CN113145049B - Enamel safety monitoring device of reaction kettle and damage positioning method - Google Patents

Abstract

The present invention discloses a reactor enamel safety monitoring device and a damage location method, including a probe electrode, a transistor Q1, a relay JK1 and a sampling control unit; one end of the probe electrode is inserted into the reactor to contact the reaction medium, and the other end is connected to the power supply through the positive electrode protection resistor R1, and is also connected to the shell grounding point set on the outer wall of the reactor steel container through the normally closed switch K1, and is grounded and connected to the base of the transistor Q1 at the same time; the collector of the transistor Q1 is connected to the power supply, and the emitter outputs the voltage to the sampling control unit; the sampling control unit controls the normally closed switch K1 to be disconnected through the relay JK1 at the beginning of the detection, and then compares the sampling voltage with the preset voltage threshold to determine the degree of damage to the enamel inner layer. The present invention can monitor the operating status of the enamel layer at any place in the reactor at all times, and can display the damage status in real time, and can also eliminate the high-voltage static electricity generated by the fluid medium in the reactor, avoiding serious safety accidents caused by static sparks in the reactor.

Description

Reactor enamel safety monitoring device and damage location method

Technical Field

The invention relates to the technical field of reactor enamel layer detection, in particular to a reactor enamel safety monitoring device and a damage positioning method.

Background Art

Reactors are the main large-scale equipment in chemical systems. The enamel layer of the reactor liner is an acid and alkali resistant protective layer. Due to factors such as thermal stress, mechanical stress and chemical corrosion during operation, it is common for the enamel layer to have different degrees of patchy or crack damage. If the damage is not discovered in time and handled accordingly according to the degree, it may cause rapid corrosion and perforation of the metal body of the reactor, leakage of the reaction medium, and shutdown and other serious safety accidents.

At present, the common practice is that the security personnel visually inspect the reactor before feeding. If there is any damage, they will enter the reactor and use a high-voltage spark leak detector to check whether the enamel is seriously damaged (metal body exposed). If there is no metal exposed, it can continue to be used; otherwise, the reactor will be replaced.

However, current inspection technology has the following disadvantages: 1) Manual inspection is time-consuming, labor-intensive, and inefficient, which seriously affects mass production; 2) Manual inspection has blind spots (i.e. places that inspectors cannot see), resulting in a high rate of missed inspections; 3) Even more serious is the high time blind spot: during the entire period of operation of the reactor in chemical reaction, it is unsafe to inspect. If the enamel is deeply damaged during this period, perforation and leakage accidents are inevitable.

Summary of the invention

In view of the above problems, the purpose of the present invention is to provide a reactor enamel safety monitoring device and a damage positioning method, which can not only fully automatically, fully monitor the operating status of the enamel layer at any location in the reactor at all times and in the entire airspace, and give a corresponding status display in real time, but also eliminate the high-voltage static electricity generated by the fluid medium in the reactor, thereby avoiding serious safety accidents caused by static sparks in the reactor.

The technical solution of the present invention is as follows:

A reactor enamel safety monitoring device comprises a probe electrode, a triode Q1, a relay JK1 and a sampling control unit, and a shell grounding point arranged on the outer wall of the reactor steel container connected to the earth;

One end of the probe electrode is inserted into the reactor to contact the reaction medium, and the other end is connected to the power supply through the positive electrode protection resistor R1. This end is also connected to the grounding point of the shell and the base of the transistor Q1 through the normally closed switch K1. The collector of the transistor Q1 is connected to the power supply, and the emitter outputs the voltage to the sampling control unit.

The sampling control unit controls the normally closed switch K1 to open through the relay JK1 at the moment of sampling to sample the output voltage, and then compares the sampled voltage with a preset voltage threshold to determine the degree of damage to the enamel inner layer.

Furthermore, it also includes a display unit and an alarm unit; if the sampling voltage is less than the first voltage threshold, the display unit indicates "normal"; if the sampling voltage is greater than the first voltage threshold and less than the second voltage threshold, the display unit indicates "minor injury"; if the sampling voltage is greater than the second voltage threshold, the display unit indicates "damaged" and the alarm unit sends out an audible and visual alarm signal.

Furthermore, the voltage threshold is set according to the type of reaction medium.

Furthermore, the probe electrode is installed at the bottom of the reactor and sealed by a polytetrafluoroethylene gasket.

Furthermore, the probe electrode A is a tantalum wire probe electrode.

Furthermore, the sampling control unit processes the sampling data through a CPU chip and sends the processed data to a remote monitoring center.

A damage positioning method based on a reactor enamel safety monitoring device comprises the following steps:

Step 1: When the alarm unit sends out an audible and visual alarm signal, stop stirring immediately;

Step 2: Open the discharge valve to allow the reaction medium to be discharged slowly at a specific flow rate;

Step 3: When the sound and light alarm signal stops, immediately close the discharge valve, observe and record the liquid level of the reaction medium, and the damaged part is within the range of the annular inner wall above the liquid level;

Step 4: Discharge all reaction media, determine the specific location of the damage within the annular inner wall, and repair it in time.

Compared with the prior art, the present invention has the following beneficial effects:

1. The monitoring of the present invention is fully automatic and does not require manual participation; there is no blind spot in the monitoring, and all spaces that the reaction medium in the reactor can reach are the effective monitoring range of the system;

2. The monitoring of the present invention is full-time. As long as there is reaction medium in the reactor, the system is in the monitoring state even when the reactor is in working state;

3. The present invention has a fast response time, and enamel damage can be detected in just a few seconds;

4. The measuring probe electrode of the monitoring system of the present invention contacts the reaction liquid medium of the reactor, and the electrostatic charge generated by the stirring of the reaction medium is led to the ground discharge circuit through the monitor, thereby completely eliminating the static electricity and completely eliminating the most common safety hazards in the chemical industry; at the same time, it can effectively eliminate the interference of static electricity on the sampling voltage, making the detection results more accurate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a reactor enamel safety monitoring device according to the present invention.

In the figure: 1-motor; 2-agitator; 3-reactor; 4-shell grounding point; 5-polytetrafluoroethylene gasket; 6-leakage valve; 7-enamel inner layer; 8-steel container; 9-reaction medium; 10-probe electrode.

DETAILED DESCRIPTION

The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

Embodiment 1: The reactor enamel safety monitoring device as shown in Figure 1 includes a probe electrode 10, a transistor Q1, a relay JK1 and a sampling control unit, and an outer shell grounding point 4 arranged on the outer wall of the steel container 8 of the reactor 3 and connected to the earth; one end of the probe electrode 10 is inserted into the reactor 3 to contact the reaction medium 9, and the other end is connected to the power supply through the positive electrode protection resistor R1, and the end is also connected to the outer shell grounding point 4 and the base of the transistor Q1 through the normally closed switch K1; the collector of the transistor Q1 is connected to the power supply, and the emitter outputs the voltage to the sampling control unit; the sampling control unit controls the normally closed switch K1 to be disconnected through the relay JK1 at the moment of sampling to sample the output voltage, and then compares the sampled voltage with the preset voltage threshold to determine the degree of damage to the enamel inner layer 7.

The normally closed switch K1 controlled by the relay JK1 short-circuits the probe A and the metal shell B of the reactor, and releases the high-voltage static electricity generated by the reaction medium and the induced charge generated by the metal container through the wire to the ground. At the moment of detection, K1 is disconnected, Vi is output, and the corresponding monitoring indication signal is given after current amplification, A/D conversion, storage, identification, control and other processing of the subsequent circuit.

The present invention connects the reaction medium 8 and the shell grounding point 4 to the earth through the normally closed switch K1 of the relay, and promptly eliminates the static electricity that is rapidly accumulated due to high-speed stirring. On the one hand, it can avoid the potential safety hazard caused by static electricity, and on the other hand, it can eliminate the interference of static electricity on the sampling signal during voltage sampling, so that the detection result is more accurate. The relay is selected in the discharge circuit, which can conveniently and effectively realize the above functions. During the non-sampling point period, the normally closed switch K1 is in a closed state, and the static electricity generated in the reactor can be smoothly and timely discharged into the earth without any static electricity accumulation, which is something that the original parts such as lightning protection diodes cannot achieve. Because there is no static electricity accumulation, at the sampling point, the normally closed switch K1 needs to be disconnected. At the moment when the reaction medium 8 and the shell grounding point 4 are disconnected, the collected voltage signal can more truly reflect the damage of the enamel layer and avoid misjudgment caused by static electricity interference.

Embodiment 2: It also includes a display unit and an alarm unit; if the sampling voltage is less than the first voltage threshold, the display unit indicates "normal" and the green light is on; if the sampling voltage is greater than the first voltage threshold and less than the second voltage threshold, the display unit indicates "minor injury" and the yellow light is on; if the sampling voltage is greater than the second voltage threshold, the display unit indicates "damaged", and the alarm unit sends out an audible and visual alarm signal and the red light is on.

The voltage threshold can be set according to the type of reaction medium 9 and can be set differently according to the conductivity of the reaction medium 9 itself.

The insulation resistance of the enamel layer is detected by the voltage divider circuit, which has a simple circuit structure, is reliable, and has strong anti-interference ability. In Figure 1, the +5V power supply, positive electrode protection resistor R1, probe electrode A, Rx, grounding resistor R0, normally closed switch K1 and negative electrode are connected in series to form a voltage divider circuit. Rx is the total resistance between the reaction medium of the enamel kettle and the steel container of the reactor. Rx is mainly determined by the condition of the inner layer of the reactor enamel. The detection conditions are divided into the following categories:

1) If the enamel layer is intact, the insulation resistance of Rx is very large, and the potential Vi transferred to the base of the transistor Q1 through the voltage divider circuit is very low;

2) If the enamel layer is damaged, the insulating layer becomes thinner and the Rx resistance becomes smaller, then Vi will increase;

3) When the enamel layer is severely damaged, so that the metal container is in direct contact with the reaction medium, Rx will drop to the minimum, and the voltage Vi transferred to the base of Q1 through the voltage divider circuit will reach a maximum value. After being triggered, the alarm circuit will give an audible and visual alarm signal.

Although the base glaze of the enamel liner has stronger adhesion, its insulation and corrosion resistance are lower than the external enamel layer. Therefore, if there are cracks in the enamel layer, Rx will become smaller as the crack depth deepens. In actual production, it will take several days or dozens of days for the enamel layer to completely break and expose the base glaze. If the external steel container is exposed, it will dissolve in one to two hours and leak the reaction medium. Therefore, there will be a large numerical span between the first voltage threshold and the second voltage threshold. Once the yellow light is on during the test, it means that the enamel layer has begun to show minor injuries such as shallow cracks. It can continue to be used, but issuing an early warning can facilitate the subsequent arrangement of production adjustments and preparations for repair work.

Example 3: The probe electrode 10 is installed at the bottom of the reactor 3 and sealed by a polytetrafluoroethylene gasket 5. The probe electrode 10 is a tantalum wire probe electrode. The sampling embedded insulating sealing gasket probe electrode of the present invention embeds a tantalum metal wire as a measuring probe on the polytetrafluoroethylene sealing gasket and is placed at the discharge port of the reactor. The inner side of the tantalum wire is exposed and in contact with the reaction medium, and the outer side is connected to the +5V bias of the monitor by a wire; this structure not only plays the role of insulation and sealing (to prevent the reaction medium from leaking out), but also allows the probe electrode to be placed at the bottom of the reactor, achieving a full-space monitoring effect without being restricted by the height of the medium liquid level.

The probe electrode of the present invention is connected to the housing and the ground via a relay normally closed switch, so that the static electricity generated by the high-speed flowing liquid medium of the reactor can be reliably eliminated, eliminating the biggest hidden danger caused by static electricity discharge in chemical workshops. The present invention uses a CPU chip to process measurement data, can be remotely centralized monitored through a data bus, and can remotely set different monitoring alarm threshold resistors according to different reaction media.

Embodiment 4: After damage is detected, the present invention also provides a simple and effective damage location method, the specific steps are as follows:

Step 1: When the alarm unit emits an audible and visual alarm signal, stop stirring immediately.

Step 2: Open the discharge valve to allow the reaction medium to be discharged slowly at a specific flow rate; the liquid level drop rate in this embodiment is 2 cm/min.

Step 3: When the sound and light alarm signals stop, immediately close the discharge valve, observe and record the liquid level of the reaction medium. The damaged part is within the range of the circumferential inner wall above the liquid level (1-4 cm).

Step 4: Discharge all reaction media, determine the specific location of the damage within the annular inner wall, and repair it in time.

The positioning method of the present invention is simple and effective, and can quickly locate the damaged position. It can not only avoid secondary damage to the enamel layer by the existing electrode detection method, but also is more rigorous, accurate and efficient than the existing method that only relies on manual visual inspection.

Claims (1)

1. The breakage positioning method of the enamel safety monitoring device of the reaction kettle is characterized in that the enamel safety monitoring device of the reaction kettle comprises a probe electrode (10), a triode Q1, a relay JK1, a sampling control unit and a shell grounding point (4) which is arranged on the outer wall of a steel container (8) of the reaction kettle (3) and is connected with the ground;

One end of the probe electrode (10) is inserted into the reaction kettle (3) to be in contact with the reaction medium (9), the other end of the probe electrode is connected with a power supply through the positive electrode protection resistor R1, and the end of the probe electrode is also connected with the shell grounding point (4) and the base electrode of the triode Q1 through the normally closed switch K1; the collector of the triode Q1 is connected to a power supply, and the emitter outputs voltage to the sampling control unit;

The sampling control unit controls the normally closed switch K1 to be disconnected through the relay JK1 at the sampling moment to sample the output voltage, and then compares the sampled voltage with a preset voltage threshold value to judge the damage degree of the enamel inner layer (7);

The system also comprises a display unit and an alarm unit; if the sampling voltage is smaller than the first voltage threshold value, the display unit indicates normal; if the sampling voltage is larger than the first voltage threshold and smaller than the second voltage threshold, the display unit indicates 'light injury'; if the sampling voltage is greater than the second voltage threshold, the display unit indicates breakage, and the alarm unit sends out an audible and visual alarm signal;

The damage positioning method comprises the following steps:

step1: when the alarm unit sends out an audible and visual alarm signal, stirring is stopped immediately;

step 2: opening a discharge valve to slowly discharge the reaction medium at a specific flow rate;

step 3: when the audible and visual alarm signal stops, the material leaking valve is immediately closed, the liquid level of the reaction medium is observed and recorded, and the damaged part is located in a section of annular inner wall range above the liquid level;

step 4: discharging all the reaction medium, determining the specific position of damage in the range of the annular inner wall, and repairing in time.