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CA2073573A1 - Temperature variable nest of heat exchanger tubes for constant quantitative ratios of the exchange gases and a heat exchange process - Google Patents

Temperature variable nest of heat exchanger tubes for constant quantitative ratios of the exchange gases and a heat exchange process

Info

Publication number
CA2073573A1
CA2073573A1 CA 2073573 CA2073573A CA2073573A1 CA 2073573 A1 CA2073573 A1 CA 2073573A1 CA 2073573 CA2073573 CA 2073573 CA 2073573 A CA2073573 A CA 2073573A CA 2073573 A1 CA2073573 A1 CA 2073573A1
Authority
CA
Canada
Prior art keywords
gas
heat exchanger
exchanger tubes
nest
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
CA 2073573
Other languages
French (fr)
Inventor
Richard Heumueller
Reinhold Meuser
Otto Thiel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Evonik Operations GmbH
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of CA2073573A1 publication Critical patent/CA2073573A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F27/00Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus
    • F28F27/02Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus for controlling the distribution of heat-exchange media between different channels
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09CTREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
    • C09C1/00Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/44Carbon
    • C09C1/48Carbon black
    • C09C1/50Furnace black ; Preparation thereof
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28HEAT EXCHANGE IN GENERAL
    • F28DHEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D21/00Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
    • F28D2021/0019Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
    • F28D2021/0077Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for tempering, e.g. with cooling or heating circuits for temperature control of elements

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Pigments, Carbon Blacks, Or Wood Stains (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE

A nest of heat exchanger tubes is introduced for heating a gas which is at a low temperature by means of a gas at a high temperature to variable temperatures ranging from the maximum for which the installation is designed to a lower value, using a given quantitative ratio of the two gases, which heat exchanger has at least one additional intake pipe connection for the low temperature gas situated in the lower region of the housing, between the intake pipe connection and discharge pipe connection for the gas to be heated, near the inflow of heating gas, and connected with a device for measuring the quantities. The system is particularly useful for producing different types of carbon black.

Description

2073~7~

This invention relates to a nest of heat exchanger tubes for heating a gas which is at a low temperature by means of a gas - at a high temperature to variable temperatures ranging from the maximum for which the installation is designed to a value below this maximum, using a given constant quantitative ratio between the two gases, in particular for the preheating of reactor air in the production o~ furnace black by means of soot-laden hot process gas, consisting of a housing which J
when the heat exchanger is placed vertically, is open at the top and bottom, and has pipe connections for the intake and discharge of the gas to be heated opening laterally at the top and bottom, which housing is closed at the top and bottom by a tube plate provided with apertures for receiving the exchanger tubes, exchanger tubes fixed gas-tightly in the upper and lower tube plate, and gas supply pipes for the heating gas connected with the housing adjacent to each tube plate.

In the production of furnace black, the fuel (gas or oil) is burned with hot air in the reactor to produce the thermal energy for decomposition of the furnace black raw material into furnace black. To stop the decomposition reaction and adjust the in}et temperature for the subseguent heat exchanger for preheating the reactor air to 400 - 800C, the process gas is cooled to 750 - 960C by the injection of water.

The ratio by weight of process gas (after the injection of water) to reactor air is approximately 1.8 : 1 and cannot easily be changed. Consequently, if a heat exchanger is designed for preheating air to 800C, which is a temperature providing high yields for many qualities of carbon black, lower air temperatures down to about 400C such as are 2~73~73 required for special types of carbon black can only be achieved with the injection of very large quantities of - water, which is a serious disadvantage for the reactor and the subsaquent apparatus such as heat exchangers and filters and for the subsequent use of the residua:L gas left over after separation of the carbon black.

The admixture of cold air from a by-pass to lower the temperature can only be carried out within very narrow limits because at the constant quantitative ratios which are to be maintained between the process gas and the reactor air, the very high temperatures still prevailing, which are close to the limit of tolerance for metallic materials, entail the risk of overheating and destruction of the tubes of the heat exchanger which is situated upstream of the filter installation.

In view of the fixed ratio between process gas and reactor air required for the production of certain carbon blacks, the admixture of cold air must be accompanied by discharge of part of the reactor air which has been taken in from the surroundings and compressed and heated in the heat exchanger in order to keep the quantitative ratio constant; this entails great energy losses and expense in regulating the system.

To overcome this difficulty, the invention provides that in a heat exchanger designed for preheating air to 800C, lowering of this temperature to values ranging from 800 to 300, preferably fro~ 600 to 350 and in particular to 400C, is - achieved by subdividing the intake of air in counter-current so that part of the air is introduced through a suitable opening downstream of the normal location for introduction of , .

2~3573 the air. As a result, the heat exchange surface is reduced for this part of the air which is introduced at a later stage - and the preheating temperature becomes lower; the part of the heat exchanger which is subjected to high stresses by temperature is nevertheless still sufficiently well cooled.

The present invention thus relates to a nest of heat exchanger tubes for heating a gas of low temperature by means of gas at a high temperature to variable temperatures ranging from the maximum for which the installation is designed to a lower value, using a given constant quantitative ratio between the two gases, in particular for the preheating of reactor air in the production of furnace black by means of soot laden hot process gas, consisting of a housing which, when the heat exchanger is placed vertically, is open at the top and bottom and has pipe connections for the intake and discharge of the gas to be heated opening laterally into the housing at the top and bottom, which housing is closed at the top and bottom by a tube plate provided with apertures for receiving the exchanger tubes, exchanger tubes gas-tightly fixed in the upper and lower tube plate, and gas supply pipes for the heating gas connected with the housing in a position adjacent to each tube plate.

The subject matter of the invention is characterised in that at least one additional supply pipe connection for the gas of low temperature opens into the lower region of the housing between the intake pipe connection and the discharge pipe connection for the gas to be heated, in a region of the housing near the lower inflow of the heating gas, which additional pipe connection is connected with a device for adjustment of the quantities.

2~73~73 The function of the heat exchanger according to the invention is particularly efficient when the additional pipe connection -- is situated at least below half th~ distance between the ; intake connection and the discharge connection for the gas to be heated but preferably at a distance whi.ch, m~asured from tha d.ischarge pipe connection for the gas to be heated, amounts to 10 to 60%, preferably 20 to 40~, in particular 30%
of the said half distance. With this arrangement, a partial stream of the total quantity of the gas to be heated is subjected to only a limited heat exchange.

The supply of the partial stream, which is subjected later to heat exchange, is particularly advantageous when arrangements are made to ensure that this partial stream is rapidly and . uniformly distributed over the whole internal cross section of the housing of the heat exchanger.

According to preferred and advantageous embodiments of the invention, a plurality of additional intake pipe connections may be arranged in stellate formation in at least one plane or at least one additional intake pipe connection may open into an annular channel mounted on the housing or worXed into the housing with gas openings into the interior of the housing.

According to one simple and yet effective embodiment, three additional intake pipe connections situated in a horizontal plane open into the lower region of the housing, near the inflow of heating gas, for the distribution of gas of low temperature.

The invention further relates to a fundamental process, i.e.
a process not limited to the particular construction of heat 20~73 exchanger tubes described above, for heat:ing a gas of low temperature by means of a gas at high temperature to variable temperatures ranging from the maximum for which the installation is designed to a lower valu~l, using a given constant ratio between the two gases, by heat exchange in counter-currentl in particular using -the nest of heat exchanger tubes described above. The process is characterised in that the gas to be heated is subdivided into two streams, one stream being subjected to the total heat exchange capacity provided while the complementary stream is subjected to only part of the total heat exchange capacity at the end near the inflow of heating gas, and the desired final temperature of the heated gas is obtained by adjusting the quantity of the complementary stream.

Lastly, the invention relates to the use of the nest of heat exchanger tubes according to the invention for the predetermined preheating of reactor air by means of soot laden hot process gas in the production of furnace black.

In the production of furnace black, adjustment of the surface areas of carbon hlack to the desired value is brought about mainly by adjusting the ratio of the total thermal energy introduced into the carbon black reactor to the quantity of carbon black raw material oil not consumed for the production of energy.

The more energy is introduced into the reactor, e. g. by the preheatin~ of air, the more carbon black raw material can be continuously converted into carbon black by heat at othexwise constant quantitative flow rates. The usual coefficient of this ratio is the so-called "oil charge" of a furnace black reactor. It depends not only on the above-mentioned : ~73573 preheating of air but also inter alia on the desired surface area of carbon blac]c, the raw material for the carbon black and the construction of the reactor.
.
Each type of carbon black has its individual optimum of preheating of combustion air. As a rule, howev~r, a production line is re~uired to produce various typ~s of carbon black each having its different optimum air preheating temperature. Adjustment of the temperature to which the air is preheated has hitherto only been possible by adju~ting the quantity of quenching water injected into the furnace reactor and has therefore been very limited. The rule thus applies that the higher the temperature to which the air is preheated, the higher is the possible charging with oil and the higher the production output and yield of carbon black.

For certain types of carbon black, however, the extent to which air can be preheated in a given reactor is limited because impurities in the form of coke and oil residues occur in the carbon black if a critical oil charge is exceeded.

The nest of heat exchanger tubes according to the invention provides for increased flexibility in a given production plant in that the maximum preheating of air need not always be kept at a low level on account of the above mentioned individual types of carbon black; instead, for all other types of carbon black the air may be preheated to the temperatures at which production can be carried out under economically optimum conditions.

The invention will be described below with the aid of a functional description of a nest of heat exchanger tubes j 20~3~73 according to the invention shown in Figure 1 and its flow chart shown in Figure 2 for the thermal utilization of - process gas in a furnace black installation, and it will be further explained with the aid of an example for the production of a carbon black.

In Figure 1 ~Figure la and Figure lb~, a preferred embodiment of the construction of heat exchanger according to the invention comprises a housing 1 open at the top and bottom, provided with a pipe connection ~ opening laterally into the lQ housing at the top and three pipe connections 3, 4 and 5 opening laterally at a lower level for the supply of gas to be heated and a pipe connection 6 opening laterally at the lower end for the discharge of the heated gas. The housiny is closed at the bottom and top by tube plates 8 and 9 provided with apertures for receiving the exchanger tubes 7.
Gas supply pipes 10 for the heating gas are connected with the housing in a position adjacent to each tube plate. Three intake pipe connections 3, 4 and 5 for gas at a low temperature open into the lower region of the housing, near the inflow of heating gas, between the intake pipe connection 2 and the discharge pipe connection 6 for the gas to be heated; these three pipe connections 3, 4 and 5 are connected with a device 11 for adjustment of the quantities. The said intake pipe connections are connected with a supply pipe and arranged so that they distribute the gas uniformly round the tubes of the heat exchanger.

The process according to the invention for adjustment of the temperature of the gas to be heated takes place as follows when carried out in the apparatus described above. The gas at low temperature is subdivided into two streams 12 and 13 as shown in Figure 2; the partial stream 12 is subjected to 2~3~73 the total heat exchange capacity provided and the complementary stream 13 i5 subjected to only part of the total heat exchange capacity at the end neax the inflow of heating gas. The desired final temperature of tha heated gas is obtained by adjusting the quantity of thP comp}ementary stream 13 by means of the device 11.
;
ExamPle The production of a furnace black in an installation designed for the universal production of the entire range of furnace blacks is described. The said installation comprises a heat exchanger according to the invention designed for the maximum amount of heating occurriny~

Two production runs A (with high preheating of air) and B
twith preheating of air reduced by the heat exchanger according to the invention) are compared with one another.
Run A is carried out with reactor air preheated to 650C and run B with reactor air lowered to 350C. Both runs are carried out with the same quantity of reactor air and quantity of natuxal gas. The parameters for A and B are 20 adjusted for obtaining furnace blacks of the same specific surface area and structure. The value of transmission shown in the Table is the optical permeability to light of a furnace black extract obtained by means of toluene. The higher the given number, the lower is the quantity of unwanted oil residue on the furnace black.

Whereas in run A the transmission of carbon black is low and the grit value relatively high, a high transmission and substantially lower grit content are obtained in B. Only run B entirely satisfies the specified quality requirements.

2~73~73 This desired effect i5 achieved by preheating air to a lower temperature in the heat exchanger according to the invention.
- The heat input for the less preheated air is reduced and the charge of carbon black oil thereby also reduced.

In a production plant designed for universal production of a wide range of furnace black types, the level to which the air is generally preheated need not be limitad on account of the furnace black given by way of example (350C in the Example);
on the contrary, *or the production of types of furnace black which are less sensitive in this respect, considerably higher temperatures may be employed and the plant can therefore be operated more economically.

All the data are given in the following Table and show that the quality of furnace black can easily be influenced by means of the heat exchanger according to the invention.

207~73 Table A
.
Quantity of reactor air Nm3~h 3500 3500 Preheating of reactor air C 650 350 Quantity o* natural gas Nm3/h 215 215 Heat input by preheated air and natural gas MJ/h3120 1620 Total energy input plus heat of combustion of natural gas MJ/h10700 9200 Furnace black raw material oil kg/h1765 1708 Analytical data of furnace Nominal value black-Transmission 425 nm according to DIN D 161~-83 % > 80 62 95 Grit content > 325 mesh according to DIN 53 580 ppm S 300 430 90 : 20

Claims (17)

1. Nest of heat exchanger tubes for heating a gas at low temperature by means of a gas at high temperature to variable temperatures ranging from the maximum for which an installation is designed to a lower value at a given constant quantitative ratio of the two gases, comprising: a housing which, when the heat exchanger is placed vertically, is open at the top and bottom and has pipe connections for the intake and discharge of the gas to be heated opening laterally at the top and bottom, which housing is closed at the top and bottom by a tube plate provided with apertures for the passage of exchanger tubes, said exchanger tubes fixed gas-tightly in the upper and lower tube plate and gas suppoly pipes for the heating gas connected to the housing in a position adjacent to each tube plate, wherein at least one additional intake pipe connection for the gas of low temperature, fitted with means for adjusting the quantities, opens into the housing in the lower region of the housing in a position between the intake and discharge pipe connections for the gas to be heated, near the inflow of the heating gas.
2. Nest of heat exchanger tubes according to Claim 1, wherein the additional intake pipe connection is arranged in a position at least below half the distance between the intake connection and discharge connection for the gas to be heated.
3. Nest of heat exchanger tubes according to Claim 2, whrein the additional intake pipe is in a position which, measured from the discharge connection for the gas to be heated, is at a distance amounting to 10 to 60%.
4. Nest of heat exchanger tubes according to Claim 3, wherein said distance amounts to 20 to 40%.
5. Nest of heat exchanger tubes according to Claim 4, wherein said distance amounts to 30%.
6. Nest of heat exchanger tubes according to Claim 1, wherein a plurality of additional pipe connections is arranged in stellate formation in at least one plane.
7. Nest of heat exchanger tubes according to Claim 1, wherein at least one additional intake pipe connection opens into an annular channel mounted on the housing or worked into the housing, with gas openings into the interior of the housing.
8. Nest of heat exchanger tubes according to Claim 1, wherein three additional intake pipe connections situated in a horizontal plane open into the lower region of the housing, near the inflow for heating gas, for distributing the gas of low temperature.
9. Nest of heat exchanger tubes according to any one of Claims 1 to 8, adapted for preheating reactor air in the production of furnace black by means of soot laden hot gases.
10. A process for heating a gas of low temperature by means of a gas at high temperature to variable temperatures ranging from the maximum for which an installation is designed to a lower value by heat exchange in counter-current, using a given constant quantitative ratio between the two gases, wherein the gas to be heated is subdivided into two streams, one stream being subjected to the total heat exchange capacity provided while the complementary stream is subjected to only part of the total heat exchange capacity on the side near the inflow of heating has and the desired final temperature of the heated gas is adjusted by adjusting the quantity of the complementary stream.
11. The process of Claim 10, wherein the variable temperature is in the range 800 to 300°C.
12. The process of Claim 11, wherein the temperature is in the range 600 to 350°C.
13. The process of Claim 12, wherein the temperature is 400°C.
14. The process of Claim 11, adapted for the. production of carbon black.
15. The process of any one of Claims 10 to 14, effected in the rest of heat exchanger tubes of any one of Claims 1 to 8.
16. Use of the nest of heat exchanger tubes according to any one of Claims 1 to 8 for the predetermined preheating of reactor air in the production of furnace black by means of soot laden hot process gas.
17. Use of the nest of heat exchanger tubes according to any one of Claims 1 to 8 for the predetermined preheating of reactor air in the production of semi-active qualities of furnace black by means of soot laden hot process gas.
CA 2073573 1991-07-13 1992-07-10 Temperature variable nest of heat exchanger tubes for constant quantitative ratios of the exchange gases and a heat exchange process Abandoned CA2073573A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP4123243.7 1991-07-13
DE19914123243 DE4123243A1 (en) 1991-07-13 1991-07-13 TEMPERATURE VARIABLE TUBE BUNDLE HEAT EXCHANGER FOR CONSTANT QUANTITY RATIO OF EXCHANGE GAS AND HEAT EXCHANGE PROCESS

Publications (1)

Publication Number Publication Date
CA2073573A1 true CA2073573A1 (en) 1993-01-14

Family

ID=6436067

Family Applications (1)

Application Number Title Priority Date Filing Date
CA 2073573 Abandoned CA2073573A1 (en) 1991-07-13 1992-07-10 Temperature variable nest of heat exchanger tubes for constant quantitative ratios of the exchange gases and a heat exchange process

Country Status (6)

Country Link
EP (1) EP0523436A3 (en)
JP (1) JPH05187788A (en)
CA (1) CA2073573A1 (en)
CZ (1) CZ216592A3 (en)
DE (1) DE4123243A1 (en)
PL (1) PL295246A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4408087C2 (en) * 1994-03-10 1997-05-22 Schilling Heinz Kg Process for operating a heat exchanger system for recuperative heat exchange
DE19518323A1 (en) * 1995-05-18 1996-11-21 Calorifer Ag Heat exchange between process and cooling fluids
SE506894C2 (en) * 1995-12-04 1998-02-23 Edmeston Ab Pipe heat exchanger with double-walled jacket and process and plant for the production of carbon black
DE10312788A1 (en) 2003-03-21 2004-09-30 Behr Gmbh & Co. Kg Exhaust gas heat exchanger and sealing device for exhaust gas heat exchanger
DE102009043712A1 (en) * 2009-10-01 2011-04-07 Hampe & Liedtke heat exchangers
US9828275B2 (en) 2013-06-28 2017-11-28 American Air Liquide, Inc. Method and heat exchange system utilizing variable partial bypass

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE229567C (en) *
GB601609A (en) * 1944-06-23 1948-05-10 Sulzer Ag Improvements in or relating to the regulation of gas heaters
US2989952A (en) * 1957-12-23 1961-06-27 Frederick W Richl Combustion air preheater
DE1592864C3 (en) * 1967-08-11 1975-05-22 Deutsche Gold- Und Silber-Scheideanstalt Vormals Roessler, 6000 Frankfurt Method of making FurnaceruB
BE793928A (en) * 1972-01-13 1973-05-02 Deggendorfer Werft Eisenbau APPARATUS FOR IMPLEMENTING EXOTHERMAL AND ENDOTHERMAL CHEMICAL PROCESSES
DE2846455C2 (en) * 1978-10-23 1980-07-31 Borsig Gmbh, 1000 Berlin Shell and tube heat exchanger with a constant outlet temperature of one of the two media
US4737531A (en) * 1985-01-24 1988-04-12 Phillips Petroleum Co. Waste heat recovery
DE3828034A1 (en) * 1988-08-18 1990-02-22 Borsig Gmbh HEAT EXCHANGER

Also Published As

Publication number Publication date
PL295246A1 (en) 1993-02-08
JPH05187788A (en) 1993-07-27
CZ216592A3 (en) 1993-02-17
EP0523436A2 (en) 1993-01-20
DE4123243A1 (en) 1993-01-14
EP0523436A3 (en) 1993-05-26

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