CN215506310U

CN215506310U - Hot area acid-base cleaning system for low-temperature methanol washing process

Info

Publication number: CN215506310U
Application number: CN202120815257.8U
Authority: CN
Inventors: 历荣; 李储祥; 高成志; 陈波; 杨磊; 徐剑虹; 成利军; 高君; 王飞; 胡成章
Original assignee: Datang Hulunbeier Fertilizer Co ltd
Current assignee: Datang Hulunbeier Fertilizer Co ltd
Priority date: 2021-04-21
Filing date: 2021-04-21
Publication date: 2022-01-14
Anticipated expiration: 2031-04-21

Abstract

And a hot-zone acid-base cleaning system in a low-temperature methanol washing process. The dirt blocks the equipment and the pipeline, the system efficiency of the production device is reduced, the energy consumption is increased, when the system is serious, the filter at the inlet of the pump blocks the pump, the pump is pumped out, the mechanical seal is damaged, the device is forced to stop production, and huge economic loss is caused. The utility model comprises the following components: the first cleaning loop comprises a thermal regeneration tower (3), a methanol-water separation tower (2), a thermal regeneration tower top water cooler (4), a hydrogen sulfide gas separation tank (5), a hydrogen sulfide fraction cold exchanger (6), a hydrogen sulfide fraction ammonia cooler (7) and a hydrogen sulfide gas separation tank (8). The method is used for acid-base cleaning in the hot zone in the low-temperature methanol cleaning procedure.

Description

Hot area acid-base cleaning system for low-temperature methanol washing process

Technical Field

The utility model relates to a hot zone acid-base cleaning system in a low-temperature methanol cleaning process.

Background

In the original driving process of the hot zone of the low-temperature methanol washing process, rolling scales, oil dirt, mud, sand, sundries, welding slag, various oxides and other dirt remained in the hot zone and attached to the inner wall of the hot zone during construction and installation are inevitably generated in the manufacturing and installation processes of equipment and pipelines. Due to the material of each tower and high-temperature weak acid methanol/water/CO₂/H₂Under the condition of running of the S medium, pipelines and equipment are prevented from being blocked due to the running of the S medium when a test car is tested; damage to operating equipment, valves and instrumentation; a technology for cleaning acid and alkali in a hot zone in a low-temperature methanol washing process is an important test run procedure for ensuring smooth test run and long-period safe production of a device. The dirt blocks the equipment and pipelines, the system efficiency of the production device is reduced, the energy consumption is increased, in severe cases, the filter at the inlet of the pump blocks the pump, the mechanical seal is damaged in the pumping-out state of the pump, the device is forced to stop production, and huge economic loss is caused.

Disclosure of Invention

The utility model aims to provide a hot-zone acid-base cleaning system in a low-temperature methanol washing process.

The above purpose is realized by the following technical scheme:

a low temperature methanol washing process hot zone acid-base cleaning system comprises: the first cleaning loop comprises a thermal regeneration tower, a methanol-water separation tower, a thermal regeneration tower top water cooler, a hydrogen sulfide gas separation tank, a hydrogen sulfide fraction cold exchanger, a hydrogen sulfide fraction ammonia cooler and a hydrogen sulfide gas separation tank;

the top liquid outlet of the methanol water separation tower is communicated with the liquid inlet of the thermal regeneration tower through a pipeline, the top liquid outlet of the thermal regeneration tower is communicated with the top water cooler of the thermal regeneration tower through a pipeline, the top water cooler of the thermal regeneration tower is communicated with the hydrogen sulfide gas separation tank through a pipeline, the hydrogen sulfide gas separation tank is communicated with the hydrogen sulfide fraction cold exchanger through a pipeline, the hydrogen sulfide fraction cold exchanger is communicated with the hydrogen sulfide fraction ammonia cooler through a pipeline, and the hydrogen sulfide fraction ammonia cooler is communicated with the hydrogen sulfide gas separation tank through a pipeline;

the second cleaning loop comprises a methanol-water separation tower feed pump, a lean methanol filter and a methanol-water separation tower feed heater;

the liquid outlet of methanol-water separation tower charge-in pump divide into two the tunnel, communicate with poor methanol filter all the way, another way with the N9 port intercommunication of thermal regeneration tower, poor methanol filter with methanol-water separation tower feed heater pass through the pipeline intercommunication, methanol-water separation tower feed heater with methanol-water separation tower's inlet intercommunication.

The tower top of the hydrogen sulfide gas separation tank is communicated with a first liquid return port.

The hot area acid-base cleaning system in the low-temperature methanol washing process is characterized in that the thermal regeneration tower is communicated with the poor methanol cooling tower through a pipeline, and the poor methanol cooling tower is communicated to a second liquid return port.

Has the advantages that:

1. the utility model reduces the scaling and corrosion speed by pickling, cleaning and passivating the treating agent, and restores the normal cleaning degree of the production device according to the requirement by neutralizing and cleaning the deposited dirt by acid and alkali. The integral driving of the methanol hot-washing area device is ensured to be smooth.

Description of the drawings:

FIG. 1 is a schematic structural view of the present invention;

in the figure: 1. a liquid inlet; 2. a methanol-water separation tower; 3. a thermal regeneration column; 4. a water cooler at the top of the thermal regeneration tower; 5. a hydrogen sulfide gas separation tank; 6. a hydrogen sulfide fraction cold exchanger; 7. a hydrogen sulfide fraction ammonia cooler; 8. a hydrogen sulfide gas separation tank; 9. a first liquid return port; 10. a methanol-water separation tower feed pump; 11. a lean methanol filter; 12. a methanol-water separation tower feed heater; 13. a lean methanol cooling tower; 14. and a second liquid return port.

The specific implementation mode is as follows:

example 1:

a low temperature methanol washing process hot zone acid-base cleaning system comprises: the device comprises a first cleaning loop and a second cleaning loop, wherein the first cleaning loop comprises a thermal regeneration tower 3, a methanol-water separation tower 2, a thermal regeneration tower top water cooler 4, a hydrogen sulfide gas separation tank 5, a hydrogen sulfide fraction cold exchanger 6, a hydrogen sulfide fraction ammonia cooler 7 and a hydrogen sulfide gas separation tank 8;

the second cleaning loop comprises a methanol-water separation tower feed pump 10, a lean methanol filter 11 and a methanol-water separation tower feed heater 12;

Example 2:

according to the hot zone acid-base cleaning system in the low-temperature methanol washing process in the embodiment 1, the top of the hydrogen sulfide gas separation tank is communicated with a first liquid return port 9.

Example 3:

according to the hot zone acid-base cleaning system in the low-temperature methanol washing process in the embodiment 1 or 2, the thermal regeneration tower is communicated with the lean methanol cooling tower 13 through a pipeline, and the lean methanol cooling tower is communicated to the second liquid return port 14.

The working principle is as follows: cleaning procedure and use of chemicals: the cleaning procedure is generally systematic water washing → degreasing → water washing → acid washing → rinsing → neutralization and passivation → inspection and artificial treatment

Washing with water

The water washing is used for checking the leakage condition of a temporary system and simultaneously removing dust, silt, fallen metal oxides, welding slag and other loose and easily removed dirt in the system. During leakage detection, high-level water injection and low-point discharge are firstly needed so as to drain impurities and control the balance of water inlet and outlet. The flushing flow rate is generally more than 0.15m/s, and if necessary, the forward and reverse directions can be switched, the flushing is carried out until the effluent is visually observed to be transparent and has no particles, and then the system is filled with water. And (4) closing the outlet valve, boosting the pressure to 0.4-1.0Mpa, checking whether the joints of all welding seams, valves, flanges, short pipes and the like have leakage or not, repairing, and performing the next procedure operation after the joints are qualified.

The formula of the cleaning solution suitable for carbon steel, stainless steel and other materials for degreasing and cleaning is as follows:

NaOH：0.5-2.5%；Na₂CO₃：0.5-2.5%；Na₃PO₄: 0.5-2.5%, surface activity0.05-1.0% of sex agent and the like.

The operation method comprises charging preheated water (or heating with steam) into the system, circulating, adding degreasing cleaning solution at 80 deg.C+5 ℃ is adopted. Checking alkalinity, oil content and temperature for 1-2 times every 30min, when the system degreasing liquid, alkalinity and oil content are almost balanced, and dirt on the monitoring pipe section is completely removed, finishing degreasing, and extruding the degreasing liquid by nitrogen. And then flushing residual alkaline cleaning agent in the system with clear water, monitoring the pH value and the concentration every 10min, and finishing flushing when the pH value tends to be stable.

The formula of the cleaning agent for acid cleaning is as follows: HNO₃：6%-10%；H₃C₆H₅O₇: 1 percent; lan-826: 0.25% -0.30%; OP-10: 1 percent. When cleaning liquid returns, the cleaning liquid is emptied and cleaned circularly, and the direction is switched periodically. And pollution discharge and emptying are performed at regular intervals in the circulating process, so that air resistance and blockage caused by draining are avoided, and the cleaning effect is not influenced. Detecting the concentration and pH value of the acid solution 1-2 times every 30min, detecting the concentration of iron ions once, and observing the corrosion rate at any time, wherein some iron ion inhibitors can be properly added. When the concentration of the cleaning liquid is not reduced any more, the concentration of the metal ions is basically stable, the dirt of the monitoring pipe section is completely removed, and the pickling end point is reached when the whole pipe section is natural. The pickling time is about 4-6 hours.

After the acid washing, the acid liquor and the fallen solid particles in the system are washed by clean water for rinsing and passivation treatment. And (3) carrying out open-circuit cleaning on the whole system by using a large amount of water, continuously and alternately starting the system to conduct showers so as to completely discharge impurities and residual liquid deposited in the short pipe, measuring the pH value every 10min in the cleaning process, and stopping cleaning when the pH value is close to neutral.

The purpose of the rinse is to complex and remove the residual ferric ions in the system to ensure subsequent passivation.

The formula of the passivation solution is as follows: NaNO₂：1%-2%；Na₂CO₃: 0.5-1.0%, adjusting pH with ammonia water, after rinsing, adjusting pH =9-10 with ammonia water directly if the iron ion content in the solution is more than 500mg/L, and adding passivation solution for passivation treatment. The temperature of the passivation solution is maintained at 60-80 ℃.In the passivation process, high-point emptying and low-point blowdown are continuously carried out to eliminate air resistance, avoid dead corners and ensure the passivation effect. The pH and temperature are measured every 30min, with a passivation time of typically 4-6 hours.

After cleaning, the cleaning and passivation effects are checked, accepted and evaluated in quality.

Claims

1. A low temperature methanol washing process hot zone acid-base cleaning system comprises: first washing return circuit and second wash the return circuit, characterized by: the first cleaning loop comprises a thermal regeneration tower, a methanol-water separation tower, a thermal regeneration tower top water cooler, a hydrogen sulfide gas separation tank, a hydrogen sulfide fraction cold exchanger, a hydrogen sulfide fraction ammonia cooler and a hydrogen sulfide gas separation tank;

2. The low temperature methanol washing process hot zone acid-base cleaning system of claim 1, wherein: the top of the hydrogen sulfide gas separation tank is communicated with a first liquid return port.

3. The low temperature methanol wash process hot zone acid-base cleaning system of claim 2, characterized by: the heat regeneration tower is communicated with the poor methanol cooling tower through a pipeline, and the poor methanol cooling tower is communicated to a second liquid return port.