Blow cycle

These two reactions take place in cycle basis, as the temperature of the second reaction reaches sufficiently high the steam cycle restarts. Because of the wide temperature range in reality a small amount of carbon dioxide is always present in the water gas. Because of contamination in the air blow cycle a small amount of nitrogen is also present in the water gas. 

Fig. 4-10. Injection blow molding complete cycle, starting with injection molding the preform followed by the blowing cycle.

Dust emissions occur during both the end-of-cycle purge sequence and especially the subsequent clean-blow cycle (required to clean out the tanker). Note ... 

To maximize crystallinity build-up in hot fill/heat set containers, the blow mold temperature used is very high, about 150°C. Internal cooling is used at the end of the blow cycle. By letting air out of the container while the inlet valve stays open, the pressure drops and the incoming air expands adiabatically and cools the inside of the container. Typical pressure while the purging air is on is about 13 bars. The air is introduced through holes drilled in the stretch rod, which point the air to critical areas of the container. 

Relative movement between the parison head and mold is necessary so that parison extrusion can proceed continuously while the mold is closed. This is achieved in many different ways. The mold may be lowered, moved aside laterally, or swung aside on an accurate path. Alternatively, the extruder may be moved while the mold remains stationary. Often, two molds are used in a shuttle arrangement, so that one is open for parison extrusion while the other is performing the blowing cycle. One method of mold movement results in very high production rates. In such machines, generally known as wheel machines, a number of molds are mounted on a rotary table. Movement of the table carries the closed mold away and presents a new open mold to the die head, allowing extrusion to continue. 

With the system fed by a blow tank, it could take a considerable part of the blowing cycle to reach a constant solids flow rate and conveying pressure, so that time was wasted before data gathering could commence under steady-state conditions. 

Carburetted Water Gas Similar to water gas with oil added during steam blowing cycle 500... 

The sulfur slurry that accumulates in the bottom of the settler vessel is periodically withdrawn and pumped through a plate and frame filter press where the sulfur is removed and the filtrate is returned to the process. The filtercake is then water washed and air blown to minimize catalyst losses (not shown). The wash water is returned to the system where it serves as a primary source of make-up water to replace that lost by evaporation. The water wash and air blow cycle are the determining factors in the chemical makeup requirements of the process. A small amount of catalyst concentrate is added after each filtration cycle to replace filtercake losses. It is claimed that no catalyst degradation occurs under normal operating conditions. The only other chemical make-up requirement consists of a small amount of alkaline solution for pH control. 

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