최근 텍사스 패서디나 시는 몇 년 동안 시달려온 우수 범람 문제를 해결하기 위해 덴마크 기반의 펌프 제조업체인 Grundfos사의 제품인 Axial-Flow 수중 펌프 라인으로 펌프를 교체했다.

엄청난 폭우 동안 패서디나시는 펌핑 스테이션을 빠르게 압도하는 과도한 유량을 가져야 했다. 가장 문제였던 것은 그 엄청난 유량이 허리케인 발생시 대피 루트를 막는 장애의 원인이 될 수 있다는 것이다. 이러한 문제 때문에 집중호우 때 시의 주요 우선순위는 대피 루트를 비우고 통행가능하게 유지하는 것이었다.

 

 

 

Recently, officials of the city of Pasadena, Texas, along with the Texas Department of Transportation (TDOT) turned to Grundfos, a Denmark-based pump manufacturer, and its line of Axial-Flow Submersible Pumps to solve a major flooding issue that had plagued the city for years.

 

During significant rainstorms, Pasadena receives excessive water flow that quickly overwhelms its pumping stations. Most alarmingly, ample flow can cause blockage that affects hurricane evacuation routes. Because of this, the city's main priority during major storms is to keep the routes clear and passable.

 

 Beltway 8 is one of the few main highways used to evacuate residents from the south and southwest during a hurricane. For decades, the Spencer Road exit has suffered from surface water flooding. On several occasions, the designated evacuation route was left impassable. In cooperation with TDOT, Pasadena was able to determine that the cause of the flooding was insufficient capacity of the storm drain system. In these systems, flap gates are installed at or near drain outlets to prevent the drainage system from back flooding during major storms.

 

In the case of Beltway 8, the road's 54-inch storm sewer lacked proper capacity, so a flap gate valve would prevent additional water from flowing back on the road. Problematically, however, that same safety valve would also limit flow into the drain, causing frequent flooding to the roadway that would result in lane closures and extended traffic delays.

 

 Pasadena had two options. It could either create a large detention basin or it could increase the capacity of the storm system. Both options required several million dollars, as well as the allocation of real estate and years of construction.

 

 "The particular application of this stormwater pump system was unique in that it was placed between the Texas Department of Transportation feeder roads and the Harris County Toll Road Authority main lanes in a footprint that most engineers would consider daunting," said Mark Gardemal, assistant director of Public Works for Pasadena. "We had about 25 feet to work, and we were going to have to do all our pumping and piping arrangements below ground."

 

 Because of restrictions on space, project engineers reconsidered their initial two options. Instead, they decided to route excess stormwater around the existing sewer and push it far enough downstream to create adequate capacity.

 

 "We recommended the Grundfos submersible pumps along with the CU362 and the variable frequency drive," said Cory Marcotte, engineering sales professional at distributor Pumps of Houston. "It allows us not only to maintain high efficiencies during operation but also to monitor and adjust the speed of the pump depending on how much rainfall we get at a particular time."

 

 The energy-efficient line is capable of pumping up to 150,000 gallons per minute and features a compact design, as well as construction cost savings of up to 50 percent. The Grundfos stormwater pumping station offered project planners a compact, energy-efficient and cost-saving solution, which for Pasadena, saved significant operation and maintenance costs when compared to similar options.

 

 Since the city installed the pumps in 2012, the area experienced a major storm that generated 6 inches of rain. Amid fears of flooding, the new pumping station efficiently moved more than 30,000 gallons of flood water per minute for roughly five hours -- keeping the highway clear and safe.

 

[출처 = Water World / 2014년 11월 17일]