RU2537440C1 - Furnace unit - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to a furnace unit including a housing, unions for raw material input and output, two separate radiation chambers; each chamber is equipped with an individual radiant coil and burners, the common convection chamber divided by a partition into two sections with a convective coil placed in each section. At that each section is interconnected by separate exhaust ducts; on the top through blocking elements with the common gas duct and at the bottom with two individual radiation chambers. It is expedient to make the blocking elements as a sliding shutter.

EFFECT: more effective use of furnace gas heat for heating of the convection coil placed in each section of the convection chamber during cleanup of coke deposits from one of radiant coils a higher efficiency factor is attained, significant simplification in start-up and shutdown operations.

5 cl, 3 dwg

Description

The invention relates to the field of oil refining and petrochemicals, in particular to tubular furnaces for heating petroleum feeds.

Known furnace unit, including a chimney and a body with convection and radiation chambers, which are convective and radiant coils and burners (JSC "VNIINEFTEMASH" catalog "Tube furnaces", Moscow 2007, p.8).

A disadvantage of the known furnace is that when coking the radiant coil, it is necessary to stop the furnace to clean the latter from coke deposits.

This drawback is eliminated in the furnace unit adopted for the prototype, including a chimney and a casing with two separate radiant chambers with radiant coils and burners and a common convection chamber with a convective coil. In such an aggregate, when cleaning the radiant coil from coke deposits, the radiant chamber to be cleaned is turned off, while the other radiant chamber is in the operating mode (Yagudin MN, “Thermal and aerodynamic calculation of tube furnaces”, Ufa, Izhevsk State Unitary Enterprise INKhP RB ”, 2008, p. 99).

A disadvantage of the known furnace unit is a violation of the heat transfer process in the common convection chamber when one of the radiation chambers is turned off, namely, insufficient thermal energy to heat the product in a convective coil located in the common convection chamber, which reduces the efficiency of the furnace unit. In addition, the use of a common convection chamber and two separate radiation chambers makes it difficult to stop and start one of the latter when coking a radiant coil.

The objective of the invention is the operation of the furnace unit without disrupting the heat transfer process and the simplification of operations to stop and start when switching to half load.

This problem is solved by the fact that in the furnace unit, including the housing, raw material inlet and outlet fittings, two separate radiation chambers, each of which is equipped with a separate radiant coil and burners, a common convection chamber, chimneys and a common gas duct, according to the invention, the convection chamber is divided by a partition into two sections, in each of which a convective coil is placed, each section communicated with separate chimneys, at the top through locking elements with a common gas duct, and at the bottom with two separate radiation chambers ui.

It is advisable to perform the locking elements in the form of a slide gate valve.

It is advisable to place in the convection chamber two fittings for the input of raw materials, one for each section.

It is advisable to provide each section of the convection chamber with two chimneys.

It is advisable to inform each section of convection with the corresponding radiation chamber by three chimneys.

Figure 1 shows the main view of the furnace unit in section, figure 2 is a side view and figure 3 is a spatial image.

The furnace unit consists of a housing 1, two radiation chambers 2, 3 with tubes 4, 5 of radiant coils and burners 6, 7, a convection chamber 8, divided by a partition 9 into two sections 10, 11, each of which is equipped with raw material inlets 12, 13 , pipes of convective coils 14, 15, connected respectively to pipes of radiant coils 4, 5, located in two separate radiation chambers 2, 3. Convection sections 10,11 are communicated from below with radiation chambers 2, 3, respectively, by chimneys 16a, 16b, 16c, 17a , 17b, 17c, and in the upper part are connected by chimneys 18a, 18b, 1 9a, 19b, equipped with slide gate valves 20a, 20b, 21a, 21b with a common gas duct 22. Radiation chambers 2, 3 are equipped with raw material outlet fittings 23, 24.

The furnace unit operates as follows.

Fuel is burned in burners 6, 7 located in radiation chambers 2 and 3, respectively. Most of the thermal energy released during the combustion of fuel in the form of radiation and partially convection is transmitted to radiant coils 4, 5 located respectively in radiation chambers 2,3. The rest of the energy in the form of hot flue gases through the chimneys 16a, 16b, 16c, 17a, 17b, 17c enters the convection chamber 8, divided by a partition 9 into two sections 10, 11 and, heating the convective coils 14.15, placed in the latter, through chimneys 18a, 18b, 19a, 19b, a common gas duct 22 and a chimney (not shown) are discharged into the atmosphere.

The heated product, such as tar, is sequentially heated first in the convective coils 14, 15 located in the convective sections 10, 11, and then in the radiant coils 4, 5 connected to them respectively, located in two separate radiation chambers 2, 3 and then through the fittings the output of raw materials 23, 24 leaves the furnace through a processing line (not shown).

When coking, for example, a radiant coil 4 located in the radiation chamber 2, the fuel supply to the burner 6 and the heated product are stopped in the convection coil 14 located in the section of the convection chamber 10, closing the gate valve 20 (a, b) placed in the chimney 18 (a, b). Then, the radiant coil 4 is cleaned, for example, mechanically from coke deposits. The furnace unit does not stop its work, the process of heating oil is carried out in the convective coil 15 of the convection section 11 and the radiant coil 5 of the radiation chamber 3.

The present invention allows more efficient use of flue gas heat for heating convective coils located in separate sections of the convection chamber. During operation of the furnace unit during cleaning of coke deposits of one of the radiant coils, a higher efficiency is achieved, and start-up and shutdown operations are greatly simplified. Due to the heating of raw materials without disrupting the heat transfer process, the efficiency of the furnace unit is increased.

Claims (5)

1. Furnace unit, comprising a housing, raw material input and output fittings, two separate radiation chambers, each of which is equipped with a separate radiant coil, burners, a common convection chamber, chimneys and a common gas duct, in which the convection chamber is divided by a partition into two sections, in each of which a convective coil is placed, with each section communicating with separate chimneys, at the top through locking elements with a common gas duct, and at the bottom with two separate radiation chambers. 2. The furnace unit according to claim 1, characterized in that the locking element is made in the form of a slide gate valve. 3. The furnace unit according to claim 1, characterized in that in the convection chamber there are two fittings for the input of raw materials, one for each section. 4. The furnace unit according to claim 1, characterized in that the convection chamber is equipped with four chimneys, two for each section. 5. The furnace unit according to claim 1, characterized in that each convection section is in communication with the corresponding radiation chamber by three chimneys.

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