FI86579B - Elongate heat exchanger and fluid-treatment plant - Google Patents

Description

! 86579

This invention relates to a heat exchanger according to the preamble of claim 1 and a liquid treatment device according to the preamble of claim 4, which can be used in the wet oxidation of liquid waste water streams, including municipal waste, inside a downward borehole.

Above-ground wet oxidation systems have been in use for several years with limited success in treating municipal waste received from the sewage treatment process. Wet oxidation systems above ground use high surface pressure and heat to initiate the wet oxidation reaction, however, the device is not energy efficient, the system tends to fail and results in only partial oxidation of waste: see U.S. Patent No. 2,665,249 (Zimmermann) and U.S. Pat. Patent No. 2,932,613 (Huesler et al.). Wet oxidation processes on land have therefore not replaced traditional methods of municipal waste treatment, which include settling, dewatering, drying, incineration and the like.

Various downstream drill-25 hole fluid handling systems have been proposed in the prior art, but have been used only to a very limited extent. The fluid handling system in the downwardly directed borehole uses vertical pipes that generally extend downward into the ground from the control station. The liquid to be treated is pumped into the vertical reactor tubes and the hydrostatic pressure causes compression which aids in the desired liquid process or reaction. In the processes used heretofore, the reaction requires additional heat, which can be added by means of electric resistance coils or heated liquid-35 circulating in a heat exchanger. Air or other 2,86579 gases may be added to the liquid to be treated to aid in the reaction.

Although a number of prior patents propose a vertical well wet oxidation reaction system for treating municipal waste or other liquid waste streams, the methods and apparatus proposed in these patents have not been successful: see, e.g., U.S. Patent No. 3,449,247. As stated in these prior patents, the pressure generated by the pressure depends on the length of the reactor. Thus, it is theoretically possible to completely oxidize municipal waste at a depth of approximately 1600 m, provided that the concentration of oxidizable material in the municipal waste is balanced against the oxygen in the air injected into the system. However, a wet oxidation system for municipal waste in a downward borehole has so far not been fortunate to be built.

U.S. Patent No. 4,272,383 to Dr. McGrew, entitled "Method and Apparatus for Effecting Subsurface, Controlled, Accelerated Chemical Reactions," discloses the principles of the first successful downward borehole wet oxidation reaction system: for municipal waste. is currently in operation on a pilot basis in Longmont, Colorado. The device disclosed in McGrew's patent comprises a series of generally concentrically telescopically nested tubes, wherein the diluted municipal waste is preferably placed in an inner tube and flows down to the reaction zone near the bottom of the tube and recirculated back up through another tube surrounding the inner tube. - a tube, resulting in a reaction. Compressed air is injected into the downstream slurry, preferably in the form of Taylor-type gas bubbles. In McGrew's patent 35, the reaction temperature is controlled by a heat exchanger jacket 3 8 6 5 79 surrounding the inner concentric tubes, whereby heated oil or other heat exchange fluid is pumped into the jacket to control the temperature of the reaction zone.

The object of the present invention is to eliminate the problems described above. This object is achieved by a heat exchanger according to the invention, which is characterized by the features of the characterizing part of claim 1, and by a liquid handling device according to the invention, which is characterized by what is set forth in the characterizing part of claim 4.

The liquid treatment apparatus according to the invention preferably uses a centrally located heat exchanger, whereby the liquid to be treated is included in the recirculation pipes surrounding the heat exchanger, resulting in better control of the reaction zone temperature and more efficient heating of the liquid to be treated. The central downward heat exchanger tube is preferably an insulated tubular body comprising two concentric tubes telescopically nested in a spaced relationship, the space between the tubes being closed and preferably filled; inert gas. As will be appreciated, the tubes used in the fluid handling apparatus of the invention and the insulated tubular body comprise a series of tubes connected in a vertical array to accommodate the size. the length of the fluid handling device. Insulated tubular bodies have been used in the oil drilling industry and other industries for several years to transport heated liquids and gases. As discussed below, the liquid treatment apparatus of the present invention requires applying as much heat as possible to the reaction zone located adjacent to the bottom of the tubes. When heated-_ ···. The oil or other heat transfer fluid is placed on top of the unit or at ground level. Thus, radial heat losses through the insulated tubular body to the recirculated heat transfer fluid 4,86579 must be minimized. It has now been found that the substantial heat loss results from the passage of atomic hydrogen through the tubes between the tubular body of the insulated body, which hydrogen reunites to form gaseous hydrogen. Therefore, there is a need to develop an improved insulated tubular body that prevents the passage of hydrogen to improve the insulating properties of the insulated tubular body, resulting in an improved heat exchanger and liquid-handling device of the type described herein.

The heat exchanger according to the invention and the insulated tubular body are intended in particular, although not exclusively, for use in a liquid treatment plant for continuous treatment of liquid waste at elevated temperatures and pressures, such as a downhole treatment plant involving wet oxidation of municipal waste and other liquid waste. Preferably, the heat exchanger comprises an elongate insulated tubular body, preferably having an open end that is generally concentric with the second tube and telescopically nested therein, and preferably having a closed end for communication with the insulated tubular body near the open end of the surrounding tube. The insulated tubular body 25 includes a first inner tube and a second inner tube, which is preferably generally concentric with the first inner tube. with its pipe and surrounds it at a distance not in proportion. The space between the first and second tubes is preferably sealed and filled with an inert gas such as argon, helium or xenon. A heat transfer fluid such as oil is placed inside the first inner tube of the insulated tubular body at an elevated heat. ·· *. mode. The heat transfer fluid then flows through the insulated tube and returns through the annular space between the outer tube 35 of the insulated tubular body and the downstream tube containing the liquid and oxidizing gas for heating and recirculation.

The insulated tubular body of the heat exchanger comprises a hydrogen penetration barrier of the insulated tubular body 5 on the inner and outer surfaces of both tubes. The hydrogen penetration barrier is preferably formed by coating the inner and outer surfaces of the tubes with aluminum, nickel or copper. The through barrier reduces the flow of atomic hydrogen to the space between the first and second tubes of the insulated tubular body, thereby reducing heat loss from the heat transfer fluid in the center tube of the insulated tubular body to the returning heat transfer fluid in an annular region with an outer surface of the insulated tubular body. When the heat exchanger according to the invention is immersed in a liquid, the heat transfer is concentrated in a reaction zone located next to the end of the heat exchanger, which is particularly advantageous in the downstream borehole liquid treatment device according to the invention. The elongate heat exchanger is then surrounded by coiled tubing containing the liquid to be treated. The circulating tubes comprise a first tube which telescopically surrounds the outer tube of the heat exchanger in a spaced proportion and which receives the liquid to be treated which is in contact with the outlet tube 25 of the heat exchanger. The second tube, which is generally concentric with and surrounds the first tube, receives the liquid to be treated. The liquid to be treated, such as municipal waste or other liquid waste, is then placed between the outer tube of the heat exchanger and the first tube 30 of the liquid recirculation tubes. The liquid to be treated flows through the first pipe in contact with the heat exchanger and circulates again through the second outermost pipe. In this application. the liquid treatment device thus generates a liquid reaction zone adjacent to the end of the liquid circulating tubes.

"· 3 5 The liquid treatment device according to the invention is particularly suitable for the continuous treatment of municipal waste and liquid waste containing contaminated liquid waste at elevated temperatures and pressures. generally concentric and telescopically nested tubes extending vertically into the ground to a depth of up to 1600 m or deeper.The central insulated tubular body receiving the hot heat transfer fluid preferably has an open end, and the outer tube of the heat exchanger preferably has a closed end. next to the open end of the tubular body, in which way a connection is made with the insulated tubular body 15 and a continuous flow of heat exchange fluid. the tube surrounding the outer tube of the heat exchanger also has an open end, and the outermost tube may also have a closed end which communicates with the open end of the liquid circulating tubes, thus forming a continuous circulation of the liquid to be treated. The heated reaction zone is thus located adjacent to the bottom of the liquid recirculation tubes, and the compression of hydrostatic pressure in the circulating tubes ensures a liquid reaction of the liquid waste at elevated temperatures and pressures in the reaction zone.

* In a preferred embodiment of the heat exchanger and liquid treatment device according to the invention, the hydrogen diffusion barrier is an aluminum diffusion coating on the inner and outer surfaces of the concentric tubes of the insulated tubular body, forming an iron-aluminum coating on the surface of the iron-aluminum alloy. particularly effective in preventing the diffusion of atomic hydrogen into the enclosed space between the tubes, the diffusion barrier may also be formed by electroplating copper or preferably nickel on the surfaces of the tubes.As described, the diffusion of atomic hydrogen into the enclosed space of an insulated tubular body increased thermal conductivity, resulting in increased heat losses from the heat exchanger fluid flowing through the insulated tubular body, to the recirculating heat transfer fluid in the second outer tube of the heat exchanger.

Other advantages and features of the present invention will be more fully understood from the following description of the preferred embodiments, the appended claims, and the drawings, which are briefly described below.

Figure 1 is a schematic illustration of a preferred embodiment of a continuous fluid handling device according to the invention; and Fig. 2 is a cross-sectional view of the lower part of the liquid handling apparatus shown in Fig. 1.

The continuous liquid treatment device 20 described in the drawings is a liquid reaction device located in a vertical hole suitable for treating various contaminated liquid wastes, which treatment includes the wet oxidation treatment of municipal waste. As proposed in the McGrew patent referenced above, the fluid handling device comprises a plurality of generally concentric and telescopically nested tubes extending vertically into the ground. In the municipal waste wet treatment plant I ”, for example, the pipes can extend approximately 1600 m into the ground, creating a very substantial hydrostatic pressure. It will be appreciated, however, that the length of the tubes 30 depends on the liquid to be treated and the desired liquid reaction. The treatment device according to the invention can also be used in various conversion reactions, in which case solid particles are suspended in the circuit. In addition, * · ’pipes are usually not continuous. Each pipe comprises 35 several sections connected in series in a straight line as a pipeline in the same way as pipes in an oil drilling hole. In a typical wet waste application for municipal waste, each pipe section has a length of 12.2 m, a total length of about 1586 m and a flow rate of the liquid to be treated of about 360 to 1800 liters per minute.

In a preferred embodiment of the liquid treatment device according to the invention, the liquid heat exchanger 22 is located in the center of the concentric tubes of the liquid treatment device. The first or innermost tube of the heat exchanger is an insulated 10 tubular body 24 with an open end 26. As described more fully below, the insulated tubular body reduces radial heat transfer from the flowing heated heat transfer fluid in the insulated tubular body in the second tube 28 to the recirculating upstream heat. a. As shown, the first tube or insulated tubular body 24 is generally concentric with the second tube 28 and telescopically nested therein, and the second tube has a closed end 30 adjacent the open end 26 of the insulated tubular body 20. The liquid to be treated is then circulated around the heat exchanger 22, as now described.

The third tube 32, which is the first tube of the outer fluid circulation line, surrounds the heat exchanger 22 25 in a generally concentric, spaced telescopic relationship. The third tube 32 has an open end 34 adjacent the closed end 30 of the liquid heat exchanger. The fourth tube 36 surrounds the third tube 32 in a substantially concentric distance in a telescopic relationship and comprises a closed end 38 adjacent the open end 34 of the third tube 32. The liquid to be treated is circulated downwardly through tube 32 in contact with the second tube 28 of the heat exchanger 22, and the treated liquid then flows through the open opening 34 of the third tube 32 and upwardly through the fourth tube 38 in contact with the outer surface of the third tube 32. As described in the previously referenced McGrew patent, the liquid treatment device creates a reaction zone adjacent to the bottom of the device, whereby the liquid to be treated reacts under heat and pressure. The main object of the present invention is to concentrate the heat transferred from the heat exchanger in the liquid circulating in the tube 32 in the lower reaction zone and to reduce the radial heat transfer, especially in the upper part of the heat exchanger device.

Figure 1 schematically shows the above ground components used in a liquid handling apparatus and process. A heat transfer fluid such as oil is stored in a storage tank 40. The oil is heated in a heater 42 as in a conventional gas-fired heater. The oil is pumped by pump 44 from storage 40 via line 46 to heater 42, and the flow rate is controlled by valve 52. The heated oil is then passed through line 48, and the flow rate is controlled by valve 50. Where the liquid reaction is exothermic 20 as in a wet oxidation reaction, cooling of the reaction zone may be required. When the heat of reaction exceeds the preferred temperature in the reaction zone. The · *: device thus shown includes a heat exchanger in which the oil can be cooled. The oil from storage 40 can be pumped through line 25 56 to heat exchanger 54 by pump 57. The flow is controlled by line 62. The colder oil is then discharged through line ... 58 and valve 60 to the liquid treatment device supply line 48.

Normally heated oil is fed through line 48 * 30 to the top of the insulated tubular body 24. As V is best shown in Figure 2, the heated oil then flows downward through the insulated tubular body, as shown by arrow 70. The oil then flows out of the open end 26 of the insulated tubular body, and the oil * 35 is recirculated upwardly through line 28 in contact with the tubular body. with the body, as shown by arrow 72. the oil or other heat transfer fluid is then removed from the top of the tube 28 via line 74 back to storage 40 via valve 76.

The liquid to be treated, such as contaminated industrial liquids, municipal waste or the like, is fed to the top of the pipe 32 and circulates around the heat exchanger 22 as described. As shown in Figure 1, the liquid to be treated is stored in a storage tank 80. As described in the McGrew patent referenced above, the liquid treatment device is particularly suitable for treating municipal waste from a conventional municipal wastewater treatment plant. The waste is received via line 82, and the flow is controlled via line 84. Liquid waste 15 is then delivered to the device via line 86 and valve 88. The liquid waste is preferably diluted with the liquid coming out of the municipal wastewater treatment plant delivered via line 90 and valve 95. The liquid waste is preferably diluted to control the proportion of oxidizing material delivered to the fluid-20 tea processor. The diluted liquid slurry, liquid waste or other liquid to be treated then flows downwards through the pipe 32 ... in contact with the outer wall of the heat exchanger 22, as shown by arrows 94. As described, the pipe 25 32 has an open end 34, and the treated liquid then flows up-to-j through the outer tube 36 from the fluid handling device. for removal. As shown in Fig. 1, the hand tel. The liquid is discharged from the pipe 36 via a line 98 to the tank 100. When the device is used for liquid waste wet. . 30 for oxidation, the tank 100 is preferably a settling tank,; ‘· Where the substantially inert ash is separated from the water. The ash can be taken in via line 102, and the flow rate is controlled by valve 104.

· * '; In the wet oxidation reactor, the material on the surface can ·. 35 can be removed via line 106 and used as a dilution of 8 6 579 na in the process. As shown in Figure 1, surface material is removed through line 106 and delivered to line 86 which communicates with tube 32. The flow and dilution rates are controlled by valve 108.

As described in the McGrew patent referenced above, air is injected into the downstream slurry in the wet oxidation of municipal waste or other waste materials. Air is preferably injected into the downstream flow of the liquid to be treated below ground level 39 in the form of Taylor-type bubbles. It will be appreciated that other liquid reactions may require other gases depending on the desired reaction. Therefore, the proposed device comprises an air compressor 110, and compressed air is supplied downstream of the liquid to be treated in line 32 below ground level by line 112, and the flow is controlled by valve 114. 110 may also be a pump supplying the reaction gas present in the liquid treatment device of the invention.

As described, the liquid treatment apparatus of the invention is primarily intended for treating liquid waste at elevated temperatures and pressures. The pressure is formed by liquid pressure and the temperature is formed by the heat of the reaction when the reaction is exothermic and by a heat exchanger 22. In a typical wet oxidation reaction of municipal waste, the bottom hole temperature is about 260 ° C. Thus, the second or outer heat exchanger

; the oil supplied to the tube 28 of the engine would be above 260 ° C

temperature. In a typical oxidation reaction, the oil is supplied to the inlet of the insulated tubular body 24. . 30 at a temperature of about 370 ° C. The oil or other heat transfer fluid then flows downward to the open end 26 of the insulated tubular body, where it is supplied to the outer tube 28 of the heat exchanger at about 275-290 ° C. The liquid then flows upwardly through the tube 28, as shown by arrow 72 in Figure 2, and heats the downwardly flowing hand-held liquid which contacts the outer surface of the tube 28 in the tube 32. The oil temperature at the upper outlet of the tube 28 is about 65 ° C. . As described, the liquid reaction takes place in a reaction zone where the temperature of the liquid flowing down exceeds 177 ° C. Therefore, in a preferred embodiment of the fluid handling device, an insulated tubular body 24 is used to reduce radial heat transfer from the downwardly flowing heat transfer fluid in the insulated tubular body 24 to the colder heat transfer fluid in line 28. Details of the insulated tubular body 24 are shown in Figure 2. having an outer surface 122 and an inner surface 124, and the outer tube 126 having an outer surface 128 and an inner surface 130. The inner tube 120 is preferably concentric with the outer tube 126 and telescopically nested in this spaced relationship. The space 132 between the tubes is secured and closed by a sealing ring 134, which may be welded or otherwise secured to the space 20 between the tubes. The space between the tubes is then evacuated and filled with an inert gas such as argon, helium and xenon. The inert gas has a low thermal conductivity, which reduces the radial heat transfer through the spaces 132 between the tubes: 120 and 126.

: ·: 25 The heat transfer across the space between the pipes 132 is defined by the following equation: Q = kA At / Ar. . 30 where Q is the heat transferred in units Btu / hour, k is the thermal conductivity, A is the heat transfer area t / r is the radial temperature gradient. In Longmont, Colorado *; · In an experimental wet oxidizer, the inner tube 120 has an inner diameter of 50.8 mm and an outer diameter of 60.9 35 mm. The outer tube 126 has an inner diameter of 76.2 mm and an outer diameter of 86,579 88.9 mm. Thus, Aron 15.9 mm. In the above example, At at the top of the heat exchanger is 305 ° C (371-66 ° C). Thus, the temperature gradient is substantial and substantial radial heat transfer occurs at the top of the fluid handling device despite the fact that the inner tube 24 is well insulated.

The use of an insulated tubular body 24 results in a substantial reduction in radial heat loss, however, the specific properties have decreased over time. It has now been found that the reduction in specific properties in an insulated tubular body is due, at least in part, to the passage of atomic hydrogen through the insulated tubular body into the interpipe space 132. Atomic hydrogen is capable of penetrating gaps in metal tubes 120 and 15126. which cannot go through the walls. Hydrogen gas then accumulates in the space 132 between the tubes, increasing the thermal conductivity of the gas. As described above, the space between the walls is filled with 20 inert gases. The insulated tubular body of the invention therefore includes a hydrogen passageway that reduces the flow of atomic hydrogen into the space between the tubes.

The preferred hydrogen penetration barrier comprises: a diffusion coating of aluminum on the inner and outer surfaces 124, 126, 128 and 130 of both tubes. The tubes are preferably formed of steel so that the diffusion coating is an iron-aluminum alloy. Aluminum diffusion coatings are commonly used in steel furnace tubes and the like. 30 to improve corrosion resistance and increase furnace life by a method known as "Alonizing". In the Aloni-zing process, the tube is sealed on the outside and contains aluminum and alumina powder and placed in a new manner at about 930 ° C for three to four days. Coating '. 35 is very hard and does not interfere with welding. It has now been found that a diffusion coating made with an Alonizing granular telescope substantially reduces atomic hydrogen diffusion.

i4 8 6 5 79

The hydrogen diffusion barrier coating can also be formed by galvanizing nickel on the inner and outer surfaces of the pipes. Galvanized nickel also forms an excellent atomic hydrogen diffusion barrier, not quite as good as surfaces made by the Alo-nizing method. Finally, the hydrogen diffusion barrier can be formed by electroplating copper on the surfaces of the tubes, however, copper interferes with welding and can adversely affect the strength properties of the tubes. When the surface is galvanized with nickel or copper, the thickness of the coating should be about 0.001 mm. When comparing pure steel to an insulated tube 15 coated with a hydrogen penetration barrier, the coated insulated tube has a reduced degree of hydrogen permeability by a factor of the order of 1000. When comparing Alonizing steel to nickel-plated steel, the throughput was reduced by a factor of the order of 10. Thus, the most popular applications comprise a hydrogen diffusion barrier formed by diffusion-coated aluminum, thereby forming an iron-aluminum alloy. The hydrogen diffusion barrier substantially reduces the deterioration of the insulating properties of the insulated tubular body.

The method of forming an insulated tubular body thus comprises forming substantially nested telescoping steel tubes, preferably V: seamless tubes, as shown at 120 and 126 in Figure 2. A hydrogen penetration barrier coating is then formed on the tubes, preferably the outer tubes of both tubes. 'for interior surfaces. The tubes are then assembled into a nested concentric telescopically spaced relationship, as shown in Figure 2, the space between the tubes is sealed with a sealing ring 134. The space 35 is then evacuated and the space is filled with an inert gas 86579 melt such as neon, argon or xenon. . The resulting insulated tubular body is not prone to deterioration of the insulation because the barrier reduces the permeation of atomic hydrogen, as described.

While describing a preferred embodiment of a heat exchanger according to the invention and a continuous liquid treatment device, it is to be understood that various modifications may be made to the invention disclosed herein within the scope of the appended claims. As described, the heat exchanger and liquid treatment device of the invention can be used for a variety of applications, however, the invention is particularly intended for use in a vertical tube or deep well reaction device, such as for the wet oxidation of municipal waste. However, the device can be used to treat various types of contaminated or wastewater or contaminated solid waste suspended in a liquid. The device can also be used to process or modify various materials in a liquid reaction that requires elevated temperatures and pressures.

Claims (8)

An elongate heat exchanger comprising an elongate insulated tubular body (24) having an open end (26) and substantially concentrically telescopically disposed within and surrounded by a second tube (28), wherein the second (28) tube is enclosed an end (30) near and in connection with the open end of the insulated tube body (24), the insulated tube body (24) having a first inner metal tube (120) and a second outer metal tube (126) substantially concentric with and surrounding the first tube (120); in a spaced relationship, the space (132) between the first and second tubes (120,126) being closed and filled with inert gas; a hot heat transfer fluid received at one end of the insulated tube body (24) and flowing through the tube body, the heat transfer fluid cooling and returning through the second tube (28) for heating and recirculation 20, characterized in that the heat exchanger has a hydrogen passage barrier to the insulated tube body ( 24) the inner and outer surfaces of the first and second tubes (120,126) '... (124,126,128,130), wherein the hydrogen passageway comprises a metal coating selected from the group consisting of aluminum, nickel and copper, wherein the throughput * · The barrier reduces the flow of atomic hydrogen into the space between the first and second tubes (24, 28) of the insulated tube body, thus reducing heat losses from the heat transfer fluid in the insulated tube body (24). . In a return pipe (28) to the returning heat transfer fluid. Heat exchanger according to claim 1, characterized in that the first and second tubes (120, 126) of the insulated pipe body (24) are made of steel and the hydrogen penetration barrier consists of a diffusion coating of aluminum on the inner and outer surfaces (124, 126 , i7 86579 128,130) and forms an iron-aluminum alloy. Heat exchanger according to claim 1, characterized in that the hydrogen penetration barrier comprises a galvanized coating selected from the group consisting of nickel and copper. A liquid treatment apparatus for the continuous chemical reaction of liquid waste with a second reactant at elevated temperatures and pressures, the liquid treatment apparatus comprising a plurality of telescopically nested tubes (24, 28, 32, 36) extending vertically into the ground, the tubes comprising a first inner tube ( 24) having an open lower end (26) and forming an insulated tube body, the insulated tube body (24) comprising substantially concentric telescopically nested spaced apart tubes (120,126) with the space (s) (132) between the tubes closed and filled with insulating medium; a second tube (28) surrounding the insulated tube piece (24) forming the first tube in a spaced 20 relationship and having a closed lower end (30) in communication with the lower end of the first tube; a third tube (32) surrounding the second tube (28) in a spaced relationship and having an open lower end (34); and a fourth tube (36) surrounding the third tube (32): ': 25 spaced apart and having a closed *: · lower end (38) and communicating with the third tube spaced apart; a hot heat transfer fluid received in the insulated pipe body (24) formed by the first pipe and flowing downwardly through the first pipe (24) and upwardly between the first and second pipes (24,28) in heat transfer relationship with the liquid waste, the second reactant flowing downwardly to the second and in the annular space between the third tube (28, 32) reacts with the liquid waste and the second. To initiate a chemical reaction between the present material in the reaction zone located near the lower end (34) of the third tube (32), the insulated tube body (24) reducing the hot heat transfer fluid in the insulated tube body (24) forming the first tube and the upstream heat transfer fluid. above the heat transfer zone, and the liquid waste recirculates upward in the annular space between the third and fourth tubes (32,36) to be removed from the device, the tubes being long enough to generate a liquid pressure sufficient to maintain the liquid waste and the second reactant reaction temperature, characterized in that the insulated pipe piece (24) has a hydrogen passage barrier to reduce the hydrogen accumulating in the space 15 between the pipes of the pipe piece, which reduces heat loss in the first from the heat transfer fluid flowing downward in the tube (24) to the recirculating heat transfer fluid in the annular space between the first and second tubes (24, 28) and maintains the reaction zone 20 at the bottom of the third tube (32). A continuous operation according to claim 4. : liquid treatment device, characterized in that the hydrogen: 25 barrier comprises a coating on the insulated pipe section (24) with pipes (120, 126). Continuous fluid handling device according to Claim 5, characterized in that the pipes (120, 126) of the pipe body (24) are made of steel and have a cover. . 30 te is selected from the group consisting of aluminum, Nikke and copper. ‘7. A continuous operation according to claim 4; liquid treatment device, characterized in that the pipes (120, 126) of the insulated pipe body (24) are made of steel and the hydrogen permeation barrier consists of a diffusion coating of aluminum on the inner and outer surfaces of the pipes, whereby an iron-aluminum alloy is formed. A continuous liquid treatment device according to claim 5, characterized in that the coating comprises a galvanized coating selected from the group consisting of nickel and copper. 20 86579