The heat exchanger of heat exchanger, formaldehyde oxidation reactor
Technical field
The utility model relates to a kind of heat exchanger, particularly the heat exchanger of heat exchanger, formaldehyde oxidation reactor.
Background technology
Formaldehyde oxidation reactor is the key equipment of Formaldehyde Production, and its quality will be directly connected to the quality of product quality, influences the raising of economic benefit.The major function of oxidator is that methanol oxidation generates formaldehyde gas, reclaims the reaction gas heat and cools off reaction gas.
At present, domestic formolite reaction device mainly contains two-period form and two kinds of structures of syllogic.The two-period form oxidation reactor is made up of upper and lower two parts, and top is conversion zone, and methyl alcohol, air, water vapour three-element mixed gas body oxidation reaction take place generate formaldehyde gas when entering by the catalyst layer of electric furnace igniting heating; The bottom is a cooling section, and the high temperature formaldehyde gas that reaction generates is sent in this water cooling that is cooled, and cooling water discharges under normal pressure, though reached cooling purpose, the technology waste heat is not utilized, and has wasted a large amount of heat energy, and has consumed a large amount of cooling waters.Up to the present, the two-period form formaldehyde oxidation reactor progressively is eliminated.
Syllogic oxidation of formaldehyde device is made up of three parts, and epimere is an oxidation panel, and the stage casing is the waste heat recovery section, and hypomere is the gas cooled section.The effect of epimere oxidation panel is identical with the two-period form oxidator; The effect of stage casing waste heat recovery section is the mode by heat exchange, utilizes the heat energy of high temperature formaldehyde gas to produce low-pressure steam; The effect of hypomere cooling section is that the formaldehyde gas that will come from the waste heat recovery section is cooled to below 100 degree.The syllogic oxidation reactor has made full use of the technology waste heat, and effect is remarkable aspect energy-conservation, water saving.But this reactor condition of work is worsened, waste heat recovery section tube sheet on high temperature side, the connecting portion of tube sheet and heat exchanger tube is in (temperature is up to the 550-650 degree) under the high temperature, should bear pressure, be subjected to the impact and the corrosion of high temperature, high-speed gas again, the tube-to-tube sheet connection junction is very easily damaged, austenitic stainless steel is higher than 525 when spending in serviceability temperature in addition, the intensity of material, plasticity and non-oxidizability significantly descend, cause breakage to repair, cause service life of equipment short, economic benefit can not get performance.
Fig. 6 has shown a kind of existing syllogic oxidation of formaldehyde device, comprising: convection tube 101; Housing 102; Heat exchanger tube 103; Steam (vapor) outlet 104; Upper perforated plate 105; Inner barrel 106; Catalyst layer 107; Quaternary gaseous mixture inlet 108; Deflection plate 109; Red copper bar 110; End socket 111; Oxidizing chamber 112; Take over 113; Vessel flange 114; Copper mesh 115; The hot water inlet 116; Take over 117; Lower perforated plate 118; Formaldehyde gas outlet 119.
Fig. 7 has shown the annexation of the upper perforated plate 105 among Fig. 6 with housing 102, and wherein, the upper perforated plate 105 of flat tube plate structure is by being welded to connect housing 102, because the existence of high temperature difference causes the stress cracking state easily.
In addition, from the 108 easy condensations of quaternary gaseous mixture that enter of quaternary gaseous mixture inlet, thereby influence activity of such catalysts.
Fig. 8 A has shown the structure of the heat exchanger tube 103 among Fig. 6, as can be seen from the figure, fills solid pure red copper bar 110 in the heat exchanger tube 103, and its cross section is shown in Fig. 8 B, and this pure red copper bar 110 is fixed on copper rod and supports on 120.This structure makes pure red copper bar 110 can contact with heat-exchange tube 104 inwalls at no time, so that stream of gaseous formaldehyde is logical, therefore reduced heat exchanger effectiveness, and solid red copper bar has also increased cost.
In addition, be provided with quaternary gaseous mixture 108 parts such as grade that enter the mouth owing to generate the oxidizing chamber 112 of formaldehyde gas, make that catalyst layer 107 must be away from top cover, therefore, when catalyst changeout more, must earlier end socket be shed, the operator enters by ladder and carries out mating formation of catalyst in the oxidizing chamber then, causes more very inconvenience of catalyst changeout.
Summary of the invention
The purpose of this utility model provides a kind of heat exchanger that can improve the formaldehyde oxidation reactor of heat exchanger effectiveness in the formaldehyde oxidation reactor.
Above-mentioned purpose of the present utility model is achieved in that a kind of heat exchanger of formaldehyde oxidation reactor, comprises the housing that is filled with the efficient heat transfer part in it, it is characterized in that described efficient heat transfer part comprises:
Plug; And
Strip silk ribbon on described plug spirally is fastened.
Wherein, the top and bottom of described housing connect upper perforated plate and the lower perforated plate in the described formaldehyde oxidation reactor respectively.
Wherein, the described outward flange that is fastened the strip silk ribbon expanded by heating on described plug contacts with the inwall of described heat exchanger shell.
And described strip silk ribbon is the flat-shaped silk ribbon.
Above-mentioned flat-shaped silk ribbon is to be formed by the copper wire braiding, good permeability, even contact with heat-exchange tube, also can breathe freely, therefore can design and produce the flat-shaped silk ribbon that can contact heat-exchange tube at the outward flange of expanded by heating, thereby can fast reaction heat be passed to tube wall, improve heat transfer efficiency, promptly improve heat exchanger effectiveness.
Wherein, described strip silk ribbon is the flat-shaped silk ribbon, and the material of described plug and flat-shaped silk ribbon is a red copper.
Another purpose of the present utility model provides a kind of heat exchanger that is suitable for improving the heat exchanger effectiveness of gas.
This purpose of the present utility model is achieved in that a kind of heat exchanger, comprises the housing that is filled with the efficient heat transfer part in it, it is characterized in that described efficient heat transfer part comprises:
Plug; And
Strip silk ribbon on described plug spirally is fastened.
Wherein, described heat exchanger is a heat-exchange tube.
Wherein, the outward flange of the described strip silk ribbon expanded by heating on described plug that is fastened contacts with described heat-exchange tube inwall.
And described strip silk ribbon is the flat-shaped silk ribbon.
Above-mentioned flat-shaped silk ribbon is to be formed by the copper wire braiding, good permeability, even contact with heat-exchange tube, also can breathe freely, therefore can design and produce the flat-shaped silk ribbon that behind expanded by heating, can contact heat-exchange tube, thereby can fast reaction heat be passed to tube wall, improve heat transfer efficiency, promptly improve heat exchanger effectiveness.In addition, described strip silk ribbon is the flat-shaped silk ribbon, and the material of described plug and flat-shaped silk ribbon is a red copper.
In addition, the suitable formaldehyde oxidation reactor of the utility model comprises:
Top cover;
The oxidator main cylinder that connects described top cover is provided with in it and is used for taking place the catalyst layer that oxidative dehydrogenation generates formaldehyde gas;
Connect described oxidator main cylinder to export the device of the formaldehyde gas that has generated;
It is characterized in that described top cover comprises:
Insulation jacket is made up of inner barrel that is tightly connected and outer cylinder body, forms heating interlayer between described outer cylinder body and inner barrel;
Enter the quaternary gaseous mixture inlet of top cover inside from outer cylinder body, the inner barrel of insulation jacket; And
Be used for the distribution that the quaternary gaseous mixture that enters from quaternary gaseous mixture inlet is evenly distributed on the described catalyst layer surface is bored, this distribution awl lower end is fixed on the inner barrel inwall.
Because the heating of above-mentioned insulation jacket has improved the temperature in the top cover, therefore can eliminate because of the condensation of quaternary gaseous mixture influence to catalyst.
The utility model is by on the insulation interlayer of described top cover the steam inlet being set and condensation-water drain is realized above-mentioned insulation jacket heating function, i.e. the described top cover of the Steam Heating of utilizing described steam inlet to provide.
In addition, described oxidator main cylinder also is provided with:
Be positioned at the steam (vapor) outlet of oxidator main cylinder upper end; And
Be positioned at the upper perforated plate under the described steam (vapor) outlet, described upper perforated plate upper end is fixed on the oxidator main cylinder.
Owing on the steam (vapor) outlet upper perforated plate, make that upper perforated plate can be under water fully, help overcoming cavitation erosion to upper perforated plate.
Wherein, described upper perforated plate is the inferior flat tube sheet with radian, and its two ends upwarp and form the upper end, and described upper end connects as one by welding and oxidator main cylinder inwall.
Because upper perforated plate is the inferior flat tube sheet with radian, makes upper perforated plate have sufficient elongate space, has overcome the stress cracking phenomenon that high temperature difference causes well, solved the stress corrosion problem that long-term puzzled technical staff does not have the oxidator waste heat boiler section of solution.
Described oxidator main cylinder also is provided with:
Heat-exchange tube, its upper end connects the lower end of described upper perforated plate; And
Be positioned under the described heat-exchange tube and fixedly connected with it lower perforated plate, its two ends are fixed on the oxidator main cylinder inwall.
Wherein, described top cover connects described oxidator main cylinder by flange.And described catalyst layer is positioned at the upper end of oxidator main cylinder.Like this, when catalyst changeout more,, lay down top cover as long as turn on the bolt of the flange that connects top cover and oxidator main cylinder, just can be easily catalyst changeout more.
Wherein, described oxidator main cylinder connects the skirt with the outlet of formaldehyde gas by flange seal.
Wherein, described oxidator main cylinder also is provided with:
Be positioned at the hot water inlet of oxidator main cylinder lower end, be used to supply with heat exchanger tube in the gas heat exchange of high temperature formaldehyde and produce the hot water of steam.
Wherein, below catalyst layer, be provided with the catalyst that links to each other with the oxidator main cylinder and support cylindrical shell;
In described catalyst supported cylindrical shell, copper mesh was placed directly on the upper perforated plate, and
Described catalyst layer is laid on the described copper mesh.
Wherein, the upper end fix in position of described plug is on the stainless steel wire on the upper perforated plate.This can improve gas speed, has shortened the time of staying of formaldehyde gas in the high-temperature region, thereby has reduced side reaction.
In sum, with respect to prior art, the utlity model has following technique effect:
Improve the heat transfer efficiency of heat-exchange tube, thereby improved the exchange efficiency of heat exchanger.
In addition, utilize the formaldehyde oxidation reactor of heat-exchange tube of the present utility model can reach following technique effect:
1, eliminated the influence of the condensation of quaternary gaseous mixture, improved the efficient that oxidative dehydrogenation generates formaldehyde gas takes place catalyst;
2, overcome the stress cracking phenomenon that high temperature difference causes well, solved the stress corrosion problem that long-term puzzled technical staff does not have the oxidator waste heat boiler section of solution;
3, make things convenient for the replacing of catalyst.
Below in conjunction with accompanying drawing the utility model is elaborated.
Description of drawings
Fig. 1 is the schematic diagram of formaldehyde oxidation reactor of the present utility model;
Fig. 2 A has shown the connection state of the upper perforated plate 5 among Fig. 1 with oxidator main cylinder 2;
Fig. 2 B is the sectional view of the upper perforated plate 5 among Fig. 1;
Fig. 3 has shown the annexation of top cover 22 and oxidator main cylinder 2 among Fig. 1;
Fig. 4 has shown the structure of the heat exchanger tube 3 among Fig. 1;
Fig. 5 A is the profile of the top cover 22 among Fig. 1;
Fig. 5 B is the profile of the A-A direction of Fig. 5 A;
Fig. 6 is the schematic diagram of the formaldehyde oxidation reactor of prior art;
Fig. 7 shown the upper perforated plate among Fig. 6 structure and with the connection status of housing; And
Fig. 8 A has shown the structure of the heat exchanger tube among Fig. 6;
Fig. 8 B is the sectional view of the red copper bar among Fig. 8 A.
Description of reference numerals: 1-skirt; 2-oxidator main cylinder; The 3-heat exchanger tube; The 4-steam (vapor) outlet; The 5-upper perforated plate; The 6-catalyst supports cylindrical shell; The 7-catalyst layer; 8-quaternary gaseous mixture inlet; The 9-steam inlet; The 10-awl that distributes; The 11-inner barrel; The 12-insulation jacket; The 13-condensation-water drain; The 14-flange; The 15-copper mesh; The 16-hot water inlet; The 17-flange; The 18-lower perforated plate; The outlet of 19-formaldehyde gas; 20-strip silk ribbon; The 21-plug; The 22-top cover; The 23-outer cylinder body; The 24-stainless steel wire.
The specific embodiment
At first referring to Fig. 4, heat exchanger of the present utility model (or heat-exchange tube) 3 comprises the housing that is filled with the efficient heat transfer part in it, it is characterized in that described efficient heat transfer part comprises:
Plug 21; And
Strip silk ribbon 20 on described plug 21 spirally is fastened.
The outward flange of described strip silk ribbon 20 expanded by heating on described plug 21 that are fastened (being the edge of close heat exchanger 3 housings among Fig. 4) contacts with the inwall of described heat exchanger shell.
Described strip silk ribbon 20 is flat-shaped silk ribbons.
Above-mentioned flat-shaped silk ribbon 20 is to be formed by the copper wire braiding, good permeability, even contact with heat-exchange tube, also can breathe freely, therefore can design and produce the flat-shaped silk ribbon 20 that behind expanded by heating, can contact heat-exchange tube, thereby can fast reaction heat be passed to tube wall, improve heat transfer efficiency, promptly improve heat exchanger effectiveness.
The upper end of above-mentioned housing connects the upper perforated plate 5 of formaldehyde oxidation reactor, and its lower end connects the lower perforated plate 18 (referring to Fig. 1) in the formaldehyde oxidation reactor.
Above-mentioned strip silk ribbon 20 is the flat-shaped silk ribbon; And the material of above-mentioned plug 21 and flat-shaped silk ribbon 20 is red copper.
Below in conjunction with description of drawings heat exchanger application of the present utility model in the situation of formaldehyde oxidation reactor.
Referring to Fig. 1, formaldehyde oxidation reactor of the present utility model comprises:
Top cover 22;
The oxidator main cylinder 2 that connects described top cover 22 is provided with in it and is used for taking place the catalyst layer 7 that oxidative dehydrogenation generates formaldehyde gas;
Connect described oxidator main cylinder 2 to export the device of the formaldehyde gas that has generated, in this case, this device is the skirt 1 that is provided with formaldehyde gas outlet 19;
It is characterized in that described top cover 22 comprises:
Insulation jacket 12 is made up of inner barrel 11 that is tightly connected and outer cylinder body 23, forms heating interlayer between described outer cylinder body 23 and inner barrel 23;
Enter the quaternary gaseous mixture inlet 8 of top cover 22 inside from outer cylinder body 23, the inner barrel 23 of insulation jacket 12; And
Be used for be evenly distributed on described catalyst layer 7 lip-deep distribution awls 10 from the quaternary gaseous mixture inlet 8 quaternary gaseous mixtures that enter, these distribution awl 10 lower ends are fixed on inner barrel 11 inwalls.
Because the above-mentioned insulation jacket 12 of heating can improve the temperature in the top cover 22, thereby eliminated, can improve catalyst layer 7 thus the efficient that oxidative dehydrogenations generate the formaldehyde gas takes place because of the condensation of quaternary gaseous mixture influence to catalyst.
The utility model is by on the insulation interlayer 12 of described top cover 22 steam inlet 9 being set and condensation-water drain 13 is realized above-mentioned insulation jacket 12 heating functions, the described top cover 22 of Steam Heating that promptly utilizes described steam inlet 9 to provide.
In addition, described oxidator main cylinder 2 also is provided with:
Be positioned at the steam (vapor) outlet 4 of oxidator main cylinder 2 upper ends; And
Be positioned at the upper perforated plate 5 under the described steam (vapor) outlet 4, described upper perforated plate 5 upper ends are fixed on oxidator main cylinder 2 inwalls.
Because steam (vapor) outlet 4 is positioned on the upper perforated plate 5, makes that upper perforated plate can be under water fully, helps overcoming the corrosion of air to upper perforated plate.
Referring to Fig. 2 A and Fig. 2 B, described upper perforated plate 5 is the inferior flat tube sheets (promptly not being dull and stereotyped completely) with radian, and its two ends upwarp and form the upper end, and described upper end connects as one by welding and oxidator master tube 2 body inwalls.
Because upper perforated plate 5 is the inferior flat tube sheets with radian, make upper perforated plate 5 have sufficient elongate space, overcome the stress cracking phenomenon that high temperature difference causes well, solved the stress corrosion problem that long-term puzzled technical staff does not have the oxidator waste heat boiler section of solution.
Described oxidator main cylinder 2 also is provided with:
Vertically be arranged on a plurality of heat-exchange tubes 3 in the oxidator main cylinder 2, the upper end of each heat-exchange tube 3 connects the lower end of described upper perforated plate 5; And
Be positioned under the described heat-exchange tube 3 and fixedly connected with it lower perforated plate, its two ends are fixed on oxidator main cylinder 2 inwalls.
Wherein, described top cover 22 connects described oxidator main cylinder 2 by flange 14.And described catalyst layer 7 is positioned at the upper end of oxidator main cylinder 2.Like this, when catalyst changeout more,, lay down top cover 22 as long as turn on the bolt (not shown) of the flange 14 that connects top cover 22 and oxidator main cylinder 2, just can be easily catalyst changeout more.
Described oxidator main cylinder 2 is tightly connected by flange 17 and has the skirt 1 of formaldehyde gas outlet 19.
Described oxidator main cylinder 2 also is provided with:
Be positioned at the hot water inlet 16 of oxidator main cylinder 2 lower ends, be used to supply with heat exchanger tube 3 in the gas heat exchange of high temperature formaldehyde and produce the hot water of steam.
Wherein, below catalyst layer 7, be provided with the catalyst that links to each other with oxidator main cylinder 2 and support cylindrical shell 6;
In supporting cylindrical shell 6, places by described catalyst copper mesh 15, and
Described catalyst layer 7 is laid on the described copper mesh 15.
As shown in Figure 4,3 are filled with the efficient heat transfer part in the heat-exchange tube, and this efficient heat transfer part comprises:
Plug 21; And
Flat-shaped silk ribbon 20 on described plug 21 spirally is fastened.
The outward flange of described flat-shaped silk ribbon 20 expanded by heating on described plug 21 that are fastened can contact with described heat-exchange tube 3 inner walls.
Because described flat-shaped silk ribbon 20 is to be formed by the copper wire braiding, good permeability, even contact with heat-exchange tube, also can breathe freely, therefore can design and produce the flat-shaped silk ribbon 20 that behind expanded by heating, can contact heat-exchange tube, thereby can fast reaction heat be passed to tube wall, improve heat transfer efficiency, promptly improve heat exchanger effectiveness.
Wherein, the upper end fix in position of described plug 21 is (this stainless steel wire 24 is supported by upper perforated plate 5) on the stainless steel wire on the upper perforated plate 5 24, and this can improve gas speed, has shortened the time of staying of formaldehyde gas in the high-temperature region, thereby has reduced side reaction.Wherein, the material of described plug 21 and flat-shaped silk ribbon 20 is a red copper.
Below in conjunction with accompanying drawing the structure of the present utility model and the course of work are described in detail.
As shown in Figure 1, the quaternary gaseous mixture enters oxidator from quaternary gaseous mixture inlet 8, passes catalyst layer generation oxidative dehydrogenation and generates formaldehyde gas, and formaldehyde enters absorption system by formaldehyde gas outlet 19 after heat exchange.
The inner barrel 11 of oxidator top cover passes through vessel flange 14 sealing and fixing together with oxidator main cylinder 2, the quaternary gaseous mixture enters in the oxidator by the quaternary gaseous mixture inlet of opening in inner barrel 11 upper ends 8, the top cover 22 of oxidator is set up insulation jacket 12, steam 9 enters from the steam inlet, condensed water flows out from condensation-water drain 13, has eliminated because of the influence to catalyst of the condensate liquid of quaternary gaseous mixture.
The awl 10 that distributes is set in the oxidator top cover 11, and the lower end of the awl 10 that distributes is welded on the wall of top cover inner barrel 11, and under awl 10 effects that distribute, it is even that gas becomes.This is because quaternary gas is when entering the oxidator top cover, plays the effect of a redistribution through the throttling action of the awl 10 that distributes, and the awl 10 that distributes is concentric circles with inner barrel 11 again so can play and make air-flow steadily be evenly distributed on the effect of catalyst surface.Avoided because of of the influence of air-flow rotary impact, reduced because even incomplete pure content of reaction and the acidity height of causing of catalyst out-of-flatness surface or became uneven, influenced unit consumption and product quality is defective catalyst coating.
Oxidator main cylinder 2 upper ends are catalyst layer 7, and catalyst supports cylindrical shell 6 and links to each other with oxidator main cylinder 2, and copper mesh 15 is placed on catalyst and supports in the cylindrical shell 6, is covered with catalyst layer 7 on the copper mesh 15.
The upper perforated plate 5 of catalyst layer below is inferior flat tube plate structure, make tube sheet have sufficient elongate space, overcome the stress cracking phenomenon that high temperature difference causes well, solved the stress corrosion problem that long-term puzzled technical staff does not have the oxidator waste heat boiler section of solution, the upper end of upper perforated plate 5 is fixed by welding on the oxidator main cylinder 2, and the lower end of upper perforated plate 5 links to each other with the upper end of heat exchanger tube 3 by welding.
Be filled with red copper efficient heat transfer part in the heat exchanger tube 3, the efficient heat transfer part is the flat-shaped silk of being made by pure red copper material, be wrapped on the plug (for example red copper bar) and make, red copper efficient heat transfer part is fixed on the tube sheet 5 by the stainless steel iron wire, has improved gas speed, has shortened the time of staying of formaldehyde gas in the high-temperature region, thereby reduced side reaction, contact with the heat exchange tube wall behind the efficient heat transfer part expanded by heating, fast reaction heat is passed to tube wall, improved heat transfer efficiency.
The lower end of heat exchanger tube 3 links to each other with lower perforated plate 18 by welding manner, the two ends of lower perforated plate 18 link to each other with oxidator main cylinder 2 by welding manner, be provided with hot water inlet 16 in the lower end of oxidator main cylinder 2, hot water enters in the oxidator main cylinder 2 from hot water inlet 16, with high temperature formaldehyde gas heat exchange in the heat exchanger tube 3 and produce steam, steam enters the steam net from steam (vapor) outlet 4.
Steam (vapor) outlet 4 is positioned at the upper end of oxidator main cylinder 2, and the position can make upper perforated plate 5 under water fully than upper perforated plate 5 height like this, helps overcoming cavitation erosion.
The catalytic oxidative dehydrogenations reaction takes place by catalyst layer 7 and generates the formaldehyde gas in the quaternary gaseous mixture, formaldehyde gas through with the hot water heat exchange after enter absorption system by formaldehyde gas outlet 19, oxidator main cylinder 2 passes through vessel flange 17 sealing and fixing together with skirt 1.
Fig. 2 A and Fig. 2 B shown upper perforated plate 5 inferior flat tube plate structure and with the connection state of oxidator main cylinder 2.The making of inferior flat pipe is by flat tube sheet being carried out the spinning operation, make it that certain plastic deformation take place, forming the tube sheet with certain radian; Upper perforated plate 5 links into an integrated entity by the mode of welding with the inwall of oxidator main cylinder 2.
The connection state of top cover 22 and oxidator main cylinder 2 as shown in Figure 3.Oxidation reactor top cover 22 passes through flange 14 sealing and fixing together with oxidator main cylinder 2, and oxidator main cylinder 2 is 1400mm with the diameter of top cover 22, and upper perforated plate 5 is 650mm to the distance of case top.When catalyst changeout more, only need the oxidator top cover is laid down, the operator stands in the housing catalyst of just mating formation easily outward, operates and need not enter in the housing.
The structure of efficient heat transfer part and with being connected as shown in Figure 4 of other parts, wherein the efficient heat transfer part is to be wrapped on the plug (for example red copper bar) 21 by the flat-shaped silk 20 that pure red copper material is made to make, red copper efficient heat transfer part is by tying up to red copper bar 21 top fix in position on the stainless steel wire on the upper perforated plate 5 24, improved gas speed, shortened the time of staying of formaldehyde gas in the high-temperature region, thereby reduced side reaction, contact with the heat exchange tube wall behind the efficient heat transfer part expanded by heating, fast reaction heat is passed to tube wall, improved heat transfer efficiency.
The structure of oxidator top cover 22 as shown in Figure 5, wherein said top cover 22 comprises: by the insulation jacket 12 that inner barrel 11 that is tightly connected and outer cylinder body 23 are formed, this insulation jacket 12 forms heating interlayer between described outer cylinder body 23 and inner barrel 23; Enter the quaternary gaseous mixture inlet 8 of top cover 22 inside from outer cylinder body 23, the inner barrel 23 of insulation jacket 12; And be used for be evenly distributed on described catalyst layer 7 lip-deep distribution awls 10 from the quaternary gaseous mixture inlet 8 quaternary gaseous mixtures that enter, this distribution awl 10 is a hollow, its lower end is fixed on inner barrel 11 inwalls.
The structure of this top cover 22 can be eliminated because of the condensation of the quaternary gaseous mixture influence to catalyst.Because quaternary gas makes the mist temperature reach 100 ℃, 64.2 ℃ of the boiling points of methyl alcohol through preheater; The driving initial stage (igniting before) for fear of the condensation of methanol gas cause the out-of-flatness of catalyst surface and condensation methyl alcohol to cause incomplete combustion and in the catalyst carbon distribution influence conversion ratio, make the top cover of quaternary gas, thereby avoided causing the reason of these unfavorable factors by heating.
Can find that from the above description the utility model can reach following technique effect:
1, eliminated the influence of the condensation of quaternary gaseous mixture, improved the efficient that oxidative dehydrogenation generates formaldehyde gas takes place catalyst;
2, overcome the stress cracking phenomenon that high temperature difference causes well, solved the stress corrosion problem that long-term puzzled technical staff does not have the oxidator waste heat boiler section of solution;
3, make things convenient for the replacing of catalyst;
4, improve the heat transfer efficiency of heat-exchange tube, thereby improved the exchange efficiency of heat exchanger.
Above-mentioned illustrative purposes only is used to illustrate the utility model, and is used for limiting scope of the present utility model.Scope of the present utility model is defined by claims.