Fatigue fracture occurred as the crack continued to expand; measuring the dimensions of both sides of the AA section, it was found that the piston rod was stretched to analyze the above situation, and the AA was often broken due to insufficient rigidity. The length of the piston is Υ1176, and the diameter of the piston is the largest in each section of the 6M25 compressor, and the distribution of the cylinder valve is distributed to the left and right, 6 intake valves on one side and 6 outlet valves on one side. During the compression process of a piston, due to the uneven distribution of airflow, the end face of the piston is affected by the surge of the airflow, which will inevitably exert a large alternating bending stress on the section AA; although the tensile and compressive strengths are sufficient, the diameter is small. Insufficient rigidity, due to the alternating load force, the plastic yield deformation first occurs at the weak point of the AA end face thread. As the deformation continues to expand, the piston rod is elongated and thinned on the basis of the original size. Stress concentration occurs at the thread, cracks are gradually generated, and are continuously expanded by the alternating load until fatigue fracture.

After the above reasons are analyzed, the modification plan determines to increase the diameter of the joints at both ends of the piston rod and increase the rigidity, so as to effectively prevent the piston rod from being insufficient in rigidity and causing plastic yield deformation. The diameter is increased from the original M56×4 to M85×4. At the same time, the crosshead is replaced, and the inner hole of the piston and the end hole of the sealing head are modified. The connection mode is changed from hydraulic connection to mechanical connection. Two-stage to six-stage piston rod use The second-stage piston rod was put into operation in May 1998 and was completed in April 2001. A total of four pieces were broken, and the transformation plan was the same as that of one section of the piston rod.

The fracture frequency of the second-stage piston rod is lower than that of a piston rod. It is because of the discussion on the reasons for the scrapping of the dissolved acetylene cylinders in service and the correct transportation and handling of the acetylene cylinders are the key to prolonging the service life of the cylinders.

Dissolved acetylene gas cylinders are mobile pressure vessels. They are complicated in use and have many links. Accidents have occurred in manufacturing, sales, filling, use, inspection and transportation. The management level needs to be improved. Therefore, the state implements a mandatory three-year periodic inspection of dissolved acetylene cylinders to ensure the safety of in-service acetylene cylinders.

In-service gas cylinder testing and failure analysis of failure reasons GB13076-1991 "dissolved acetylene cylinders periodic inspection and assessment" in the service cylinders from the appearance, welds, valve seat and plug seat, packing, wall thickness five aspects , made a retirement indicator. We strictly observe that the diameter of the second-stage piston is much smaller than the diameter of one-stage piston. It is less affected by the distribution force of the airflow and the surge. The alternating bending stress generated at the joint between the piston rod and the crosshead is small, so the number of breaks is small. The three- to six-stage piston rods are in good condition because the three- to six-stage pistons have smaller diameters and are less affected by airflow distribution and surge. The stiffness of the M56×4 thread diameters has fully met the requirements of their work. Will break due to insufficient stiffness.

There are problems in the one- to six-stage cooler and the modification of the one- to four-stage water cooler internals. The one- to four-stage cooler is a common carbon steel shell-shell water cooler. The four sections are used in two horizontal series in recent years. During the use, it is found that the lower part of the one- to three-stage water cooler internals (tube process) is corroded faster, and two to three inner cores are replaced almost every year, and the internal corrosion of the four-stage water cooler is severe, which gives stable production and Energy saving and consumption reduction have extremely adverse effects.

Through careful analysis, the reform measures believe that the acidity of the oil water separated from the one- to four-stage water cooler is large, and the oil and water cannot be fully discharged and cause corrosion. After two years of gradual transformation, the inner core of the first to fourth sections was changed from the original carbon steel material to the stainless steel material. The effect is very good.

Five or six-stage coolers have problems and modifications. Five- and six-stage cooler scales The six-stage cooler inner tube is a high-pressure tube bundle, and the outer casing is a Υ159 low-pressure water pipe sleeve. Due to the large mud content of the circulating water system of our company, the system water pressure is low (about 117.6 kPa), the spacing between the inner and outer tubes of the fifth and sixth sections is small, the water is restricted by water during the flow, and the boundary layer is thickened and long-term. The heat transfer of the inner tube causes fouling on the surface to block the flow path, and the heat exchange effect is extremely poor. The 6M25 compressor was put into operation for less than two years. The scale between the inner and outer tubes of the five or six-stage cooler was almost blocked, and the heat generated by the compression of the high-pressure gas could not be effectively exchanged, resulting in frequent five- and six-stage valves. Leaked and could not work.

The outer tubes of the fifth and sixth sections of the renovation measures were changed from the original Υ159 to Υ194, which increased the flow passage, reduced the pipeline resistance at this part, and delayed the scaling. After more than two years of use, the effect has changed a lot.

Other transformations of the four-stage cylinder air chamber and the water chamber joint due to design defects, causing the air chamber to collide with the water chamber, replacing the two cylinders in a short time. For this reason, we thicken the joint between the air chamber and the water chamber. And the ribs are set up; 2 five-stage cylinders are scrapped due to cracks in the longitudinal part, the material is changed from the original cast iron to cast steel; the third and sixth-stage pistons are changed from the outer layer to the babbitt alloy (easy delamination) The battalion is hanged for the dovetail groove at both ends; the cooling water of the 4th and 6th section of the stuffing box is changed from circulating water to soft water to prevent scaling.

Through the gradual improvement and modification of the various components of the 6M25 compressor in recent years, the problems of the fracture of the first and second piston rods and the corrosion and scaling of the cooler have been basically solved. Since April 2001, the first and second stage pistons have been solved. The rod never breaks, and the one- to four-stage coolers no longer leak due to corrosion. The fouling of the five- and six-stage coolers is further alleviated, and other parts have been improved accordingly. This is a long-term operation of the compressor. Created conditions.

Manual Coal Steam Boiler

Manual Coal Steam Boiler Features

1.The boiler has big drum and have big enough space for water. Compared with the SZL series, the DZL boiler is more adaptable to poor water quality. Moreover , when the boiler scaled, it is convenient for maintenance.

2. Adopting convex tube plate, prevent tube plate cracking and simplify the structure of canceling the tension bar.

3. The Wing-shape flue arrangement, the flue gas is three pass, reduce the smoke temperature of high temperature area tube plate, thereby preventing the cracking of tube plate and Boiler tube explosion.

4. Adopting threaded smoke-tube technology, strengthen heat transfer, reduce the number of pipes and the size of boiler shell; reduce the thermal stress at the end of the pipe, and prevent cracking of the tube plate. At the same time, due to the self-cleaning ability of the flue gas in the threaded pipe, avoid the accumulation of dust in the tube.

5. The boiler has sufficient output, fast speed heating and high thermal efficiency.

Manual Coal Boiler,Industrial Manual Coal Boiler,Manual Coal Fired Boiler,Manual Coal Fired Steam Boiler,Manual Type Coal Boiler

Henan Yuanda Boiler Co., Ltd. , https://www.industrysboiler.com