Discharge systems

Reaetors or storage vessels are fitted with an overpressure proteetion vent direetly to roof level. Sueh deviees (e.g. relief valves) proteet only 

The method includes the mass unit vent flow capacity per unit area. G. This allows using any applicable vent capacity calculation method. The method incorporates the equilibrium rate model (ERM) for vent flow capacity when friction is negligible. Additionally, a coiTection factor is used for longer vent lines of constant diameter and with negligible static head change.  

The heat evolution rate per unit mass, the vent capacity per unit area, physical properties (e.g.. latent heat of liquid, specific heat, and vapor/liqnid specific volumes) are constant. It allows for total vapor-liqnid disengagement of fluids that are not natural surface active foamers.  

A hand calculation method that can be used to take into account two-phase relief when the materials m the vessel are natural surface active foamers. To account for disengagement, the vessel void fraction at disengagement should be evaluated (i.e.. the point at which the vent flow ceases to be two-phase and starts to be vapor only).  

The method uses the dnft-fhix level swell calculation models to take into account there being more vapor in the inlet stream to relief device than average for the vessel. 

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Another approach to the control of batching systems is to use a relatively simple scale indicator which does nothing but supply weight data to a controUer such as a PLC, which in turn controls the fiH and discharge system. The communications between the scale and controUer can be serial such as RS-232, or it can be an analogue signal such as 4-20 m A. While this system minimises operator interaction with the scale, it sacrifices speed and accuracy because of the relatively slow communications. 

The patented system (15) has stationary disks mounted inside a pressure vessel (horizontal vessel, vertical disks) which is mounted on rollers and can rotate slowly about its axis. A screw conveyor is mounted in the stationary center of rotation it conveys the cake, which is blown off the leaves when they pass above the screw, to one end of the vessel where it falls into a vertical chute. The cake discharge system involves two linear sHde valves that sHde the cake through compartments which gradually depressurize it and move it out of the vessel without any significant loss of pressure. The system rehes entirely on the cake falling freely from one compartment to another as the valves move across. This may be an unrealistic assumption, particularly with sticky cakes when combined with lots of sliding contact surfaces which are prone to abrasion and jamming, the practicality of the system is questionable. 

Fig. 12. (a) Typical-feeding and (b) discharge systems for endless-belt cooling of molten materials. Courtesy of Sandvik Process Systems Canada Ltd. 

Sludge discharge systems should allow for easy automation and variation of volumes discharged. Mechanical scraper tip speed should be less than 1 m with speed variation of 3 1. 

Superimposed Back Pressure - Is the pressure at the outlet of the pressure relief valve while the valve is in a closed position. This type of back pressure comes from other sources in the discharge system it may be constant or variable and it may govern whether a conventional or balanced bellows valve should be used in specific applications. 

Built-up Back Pressure - Is the frictional pressure drop that develops as a result of flow through the discharge system after the pressure relief valve opens. 

Conventional PR valves and discharge systems should be designed such that built-up back pressure does not exceed 10% of set pressure (both measured in psig), to avoid chattering problems. In the case where a pressure relief valve system is sized for fire conditions, with 21 % overpressure, built-up back pressure up to 21 % of set pressure is permissible. However, the lower rates resulting from other contingencies still must meet the 10% limitation. 

Back Pressure - The combined atmosphere discharge system must be designed to comply with the superimposed back pressure limitations. 

Fatigue Failure - The combined discharge header system should be designed in accordance with the same considerations of potential piping fatigue failure as described below for closed discharge systems. 

Superimposed back pressure The static pressure existing at the outlet of a pressure relief device at the time the device is required to operate. It is the result of pressure in the discharge system from other sources. 

The Select Industrial Discharge System (SIDS) assists exposure assessors and other analysts by consolidating current data contained in various EPA water-related environmental information... 

Discharge systems are used to discharge exhaust air to the outdoors in such a way that harmful spreading of pollutants to the environment and back indoors is avoided. 

Discharge system A system that discharges unwanted gaseous, solid, or liquid products. 

The species H2 and H3+ are important as model systems for chemical bonding theory. The hydrogen molecule ion H2+ comprises 2 protons and 1 electron and is extremely unstable even in a low-pressure gas discharge system the energy of dissociation and the intemuclear distance (with the corresponding values for H2 in parentheses) are ... 

The designer must examine the specific valve selected for a service and evaluate the materials of construction in contact with the process as well as in contact or exposed to the vent or discharge system. Sometimes the corrosive... 

Safely Volve Required to Protect Against Closed Block Valve Anywhere in Discharge System. 

Discharge systems—to by provide close control of metal buildup. 

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