Compressors and chemical pumps are composed of many supporting auxiliary machines. Auxiliary machines, as an important part of the main machine, should be given high priority. If the auxiliary machine has problems, the main machine cannot work normally. Therefore, the auxiliary machine should also strive to control the quality and make the equipment factory. test.
Introduction
The normal operation of the moving equipment is inseparable from the quality of the auxiliary equipment. Therefore, as the general contractor, it is necessary to not only control the quality of the main machine but also pay enough attention to the quality of the auxiliary equipment, so as to ensure the safe production of the device.
In the chemical plant, the moving equipment (compressor, chemical pump) is the core equipment of the chemical plant, and its quality is related to the safe production of the entire chemical plant. Compressor and chemical pump are a separate and independent production system. They are composed of many supporting auxiliary machines and are involved in many aspects. For example, compressor auxiliary machines have oil stations, water stations, filters, and chemical pump auxiliary machines have oil stations. Etc., the scope of coverage includes: technology, pumps, static equipment, electrical appliances, instruments, etc., which shows their complexity. The quality of the auxiliary machine is directly related to the normal operation of the compressor and chemical pump, as well as the safe production of the entire device. Since the beginning of this year, several safety accidents have occurred in the national chemical industry, which makes us soberly aware of the importance of controlling the quality of equipment. There is a problem in one of the links in the entire production operation system. If not handled properly, it will trigger the "domino effect" to crash the entire production device, and there are many cases of catastrophic consequences. People often say: "A thousand miles of embankment breaks down in an ant den", which makes a lot of sense. Therefore, the project must not only control the quality of the compressor and the main pump of the chemical pump, but also control the auxiliary machinery they carry, remove all hidden dangers of safe production, and implement the quality management of the equipment to the ground!
Engineering companies generally control the compressor main engine and the chemical pump main engine very rigorously, and attach great importance to it. The basic production process, from procurement, design and dispatch of supervised manufacturing engineers to the factory, to the performance test and mechanical operation test before the factory leaves the factory Controlled the quality of the compressor host and chemical pump host. However, during the commissioning and commissioning of the site, various problems often occur in the compressor auxiliary machinery and chemical pump auxiliary machinery, which affects the normal operation of the device. The following is an analysis of several problems that occur on the site.
Case 1
A PC project company contracted by the engineering company has a total of four devices, and the following problems occur in the residue hydrogenation device.
When the residual oil K102 new hydrogen compressor was tested, three of the five transmitters on one unit's oil station failed at the same time. Because of the three-two-interlock condition, the oil station could not run and the compressor could not be tested. After the emergency replacement of the ROSEMOUNT3051 transmitter, the compressor will run normally.
Reason for analysis: The reciprocating compressor main factory ignored the quality control of the auxiliary equipment and did not control the quality of the subcontractor. The manufacturing supervision engineer stationed in the factory only carried out quality control on the main compressor and did not go to the auxiliary equipment factory for factory inspection. Caused problems in the quality of on-site auxiliary machines. Fortunately, there are many ROSEMO UNT3051 brand transmitters in the spare parts library of the project team. The timely replacement did not adversely affect the normal commissioning of the compressor. The design department and the OEM signed the technical agreement with the instrument brand: ROSEMOUNT, EJX and other brands. The performance of the two brands is reliable and stable. However, for the benefit of the manufacturer, the manufacturer has changed to a domestic brand transmitter without notifying the general contractor. On-site quality problems have prevented the commissioning of the compressor from proceeding normally. If it is not replaced in time, it will bring hidden production safety risks to the future operation of the unit.
Rectification plan: In response to this situation, the project team decided that the host manufacturer must replace the transmitter according to the technical requirements. After the coordination of the procurement department, the host factory finally made the replacement.
Summary of experience: In future projects, the project department will send inspection engineers and engineers from the main engine factory to the auxiliary machinery factory to do the factory inspection.
Case 2
During the installation of the equipment, it was found that the six buoys carried on the liquid separator tank of the compressor inlet on the east side of the reciprocating machine of a wax oil hydrocracking unit were a domestic manufacturer. In the technical agreement signed with the compressor main engine factory, the liquid level was required. It uses products from Shanghai Xindong, Dandong Tongbo, K-TEK, MAGNETROL and other brands.
Reasons for analysis: The manufacturing supervision engineers in the factory only carried out quality control on the compressor main engine, neglecting the quality control on the auxiliary machinery, which caused the supplier to replace high quality with low quality and caused losses to the project team.
Treatment plan: According to this situation, the project team instructs the compressor OEM to replace the six buoy manufacturers as the brand specified in the technical agreement according to the technical agreement. And in the future work to strengthen the quality control of compressor auxiliary machinery, if necessary, the project team will send quality engineers and compressor auxiliary machinery factory to the auxiliary machinery factory for inspection.
Case 3
The reciprocating compressor comes with a filter to reach the construction site. (K-102A/B/C) The built-in filter has the following serious problems. The maximum test pressure of the filter is 25.8MPa, a total of 32, 8 welding quality problems ( As shown in Figure 1, 2, 3).
Reason for analysis: The reciprocating compressor comes with a filter of 25.8Mpa. Before leaving the factory, each filter should be tested for nondestructive testing and hydraulic pressure. Due to the work error of the host factory, the high-pressure filter of the sub-supplier has not been directly inspected. At the factory, if the on-site inspection engineer does not work carefully, it will cause unimaginable serious consequences.
Treatment plan: The project team decided to return all unqualified high-pressure filters. The manufacturer's re-soldering process is to carry out non-destructive inspection before leaving the factory, and the project team will send inspection engineers and OEMs to send engineers to sub-suppliers for hydraulic tests.
Rectification measures: 8 filters of auxiliary equipment manufacturers were witnessed by engineers dispatched by the host plant and the project team. After the non-destructive testing of the 8 high-pressure filters, the technical requirements were met after the pressure test. The equipment was successfully installed and commissioned after arriving at the site. ,run.
Case 4
At a construction site in a domestic project: the local environment: the winter is extremely cold, the minimum temperature is -35 ℃--40 ℃, the commissioning of the equipment is facing a severe test.
The following problems occurred in the motor during the trial operation of the heating system:
Pump bit number: BL-3705, the motor bearing holding shaft occurred during the trial operation of the pump, which eventually caused the motor coil to burn, and the entire motor was scrapped.
Reason for analysis: The pump is supplied by a well-known domestic pump factory, and the supporting motor is supplied by a well-known domestic explosion-proof motor factory. But the motor bearing is not the imported brand SKF/NSK bearing specified in the technical agreement, but a product of a domestic factory, and the lubricating fluid (low temperature lithium base grease) that comes with the motor factory fails at a low temperature of -40 ℃ and cannot be cooled. , The effect of lubrication causes the bearing and the motor shaft to be held together, causing the motor coil to burn and cause a quality accident.
Rectification measures: The engineering company issued a notice to the pump factory according to the situation on the scene, requesting the pump factory to replace all the bearings in the current motor with imported brands (SKF/NSK) according to the requirements of the technical agreement, and use 7014 low temperature grease for the lubricant. Under the cooperation of the purchasing department, the construction department and the on-site owners, the on-site motors were rectified.
After the rectification is completed, the motor runs normally and the delivery pump operates normally during the trial operation.
The control and management of sub-suppliers is actually a very complicated matter. The technical agreement has clearly stipulated the brand of the motor and the brand of the motor bearing. However, due to the management of the pump factory, the quality of the supporting motor is out of control. The project team should also send engineers to the supporting factory to monitor the equipment and strictly review the motor warranty documents.
Successful case: Quality control of pumping station in continuous reformer
The pump water station is a supplementary auxiliary machine for the boiler feed water pump. Due to its importance, the engineering company purchases it separately. The procurement is completed through a series of work such as contract signing, reminder, and submission of design documents. Ex-factory inspection, the water station is mainly composed of pumps, water tanks, and various instruments. The pumps are operated continuously for 24 hours.
Main parameters: water pump: flow rate: 85m3/h, pressure: 0.5MPa, (2 sets)
Performance inspection: 24 hours continuous operation of the water pump, conclusion: qualified
Inspection of supporting equipment of water station:
Water tank: stainless steel Volume: 17m3 Meet the technical agreement requirements
Inspection of pump brand of water station
Inspection of motors for pumps in water stations Comply with technical agreement, domestic famous brands
The inspection of water station instruments and meters complies with the provisions of the technical agreement, and is a well-known domestic brand
Warranty documents: inspect the inspection report of the mechanical properties and chemical composition of the pump body, pump cover, impeller, and shaft of the pump, and meet the technical agreement requirements after inspection. Examine the non-destructive inspection reports of the pump body, pump cover, impeller, shaft, over-flow weld, impeller ring, and pump ring, and meet the technical agreement requirements after inspection. And the factory performance test report and mechanical operation report of the pump are inspected and qualified after the inspection.
Motor inspection: Famous domestic motor brands meet the technical agreement requirements. Check the factory performance report of the motor and pass the inspection.
Other brands such as instruments and meters meet the technical agreement requirements.
The entire inspection process was very comprehensive and successful. The pump softened water station performed well after arriving at the site (see Figures 4, 5, and 6).
Conclusion
The quality of compressors and chemical pump supporting auxiliary machinery is very important for the success of the engineering company's project. Therefore, the management of the supporting sub-suppliers of the main engine factory should be strengthened. The project team can send inspection engineers and inspection engineers of the main engine factory to the sub-suppliers Do the factory inspection of the equipment, and inspect the quality assurance documents to maximize the control and protection of the quality of sub-supplier auxiliary machines.
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