CN206803784U - The recuperative heater of heat storage is removed based on flue gas - Google Patents

Abstract

The utility model discloses a kind of recuperative heater that heat storage is removed based on flue gas, the recuperative heater is stopping feeding that time of coal gas and air, the flue gas of second gas port is introduced into the first gas port, purging removing is carried out to the residual coal gas in heat storage and associated conduit.Remaining coal gas diffusion caused by recuperative heater does not commutate when switching flow of flue gas direction is among air, solving the problems, such as the problem of technical discharge of existing recuperative heater pernicious gas, serious pollution environment and the technical waste than more serious high-quality coal gas.

Description

Regenerative heating furnace based on flue gas removal regenerative body

technical field

The utility model belongs to the technical field of energy-saving and emission-reduction of regenerative heating furnaces, in particular to a regenerative heating furnace based on flue gas removal of regenerators.

Background technique

In the production of iron and steel industry and building materials industry, there are a large number of regenerative heating furnaces that undertake heavy material heating tasks. The regenerative heating furnace adopts reversing combustion technology to realize high-temperature waste heat recovery and high-temperature preheating of low calorific value gas. The biggest advantage of this technology is that it realizes high-temperature waste heat (smoke temperature as high as 1200 ℃) and high efficiency with a small footprint. At the same time, high-temperature preheating of low calorific value gas is realized (preheating temperature is as high as 900°C-1000°C). Taking steel rolling regenerative heating furnace as an example, steel rolling regenerative heating furnace generally uses blast furnace gas (CO content 20 %-30%) and converter gas (CO content 60%-80%), the principle of waste heat recovery from high-temperature flue gas: dozens of pairs of regenerators are symmetrically arranged on both sides of the heating furnace, when fuel and air flow from one side of the furnace (defined When it is injected into side A), fuel and air are preheated by the high-temperature regenerator on this side to above 900°C, and then enter the furnace of the heating furnace for combustion. Exhausted through the heat storage body, the high-temperature flue gas releases heat to the heat storage body when passing through the heat storage body on this side, and heats the heat storage body to a high temperature (the maximum temperature is above 1000°C). After running for a period of time (generally about 90s), the gas-flue gas flow direction is switched through the reversing valve, the fuel and air are injected from the B side of the furnace, and the flue gas is diverted from the A side outlet. The high-temperature preheating of low calorific value fuel and the efficient recovery of high-temperature flue gas waste heat are realized during non-stop switching.

However, this technology also has very serious technical defects. During the reversing process of the regenerative heating furnace, the regenerator on one side of the burner is switched to the flue gas discharge flue. This conversion will cause the regenerator on this side and The remaining gas in the pipeline between the reversing valve and the heat storage body is discharged into the atmosphere. Take rolling steel regenerative heating furnace as an example to illustrate the defects of this technology:

1) A large amount of toxic gas will be discharged into the atmosphere every time switching, resulting in very serious technical discharge of harmful gas (CO has high toxicity).

2) A certain amount of gas will be discharged into the atmosphere without burning every time switching, resulting in technical waste of high-quality gas fuel.

Taking a medium-sized heating furnace as an example, there are 80 pairs of regenerators in total. The volume of each pair of regenerators and related pipes is 0.3Nm ³ , and 24Nm ³ of gas will be released into the air every time the direction is changed, and there will be 7603200Nm ³ of gas per year. The coal gas is discharged into the atmosphere. According to the calorific value of 1000Kcal/Nm ³ , it is equivalent to 1086.4 tons of standard coal. According to the calculation of the CO content of 25%, 1900800Nm ³ of gas will be discharged into the atmosphere. The poisonous gas emitted by a heating furnace is equivalent to a 200 Each person in a medium-sized city with a population of 10,000 breathes 1 CO per year, and the pollution to the environment is shocking.

Utility model content

Aiming at the problem of gas discharge during the reversing process of the regenerative heating furnace in the prior art, the purpose of the utility model is to provide a regenerative heating furnace based on the removal of the regenerative body by flue gas.

The purpose of this utility model is achieved through the following technical solutions.

A regenerative heating furnace based on a flue gas removal regenerator, comprising: a furnace body, a first four-way reversing valve, a second four-way reversing valve, a first three-way reversing valve and a second three-way reversing valve A directional valve, a first opening and a second opening are formed on one side of the furnace body, a third opening and a fourth opening are formed on the other side of the furnace body, and the first opening communicates with a first pipeline , the second opening communicates with a second pipeline, the third opening communicates with a third pipeline, the fourth opening communicates with a fourth pipeline, and the first four-way reversing valve communicates with the The first pipeline, the third pipeline, the fifth pipeline and the sixth pipeline, so that the first pipeline communicates with one of the fifth pipeline and the sixth pipeline and the The third pipeline communicates with the other pipeline in the fifth pipeline and the sixth pipeline; the second four-way reversing valve communicates with the second pipeline, the fourth pipeline, and the seventh pipeline respectively pipeline and the eighth pipeline, so that the second pipeline communicates with one of the seventh pipeline and the eighth pipeline, and the fourth pipeline communicates with the seventh pipeline and the eighth pipeline. The other pipeline in the eighth pipeline is communicated; the first three-way reversing valve is respectively communicated with the air intake pipeline, the first blowing pipeline and the fifth pipeline, so that the fifth pipeline can It communicates with any one of the air inlet pipeline and the first blowing pipeline, wherein a first pressurizer is installed on the air inlet pipeline, and the other port of the first blowing pipeline is connected to The sixth pipeline is communicated, and a first blower fan is installed on the first blowing pipeline; the second three-way reversing valve is respectively communicated with the gas inlet pipeline, the second blowing pipeline and the seventh pipeline so that the seventh pipeline can communicate with any one of the gas inlet pipeline and the second blowing pipeline, wherein a second pressurizer is installed on the gas inlet pipeline, and the second The other port of the blowing pipeline communicates with the eighth pipeline, and a second fan is installed on the second blowing pipeline;

Heat accumulators are installed on the first opening, the second opening, the third opening and the fourth opening, so that the gas passing through the first opening, the second opening, the third opening and the fourth opening can respectively Heat accumulator through the corresponding opening.

In the above technical solution, a first induced draft fan is installed on the sixth pipeline between the first blowing pipeline and the first four-way reversing valve.

In the above technical solution, a second induced draft fan is installed on the eighth pipeline between the second blowing pipeline and the second four-way reversing valve.

In the above technical solution, the ports of the sixth pipeline and the eighth pipeline are respectively fixed with a chimney.

The method for using the above-mentioned regenerative heating furnace comprises the following steps:

1) Adjust the first three-way reversing valve and the second three-way reversing valve so that the fifth pipeline communicates with the air inlet pipeline, and the seventh pipeline communicates with the gas inlet pipeline connected;

2) Adjust the first four-way reversing valve so that the first pipeline communicates with the fifth pipeline, and the sixth pipeline communicates with the third pipeline; adjust the second four-way Through the reversing valve, the second pipeline communicates with the seventh pipeline, the fourth pipeline communicates with the eighth pipeline, and the first pressurizer and the second pressurizer are turned on, so that Coal gas and air are respectively fed into the corresponding gas inlet pipeline and air inlet pipeline;

3) Switch the flow direction of the flue gas (the flue gas is mixed with coal gas): stop the gas and air from passing into the corresponding gas inlet pipeline and air inlet pipeline respectively, and close the first pressurizer and the second pressurizer machine, adjust the first three-way reversing valve and the second three-way reversing valve, so that the fifth pipeline communicates with the first blowing pipeline, and the seventh pipeline communicates with the second blowing pipeline. The pipeline is connected; the first fan and the second fan are turned on, and after N seconds, the first fan and the second fan are turned off;

4) Adjust the first three-way reversing valve and the second three-way reversing valve so that the fifth pipeline communicates with the air inlet pipeline, and the seventh pipeline communicates with the gas inlet pipeline. connected; adjust the first four-way reversing valve so that the first pipeline communicates with the sixth pipeline, and the fifth pipeline communicates with the third pipeline; adjust the second four-way Through the reversing valve, the second pipeline communicates with the eighth pipeline, the fourth pipeline communicates with the seventh pipeline, and the first pressurizer and the second pressurizer are turned on, so that Coal gas and air are passed into corresponding gas inlet pipelines and air inlet pipelines respectively.

In the above technical solution, said N is less than or equal to 600 seconds.

Compared with the prior art, the beneficial effects of the regenerative heating furnace of the present utility model are:

When the regenerative heating furnace switches the flow direction of the flue gas, the residual gas is released into the atmosphere without reversing, which solves the problems of technical emission of harmful gases, serious environmental pollution and serious problem of high-quality gas in the existing regenerative heating furnace. Technical waste issues.

Description of drawings

Fig. 1 is the schematic diagram of the working state of the regenerative heating furnace of the present utility model;

Fig. 2 is a schematic diagram of the state when the regenerative heating furnace of the present invention is purged;

Fig. 3 is a schematic diagram of the working state of the regenerative heating furnace of the present invention after switching.

in,

1: Second opening 2: First opening 3: Furnace body 4: Flame

5: Fourth opening 6: Third opening 7: Second press

8: The second three-way reversing valve 9: Chimney 10: The second induced draft fan

11: The second four-way reversing valve 12: The first four-way reversing valve 13: The first induced draft fan

14: The first three-way reversing valve 15: The first pipeline 16: The first pressurizer

17: Second fan 18: First fan 19: Second pipeline

20: fifth pipeline 21: sixth pipeline 22: third pipeline

23: Seventh pipeline 24: Fourth pipeline 25: Eighth pipeline

26: Air inlet pipeline 27: First blowing pipeline 28: Gas inlet pipeline

29: the second blowing pipeline.

detailed description

In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right" etc. are all based on the orientation or positional relationship shown in the drawings, or It is the orientation or positional relationship that is usually placed when the utility model is used, and it is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and operation, and therefore cannot be construed as a limitation of the utility model. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

A method for removing reversing residual gas in a regenerator in a regenerative heating furnace and corresponding pipelines by using flue gas, comprising the following steps:

①The gas and combustion-supporting air are passed into the furnace body through the first gas port on the furnace body, the gas and air are burned in the furnace body to form flue gas, and the flue gas is discharged to the outside of the furnace body through the second gas port on the furnace body;

② Stop feeding gas and air into the furnace body, introduce the flue gas discharged from the second gas port into the furnace body from the first gas port, and keep it for N seconds, and N is less than or equal to 600 seconds; (at the moment when the gas and air supply is stopped , introduce the flue gas from the second gas port into the first gas port, and purge and remove the residual gas in the regenerator and related pipelines.)

Preferably, in step ②, the flue gas is introduced into the furnace body under pressure.

③Introduce gas and air into the furnace body again: make gas and air enter the furnace body through the second gas port, gas and air burn in the furnace body to form flue gas, and the flue gas is discharged to the outside of the furnace body through the first gas port on the furnace body;

Wherein, the number of the first air port is at least one, the number of the second air port is at least one, and heat storage bodies are installed on the first air port and the second air port.

After step ③, repeat steps ① to ③.

The above method can be realized by the regenerative heating furnace described below. As shown in Figures 1 to 3, it includes: a furnace body 3, a first four-way reversing valve 12, a second four-way reversing valve 11, a first three-way reversing valve 14 and a second three-way reversing valve 8, One side of the furnace body 3 is formed with a first opening 2 and a second opening 1 (equivalent to the first gas port in the method), and the other side of the furnace body 3 is formed with a third opening 6 and a fourth opening 5 (equivalent to method), the first opening 2 communicates with the first pipeline 15, the second opening 1 communicates with the second pipeline 19, the third opening 6 communicates with the third pipeline 22, and the fourth opening 5 communicates with the fourth The pipeline 24 and the first four-way reversing valve 12 communicate with the first pipeline 15, the third pipeline 22, the fifth pipeline 20 and the sixth pipeline 21, so that the first pipeline 15 and the fifth pipeline Road 20 communicates with one of the sixth pipelines 21 and the third pipeline 22 communicates with the other pipeline in the fifth pipeline 20 and the sixth pipeline 21; the second four-way reversing valve 11 The second pipeline 19, the fourth pipeline 24, the seventh pipeline 23 and the eighth pipeline 25 are connected respectively, so that the second pipeline 19 is connected with one of the seventh pipeline 23 and the eighth pipeline 25 The pipeline is connected and the fourth pipeline 24 is communicated with another pipeline in the seventh pipeline 23 and the eighth pipeline 25; Road 27 communicates with the fifth pipeline 20, so that the fifth pipeline 20 can communicate with any one of the air inlet pipeline 26 and the first blowing pipeline 27, wherein, the air inlet pipeline 26 is equipped with a The first pressurizer 16, another port of the first blowing pipeline 27 communicates with the sixth pipeline 21, and a first fan 18 is installed on the first blowing pipeline 27; the second three-way reversing valve 8 is respectively It is communicated with the gas inlet pipeline 28, the second blowing pipeline 29 and the seventh pipeline 23, so that the seventh pipeline 23 can communicate with any one of the gas inlet pipeline 28 and the second blowing pipeline 29, wherein , a second pressurizer 7 is installed on the gas inlet pipeline 28, another port of the second blowing pipeline 29 communicates with the eighth pipeline 25, and a second fan 17 is installed on the second blowing pipeline 29;

Heat accumulators are installed on the first opening 2, the second opening 1, the third opening 6 and the fourth opening 5, so that through the first opening 2, the second opening 1, the third opening 6 and the fourth opening 5 The gas can respectively pass through the regenerator of the corresponding opening.

Preferably, a first induced draft fan 13 is installed on the sixth pipeline 21 between the first blowing pipeline 27 and the first four-way reversing valve 12 .

Preferably, a second induced draft fan 10 is installed on the eighth pipeline 25 between the second blowing pipeline 29 and the second four-way reversing valve 11 .

Preferably, the ports of the sixth pipeline 21 and the eighth pipeline 25 are respectively equipped with a chimney 9 .

The use method of the above-mentioned regenerative heating furnace includes the following steps:

1) Adjust the first three-way reversing valve 14 and the second three-way reversing valve 8, so that the fifth pipeline 20 communicates with the air inlet pipeline 26, and the seventh pipeline 23 communicates with the gas inlet pipeline 28;

2) Adjust the first four-way reversing valve 12 so that the first pipeline 15 communicates with the fifth pipeline 20, and the sixth pipeline 21 communicates with the third pipeline 22; adjust the second four-way reversing valve 11 so that The second pipeline 19 is communicated with the seventh pipeline 23, the fourth pipeline 24 is communicated with the eighth pipeline 25, the first pressurizer 16 and the second pressurizer 7 are opened, and gas and air are respectively passed into corresponding Gas inlet pipeline 28 and air inlet pipeline 26;

3) Switch the flow direction of flue gas: stop gas and air from passing into the corresponding gas inlet pipeline 28 and air inlet pipeline 26 respectively, close the first pressurizer 16 and the second pressurizer 7, adjust the first three Through the reversing valve 14 and the second three-way reversing valve 8, the fifth pipeline 20 is communicated with the first blowing pipeline 27, and the seventh pipeline 23 is communicated with the second blowing pipeline 29; open the first fan 18 and The second fan 17 is kept for N seconds and then the first fan 18 and the second fan 17 are turned off; N is less than or equal to 600 seconds.

4) Adjust the first three-way reversing valve 14 and the second three-way reversing valve 8, so that the fifth pipeline 20 communicates with the air inlet pipeline 26, and the seventh pipeline 23 communicates with the gas inlet pipeline 28; A four-way reversing valve 12, so that the first pipeline 15 communicates with the sixth pipeline 21, and the fifth pipeline 20 communicates with the third pipeline 22; adjust the second four-way reversing valve 11, so that the second pipeline 19 is communicated with the eighth pipeline 25, the fourth pipeline 24 is communicated with the seventh pipeline 23, the first pressurizer 16 and the second pressurizer 7 are opened, and the gas and air are respectively passed into the corresponding gas inlet pipelines 28 and air intake line 26.

Repeat steps 1) to 4).

The technical scheme of the utility model is further described below in conjunction with specific embodiments.

As shown in Figure 1, at a certain moment, the left side of the regenerative heating furnace is the combustion side, and the gas and combustion-supporting air are injected from the first opening (intake gas) and the second opening (intake air) of the furnace hearth of the heating furnace, located at the first The regenerators of the opening and the second opening release heat to the gas and air to preheat the corresponding air and gas. The right side of the regenerative heating furnace is the flue gas discharge side, that is, the side of high-temperature flue gas waste heat recovery. The opening and the fourth opening lead out.

The position of the reversing valve at this time: the second three-way reversing valve 8 is in the gas connection position, and the second four-way reversing valve 11 is in a position where the second opening 1 can be connected to the gas, that is, the gas inlet pipeline 28 and the The seventh pipeline 23 communicates, and the seventh pipeline 23 communicates with the second pipeline 19 ; at this time, the fourth pipeline communicates with the eighth pipeline, so that the second induced draft fan 10 is connected with the fourth opening 5 . The first three-way reversing valve 14 is in the position connected to the air, and the first four-way reversing valve 12 is in the position connected with the first opening, that is, the air inlet pipeline communicates with the fifth pipeline, and the fifth pipeline 20 communicates with the fifth pipeline. The first pipeline 15 is connected; at this time, the sixth pipeline 21 is connected with the third pipeline 22, so that the first induced draft fan 13 is connected with the third opening.

Gas flow: After being pressurized by the second pressurizer 7, the gas enters the second three-way reversing valve 8, continues to flow through the second four-way reversing valve 11, and then enters the second opening 1 through the second pipeline 19 And through the regenerator at the second opening, the coal gas exchanges heat with the regenerator and heats up and is sprayed into the furnace body 3 for combustion to generate a flame 4 .

Combustion air flow: After being pressurized by the first pressurizer 16, the air enters the first three-way reversing valve 14, then flows through the first four-way reversing valve 12, and then enters the first opening 2 through the first pipeline 15 , and exchange heat with the regenerator at the first opening to raise the temperature, and then enter the furnace body 3 to support combustion.

Flue gas flow: coal gas and combustion-supporting air are combusted to form 4 flames, and the smoke formed by flame 4 flows out from the fourth opening 5 and the third opening respectively and passes through the heat storage body of the corresponding opening, and passes through the third pipeline and the fourth pipe respectively. and flow into the chimney 9 through the corresponding second four-way reversing valve 11 and first four-way reversing valve 12, and the power of flue gas flow comes from the second induced draft fan 10 and the first induced draft fan 13 respectively.

As shown in Figure 2, after the regenerative heating furnace works for a period of time, the combustion side and the flue gas discharge side need to be reversed, that is, the flue gas flow direction needs to be switched. When the reversing begins, the second three-way reversing valve 8 and the first three-way reversing valve 14 are respectively switched to the communication state with the second fan 17 and the first fan 18 at the same time, that is, the fifth pipeline and the first blowing pipeline communicated, and the seventh pipeline communicates with the second blowing pipeline. At this time, under the pressure of the second blower 17 and the first blower 18, the flue gas respectively pressurizes the residual gas accumulated in the regenerator at the second opening 1, the second four-way reversing valve 11 and its connecting pipeline, And the first four-way reversing valve 12, the regenerator at the first opening 2 and the residual air accumulated in the connecting pipeline are purged, and the gas and air entering the furnace body 3 after purging are completely burned in the furnace body.

As shown in Figure 3, at the moment when the residual gas is completely purged into the furnace, the second three-way reversing valve 8 is switched to the gas connection state, and the first three-way reversing valve 14 is switched to the air connection state, that is The fifth pipeline communicates with the air inlet pipeline, and the seventh pipeline communicates with the gas inlet pipeline. The second four-way reversing valve 11 and the first four-way reversing valve 12 switch to: the first pipeline communicates with the sixth pipeline, the fifth pipeline communicates with the third pipeline; the second pipeline communicates with the eighth pipeline The pipelines are connected, and the fourth pipeline is connected with the seventh pipeline. The regenerative heating furnace is switched to the state of combustion on the right side and exhaust gas on the left side, and the switching is completed. Generally speaking, the purge time should not exceed 3 seconds. After the switching is completed, the gas and air enter the furnace body through the third opening and the fourth opening for combustion, and the flue gas is discharged through the first opening and the second opening.

The utility model improves the structure of the original reversing system, and improves the control scheme of the reversing process, and uses the pulsed flue gas under pressure to perform pulse purge on the residual gas in the regenerator and related pipelines during the reversing.

1) Improve the structure of the reversing system

Before the gas and air enter the original reversing valve, the second three-way reversing valve and the first three-way reversing valve are newly installed respectively. The reversing valve realizes the flow switching between flue gas and air, and at the same time, a flue gas pulse fan-the first induced draft fan and the second induced draft fan are respectively arranged on the flue gas channel.

2) Improve the control scheme of the commutation process

The basic strategy after the improvement of the control scheme is: after the commutation starts, first cut off the gas and air supply on the left side of the furnace body, but keep the flue gas exhausted on the right side, then open the flue gas purging system, and use the pulse fan to extract the gas from the flue. The high-temperature flue gas purges the regenerators of the first opening and the second opening and the residual gas in the corresponding pipelines. After the purge is completed, the purge system is closed, and the right side of the furnace body is switched to the combustion state (gas and air are connected) ), the left side of the furnace body is switched to the smoke exhaust state. Note: The above "left" and "right" can be opposite sides or non-opposite sides.

The utility model has been described as an example above. It should be noted that, without departing from the core of the utility model, any simple deformation, modification or other equivalent replacements that can be made by those skilled in the art without costing creative labor all fall into the Into the scope of protection of the utility model.

Claims (4)

1. A regenerative heating furnace based on flue gas removal regenerator, it is characterized in that, comprises: furnace body (3), the first four-way reversing valve (12), the second four-way reversing valve (11 ), the first three-way reversing valve (14) and the second three-way reversing valve (8), a first opening (2) and a second opening (1) are formed on one side of the furnace body (3) , the other side of the furnace body (3) is formed with a third opening (6) and a fourth opening (5), the first opening (2) communicates with a first pipeline (15), and the second The opening (1) is communicated with a second pipeline (19), the third opening (6) is communicated with a third pipeline (22), and the fourth opening (5) is communicated with a fourth pipeline (24), The first four-way reversing valve (12) communicates with the first pipeline (15), the third pipeline (22), the fifth pipeline (20) and the sixth pipeline (21) respectively, so that The first pipeline (15) communicates with one of the fifth pipeline (20) and the sixth pipeline (21), and the third pipeline (22) communicates with the fifth pipeline Road (20) communicates with another pipeline in the sixth pipeline (21); the second four-way reversing valve (11) communicates with the second pipeline (19), the fourth pipeline ( 24), the seventh pipeline (23) and the eighth pipeline (25), so that the second pipeline (19) and the seventh pipeline (23) and the eighth pipeline (25) One pipeline communicates and the fourth pipeline (24) communicates with the other pipeline in the seventh pipeline (23) and the eighth pipeline (25); the first three-way reversing The valve (14) communicates with the air inlet pipeline (26), the first blowing pipeline (27) and the fifth pipeline (20) respectively, so that the fifth pipeline (20) can be connected with the air inlet pipeline Road (26) communicates with any one of the first blowing pipelines (27), wherein a first pressurizer (16) is installed on the air inlet pipeline (26), and the first blowing The other port of the pipeline (27) communicates with the sixth pipeline (21), and a first fan (18) is installed on the first blowing pipeline (27); The valve (8) is respectively communicated with the gas inlet pipeline (28), the second blowing pipeline (29) and the seventh pipeline (23), so that the seventh pipeline (23) can be connected with the gas inlet pipeline. The pipeline (28) is communicated with any one of the second blowing pipeline (29), wherein a second pressurizer (7) is installed on the gas inlet pipeline (28), and the second blowing pipe Another port of the road (29) communicates with the eighth pipeline (25), and a second fan (17) is installed on the second blowing pipeline (29); Heat accumulators are installed on the first opening (2), second opening (1), third opening (6) and fourth opening (5), so as to pass through the first opening (2), The gas in the second opening (1), the third opening (6) and the fourth opening (5) can respectively pass through the heat storage bodies of the corresponding openings. 2. The regenerative heating furnace according to claim 1, characterized in that the sixth pipeline between the first blowing pipeline (27) and the first four-way reversing valve (12) A first induced draft fan (13) is installed on (21). 3. The regenerative heating furnace according to claim 2, characterized in that the eighth pipeline between the second blowing pipeline (29) and the second four-way reversing valve (11) A second induced draft fan (10) is installed on (25). 4. The regenerative heating furnace according to claim 3, characterized in that a chimney (9) is installed at the ports of the sixth pipeline (21) and the eighth pipeline (25) respectively.