The vacuum system of the equipment includes 30 vacuum pumps, 50 vacuum valves, 10 anti-oil return baffles (cold traps), a total vacuum pipe length of 500m, and a total power of 740kw. The total water consumption is 65t / h, and the compressed air flow is standard. The maximum is 2.5m3 / min.
In order to simplify the system, reduce floor space, reduce investment and operating costs, the high vacuum unit borrows the booster stage pump and foreline pump of the medium vacuum unit, and the low vacuum unit borrows the booster stage pump of the medium vacuum unit. The on-off of the gas path during the process is controlled by valves to meet the requirements of each unit.
(1) High vacuum system configuration
The ultimate pressure of the equipment is three orders of magnitude lower than the working pressure. It is necessary to solve the problem of parallel connection of medium and high vacuum units. According to calculations, two sets of JK-1200 high vacuum oil diffusion pump + roots pump + slide valve pump are used. Evacuation unit. The ultimate pressure of the unit is 1.4 × 10-4Pa, and the extraction rate is 21000L / S.
(2) Medium vacuum system configuration
The configuration of this system must meet the requirements for the displacement under working pressure. If the cabin pressure is less than 2 Pa when the rocket is ignited, the test results will be inaccurate.
(3) Low vacuum system configuration
Because a large amount of condensable gas generated during the ignition of the rocket engine is captured by the heat sink and deposited in the form of frost in the cabin, and cannot be removed by manual methods, a low vacuum system is specially configured to achieve the slow sublimation of the condensable gas and discharge it. Outside the cabin.
The system uses two sets of double roots pump + water ring pump three-stage evacuation unit to increase the vacuum degree of the unit and make it reach the pressure required for the sublimation of condensable substances. The unit's ultimate pressure is 1 × 10-1Pa, and the air extraction rate is 1200L / s.