WO2006106019A1 - Method of filling apparatuses with solids - Google Patents

Abstract

The invention relates to a method for filling chemical production apparatuses with solids using a controllable metering means and also a mobile device for carrying out the method. The device is suitable in particular for filling heat exchangers, absorption columns, distillation columns or tube bundle reactors with solids.

Description

 Process for filling apparatus with solids

The invention relates to a method for filling apparatus used in chemical production with solids using a controllable metering device and a locally displaceable

Apparatus for carrying out the method. The device is particularly suitable for the filling of heat exchangers, absorption columns, distillation columns or shell-and-tube reactors with solids.

The uniform filling of solids in pipes, tube bundles or heat exchangers is of crucial importance for the power efficiency of these devices. The solids may be, for example, packing such as Raschig rings, ceramic balls or catalysts and have different compositions and geometries such as those of balls, solid cylinders, hollow cylinders or rings.

From the prior art methods and apparatus for filling tubular reactors with shaped catalysts are known.

US Pat. No. 4,402,643 and EP 0 904 831 B (US Pat. No. 6,170,670 B1) describe the supply of granular material and the associated devices, the material being transported via a vibrated channel into the tubes to be filled.

Finely divided dust thereby falls in accordance with EP 0 904 831 through the sieve-shaped bottom of the channel into a separate container.

For example, be shaped catalyst bodies in the

Destroyed filling or damaged, the resulting catalyst bed is no longer homogeneous. Fine abrasion (dust) and catalyst breakage lead to the formation of cavities and channels, so that uneven flow through the tube leads to decreased or increased pressure drops. This affects the power efficiency or throughput of the apparatus.

According to the state of the art, although dust is screened off, it does not prevent dust nuisance. By this method, the dust adhered to the catalyst grains is not separated as well.

This problem is solved according to the invention.

The invention relates to a method for filling pipes with solids, in which one discharges the solid from a hopper (2) on an inclined plane with Rüttelrinnen (4), which is arranged in an approximately horizontal position and from the discharge opening of the

Funnel extends at least for connection to the downpipe (5) or a flexible hose connection through which the solid is fed to the pipe to be filled, characterized in that one respectively

a) adjusts the height of the outlet pipe (6) attached to the downpipe (5) in a suitable manner,

b) through a suction pipe (10) and a suction device (1), which are in close proximity to the hopper (2) and the outlet pipe (6), and applying a negative pressure sucks dust, and

c) after filling the tubes on rollers or rollers

(11) stored device for filling additional tubes moves.

In this case, the solid is metered in a uniform manner by controlling or regulating the vibration frequency of the vibrating trough (4). The metering or metering rate can also be adjusted if necessary simultaneously via the height-adjustable flow regulator (3), which has the shape of a weir.

The height-adjustable downpipes or the flexible hose connections prove to be particularly advantageous because even small differences in the height of the pipes to be filled are compensated and gaps between downpipe and reactor tube can be avoided.

For the solids to be filled with a medium

Particle size of preferably at least 1 mm may be moldings of various types and suitability such as Raschig rings, ceramic balls, inert body or shaped catalysts z. B. in the form of granules extrudates or compacts in the commercial dimensions.

Reactions with such catalysts include, for example, the preparation of ethylene oxide, phthalic anhydride, acrolein, acrylic acid, methyl mercaptan, hydrogen sulfide and others.

The aim of the invention is to obtain a homogeneous solid bed and to avoid mechanical destruction of the solids. Advantageously, with the method described here, a zonewise filling of the solids can be achieved, so that along the axial profile of the tube different fillings of solids with precisely defined volumes can be introduced simultaneously. When applied to a plurality of tubes (eg n = 2-100000), the method according to the invention is characterized by a uniform distribution of the filling heights so that when the tubes are exposed to a constant gas flow, differential pressure pressures with a mean standard deviation from the mean value of generally less than 10% result. At the same time a dust nuisance in the filling process should be avoided.

According to the filling of the solid body by means of a device as shown in Figures 1 and 5. With a device according to the invention x tubes (x = 1-50) can be filled simultaneously. Figure 1 shows, for example, a device with the simultaneous x = 5 tubes can be filled. For this purpose, the amount of solids to be filled for each reaction tube is first determined volumetrically or gravimetrically and placed in a collecting vessel. Preferably, the amount to be filled is determined gravimetrically. The collecting vessel has at least the volume of solids to be filled. The collection vessel is opened and introduced with the opening down into a hopper 2. The solids are first loosened by a device by means of vibrations, set in vibration and translational movement and fed via an inclined plane 4 (vibrating channel) evenly to a metering device. The number of channels on the inclined plane corresponds to the number of pipes to be filled at the same time. The metering device is connected to the apparatus to be filled (for example, reaction tube in tube bundle reactors) via height-adjustable downpipes 5 and allows a lossless supply of solids by means of a in the

Height-adjustable outlet pipe 6. As a metering device find use that allow a direct connection between the apparatus for the backfilling of solid beds and the apparatus to be filled. Suitable for this are funnels, pipes and flexible hose connections. These metering devices are preferably designed as length-adjustable downpipes (5 and 6) or flexible hose connections, so that there is a continuous connection between the apparatus to be filled (for example tube-bundle reactor) and the metering device. This allows the Solid particles without scattering losses or dosed into the apparatus to be filled. Furthermore, the dust emission is minimized during the filling process. Figure 1 shows that in spatial proximity to the hopper and the height-adjustable downpipes ever a connection for a suction device 1 and a suction pipe 10 is provided, are sucked on the possibly by applying a vacuum occurring dust and solid particles.

For the filling process it is crucial that the

Solid bed in a uniform, slow and reproducible mass flow is fed to the apparatus. This apparatus may be a heat exchanger, an absorption column, a distillation column and a tube bundle reactor. Particularly preferred

Tube bundle heat exchangers, which are used as reactors. These reaction tubes may also have internals (e.g., thermocouples). The device according to the invention allows a control of the mass flow via a variation of the vibration frequency of the apparatus advantageously via an electric thyristor control 7. A regulation of the mass flow is also possible via the height-adjustable flow regulator 3 at the transition from the hopper to the Rüttelrinnen. The solid bed should be characterized by a uniform

Oscillation movement of the collecting container, the inclined plane and the metering device are supplied to the apparatus. Advantageously, a collecting device (hopper) for the solid filling, a feeder (inclined plane) and a

Dosing device housed in an apparatus. Up to 50, preferably up to 20, of these devices can be integrated in one metering device in order to efficiently fill a plurality of pipes at the same time. Figure 1 shows, for example, a device with which 5 tubes can be filled simultaneously. By the simultaneous Backfilling of several pipes ensures a reproducible, even filling. For dosing, it is expedient to use up to 50 dosing units (x = 1-50), particularly suitable are 1 to 10 dosing units (x = 1-10) in an allocation device.

Ideally, the solids are set in motion by vibration of an inclined plane. Of particular importance in this case is the exact and fine adjustment of the vibration in order to keep the flow rate as uniform as possible. This requirement is achieved by commercially available electric vibrator motors. A variation of the vibration frequency via an electronic control, allows influencing the vibration intensity of the solid and thus their outflow speed. For example, Figures 1 and 4 show a lopsided pathway with an array of n = 5 troughs that can be simultaneously vibrated. Advantageously, this plane is terminated by a preferably transparent cover (e.g., plastic) to prevent loss of solids and dust emissions.

Advantageously, in the vicinity of the openings of the metering device, a pipe opening 10 is provided which, connected to a suction device, ensures removal of solid dusts and impurities.

Ideally, the apparatus is mounted on rollers or rollers 11 so that it can be operated and moved by one person at a time. For easy handling of the apparatus, the roller can be adjusted in height.

With the aid of the described method it is possible to keep the fluctuation of the dosing of the solids of generally less than +/- 5%. Examples

Example 1:

Structure of the filling machines (Figure 1-6):

a) The filling machine is structured as follows:

• Extraction on the upper part (1) of the filling machine and on the outlet pipes (10).

• Five hoppers (2).

• Gate valve (3) with wing nuts at the outlet to the vibrating channel (4) for adjusting the flow rate (height-adjustable flow regulator).

Rüttelrinne (4) over which the catalyst in the downpipes (5) is conveyed.

• Potentiometer (7) for adjusting the vibration level of the vibrating plate.

• An adjustable roller (11).

• Two handles (8, 9).

• Extensions of outlet tubes (6) with wing nuts and tapered outlet fitting into the tubes of the reactor.

b) Setting and optimizing the filling time at the filling machines:

• The filling machine is placed over the pipes to be filled.

• In general, the filling time can be set via two parameters: • By means of the adjustable height butterfly valve with wing nuts 3, at the outlet to the vibrating plate,

• Via a potentiometer 7, which controls the vibration of the outlet channels.

It is expedient to roughly adjust the opening of the outlet with the wing nut 3 and to carry out the fine tuning via the potentiometer 7. The first fillings are used to further optimize the machine. The fill level is used to check the correct filling of the pipes. If the pipe is too high, the machine is too fast, or if the pipe is too low, the machine will feed the catalyst too slowly into the pipe. In both cases, the filling speed is readjusted with the two above-mentioned parameters so that the tubes are filled as homogeneously as possible.

Backfilling the catalyst:

Preferably, the solids are filled in zones, so that along the axial profile of the reaction tube different fillings of solids with precisely definable filling heights, filling volumes and masses are introduced simultaneously.

Reaction tubes containing internals to control the reactor are preferably filled so that at least one catalyst particle is metered into the tube per second, thereby avoiding the formation of dead zones and channels resulting in increased differential pressure loss.

The feed roller 11 of the filling machine is adjusted so that after each filling of a row, the machine can be easily pushed forward. The catalyst to be filled is packed in collecting vessels, eg cans (1 can / tube).

The invention also relates to a locally displaceable device for filling pipes with solids, comprising

a) a hopper (2) to store the solid,

b) an inclined plane arranged thereon with grooves (4) which are arranged in an approximately horizontal position and extending from the discharge opening of the funnel to at least for connection to the downpipe (5), through which the solid is supplied to the pipes to be filled , characterized in that

c) the height of the outlet pipe (6) connected to the downpipe (5) can be adjusted,

d) a suction pipe (10) and a suction device (1) in close proximity to the hopper (2) and the outlet pipe (6) vacuum applied and dust can be sucked, and

e) the device is mounted on rollers or rollers (11).

The cross section of the downpipe is at most equal to the cross section of the pipe to be filled. It preferably has a smaller cross-section and tapers at its ends, so that it fits into the tube to be filled.

Brief description of the figures

Figure 1 shows an arrangement according to the invention (side view) of an allocation device for the simultaneous filling of five tubes with granular solids. Figure 2 shows an inventive arrangement of the hopper and the connection for a suction device of an allocator for the simultaneous filling of five tubes with granular solids (top view).

Figure 3 shows an inventive arrangement of the downpipes and the height-adjustable outlet of an allocator for the simultaneous filling of five pipes with granular solids (front view).

Figure 4 shows an inventive arrangement of the vibrating troughs of an allocating device for the simultaneous filling of five tubes with granular solids (top view).

Figure 5 shows an arrangement according to the invention (side view) of an allocation device for filling a pipe with granular solids.

Figure 6 shows an arrangement according to the invention (top view) of an allocation device for filling a pipe with granular solids.

The characters in the pictures mean:

1) Connection for suction device

2) Hopper

3) height-adjustable flow regulator

4) inclined plane with vibrating channel (s)

5) downpipe 6) height adjustable spout (wing nut)

7) control box

8) Carrying handles

9) push handle

10) suction tube 11) height-adjustable travel roller

Claims

claims 1. A method for filling pipes with solids, in which one discharges the solid from a hopper (2) on an inclined plane with Rüttelrinnen (4), which is arranged in an approximately horizontal position and from the discharge opening of the hopper to at least Connection to the downpipe (5) or a flexible hose connection extends, through which (s) the solid is supplied to the pipes to be filled, characterized in that one respectively a) the height of the outlet pipe (6) connected to a downpipe (5) is appropriately adjusted, b) by a suction pipe (10) and a suction device (1), which are in spatial proximity to the hopper (2) and the outlet pipe (6) applied negative pressure and sucks existing dust, and c) after filling the tubes, the device mounted on rollers or rollers (11) for filling further tubes moves. 2. The method according to claim 1, characterized in that solids are used with the geometry of balls, Volloder hollow cylinder, stars or rings. 3. The method according to claim 1, characterized in that the tube or plate heat exchangers, which are used as reactors, are filled. 4. The method according to claims 1 to 3, characterized in that the amount of solids to be filled for apparatus is first determined by volumetric or preferably gravimetric determination and the hoppers of Dispensing device is supplied loose or in collecting vessels, wherein advantageously the collection vessels remain in the hoppers. 5. The method according to claims 1 to 4, wherein simultaneously filled up to 50 apparatuses in parallel. 6. The method according to claims 1 to 5, wherein the feeding device is designed so that the hopper containing the solids to empty on an inclined plane, which has parallel passages (grooves) in the number of each to be filled reaction tubes and finished with a cover is. 7. The method according to claims 1 to 6, wherein the solids zoned in zones and introduced along the axial profile of the reaction tube different fillings of solids with precisely defined fill levels, filling volumes and masses simultaneously. 8. The method according to claims 1 to 7, characterized in that reaction tubes containing internals for controlling the reactor are filled so that at least one catalyst grain per second is metered into the tube. 9. The method according to claims 1 to 8, characterized in that adjusting the metered amount or metering rate of the solids to be filled via the height-adjustable flow regulator (3). 10. The method according to claim 1, characterized in that the allocation device is mounted on height-adjustable rollers or rollers so that they can be operated and moved by a person at the same time. 11. Locally displaceable device for filling pipes with solids, comprising a) a hopper (2) to store the solid, b) an inclined plane with Rüttelrinnen (4), which are arranged in an approximately horizontal position and extending from the discharge opening of the funnel to at least for connection to the downpipes (5) or a flexible hose connection by the (s) Solid is supplied to the pipes to be filled, characterized in that in each case c) the height of the outlet pipe (6) connected to a downpipe (5) can be adjusted, d) by a suction pipe (10) and a suction device (1) in spatial proximity to the hopper (2) and the outlet pipe (6), vacuum applied and dust can be sucked, and e) the device is mounted on rollers or rollers (11). 12. The device according to claim 11, wherein the cross section of the outlet pipe (6) is at most equal to that of the pipe to be filled. 13. The apparatus according to claim 11, wherein the outlet tube tapers at the end and this end has a smaller cross section than the tube to be filled. 14. The apparatus according to claim 11, wherein the crooked Level with the vibrating chutes is completed by a cover against dust discharge.