configuration, the flammable gas piping is arranged so as to reach the clinker cooler or the calciner bleed piping, and the liquefied flammable gas is passed through the flammable gas piping and injected into the clinker cooler or the calciner bleed piping, thereby making it possible to vaporize and use the liquefied flammable gas at the cement manufacturing plant. This makes it possible to easily use the flammable gas as an alternative fuel in the cement manufacturing process, which is expected to contribute to reducing CO2 emissions.

[0024] A liquid pump may be used to transport the liquefied flammable gas from the tank to the flammable gas pipe. On the other hand, the flammable gas pipe does not need to be equipped with a blower to promote the flow of the gaseous flammable gas. The expansion pressure generated by the vaporization of the liquefied flammable gas during flow can act as a driving force for the gaseous flammable gas to flow through the flammable gas pipe.

[0025] The liquefied flammable gas may contain 70% by volume or more of one or more gases belonging to the group consisting of ammonia, methane, ethane, propane, and butane. Preferably, the liquefied flammable gas contains 70% by volume or more of ammonia.

[0026] The flammable gas piping is arranged so as to pass through either or both of the clinker cooler and the exhaust gas extraction piping through which the extracted gas extracted from the clinker cooler flows toward the discharge port, and the flammable gas obtained by vaporizing the liquefied flammable gas in a liquid state while flowing through the flammable gas piping may be supplied to the injection point.

[0027] According to the above configuration, the piping through which the liquefied flammable gas flows (the flammable gas piping) is arranged so as to pass through one or both of the clinker cooler and the exhaust gas extraction piping through which the extracted gas extracted from the clinker cooler flows. In other words, the flammable gas piping is arranged so as to pass through an area where a high-temperature atmosphere exists (hereinafter referred to as the "high-temperature area"). Therefore, while flowing through the flammable gas piping, the liquefied flammable gas passes through the area where a high-temperature atmosphere exists, and is thereby vaporized through heat exchange through the piping. The high-temperature area may be, for example, an area within a range of 150°C to 1000°C.

[0028] As a result, the combustible gas vaporized while flowing through the combustible gas piping is supplied to the clinker cooler or the calciner extraction piping, where it is mixed with high-temperature air and combusted. The combustible gas in the combustion state is then used as an alternative fuel for burning raw materials or for calcining raw materials in the cement kiln or calciner.

[0029] Note that flammable gases with high purity will not ignite regardless of temperature. In the case of ammonia, the flammable range is 15.5% by volume to 27% by volume, and if the purity exceeds 80% by volume, for example, it will not spontaneously ignite. Note that even for hydrogen, which is one of the flammable gases most likely to spontaneously ignite, the maximum flammable range is 75% by volume. For this reason, it is unlikely that flammable gas will spontaneously ignite while flowing through the flammable gas piping, regardless of the temperature range in the clinker cooler or extraction piping that the flammable gas passes through.

[0030] The liquefied flammable gas utilization device comprises: a burner attached to an end of the flammable gas pipe on the injection point side, for injecting the liquefied flammable gas in a gaseous state into the injection point; a primary air pipe that passes through one or both of the clinker cooler and the exhaust gas extraction pipe and is connected to the combustible gas pipe at a position upstream of the burner, The flammable gas pipe may be configured to introduce a mixed gas of the flammable gas and the primary air to the burner at a position downstream of the connection point with the primary air pipe.

[0031] According to the above configuration, the flammable gas is vaporized while flowing through the flammable gas pipe, and the gaseous flammable gas is injected from the injection point after joining with the primary air flowing through the primary air pipe. At this time, the primary air pipe is arranged to pass through one or both of the clinker cooler and the extraction pipe, so that the primary air flowing through the primary air pipe is heated and joins with the flammable gas. As a result, the flammable gas is injected from the injection point in a further preheated state, further improving combustibility at the injection point.

[0032] In this case, the concentration of flammable gas in the flammable gas piping decreases after the point where the primary air piping and the flammable gas piping join. As a result, depending on the flow rate of the primary air, the concentration of the flammable gas may fall within the flammable range. If this occurs, the mixture of flammable gas and primary air flowing through the flammable gas piping may burn, potentially damaging the piping.

[0033] For this reason, it is preferable to adjust the temperature of the mixed gas at the junction of the primary air pipe and the flammable gas pipe so that the gaseous flammable gas is at or below its ignition temperature. The temperature of the mixed gas can be adjusted, for example, by designing the primary air pipe so that it passes only through the first zone. Another method for adjusting the temperature is to design the primary air pipe so that it can pass through multiple zones (two or more of the first zone, second zone, and third zone) and adjust the flow rate of the flammable gas flowing through each zone using a valve or the like.

[0034] The flow rate of the primary air or the (liquefied) flammable gas may be adjusted so that the concentration of the flammable gas contained in the mixed gas in the flammable gas piping does not fall within the flammable range. In this case, it does not matter if the flammable gas exceeds its ignition temperature at the junction of the primary air piping and the flammable gas piping. The concentration of the flammable gas contained in the mixed gas can be adjusted by adjusting the flow rate of the primary air flowing through the primary air piping with a valve or by adjusting the flow rate of the liquefied flammable gas sent to the flammable gas piping with a liquid feed pump.

[0035] The liquefied flammable gas utilization device comprises: a burner having a plurality of ports, attached to an end of the flammable gas pipe on the injection location side, for injecting the flammable gas into the injection location through one or more of the ports; The burner may also be provided with a primary air pipe that is connected to one of the multiple ports provided in the burner, other than the port to which the flammable gas pipe is connected, via one or both of the clinker cooler and the exhaust gas extraction pipe.

[0036] In the above configuration, the primary air flowing through the primary air piping is sent to the burner in a heated state, and gaseous flammable gas is blown from the burner into the blowing point together with the heated primary air, further improving combustibility at the blowing point.

[0037] In this configuration, the heated primary air and the flammable gas are not mixed in the piping, so the possibility of the flammable gas burning while flowing through the piping is extremely low, even without adjusting the temperature or flow rate of the flammable gas.

[0038] The primary air flowing through the primary air piping may be atmospheric air, atmospheric gas in the clinker cooler, or bleed gas in the exhaust gas bleed piping.

[0039] When the atmospheric gas in the clinker cooler or the bleed gas in the exhaust gas bleed pipe is used as primary air, these gases contain fugitive dust, mainly derived from clinker. Because combustible gas contains almost no ash, it has a lower radiant heat transfer rate during combustion than coal, the main fuel. However, as described above, by injecting primary air containing fugitive dust into the injection point together with the combustible gas, the fugitive dust functions as a radiant heat transfer medium during combustion of the combustible gas, thereby contributing to stabilizing the combustion of the combustible gas.

[0040] On the other hand, when the atmospheric gas in the clinker cooler or the bleed gas in the exhaust gas bleed pipe is used as primary air, it is conceivable that the flow rate of the primary air may change over time due to the thinning of the primary air piping caused by scattered dust in some locations or the adhesion of scattered dust to the wall of the primary air piping. From this perspective, a dust collector for collecting scattered dust may be provided in the primary air piping. That is, the primary air piping may be equipped with a primary air blower that promotes the flow of one or both of the atmospheric gas in the clinker cooler and the bleed gas in the bleed pipe through the primary air piping, and a dust collector that collects scattered dust contained in the gas flowing through the primary air piping.

[0041] The scattered dust collected by the dust collector can be mixed with the clinker discharged from the clinker cooler, or with cement in the finishing process of cement production where gypsum, etc. is added, which is expected to reduce the cost of crushing clinker.

[0042] The present invention relates to a method for utilizing liquefied flammable gas in a cement manufacturing process in which cement raw materials are burned to produce a cement kiln, the method comprising: injecting liquefied flammable gas into a flammable gas pipe connected to one or more injection points that belong to a group consisting of the clinker cooler and a calciner extraction pipe through which the extracted gas extracted from the clinker cooler flows toward the calciner; and supplying the liquefied flammable gas or a flammable gas obtained by vaporizing the liquefied flammable gas while it is flowing to the blowing point.

[0043] Further, the cement manufacturing equipment according to the present invention includes: a calciner for calcining cement raw materials; a cement kiln that produces clinker by firing the cement raw materials calcined in the calciner; a clinker cooler connected to the front of the cement kiln; a tank in which the liquefied flammable gas is stored in a liquefied state, and a flammable gas piping that connects the tank to one or more injection points that belong to a group consisting of the clinker cooler and a calciner extraction piping through which the extracted gas extracted from the clinker cooler flows toward the calciner, The flammable gas pipe is characterized in that it supplies the liquefied flammable gas or a flammable gas obtained by vaporizing the liquefied flammable gas while it is flowing to the injection point. [Effects of the Invention]

[0044] According to the present invention, liquefied flammable gas can be vaporized and utilized in a cement manufacturing plant in a simple and inexpensive manner. [Brief explanation of the drawings]

[0045] [Figure 1] 1 is a conceptual diagram schematically illustrating a configuration example of a cement production facility according to a first embodiment. FIG. [Figure 2] FIG. 2 is a diagram schematically illustrating a portion of the cement manufacturing facility shown in FIG. 1. [Figure 3] 2 is a diagram schematically illustrating a part of the cement production facility of FIG. 1, and corresponds to a conceptual diagram schematically illustrating an example of the configuration of a device for utilizing liquefied flammable gas according to the first embodiment. FIG. [Figure 4] 10 is a diagram schematically illustrating a configuration example of a liquefied flammable gas utilization device according to a second embodiment. [Figure 5] 10 is a diagram schematically illustrating another configuration example of the liquefied flammable gas utilization device of the second embodiment. [Figure 6] 10 is a diagram schematically illustrating another configuration example of the liquefied flammable gas utilization device of the second embodiment. [Figure 7] 10 is a diagram schematically illustrating another configuration example of the liquefied flammable gas utilization device of the second embodiment. [Figure 8] 10 is a diagram schematically illustrating another configuration example of the liquefied flammable gas utilization device of the second embodiment. [Figure 9] 10 is a diagram schematically illustrating another configuration example of the liquefied flammable gas utilization device of the third embodiment. [Figure 10] 10 is a diagram schematically illustrating another configuration example of the liquefied flammable gas utilization device of the third embodiment. [Figure 11] 10 is a diagram schematically illustrating a configuration example of a liquefied flammable gas utilization device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0046] The device for utilizing liquefied flammable gas according to the present invention is a device that can be attached to a cement manufacturing facility that produces cement clinker (hereinafter abbreviated as "clinker") from cement raw materials. Hereinafter, embodiments of the device for utilizing liquefied flammable gas, the method for utilizing liquefied flammable gas, and the cement manufacturing facility according to the present invention will be described with reference to the drawings. Note that the following drawings are shown schematically, and the dimensional ratios in the drawings do not match the actual dimensional ratios. Furthermore, the dimensional ratios do not necessarily match between the drawings.

[0047] In each of the following figures, the flow of a fluid (gas or liquid) is shown schematically by a two-dot chain line.

[0048] [First embodiment] Fig. 1 is a conceptual diagram showing a schematic structure of a cement production facility according to a first embodiment. The cement production facility 1 includes a preheater 11 that preheats the cement raw material M1, a calciner 13 that calcines the cement raw material M1, a cement kiln 20 that produces clinker 3 by burning the cement raw material M1 calcined in the calciner 13, and a clinker cooler 30 that is connected to a kiln front section 20b of the cement kiln 20 and cools the produced clinker 3. As shown in Fig. 1, the calciner 13 is connected to the kiln end section 20a of the cement kiln 20.

[0049] In this embodiment, the cement manufacturing facility 1 is equipped with a flammable gas burner 55, and this flammable gas burner 55 is connected to a tank 51 in which a liquefied flammable gas 50a is stored in a liquid state via a flammable gas pipe 53. In the configuration example of Fig. 1, the flammable gas burner 55 injects the liquefied flammable gas 50a into the clinker cooler 30. In other words, in this embodiment, the clinker cooler 30 corresponds to the injection point of the liquefied flammable gas 50a.

[0050] A liquid feed pump 52 is provided in the flammable gas piping 53, and the liquefied flammable gas 50a stored in the tank 51 is sent to the flammable gas piping 53 by the pressure of the liquid feed pump 52. However, as long as the liquefied flammable gas 50a stored in the tank 51 can be sent to the flammable gas piping 53, the liquid feed pump 52 is not an essential element in the present invention.

[0051] The liquefied flammable gas 50a may be a gas containing 70% by volume or more of one or more gases belonging to the group consisting of ammonia, methane, ethane, propane, and butane. Typically, the liquefied flammable gas 50a is liquefied ammonia, liquefied methane (liquefied natural gas), liquefied propane (liquefied petroleum gas), or liquefied butane, and most typically, is liquefied ammonia.

[0052] The powder of raw material M1 supplied to the top of the preheater 11 flows downward. As raw material M1 moves through the preheater 11, it is preheated by high-temperature exhaust gas and sent to the calciner 13. The calciner 13 is equipped with a calciner burner 14 that uses pulverized coal or the like as its main fuel. In the calciner 13, raw material M1 is further preheated (calcined) by the high-temperature gas from the calciner burner 14 and the cement kiln 20, and CaCO3, the main component of limestone contained in raw material M1, is thermally decomposed (decarbonated) into CaO and CO2. The temperature of the powder of raw material M1 reaches approximately 750°C to 800°C.

[0053] The raw material M1 calcined in the calciner 13 enters the cement kiln 20 from the kiln end 20a side and moves while rolling toward the exit at the kiln front 20b side. The main burner 21 described above is installed on the kiln front 20b side. The main burner 21 supplies a main fuel such as pulverized coal and primary air 25 for firing to the cement kiln 20.

[0054] In the cement kiln 20, the raw material M1 is heated to about 1450°C to 1500°C to produce clinker 3. This clinker 3 is discharged to a clinker cooler 30 after its temperature drops to about 1300°C to 1350°C.

[0055] The clinker cooler 30 cools the clinker 3 with ambient air CA at room temperature (approximately 20°C to 30°C) sent in by a cooling fan (not shown). Typically, a plurality of plates are laid on the bottom surface of the clinker cooler 30 so that they can move back and forth. The clinker 3 is guided downstream (to the outlet side of the clinker cooler 30) by the back and forth movement of the plates. The temperature of the clinker 3 decreases as it approaches the outlet of the clinker cooler 30, and it is then discharged from the outlet and stored in a clinker silo (not shown).

[0056] In the clinker cooler 30, the cooling air CA exchanges heat with the high-temperature clinker 3. As a result, high-temperature air is generated in the clinker cooler 30. Part of this air is sent from the kiln front section 20b side into the cement kiln 20 and used as secondary air for combustion.

[0057] As described above, in the cement manufacturing equipment 1 of this embodiment, the liquefied combustible gas 50a is injected into the clinker cooler 30. Because the space inside the clinker cooler 30 is a high-temperature environment, when the liquefied combustible gas 50a is injected into the clinker cooler 30, the liquefied combustible gas 50a vaporizes in the clinker cooler 30 and changes into gaseous combustible gas 50b (see FIG. 3). Furthermore, the combustible gas 50b is mixed with the high-temperature air present in the clinker cooler 30, and reaches or exceeds its ignition point, thereby starting to burn. The combustible gas 50b that has started to burn is sent into the cement kiln 20 from the kiln front section 20b side together with the high-temperature air (secondary air) inside the clinker cooler 30.

[0058] That is, according to the cement manufacturing equipment 1 of this embodiment, the combustible gas 50b supplied together with secondary air from the clinker cooler 30, as well as the main fuel such as pulverized coal supplied from the main burner 21, can be used as fuel for burning the raw material M1 in the cement kiln 20. In other words, according to this cement manufacturing equipment 1, the amount of the main fuel can be reduced, while the combustible gas 50b, which has a lower CO2 emission intensity than coal, can be used as an auxiliary fuel, and therefore, an effect of reducing CO2 emissions during cement manufacturing can be expected.

[0059] Furthermore, since the combustible gas 50b is supplied into the cement kiln 20 in a state in which combustion has already begun, even when the combustible gas 50b is used as auxiliary fuel in the cement kiln 20, delay in combustion of the main fuel is unlikely to occur.

[0060] Fig. 2 is a diagram that schematically illustrates a portion of the cement production facility 1 of Fig. 1. However, for the sake of convenience, the flammable gas piping 53 is not shown in Fig. 2.

[0061] As described above, the temperature of the clinker 3 decreases toward the downstream side within the clinker cooler 30. Therefore, the temperature of the atmospheric gas within the clinker cooler 30 also decreases toward the downstream side. Typically, the internal space of the clinker cooler 30 has a first region 31 in which the atmospheric temperature is in the range of 150°C to 300°C, a second region 32 in which the atmospheric temperature is in the range of 250°C to 650°C, and a third region 33 in which the atmospheric temperature is in the range of 600°C to 900°C. Of the first region 31, second region 32, and third region 33, the first region 31 is closest to the outlet end of the clinker cooler 30, and the third region 33 is closest to the cement kiln 20.

[0062] Because the atmospheric gas in the clinker cooler 30 has a temperature distribution as described above, it is sent to different locations for use depending on its temperature in consideration of thermal efficiency. In the example of FIG. 2, a portion of the atmospheric gas present in the third zone 33 of the clinker cooler 30 is extracted through the calciner extraction pipe 43 and sent to the calciner 13, where it is used as part of the combustion air (see also FIG. 1). A portion of the atmospheric gas present in the second zone 32 of the clinker cooler 30 is extracted through the raw material drying extraction pipe 42 and sent to the raw material process, where it is used for drying the raw material M1 (see also FIG. 1). On the other hand, the atmospheric gas present in the first zone 31 of the clinker cooler 30 has a temperature in the range of 150°C to 300°C, and therefore has low utility value in terms of thermal efficiency, etc., and is therefore extracted through the exhaust gas extraction pipe 41 and then discharged to the atmosphere (outside the system) through a chimney or the like (see also FIG. 1).

[0063] Fig. 3 is a diagram schematically illustrating a portion of the cement production facility 1 of Fig. 1, and is depicted in the same manner as Fig. 2. However, for convenience of illustration, the gas extraction pipes (41, 42, 43) illustrated in Fig. 2 are omitted, while the flammable gas pipe 53 and the flammable gas burner 55 are illustrated.

[0064] As described above, in the cement manufacturing equipment 1 of this embodiment, the flammable gas burner 55 injects the liquefied flammable gas 50a in a liquid state into the clinker cooler 30. The injected liquefied flammable gas 50a is vaporized in the clinker cooler 30 and converted into flammable gas 50b, and is supplied into the cement kiln 20 from the kiln front section 20b side in a combustion-started state. In other words, the liquefied flammable gas 50a is preferably injected by the flammable gas burner 55 into a region in the clinker cooler 30 where the ambient temperature is equal to or higher than the ignition point of the flammable gas 50b.

[0065] For example, when the liquefied flammable gas 50a is ammonia, the ignition point of ammonia is approximately 650°C, so the flammable gas burner 55 preferably injects the liquefied flammable gas 50a into the third zone 33 or the second zone 32 of the clinker cooler 30, and more preferably into the third zone 33. Note that the ignition point of methane is also approximately the same as that of ammonia, so the same applies when the liquefied flammable gas 50a is methane. Since the ignition points of ethane, propane, or butane are 100°C or more lower than that of ammonia, even when the liquefied flammable gas 50a is one of these gases, combustion begins in the clinker cooler 30 by injecting the gas into the third zone 33 or the second zone 32 of the clinker cooler 30.

[0066] 3, the liquefied flammable gas 50a stored in the tank 51 is simply guided to the flammable gas piping 53 through the flammable gas piping 53, and the liquefied flammable gas 50a is blown in liquid form from the flammable gas piping 53 into the clinker cooler 30, whereby the liquefied flammable gas 50a can be vaporized and used in the cement production facility 1. Thus, the liquefied flammable gas 50a can be vaporized in the cement production facility 1 in a simple and inexpensive manner.

[0067] In this embodiment, the liquid delivery pump 52 that delivers the liquefied flammable gas 50a, the flammable gas piping 53 for circulating the liquefied flammable gas 50a, and the flammable gas burner 55 for injecting the liquefied flammable gas 50a that has been circulated through the flammable gas piping 53 into the clinker cooler 30 correspond to the liquefied flammable gas utilization device.

[0068] [Second embodiment] A second embodiment of the liquefied flammable gas utilization device, the liquefied flammable gas utilization method, and the cement production facility according to the present invention will be described below. Note that, with regard to the parts common to the first embodiment, the description will be simplified or omitted as appropriate.

[0069] 4 is a diagram that schematically illustrates the structure of the device for utilizing liquefied flammable gas of this embodiment, following the example of FIG. 2. This embodiment differs from the first embodiment in that the liquefied flammable gas 50a is vaporized while flowing through the flammable gas piping 53, and the gaseous flammable gas 50b is blown into the clinker cooler 30 from the flammable gas burner 55. Hereinafter, the liquefied flammable gas 50a in a liquid state before being vaporized will be simply referred to as "liquefied flammable gas 50a," and the gas obtained after the liquefied flammable gas 50a has been vaporized will be referred to as "flammable gas 50b."

[0070] In this embodiment, the flammable gas pipe 53 is arranged so that a portion thereof passes through a region where a high-temperature atmosphere exists (high-temperature region). Therefore, while flowing through the flammable gas pipe 53, the liquefied flammable gas 50a in a liquid state is vaporized by heat exchange through the wall of the flammable gas pipe 53, and becomes a gaseous flammable gas 50b. In the example shown in Fig. 4, the flammable gas pipe 53 is arranged so that a portion thereof passes through the clinker cooler 30. In other words, the region inside the clinker cooler 30 is the above-mentioned high-temperature region.

[0071] As described above, in the clinker cooler 30, the cooling air CA exchanges heat with the high-temperature clinker 3 (see FIG. 2), so the ambient temperature in the clinker cooler 30 becomes high. Since the flammable gas piping 53 is arranged to pass through an area having a high-temperature atmosphere, the liquefied flammable gas 50a is vaporized while flowing through the flammable gas piping 53.

[0072] In the example shown in FIG. 4, the flammable gas pipe 53 is arranged to pass through the first region 31, where the ambient temperature is in the range of 150°C to 300°C. As described above with reference to FIG. 2, the atmosphere in the first region 31 is extracted through the exhaust gas extraction pipe 41 and then discharged to the atmosphere (outside the system) through a chimney or the like. Therefore, according to the configuration shown in FIG. 4, the discharged thermal energy can be effectively utilized for vaporizing the liquefied flammable gas 50a in a liquid state. Note that, in the first embodiment, the liquefied flammable gas 50a in a liquid state is blown into the clinker cooler 30, and thus the latent heat of vaporization is consumed when the liquefied flammable gas 50a vaporizes in the clinker cooler 30. When the liquefied flammable gas 50a is vaporized, the flammable gas pipe 53 is cooled by the latent heat. However, since high-temperature hot air that has cooled the clinker 3 is constantly supplied to the high-temperature region, the heat source is not lost.

[0073] On the other hand, if the combustible gas piping 53 is routed through the clinker cooler 30 as in this embodiment, it is conceivable that the scattered dust contained in the atmosphere of the clinker cooler 30 will adhere to the wall of the combustible gas piping 53, causing a decrease in heat exchange efficiency over time. From the viewpoint of using the combustible gas 50b as combustion fuel in the cement kiln 20 while minimizing changes in combustion conditions over time, it can be said that a configuration in which the liquefied combustible gas 50a is injected into the clinker cooler 30 while remaining in liquid form is preferable.

[0074] When arranging the flammable gas piping 53 inside the clinker cooler 30, it is preferable to arrange it, for example, at a high vertical position, i.e., near the inner wall near the ceiling, so as not to obstruct the airflow of the atmosphere inside the clinker cooler 30. However, the present invention does not limit the location inside the clinker cooler 30 where the flammable gas piping 53 is to be installed.

[0075] As described above, the region of the flammable gas piping 53 that passes through the clinker cooler 30 is intended to exchange heat with the atmospheric gas (high-temperature air) in the clinker cooler 30. From this perspective, the flammable gas piping 53 installed in this region may be appropriately shaped to increase its surface area. The shape may be any shape, and examples thereof include a spiral shape, an uneven shape, etc.

[0076] (Variation) The liquefied flammable gas utilization device of this embodiment has various variations. Each variation will be described below. Note that each variation can be combined with each other.

[0077] <1> In FIG. 4 , the flammable gas pipe 53 is arranged so as to pass through the first region 31 of the clinker cooler 30 and then communicate with the flammable gas burner 55 via the outside of the clinker cooler 30. However, it is arbitrary which region of the clinker cooler 30 the flammable gas pipe 53 passes through. For example, the flammable gas pipe 53 may be arranged so as to pass through the second region 32 in addition to the first region 31. As another example, the flammable gas pipe 53 may be arranged so as to pass through the second region 32 of the clinker cooler 30 and then communicate with the flammable gas burner 55 via the outside of the clinker cooler 30. As yet another example, the flammable gas pipe 53 may be arranged so as to pass through the third region 33 of the clinker cooler 30 and then communicate with the flammable gas burner 55 via the outside of the clinker cooler 30.

[0078] If the flammable gas 50b has a high purity, the probability of it igniting is extremely low regardless of the temperature. For example, the flammable range of ammonia is 15.5% by volume to 27% by volume, and if the purity exceeds 80% by volume, it will not spontaneously ignite. Even for hydrogen, which is one of the flammable gases most likely to spontaneously ignite, the maximum flammable range is approximately 75% by volume. For this reason, it is unlikely that the flammable gas piping 53 will spontaneously ignite while the liquefied flammable gas (50a, 50b) in a liquid or gaseous state flows through it, regardless of the temperature region in the clinker cooler 30.

[0079] However, from the viewpoint of safety, when the flammable gas pipe 53 is routed through the clinker cooler 30, it is more preferable to route it through an area showing a temperature lower than the ignition point of the flammable gas 50b. For example, when the liquefied flammable gas 50a is ammonia, the ignition point of ammonia is approximately 650°C, so it is preferable to arrange the flammable gas pipe 53 so that it passes through one or both of the first area 31 and the second area 32 of the clinker cooler 30.

[0080] <2> As shown in Figure 5, the gaseous flammable gas 50b may be mixed with primary air 73 flowing through a primary air piping 72 and then blown in from an injection point (flammable gas burner 55).

[0081] The device for utilizing liquefied flammable gas shown in Fig. 5 includes a primary air blower 71, a primary air pipe 72 through which primary air 73 flows, and a valve 74 installed on the primary air pipe 72. The flammable gas pipe 53 is connected to the primary air pipe 72 at a position where it passes through a region (high temperature region 53a) within the clinker cooler 30 and then reaches the injection point. The primary air pipe 72 is provided so that a portion of it passes through a region within the clinker cooler 30. In other words, the primary air pipe 72 is provided so that it passes through the high temperature region 72a. The primary air pipe 72 is connected to the flammable gas pipe 53 at a position where it passes through a region (high temperature region 72a) within the clinker cooler 30 and then reaches the injection point.

[0082] According to the above configuration, the primary air 73 flowing through the primary air piping 72 is heated while passing through the high temperature region 72a, and then mixed with the combustible gas 50b flowing through the combustible gas piping 53. As a result, the combustible gas 50b is blown in in a preheated state, improving the combustion efficiency of the combustible gas 50b.

[0083] 5, the flammable gas 50b is mixed with the primary air 73 while flowing through the flammable gas piping 53. For this reason, the concentration of the flammable gas 50b contained in the mixed gas may fall within the flammable range, and in such a case, there is a concern that the flammable gas 50b may ignite while flowing through the flammable gas piping 53. In view of this, it is preferable that the piping paths of the flammable gas piping 53 and the primary air piping 72 are set in advance so that the gas temperature at the junction of the flammable gas piping 53 and the primary air piping 72 is below the ignition point of the flammable gas 50b.

[0084] Also, the valve 74 may be adjusted so that the concentration of the combustible gas 50b contained in the mixed gas does not fall within the flammable range.

[0085] As shown in Fig. 6, the combustible gas 50b and heated primary air 73 may be supplied to a common injection point (combustible gas burner 55) without being mixed. Specifically, the combustible gas burner 55 may have a plurality of ports, and the primary air pipe 72 may be connected to a port different from the port to which the combustible gas pipe 53 is connected. In this case, unlike the configuration shown in Fig. 5, there is very little risk of the combustible gas 50b igniting while flowing through the combustible gas pipe 53.

[0086] <3> In the configurations of Figures 5 and 6, atmospheric air is used as primary air 73, and the primary air piping 72 through which this primary air 73 flows is provided so as to pass through the clinker cooler 30. In contrast to this, as shown in Figure 7, atmospheric gas within the clinker cooler 30 may be used as the primary air 73. In this case as well, the primary air piping 72 passes through the clinker cooler 30, which is a high-temperature region, and then is led to the injection point (combustible gas burner 55).

[0087] The atmospheric gas in the clinker cooler 30 mainly contains fugitive dust derived from the clinker 3. The combustible gas 50b contains almost no ash, and therefore has a lower radiant heat transfer rate during combustion than coal, which is the main fuel. According to the configuration shown in Fig. 7, primary air 73 containing fugitive dust is injected into the injection point together with the combustible gas 50b, so that the fugitive dust functions as a radiant heat transfer medium during combustion of the combustible gas 50b, contributing to stabilizing the combustion of the combustible gas 50b.

[0088] 7, similarly to FIG. 6, the example shown in FIG. 7 shows a case where the flammable gas pipe 53 and the primary air pipe 72 are not connected, and the flammable gas 50b and the primary air 73 are blown in from the same flammable gas burner 55. In contrast to this, as shown in FIG. 5, both pipes (53, 72) may be connected, and a mixed gas formed by joining the flammable gas 50b and the primary air 73 may be blown in from the flammable gas burner 55. The same applies to FIG. 8 below.

[0089] <4> When the atmospheric gas in the clinker cooler 30 is used as the primary air 73, a dust collector 75 for collecting scattered dust contained in the extracted atmospheric gas may be provided on the path of the primary air piping 72 (see FIG. 8). The scattered dust collected by the dust collector 75 can be used, for example, to mix with the clinker 3 discharged from the clinker cooler 30, or to mix with cement in the finishing process of cement production where gypsum or the like is added.

[0090] <5> The combustible gas 50b flowing through the combustible gas piping 53 and the high-temperature primary air 73 flowing through the primary air piping 72 may be mixed by an ejector. The mixed gas is blown in through a combustible gas burner 55. The ejector can be operated by power from the vaporized and highly pressurized combustible gas 50b. When the atmospheric gas in the clinker cooler 30 is used as the primary air 73, a dust collector 75 may be provided as in FIG. 8 to prevent the ejector from being thinned by scattered dust contained in the extracted atmospheric gas.

[0091] <6> In this embodiment, the flammable gas 50b is sent to the flammable gas burner 55 through the flammable gas piping 53 by the liquid sending pressure of the liquid sending pump 52 and the vaporization expansion pressure generated when the liquefied flammable gas 50a is vaporized. However, the present invention does not exclude a configuration in which a blower such as a Roots blower is installed in the flammable gas piping 53 to ensure pressure for blowing the vaporized flammable gas 50b from the flammable gas burner 55.

[0092] 5 and 6, the primary air piping 72 passes through the region (high temperature region 53a) inside the clinker cooler 30, but it may pass through the inside of the extraction piping (41, 42, 43: see FIG. 2) for extracting atmospheric gas from the clinker cooler 30. This point is also related to the contents of the third embodiment, and will be described in the section about the third embodiment.

[0093] [Third embodiment] A third embodiment of the liquefied flammable gas utilization device, the liquefied flammable gas utilization method, and the cement production facility according to the present invention will be described below. Note that, with regard to the parts that are common to the parts already described in the above embodiments, the description will be simplified or omitted as appropriate.

[0094] Fig. 9 is a diagram that schematically illustrates the structure of the device for utilizing liquefied flammable gas of this embodiment, following Fig. 2. This embodiment differs from the second embodiment in that the area through which the flammable gas pipe 53 passes is not the inside of the clinker cooler 30, but the inside of the extraction pipe (here, the exhaust gas extraction pipe 41) for extracting the atmospheric gas from the clinker cooler 30.

[0095] As described above, the exhaust gas extraction pipe 41 is a pipe for extracting the atmospheric gas present in the first region 31 of the clinker cooler 30 and leading it to the outside of the system. In other words, the inside of the exhaust gas extraction pipe 41 contains air at a temperature similar to that of the atmosphere present in the first region 31 of the clinker cooler 30. Therefore, the internal space of the exhaust gas extraction pipe 41 corresponds to the high-temperature region 53a.

[0096] That is, in this embodiment, as in the second embodiment, the liquefied flammable gas 50a that has been delivered is vaporized into flammable gas 50b by passing through the high-temperature region 53a while flowing through the flammable gas piping 53. This flammable gas 50b flows through the flammable gas piping 53 and is supplied to the flammable gas burner 55, and is then blown into the clinker cooler 30.

[0097] In the example of Fig. 9, the flammable gas piping 53 passes through the inside of the exhaust gas extraction piping 41, but it may also pass through the inside of other extraction piping (raw material drying extraction piping 42, calciner extraction piping 43). Fig. 10 shows a configuration example in which the flammable gas piping 53 passes through the inside of the raw material drying extraction piping 42, following the example of Fig. 9.

[0098] As described above with reference to FIG. 2 , the bleed gas bled from the clinker cooler 30 through the calciner bleed air pipe 43 is sent to the calciner 13 and used as part of the combustion air. Furthermore, the bleed gas bled from the clinker cooler 30 through the raw material drying bleed air pipe 42 is sent to the raw material process and used as part of the drying air for the raw materials M1. When the flammable gas pipe 53 is routed through these bleed pipes (42, 43), the temperature of the bleed gas flowing through each bleed pipe (42, 43) may be slightly reduced due to heat exchange between the wall of the flammable gas pipe 53, through which the liquefied flammable gas 50a flows, and the atmosphere in the clinker cooler 30. On the other hand, the bleed gas flowing through the exhaust gas bleed pipe 41 is not used for combustion or drying and is discharged to the outside of the system. Therefore, when the combustible gas pipe 53 passes through the extraction pipe that extracts the atmospheric gas from the clinker cooler 30, it is particularly preferable that the combustible gas pipe 53 pass through the calciner extraction pipe 43.

[0099] The configuration of this embodiment can be appropriately combined with each of the configurations described above in the second embodiment.

[0100] 5 and 6, it has been described that the atmospheric air as the primary air 73 taken from the primary air blower 71 into the primary air piping 72 is heated while passing through the region (high-temperature region 53a) in the clinker cooler 30. However, similar to the flammable gas piping 53 of this embodiment, the primary air 73 in the primary air piping 72 may also be heated by passing through the extraction piping (41, 42, 43).

[0101] [Fourth embodiment] A fourth embodiment of the liquefied flammable gas utilization device, the liquefied flammable gas utilization method, and the cement production facility according to the present invention will be described below. Note that, with regard to the parts that are common to the parts already described in the above embodiments, the description will be simplified or omitted as appropriate.

[0102] 11 is a diagram schematically illustrating the structure of the device for utilizing liquefied flammable gas of this embodiment, following Figures 2 and 3. This embodiment differs from the first embodiment in that the flammable gas burner 55 is connected to the calciner bleed air piping 43 rather than the clinker cooler 30. That is, in the configuration shown in Figure 11, the flammable gas burner 55 injects liquefied flammable gas 50a in a liquid state into the calciner bleed air piping 43.

[0103] As described above with reference to Fig. 2, the calciner bleed pipe 43 bleeds the atmospheric gas (secondary air) in the third zone 33, which is relatively hot among the atmospheric gases in the clinker cooler 30, and leads it to the calciner 13. In the calciner 13, this high-temperature secondary air is used as part of the air for combustion of the main fuel.

[0104] Because extremely high-temperature bleed gas flows through the calciner bleed gas piping 43, when the liquefied flammable gas 50a is blown into the calciner bleed gas piping 43, the calciner bleed gas piping 43 functions as a vaporizer, and the liquefied flammable gas 50a is vaporized in the calciner bleed gas piping 43 to become flammable gas 50b. Furthermore, in the calciner bleed gas piping 43, the flammable gas 50b is mixed with high-temperature air heading toward the calciner 13, causing the concentration of the flammable gas 50b contained in the mixed gas to fall within the flammable range and reach a temperature above its ignition point, and the flammable gas 50b begins to burn. The flammable gas 50b flows into the calciner 13 in a combustion-started state and is used as part of the fuel when the raw material M1 is calcined in the calciner 13.

[0105] Therefore, according to the configuration of this embodiment, the combustible gas 50b can be used as part of the fuel in the calciner 13 while reducing concerns about combustion delay.

[0106] 11, the liquefied flammable gas 50a in a liquid state is injected into the calciner bleed gas piping 43. However, by appropriately adopting the configurations of the second to third embodiments, the liquefied flammable gas 50a may be vaporized while flowing through the flammable gas piping 53, and the resulting gaseous flammable gas 50b may be injected into the calciner bleed gas piping 43. [Explanation of symbols]

[0107] 1: Cement manufacturing facility 3: Clinker 11: Preheater 13: Calciner 14: Calciner burner 20: Cement kiln 20a: Bottom of the kiln 20b: Kiln front 21: Main burner 25: Primary air 30: Clinker cooler 31:First area 32:Second area 33:Third area 41: Exhaust gas extraction piping 42: Bleeding piping for drying raw materials 43: Extraction piping for calciner 50a: Liquefied flammable gas 50b: Gas produced by vaporization of liquefied flammable gas (flammable gas) 51: Tank 52: Liquid transfer pump 53: Flammable gas piping 53a: High temperature area 55: Combustible gas burner 71: Primary air blower 72: Primary air piping 72a: High temperature area 73: Primary air 74: Valve 75: Dust collector CA: Atmosphere M1: Cement raw material

Claims

1. A liquefied flammable gas utilization device that can be attached to a cement manufacturing facility that has a calciner that calcines cement raw materials, a cement kiln that produces clinker by burning the cement raw materials calcined in the calciner, and a clinker cooler that is connected to a kiln front of the cement kiln, a flammable gas piping that connects a tank storing a liquefied flammable gas with an injection point set in a specific region within the clinker cooler; the specific region is a region in the clinker cooler where the atmospheric temperature is in the range of 600°C to 900°C, and, when a raw material drying extraction air pipe for extracting a part of the atmospheric gas in the clinker cooler for drying the cement raw materials is connected to the clinker cooler, the specific region is a region closer to the cement kiln than a connection point between the raw material drying extraction air pipe and the clinker cooler, A device for utilizing liquefied flammable gas, characterized in that the flammable gas piping supplies the liquefied flammable gas or a flammable gas obtained by vaporizing the liquefied flammable gas during flow to the injection point.

2. 2. The device for utilizing liquefied flammable gas according to claim 1, wherein the flammable gas pipe is not provided with a blower for promoting the flow of the flammable gas.

3. 2. The device for utilizing liquefied flammable gas according to claim 1, wherein the flammable gas pipe supplies the liquefied flammable gas to the injection point.

4. 3. The device for utilizing liquefied flammable gas according to claim 1 or 2, characterized in that the flammable gas piping is arranged so as to pass through one or both of the clinker cooler and the exhaust gas extraction piping through which the extracted gas extracted from the clinker cooler flows toward the discharge port, and the flammable gas obtained by vaporizing the liquefied flammable gas in a liquid state while flowing through the flammable gas piping is supplied to the injection point.

5. The liquefied flammable gas utilization device described in claim 4, characterized in that the flammable gas piping passes through an area within the clinker cooler where the ambient temperature is within the range of 150°C to 1000°C.

6. a burner attached to an end of the flammable gas pipe on the injection point side, for injecting the liquefied flammable gas in a gaseous state into the injection point; a primary air pipe that passes through one or both of the clinker cooler and the exhaust gas extraction pipe and is connected to the combustible gas pipe at a position upstream of the burner, 6. A liquefied flammable gas utilization device as described in claim 4 or 5, characterized in that the flammable gas piping is configured to guide a mixed gas of the flammable gas and the primary air to the burner at a position downstream of the connection point with the primary air piping.

7. a burner having a plurality of ports, attached to an end of the flammable gas pipe on the injection location side, for injecting the flammable gas into the injection location through one or more of the ports; 6. The device for utilizing liquefied flammable gas as described in claim 4 or 5, characterized in that it comprises a primary air pipe that is connected to one of the plurality of ports provided in the burner, other than the port to which the flammable gas pipe is connected, via one or both of the clinker cooler and the exhaust gas extraction pipe.

8. 8. The device for utilizing liquefied flammable gas according to claim 6 or 7, characterized in that the primary air piping is configured so that one or both of the atmospheric gas in the clinker cooler and the extracted gas in the exhaust gas extraction piping flow toward the burner side.

9. 9. The device for utilizing liquefied flammable gas according to claim 8, characterized in that the primary air piping is provided with a primary air blower that promotes the flow of one or both of the atmospheric gas in the clinker cooler and the bleed gas in the exhaust gas bleed piping through the primary air piping, and a dust collector that recovers scattered dust contained in the gas flowing through the primary air piping.

10. A method for utilizing liquefied flammable gas in a cement manufacturing process for producing clinker using cement manufacturing equipment having a calciner for calcining cement raw materials, a cement kiln for burning the cement raw materials calcined in the calciner, and a clinker cooler connected to the front end of the cement kiln, comprising: Injecting liquefied flammable gas into a flammable gas pipe connected to an injection point set in a specific region within the clinker cooler; supplying the liquefied flammable gas or a flammable gas obtained by vaporizing the liquefied flammable gas during flow of the liquefied flammable gas to the blowing point; the specific region is a region within the clinker cooler where the ambient temperature is in the range of 600°C to 900°C, and, when a raw material drying extraction piping for extracting a portion of the ambient gas within the clinker cooler for drying the cement raw materials is connected to the clinker cooler, the specific region is a region closer to the cement kiln than a connection point between the raw material drying extraction piping and the clinker cooler.

11. The method for utilizing a liquefied flammable gas according to claim 10, characterized in that the liquefied flammable gas contains 70% by volume or more of one or more gases belonging to the group consisting of ammonia, methane, ethane, propane, and butane.

12. a calciner for calcining cement raw materials; a cement kiln that produces clinker by firing the cement raw materials calcined in the calciner; a clinker cooler connected to the front of the cement kiln; A tank in which liquefied flammable gas is stored in a liquefied state is provided, and a flammable gas pipe is provided which connects the tank to an injection point set in a specific region within the clinker cooler, the specific region is a region in the clinker cooler where the atmospheric temperature is in the range of 600°C to 900°C, and, when a raw material drying extraction air pipe for extracting a part of the atmospheric gas in the clinker cooler for drying the cement raw materials is connected to the clinker cooler, the specific region is a region closer to the cement kiln than a connection point between the raw material drying extraction air pipe and the clinker cooler, A cement manufacturing facility characterized in that the flammable gas piping supplies the liquefied flammable gas or a flammable gas obtained by vaporizing the liquefied flammable gas during flow to the injection point.

Images