Oil circuit

Find a way to overcome the constraint while still maintaining the areas. This is often possible by using indirect heat transfer between the two areas. The simplest option is via the existing utility system. For example, rather than have a direct match between two streams, one can perhaps generate steam to be fed into the steam mains and the other use steam from the same mains. The utility system then acts as a buffer between the two areas. Another possibility might be to use a heat transfer medium such as a hot oil which circulates between the two streams being matched. To maintain operational independence, a standby heater and cooler supplied by utilities is needed in the hot oil circuit such that if either area is not operational, utilities could substitute heat recovery for short periods. 

The reaction is exothermic, and multitubular reactors are employed with indirect cooling of the reactor via a heat transfer medium. A number of heat transfer media have been proposed to carry out the reactor cooling, such as hot oil circuits, water, sulfur, mercury, etc. However, the favored heat transfer medium is usually a molten heat transfer salt which is a eutectic mixture of sodium-potassium nitrate-nitrite. 

For oil-filled control equipment such as autotransformer starters or oil circuit breakers (BOCBs or MOCBs, Chapter 19), insulating oil should be checked periodically for its insulating properties. Leading manufacturers of this equipment indicate the number of switching operations under different conditions of load and fault, after which the oil must be replaced and these must be followed. 

This practice is usually adopted in oil circuit breakers (BOCBs and MOCBs). In air blast circuit breakers (ABCBs), and SF(, circuit breakers, a resistance is connected in shunt across the contact gap. such that R is introduced in the circuit during the making and interrupting processes only. 

Oil-circuit breaker (2)VCB with a copper-chromium contact SF6-circuit breaker... 

Figure 19.4 Rear view of a bulk oil circuit breaker assembly showing single-break contacts, self aligning cluster Isolating contacts, terminal bushing and arc control pots (Courtesy ...

However, this is an improvized version of the bulk oil circuit breaker. Here, the oil is used only for the purpose of quenching the arc. It became the most sought-after... 

The fact that oil was effective for the extinction of the arc formed between the opening contacts of a circuit breaker was discovered towards the end of the nineteenth century. In a bulk oil circuit breaker the oil is used both as the medium for arc extinction and as the insulating material of the contacts. The contacts are contained within a... 

In a minimum oil circuit breaker only the arc control device is enclosed within an oil-filled housing. This housing is supported and insulated separately to provide the necessary phase clearances between phase connections and earth. 

As a replacement for bulk oil circuit breakers for distribution purposes, vacuum is a rival to SFg. The contact interruption chamber is a sealed unit with a small contact-separation distances (typically, 16mm for 24kV). Choice of contact material is critical since the material affects ... 

A problem table heat cascade for A Tmm = 10°C is given the Table 18.15. Hot utility is to be provided by a hot oil circuit with a supply temperature of 400°C. Cooling water is available at 20°C. 

The crude phthalic anhydride is heated and held at 260°C to allow some byproduct reactions to go to completion. Purification is by continuous distillation in two columns. In the first column, maleic anhydride and benzoic and toluic acids are removed overhead. In the second column, pure phthalic anhydride is removed overhead. High-boiling residues are removed from the bottom of the second column. The reboilers of both distillation columns are serviced by a fired heater via a hot oil circuit. 

The hot oil to the kettle boiler is a circulating pumparound stream, from a fluid catalytic cracker fractionator, slurry-oil circuit. There is a fundamental difference between this sort of boiler and the utility plant boilers discussed previously. In the kettle boiler, the heating medium is inside, rather than outside, the tubes. To obtain the full capacity of... 

Fig. 2.30. Simplified P. I diagram of liquid nitrogen. 1, Chamber and shelves 2, condenser 3, silicone oil circuit 4, heater 5, heat exchanger.

Fig. 2.63. CIP principle. 1, Chamber 2, condenser 3, chamber-condenser valve 4, hydraulic stoppering system 5, silicone oil circuit 6, cooling system 7, vacuum system ...

Site drainage waters from surface runoff invariably include some oil picked up from small spills and process leaks. These will also be routed through an API separator first, sometimes followed by a dissolved air separator (Fig. 18.8). Oil separated from this drainage water stream will join the slop oil circuit for recycling. During times of desalter operation when water is short, treated site drainage waters may be used for this purpose. Any water in excess of desalter requirements will proceed to an artificially aerated bio-pond for further BOD reduction before discharge [74]. 

Metal-clad switchgear equipment with air or oil circuit breakers should be selected for (1) starting and controlling motors for operation above... 

BS116 Oil circuit breakers (for alternating current systems above 1 kV)... 

DAC column equipped with high-pressure valves in the two lines of the hydraulic oil circuit, which are closed during normal use of the column. After the process is finished and the gas pressure has been released from the column, the valves in the oil circuit can be opened and the oil pump activated to compensate for an eventually created void volume during the process. Thereafter, both valves are closed again and the column is ready for further use. 

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