CN219861030U - Oil return system before rifle and glass melting furnace - Google Patents

Abstract

The utility model discloses a gun front oil return system and a glass melting furnace, wherein the gun front oil return system comprises a gun front oil return main pipe and a plurality of oil supply channels which are arranged at intervals, each oil supply channel comprises an oil inlet pipe, a purge valve, an oil return branch pipe and an oil outlet pipe, and a switch is arranged on the oil return branch pipe. In the glass manufacturing process, when the combustion system is switched to the air supply system, the oil inlet pipe and the oil return branch pipe are communicated through the purging valve, the switch is opened, and then heavy oil in the oil inlet pipe is conveyed into the front oil return main pipe of the gun through the oil return branch pipe.

Description

Oil return system before rifle and glass melting furnace

Technical Field

The utility model relates to the technical field of oil supply systems of glass melting furnaces, in particular to a gun front oil return system and a glass melting furnace.

Background

Glass melters refer to the thermal equipment used to melt glass batch materials during the glass manufacturing process. At present, the fuel used for glass production mainly uses natural gas and heavy oil, and in order to relieve energy shortage and reduce glass manufacturing cost, two sets of combustion systems of an air supply system and an oil supply system are usually designed to be sequentially switched so as to realize heating of a glass melting furnace. With the increase of the switching frequency of the two sets of combustion systems, after the two sets of combustion systems are switched into the gas supply system, the residual oil in the oil pipe can not flow for a long time due to the characteristics of large molecular weight and high viscosity, and the problem of blocking the oil pipe to influence the glass production quality exists.

Among the prior art, oil feeding system still includes the passageway of blowing, and the passageway of blowing includes steam chest and sweeps the pipe, and steam chest and oil pipe pass through the pipe intercommunication of blowing. When the air supply system is switched into, steam in the steam box is conveyed into the oil pipe through the purging pipe, so that residual oil in the oil pipe is purged, and the residual oil in the oil pipe is blown back into the oil tank. But the whole purging and switching process is complicated, the workload of operators is increased, and meanwhile, certain potential safety hazards exist in the purging process, so that the problem of low glass production efficiency is solved.

Therefore, it is necessary to provide a new pre-gun oil return system and a glass melting furnace to solve the above technical problems.

Disclosure of Invention

The utility model mainly aims to provide a gun front oil return system and a glass melting furnace, and aims to solve the problems that the workload of operators is increased, potential safety hazards exist and the production efficiency is low in a purging channel of the existing oil supply system.

In order to achieve the above purpose, the gun front oil return system provided by the utility model comprises a gun front oil return main pipe and a plurality of oil supply channels arranged at intervals, wherein each oil supply channel comprises an oil inlet pipe, a purge valve, an oil return branch pipe and an oil outlet pipe, the input end of the oil inlet pipe and one end of the gun front oil return main pipe are communicated with an opening of an oil tank, the output end of the oil return branch pipe is communicated with the gun front oil return main pipe, a switch is arranged on the oil return branch pipe, and the output end of the oil inlet pipe is communicated with the oil return branch pipe and is positioned between the purge valve and the switch; the purging valve is communicated with the flame spraying gun through the oil outlet pipe, and when the switch is opened, the oil return branch pipe is communicated with the front oil return main pipe of the gun so as to convey heavy oil back into the oil tank through the front oil return main pipe of the gun.

Optionally, each oil supply channel further includes a three-way pipe fitting, the three-way pipe fitting is located between the purge valve and the switch, an oil inlet and two oil outlets which are oppositely arranged are formed in the three-way pipe fitting, the oil inlet is communicated with the output end of the oil inlet pipe, one oil outlet is communicated with the purge valve, and the other oil outlet is communicated with the oil return branch pipe.

Optionally, the switch is a ball valve, and the ball valve is used for switching on or switching off the oil return branch pipe and the oil return main pipe in front of the gun.

Optionally, a check valve is further arranged on the oil return branch pipe, and the check valve is located between the purge valve and the ball valve.

Optionally, the oil return system before the rifle still includes two flange ball valves and is located two mass flowmeter between the flange ball valve, mass flowmeter and two the flange ball valve all set up in before the rifle oil return is responsible for on, mass flowmeter is used for detecting the oil return in the oil return is responsible for before the rifle.

Optionally, the oil return system before the rifle still includes the steam tracing pipe, the steam tracing pipe with the other end intercommunication of the oil return main pipe before the rifle, be provided with the trap on the steam tracing pipe, the trap is used for discharging the comdenstion water in the steam tracing pipe.

Optionally, a heat preservation pipe is arranged on the periphery of the oil return main pipe in front of the gun.

In addition, the utility model also provides a glass melting furnace, which comprises a melting furnace body, an oil tank, a flame gun, a small furnace and the gun front oil return system, wherein the small furnaces are arranged in pairs, any pair of two small furnaces are symmetrically arranged on two sides of the melting furnace body, the number of the small furnaces is consistent with the number of the gun front oil return systems and are arranged in a one-to-one correspondence manner, one end of the gun front oil return system is connected with the oil tank, and the other end of the gun front oil return system is communicated with the flame gun.

Optionally, the glass melting furnace further comprises a conveying main pipe, the output ends of the two gun front oil return systems corresponding to any pair of the small furnaces are communicated with the conveying main pipe, and the output end of the conveying main pipe is communicated with the oil tank.

Optionally, the glass melting furnace further comprises an air supply system, the air supply system comprises an air inlet pipe and an air outlet pipe, two ends of the air inlet pipe are respectively communicated with the natural gas tank and the purging valve, and the purging valve is communicated with the flame gun through the air outlet pipe.

According to the technical scheme, the gun front oil return system comprises a gun front oil return main pipe and a plurality of oil supply channels which are arranged at intervals, each oil supply channel comprises an oil inlet pipe, a purge valve, an oil return branch pipe and an oil outlet pipe, the input end of the oil inlet pipe and one end of the gun front oil return main pipe are communicated with an opening of an oil tank, the output end of the oil return branch pipe is communicated with the gun front oil return main pipe, a switch is arranged on the oil return branch pipe, and the output end of the oil inlet pipe is communicated with the oil return branch pipe and is positioned between the purge valve and the switch; the purging valve is communicated with the flame gun through the oil outlet pipe, and when the switch is opened, the oil return branch pipe is communicated with the main oil return pipe in front of the gun so as to convey heavy oil into the oil return tank through the main oil return pipe in front of the gun. In the glass manufacturing process, when the combustion system is switched to the oil supply system, the oil inlet pipe is communicated with the oil outlet pipe through the purge valve, the input end of the oil inlet pipe is communicated with the opening of the oil tank, the oil tank conveys heavy oil into the oil inlet pipe through the oil pump, and the heavy oil is conveyed to the flame gun through the oil outlet pipe, so that the glass melting furnace is heated; when switching combustion system to gas supply system, advance oil pipe and oil return branch pipe and pass through the purge valve intercommunication, through opening the switch, and then advance the intraductal heavy oil of oil pipe and pass through the oil return branch pipe and carry to the rifle front oil return main pipe in, heavy oil passes through the rifle front oil return main pipe and carries back the oil tank again in, so that heavy oil is in circulation state all the time in advance oil pipe, oil return branch pipe and rifle front oil return main pipe, avoid remaining oil to pile up in the pipeline in order to block up the pipeline, no longer need use steam to sweep in the pipeline, the work burden of operating personnel has been alleviateed, the security of oil supply system has been improved, production cost has been reduced, and then glass's production efficiency has been improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a glass melting furnace according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of an oil supply channel according to an embodiment of the present utility model;

fig. 3 is a partial enlarged view of a portion a in fig. 1 according to an embodiment of the present utility model.

Reference numerals illustrate:

the achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present utility model are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present utility model, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical solutions of the embodiments of the present utility model may be combined with each other, but it is necessary to be based on the fact that those skilled in the art can implement the technical solutions, and when the technical solutions are contradictory or cannot be implemented, the combination of the technical solutions should be considered as not existing, and not falling within the scope of protection claimed by the present utility model.

The utility model provides a gun front oil return system and a glass melting furnace, and aims to solve the problems that the workload of operators is increased, potential safety hazards exist and the production efficiency is low in a purging channel of an existing oil supply system.

As shown in fig. 1 and 2, in an embodiment of the present utility model, the pre-gun oil return system 30 includes a pre-gun oil return main pipe 31 and a plurality of oil supply channels 32 arranged at intervals, each oil supply channel 32 includes an oil inlet pipe 321, a purge valve 322, an oil return branch pipe 323 and an oil outlet pipe 324, an input end of the oil inlet pipe 321 and one end of the pre-gun oil return main pipe 31 are both communicated with an opening of the oil tank 10, an output end of the oil return branch pipe 323 is communicated with the pre-gun oil return main pipe 31, a switch is arranged on the oil return branch pipe 323, and an output end of the oil inlet pipe 321 is communicated with the oil return branch pipe 323 and is located between the purge valve 322 and the switch; the purge valve 322 communicates with the torch 20 through the oil outlet pipe 324, and when the purge valve 322 is closed and the switch is opened, the oil return branch pipe 323 communicates with the pre-gun oil return main pipe 31 to convey heavy oil into the oil tank 10 through the pre-gun oil return main pipe 31.

In the above embodiment, in the glass manufacturing process, when the combustion system is switched to the oil supply system, the oil inlet pipe 321 and the oil outlet pipe 324 are communicated through the purge valve 322, and the input end of the oil inlet pipe 321 is communicated with the opening of the oil tank 10, the oil tank 10 conveys the heavy oil into the oil inlet pipe 321 through the oil pump, and then conveys the heavy oil to the flame gun 20 through the oil outlet pipe 324, so as to heat the glass melting furnace 100; when the combustion system is switched to the gas supply system, the oil inlet pipe 321 and the oil return branch pipe 323 are communicated through the purge valve 322, the switch is turned on, so that heavy oil in the oil inlet pipe 321 is conveyed into the gun front oil return main pipe 31 through the oil return branch pipe 323, the heavy oil is conveyed back into the oil tank 10 again through the gun front oil return main pipe 31, so that the heavy oil is always in a circulating state in the oil inlet pipe 321, the oil return branch pipe 323 and the gun front oil return main pipe 31, residual oil is prevented from accumulating in a pipeline to block the pipeline, steam is not required to be used for purging the pipeline, the work load of operators is reduced, the safety of the oil supply system is improved, the production cost is reduced, and the production efficiency of glass is further improved.

In the actual use process, the purge valve 322 is a pneumatic control purge valve 322, the pneumatic control purge valve 322 is composed of a pneumatic control piston and a sliding plate block, and the sliding plate block is driven to slide left and right by driving the piston to further realize the alternate connection or disconnection of the oil supply system and the gun front oil return system 30 so as to realize the functions of heating the glass melting furnace 100 and purging the heavy oil in the oil inlet pipe 321. When the combustion system is switched to the oil supply system, one end of the flame gun 20 is also communicated with an atomization gas pipeline, and the atomization gas is conveyed to the flame gun 20 through the atomization gas pipeline, so that the heavy oil is converted from a liquid state to atomized combustion, and the heavy oil can be fully combusted; when the combustion system is switched to the gas supply system, one end of the purge valve 322 is also communicated with a purge gas channel, and by setting a purge gas channel, residual heavy oil in the oil outlet pipe 324 can be blown into the glass melting furnace 100 through the purge gas in the purge gas channel by the flame gun 20, so that the heavy oil in the oil outlet pipe 324 is prevented from blocking the pipeline, and the muzzle of the flame gun 20 is effectively prevented from coking.

Wherein, each oil supply channel 32 also includes a three-way pipe fitting 325, the three-way pipe fitting 325 is located between the purge valve 322 and the switch, the three-way pipe fitting 325 is provided with an oil inlet and two opposite oil outlets, the oil inlet is communicated with the output end of the oil inlet pipe 321, one of the oil outlets is communicated with the purge valve 322, and the other oil outlet is communicated with the oil return branch pipe 323. Specifically, when the combustion system is switched to the oil supply system, an oil outlet communicated with the purge valve 322 is opened, and an oil outlet communicated with the oil return branch pipe 323 is closed, so that the oil inlet pipe 321 is communicated with the purge valve 322 through the three-way pipe fitting 325, heavy oil in the oil inlet pipe 321 is conveyed to the flame gun 20 through the oil outlet pipe 324, and the glass melting furnace 100 is heated; when the combustion system is switched to the gas supply system, an oil outlet communicated with the purge valve 322 is closed, an oil outlet communicated with the oil return branch pipe 323 is opened, and therefore the oil inlet pipe 321 is communicated with the oil return branch pipe 323 through the three-way pipe fitting 325, and heavy oil in the oil inlet pipe 321 is conveyed into the gun front oil return main pipe 31 through the oil return branch pipe 323 by opening a switch on the oil return branch pipe 323, and the heavy oil is conveyed into the oil return tank 10 again through the gun front oil return main pipe 31. The tee pipe 325 has the function of conduction, the tee pipe 325 has smaller flow resistance, and has the advantages of wider application range, simple structure and convenient installation.

In one embodiment, the switch is a ball valve 3231, and the ball valve 3231 is used to turn on or off the return manifold 323 and the pre-gun return main 31. Specifically, the ball valve 3231 is composed of a ball and a valve stem, the ball is driven by the valve stem and rotates around the axis of the valve stem to open or close the valve, and the ball valve 3231 can be tightly closed only by an operation of rotating by 90 ° and a small rotation moment. The ball valve 3231 has the advantages of convenient operation and rapid opening and closing, only needs to rotate 90 degrees from full opening to full closing, is convenient for remote control, has the advantages of convenient maintenance and easy replacement because of simpler structure of the ball valve 3231, and can ensure the balance of the heavy oil flow in each oil return branch 323 by adjusting the opening size of the corresponding ball valve 3231 when the heavy oil flow in any oil return branch 323 is large.

Based on the above embodiment, the oil return branch pipe 323 is further provided with a check valve 3232, and the check valve 3232 is located between the purge valve 322 and the ball valve 3231. The check valve 3232 is a valve in which the opening and closing member is a circular valve flap and acts by its own weight and pressure of the medium to block the reverse flow of the medium. By arranging the check valve 3232 on the oil return branch pipe 323, when the oil inlet pipe 321 and the oil return branch pipe 323 are communicated, the heavy oil can be ensured to always flow along the direction of the oil return main pipe 31 in front of the gun, the heavy oil is prevented from flowing in the opposite direction, and when the heavy oil flows reversely, the check valve 3232 is closed, so that the heavy oil is prevented from flowing reversely, and the check valve 3232 has good corrosion resistance and wear resistance.

Referring to fig. 3 in combination, the pre-gun oil return system 30 further includes two flange ball valves 311 and a mass flowmeter 312 located between the two flange ball valves 311, where the mass flowmeter 312 and the two flange ball valves 311 are disposed on the pre-gun oil return main pipe 31. The oil return amount in the front oil return main pipe 31 is detected through the mass flowmeter 312, so that an operator can adjust the flow amount of heavy oil in the front oil return main pipe 31 in time according to the oil return amount, the stability of the pressure in the front oil return main pipe 31 is ensured, and the safety and reliability of the front oil return system 30 are further improved; by arranging the flange ball valves 311 on both sides of the mass flowmeter 312, when the mass flowmeter 312 needs to be maintained and overhauled or replaced, the two flange ball valves 311 are closed, so that heavy oil does not exist in the gun front oil return main pipe 31 between the two flange ball valves 311, and the safety in the process of overhauling or replacing the mass flowmeter 312 is improved.

In addition, the gun front oil return system 30 further comprises a steam tracing pipe 33, the steam tracing pipe 33 is communicated with the other end of the gun front oil return main pipe 31, a drain valve 331 is arranged on the steam tracing pipe 33, and the drain valve 331 is used for discharging condensed water in the steam tracing pipe 33. Because the channel of the front oil return main pipe 31 is longer, the temperature of the heavy oil in the flowing process can be gradually reduced, so that the viscosity of the heavy oil can be increased, the mobility of the heavy oil can be influenced to block the front oil return main pipe 31, the other end of the front oil return main pipe 31 is communicated with the steam tracing pipe 33, the steam in the steam tracing pipe 33 is conveyed into the front oil return main pipe 31, the temperature in the front oil return main pipe 31 is further improved, and the mobility of the heavy oil in the front oil return main pipe 31 is ensured, so that the heavy oil is always in a circulating state in the oil inlet pipe 321, the oil return branch pipe 323 and the front oil return main pipe 31; meanwhile, after the steam is used, condensed water is easily formed in the front oil return main pipe 31 by liquefaction, the drain valve 331 plays a role in blocking steam and draining water, and the steam tracing pipe 33 can uniformly heat the front oil return main pipe 31.

Specifically, a heat preservation pipe is arranged on the periphery of the front oil return main pipe 31, and a heat preservation pipe is also arranged at the communication part of the front oil return main pipe 31 and the steam tracing pipe 33, so that the temperature in the front oil return main pipe 31 is further ensured, and the situation that the front oil return main pipe 31 is blocked due to poor flowability of heavy oil in the front oil return main pipe 31 is avoided. In the preferred embodiment, the insulating tube is made of glass wool, the glass wool is a cotton-shaped material formed by fibrillation of molten glass, and the glass wool has lower heat conductivity due to uniform fiber distribution and more slender fibers, so that the excellent insulating performance of the insulating tube is ensured, and the long-term insulating effect of the insulating tube is ensured; meanwhile, the glass wool also has higher strength, strong corrosion resistance, better stretching resistance and longer service life.

In addition, the utility model also provides a glass melting furnace 100, the glass melting furnace 100 comprises a melting furnace body, an oil tank 10, a flame gun 20, a plurality of small furnaces and the gun front oil return system 30, wherein the small furnaces are arranged in pairs, any pair of two small furnaces are symmetrically arranged on two sides of the melting furnace body, the number of the small furnaces is consistent with the number of the gun front oil return systems 30 and is arranged in a one-to-one correspondence manner, one end of the gun front oil return system 30 is connected with the oil tank 10, and the other end of the gun front oil return system 30 is communicated with the flame gun 20. The gun front oil return systems 30 are arranged on the two sides of the melting furnace body, so that when the combustion system is switched to the oil supply system, the flame guns 20 on the two sides of the melting furnace body can heat the interior of the melting furnace body at the same time, the melting speed of glass batch is increased, the heat utilization rate is improved, and the production yield and quality of glass are further improved; when the combustion system is switched to the gas supply system, heavy oil on two sides of the melting furnace body can be conveyed back into the oil tank 10 again through the front oil return main pipe 31, so that the residual oil is prevented from blocking all pipelines, steam is not required to be used for purging the pipelines, the work load of operators is lightened, the safety of the oil supply system is improved, the production cost is reduced, and the production efficiency of glass is further improved.

In the preferred embodiment, the number of the small furnaces is 18 according to the size of the melting furnace body, the 18 small furnaces are symmetrically arranged on two sides of the melting furnace body, and two small furnaces on each side are connected with one regenerator, so that the number of partition walls between the regenerators is reduced, the heat exchange area of the checker bricks is increased, the heat efficiency is improved, and the effects of saving energy and reducing consumption are achieved.

Since the glass melting furnace 100 includes the pre-gun oil return system 30 described above, the glass melting furnace 100 has all the advantages of the pre-gun oil return system 30 described above, and further description is omitted.

The glass melting furnace 100 further comprises a conveying main pipe, wherein the output ends of the two gun front oil return systems 30 corresponding to any pair of two small furnaces are communicated with the conveying main pipe, and the output end of the conveying main pipe is communicated with the oil tank 10. Specifically, the number of the mass flowmeters 312 is plural, the number of the mass flowmeters 312 is consistent with the number of the conveying main pipes and is set in one-to-one correspondence, and the mass flowmeters 312 are set on the corresponding conveying main pipes to detect the oil return amount in any pair of two gun front oil return main pipes 31, so that the corresponding small furnace heavy oil return flow is regulated to ensure the uniformity of the oil return amount of the gun front oil return system 30 corresponding to each small furnace.

In addition, the glass melting furnace 100 further comprises an air supply system, the air supply system comprises an air inlet pipe and an air outlet pipe, two ends of the air inlet pipe are respectively communicated with the natural gas tank and the purge valve 322, and the purge valve 322 is communicated with the flame gun 20 through the air outlet pipe. When the combustion system is switched to the gas supply system, natural gas in the natural gas tank is conveyed into the gas outlet pipe through the gas inlet pipe and is conveyed to the flame gun 20 through the gas outlet pipe so as to heat the melting furnace body. The quantity of the air supply systems is multiple, and the quantity of the air supply systems is consistent with the quantity of the small furnaces and is set in one-to-one correspondence, so that the sufficiency of the air supply systems for heating and melting glass batch materials in the melting furnace body is guaranteed, and the stability of natural gas combustion is guaranteed.

In the in-service use, gas supply system still includes gas regulating valve and flowmeter, and gas regulating valve and flowmeter all set up on the outlet duct, through the flowmeter with the gas outlet volume of detecting natural gas tank to the conveying of melting furnace body, gas regulating valve is used for adjusting the size of the gas outlet volume of natural gas to guarantee the homogeneity that gas supply system that each little stove corresponds carries out the gas supply to the melting furnace body, and then improve glass's production quality.

The foregoing description is only of the preferred embodiments of the present utility model and is not intended to limit the scope of the utility model, and all equivalent structural changes made by the description of the present utility model and the accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the utility model.

Claims (10)

1. The oil return system before the gun is characterized by comprising a main oil return pipe before the gun and a plurality of oil supply channels arranged at intervals, wherein each oil supply channel comprises an oil inlet pipe, a purge valve, an oil return branch pipe and an oil outlet pipe, the input end of the oil inlet pipe and one end of the main oil return pipe before the gun are communicated with an opening of an oil tank, the output end of the oil return branch pipe is communicated with the main oil return pipe before the gun, a switch is arranged on the oil return branch pipe, and the output end of the oil inlet pipe is communicated with the oil return branch pipe and is positioned between the purge valve and the switch; the purging valve is communicated with the flame spraying gun through the oil outlet pipe, and when the switch is opened, the oil return branch pipe is communicated with the front oil return main pipe of the gun so as to convey heavy oil back into the oil tank through the front oil return main pipe of the gun.

2. The pre-gun oil return system of claim 1 wherein each of said oil supply passages further comprises a three-way tube member positioned between said purge valve and said switch, said three-way tube member having an oil inlet opening and two oppositely disposed oil outlets, said oil inlet opening being in communication with an output of said oil inlet tube, one of said oil outlets being in communication with said purge valve and the other of said oil outlets being in communication with said oil return manifold.

3. The pre-gun oil return system of claim 1 wherein said switch is a ball valve for switching said oil return manifold and said pre-gun oil return main on and off.

4. The pre-gun oil return system of claim 3 wherein said oil return manifold is further provided with a check valve, said check valve being positioned between said purge valve and said ball valve.

5. The pre-gun oil return system of claim 1 further comprising two flange ball valves and a mass flow meter positioned between the two flange ball valves, the mass flow meter and the two flange ball valves both being disposed on the pre-gun oil return main pipe, the mass flow meter being configured to detect an amount of oil return in the pre-gun oil return main pipe.

6. The pre-gun oil return system of any one of claims 1 to 5 further comprising a steam tracing pipe, wherein the steam tracing pipe is communicated with the other end of the pre-gun oil return main pipe, a drain valve is arranged on the steam tracing pipe, and the drain valve is used for draining condensed water in the steam tracing pipe.

7. The pre-gun oil return system of any one of claims 1 to 5 wherein a heat preservation tube is provided around the perimeter of the pre-gun oil return main tube.

8. The glass melting furnace is characterized by comprising a melting furnace body, an oil tank, a flame gun, a small furnace and a plurality of gun front oil return systems according to any one of claims 1 to 7, wherein the small furnaces are arranged in pairs, any pair of the small furnaces are symmetrically arranged on two sides of the melting furnace body, the small furnaces are arranged in a one-to-one correspondence mode with the gun front oil return systems, one end of each gun front oil return system is connected with the oil tank, and the other end of each gun front oil return system is communicated with the flame gun.

9. The glass melting furnace of claim 8, further comprising a main conveying pipe, wherein the output ends of the two pre-gun oil return systems corresponding to any pair of two of the small furnaces are communicated with the main conveying pipe, and wherein the output ends of the main conveying pipe are communicated with the oil tank.

10. The glass melting furnace of claim 9, further comprising a gas supply system comprising a gas inlet pipe and a gas outlet pipe, wherein both ends of the gas inlet pipe are respectively in communication with the natural gas tank and the purge valve, and wherein the purge valve is in communication with the flame gun through the gas outlet pipe.