Safety and processing

All process equipment has procedures to operate and meet safety requirements. They include a checklist that includes preparation (moving material, etc.), startup and shutdown procedures, tooling changes, and to cleanup of all equipment. Most equipment generates high heats and pressures. They are built to run safely, but they must be treated with respect . 

With plastics that decompose, there may be hazards such as personal bums or wounds and air contamination. Faulty controllers and/or freeze-off can cause the overheating situation from a burned out heater. Safety devices should be used that alert the plant when problems develop people have to be aware of these possible situations. Recognize that personnel injury in plants due to machinery represents 10% of all accidents (Fig. 8-77). 

Thermoplastics Mechanical Fasteners Adhesives Spin and Vibration Welding Thermal Welding Ultrasonic Welding Induction Welding Remarks 

Processing equipment has standard procedures to operate and meet safety requirements. Safety information and standards are available from various sources that include the equipment suppliers, Society of Plastics Industry (SPI), and American National Standards Institute (ANSI). For the past century we have observed increasing activity on the 

Examples of safety features are many and differ for the different equipment in the lines. Safety interlocks ensure that equipment will not operate until certain precautions have been taken. Safety machine lockout procedures are set up for action to be taken in 

---

The ethylene-based, balanced vinyl chloride process, which accounts for nearly all capacity worldwide, has been practiced by a variety of vinyl chloride producers since the mid-1950s. The technology is mature, so that the probabiUty of significant changes is low. New developments in production technology will likely be based on incremental improvements in raw material and energy efficiency, environmental impact, safety, and process reUabiUty. 

Audit Process Audits in the chemical process industry can be focused on process safety, process safety management, environmental, and health areas. The discussion in this section will focus on the process safety and process safety management area, but it should be recognized that the process can be applied to the other areas as well. "Process safety audits are intended to provide management with increased assurance that operating facilities and process units have... 

An interesting and extremely successful primer innovation was introduced by Eley and is known as Eleyprime. Instead of using lead styphnate, with its inherent safety and processing difficulties, Eley uses calculated amounts of lead monoxide and styphnic acid which are much safer to process. At the end of the processing stage a drop of water is added to each individual primer which initiates a chemical reaction between the lead monoxide and the styphnic acid to form lead styphnate. The final product when dry is no different from a conventional primer. 

Even though there appears to be no correlation between occupational safety and process safety performance (Elliott et al., 2008), process safety improvement efforts need to follow the same philosophical directions as the above example— collect the proper information and devise improvement plans. Capturing the commitment of employees and modifying culture can be difficult until employees actually see and understand the benefit from the efforts. 

For aU processes, provide the four levels of control with (1) the basic control system, (2) an alarm system, (3) a safety interlock system (SIS), and (4) a relief system. Related topics are discussed in Section 16.6 and the chapters on safety and process control. 

However, drawbacks are the required high energy use as well as the toxicity and explosivity of ozone and ozonides. In past times, and also today, proposals for the improvement of safety and process control of ozonolysis have been claimed [28-31]. The carbonyl oxide is converted with water into a hydroperoxide, which reacts to an aldehyde and hydrogen peroxide [32]. The latter is used for the subsequent oxidation of the aldehyde group to the carboxylic acid group. It is claimed that an avoided formation of secondary ozonides makes the process safer and diminishes the amount of side products. 

The lack of a simple correlation between occupational safety and process safety was highlighted in the Baker report to do with the 2005 explosion at BP s Texas City refinery (Baker, 2007), one section of which states ... 

Interlocks are commonly used safety devices. The function of an interlock is to prevent the occurrence of an event in the piesraice of certain conditions. Some interlocks prevent action or motion, others send signals to other devices that prevent the action or motion. They automatically reconfigure or interrupt final control devices if monitored variables deviate significantly from specifications. Typical process variables monitored are flow, pressure, level, and temperature. Typical machine variables monitored are coolant level and temperature, lubricant level and temperature, vibration, speed, etc. Interlocks allow equipment to start and operate only when monitored variables are within designed specifications. Interlocks inhibit unanticipated actuation of equipment and ensure correct startup/shutdown sequences are followed. A permissive interlock will not allow a process or equipment to startup unless certain conditions are met. There ate two types of interlocks—safety and process interlocks. Each serves a different function. 

---