CN1016318B - Inner unit of direct heat-exchange synthetic tower - Google Patents

Abstract

The present invention relates to an internal component of a direct heat-exchange synthesizing tower, particularly to an internal component of a direct heat-exchange synthesizing tower for synthesizing ammonia and methanol. The present invention has the advantages of simple structure, convenient temperature regulation and high synthetic ratio; the internal component is composed of more than two layers of catalytic beds and a heat exchanger, wherein the catalytic beds are separated by a hot gas and cold gas mixer which is fixed on the wall of the internal component; an upper funnel-shaped mechanical device and a lower funnel-shaped mechanical device are composed of catalyst supporting sieve plates, lower conical gas blocking plates, etc. The present invention is convenient for loading and unloading the catalysts and can save overhauling time. The present invention is suitable for medium and small-sized production plants; the present invention can increase productivity, reserve a bearing outer cylinder of the original synthesizing tower in installation and save equipment investment.

Description

Inner unit of direct heat-exchange synthetic tower

The invention relates to and be used in the ammonia converter internals that carries out the gas-solid catalysis process, especially for synthesizing of ammonia or methyl alcohol.

The synthetic tower that is used for the catalytic synthesis process mainly contains three classes, and 1＞continuous inner heat exchange type also claims cooling pipe type; 2＞indirect heat exchange formula; 2＞direct heat exchange formula.

Direct heat exchange formula synthetic tower because temperature adjustment is convenient, can use under lower pressure in the synthesis ammonia plant or Methanol Plant of large-scale (producing daily more than the kiloton).In U.S. Pat 3475136(1969 October) in it is had detailed description.Simultaneously because this kind synthetic tower operating pressure low (about 150 crust), the catalyst volume is big, have that the catalyst utilization coefficient is low, ammonia net value is not high enough, synthetic tower is to the bad shortcoming of various technical process adaptability, the producer that abroad has begins to use instead the synthetic tower of indirect heat exchange structure or the modified version synthetic tower that indirect heat exchange structure and direct heat exchange structure are merged.Do not see as yet so far that abroad medium and small synthesis ammonia plant synthetic tower adopts the report of direct heat exchange formula structure.Yet but all adopt continuous inner heat exchange type synthetic tower (synthetic tower universal design (VSH version) Pg320Dg500～600 Shanghai Chemical Engineering Design Inst.) at medium and small synthetic ammonia of China or Methanol Plant; it has only a catalytic bed; because bed inner cool tube complex structure, pressure fall greatly; when the catalyst heating reduction, catalyst is reduced and oxidation repeatedly; thereby make catalyst reduce activity quickly, and gas leakage causing to stop production and change internals after the internal stress drawing crack of ammonia converter internals weld seam when often being expanded with heat and contract with cold.For this reason, the present inventor has proposed to be suitable for the synthetic tower of the novel direct heat exchange formula of large, medium and small type synthetic ammonia or methanol production in the patent application of Chinese patent CN871000963, its diameter has solved the shortcoming that above-mentioned two class synthetic towers exist between 0.5～5 meter.This column internals is made of the heat exchanger of catalytic bed more than 2 layers and bottom, and the diameter of synthetic tower is between 0.5～5 meter.Between catalytic bed, support catalyst and separate catalytic bed with cold and hot gas mixer, gas mixer is kept off outward under compression ring, cylindrical interior retaining compression ring, the taper by low temperature adjusting gas blowout head, level support sieve plate, taper and keeps off the subassembly that compression ring, gusset and air distribution plate seven part machineries are linked to be integral body, it is an active, can take out and pack into, it mechanically is fixed on the backing ring during operation operation.Through practice for many years, as long as the original peripheral equipment of many small-sized synthesis ammonia plants carries out less change, the output of synthetic ammonia can improve 30～60%, and economic benefit is very remarkable.But in the practical application that should invent, found some shortcomings, this synthetic tower is cumbersome when loading and drawing off catalyst, changes catalyst and will spend the more time, and the dead gas-bearing formation in pipe core top is higher in addition, and the utilization of high-pressure space does not also reach best condition.In view of the shortcoming that above prior art exists, the objective of the invention is to keep the advantage of an invention, its structure is carried out suitable improvement, invent a kind of ammonia converter internals that is fit to medium and small synthetic ammonia or methyl alcohol more, its diameter is between 0.45～1.6 meter.It is simple in structure, is easy to make, and is convenient to the loading, unloading catalyst, makes full use of high-pressure space, has improved throughput.

Ammonia converter internals of the present invention is the suitable catalytic synthesis that carries out ammonia or methyl alcohol, directly carry out the ammonia converter internals of heat exchange with axial flow, it is made of the two-layer above catalytic bed on top and the heat exchanger of bottom, it is characterized in that upper and lower two funnelform gas mixers that gas block panel etc. constitutes under cloth compression ring and the taper by the conical bearing sieve plate, in cylindrical are separated, cold and hot gas mixer directly is weldingly fixed on the internals wall, the internals diameter is between 0.4～1.5 meter, and suitable pressure is 200～300 crust.

Cold and hot gas mixer keeps off compression ring outward by gas block panel, taper under low temperature controlled atmosphere joint shower nozzle, the cone screen plate that supports catalyst, the taper and mechanically is connected as a whole with cylindrical interior cloth compression ring five parts.Their relative position is to be the cone screen plate of supporting catalyst on low temperature controlled atmosphere joint shower nozzle, the outside is that taper keeps off compression ring outward, the inside is cylindrical interior cloth compression ring, be gas block panel under the taper below, they are mechanically linked together becomes the integrally combined part, constitute the funnelform mechanism up and down of conveniently assemble and disassemble catalyst, it is placed on the backing ring that is welded on the inwall, with the ring-type retaining plate single piece and internals wall are welded again.The diameter of the cylindrical cloth compression ring of gas mixer the inside is big more many than pipe core, can allow catalyst waltz through from top to bottom.

Feed low wet in the internals and be and enter respectively through the low wet inlet pipe of urceolus top cover that gas mixer is sprayed by shower nozzle between each catalytic bed, with enter gas mixer spatial thermal response gas phase from sieve plate and mix, enter the middle part through cylindrical cloth compression ring again, react from axially entering down one deck catalytic bed downwards.The thermopair of measuring each catalytic bed inserts from pass top cover fixed thermocouple sheath.

Silk screen location grid have been fixed in the welding of these internals, fix and shortened the distance of basket lid and the vertical silk screen of pipe core location grid, the grid middle part has increased the pipe core sleeve pipe, allow and shorten later pipe core and in sleeve pipe, can freely stretch, reason heat expansion and push up bad internals basket lid has not increased the capacity of catalyst simultaneously yet.

The present invention is used in keeping Chinese patent CN87100963 patent application the advantage of synthetic tower of medium and small factory, the present invention can also be applicable to the various flow processs of temperature raising type, hot-water type, classic (no recovery of heat), and it is that obvious improvement has been arranged that the synthetic tower of direct heat exchange formula more in the world only is adapted on this aspect of heating type process.Internals of the present invention have been improved block construction owing to fixed cold and hot gas mixer, and the loading and unloading catalyst is very convenient, has saved 2～3 days catalyst loadingunloading times, and are that 600 millimeters synthetic tower is that example is calculated with diameter, and one day the output value can reach 6～70,000 yuan.The present invention improves the top of internals, silk screen location grid are welded on the inner tube wall, fix the distance of it and internals basket lid, grid place, silk screen location, pipe core top has increased sleeve pipe, pipe core inside can freely stretch, avoided the heat expansion pipe core to push up bad basket lid, also shortened the distance between silk screen location grid and the basket lid simultaneously, can increase the height of catalyst layer, add that improve gas mixer also can adorn catalyst later on more, so the catalyst filling amount of internals has had more increase, has correspondingly improved synthetic output of column.

Now use a pictorial representation typical structure of the present invention:

Fig. 1 is the axial sectional view of synthetic tower;

In Fig. 1, internals 10 are installed in the pressure-bearing urceolus 11, internals 10 comprise 4 catalytic bed, wherein there is the structure of the cold and hot gas mixer between 12A, 12B, 12C, 12D four catalytic bed identical, all be to be welded on the inwall of internals 10 to fix, having only catalytic bed 12D supporting sieve plate 20D is the circular sieve plate of level, is processed with the hole that can pass pipe core above.

Three cold and hot gas mixing tank integrally combined parts of internals are by conical bearing sieve plate 20A, 20B, 20C, cylindrical cloth compression ring 26A, 26B, 26C, gas block panel 30A, 30B under the taper, 30C,, low temperature is regulated a gas blowout 22A, 22B, 22C, and taper keeps off compression ring 24A, 24B outward, five kinds of parts of 24C are formed.They be placed on respectively backing ring 14A, 14B, the 14C of catalytic bed last after, with ring-type retaining plate 28A, 28B, 28C cold and hot gas mixing tank is welded on the internals wall again.Backing ring is directly to be weldingly fixed on the wall of internals 10.Leave low temperature inlet pipe 32 on the cold and hot gas mixing tank, the perforation of thermocouple sheath 50.Pipe core 62 with cylindrical in the gap of cloth compression ring can allow catalyst be easy to by.38 is the tubulation heat exchanger, and 36 is traverse baffle.

Silk screen location grid 66 and pipe core sleeve 64 connect together, and are fixed on internals 10 barrels.Pipe core 62 can freely stretch in sleeve 64.

The example that ammonia converter internals of the present invention is used for the ammonia synthesis process process may further comprise the steps:

＜1〉the internals 10 of the present invention pressure-bearing urceolus 11 of packing into, the pressure-bearing urceolus can adopt the original equipment urceolus, process top cover in addition.Pressing Fig. 2 and external system pipeline connects.

＜2〉acquisition of the synthetic gas in the technological process of building-up reactions can be adopted known arbitrary suitable gasification and the gas that obtains, passes through a series of scavenging process again, just can obtain needed qualified synthetic gas.

＜3〉synthetic gas is operated by Fig. 2 or other technical process, circulator outlet 40, the temperature of synthetic gas is 35 ℃, and pressure 300 crust are formed and listed in table 1, below described according to Fig. 2, the reaction gas temperature that exports 46 places to the synthetic tower secondary is 290 ℃, and pressure is 295 crust, and gas composition is as shown in table 1, at this moment the pressure drop of reactor is 5 crust, and ammonia net value is 16.49%.The diameter of the employed synthetic tower of this example is 0.6 meter, the iron catalyst that the catalyst of catalytic bed adopts synthetic ammonia to use always.(seeing Table 1)

Table 1

Tolerance component P T

Kmol/hr H2% N2% CH4+Ar NH3% crust ℃

Synthetic tower import 1,409 57.5 20.5 20 2 300 35

Synthetic tower exports 1,213 42.5 15.8 23.2 18.5 295 290

Claims (3)

1, direct heat exchange formula ammonia converter internals, a kind of suitable carry out ammonia or methyl alcohol building-up reactions with axial flow direct heat exchange formula ammonia converter internals, it is by top catalytic bed (12) more than 2 layers to be arranged, the bottom is constituted by heat exchanger (38), the internals diameter is between 0.4～1.5 meter, and suitable pressure is 200～300 crust, supports catalyst with cold and hot gas mixer between catalytic bed, and separate two catalytic beds, it is characterized in that cold and hot gas mixer directly is welded on the internals wall.

2, ammonia converter internals according to claim 1, it is characterized in that cold and hot gas mixer is by low temperature controlled atmosphere joint shower nozzle (22), the cone screen plate (20) of supporting catalyst, taper keeps off compression ring (24) outward, cloth compression ring (26) in cylindrical, gas block panel (30) five parts mechanically connect into as a whole under the taper, their relative position is to be the cone screen plate (20) of supporting catalyst on low temperature controlled atmosphere joint shower nozzle (22), the outside is that taper keeps off compression ring (24) outward, the inside is cylindrical interior cloth compression ring (26), bottom is gas block panel under the taper (30), they are mechanically linked together becomes the integrally combined part and is placed on the backing ring (14), constituted be convenient to load and unload catalyst on, following two funnelform mechanisms use ring-type retaining plate (28) to be welded on the internals wall then.

3, ammonia converter internals according to claim 2, it is characterized in that welding fixed silk screen location grid, fix and shortened the distance of basket lid and the vertical silk screen of pipe core location grid, increased the pipe core sleeve pipe in the middle of the grid, allow pipe core retractable in sleeve pipe after shortening, reason heat expansion and push up bad basket lid has not increased the capacity of catalyst simultaneously yet.