MXPA97005104A - Horizon regenerative thermal oxidizing unit - Google Patents

Abstract

The present invention relates to a horizontal thermal regenerative oxidant unit comprising a combustion chamber connected to two heat regenerating units that house the thermal collector means, further characterized in that each unit comprises at least the first and second compartments in vertically stacked relation with connection steps such that the gases passing through them pass horizontally in a first direction through the first unit and then subsequently in the reverse direction through the second unit.

Description

THERMAL OXIDIZING UNIT REGENEROTIVR HORIZONTAL BACKGROUND OF THE INVENTION This invention relates to thermal regenerative units and specifically to units designed for efficient use. of the recirculated heat in the thermal oxidizers, in which a horizontal arrangement allows a very efficient utilization of the space. Many chemical and petrochemical procedures result in an emission of exhaust gases containing volatile organic components (referred to in the industry as "VOCs"), many of which are believed to be harmful at the same time. There has therefore been a combined effort to eradicate such errusions through the motion of VOCs before releasing the gases from the atmosphere to the atmosphere. Through cornbus + ion cores in which they are mixed with fuel and burned, to make this process more efficient, the generated heat is typically used to preheat the incoming gases containing VOCs, which is done in a thermal regenerative unit. In such a unit, the gases emitted by the combustion chamber pass through a receiver which contains thermal collector means that absorb the heat of combustion.When the thermal collector means have reached the desired temperature, the flow and the incoming gases pass through heated media and the gases emitted pass through a second container of thermal collector media. as the heat1 extracted from the exhaust gases reaches the desired level. Such procedures are considerably economic and reduce the costs of operating such regenerative units. However, since the units are typically added to the existing equipment as it is modernized to meet the new environmental standards, they must often be adapted to the existing available space instead of being designed as part of the installation before it is constructed. . As indicated above, the space must be distributed for double passages through which the exhaust gases can reach the combustion chamber and this is not easy to accommodate except by installing vertical towers for heat exchange. However, since the thermal collector material must be changed from time to time, the maintenance of such towers is a serious problem. A horizontal thermal regenerative oxidizer unit has been developed that occupies comparatively little space and is easily maintained adapted to use * modular thermal collector units that are installed and removed without difficulty.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a horizontal thermal regenerative oxidizing unit comprising a combustion chamber connected to two heat regenerating units housing thermal collector means wherein each unit comprises at least the first and second comparisons relative to the vertical It is only stacked with connection steps such that the gases passing through them pass continuously in a first direction through the first unit and then subse- quently in the reverse direction through the second unit. The heat regenerating units may comprise, if more than two compartments are stacked one on top of the other, passing the exhaust gases horizontally in alternating directions as it rises (or ba) through the exhaust pipe. Generally, however, two are preferred per unit. The compartments are preferably adapted to house the thermal collector means in the form of porous ceramic blocks with a multitude of oblique steps. These are sometimes referred to as "honeycomb monoliths". Such monoliths are easily installed and removed with modules, and the comparisons of the thermal regenerative units are preferably designed to receive such monoliths and thus allow their easy maintenance.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated by the following d. Figure 1 is an exploded view, partially in section cut away showing one embodiment of the invention. Figure 2 is a plan diagram of the equipment illustrated in Figure 1, with the arrows indicating the direction of gas passage in the first operating mode. Figure 3 is similar to Figure 2 except that the gas arrow is reversed to illustrate a second mode of operation.

DETAILED DESCRIPTION OF THE INVENTION The invention is now described in more detail with specific reference to the drawings. These illustrate a preferred embodiment of the horizontal thermal regenerative oxidant unit according to the invention but it should not be considered that any limitation should be inferred on the essential scope of the invention claimed herein. In figure 1, the process gas containing VOCs enters through conduit 1 and feeds first distributor passage * 2, equipped with valves 3, allowing flow in one direction but not in the opposite direction, depending on which of the valves is in the open position. In Figure 2, the valve on the left is closed, while in Figure 3 it is the valve on the right that is closed. The gas enters the first heat transfer unit 4 from the distributor passage through a compartment 5 of the lower level, which contains a honeycomb monolith 6. From this compartment the gas reverses the direction and enters a compartment 7. from the upper level of the unit, which also contains a honeycomb monolith. The gas passes directly from the compartment of the upper level * to the combustion chamber 8, where it is subjected to temperatures that result in combustion of the VOCs. The gas emitted by the combustion chamber enters a second thermal regenerative oxidant unit 4 ', through a combustion 7' of the upper level and then, moving the direction, enters a lower 5 'compartment. Both the upper and lower compartments house 6 'honeycomb monoliths. From the lower compartment, the gas enters a second distributor pipe 8, which has the valves 9 ', allowing the gas entering the second distributor pipe to exit only through the exhaust hole 10, from which it is extracted by a pump 11 and emitted through an exhaust pipe 1? .. In figures 2 and, the movement of the gas through the system is shown by numbered arrows indicating the sequence of passage through the indicated portions of the unit. Figure 2 shows the flow in one direction and Figure 3 shows the flow in the reverse direction. It will be noted that, by the operation of the valves in the first and second distribution tubes, the direction of the arrow can be reversed simultaneously without requiring descent time. The ceramic honeycomb monolith can be replaced in the upper or lower compartment of the first and second thermal regenerative oxidizing units, easily by the removal of the end portion of the unit connecting the upper and lower compartments (which is conveniently suspended above). hinges, which are not shown) and then slide the monolith to replace it. Although thermal collector means have been shown as ceramic honeycombs, this is not necessary in any way. The monoliths can be replaced by modular units of individual thermal collector means or even by thermal waste collector means although this does not provide all of the advantages described above of easy maintenance. The thermal collector means are preferably ceramic but it is possible to use other suitable materials when the composition or the temperatures of the gases make this necessary. When the media are not monoliths they can have any convenient shape such as wheels, tubes, "bow ties", saddles, cylindrical pellets and spheres. The unit with upper * and lower compartments has been described only, but this is by no means a limitation on the scope of the invention since each thermal regenerative oxidizing unit may also comprise 3.4 to stacked compartments. Actually, however, stacked compartments are sufficient. The units of the invention can be used wherever the exhaust gases of a process comprise VOCs. Typical procedures in which the unit can be used include the removal of traces of organic solvents from the airflow surrounding various coating operations in which the coated material is contained in an organic solvent. Generately, it used to be applied to the recovery of both solvent and otherwise practicable by other means, since the thermal regenerative oxidizing units are designed primarily for the removal of relatively minor amounts of VOCs. The unit according to the invention is also particularly useful when the gases to be treated are contaminated with particulate matter. Any such particulate matter will usually be trapped in the heat exchange media and the pore diameters can be selected with this consideration in mind. Periodic cleaning of the media then also includes the removal of trapped particulate materials.

Claims (4)

NOVELTY OF THE INVENTION CLAIMS

1. - A horizontal thermal regenerative oxidizing unit comprising a combustion chamber connected to two heat regenerating units that house the thermal collector means, characterized furthermore because each unit comprises at least the first and second compartments in relation to see * ti warmly stacked with connection steps such that the gases passing through them pass through the hopper in a first direction through the first unit and subsequently subsequently in the reverse direction through the second unit.

2. A horizontal thermal regenerative oxidant unit according to claim 1, further characterized in that each heat regenerating unit comprises an upper and a lower compartment.

3. A horizontal thermal regenerative oxidant unit according to claim 1, further characterized in that each compartment of each heat regenerating unit comprises thermal collector means in the ceramic honeycomb monolith.

4. A horizontal thermal regenerative oxidant unit according to claim 1, characterized in that each compartment is provided with access means adapted to allow easy removal of the heat exchange means of the isma.