There has been reluctance from many iron foundries to adopt naturally pressurized gating systems due to the lack of knowledge on the application of the theories set out by Dr. John Campbell. The applications of naturally pressurized gating systems are still evolving and, in many cases, are counterintuitive to foundry engineers. This research tested proposed gating system behavior during filling, and from the resulting data, velocity losses (friction coefficients) through ceramic foam filters were measured. The verification of the velocity by modeling and simulation of these systems proved relatively accurate in most cases studied. The research concluded that a vertical vortex sprue system had the highest velocity reduction, reducing it by 37% (friction coefficient of 0.63), but had some initial air bubbles travel through the gate before steady-state flow occurred. The most effective gating system tested was a bottom gate and ceramic foam filter combination utilizing a bypass for the initial damaged metal and initial velocity reduction. The in-line gating using 10PPI and 20 PPI ceramic foam filters had a reduction in velocity of 16% and 28%, respectively, but caused major bubbles and jetting of the initial metal at the gate. When using filters in-line with the runner, the filter print and the bypass should be vented and the bypass have sufficient volume to counteract the initial high-velocity metal entering from the sprue. A bypass of sufficient size, reduced the initial velocity of metal through the gate, allowed priming of the filter, eliminated jetting, and reduced the chance of damaged metal from entering the mold.

中文翻译：

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自然压力门控系统的速度测量和验证

由于缺乏约翰·坎贝尔博士提出的理论的应用知识，许多铸铁厂都不愿采用自然加压浇口系统。自然加压浇口系统的应用仍在不断发展，在许多情况下，与铸造工程师背道而驰。该研究测试了建议的浇口系统在填充过程中的行为，并根据所得数据测量了通过陶瓷泡沫过滤器的速度损失（摩擦系数）。在大多数研究的情况下，通过对这些系统进行建模和仿真来验证速度是相对准确的。研究得出的结论是，垂直涡流浇道系统的速度降低最高，降低了37％（摩擦系数为0.63），但在稳态流动发生之前，有一些初始气泡通过了闸门。测试过的最有效的浇口系统是底栅和泡沫陶瓷过滤器的组合，利用旁路对初始损坏的金属和初始速度进行降低。使用10PPI和20 PPI陶瓷泡沫过滤器的在线浇口分别降低了16％和28％的速度，但在浇口处产生了较大的气泡并喷射了初始金属。当在流道上串联使用过滤器时，应对过滤器打印件和旁路进行排气，并且旁路应有足够的容积以抵消从浇口进入的初始高速金属。尺寸足够大的旁路，可降低金属通过闸门的初始速度，允许对过滤器进行灌注，消除喷射，