JPS5933827B2 - heat and mass transfer equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to physicochemical processing equipment, and more particularly to heat and mass transfer equipment.

The heat and mass transfer device according to the invention can be used as a heat exchanger for heating liquid and gaseous media or as a cooling device for such media.

In addition, when equipped with a palladium alloy tube, this device has a diffusion effect and can be used for high purity purification of hydrogen and separation of hydrogen from a gas-liquid mixture.

When equipped with membrane catalysts or other catalysts, for example tubes made of alumina-based metal, the device acts as a catalyst chamber.

A heat/mass transfer device comprising a housing within which foil strips or sheets are arranged to divide the device into a plurality of chambers into which substances are pumped to carry out the heat/mass transfer process. Mass transfer devices are known (Soviet inventor certificate No. 361)
, 805 and U.S. Pat. No. 3,782,077).

This equipment cannot be used to carry out liquid phase hydrogenation.

This is because the foil pieces cannot withstand the high differential pressure between the chambers.

Reinforcing the foil pieces with mesh inserts has other undesirable consequences.

That is, the material to be treated decomposes or converts, producing by-products on the surface of the insert.

Also known in the art are heat/mass transfer devices that include a housing with a plurality of tubes disposed therein and are used as diffusion devices (U.S. Pat. No. 2,911,05
No. 7 and No. 3,392,510).

By using these tubes, it is possible to carry out treatments with high differential pressures between the inner and outer spaces of the tube.

However, the arrangement of the tubes in the housing of the device does not allow for proper exposure of the tube surfaces to the material flow involved in the process, resulting in loss of material in the catalytic process or overheating in the stagnation area. occurs.

Catalyst chambers with palladium alloy membrane catalysts are known in this technical field (USSR Inventor Certificate No. 292, 36
(See No. 1).

The tube has a cylindrical housing containing a U-shaped tube of membrane catalyst.

The inlet and outlet ends of these tubes are affixed to the tubesheet of a header having a partition plate and providing a flow of reactants through the interior of the tubes.

The bottom of the catalyst chamber housing is provided with pipes for introducing the other reactants, whereas the side walls of the housing are provided with pipes for discharging the reaction products.

When substances are fed into the housing from below, these substances come into contact with the U-shaped catalyst tube and react on the surface of this catalyst tube,
The reaction products then exit the housing and flow into the side tube.

However, this device has a retention area in the upper part of the housing.

The material flow slows down in this area and heats up during exothermic reactions.

Furthermore, when the material flow slows down or stops, excessive catalytic steps occur, resulting in the formation of by-products or decomposition and gumming of organic materials.

The present invention provides a heat/mass transfer device in which a housing and tubes housed therein improve hydrogen separation, e.g. in a diffusion device, and increase the yield of the desired product, e.g. in a catalytic process, and reduce retention zones. It is an object of the present invention to provide an apparatus constructed and arranged to remove.

The present invention provides a heat/mass transfer device having a housing in which a plurality of tubes are disposed, the inner and outer ends of these tubes being mounted inside a header, wherein the upper and lower portions of the housing are elongated. a hollow, centralized branch tube, the base of which branch tube joins the housing, and said tubes are assembled into a tube bank, the headers of these tubes being disposed within the single branch tube; The purpose of the present invention is to provide a device that allows for

The construction of the device eliminates stagnation areas, produces a uniform velocity distribution of reactant streams over the entire cross-sectional area of the device, and also produces uniform exposure of the outer tube surfaces to the substances participating in the heat/mass transfer process.

The branch pipes may be curved to produce a uniform flow velocity distribution, and a conical header may be housed inside the branch pipes.

The branch pipe can also have a conical shape.

In that case, the manufacturing process is simplified, but a uniform distribution of flow rates is also obtained.

The device can also include at least one other group of tubes arranged in the same housing.

The inlet and outlet ends of the tubes of this tube group are collected in their headers, which are placed alternately in the upper and lower branch tubes.

This structure makes it possible to maintain a uniform flow rate distribution and proper exposure of the tube to the reactant flow.

The device housing and the tube bank are formed in the form of a right angled column, and the tube groups are arranged with respect to each other such that the exit holes of the tubes are staggered.

This allows the tube to be placed exactly in the device,
This makes it possible to increase the active area of the tube per unit volume of the housing and thus to increase the workload of the device.

The housing and tube bank can be cylindrical to simplify their manufacture.

Also, the inlet and outlet ends of the tubes in the tube bank can be mounted in a single conical header.

This creates a uniform distribution of the reactant flow inside the tube and eliminates stagnation areas.

The tubes of the tube bank can be wrapped around each other in a helical manner.

This eliminates the vibration of the tubes due to the high-speed reactant flow toward the tube group, making it possible to improve the operational reliability of the entire device.

The tubes in the tube group are formed in a spiral shape, and the lowest spiral tube changes into a straight section passing through the inside of the spiral toward the tube group header, and the ratio of the tube outer diameter to the helical pitch is set to 0.2~ 1.0, and the same effect can be obtained if the tubes are arranged in a tube bank such that each spiral tube fits into the space between adjacent spiral tubes.

This allows the outer surfaces of the tubes within the tube bank to be completely exposed to the reactant flow.

As for the ratio between the tube outer diameter and the helical pitch, this is selected taking into account the following points:

If this ratio exceeds 1.0, the spirals cannot enter into adjacent interspiral spaces.

If this ratio is less than 0.2, the screws fit too loosely between adjacent screws, resulting in undesirable vibration of the tubes during operation of the device.

In addition, the containers in the tube group have a flat spiral shape and are arranged in contact with each other, and the inlet and outlet ends of the containers are connected to a tubular header arranged perpendicularly to the plane of the flat gauge line. It can also be installed inside.

This structure allows the volume of the device to be filled to the maximum extent with the tubes, thereby increasing the workload of the device and simplifying the header structure.

The tubes can be formed into a double flattened helix and placed next to each other such that each successive helix is a mirror image of the preceding helix.

This simplifies the tube assembly technique and allows the tube to fill the device volume to the maximum extent possible.

The tube can take the shape of an Archimedean spiral.

This can reduce the number of weld seams between the tube and the header, thereby increasing the operational reliability of the device.

The tube can be made of a material that has catalytic properties.

This allows the use of this heat/
It becomes possible to use mass transfer equipment.

For example, if a tube with a surface catalyst layer of nickel or palladium is used, a hydrogenation or dehydrogenation step can be carried out in this device, in which case the cooling or heating of the device is carried out using a heat transfer medium inside the tube. This can be carried out by sending .

In addition, a tube can be made with a decatalyst that selectively permeates hydrogen.

This is suitable for devices that carry out one or two catalytic steps and use the heat released in one step to carry out an endothermic step.

In devices of this type, it is also possible to carry out decomposition or catalytic conversion of the feed material in order to obtain high-purity hydrogen.

The tubes can also be made from hydrogen-permeable palladium alloys.

In this way, the heat/mass transfer device of the present invention can be used as a diffusion device for producing high-purity hydrogen, for enriching gaseous or liquid products with hydrogen, or for purifying and removing various substances from hydrogen. becomes possible.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

The heat and mass transfer device according to the invention has a housing 1 which is provided with a central branch pipe 2, the main part of which has the shape of the central part 3 of the housing 1.

The device also has a tube bank 4 of tubes 5, the ends of which are collected in a header 6.

The branch pipe 2 has the shape of a square as shown in FIG.
It forms a cone shape as shown in the figure.

The tube group 4 can form a right-angled vertical column, in which case the header 6
has a conical shape and comprises a partition plate 7 and a tube sheet 8, into which the tube 5 is mounted as shown in FIGS. 3 and 4.

In this case, the device 71 Uging 1 also forms a right-angled column shape,
The tube groups 4 are arranged in opposite directions in the housing 1, and headers 6 are provided in the upper and lower branch tubes 2, respectively, as shown in FIGS. 1 and 5.

When the tubes 5 are wound around each other helically, the tube group 4 has a cylindrical shape and the ends of the tubes are fixed in the header (FIGS. 6 and 7).

6 If the tubes 5 form a helix 9 (FIG. 9), the tube ends are fixed in the tube sheet 8 of a conical header 10 with an inlet tube 11.

In this construction, the inlet end 12 of the tube 5 is collected by the inlet tube 11, while the outlet end 13 of the tube is collected by the conical header 10.

In this case, the tube group 4 has a cylindrical shape (Figs. 8, 9,
10 and 11).

The pitch of the helix 9 is determined so that the spacing 14 between the helices is equal to or slightly larger than the diameter of the tube 5, and the ratio of the outer diameter of the tube to the helix pitch is 0.2 to 1.0.

This makes it possible to arrange the tubes 5 inside the tube group 4 without waste, since the helix 15 of the helix 9 fits into the adjacent helix space 14 (FIGS. 10 and 12). .

When the tube group 4 is cylindrical, the housing 1 is also cylindrical,
These tube groups 4 are arranged in mutually opposite directions inside the inserting ring 1, for example, in a hexagonal shape (see FIGS. 1 and 13).
figure).

The tubes 5 are formed into a double flattened helix 16 (FIG. 14), and these spirals are rotated 180° so that the succeeding spiral 17 forms a mirror image of the preceding spiral, and are placed in contact with each other one above the other, thereby forming the tube group 4. It can be assembled as

In this case, the inlet and outlet ends of the tube 5 are attached to a tubular header 18 (first
5 and 16).

The location of the outlet and inlet ends of tube 5 is determined by the number and location of headers 18.

That is, these headers can be placed at angles of 180°, 90° and 60° (Figs. 18 and 20);
Figures 19 and 21 respectively show the structure of the tube group and -.
The assembled state of the tube 5 to the ladder 18 is shown.

The tube 5 can also have the shape of a double Archimedean spiral 19, which consists of two spirals arranged one above the other (second
2 and 23).

To assemble these tubes 5 into tube group 4, two headers 18 are used.
is sufficient (Figure 24).

The tube group of tubes 5 wound in a flat spiral shape and an Archimedean spiral shape has a cylindrical shape as a whole, and this tube group can be inserted into the housing 1 alone (FIG. 2) or in combination (FIG. 13). Deploy.

In order to fully utilize the interior of the device, the tubes 5 of the tube bank 4 can be arranged in the central part 3 of the housing 1 and in the branch tube 2 (FIG. 25).

The heat and mass transfer device of the present invention operates as follows.

Depending on the heat/mass transfer process carried out in the apparatus, the tubes 5 may consist of the structural material of the apparatus to act as a heat exchanger or as a catalytic chamber for carrying out one or several catalytic processes. or a hydrogen permeable palladium alloy to act as a mass transfer diffusion chamber for the purification and separation of hydrogen.

When the device is used for heat exchange, a heat transfer medium is supplied into the housing 1 from the branch pipe 2.

The substance to be heated passes through the header 6 of the tube group 4 to 6 tubes 5.
is sent into the

When the heat transfer medium flows down inside the housing, the tube 5
heat is transferred to the substance to be heated through the walls of the

The used heat transfer medium is discharged from the device through the lower branch pipe 2, while the heated material is discharged through the header 6 of the tube bank 4.

It is also possible to introduce the heat transfer substance into the interior of the tube 5 and also the substance to be heated into the device housing.

If the tube consists of a catalyst or is coated with a catalyst, the reactants are fed into the housing 1 through a single branch tube.

When the reactant stream contacts the surface of tube 5, the reactants are converted.

The reaction product is discharged from the other branch pipe 2.

A heat transfer medium is pumped through the header of the tube bank 4 to heat and cool the device.

In order for the device to operate as a heat/mass transfer device, tubes made of membrane catalyst are used.

For example, the material to be dehydrogenated is conveyed into the housing 1 through the upper branch pipe 2.

Other substances to be hydrogenated are also introduced through the header of tube bank 4.

During the dehydrogenation reaction, hydrogen is generated on the outer surface of the membrane catalyst tube.

This hydrogen diffuses into the tube 5 and onto the inner surface of the tube, causing a hydrogenation reaction with the substances inside the tube.

The dehydrogenation reaction product is discharged through the lower branch pipe 2, whereas the hydrogenation reaction product is discharged through the header of the tube bank 4.

It is also possible to introduce the substance to be dehydrogenated into the interior of the tube 5 and the substance to be hydrogenated into the housing.

In the case of a device acting as a mass transfer device, for example a device producing high purity hydrogen, the tube 5 consists of a palladium alloy (so% palladium, 20% silver).

A hydrogen-containing mixture (for example water gas) is fed into the housing 1 from the upper branch pipe 2 and the hydrogen passing through the walls of the pipes 5 is discharged through the header of the pipe bank 4.

The mixture from which hydrogen has been removed is discharged through the lower branch pipe 2.

In the case of the heat/mass transfer device according to the invention, the shape of the tube 5 has various embodiments.

All of these embodiments ensure efficient exposure of the tube wall to the fluid, enhanced heat removal efficiency in exothermic reactions, and improved contact between the tube surface and the reactants, thereby increasing the target product. The yield as well as the working capacity of the equipment is significantly increased.

Since the tubes 5 are assembled as a tube group 4, it is easy to replace the tubes in the event of a failure.

The use of flat helical and Archimedean helical tubes 5 makes it possible to use tubes as long as 4 m or more, which reduces the number of welded seams and simplifies assembly techniques, resulting in operational reliability. degree is increased.

Furthermore, these embodiments increase the ratio of tube surface area to device volume, increasing the amount of work per device volume by a factor of 1.5 to 2.

[Brief explanation of the drawing]

1 is a vertical sectional view of a heat and mass transfer device with a horn-shaped branch pipe according to the invention; FIG. 2 is a partially cutaway side view of a device with a conical branch pipe according to another embodiment of the invention; Third
The figure is a vertical sectional view of the U-shaped tube group, and Figure 4 is IV-I in Figure 3.
V cross-sectional view, FIG. 5 is a cross-sectional view taken from ■-■ in FIG. A cross-sectional view, FIG. 8 is a side view showing the inside of a device having a group of spiral tubes, FIG. 9 is a view showing the spiral shape of the tubes in FIG. 10, and FIG. 11 is a vertical sectional view of FIG. 10, and FIG.
The figure is a layout diagram of a single helical tube taken in the horizontal plane of the tube group in FIG. 10, FIG. 13 is a longitudinal cross-sectional view of a device having a plurality of cylindrical tube groups, and FIG. 14 is a plan view of a double flat helical tube. Figure 15 is a side view of the tube group in Figure 14, Figure 16 is a plan view of the tube group in Figure 15, and Figure 17 is an X-X cross section of the tube group in Figure 15. 18 is a plan view of another embodiment of the double flat helical tube, FIG. 19 is a plan view of a group of tubes of FIG. 18, and FIG. 20 is a plan view of another embodiment of the double flat helical tube. 21 is a plan view of the tube group of the tubes in FIG. 20, FIG. 22 is a plan view of the double Archimedean tube, and FIG. 23 is the xxm-xxm diagram in FIG.
24 is a side view of the group of tubes of FIG. 22, and FIG. 25 is a longitudinal sectional view of another embodiment of the device of the invention. 1...Housing, 2...Branch pipe, 4
...Pipe group, 5 ...Pipe, 6 y 10
t 18...Header, 11...Introduction tube, 16...Flat spiral tube, 19...Archimedean spiral tube.

Claims (1)

[Scope of Claims] 1. A heat and mass transfer device having a housing, in which a plurality of tubes are arranged, and the inlet and outlet ends of these tubes are respectively installed in a header, /＼ Elongated, hollow, centralized branch pipes 2 are provided at the upper and lower parts of the housing 1, the bottoms of these branch pipes are joined to the housing 1, and the pipes 5 are assembled to form the pipe group 4, and the header 6 is assembled. A heat and mass transfer device characterized in that it is disposed in one of the branch pipes 2. 2. The heat and mass transfer device according to claim 1, characterized in that the branch pipe 2 is in the shape of a horn. 3. Heat and mass transfer device according to claim 1, characterized in that the branch pipe 2 has a conical shape. 4 At least one further tube group 4 in the same housing 1
The inlet and outlet ends of the tubes 5 of this tube group 4 are also installed in their headers 6, and these headers 6 are installed alternately in the upper and lower branch tubes 2. A heat and mass transfer device according to any one of claims 1 to 3. 5. The apparatus housing 1 and the tube group 4 form a right-angled vertical column, and the tube groups 4 are arranged relative to each other so that the outlets of the tubes 5 are staggered. 4
Heat and mass transfer equipment by term. 6. Heat and mass transfer device according to claim 1, characterized in that the device housing 1 and the tube bank 4 have a cylindrical shape. 7. Heat and mass transfer device according to claim 1, characterized in that the inlet and outlet ends of the tubes 5 in the tube bank 4 are mounted in a conical header 6. 8. Heat and mass transfer device according to claim 1, characterized in that the tubes 5 of the tube group 4 are wound around each other in a helical manner. 9 The container tube 5 of the tube group 4 has a spiral shape 9, and the coil portion at the lowest position transitions to a straight portion passing through the inside of the spiral toward the header 10 of the tube group 4, and the outer diameter of the tube 5 and the helical pitch are The ratio is in the range 0.2 to 1.0, and the tubes 5 are characterized in that they are assembled into the tube group 4 in such a way that each coil section fits into the space of an adjacent coil section. A heat and mass transfer device according to any of claims 1-4, 6 or 7. 10 The container tube 5 in the tube group 4 has a flat helical shape 16,
Claim 1, characterized in that the inlet and outlet ends of these tubes (5), which are arranged next to each other, are installed in a tubular header which is arranged perpendicularly to the plane of the oblate spiral. A heat and mass transfer device according to any of clauses 4 to 6. 11. Claims 1 to 4, characterized in that the tube 5 has the shape of a double oblate helix 16, which are arranged in mutual connection such that each subsequent helix forms a mirror image of the preceding helix. section,
Heat and mass transfer device according to either clause 6 or 10. 12. Heat and mass transfer device according to any one of claims 1 to 4, 6 or 10, characterized in that the tube 5 has the shape of an Archimedean spiral 19. 13. Heat and mass transfer device according to any one of claims 1 to 12, characterized in that the tubes 5 consist of a material with catalytic properties. 14. Heat and mass transfer device according to any one of claims 1 to 13, characterized in that the tubes 5 consist of a membrane catalyst selectively permeable to hydrogen. 15. Heat and mass transfer device according to any one of claims 1 to 14, characterized in that the tube (5) is made of a palladium alloy that is permeable to hydrogen.