阅读说明：本技术 一种防止酸性气体回流的酸雾控制器 (Acid mist controller for preventing acid gas from refluxing ) 是由 郭静 季益龙 岳鑫先 于 2020-05-29 设计创作，主要内容包括：本发明涉及一种防止酸性气体回流的酸雾控制器,包括风机、主通路空气流量计、助燃空气流量计、煤气电磁阀、煤气针芯阀、点火变压器、硅油电伴热管、火焰检测器、点火棒、煤气手动阀、硅油储罐、硅油流量控制阀、燃烧室、酸雾控制器出口闸阀、阀门关到位装置以及关到位装置底座,所述风机连接主通路和助燃风通路,其中主通路上设置有主通路空气流量计和主通路空气电磁阀,助燃风通路上设置有助燃空气流量计和助燃空气电磁阀,主通路和助燃风通路的另一端连接燃烧室,点火棒通过螺纹孔固定在燃烧室的密封盖上；点火棒头部插入燃烧室内,尾部通过插头连接点火变压器出线；该方案能解决SO-(2)转化器内酸性过程气的回流损坏设备的问题。(The invention relates to an acid mist controller for preventing acid gas from flowing back, which comprises a fan, a main passage air flow meter, a combustion-supporting air flow meter, a gas electromagnetic valve, a gas needle core valve, an ignition transformer, a silicon oil electric heat tracing pipe, a flame detector, an ignition rod, a gas manual valve, a silicon oil storage tank, a silicon oil flow control valve, a combustion chamber, an acid mist controller outlet gate valve, a valve closing in-place device and a closing in-place device base, wherein the fan is connected with the main passage and a combustion-supporting air passage, the main passage air flow meter and the main passage air electromagnetic valve are arranged on the main passage, the combustion-supporting air passage is provided with the combustion-supporting air flow meter and the combustion-supporting air electromagnetic valve, the other ends of the main passage and the combustion-supporting air passage are connected with the combustion chamber, and the ignition rod is fixed on a sealing cover of the combustion chamber through threaded holes; the head part of the ignition rod is inserted into the combustion chamber, and the tail part of the ignition rod is connected with an outgoing line of the ignition transformer through a plug; the scheme can solve SO 2 Reflux loss of sour process gas in converterThe problem of bad equipment.)

1. An acid mist controller for preventing acid gas from flowing back is characterized by comprising a fan, a main passage air flow meter, a combustion-supporting air flow meter, a main passage air electromagnetic valve, a combustion-supporting air electromagnetic valve, a gas needle valve, an ignition transformer, a silicon oil electric heat tracing pipe, a flame detector, an ignition rod, a gas manual valve, a silicon oil storage tank, a silicon oil flow control valve, a combustion chamber, an acid mist controller outlet gate valve, a valve in-place closing device and a in-place closing device base, wherein the fan is connected with the main passage and the combustion-supporting air passage, the main passage is provided with a main passage air flow meter and a main passage air electromagnetic valve, the combustion-supporting air passage is provided with a combustion-supporting air flow meter and a combustion-supporting air electromagnetic valve, the other ends of the main passage and the combustion-supporting air passage are connected with a combustion chamber, and an ignition rod is fixed on a sealing cover of the combustion chamber through a threaded hole; the head part of the ignition rod is inserted into the combustion chamber, and the tail part of the ignition rod is connected with an outgoing line of the ignition transformer through a plug; the flame detector is fixed at the neck of the observation window through a hoop, wherein a detector probe is aligned with the glass sight glass; the gas pipeline is connected with the combustion chamber, wherein gas electromagnetic valves (6, 12) are arranged on the gas pipeline, a gas needle core valve is arranged at the end part of the gas pipeline, a silicon oil storage tank is connected with a combustion-supporting passage through a silicon oil pipeline and a silicon oil electric tracing pipe, an outlet gate valve of the acid mist controller is connected with the SO2 converter through a flange, the valve is closed in place, the valve is fixed on a base through a bottom angle bolt, and the base is fixed on the outlet pipeline of the acid mist controller through a hoop.

2. The acid mist controller for preventing acid gas from flowing back according to claim 1, wherein the valve closing position device comprises movable contacts (3-1, 3-2), fixed contacts (3-3, 3-4), contact leading-out wires (3-111, 3-222, 3-333, 3-444), a fixed base (3-5), a positioning screw (3-10), a tension spring (3-11), a lifting hook (3-12), a universal hook (3-13), a lifting hook (3-14), cable locking heads (3-15, 3-16), a shell (3-17), an outer support frame (3-18), a base (3-5), a shell (3-17) and an outer support frame (3-18) which are integrally formed, and a base is internally threaded, an internal thread is tapped at the bottom corner of the outer support frame; the supports (3-9) are divided into an upper layer, a middle layer and a lower layer, the lower layer of the supports is provided with a left support and a right support, and the supports are rectangular; the three layers of supports are provided with a plurality of holes, the upper layer of support and the lower layer of support are fixed on the base by flat head bolts and are used as fixed supports, wherein the two supports on the lower layer are provided with oblong grooves, and the positions of the supports on the lower layer in the vertical direction can be adjusted. The middle layer is a movable support. The upper layer bracket and the middle layer bracket are connected by two extension springs (3-11), two ends of each spring are respectively connected with metal buckles cast on the upper layer bracket and the middle layer bracket, the middle part of the middle layer bracket is slightly wide and thick and is provided with internal threads, the middle part of the bracket is connected with a lifting hook (3-12), and the lifting hook (3-12) is provided with external threads matched with the lifting hook and can be tightly connected with the middle layer bracket. The middle layer bracket can move up and down along with the hanging objects below the hanging hooks (3-12).

3. The acid mist controller for preventing acid gas from flowing back according to claim 2, wherein the fixing base (3-5), the bracket (3-9), the housing (3-17) and the outer bracket (3-18) are made of PC plastic, and the housing is cylindrical.

4. The acid mist controller for preventing acid gas from flowing back as claimed in claim 3, wherein two metal contacts (3-1, 3-2) are provided at both ends of the middle layer bracket as moving contacts; the two lower-layer supports are respectively provided with a metal contact (3-3, 3-4) as a static contact. The contacts (3-1, 3-3, 3-2 and 3-4) form two pairs of normally open contacts, 4 contacts are connected with 4 metal sheets (3-111, 3-222, 3-333 and 3-444) poured in respective brackets, the metal sheets are used as outgoing lines, the end part of the shell is provided with an opening for connecting a bolt, the outgoing line is connected with a cable and is respectively connected with a control loop and a signal loop, two sides of the shell (3-17) are provided with two openings, the cable enters from the outside through locking heads (3-15, 3-16), the lifting hook (3-13) is hung on the lifting hook (3-12) connected with the middle-layer bracket, the lifting hook (3-14) is hung under the universal hook (3-13), and the lifting hook (3-14) is welded on the top of the valve rod of the outlet valve of the acid mist controller.

5. The acid mist controller for preventing acid gas backflow according to claim 3 or 4, wherein the acid mist controller outlet pipeAdditionally arranging an SO on the road₃The gas detector (19), increase a hot-air pipe (20) on the outlet pipe, install an electric ball valve on the hot-air pipe and be used for controlling the hot-air break-make, hot-air temperature 340 ℃, pressure 6KPa, come from the outlet pipe of air heater, hot-air pipe one end is connected in the outlet pipe of air heater, the other end is connected to the pipeline behind the acid mist controller outlet valve, the connection method is trompil on the pipeline behind the outlet pipe of air heater and the acid mist controller outlet valve, then weld the hot-air pipe both ends respectively on the hole of division.

6. The acid mist controller for preventing acid gas from flowing back as claimed in claim 5, further comprising an air preheater for heating air at normal temperature to 340 ℃ to participate in impurity removal reaction of the WSA acid making process, wherein the structure of the acid mist controller comprises: the heater comprises two K-index thermocouples (5-1), an air inlet (5-2), an air outlet (5-3), a heating pipe (5-4), an air preheater shell (5-5), a wire inlet (5-6) and a connecting flange (5-7), wherein the two K-index thermocouples (5-1), the heating pipe (5-4), the wire inlet (5-6) and the connecting flange (5-7) are integrated to form an electric heater core, the air inlet (5-2), the air outlet (5-3) and the shell (5-4) are integrated to form a heater shell, the heater core and the heater shell are connected through the connecting flange (5-7) by bolts, normal temperature air enters from the inlet and is heated after absorbing heat from the heater core, and flows out through the outlet.

Technical Field

The invention relates to a controller, in particular to an acid mist controller for preventing acid gas from flowing back, and belongs to the technical field of coking equipment.

Background

The WSA acid making process can convert various sulfides in acid gas into concentrated sulfuric acid, and the specific steps are as follows: the method comprises the steps of using a K2CO3 solution as a desulfurizing agent, washing coke oven gas at normal pressure, absorbing acidic components such as H2S, HCN, CO2 and the like in the coke oven gas, resolving the acidic components under a vacuum condition to obtain acidic gas containing H2S, HCN, CO2 and the like, separating condensate and entrained impurities from the acidic gas by a mist catcher and a filter, and then feeding the acidic gas into an incinerator for combustion to generate gas containing SO 2. The gas enters an SO2 converter and is converted into SO3 under the action of an HTAS sulfuric acid catalyst on two catalytic beds, the converted gas is an acid-containing process gas (the main component is SO3), and the process gas is finally cooled to 290 ℃ from 524 ℃ through a cooler. The cooled process gas enters a vertical liquid film type glass tube in the WSA condenser from bottom to top, is cooled by normal temperature air blown into the glass tube from top to bottom, sulfuric acid with the concentration of about 98% is generated in the cooling process and is discharged into an acid pool at the bottom of the WSA condenser, and clean tail gas from which acid liquor is separated is finally discharged from a chimney. After condensation of the acid-containing process gas, the contained acid will be captured in the form of sulfuric acid, but the process gas will form acid mist during condensation in the WSA condenser, and since the acid mist cannot be completely separated from the process gas, the acid mist cannot be captured, and if not inhibited, the acid mist will be discharged from the chimney along with the process gas. In order to inhibit the formation of acid mist in the WSA condenser and completely separate the acid mist from the process gas, the acid mist controller can be started to capture the acid mist, and the acid mist emission of a chimney is reduced. The acid mist controller is similar to a small-sized incinerator, and the working flow is as follows: after the acid mist controller is started, the internal fan operates, the air duct electromagnetic valve is opened, air is blown into the combustion chamber, after about 20s, the ignition rod arranged on the cover plate of the combustion chamber is electrified to generate electric sparks, when the flame detector detects the electric spark, the gas electromagnetic valve is electrified, the gas enters the combustion chamber to be ignited, when the temperature of the airflow in the combustion chamber rises to 280 ℃, an operator controls the silicone oil flow electromagnetic valve in a central control mode to release the silicone oil, the silicone oil is mixed with combustion-supporting air and then enters the combustion chamber for combustion to generate airflow containing silicon dioxide particles, the airflow enters the SO2 converter from the outlet of the acid mist controller to be mixed with the acidic process gas, in the WSA condenser, the silica particles act as nuclei, so that the acid mist in the WSA condenser is adsorbed around the nuclei to form small acid droplets, and the small acid droplets can be completely separated from the process gas after continuously adsorbing the surrounding acid mist and gradually becoming larger. The outlet of the acid mist controller is provided with a gate valve, and the airflow of the silicon dioxide particles enters the SO2 converter through the gate valve of the outlet to be mixed with the acid process gas. The acid mist controller will typically be in three states: running state, fault vehicle-jumping state and cold standby state. In the operating state, the gate valve of the outlet should be open, and in the other two cases, the gate valve of the outlet should be closed, which will now be described separately with respect to the three states.

In the operating state: before the equipment is started and operated, an operator is required to open a gate valve firstly and then start an acid mist controller, a fan in the acid mist controller starts to operate, air is blown into a combustion chamber to be mixed and combusted with coal gas and silicon oil, and combusted airflow containing silicon oil particles enters an SO2 converter through an outlet gate valve to be mixed with acid process gas; when the vehicle is in a fault vehicle jumping state: once the equipment jumps, the burning flame can extinguish in the twinkling of an eye, and the solenoid valve in fan wind channel can cut off immediately, and the fan also stops work immediately. The wind pressure provided by the fan is 26Kpa, the wind pressure disappears after the fan is shut down, the pressure of the acid process gas in the SO2 converter is about 1.8Kpa, and at the moment, an operator needs to timely go to the site to close the gate valve at the outlet of the acid mist controller; otherwise, the acidic process gas in the SO2 converter flows backwards into the acid mist controller from the gate valve at the outlet, the temperature of the acidic process gas is 320 ℃, and after the acidic process gas is condensed, the formed acid liquid can corrode elements in the acid mist controller. In the cold standby state: the acid mist controller is in a shutdown standby state, the outlet gate valve is closed, otherwise the acid process gas in the SO2 converter flows back from the outlet gate valve to the corrosion element in the acid mist controller, similar to the situation of the fault trip state and the situation of the unclosed outlet valve. But the following problems exist for the two states of fault vehicle jumping and cold standby:

when the acid mist controller breaks down and jumps, the gate valve at the outlet needs to be closed immediately, and if an operator happens to patrol in the area at the moment, the operator can immediately arrive at the site to close the gate valve at the outlet of the acid mist controller; if no one is patrolled in the area, an operator needs to drive the central control room to the site to close the outlet gate valve of the acid mist controller, during the period, the acidic process gas in the SO2 converter leaks into the acid mist controller along the outlet pipe, and after the acidic process gas is condensed into acid liquor, the acidic process gas corrodes elements in the acid mist controller and damages equipment.

In the case when the acid mist controller is off standby. However, in the outlet gate valve, the temperature difference between the medium inside and outside the gate plate (the inside is the side connected with the acid mist controller, and the outside is the side connected with the SO2 converter) is large, the medium near the SO2 converter is a high-temperature acidic process gas at 320 ℃, and the medium near the acid mist controller is normal-temperature air, SO that the acidic process gas can be condensed into acid liquor after contacting the gate valve, the acid liquor is high-temperature and high-concentration sulfuric acid, and is always accumulated at the gate valve, SO that the gate valve is gradually corroded, the sealing performance and the cutting-off function of the valve are reduced, and the acidic process gas in the SO2 converter leaks into the acid mist controller body, and the equipment is damaged. The above problems are solved by a new technical method.

Disclosure of Invention

The invention provides an acid mist controller for preventing acid gas from flowing back, aiming at the problems in the prior art, the technical scheme is that a path of hot air is introduced after an outlet gate valve of the acid mist controller, the hot air is blown into an SO2 converter, the pressure of the hot air is required to be higher than that of acid process gas in the converter, otherwise, the hot air cannot be blown into the SO2 converter; the temperature of the hot air is not lower than the temperature of the process gas, otherwise, a large amount of condensation of the acidic process gas can be caused, the method is simple and easy to implement, and the problem that the equipment is damaged by the backflow of the acidic process gas in the SO2 converter can be solved.

In order to achieve the above object, the technical solution of the present invention is that, an acid mist controller for preventing acid gas from flowing back, the controller comprises a fan, a main passage air flow meter, a combustion-supporting air flow meter, a main passage air electromagnetic valve, a combustion-supporting air electromagnetic valve, a gas needle core valve, an ignition transformer, a silicone oil electric heat tracing pipe, a flame detector, an ignition rod, a gas manual valve, a silicone oil storage tank, a silicone oil flow control valve, a combustion chamber, an outlet gate valve of an acid mist controller, a valve in-place closing device and a base of the in-place closing device, wherein the fan is connected with the main passage and a combustion-supporting air passage, the main passage is provided with a main passage air flow meter and a main passage air electromagnetic valve, the combustion-supporting air passage is provided with a combustion-supporting air flow meter and a combustion-supporting air electromagnetic valve, the other ends of the main passage and the combustion-supporting air passage are connected with a combustion chamber, and an ignition rod is fixed on a sealing cover of the combustion chamber through a threaded hole; the head part of the ignition rod is inserted into the combustion chamber, and the tail part of the ignition rod is connected with an outgoing line of the ignition transformer through a plug; the flame detector is fixed on the neck of an observation window (glass sight glass) through a hoop, wherein a detector probe is aligned with the glass sight glass; the gas pipeline is connected with the combustion chamber, a gas electromagnetic valve is arranged on the gas pipeline, a gas needle core valve is arranged at the end part of the gas pipeline, a silicon oil storage tank is connected with a combustion-supporting passage through a silicon oil pipeline and a silicon oil electric heat tracing pipe, an outlet gate valve of the acid mist controller is connected with the SO2 converter through a flange, the valve is closed in place, the valve is fixed on a base through a bottom angle bolt, and the base is fixed on the outlet pipeline of the acid mist controller through a hoop.

As an improvement of the invention, the valve closing in-place device comprises a moving contact, a fixed contact, a contact leading-out wire, a fixed base and a positioning screw rod; an extension spring; a hook; a universal hook; a hook; a cable locking head; a shell and an outer support frame. The fixed base support, the shell and the outer support frame are made of PC plastic, and the shell is cylindrical. The base, the shell and the outer support frame are integrally manufactured, internal threads are tapped on the base, and internal threads are tapped at the bottom corner of the outer support frame; the support is divided into an upper layer, a middle layer and a lower layer, the lower layer of the support is provided with a left support and a right support, and the supports are rectangular; the three layers of supports are provided with a plurality of holes, the upper layer of support and the lower layer of support are fixed on the base by flat head bolts and are used as fixed supports, wherein the two supports on the lower layer are provided with oblong grooves, and the positions of the supports on the lower layer in the vertical direction can be adjusted. The middle layer is a movable support. The upper layer bracket and the middle layer bracket are connected by two extension springs, and two ends of each spring are respectively connected with metal buckles poured on the upper layer bracket and the middle layer bracket. The middle part of the middle layer bracket is slightly wide and thick and is provided with internal threads, the middle part of the bracket is connected with a lifting hook, and the lifting hook is provided with external threads matched with the lifting hook and can be tightly connected with the middle layer bracket. The middle layer bracket can move up and down along with the hanging object below the hanging hook. In order to ensure that the middle layer bracket moves in the vertical direction and does not shake in the horizontal direction, the three layers of brackets are fixed by two positioning screws.

As an improvement of the invention, two metal contacts are arranged at two ends of the middle layer bracket as moving contacts; the two lower-layer supports are respectively provided with a metal contact as a static contact. Two pairs of normally open contacts are constituteed to four contacts, 4 contacts all are connected with 4 sheetmetals 4 of pouring in the support separately, the sheetmetal will be as the lead-out wire, its tip has the trompil, for connecting bolt, the lead-out wire will with cable junction, access control circuit and signal circuit respectively, there are two trompils on the both sides of shell, the cable passes through locking head and gets into from the outside, link to each other with the lead-out wire, hang the universal hook on the lifting hook that links to each other with middle level support, hang the lifting hook below the universal hook, the lifting hook welding is at acid mist controller outlet valve rod top.

As an improvement of the invention, an SO3 gas detector is additionally arranged on an outlet pipeline of the acid mist controller, a hot air pipe is additionally arranged on the outlet pipeline, an electric ball valve is arranged on the hot air pipe to control the on-off of hot air, the temperature of the hot air is 340 ℃, the pressure of the hot air is 6KPa, the hot air pipe comes from an outlet pipe of the air preheater, one end of the hot air pipe is connected to the outlet pipe of the air preheater, the other end of the hot air pipe is connected to a pipeline behind an outlet valve of the acid mist controller, the connection method is that holes are formed in the outlet pipe of the air preheater and the pipeline behind the outlet valve of the acid mist controller, and then two ends of the hot air pipe are respectively welded to the opened holes. The pressure of the acid process gas is 1.8KPa, and the temperature is 280-320 ℃. The pressure and temperature of the hot air are both greater than the acid process gas. An electric ball valve is additionally arranged on the hot air pipe and is connected to the pipeline through a flange. The control logic of the electric ball valve is as follows: the added SO3 gas detector is connected with a control loop in series by taking a pair of normally open points S10, when the SO3 gas is detected to flow back into the acid mist controller, the detector gives a signal, and the normally open point S10 connected in series with the control loop is closed to participate in control. A pair of normally open points S20 are arranged in the valve closing in-place device and are connected in series into a control loop, and when an outlet valve of the acid mist controller is closed in place, a normally open contact S20 of the valve closing in-place device is closed to participate in control. When the trouble jumps the car, if the operating personnel can't arrive the scene in the short time and in time close the exit gate valve, in order to prevent that a large amount of acid process gas from flowing back and getting into the acid mist controller, increase a pair of relay normally open contact S30, can be operated by well accuse personnel, control electric ball valve and open. A pair of normally closed points SS of the relay is connected in series into a control loop, so that an operator can close the electric ball valve at any time. A pair of normally-open points KM1 of the electric ball valve is taken as a signal and uploaded to a central control room, and an operator is informed of the action condition of the electric ball valve. And taking a normally open point S21 of the valve closing in-place device as a signal, uploading the signal to a central control room, and informing an operator that the valve is closed in place.

As an improvement of the invention, the controller also comprises an air preheater, the air preheater heats the air at the normal temperature to 340 ℃, and the air preheater participates in the impurity removal reaction of the WSA acid making process, and the structure of the controller comprises: two K graduation number thermocouples, air intlet, air outlet, heating tube, air heater shell, inlet wire and flange, two K graduation number thermocouples, heating tube, inlet wire and flange are a whole, constitute the electric heater core, and air intlet, air outlet and shell are a whole, constitute the heater shell, pass through flange between heater core and the heater shell, with bolted connection, normal atmospheric temperature air is got into by the import, is heated after the heat absorption from the heating core, flows through the export.

Compared with the prior art, the acid mist controller has the advantages that hot air is introduced in the technical scheme, so that once corrosion leakage of the leakage outlet valve is prevented remotely when acid process gas is prevented from being condensed and corrosion equipment operators are absent, the hot air valve is automatically opened for purging to prevent the acid process gas from entering the acid mist controller, and meanwhile, an alarm signal is given.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an acid mist controller;

FIG. 2 is a diagram showing the connection between the acid mist controller and the SO2 converter;

FIG. 3 is a block diagram of the valve in-place closing apparatus of the acid mist controller;

FIG. 4 shows the base and the hoop of the valve closing-in-place device;

FIG. 5 is a schematic view of an air preheater;

FIG. 6 is a schematic view of an additional hot air pipe and an electric ball valve;

fig. 7 is a control schematic diagram of the electric ball valve.

The specific implementation mode is as follows:

for the purpose of enhancing an understanding of the present invention, the present embodiment will be described in detail below with reference to the accompanying drawings.

Example 1: referring to fig. 1, an acid mist controller for preventing acid gas from flowing back comprises a fan 1, a main passage air flow meter 2, a combustion-supporting air flow meter 3, a main passage air electromagnetic valve 4, a combustion-supporting air electromagnetic valve 5, a gas electromagnetic valve 6, a gas needle core valve 7, an ignition transformer 8, a silicon oil electric heat tracing pipe 9, a flame detector 10, an ignition rod 11, a gas manual valve 12, a silicon oil storage tank 13, a silicon oil flow control valve 14, a combustion chamber 15, an acid mist controller outlet gate valve 16, a valve closing in-place device 17 and a closing in-place device base 18, wherein the fan 1 is connected with a main passage and a combustion-supporting air passage, the main passage air flow meter 2 and the main passage air electromagnetic valve 4 are arranged on the main passage, the combustion-supporting air passage is provided with the combustion-supporting air flow meter 3 and the combustion-supporting air electromagnetic valve 5, and the other ends of the main passage and the combustion-supporting air passage are connected with the combustion chamber 15, the ignition rod 11 is fixed on a sealing cover of the combustion chamber through a threaded hole; the head part of the ignition rod is inserted into the combustion chamber, and the tail part of the ignition rod is connected with an outgoing line of the ignition transformer through a plug; the flame detector 10 is fixed at the neck of the observation window (glass sight glass) by a hoop, wherein the detector probe is aligned with the glass sight glass; the gas pipeline is connected with the combustion chamber, wherein gas electromagnetic valves 6 and 12 are arranged on the gas pipeline, a gas needle core valve 7 is arranged at the end part of the gas pipeline, a silicon oil storage tank 13 is connected with a combustion-supporting passage through a silicon oil pipeline and a silicon oil electric tracing pipe 9, an outlet gate valve 16 of the acid mist controller is connected with an SO2 converter through a flange, a valve closing in-place device 17 is fixed on a base 18 through a bottom angle bolt, and the base 18 is fixed on an outlet pipeline of the acid mist controller through a hoop. The valve closing in-place device 17 comprises moving contacts 3-1 and 3-2, static contacts 3-3 and 3-4, contact leading-out wires 3-111, 3-222, 3-333 and 3-444, a fixed base 3-5 and a positioning screw rod 3-10; 3-11 parts of an extension spring; 3-12 parts of a lifting hook; 3-13 parts of universal hook; 3-14 parts of a lifting hook; cable locking heads 3-15, 3-16; a housing 3-17 and an outer support frame 3-18. The fixed base 3-5, the support 3-9, the shell 3-17 and the outer support frame 3-18 are made of PC plastic, and the shell is cylindrical. The base 3-5, the shell 3-17 and the outer support frame 3-18 are made into a whole, the base is provided with internal threads, and the bottom corner of the outer support frame is provided with internal threads; the supports 3-9 are divided into an upper layer, a middle layer and a lower layer, the lower layer of the supports is provided with a left support and a right support, and the supports are rectangular; the three layers of supports are provided with a plurality of holes, the upper layer of support and the lower layer of support are fixed on the base by flat head bolts and are used as fixed supports, wherein the two supports on the lower layer are provided with oblong grooves, and the positions of the supports on the lower layer in the vertical direction can be adjusted. The middle layer is a movable support. The upper layer bracket and the middle layer bracket are connected by two extension springs 11, and two ends of each spring are respectively connected with metal buckles poured on the upper layer bracket and the middle layer bracket. The middle part of the middle layer bracket is slightly wide and thick and is provided with internal threads, the middle part of the bracket is connected with a lifting hook 3-12, and the lifting hook 3-12 is provided with external threads matched with the lifting hook and can be tightly connected with the middle layer bracket. The middle bracket moves up and down along with the hanging objects below the hanging hooks 3-12. In order to ensure that the middle layer bracket moves in the vertical direction without shaking in the horizontal direction, the three layers of brackets are fixed by two positioning screws 3-10, and two metal contacts 3-1 and 3-2 are arranged at two ends of the middle layer bracket as moving contacts; the two lower-layer supports are respectively provided with a metal contact 3-3 and a metal contact 3-4 as static contacts. Contacts 3-1, 3-3, 3-2 and 3-4 form two pairs of normally open contacts, 4 contacts are all connected with 4 metal sheets 3-111, 3-222, 3-333 and 3-444 poured in respective supports, the metal sheets are used as outgoing lines, the end parts of the metal sheets are provided with openings for connecting bolts, the outgoing lines are connected with cables and are respectively connected with a control loop and a signal loop, two sides of a shell 3-17 are provided with two openings, the cables enter from the outside through locking heads 3-15 and 3-16 and are connected with the outgoing lines, universal hooks 3-13 are hung on lifting hooks 3-12 connected with a middle-layer support, lifting hooks 3-14 are hung below the universal hooks 3-13, the lifting hooks 3-14 are welded on the top of an outlet valve rod of an acid mist controller, before the device is put into use, the position of the lower-layer support in the vertical direction needs to be adjusted, the distance between the moving contact and the static contact is consistent with the stroke of the outlet valve; firstly, measuring the distance between the valve and the valve rod from full opening to full closing, then adjusting the position of the static contact in the valve closing in-place device, making the distance between the dynamic contact and the static contact consistent with the measured distance value of the valve stroke, ensuring that the contact in the valve closing in-place device can be closed after the valve is closed in place, and giving out signals. The structure of the bases 3-18 is shown in figure 4. Fig. 4 shows a front view, a top view, a left view and a hoop structure of the base. In a top view, the threaded hole A is used for fixing the valve closing-in-place device on the base; the effect of screw hole B is passed through the staple bolt to the base and is fixed on the acid mist controller outlet pipe, in order to guarantee that the base is fixed more steady, the welding has four supports on the base. And a valve rod of an outlet gate valve of the acid mist controller is connected with the valve closing in-place device through a hole C. The staple bolt top has the trompil, can be connected with the base through screw hole B. An SO3 gas detector 19 is additionally arranged on an outlet pipeline of the acid mist controller, a hot air pipe 20 is additionally arranged on the outlet pipeline, an electric ball valve is arranged on the hot air pipe and used for controlling the on-off of hot air, the temperature of the hot air is 340 ℃, the pressure of the hot air is 6KPa, the hot air pipe is derived from an outlet pipe of the air preheater, one end of the hot air pipe is connected to the outlet pipe of the air preheater, the other end of the hot air pipe is connected to a pipeline behind an outlet valve of the acid mist controller, the connection method is that holes are formed in the pipeline behind the outlet pipe of the air preheater and the outlet valve of the acid mist controller, and then the two ends of the hot air pipe are respectively welded to the opened holes. The pressure of the acid process gas is 1.8KPa, and the temperature is 280-320 ℃. The pressure and temperature of the hot air are both greater than the acid process gas. An electric ball valve is additionally arranged on the hot air pipe and is connected to the pipeline through a flange. The control logic of the electric ball valve is as follows: the added SO3 gas detector is connected with a control loop in series by taking a pair of normally open points S10, when the SO3 gas is detected to flow back into the acid mist controller, the detector gives a signal, and the normally open point S10 connected in series with the control loop is closed to participate in control. A pair of normally open points S20 are arranged in the valve closing in-place device and are connected in series into a control loop, and when an outlet valve of the acid mist controller is closed in place, a normally open contact S20 of the valve closing in-place device is closed to participate in control. When the trouble jumps the car, if the operating personnel can't arrive the scene in the short time and in time close the exit gate valve, in order to prevent that a large amount of acid process gas from flowing back and getting into the acid mist controller, increase a pair of relay normally open contact S30, can be operated by well accuse personnel, control electric ball valve and open. A pair of normally closed points SS of the relay is connected in series into a control loop, so that an operator can close the electric ball valve at any time. A pair of normally-open points KM1 of the electric ball valve is taken as a signal and uploaded to a central control room, and an operator is informed of the action condition of the electric ball valve. A normally-open point S21 of the valve closing in-place device is taken as a signal and uploaded to a central control room to inform operators that the valve is closed in place, the controller also comprises an air preheater which heats air at normal temperature to 340 ℃, participates in impurity removal reaction of the WSA acid making process and has the structure comprising: the electric heater comprises a double-branch K-index thermocouple 5-1, an air inlet 5-2, an air outlet 5-3, a heating pipe 5-4, an air preheater shell 5-5, a wire inlet 5-6 and a connecting flange 5-7, wherein the double-branch K-index thermocouple 5-1, the heating pipe 5-4, the wire inlet 5-6 and the connecting flange 5-7 are integrated to form an electric heater core, the air inlet 5-2, the air outlet 5-3 and the shell 5-4 are integrated to form a heater shell, the heater core and the heater shell are connected through the connecting flange 5-7 by bolts, and normal-temperature air enters from the inlet, is heated after absorbing heat from the heater core and flows out from the outlet.

The working process is as follows: referring to fig. 1-7, a control method for preventing backflow of acidic process gas at an outlet of an acid mist controller is provided, which comprises the following steps:

1) an SO3 gas detector is arranged on the outlet pipe (inside the outlet gate valve) of the acid mist controller to detect whether the acid process gas flows into the acid mist controller.

2) When the acid mist controller jumps, the outlet gate valve is still in a full open state, the acid process gas flows back into the acid mist controller along the outlet pipe due to the stop of the fan in the acid mist controller after the jump, the SO3 gas detector detects the acid gas, and the contact S10 is closed (see fig. 7)

3) To prevent backflow of the sour process gas, the operator may close at the center control contact S30.

4) When S10 and S30 are both closed, the electric ball valve on the hot air pipe is electrified to be opened, the hot air starts to be blown into the SO2 converter, and the acid process gas is prevented from flowing back into the acid mist controller along the outlet gate valve. At the same time, the contact KM1 is closed, and an electric valve action signal D1 is given, so that the operator is informed that the hot air valve is opened. (see FIG. 6)

When the acid mist controller is in cold standby, the control method for preventing the acid process gas at the outlet of the acid mist controller from flowing back comprises the following steps:

1) the outlet gate valve of the acid mist controller is switched from a full-open state to a full-closed state during operation.

2) (see fig. 6 and 7) in the closing process of the outlet gate valve, the valve rod gradually descends, the lifting hooks connected together in the valve closing position device drag the middle-layer support to move downwards, after the valve is completely closed, the movable contact on the middle-layer support is contacted with the fixed contact on the lower-layer support, at this time, the contact S20 is closed (namely, the contact 1 and the contact 3 in fig. 6), the contact S21 is closed (namely, the contact 2 and the contact 4 in fig. 6), an outlet gate valve closing position signal D2 is given, and an operator is informed that the outlet gate valve is closed in position.

3) When the outlet gate valve is in a fully closed state, no acid process gas flows back into the acid mist controller. However, after the outlet gate valve is used for a long time, aging, corrosion and leakage occur, after the sealing performance is reduced, acidic process gas flows back to flow into the acid mist controller, and once the SO3 gas detector detects the acidic gas, the contact S10 is closed.

4) When S10 and S20 are both closed, the electric ball valve on the hot air pipe is powered on to be opened, the hot air starts to be blown into the SO2 converter, and the acid process gas is prevented from flowing back into the acid mist controller along the outlet gate valve. At the same time, the contact KM1 is closed, and an electric valve action signal D1 is given, so that the operator is informed that the hot air valve is opened.

It should be noted that the above-mentioned embodiments are not intended to limit the scope of the present invention, and all equivalent modifications and substitutions based on the above-mentioned technical solutions are within the scope of the present invention as defined in the claims.