Electric radiation convection internal circulation cylinder heating furnace

Abstract

An electric radiation convection internal circulation cylinder heating furnace comprises a cylinder furnace steel structure, the cylinder furnace steel structure supports a whole shell, the cylinder furnace steel structure is welded to a cylinder furnace wall plate, the inner side of the wall plate is a heat insulation lining, furnace tubes are distributed in multiple layers along the circumference, and electric heating tubes are arranged between the furnace tubes in each layer. The whole electric radiation cylinder furnace is totally closed and is filled with carbon dioxide, so that the electric heating tube is protected from being oxidized. A variable-frequency fan is arranged at the top of the furnace, blades of the variable-frequency fan extend into the furnace body, and the blades rotate to drive carbon dioxide inert gas in the furnace body to circularly flow to perform convective heat exchange with the furnace tube. Materials enter the furnace tube from the inlet and flow in the furnace tube to absorb heat. The electric heating pipes are evenly distributed between the two layers of coil pipes, the electric heating pipes emit heat after being powered on, and heat is transmitted to the furnace pipe in a radiant heat mode and transmitted to a medium from the furnace pipe. The gas heating furnace is clean, environment-friendly, high in safety, high in intelligence, convenient to adjust and rapid to start, and the heat efficiency can reach about 98% and is far higher than that of a traditional gas heating furnace.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of petroleum chemical heating furnace, relates to a kind of electric radiation convection internal circulation cylindrical heating furnace for the heating of various process media of petroleum chemical industry. BACKGROUND

[0002] The existing process heating furnace in the field of petroleum chemical industry mostly uses gas heating furnace, which has problems of high fuel consumption, large carbon emission and emission of pollutants such as nitrogen oxides. The gas heating furnace needs to be matched with a combustion control system, and the equipment occupies a large area, and there is a safety hazard of gas leakage.

[0003] The electric radiation convection internal circulation cylindrical heating furnace of the utility model can completely replace the fuel or gas process heating furnace in the petrochemical industry, and is suitable for heating various process media, i.e. it can be used for new construction or the modification of existing gas heating furnaces. INVENTION CONTENTS

[0004] The utility model provides electric radiation convection internal circulation cylindrical heating furnace, relative to pure radiation furnace, increase convective heat transfer, so that furnace tube receives radiation and convective heat transfer at the same time, and higher surface heat intensity can be obtained, and the use of materials and the area occupied are both less under the same load.

[0005] The technical scheme of the utility model is as follows:

[0006] An electric radiation convection internal circulation cylindrical heating furnace comprises a cylindrical furnace steel structure, which supports the entire shell, and is welded with cylindrical furnace wall plates, the inner side of the wall plates is a heat insulation lining, and electric heating pipes are arranged between each layer of furnace pipes along the circumference. The entire electric radiation cylindrical furnace is fully enclosed, filled with carbon dioxide inside, and the electric heating pipes are protected from oxidation. A frequency conversion fan is arranged on the top of the furnace, the blades of the frequency conversion fan extend into the furnace body, and the rotation of the blades drives the circulation of the carbon dioxide inert gas in the furnace body, and the carbon dioxide inert gas exchanges heat with the furnace pipes by convection.

[0007] The inner core of the electric heating pipe is a heating resistance wire, the sleeve is made of high alloy steel or a suitable material selected according to the characteristics and use temperature of the heating medium, and magnesium oxide powder is filled between the resistance wire and the sleeve for insulation.

[0008] The explosion-proof junction box used in the electric radiation convection internal circulation cylindrical heating furnace can achieve a DIICT4 explosion-proof level according to the on-site use requirements, and is suitable for the characteristics of high explosion-proof requirements in the petrochemical industry. The protection level can reach IP65 or above, and can be suitable for outdoor installation.

[0009] The electric heating pipe is provided with a temperature measuring element, and an over-temperature interlocking protection system is arranged to stop heating when the temperature exceeds the set temperature. Temperature measuring elements are arranged at the medium inlet and outlet, and the power of the heating pipe is adjusted according to the temperature at the inlet and outlet.

[0010] Further features, the shell is protected by carbon dioxide or other inert protective gas.

[0011] Further features, the furnace tube arrangement adopts spiral coil, vertical coil and various forms.

[0012] Material from the inlet into the furnace tube, flow in the furnace tube to absorb heat. Electric heating tube is evenly distributed in the two layers of coil, after power heating tube heating, heating tube to the heat transfer to the medium in the form of radiant heat.

[0013] The existing cylinder gas heating furnace is modified into an electric radiation convection internal circulation cylinder heating furnace. The steel structure, furnace wall, furnace tube and furnace lining of the original gas heating furnace can be reused, and the shell is fully sealed. The fire door and manhole door are modified into sealed type. The utility model has the following advantages

[0014] (1) Clean and environmentally friendly: no combustion exhaust gas is produced, and no pollutants are produced.

[0015] (2) High safety: the equipment is provided with various safety protection devices, and the safety factor is high. There is no safety hazard such as gas leakage and explosion.

[0016] (3) High intelligence: easy to realize automatic control and remote operation, reduce manual intervention. Precise temperature control, more easily realize accurate temperature control, meet the process demand of higher temperature control requirement.

[0017] (4) Easy to adjust: the temperature can be adjusted by adjusting the power of the heating module, which can meet the needs of large changes in operation.

[0018] (5) Start quickly: it can quickly start and reach working temperature, without the complicated ignition and preheating process of gas heating furnace.

[0019] (6) Simple system: there is no complex component related to the combustion system, the maintenance cost is low and the maintenance work is relatively simple.

[0020] (7) The utility model has only one heat loss, and the thermal efficiency can reach about 98%. Much higher than the traditional gas heating furnace. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the vertical sectional view of the utility model;

[0022] Figure 2 is the horizontal sectional view of the utility model;

[0023] Figure 3 is a local enlarged view of the utility model.

[0024] In the figure: 1 explosion-proof terminal box; 2 electric heating tube; 3 medium inlet; 4 steel structure; 5 furnace wall plate; 6 heat insulation lining;

[0025] 7 furnace tube; 8 medium outlet; 9 flange cover; 10 flange; 11 sleeve; 12 temperature measuring element; 13 control inlet;

[0026] 14 power supply inlet; 15 variable frequency fan. DETAILED DESCRIPTION

[0027] The specific embodiments of the utility model will be further described below in combination with the technical solutions and the drawings.

[0028] The process medium enters the furnace tube from the medium inlet 3, enters the inside of the furnace body for heating, and the heated process medium flows out from the medium outlet 8. Temperature and pressure instruments are arranged at the medium inlet and outlet, the power of the electric heating tube is adjusted according to the temperature and pressure of the inlet and outlet, and an over-temperature and over-pressure alarm device is arranged.

[0029] The control inlet 13 and the power supply inlet 14 are respectively connected with the electric control system, power is supplied to the electric heating tube, and the signals of the temperature, pressure and other instruments are received. Electricity is connected through the explosion-proof terminal box 1, and the electric heating tube 2 generates heat after being electrified. The medium enters the furnace tube 7 through the inlet 3, the furnace tube 7 is in the furnace body, the medium flows in the furnace tube 7 to absorb heat, the heat comes from the radiant heat and the convection heat of the electric heating tube 2, and the heated medium flows out from the medium outlet 8. The heating furnace cavity is sealed, and is filled with inert protective gas carbon dioxide.

[0030] The electric radiation convection inner circulation cylindrical heating furnace shell is sequentially provided with a steel structure 4, a furnace wall plate 5 and a heat insulation lining 6 from outside to inside. The steel structure provides support for the whole cylindrical furnace, the outer part of the furnace wall plate is welded with the steel structure, the inner part of the furnace wall plate is connected with the heat insulation lining through heat preservation nails, and the heat insulation lining 6 reduces heat loss.

[0031] The electric heating tube enters the inside of the furnace body through the sleeve 11 on the furnace top, the upper part of the sleeve is a flange 10, and the flange 10 is connected with the flange cover 9 to realize the functions of support and sealing.

[0032] The variable frequency fan 15 is arranged on the furnace top, the blades of the variable frequency fan 15 extend into the furnace body, the rotation of the blades drives the circulation flow of the carbon dioxide inert gas in the furnace body, and the carbon dioxide inert gas performs convection heat exchange with the furnace tube 7.

Claims

1. An electrically radiating convection internally circulating cylindrical heating furnace characterized by, The cylindrical furnace steel structure supports the whole shell, and is welded with the cylindrical furnace wall plate, the inner side of the wall plate is a heat insulation lining, the furnace pipes are distributed in multiple layers along the circumference, and electric heating pipes are arranged between each layer of furnace pipes; the whole electric radiation cylindrical furnace is fully enclosed, is filled with carbon dioxide inside, and the electric heating pipes are protected from oxidation; a variable frequency fan is arranged on the top of the furnace, the blades of the variable frequency fan extend into the furnace body, and the rotation of the blades drives the circulation and flow of the carbon dioxide inert gas in the furnace body to conduct convective heat exchange with the furnace pipes.

2. An electrically heated cylindrical furnace of the type having internal circulation of electrically radiated convection currents as defined in claim 1, wherein, The inner core of the electric heating pipe is a heating resistance wire, the sleeve is made of high alloy steel or appropriate material selected according to the characteristics of the heating medium and the use temperature, and magnesium oxide powder is filled between the resistance wire and the sleeve for insulation.

3. An electrically heated cylindrical furnace of the type having internal circulation of electrically radiated convection currents as defined in claim 1, wherein: The explosion-proof junction box used in the electric radiation convection internal circulation cylindrical heating furnace can achieve the explosion-proof level of DIICT4 according to the use requirements on the spot; the protection level can achieve IP65 and above, and is suitable for outdoor installation.

4. An electrically heated cylindrical furnace of the type having internal circulation of electrically radiated convection currents as defined in claim 1, wherein, The electric heating pipe is provided with a temperature measuring element, and an over-temperature interlocking protection system is arranged to stop heating when the temperature exceeds the set temperature; temperature measuring elements are arranged at the medium inlet and outlet, and the heating pipe power is adjusted through the inlet and outlet temperature.

5. An electrically heated, radiation convection, internally circulating cylindrical furnace according to claim 1, wherein, The protective gas in the shell is carbon dioxide.

6. An electrically heated, radiation convection, internally circulating cylindrical furnace according to claim 1, wherein, The furnace pipe arrangement adopts spiral coil pipes or vertical coil pipes.

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