JPH04325593A - Apparatus for preventing high-temperature cwm feeding apparatus from causing drastic pressure rise - Google Patents

Abstract

PURPOSE:To prevent drastic pressure rise when operation is stopped by connecting a pressure-release pipe with a transfer pipe connecting a shut-off valve and a high pressure-receiving drum so as to be branched therefrom and providing a pressure-release drum on another end through a rupture disc. CONSTITUTION:When a heating fluid S at high temp. flows in a heater by mistake under a closed condition of an apparatus wherein operation is stopped and a shut-off valve 7 and a branched shut-off valve 7a are closed, expansion of CWM (a coal-water slurry) in the apparatus occurs by heating and the pressure in the apparatus is abnormally elevated. Then, about 10% of the expanded CWM passes through a pressure-release pipe 21 and breaks a rupture disc 22 to flash into a pressure-release drum 23. As the drum 23 is pressurized with nitrogen gas, water in the expanded CWM cannot be evaporated. Therefore, there is no possibility that clogging may occur in the apparatus caused by the elevation of the viscosity of the expanded CWM.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a high-temperature CW that heats CWM, which is a slurry of coal and water, and supplies it to an entrained bed gasifier.
Regarding the M supply device, especially the CW in the high temperature CWM supply device.
This invention relates to an overpressure prevention device for a high-temperature CWM supply device that prevents damage to the device by releasing the pressure when the pressure of M suddenly increases.

0002

2. Description of the Related Art Conventionally, an entrained bed gasifier is equipped with a high-temperature CWM supply device that heats and supplies CWM (coal-water slurry), which is a slurry of coal and water. This high temperature C
The WM supply device heats CWM that has been fluidized by mixing coal that has been pulverized to a particle size of 0.1 mm or less with water and supplies it to the spouted bed gasifier, as shown in Figure 3. C.W.
A CWM run tank a for storing M and this CWM
A charge pump b that pumps the CWM in the run tank a, a heater c that is connected to the downstream side of the charge pump b and that heats the CWM, and an entrained bed gasifier d that transfers the CWM heated by the heater c. It mainly consists of a transfer piping e for transferring to.

[0003] This spouted bed gasifier d reacts CWM supplied from a high-temperature CWM supply device with a gasifying agent such as oxygen and steam at high temperature to produce combustible gases such as hydrogen and carbon monoxide. The interior is pressurized to a high pressure of about 15 to 45 Kgf/cm2 to increase gasification processing capacity.

[0004] Also, the heater c heats the CWM passing through it with a heating fluid such as steam to a temperature in the range of 50 to 200°C to lower the viscosity of the CWM, and the CWM is transferred to the transfer pipe e.
The fluidity has been improved so that it can flow smoothly inside.

[0005] To explain the operating method of this high-temperature CWM supply device, first, at startup, the CWM turns on the heater c.
CWM of low concentration, that is, low viscosity with a small proportion of coal, is supplied to the spouted bed gasifier d side by a charge pump b so as not to clog the transfer pipe e. Then, after the internal pressure of the coal gasifier d rises to a predetermined pressure, a heating fluid such as steam starts flowing into the heater c, and the CWM passing through it is heated in the range of 50 to 200°C. Next, the proportion of coal will be gradually increased to increase the concentration so that the viscosity of the CWM does not exceed 1000 cp. Finally, when the supply of CWM is to be stopped, the proportion of coal in the CWM is reduced to lower the concentration, that is, the viscosity, and then the temperature of the heater c is lowered and the supply is stopped.

[0006] That is, C in this CWM lan tank a
WM is usually a mixture of 65 wt% coal and 35 wt% water, and its viscosity is approximately 1000 cp, but when the coal ratio increases by several wt%, the viscosity increases rapidly and fluidity decreases. This will cause the heater c and transfer pipe e to become clogged. On the other hand, increasing the proportion of water in order to reduce the viscosity of CWM has the contradictory drawback that the gasification efficiency of CWM in the spouted bed gasifier d decreases. Therefore, this high-temperature CWM supply device heats the CWM with a heating heater c, without increasing the proportion of water.
This suppresses the increase in the viscosity of the WM and prevents the highly concentrated CWM from clogging the heater c and the transfer pipe e.

By the way, in the above-mentioned high-temperature CWM supply system, if the internal pressure of the entrained bed gasifier d suddenly drops for some reason, the internal pressure of the heater c and the transfer pipe e also drops at the same time. As the water in the flowing CWM rapidly evaporates, the concentration of CWM increases and fluidity is lost, which clogs the heater c and the transfer pipe e, resulting in high temperature CWM.
The WM supply device sometimes became blocked. In this case, the high-temperature CWM supply device must be completely disassembled to remove the clogged CWM, or if that is not possible, the high-temperature CWM supply device must be rebuilt, resulting in a large loss. Therefore, the present inventors have proposed a new high-temperature CWM supply device to eliminate these disadvantages. As shown in Fig. 2, this new high-temperature CWM supply device is equipped with a high-pressure receiving drum f on the upstream side of the transfer pipe e of the conventional high-temperature CWM supply device to release the coal/water slurry upstream of the transfer pipe e. A cutoff valve g for blocking the flow of the coal/water slurry is provided on the downstream side of the transfer pipe e, and a nitrogen gas injection part h is further provided for injecting nitrogen gas into the transfer pipe e on the downstream side of the cutoff valve g. This is a new addition.

This shutoff valve g is designed to operate instantaneously to shut off the flow of coal/water slurry in the transfer pipe e when the pressure in the entrained bed gasifier d suddenly decreases. , the nitrogen gas injector h injects nitrogen gas into the transfer pipe e on the downstream side of the shutoff valve g at the same time as the shutoff valve g operates, and transfers the internal coal/water slurry to the entrained bed gasifier. d
It is designed to be pumped to the side. In addition, the high-pressure receiving drum f is controlled by nitrogen gas to approximately the same pressure as the inside of the transfer pipe e, and is connected to the transfer pipe e on the upstream side of the cutoff valve g, and a branch pipe n equipped with a branch cutoff valve m in the middle. It is connected to the. This branch cutoff valve m is linked to the above cutoff valve g, and opens instantaneously at the same time as the cutoff valve g closes to transfer the coal/water slurry in the transfer pipe e upstream of the cutoff valve g to the high pressure receiving drum f side. It is designed to flow.

That is, in this high-temperature CWM supply device, when the internal pressure of the entrained bed gasifier d suddenly decreases, the shutoff valve g
At the same time, the shutoff valve g is closed by the nitrogen gas injected from the nitrogen gas injection part h.
The high concentration coal/water slurry in the transfer pipe e on the downstream side of the shutoff valve g is all pumped to the entrained bed gasifier d side, and the high concentration coal/water slurry is in the transfer pipe e on the downstream side of the shutoff valve g. By preventing clogging and releasing all the high concentration coal/water slurry in the transfer pipe e and the heater c on the upstream side of the cutoff valve g to the high pressure receiving drum f, the transfer pipe on the upstream side of the cutoff valve g This prevents highly concentrated coal/water slurry from clogging inside the heater c and the heater c.

0010

[Problems to be Solved by the Invention] By the way, in the above-mentioned new high-temperature CWM supply equipment, the shutoff valve g is open during operation, and the pressure of the coal/water slurry inside the equipment is basically equal to that of the entrained bed gasifier. Since it is determined by the internal pressure of d, it will not rise abnormally. Additionally, if the viscosity of the coal/water slurry supplied from the CWM lantern a becomes abnormally high and the pressure at the outlet of the charge pump b rises abnormally, the rupture disk j of the CWM recovery path k will rupture, causing the high-pressure coal/water slurry to rupture. The equipment is protected by collecting the slurry into the CWM run tank.

However, if the heating fluid is accidentally flowed into the heater c when the operation is stopped and the shutoff valve g is closed, the moisture in the coal/water slurry inside the device will thermally expand and cause damage inside the device. There is a risk that the pressure will rise abnormally and destroy the device. In such cases, it is normal to install a safety valve in the equipment and release the slurry into the atmosphere. However, when hot coal/water slurry is released into the atmosphere, as mentioned above, the moisture evaporates rapidly and its viscosity increases. However, it gets stuck inside the device. In addition, this high-temperature coal/water slurry is transferred to the high-pressure receiving drum f.
It is also possible to release the high-pressure drum f to the inside, but since the equipment is stopped, this cannot be used unless the internal pressure of the high-pressure receiving drum f is equal to or higher than the specified pressure.

[0012] The present invention was devised to effectively solve these drawbacks, and its purpose is to prevent the coal/water slurry pressure in the equipment from increasing abnormally during operation stoppage. The present invention provides an overpressure prevention device for a high-temperature CWM supply device that protects the device by effectively releasing the heat.

[0013]

[Means for Solving the Problems] In order to achieve the above objects, the present invention provides a CWM run tank for storing a coal/water slurry containing a mixture of coal and water, and a CWM run tank which is provided in the CWM run tank to store coal/water slurry in the CWM run tank. A charge pump that pumps the water slurry, a heater connected downstream of the charge pump that heats the coal/water slurry, and a heated coal/water slurry transferred to the spouted bed gasifier. A high-pressure receiving drum is installed on the upstream side of the transfer piping to branch off from this to allow the coal/water slurry to escape, and a high-pressure receiving drum is installed on the downstream side of the transfer piping to block the flow of the coal/water slurry. In a high-temperature CWM supply device comprising a cutoff valve that is connected to the cutoff valve, and a nitrogen gas injector that is installed in a transfer pipe downstream of the cutoff valve and injects nitrogen gas into the transfer pipe, the cutoff valve and the high pressure receiving drum are connected. A pressure relief pipe is connected to the transfer pipe by branching from it, and a pressure relief drum is provided at the other end of the pressure relief pipe via a rupture disk.

[0014]

[Operation] Since the present invention is constructed as described above, when the shutoff valve closes at the time of operation stop and the inside of the equipment is in a closed state, the coal/water slurry inside the equipment is heated by the heating heater and the slurry is heated to a high temperature.
When the coal/water slurry becomes a high-pressure coal/water slurry and undergoes thermal expansion, and the pressure of the coal/water slurry inside the equipment rises abnormally, the rupture disk in the pressure relief piping ruptures and releases the high-temperature, high-pressure coal/water slurry into the pressure relief drum. He will be released to Therefore, accidents such as equipment damage due to high temperature and high pressure coal/water slurry and clogging of the coal/water slurry due to increased viscosity can be prevented.

[0015]

[Embodiment] An embodiment of the present invention will be described below.

FIG. 1 shows a high temperature CWM supply device equipped with an overpressure prevention device according to the present invention. As shown,
This high-temperature CWM supply equipment uses CWM (CWM) mixed with coal and water (
A CWM run tank 1 that stores a coal/water slurry), a charge pump 2 that pressurizes and transfers CWM in this CWM run tank 1, and a heater 3 that is connected to the downstream side of this charge pump 2 and heats the CWM. , a transfer pipe 5 that transfers the CWM heated by the heater 3 to the entrained bed gasifier 4, a high-pressure receiving drum 6 provided upstream of the transfer pipe 5 and branched from the transfer pipe 5, Piping 5
A shutoff valve 7 is provided on the downstream side of the CWM and shuts off the flow of CWM.
and a nitrogen gas injector 8 that injects nitrogen gas into the transfer pipe 5 downstream of the shutoff valve 7.

As mentioned above, this spouted bed gasifier 4 reacts CWM with a gasifying agent such as oxygen and water vapor at high temperature to produce combustible gases such as hydrogen and carbon monoxide. The internal capacity is 15-45K to increase processing capacity.
It is pressurized to a high pressure of about gf/cm2.

The charge pump 2 pressurizes the CWM in the CWM run tank 1 to a high pressure of about 30 Kgf/cm 2 and transfers it to the entrained bed gasifier 4 side via the heater 3 and the transfer pipe 5. Further, on the outlet side of the charge pump 2, a CWM recovery path 10 equipped with a rupture disk 9 is provided.
A rupture disk 9 is provided to protect the device when the viscosity of the CWM increases abnormally and the pressure at the outlet of the charge pump 2 exceeds a predetermined pressure.
M is collected again into CWM run tank 1.

Further, a heater 3 is provided downstream of the charge pump 2 via a check valve 11. This heater 3 allows the CWM pressure-fed from the charge pump 2 to pass through, and is heated by a heating fluid S such as water vapor.
CWM is heated in the range of 0 to 200°C to reduce its viscosity and improve its fluidity. The flow rate of this heating fluid S is controlled by a regulating valve 13 which is regulated by a thermometer 12 provided on the outlet side of the heater 3 . Further, the heating fluid S whose temperature has been lowered by heating the CWM becomes condensed water W and is discharged from the heater 3, and is heated again by a heating device (not shown) and becomes water vapor.
It is designed to be reused as a heating fluid S.

[0020] Also, the heater 3 and the spouted bed gasifier 4
The transfer pipe 5 that connects the CWM heated by the heater 3 to the entrained bed gasifier 4 side is provided with a shutoff valve 7 that instantly shuts off the flow of CWM flowing therethrough. . This shutoff valve 7 is controlled by a pressure gauge 4a that measures the pressure inside the spouted bed gasifier 4, and when the pressure inside the spouted bed gasifier 4 suddenly decreases, it is activated instantaneously and the transfer piping is closed. The flow of CWM within 5 is cut off. Further, a nitrogen gas injector 8 is provided in the transfer pipe 5 on the downstream side of the cutoff valve 7, and at the same time as the cutoff valve 7 operates, nitrogen gas is injected into the transfer pipe 5 on the downstream side of the cutoff valve 7. is injected to forcefully send the CWM inside to the spouted bed gasifier 4 side.

Further, one end of a branch pipe 5a is branched and connected to the transfer pipe 5 on the upstream side of the cutoff valve 7, and a high pressure receiving drum 6 is provided at the other end of the branch pipe 5a. That is, a branch cut-off valve 7a is provided in the middle of the branch pipe 5a, and opens instantly at the same time as the cut-off valve 7 closes in conjunction with the above-mentioned cut-off valve 7. And the CWM inside the heater 3 is made to flow to the high pressure receiving drum 6 side. The operating state of this branch cut-off valve 7a is opposite to that of the cut-off valve 7, and when the cut-off valve 7 is open in the normal state, it is closed, and prevents the CWM from flowing toward the high-pressure receiving drum 6. ing. The inside of this high-pressure receiving drum 6 is controlled to approximately the same pressure as the inside of the transfer pipe 5 by nitrogen gas, and the inside bottom is filled with cooling water for cooling the high-temperature CWM. That is, by maintaining the inside of the high-pressure receiving drum 6 at approximately the same pressure as the inside of the transfer pipe 5, when the branch cutoff valve 7a opens and the CWM flows to the high-pressure receiving drum 6 side, the saturated vapor pressure of the CWM decreases rapidly. The viscosity increases and fluidity is lost before flowing to the high-pressure receiving drum 6 side.
This prevents the water from flowing into the high-pressure receiving drum 6. In addition, a spray nozzle 1 is installed at the upper part of the high-pressure receiving drum 6.
4 is provided to inject cleaning water W' to supply cooling water into the high-pressure receiving drum 6, and to clean the inside of the high-pressure receiving drum 6 when discharging accumulated CWM. Further, the high-pressure receiving drum 6 is provided with a pressure gauge 16 together with a liquid level gauge 15, and the nitrogen gas valve 17 and exhaust valve 18 are controlled so that the pressure inside the high-pressure receiving drum 6 becomes a predetermined pressure. There is. Furthermore, a discharge port 19 is provided at the lowest part of the high-pressure receiving drum 6 for discharging the cooling water W' and the cooled CWM accumulated inside.

As shown in the figure, the overpressure prevention device 20 of this high temperature CWM supply device includes a pressure relief pipe 21 whose one end is connected to the transfer pipe 5 connecting the high pressure receiving drum 6 and the shutoff valve 7; It mainly consists of a rupture disk 22 provided in the middle of the pressure relief pipe 21 and a pressure relief drum 23 connected to the other end of the pressure relief pipe 21.

During normal operation, this rupture disk 22 serves as a barrier between the pressure relief drum 23 and the device, and if the pressure of the high-temperature CWM inside the device rises abnormally, it ruptures and releases the pressure of the high-temperature CWM to the drum 23 side. The rupture pressure is higher than that of the rupture disk 9 of the CWM recovery path 10. Further, the inside of the pressure relief drum 23 is pressurized to approximately the same pressure as the inside of the device by nitrogen gas etc. supplied from the pump 24, and its volume is determined by the heating temperature of the heater 3.
The volume is formed to have a certain margin for the maximum volume change of M. For example, assuming that water and coal have the same coefficient of thermal expansion, when CWM at 20°C is heated to 150°C, approximately 1
Since the volume expands by about 0%, if the volume of the transfer pipe 5 and heater 3 on the upstream side of the shutoff valve 7 is 1 m3, the volume of the pressure relief drum 23 is 0.1 to 0.2 m3.
It is enough.

Next, the operation of the present invention will be explained.

First, when performing normal operation of this high-temperature CWM supply device, as in the conventional case, at startup, the CWM is kept at room temperature and at a low concentration, that is, at a low concentration, in order to prevent the CWM from clogging the heater 3 and the transfer pipe 5. CWM having a low viscosity (approximately 60 wt%) is supplied to the spouted bed gasifier 4 side by a charge pump 2 under pressure of approximately 30 Kgf/cm2. Then, the internal pressure of the spouted bed gasifier 4 is, for example, about 2
When the operating state reaches approximately 0 Kgf/cm2, a heating fluid such as steam starts flowing through the heater 3, and the CWM passing through it is heated to, for example, about 150°C. Next, the concentration of CWM will be increased by gradually increasing the proportion of coal (approximately 65 wt%) such that the viscosity of CWM does not exceed 1000 cp. Finally, when stopping the supply of CWM, the proportion of coal in the CWM is reduced to the same level as at startup to lower the concentration, that is, the viscosity, and then the heating temperature by the heating heater 3 is lowered and stopped. It turns out.

However, if the internal pressure of the spouted bed gasifier 4 suddenly drops due to some reason, the pressure gauge 4a provided in the spouted bed gasifier 4 detects this and the shutoff valve is activated. 7 to shut off the transfer of CWM in the transfer pipe 5. Then, in conjunction with this, the nitrogen gas valve 8a of the nitrogen gas injector 8 operates, injecting high-pressure nitrogen gas into the transfer pipe 5 on the downstream side of the cutoff valve 7. All of the CWM is spouted into the spouted bed gasifier 4 before the moisture in the CWM in the gasifier 5 evaporates and its viscosity increases. Therefore, the viscosity of the CWM in the transfer pipe 5 on the downstream side of the shutoff valve 7 increases and the pipe is prevented from becoming clogged.

Furthermore, when the cutoff valve 7 is activated, the nitrogen gas valve 8a of the nitrogen gas injector 8 and the branch cutoff valve 7a of the branch pipe 5a are simultaneously activated and opened, and the high temperature CWM in the heater 3 and the transfer pipe 5 is shut off. It will be released to the high pressure receiving drum 6 side. Since the inside of this high-pressure receiving drum 6 is pressurized by nitrogen gas to approximately the same pressure as the inside of the apparatus, the saturated water vapor pressure in the high-temperature CWM received by this drum 6 does not decrease and the water does not evaporate rapidly. A decrease in the fluidity of the CWM is prevented, and the CWM flows smoothly into the high-pressure receiving drum 6. The high-temperature CWM flowing into the high-pressure receiving drum 6 is cooled down to room temperature by the cooling water spread inside the drum 6, and then discharged to the outside from the drain port 19 together with the cleaning water W' from the spray nozzle 14. become. Therefore, the high-temperature CWM in the transfer pipe 5 and heater 3 on the upstream side of the cutoff valve 7 smoothly flows into the high-pressure receiving drum 6 without a decrease in fluidity, so that it is not clogged therein. Then, similarly to the normal operation stoppage described above, after gradually reducing the proportion of coal in the CWM to lower the concentration, that is, the viscosity of the CWM, and stopping the heating temperature by the heating heater 3, the shutoff valve 7 and the branch The shutoff valve 7a will be closed and the operation will be stopped.

However, if the high-temperature heating fluid S accidentally flows into the heater 3 when the device is in a closed state with the operation stopped and the cutoff valve 7 and branch cutoff valve 7a closed, the CWM inside the device gets heated up. This causes thermal expansion, which causes the pressure inside the device to rise abnormally. For example, assuming that water and coal have the same coefficient of thermal expansion, a CWM at 20°C will expand by about 10% in volume when heated to 150°C. Then, approximately 10% of the thermally expanded CWM passes through the pressure relief piping 21 and destroys the rupture disk 22, causing the pressure relief drum 23 to collapse.
It will flash inside. Pressure relief drum 23
Since the interior of the CWM is pressurized with nitrogen gas as described above, the moisture in the thermally expanded CWM does not evaporate. Therefore, the viscosity of the thermally expanded CWM will not increase and the device will not become clogged.

As described above, in the present invention, in the unlikely event that the CWM undergoes thermal expansion and the inside of the device becomes high pressure, the overpressure prevention device 20 prevents this from occurring in the device or prevents the CWM from clogging inside the device. This makes it possible to prevent this from happening.

[0030]

[Effects of the Invention] In short, according to the present invention, if
The overpressure prevention device can prevent problems caused by thermal expansion of the CWM and high pressure inside the device, improving the reliability of the device and eliminating troublesome work such as disassembling and cleaning the device. This has excellent effects such as eliminating the need to perform the above process and reducing the cost and time cost of re-creating the device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a conventional high temperature CWM supply device.

FIG. 3 is a schematic diagram showing a conventional high temperature CWM supply device.

[Explanation of symbols]

1 CWM run tank 2 Charge pump 3 Heater 4 Entrained bed gasifier 5 Transfer piping 6 High pressure receiving drum 7 Shutoff valve 8 Nitrogen gas injection part 20 Overpressure prevention device 21 Pressure relief piping 22 Rupture Disc 23 Pressure relief drum

Claims (1)

[Claims] Claim 1: A CWM run tank that stores a coal/water slurry that is a mixture of coal and water, a charge pump installed in the CWM run tank and that pumps the coal/water slurry in the CWM run tank, and a charge pump downstream of the charge pump. a heater connected to the side and heating the coal-water slurry;
A transfer pipe that transfers the coal/water slurry heated by the heater to the entrained bed gasifier, and a high-pressure receiving drum that is provided upstream of the transfer pipe and branched from this and that releases the coal/water slurry. , installed on the downstream side of the above-mentioned transfer pipe, to carry coal and
In a high-temperature CWM supply device comprising a shutoff valve that shuts off the flow of water slurry, and a nitrogen gas injection section that is provided in a transfer pipe downstream of the shutoff valve and injects nitrogen gas into the transfer pipe, the cutoff valve A high-temperature CWM supply device characterized in that a pressure relief pipe is connected to a transfer pipe connecting the high-pressure receiving drum and the high-pressure receiving drum, and a pressure relief drum is provided at the other end of the pressure relief pipe via a rupture disk. overpressure protection device.