How is the pressure of the 6.5 MPa flash system in Texaco gasification controlled?

The concentrated black water at the bottom of the evaporation chamber of the evaporative hot water tower (148.6 m3/h, 175.25°C, 0.8 MPa) is discharged from the bottom side through the level control valve LV1304 and enters the low-pressure flash tank (V1303) for further flashing. The flash vapor (5111.7 m3/h, 139°C, 0.25 MPa) is sent to the deoxidation tank (V1307) for deoxidization. The concentrated black water from the low-pressure flash tank (132.6 m3/h, 139°C, 0.25 MPa) enters the vacuum flash tank (V1304) via the level control valve LV1306. The sludge-containing water from the sludge tank (V1208) is pumped by the sludge tank pump (P1203), passing through the flow control valve FV1214 (55 m3/h, 85°C, 0.45 MPa), and sent to the vacuum flash tank (V1304). The black water undergoes vacuum flash evaporation in a vacuum flash evaporator; a large amount of vapor (51084 m3/h, 78.87°C, -0.056 MPa) is released, causing the black water to become more concentrated, with an increased solid content and a further drop in temperature. After being cooled in the vacuum flash cooler (E1303), the flash vapor is sent to the vacuum flash separator (V1305). The flash vapor exiting from the top of the separator (429.5 m3/h, 71.5°C, -0.067 MPa) is directed to the water ring vacuum pump (P1301), and the material at the outlet of the vacuum pump is discharged into the atmosphere. The condensate at the bottom of the vacuum flash separator (14.5 m3/h, 71.53°C, -0.067 MPa) is sent to V1309 by the vacuum flash condensate pump (P1310) via the level control valve LV1308. The black water at the bottom of the vacuum flash tank (159 m3/h, 78.87°C, -0.056 MPa) is pressurized by P1309 and then sent to the static mixer (X1302) via the level control valve LV1307. There, it mixes with the flocculant coming from the flocculant tank (V1310), which has been pressurized by the flocculant pump (P1305; 0.32 m3/h, 30°C, 0.9 MPa), before flowing into the sedimentation tank (V1308).

The concentrated black water at the bottom of the evaporation chamber of the evaporative hot water tower (148.6 m3/h, 175.25°C, 0.8 MPa) is discharged from the bottom side through the level control valve LV1304 and enters the low-pressure flash tank (V1303) for further flashing. The flash vapor (5111.7 m3/h, 139°C, 0.25 MPa) is sent to the deoxidation tank (V1307) for deoxidization. The concentrated black water from the low-pressure flash tank (132.6 m3/h, 139°C, 0.25 MPa) enters the vacuum flash tank (V1304) via the level control valve LV1306. The sludge-containing water from the sludge tank (V1208) is pumped by the sludge tank pump (P1203), passing through the flow control valve FV1214 (55 m3/h, 85°C, 0.45 MPa), and sent to the vacuum flash tank (V1304). The black water undergoes vacuum flash evaporation in a vacuum flash evaporator; a large amount of vapor (51084 m3/h, 78.87°C, -0.056 MPa) is released, causing the black water to become more concentrated, with an increased solid content and a further drop in temperature. After being cooled in the vacuum flash cooler (E1303), the flash vapor is sent to the vacuum flash separator (V1305). The flash vapor exiting from the top of the separator (429.5 m3/h, 71.5°C, -0.067 MPa) is directed to the water ring vacuum pump (P1301), and the material at the outlet of the vacuum pump is discharged into the atmosphere. The condensate at the bottom of the vacuum flash separator (14.5 m3/h, 71.53°C, -0.067 MPa) is sent to V1309 by the vacuum flash condensate pump (P1310) via the level control valve LV1308. The black water at the bottom of the vacuum flash tank (159 m3/h, 78.87°C, -0.056 MPa) is pressurized by P1309 and then sent to the static mixer (X1302) via the level control valve LV1307. There, it mixes with the flocculant coming from the flocculant tank (V1310), which has been pressurized by the flocculant pump (P1305; 0.32 m3/h, 30°C, 0.9 MPa), before flowing into the sedimentation tank (V1308).