The key to the correct transport and handling of the life of acetylene cylinders

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.

Sandwich production line has advantages of:
1. Beautiful appearance, low noise, high efficiency
2. Multiple function: In addition to corrugated sandwich panels, this line can be used to produce simple corrugated sheets, and model XBJ-â… & XBJ-â…¡ sandwich panels.
3. The transmission of the laminating system is achieved by worm and worm gear which make the laminating speed smooth and steady.
4. The line employs advanced PLC and sets the length and cuts the panel automatically.
5. The main body is welded with type [H" section steel as its material. The surface is treated by rotoblast.
6. Rollers of the laminating system are covered with rubber, which is advantageous to the protection of the surface color of galvanized sheets and makes the equipment laminate steadily.


Specifications:

Panel width
950, 970,1150mm 
Panel thickness
50-200mm
Raw material
Galvanized coils, Pre-painted coils, Aluminum coils
Material thickness range
0.3-0.7mm
width
1000mm, 1250mm
yield strength
235Mpa
Max coil weight
5000kgs
working speed 
0-5m/min (adjustable)
Total length
about 35m
Control mode
PLC
Total power
about 30kw
Electricty condition 
380v/3phase/50hz (or depend on custmers requirement)


Working process:

Working process


Pictures for machine:

EPS sandwich panel production line  EPS sandwich panel production line

EPS sandwich panel production line  EPS sandwich panel production line

EPS sandwich panel production line  EPS sandwich panel production line



Training and Installation :
1. We offer installation service local in paid, reasonable charge. 
2. QT test is welcome and professional.
3. manual and using guide is optional if no visiting and no installation. 


Certification and after service:

1. Match the technology standard, ISO producing certification 
2. CE certification 
3. 12 months warranty since the delivery. Board. 


Our advantages:

1. Short delivery period. 
2. Effective communication 
3. Interface customized. 

Sandwich Panel Production Line

Sandwich Panel Production Line,Pu Sandwich Panel Production Line,Sandwich Wall Panel Production Line,Eps Sandwich Panel Production Line

YingYee Machinery and Technology Service Co.,Ltd , http://www.yingyee.cn