Catalytic reactor charging system and method for operation thereof

Abstract

A catalyst loading system for utilizing catalyst from a bulk supply located adjacent but not on the upper tube sheet of a catalytic reactor and for mechanized measuring of multiple identical quantities of catalyst and for mechanized loading of catalyst pellets into the reaction tubes of the reactor to achieve even drop rate, compaction and outage of the reaction tubes. From the bulk supply, multi-compartment catalyst charging hoppers are individually filled in rapid and accurately measured fashion by mechanized filling equipment having a predetermined sequence of operation that ensures accuracy of volumetric catalyst measurement. The charging hoppers are used for delivery of measured volumes of catalyst of a reactor tube loading mechanism which may take the form of a mobile cart framework being selectively positionable relative to the upper tube sheet and reaction tubes of a catalytic reactor to be charged with catalyst pellets. A pair of electronic vibrators are mounted to the cart framework and provide for support and vibratory movement of a vibratory tray having a catalyst feed hopper adapted to feed catalyst pellets to a plurality of generally parallel catalyst transfer troughs along which catalyst pellets are moved by vibration of the vibratory tray to a plurality of drop tubes. A compartmented hopper is fixed to the vibratory tray and controllably feeds catalyst pellets into respective catalyst transfer troughs. A plurality of charging tubes are connected to respective drop tubes by a plurality of elongate flexible tubes and are maintained in fixed, spaced relation by a structural element so as to define a charging manifold for simultaneous, timed delivery of catalyst pellets into a plurality of reactor tubes. The charging manifold has locator pins which are inserted into selected reactor tubes for orienting the charging tubes of the charging manifold with respect to a selected group of reaction tubes. A system is also provided for raising and lowering the charging manifold for efficiency of reactor tube charging operations. An electronic control system is effective for controlling the vibrators to achieve even drop rate from each of the catalyst transfer troughs and to control the vibrators responsive to catalyst weight to achieve even catalyst drop rate during an entire catalyst charging cycle.

Description

[0001] 1. Field of the Invention[0002] This invention relates generally to the controlled filling of the catalyst tubes of catalytic reactors with catalyst materials when the reactors are placed into service or when they have been cleaned of spent catalyst materials in preparation for further use in processes requiring catalytic reaction of flowing products of the process. More particularly, the present invention concerns a mechanized catalytic reactor charging system including a loading cart that is used by reactor servicing personnel and which is effective for efficient and controlled and simultaneous charging of a plurality of the reaction tubes of a catalytic reactor so that each of the plurality of reaction tubes will contain a precise measured quantity of the catalyst arranged in one or more layers and having a predetermined degree of compaction. Even further, the present invention concerns a mechanized catalyst loading cart having the capability for automatically adjusting th...

AI Technical Summary

Problems solved by technology

It is well known that each worker of a charging crew will typically pour catalyst pellets at a slightly different rate so that the result can often be poor drop time uniformity thus resulting in uneven tube outages.

In some cases the catalyst pellets will bridge within some of the reaction tubes due to non-uniform drop time and catalyst compaction, thus resulting in voids that cause "hot spots" and uneven fluid pressures and temperatures within the various tubes of the reactor.

The resulting chemical product from reactors that have not been uniformly charged with catalyst is often less than optimum quality.

This type of controlled filling achieves virtually the same catalyst bed height in each of the reactor tubes but it does not take into consideration the problem of catalyst pellet bridging and compaction within the respective reaction tubes.

Thus, though the upper end of the catalyst beds in the tubes can be virtually the same, voids within part of the reaction tubes which occurs by uncontrolled drop rate will result in uneven catalyst materials in the catalyst beds.

Further, this method does not provide for consistent drop rate of the catalyst so that uneven tube outage and non-uniform compaction can be the result.

This could result in the development of hot spots within the reactor which could be detrimental to reactor operation.

This apparatus has proved ineffective because the vibratory activity of the tray does not ensure precision control of the drop rate of the catalyst pellets from each of the feed grooves of the tray.

Use of this apparatus has been discontinued as ineffective for simultaneous loading of multiple catalytic reactor tubes.

Typically, catalytic reactors are loaded or charged by means of a highly labor intensive manual loading operation.

If the quantity input of the catalyst is exceeded, it is possible that the catalyst pellets can bridge within the tubes, thereby developing voids in the catalyst beds of some of the tubes and thus resulting in uneven outage at the upper ends of some of the tubes.

For example, the labor requirements for a manual catalyst loading operation add significant cost to the reactor and thus add to the cost of the resulting product.

This feature overcomes a disadvantage of the prior art, because a single vibrator cannot ordinarily be adjusted to provide even dispensing of catalyst pellets from each of the troughs of a vibratory tray.

For optimum delivery of catalyst pellets into a plurality of reaction tubes, a predetermined catalyst drop rate is established which is sufficiently high to achieve efficient production and is not high enough to result in bridging or improper compaction of catalyst pellets within respective reaction tubes.

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