Chemical apparatus and process disinfecting – deodorizing – preser – Chemical reactor – Including solid – extended surface – fluid contact reaction...
Patent
1991-05-30
1993-02-02
Kummert, Lynn M.
Chemical apparatus and process disinfecting, deodorizing, preser
Chemical reactor
Including solid, extended surface, fluid contact reaction...
422200, 422207, 422217, 422234, 110216, 196110, 196122, 196140, 208130, B01J 808, C01G 936
Patent
active
051836424
DESCRIPTION:
BRIEF SUMMARY
The invention relates to an installation for steam cracking hydrocarbons, with solid erosive particles being recycled.
Proposals have already been made to decoke an installation for steam cracking hydrocarbons by means of solid erosive particles of fine grain size, which particles are injected into the feedstock of hydrocarbons to be cracked, with a centrifuging cyclone being used to separate the particles from the gaseous effluent either on leaving a cracking furnace or on leaving an indirect quench heat exchanger itself placed at the outlet from the cracking furnace. The level of the solid particles recovered in this way is then raised so that the particles can be reinjected upstream from the cracking zone by means of an ejector producing a high-speed flow of gas. It may therefore happen that the solid particles give rise to relatively rapid and significant erosion of the recycling means, requiring specially designed equipment to be used (having anti-abrasion coatings) which is expensive and may nevertheless have a short lifetime.
A particular object of the invention is to avoid this drawback and to enable solid particles to be recycled using means of ordinary design or of long lifetime.
Another object of the invention is to make it easy to regulate the flow rate of recycled solid particles through the steam-cracking installation, thereby ensuring high reliability of the decoking means with respect to the integrity of the equipment.
Another object of the invention is to prevent traces of liquid causing the solid particles to stick together when being separated or recycled.
To this end, the present invention provides a hydrocarbon steam cracking installation comprising at least one furnace for cracking hydrocarbons, an indirect quench heat exchanger for the effluent leaving the furnace, and direct quench means for the effluent, together with means for injecting a low flow rate of solid particles into the furnace and means, such as a cyclone for separating solid particles from the gaseous steam-cracking effluent, which means are placed between the indirect quench heat exchanger and the direct quench means, the installation being characterized in that it includes a tank for storing solid particles, with the inlet of the tank being connected to the solid outlet from the cyclone and with the outlet of the tank being connected to a particle injection duct for injecting particles into the installation, isolation means such as valves for isolating the tank, and a source of gas under pressure connected to the particle injection duct and to the tank by means such as a valve for increasing the inside pressure of the tank to a value that is not less than the pressure at the point at which particles are injected into the furnace.
The solid particles are thus injected discontinuously into the furnace while it is in operation. The above-mentioned tank serves to store the solid particles during the non-decoking stages during which particles are not injected. Thereafter, because the static pressure inside the tank can be increased, the solid particles are easily raised to a sufficient pressure and recycled in the form of a solid suspension in a dilute phase to the point where they are injected into the steam-cracking installation and without it being necessary to use a very high speed flow of vector gas. This greatly reduces the erosion of the means for recycling the solid particles.
In addition, the source of gas under pressure providing the vector gas flow also serves to increase the pressure inside the solid particle storage tank. Because of the pressure equilibrium obtained in this way, excess pressures that could compact the solid particles or that could cause the particles to be ejected too suddenly from the tank are avoided.
According to another characteristic of the invention, the installation includes an intermediate tank connected between the outlet from the cyclone and the inlet to the first-mentioned tank, and isolation means such as valves for isolating said intermediate tank.
This intermediate tank serves t
REFERENCES:
patent: 2483494 (1949-10-01), Kleiber et al.
patent: 2985324 (1961-05-01), Balentine
patent: 3215505 (1965-11-01), Schmalfeld et al.
patent: 3729105 (1973-04-01), Huebler et al.
patent: 4205196 (1980-05-01), Makovec et al.
patent: 4245571 (1981-01-01), Przewalski
patent: 4477413 (1984-10-01), Carson
patent: 4655147 (1987-04-01), Brannstrom et al.
patent: 4741290 (1988-05-01), Krieger et al.
patent: 4834947 (1989-05-01), Cook et al.
patent: 5039395 (1991-08-01), Martin et al.
Kim Christopher Y.
Kummert Lynn M.
Procedes Petroliers et Petrochimiques
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