Bursting disk

Thermal runaway is a partieular problem in unsteady state bateh reaetions, where the rate of reaetion and, therefore, the rate of heat produetion varies with time. The eonsequenees of thermal runaway are sometimes severe as in the ineidents at Seveso [3]. In this ease, a bursting disk ruptured on a reaetor. The reaetor was used to manu-faeture triehlorophenol at a temperature of 170-185°C and was heated... 

Ml Ives, burst disks, valves or trips. In addition to hardware systems are human systems such as 1) emergency response, 2) administrative controls,... 

The ruptured or burst disk on a vessel or pipe system presents a pressure drop to flow at that point, and it can be estimated by assuming the disk is a flat plate orifice [37] wdth a discharge coefficient, K[Pg.459]

Pb = stamped bursting disk pressure plus accumulation of 10% plus atmospheric pressure, psia P2 = pressure on outlet side of rupture disk, psia... 

For pipelines, bursting disks have been proven practical, especially when equipped tvith a sensor to pick up the explosion and a detonator to rupture the disks in advance of the pressure wave. The installation of a moveable... 

An autoclave without a bursting disk and containing the two poorly mixed reactants was wrecked by a violent explosion which occurred on heating the autoclave to 180°C [1]. This was attributed to not allowing sufficient free space for liquid expansion to occur [2], The need to calculate separate reactant volumes under reaction conditions for all autoclave preparations is stressed [3],... 

Catalytic hydrogenation on 400 g scale at 34 bar under excessively vigorous conditions (250°C, 12% catalyst, no solvent) caused the thin autoclave without bursting disk to rupture [1]. Under more appropriate conditions the hydrogenation is safe [2], See other catalytic nitro reduction processes... 

A nitration reactor was charged with methanol which was wrongly labeled as xylene. Addition of nitrating acid mixture led to a runaway exothermic reaction which eventually ruptured the reactor as well as the bursting disk, allowing 2700 1 of mixed acid to spray out. 

Dining preparation of an unspecified oxime, the carbonyl compound, pyridine, hydroxylamine hydrochloride and sodium acetate were heated in a stainless steel autoclave. At 90°C a sudden reaction caused a pressure surge to 340 bar, when the bursting disk failed. The reaction had been run previously and uneventfully on one-tenth scale in a glass lined autoclave. 

The inertia, the opening behavior of a bursting disk or of the movable cover of an explosion device, and its arrangement (horizontal, vertical) can affect the venting efficiency and may result in a higher maximum reduced explosion overpressure inside the protected vessel (Fig. 23-13). This venting efficiency is mainly dependent upon the specific mass of the venting device. 

This program contains an example of conditional statements. A conditional variable DISK is defined such that if DISK = 1 then the bursting disk is intact, and if DISK = 0 the disk has burst. The discharge velocity through the disk varies with pressure as given by the complex conditional statement in the partial listing below ... 

Bursting disc control If Disk=l then bursting disk OK if Disk= 0 disk has burst ... 

State of the disk, starts at 1 and decreases quickly after bursting,- the value of Disk is used to detect if the disk has burst. After bursting Disk= 0 d/dt(Disk) = -Fdisk Limit Disk> = 0 I NIT Disk= 1... 

Beveridge, H.J.R. and Jones, C.G., Shock effects on a bursting disk in a relief manifold, in The Protection of Exothermic Reactors and Pressurised Storage Vessels, I Chem E Symposium Series No. 85, pp. 207-14 (1984). 

The pressure of nitrogen and steam produced shears the bursting disk and releases the gases into the shothole. 

Both Cardox and Hydrox devices should be subjected to tests before permission is granted for their use in coal mines, because the essential components of these devices are mixtures similar in nature to explosives. Faulty assembly, such as omission of a bursting disk may bring hot gases in contact with a methane-air mixture or coal-dust. 

Towards 1938 a modification of this method was introduced under the name of the Armstrong Airbreaker [9], In this system the air is compressed up to 800 kg/cm2 and introduced by opening a blow-out valve this ruptures the bursting disk and blows up the shothole. 

The Airdox device is very safe towards methane and coal-dust. Safety is especially increased by the improvement of the bursting disk which is fitted with a plastic plug closing the charge. 

---