DK201500657A1 - Catalyst Loading Method and Apparatus - Google Patents

Abstract

Catalyst particles are loaded into vertically mounted reactor tubes by means of a plurality of flexible loading hoses with an internal pattern slowing down the drop speed of the particles, as one reactor tube is being loaded, the next reactor tube is being prepared for loading, thus reducing the overall loading time of a reactor.

Description

Title: Catalyst Loading Method and Apparatus

The invention concerns a method and an apparatus for loading particulate material in reactor tubes. More particularly, the invention relates to loading of particulate, catalytic material in chemical reactors comprising a plurality of vertically arranged reactor tubes.

Loading of particulate, catalytic material in tubular reactors is known to be performed by providing a loading tube by connecting a number of tube section having an outer diameter smaller than the inner diameter of the reactor tube to a final tube length corresponding to length of the reactor tube, introducing at top of the loading tube a quantity of the catalyst particles to be loaded into the reactor tube, causing the catalyst particles to pass through the loading tube in a damped motion by providing dampening means within the tube side of the tube; and successively withdrawing the loading tube from the reactor tube in a length corresponding to loading height of the catalyst particles loaded into the reactor tube.

An apparatus to perform this method is also known and comprises a tubular member having a tube diameter to fit into a reactor tube, a top part of the tubular member is adapted to be connected to a funnel unit and a bottom part of the tubular member is provided with lifting means for withdrawal of the member from the reactor tube. The tubular member consists of separate tube section each provided with connecting means adapted to be assembled to the tubular member when connected to each other and being provided with damp ening means to decelerate speed of catalyst particles being passed through the tubular member.

This method is however time consuming and the apparatus to perform the method is expensive and complicated to manufacture .

US2008128045 describes an apparatus for loading particulate catalytic material into reactor tubes comprising an axial shaft capable of rotational movement around its axis in a clockwise and counter-clockwise direction and having attached at its lower end perpendicular to the axis a horizontal distribution shaft, the length of which can be varied, one end of a flexible hollow catalyst supply hose being attached to the end of the horizontal distribution shaft extending into the reactor space, the other end of the flexible catalyst supply hose being available for entrance of catalyst particles external to the reactor tube. The invention also concerns a method of loading particulate catalytic material into a reactor tube.

US2014290788 discloses an invention relating to a method for filling a multi-tube catalytic reactor and to a set of inserts suited to implementing this method. The method of the invention is based on the use of inserts of different types allowing superposed layers of catalysts to be placed in the reaction compartments. The heads of the inserts are visually distinct according to the type of insert, making it possible to avoid filling errors and thus allowing the various layers of catalyst to be filled reliably and simultaneously on a reactor scale.

US2003031536 concerns a method of loading particulate catalytic material into a reactor tube and a loading apparatus for use in the method. The method comprises providing a loading tube through which catalyst particles pass in a damped motion. The dampening means are provided by mounting a spirally formed body on the inner wall of each tube section. The spirally formed body is formed from a rod having an arbitrarily shaped cross-section. The spirally formed body in each section has a pitch, with respect to the diameter of the tube section, in the interval of 2-8.

US patent No. 5,247,979, describes a method for filling particulate material into a vertical tube using a line with a damper in the form of a series of flexible, damper brushes arranged transversely to the line. The line with damper brushes is first lowered into the vertical tube, and then the particles are poured into the tube. It is stated that quick, even and reproducible filling is attained if the line is jerked a little during the filling operation, while simultaneously being lifted up gradually as the tube is filled.

Despite the methods described in the above mentioned prior art, there is a need for a method and an apparatus for loading of catalytic particle material into reactor tubes which is fast, cheap and gentle in handling of the particles .

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a method for filling particulate, catalytic material in chem ical reactors comprising a plurality of vertically arranged reactor tubes.

It is also an object of the invention to provide a fast, cheap and safe loading apparatus applicable to loading of particulate, catalytic material in chemical reactors comprising a plurality of vertically arranged reactor tubes.

The above objects are achieved by the invention, which is a method of loading catalyst particles into a plurality of vertically mounted reactor tubes. First a plurality of flexible loading hoses is provided to a reactor with vertical reaction tubes to be loaded. The flexible loading hoses need to have an outer diameter smaller than the inner diameter of the reactor tubes to be loaded in order to enable the flexible loading tubes to be inserted into the reactor tubes. Further, the flexible loading hoses must each have a hose length which is as long as the reactor tube to be loaded plus any length necessary to protrude from the top of the reactor tube during loading to enable the flexible loading hose to be connected to other loading equipment.

The flexible loading hoses have an internal pattern which is able to decrease the velocity of the catalyst particles as they fall down inside the loading hose in order to protect them from being damaged when they exit the loading tube and settle at the bottom of the reactor tubes, or at the top of the already loaded catalyst inside the reactor tubes. The internal pattern on the loading hoses can be in the form of an inside protruding spiral serving to damp the downwards motion of the catalytic particles, but any internal dampening pattern such as ridges, dots, S-shapes or the like may be applied.

When the plurality of flexible loading hoses has been provided, they are inserted one by one into the reactor tubes which are to be loaded with catalyst particles. The length of each of the flexible loading hoses is adjusted so the lower end of the hose hangs a distance from the bottom of the reactor tube which is as large as possible without considerable risk of damaging the catalyst particles because of the free drop from the lower end of the flexible loading hose where the particles downward motion is not dampened. This distance may vary with different types of catalyst particles. When inserted to the tubes, a first of the flexible loading hoses is connected to a catalyst loader. The catalyst loader may be any kind known in the art. In one embodiment the catalyst loader comprises a hose connecting part, a funnel, a compartment for taking up a quantity of catalyst particles and a mechanism adapted to move the catalyst particles in a steady stream down the funnel and the flexible loading hose at a fixed loading speed. In an embodiment this mechanism may be a vibrator. The loading speed can be varied. A high loading speed is preferable, but the speed is limited by the size and shape of the catalyst particles, the inner diameter of the reactor tubes and thus the inner diameter of the flexible loading hoses to name some of the parameters.

When the first flexible loading hose is connected to a catalyst loader and the loading of a first quantity of catalyst particles into a first reactor tube has commenced, a second of the plurality of the flexible loading hoses is then connected to a further catalyst loader and the above mentioned procedure is repeated while the first reactor tube is still being loaded. This procedure is repeated for a number of flexible loading hoses, reactor tubes and catalyst loaders, while the loading of the first catalyst tube is still ongoing. Thus, the operator or operators can continue with the loading procedure without idle time, even though each catalyst tube demands a notable time period for a quantity of catalyst particles to be loaded. Expensive idle time for the operator as known from other loading procedures is thus avoided and more important the overall loading time for all the reactor tubes is considerably decreased .

After inserting a number flexible hoses to reactor tubes and consecutively starting catalyst loading of those tubes, the first quantity of catalyst particles have finished being loaded into the first reactor tube. Then the flexible loading hose can be retracted from the first reactor tube and be inserted to a next reactor tube which still needs to be loaded with a first quantity of catalyst particles, and the loading of this next reactor tube can proceed as already described. This is consecutively done for all the reactor tubes one by one as a flexible loading hose and catalyst loader has finished loading a first quantity of catalyst particles, until all the reactor tubes are loaded with a first quantity of catalyst particles.

As all the reactor tubes are loaded with a first quantity of catalyst particles, a first bed of catalysts are in the reactor tubes and the distance from the surface of this catalyst bed to the top end of the reactor tubes is smaller than the distance from the bottom the reactor tubes to the top of the reactor tubes. Hence, to continue filling cata- lyst particles into the reactor tubes, the flexible loading hoses have to be shortened accordingly. Each of the flexible loading hoses is retracted from the reactor tube it has just loaded, and a length of each of the loading hoses is cut off before it is again inserted to a reactor tube to commence loading of a second quantity of catalyst particles according to the procedure already described in the above text. As described, the length which is cut off is as long as possible in consideration of the free fall height of the catalyst particles before they reach the catalyst bed already loaded, so the catalyst particles are not damaged.

The quantity of catalyst particles which is loaded in each loading sequence is measured so it corresponds to the distance between the catalyst bed already loaded up to the lower end of the flexible loading hose. These loading steps are repeated for all the reactor tubes and loading hoses until all the reactor tubes are loaded with the desired amount for catalyst particles, forming a catalyst bed relevant for the process to be carried out in the reactor.

When catalyst particles are loaded through the loading tube, the speed of the catalyst particles is reduced as the catalyst descends in a spiral movement on the spiral. At the bottom of the loading tube, the catalyst particles have the same speed, and fall a short, pre-defined distance. The result is uniform dense loading with no broken catalyst particles .

A further embodiment of the invention is an apparatus suited for loading of catalyst particles to vertically mounted reactor tubes according to the method described in the foregoing.

The loading apparatus comprises a plurality of flexible loading hoses having an outer diameter smaller than the inner diameter of the reactor tubes. The top part of the flexible loading hoses is adapted to be connected to a catalyst loader. The catalyst loader may comprise a connection section adapted to be easily mounted to the top part of the flexible loading hoses, a funnel which enables the catalyst particles to pass from the catalyst loader into the flexible loading hose it is connected to, a compartment which can hold an amount of catalyst particles at least as big as the quantity of catalyst particles which can be loaded into the reactor tubes in one pass and a conveying mechanism such as a vibrator which enables the catalyst particles to move from the catalyst loader to the flexible loading hose in a controlled fashion and a set speed which is suitable for the catalyst particles to be loaded.

The flexible loading hoses have an initial length which is corresponding to the length of the reactor tubes. This means that the flexible hoses must have a length which is as long as the reactor tubes, plus any length which is necessary to protrude out from the top of the reactor tubes for handling and connection to the catalyst loader and minus the length of the free fall of the catalyst particles when exiting the bottom of the flexible loading hoses before they react the bottom of the reactor tubes. As mentioned, this free fall distance is selected with consideration of the characteristics of the specific catalyst particles so they are not damaged because of the free fall. The longer the free fall, the greater the speed of the catalyst particle before it reaches the bottom of the reactor tubes and thus the greater the risk of damaging the catalyst particles .

The flexible loading hoses have an internal pattern which decreases the speed of the catalyst particles as they travel down inside of the flexible loading hoses by means of gravity .

The internal pattern may be of any suitable kind. It may be an internal helical protrusion, which provides for a spiral movement of the catalyst particles downwards. The flexible loading hoses may be made of a soft rubber-like material which further lowers the risk of damaging the often brittle catalyst particles.

FEATURES OF THE INVENTION

1. Method of loading catalyst particles into a plurality of vertically mounted reactor tubes, comprising a) providing a plurality of flexible loading hoses having an outer diameter smaller than the inner diameter of the reactor tube and each with an initial hose length corresponding to the length of the reactor tubes and with an internal pattern which decreases the velocity of the catalyst particles as they are loaded into the reactor tubes; b) inserting one of the flexible loading hoses into the top end of a reactor tube; c) connecting the top end of said flexible loading hose to a catalyst loader; d) introducing to said catalyst loader a first quantity of the catalyst particles to be loaded into the reactor tube; e) loading said quantity of catalyst into said reactor tube by the catalyst loader, via the flexible loading hose at a fixed loading speed; f) repeating step b) to e) for a number, of flexible loading hoses and reactor tubes while the first reactor tube is being loaded; g) when said first quantity of catalyst particles has been loaded into said first reactor tube, retracting the flexible loading hose from the first reactor tube, and repeating step b) to f) for the remaining reactor tubes, until all the reactor tubes have been loaded with a first quantity of the catalyst particles; h) retracting the flexible loading hose from the reactor tube, cutting off a length of the flexible loading hose and repeating step b) to e); and i) repeating step b) to h) until the loading of the reactor tubes is finished.

2. Method according to feature 1, wherein the cut off length of the flexible loading hose corresponds to the height of said quantity of catalyst particles when loaded into said reactor tube.

3. Method according to any of the preceding feature, wherein said internal pattern is a helical internal protrusion in said flexible loading hose.

4. A loading apparatus for loading catalyst particles into a plurality of vertically mounted reactor tubes comprising a plurality of flexible loading hoses having an outer diameter smaller than the inner diameter of the reactor tubes; and a top part of the flexible loading hoses adapted to be connected to a catalyst loader, where the flexible loading hoses have an initial hose length corresponding to the length of the reactor tubes and with an internal pattern which decreases the velocity of the catalyst particles as they are loaded into the reactor tubes .

5. Loading apparatus according to feature 4, wherein said internal pattern is a helical internal protrusion in said flexible loading hoses.

DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a flexible loading hose 01 to be used for loading of catalyst particles in vertically mounted reactor tubes according to the invention. The flexible hose is simple and cheap in production and can therefore be used as a one-time use flexible loading hose which is important as the flexible loading according to the invention is consecutively cut to a smaller and smaller length as the loading of catalyst proceeds.

The flexible loading hose has an internal helical protrusion 02, which serves to dampen the falling speed of the catalyst particles as they fall down inside the flexible loading hose when loading the reactor tubes.

Claims (5)

1. Method of loading catalyst particles into a plurality of vertically mounted reactor tubes, comprising a) providing a plurality of flexible loading hoses having an outer diameter smaller than the inner diameter of the reactor tube and each with an initial hose length corresponding to the length of the reactor tubes and with an internal pattern which decreases the velocity of the catalyst particles as they are loaded into the reactor tubes; b) inserting one of the flexible loading hoses into the top end of a reactor tube; c) connecting the top end of said flexible loading hose to a catalyst loader; d) introducing to said catalyst loader a first quantity of the catalyst particles to be loaded into the reactor tube; e) loading said quantity of catalyst into said reactor tube by the catalyst loader, via the flexible loading hose at a fixed loading speed; f) repeating step b) to e) for a number, of flexible loading hoses and reactor tubes while the first reactor tube is being loaded; g) when said first quantity of catalyst particles has been loaded into said first reactor tube, retracting the flexible loading hose from the first reactor tube, and repeating step b) to f) for the remaining reactor tubes, until all the reactor tubes have been loaded with a first quantity of the catalyst particles; h) retracting the flexible loading hose from the reactor tube, cutting off a length of the flexible loading hose and repeating step b) to e); i) repeating step b) to h) until the loading of the reactor tubes is finished.

2. Method according to claim 1, wherein the cut off length of the flexible loading hose corresponds to the height of said quantity of catalyst particles when loaded into said reactor tube.

3. Method according to any of the preceding claims, wherein said internal pattern is a helical internal protrusion in said flexible loading hose.

4. A loading apparatus for loading catalyst particles into a plurality of vertically mounted reactor tubes comprising a plurality of flexible loading hoses having an outer diameter smaller than the inner diameter of the reactor tubes; and a top part of the flexible loading hoses adapted to be connected to a catalyst loader, where the flexible loading hoses have an initial hose length corresponding to the length of the reactor tubes and with an internal pattern which decreases the velocity of the catalyst particles as they are loaded into the reactor tubes .

5. Loading apparatus according to claim 4, wherein said internal pattern is a helical internal protrusion in said flexible loading hoses.