174、description of fire fighting and telecommunication system of large ethylene cryogenic full capacity tank -威尼斯2299

description of fire fighting and telecommunication system for large ethylene cryogenic full tank

description of fire fighting and telecommunication system for large ethylene cryogenic full containment tank:

1. fire fighting system

（1） spray cooling device

the tank is equipped with a set of spray cooling fire fighting device, which is composed of pipeline, sprinkler and water supply riser. the system is set at the tank top, tank wall, stairs, safety passage and important process instrument equipment, and the setting of the system conforms to the relevant domestic specifications.

the fire sprinkler pipes of storage tanks are 20# seamless double-sided galvanized steel pipes, and the device adopts the overall anti-corrosion method. the device is prefabricated, welded and formed, and then acid pickling and hot-dip internal and external galvanizing and anti-corrosion treatment are carried out as a whole, so as to achieve the anti-corrosion of the whole product without blind area.

the arrangement spacing of the spray head meets the requirement that the fan-shaped water curtain ejected by the spray head intersects the tank wall to prevent blind area;

decompression facilities are set at the main pipe entrance of the sprinkler to control the inlet pressure. the outlet pressure, outlet coefficient and piping of the sprinkler meet the requirements that the actual water spraying volume after installation shall not exceed 5% of the calculated water volume; the water spraying intensity shall be no less than 4l / min. m2for the top of the tank and no less than 2.5l/min.m2 for the wall of the tank.

（2） fire alarm system

(1) according to the standard for construction and acceptance of automatic fire alarm system (gb 50166-2019), relevant product instructions and

the system diagram and the scene situation, the correct connection between the alarm system.

(2) alarm control settings:

three flameproof three wavelength infrared flame detectors with 4-20ma output and standby switch signal are set around the vent pipe;

the location of leakage from tank top to flare pipe is: 6 flame-proof combustible gas detectors; 4-20ma output, standby switch signal;

the tank top is equipped with two platinum thermistors (the platinum thermistors are symmetrically arranged), the explosion-proof instrument control terminal box at the tank bottom is equipped with modules, and the switching value signal output.

2. monitoring facilities

one set of explosion-proof integrated camera (2 sets, 1 cloud type and 1 direct type) is set on the ethylene tank top, with far-infrared night vision function to monitor the tank top fire and other dangerous situations, so that the production personnel can more intuitively understand the operation status of the process unit. the design, installation and fixation of the camera shall be determined through negotiation with the buyer.

3. other safety devices

combustible gas leakage detection: combustible gas leakage detector is set on the top platform of the storage tank, and the output signal is 4 ~ 20ma.

lightning protection grounding: the storage tank is connected to the lightning protection grounding grid of the whole station.