Attention should be paid to issues when using a reverse flow

Attention should be paid to issues when using a reverse flow cooling tower during hoisting

 

1. The difference between conventional counter current cooling towers

 

① The water spray density is as high as 16.5m3/(m2 · h), while the water spray density of conventional counter current cooling towers generally does not exceed 12m3/(m2 · h). A higher water spray density not only reduces the cost of circulating water, but also reduces the footprint of the lifting tower under the same output.

 

② The gas to water ratio is only 0.66 (the gas to water ratio of conventional counter current cooling towers is often around 1.2), resulting in low wind resistance and energy consumption.

 

2 issues to be noted

 

① Distance between buildings

 

The "Design Specification for General Layout of Petrochemical Enterprise Plant Areas" has clear regulations on the distance between cooling towers and other buildings. In situations where land is tight, the minimum spacing is usually arranged. However, lifting type counter current cooling towers should not be arranged at the minimum spacing. This is because, if arranged according to the minimum spacing specified, the distance between the suspended countercurrent cooling tower and other buildings is relatively close, and the impact of water vapor on surrounding buildings is greater.

 

① Pay attention to detecting oil pollution indicators during operation

 

If the oil content in the circulating water is greater than 10mg/L, it will cause great harm to the circulation system, and appropriate treatment measures must be taken.

 

Generally, a collection tank can be used to remove floating oil through overflow, while for insoluble hydrocarbons, surface active agents should be used for emulsification first, followed by cleaning with 10% NaOH solution. If there is a large amount of oil leakage, it is difficult to clean thoroughly. Therefore, in daily testing, it is necessary to closely monitor changes in pollution indicators. If any abnormalities are found, relevant parts should be checked as soon as possible to prevent unnecessary losses caused by a large amount of oil leakage.

 

③ Pay attention to checking for foreign objects on the filter screen during system maintenance

 

There are often plastic bags and other debris on the filter screen at the waterway, which should be removed at any time. It should be noted that before lifting the filter out of the water surface, a long stick or other tool should be used to stir up the debris at the bottom of the filter. After it adheres to the filter, it should be gently lifted to avoid debris (especially plastic products) entering the system through the suction tank and blocking the heat exchanger or nozzle.