To ensure a safe and reliable operating environment of LNG storage tanks, the following measures are taken.
(1) Dry powder fire extinguishing device
A skid-mounted fire-fighting dry powder fire extinguishing device is installed on the top of the storage tank, and an explosion-proof three-frequency infrared flame detector and an armored platinum thermal resistance thermometer are installed at the vent of the exhalation (pressure relief) valve. When the temperature of the diffuser tube reaches the set alarm temperature (200°C) and the flame detector sends out an alarm signal, the FGS system outputs a switch signal to activate the dry powder fire extinguishing device. The dry powder fire extinguishing system has three starting methods: automatic control, manual control and mechanical emergency operation.
A pressure switch is installed at the powder outlet of the dry powder skid. When the main dry powder fire extinguishing system is started, the dry powder pressure will be detected. When the pressure is not detected, the main dry powder fire extinguishing system will be deemed to have failed to start, and the control cabinet will automatically start the standby dry powder fire extinguishing system.
The protection level of the explosion-proof control box is IP65, and the explosion-proof level is ExdⅡBT4;
(2) Deluge sprinkler cooling device
The storage tank is equipped with 1 set of deluge sprinkler cooling fire-fighting device, which is composed of pipelines, sprinklers and water supply risers. It is installed on the tank roof, tank wall, stairs, safety passages and around important process instruments and equipment, and the system installation complies with relevant China`s regulations.
The fire-fighting sprinkler pipeline of the storage tank adopts 20# seamless double-sided galvanized steel pipe, and the device adopts the overall anti-corrosion method. The device is prefabricated and welded, and then the whole unit is acid-cleaned and hot-dip galvanized inside and outside to have the blind-zone-free anti-corrosion effect.
The spacing of the nozzles is such that the fan-shaped water curtains sprayed out have a certain intersection on the tank wall to prevent blind spots;
There is a pressure reducing facility at the main entrance of the sprinkler device to control the inlet pressure.
(3) Fire (detection) alarm system
1) In accordance with "Standard for Construction and Acceptance of Automatic Fire Alarm System" (GB 50166-2019), relevant product manuals and System diagram and site conditions, correctly connect the connection between the dry powder fire extinguishing system equipment and the alarm system.
2) Alarm control settings:
Set around the venting tube: 2 explosion-proof three-wavelength infrared flame detectors, 4-20mA output, standby switch signal;
Set at the venting tube: 1 platinum thermal resistance, tank bottom explosion-proof instrument control terminal box setting module, switch signal output (120H, 65L signal dual output);
Set at locations where the venting pipeline is prone to leakage on the tank top: 3 explosion-proof combustible gas detectors; 4-20mA output, standby switch signal;
Set at the tank to: 2 platinum thermal resistors (platinum thermal resistors are arranged symmetrically), tank bottom explosion-proof instrument control terminal box setting module, switch signal output (65L signal dual output).
As a professional one-stop-shop industrial gas solution providers, DOER is becoming widely known for bimetal / steel atmospheric cryogeic full / single containment storage tanks for LNG receiving terminals, reserve centers & peak shaving stations, and also VPSA oxygen plant for boilers, smelters. Focusing on innovation & improvements, DOER always values the customer-driven quality and long term partnership. Contact us now if you're interested in any type of cooperation.