What are the reasons for the leakage of the tube plate of the column tube heat exchanger?

　　Pharmaceutical Network Technical Article : Recently, there are users said that the tube plate of the column tube heat exchanger has leaked phenomenon, this is how to cause it?
Some manufacturers pointed out that the leakage of tube heat exchangers is generally common to users in the use of equipment management problems, leakage is mainly caused by corrosion, in part due to heat exchanger selection and heat exchanger itself manufacturing process defects
According to the introduction, there are two kinds of corrosion forms of column-tube heat exchangers, one is electrochemical corrosion and the other is chemical corrosion
Factory technical personnel pointed out that the column tube heat exchanger in the production, pipe plate and column tube welding generally use manual arc welding, weld shape there are different degrees of defects, such as depression, pores, slag, weld stress distribution is not uniform When used, the tube plate part is generally in contact with industrial cooling water, and industrial cooling water impurities, salts, gases, microorganisms will constitute corrosion of the tube plate and welds, which is a common electrochemical corrosion phenomenon
The complexity of metal structures also affects corrosion patterns Therefore, the corrosion of tube plate and column pipe weld is mainly hole erosion and gap corrosion Viewed from the outside, there will be many corrosion products and deposits on the surface of the tube plate, with pits of varying sizes
Chemical corrosion is the corrosion of the medium, when the heat exchanger tube plate comes into contact with a variety of chemical media, it will be subject to the corrosion of the chemical medium
In addition, the heat exchanger tube plate and the heat exchanger pipe will also produce a certain amount of bimetallic corrosion Some tube plate because of long-term corrosion medium erosion, especially fixed tube plate heat exchanger, its tube plate and heat exchanger connection is prone to leakage, resulting in the failure of the heat exchanger
Specifically, there are five main factors affecting the corrosion of the heat exchanger tube plate First, the composition and concentration of the medium: the effect of the concentration is different, for example, in hydrochloric acid, the larger the general concentration of corrosion more serious Carbon steel and stainless steel in the concentration of about 50% of sulfuric acid corrosion is serious, and when the concentration increased to more than 60%, corrosion but a sharp decline; The fifth is the flow rate: in most cases, the greater the flow rate, the greater the corrosion
So, how to avoid the phenomenon of corrosion of equipment tube plate? It can generally be divided into two aspects First, when the user selects the equipment, it is necessary to pay attention to whether the quality of the column tube heat exchanger is good and the structure is reasonable, observe the welding oil pollution defects, weld stress is uniform, etc ;
Among them, the maintenance of column tube heat exchanger equipment requirements include: to keep the outside of the equipment clean, insulation layer, protective layer intact, not damaged; In addition, it is necessary to minimize the number of heat exchangers open and stop, stop using the internal liquid should be cleared to prevent freezing and corrosion