The Skip-resistant Sprinkler Concept -- Theoretical Evaluation

This article presents a model for the response time of a sprinkler designed to reduce the skipping phenomenon experienced during large-scale fires. The model guides the design of a cylindrical shield intended to reduce drop impingement from nearby operating sprinklers. Several designs are experimentally tested and shown to reduce likely skipping when compared to the same sprinkler without a shield. The model is validated using a laboratory Plunge Tunnel apparatus to measure the effect of the shield on the thermal sensitivity of the sprinkler and its ability to intercept water drops. This work successfully demonstrates that shielding can decrease the response time of a sprinkler in drop-laden gas flow without causing a substantial increase in response time when exposed to a dry-gas flow. This is the first of two articles on the skip-resistant sprinkler concept. The following article evaluates the performance of the shield in actual fires.