Deaerators systems

Conversely, larger and higher pressure boilers tend to employ mechanical deaeration systems and supplement this by using a smaller quantity of oxygen-removing chemical as a true scavenger. This is added to the base of the deaerator (the deaerator storage section). 

The equipment feed design consisted of a funnel-shaped powder hopper (with no vacuum deaeration system) that was located directly above the rolls. The powder hopper was retrofitted with vacuum deaeration capability. A high compression feed screw, fitted inside the funnel hopper, fed the powder directly into knurled rolls. The compaction trials were conducted with and without vacuum deaeration. The compact was carefully collected directly on a 10-mesh screen. Powder particles, that were not compacted (i.e., those particles which were not attached to the compact, for example, fines bypassing roll compaction and the non-adhering compacted powder particles) were weighed and separated. The compact was not milled. The parameters are noted in Table 4. 

In several other trials, Miller also studied the effects of using two different compactors vacuum deaeration systems. The tests, similar to the ones previously described in this section, were carried out using differently designed compactors (employing and not employing vacuum deaeration). The objective of these trials was to increase the active bulk density of the feedstock from 0.22gcm to 0.61 gcm. ... 

A specially designed compression feed screw and upper arm assembly are shaped to closely conform to the inner wall of the feed hopper. The feed screw (usually non-cylindrical) has uniquely pitched edges. The feed screw design features and gravity aid to drive the powder-stock into the compaction area. There is no vacuum deaeration system. Predensifica-tion and deaeration occur in the screw feed region during operation. 

Table 3.5 Comparison between a Higrav deaerator (two sets, 6000td ) and a vacuum tower deaeration system (one set, lOOOOtd ) for off-shore application. Source adapted from Stankiewicz [98] and Zheng et al. [103].

Aeration can be a major problem for pumping 70% SLES. Aeration occurs during sulphonation. Deaeration before neutralisation may lead to an unacceptable increase of 1,4-dioxane due to extra residence time of the acid product in the deaeration system. Therefore deaeration of the paste prior to storage may be preferred. 

The GasTran deaeration system delivered ultra-low dissolved oxygen in the process water, which enabled the bottling line to produce consistent car-bonation to our fill lines, increase plant capacity and improve profitability . Rob Schlafer, Director of Engineering, PepsiAmericas East Group. 

Figure 4 Twin horizontal feed screw system with vacuum deaeration system. (Courtesy of...

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