Calculation of the discharge volume of a safety valve
Thread Content
The reactor is equipped with a jacket; it is heated with steam before the reaction begins, and cooled with cooling water after the reaction starts. Safety relief valves are installed on the heating and cooling pipelines. How is the amount of fluid to be released calculated? Steam is injected into the jacket at times, while cooling water is used at other times. What is the purpose of installing safety valves? This post was last edited by xh520542 on 2009-2-3 at 15:26
Could you describe the specific process in detail? Such as the steam operating pressure and the cooling water operating pressure. How to switch between heating and cooling? Has the vent valve been controlled via DCS to discharge gas before cooling water is introduced? The size of the safety valve – if it is 3/4\" or 1\", it should be a safety valve for liquid thermal expansion.
The function of this safety valve is to allow the release of an appropriate amount of steam in case the jacket outlet valve is accidentally closed while steam is being supplied to the jacket, or in case the drain valve fails and the outlet becomes blocked.
At least 6 types of overpressure conditions: i) Blockage at the steam or cooling water outlet, resulting in overpressure release; ii) The control valves for steam or cooling water remain fully open, leading to overpressure release; iii) Blockage at the cooling water outlet combined with a continuing reaction, where heat causes the cooling water to expand, resulting in overpressure release; iv) Blockage at the cooling water outlet combined with a continuing reaction, where heat causes the cooling water to boil, resulting in overpressure release; v) Corrosion and cracking of the reactor wall, allowing the medium to enter the jacket, resulting in overpressure release; vi) Corrosion and cracking of the reactor wall, allowing the medium to enter the jacket and react with water, resulting in overpressure release. Each of these can be calculated individually. Last edited by JoeWong on 2009-2-4 06:06]
The discharge volume associated with chemical reactions is the most difficult to calculate; it is necessary to analyze various causes of overpressure, compute the discharge volume for each case, and then take the largest value
This is a liquid thermal expansion safety valve. The operating pressure for saturated steam is 0.5 MPa(G), while the operating pressure for circulating water is 0.3 MPa(G). The diameter of the saturated steam pipeline is DN25, and that of the circulating water pipeline is DN50. The outer diameter of the equipment is Φ1324, and the inner diameter of the jacket is Φ1450. The height of the equipment’s cylinder is 1600 mm. The inlet and outlet temperatures of the circulating water are 32/37 degrees Celsius. Before the reaction starts, the temperature is raised using steam; after the reaction begins, the steam supply is cut off and circulating water is used instead to lower the temperature. The amount of expansion of the circulating water needs to be calculated
Agree to use a “liquid expansion safety valve””