Failure Analysis of the Head of Phenol Crystallization Evaporator

内容

Assessment of the Failure of the Head of Evaporating Crystallizer of Phenol

Introduction

This literature aims to analyze the failure of the head of a phenol evaporating crystallizer. Recently, the phenomenon of malfunctions in evaporating crystallizers has attracted attention among researchers in the field of industrial process control technology. The operation of crystallizers is usually divided into two stages, namely settling and collecting stages, which involves the redistribution of the particles within the continuous crystallizing phase, as well as the separation of the crystals from the liquid suspension. Evaporating crystallizers are used in industrial processes where the concentration of dissolved substances need to reached through vaporization. In view of the aforementioned information, this literature will discuss the failure of the head of a phenol evaporating crystallizer and potential approaches for resolving the issue.

Theory

An evaporating crystallizer is a type of process unit used for the production of substance crystals from a liquid solution suspended in the liquor. The unit consists of the crystallizer vessel itself and a separate head, which is designed to store the contents of the evaporator vessel, and furthermore to hold the product crystals at the outlet of the crystallization vessel. Due to the extreme temperatures and pressures within the crystallizer head, it is subject to significant stress on a regular basis, as well as to corrosive attack. The phenol evaporating crystallizer was fitted with a conventional, steel-made head. The head was intended to contain and control the high temperature and pressure in the crystallizer unit while allowing access to the process liquor and the product crystals overflowing from the crystallizer.

Analysis

The failure of the head of the phenol evaporating crystallizer, which is intended to store the contents of the evaporator vessel and keep the product crystals at the outlet of theCrystallizer vessel, was caused by corrosion. This was due to exposure to the high temperature and pressure occurring in the crystallizing system, which compromised the structural integrity of the steel head and allowed corrosive attack to take place, leading ultimately to its complete breakdown. In addition, the severity of the corrosive attack was further augmented by the presence of other impurities in the evaporation liquor, such as oxygen, ammonia, water and carbon dioxide.

Conclusion and Recommendations

In conclusion, this literature discussed the failure of the head of a phenol evaporating crystallizer, which was exposed to high temperature and pressure and was consequently susceptible to corrosive attack. The stainless steel head was subject to the impurities present in the evaporator, leading the rapid corrosion of the head and ultimately its total failure. Consequently, it is recommended that in order to prevent corrosion, the crystallizer should be fitted with a corrosion-resistant head, such as titanium alloy, which is resistant to both high temperature and corrosion and is therefore ideal for evaporating crystallizing operations. Moreover, corrosion inhibitors should also be used in order to reduce the impact of impurities on the crystallizer head.

Phenol crystallizer evaporator head failure analysis

The failure of a phenol crystallization evaporator head can be caused by a variety of reasons. It is important to identify the cause of the failure in order to solve the problem.

In a phenol crystallization evaporator, the head can fail due to corrosion of the inner surface. If the material in contact with phenol is not corrosion-resistant, corrosion can occur over a period of time. This will lead to the formation of holes and cracks, which can cause the evaporator head to fail.

Another potential cause of failure is poor maintenance of the evaporator. The head of the evaporator needs to be regularly checked and maintained in order to ensure it is performing properly. Poorly maintained components can fail or leak. This can cause the evaporator to not work correctly or at all.

Incorrect operation of the evaporator can also cause the head to fail. If the evaporator is not operated correctly, the pressure inside can become too high, which can lead to the failure of the head. This can be caused by incorrect settings or incorrect use of the evaporator.

To determine the cause of the failure, it is important to inspect the evaporator and all its components. This can be done through visual inspection and testing. If any damage is found, repairs can be made. If the cause of the failure is found to be corrosion, it is advisable to replace the corroded parts with components that are more resistant to corrosion.

If the failure is due to poor maintenance, regular maintenance should be done to ensure the evaporator is working correctly. Additionally, it is important to educate personnel on correct operation of the evaporator. This will help to prevent incorrect use or incorrect settings, which can lead to failure of the evaporator head.