Nanjing Chemical Industry Co., Ltd.
Cooling circulating water system of nitric acid device
The objects of technology improvement are the cooling circulating water systems of the 270,000t/a + 100,000t/a dilute nitric acid device and 6,000t/a concentrated nitric acid device. The dilute nitric acid system is equipped with two 630kW pumps and two 560kW pumps. One large pump and two small pumps are used for operation of one 270,000t/a device, and two large pumps and one small pump are used for operation of two devices. The concentrated nitric acid system is equipped with three 400kW pumps, one in service generally (two in service in the high-temperature period of about one month). After system optimization and adjustment, seven high-efficiency pumps are used. The operating mode of the dilute nitric acid system will be optimized and changed. According to the acceptance results, 6,100,000KWH power can be saved annually through the two systems.
| System Name | Operating Mode | Power Consumption before Technology Improvement (kW) | Power Consumption after Technology Improvement (kW) | Power Saving Rate |
| 270,000+100,000t dilute nitric acid system | 1 device | 170 days in any season | 1,640.9 | 931.8 | 37.4% |
| 2 devices | 90 days in winter | 1,761.7 | 1,081.7 |
| 90 days in other seasons | 1,761.7 | 1,303 |
6,000t concentrated nitric acid system | Operation of two cooling water circulating pumps | 2×401.7 | 2×320 | 20.3% |