CA1189685A - Arrangement for transferring the heat and levelling the heat profile in installations for the production of phthalic anhydride - Google Patents
Arrangement for transferring the heat and levelling the heat profile in installations for the production of phthalic anhydrideInfo
- Publication number
- CA1189685A CA1189685A CA000370705A CA370705A CA1189685A CA 1189685 A CA1189685 A CA 1189685A CA 000370705 A CA000370705 A CA 000370705A CA 370705 A CA370705 A CA 370705A CA 1189685 A CA1189685 A CA 1189685A
- Authority
- CA
- Canada
- Prior art keywords
- heating
- heat
- circuit
- steam
- separators
- 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.)
- Expired
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0006—Controlling or regulating processes
- B01J19/0013—Controlling the temperature of the process
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P31/00—Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
- A61P31/12—Antivirals
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00074—Controlling the temperature by indirect heating or cooling employing heat exchange fluids
- B01J2219/00105—Controlling the temperature by indirect heating or cooling employing heat exchange fluids part or all of the reactants being heated or cooled outside the reactor while recycling
- B01J2219/00108—Controlling the temperature by indirect heating or cooling employing heat exchange fluids part or all of the reactants being heated or cooled outside the reactor while recycling involving reactant vapours
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- General Chemical & Material Sciences (AREA)
- Medicinal Chemistry (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Communicable Diseases (AREA)
- Pharmacology & Pharmacy (AREA)
- Virology (AREA)
- General Health & Medical Sciences (AREA)
- Oncology (AREA)
- Veterinary Medicine (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Furan Compounds (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Fats And Perfumes (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Fertilizers (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
Abstract
Abstract of the Disclosure: In installations for the production of phthalic anhydride, the reaction product is precipitated in a solid form on heat exchange sur-faces of separators, and is subsequently melted off again, by alternately cooling and heating the separators.
The arrangement employed, according to the invention, for transferring the heat and for levelling out the tempera-ture profiles (in which, in the heating phases, there is a peak demand for heating steam, which impedes the useful generation of steam by the exothermic reaction), com-prises a heat transfer system consisting of three circuits at different temperatures. A storage circuit (hot oil circuit) at a higher temperature is superposed on the heating circuit operating at a pre-determined temperature. Using the hot oil circuit, the separators are provided, during the heating phase, with the heat required to melt off the reaction product.
This superposition of 3 circuits at different tempera-tures produces a levelling of the steam requirement and hence allows more effective utilization of the excess steam.
The arrangement employed, according to the invention, for transferring the heat and for levelling out the tempera-ture profiles (in which, in the heating phases, there is a peak demand for heating steam, which impedes the useful generation of steam by the exothermic reaction), com-prises a heat transfer system consisting of three circuits at different temperatures. A storage circuit (hot oil circuit) at a higher temperature is superposed on the heating circuit operating at a pre-determined temperature. Using the hot oil circuit, the separators are provided, during the heating phase, with the heat required to melt off the reaction product.
This superposition of 3 circuits at different tempera-tures produces a levelling of the steam requirement and hence allows more effective utilization of the excess steam.
Description
O ~ Z r 0050/0343 2 4 Arrangement for transferring the heat and levelling the heat profile in installations ~or the prod~ction of phthalic anhydride The invention relates, in general terms, to produc-tion installations in which the reac-tion product is precipitated, in cyclic cooling phases9 in a solid form on the cooled inner surface of separa-tors, and is melted of~ again, by supply of heat, in the subsequent cyclic heating phases o~ the same heat exchanger surfaces, and is discharged from the separator.
In particular, the invention relates to an arrangement for transferringthe hea-tand for levelling~out the tempera-lo ture pro~iles ir. an installation for the production of phthalic anhydride (PA), possessing one or more heating and cooling circuitsfor the cyclically alternating heat-i~g andcooling of a plurality of product separators, in which arrangement a peak demand for heating steam occurs in the heating phases, which impedes the useful genera-tion of steam by the exothermic reaction.
Processes for heat recovery in the gas phase oxidation of hydrocarbons in a tube-bundle heat exchanger, with a fluid heat transfer medium circulating on the jacket side, have already been disclosed; in these, steam is generated, via the heat transfer mediumg by means of a part of the heat of reac-tion, and the remaining heat of reaction evolved, which is subject to considerable periodic fluctuation9 is used to superheat the steam generated by the above part of the heat of reactionO Howeverg
In particular, the invention relates to an arrangement for transferringthe hea-tand for levelling~out the tempera-lo ture pro~iles ir. an installation for the production of phthalic anhydride (PA), possessing one or more heating and cooling circuitsfor the cyclically alternating heat-i~g andcooling of a plurality of product separators, in which arrangement a peak demand for heating steam occurs in the heating phases, which impedes the useful genera-tion of steam by the exothermic reaction.
Processes for heat recovery in the gas phase oxidation of hydrocarbons in a tube-bundle heat exchanger, with a fluid heat transfer medium circulating on the jacket side, have already been disclosed; in these, steam is generated, via the heat transfer mediumg by means of a part of the heat of reac-tion, and the remaining heat of reaction evolved, which is subject to considerable periodic fluctuation9 is used to superheat the steam generated by the above part of the heat of reactionO Howeverg
- 2 ~ oOz. 0050/034324 optimum b~l~n~ o~ the dif~erent temperatureprofilesasbe~
ween the heating phases and cocling phases is not achie~able with this type of heat utiliza-tion arrange-ment.
In the conventional design of heat transfer circuit for cooling and heating the PA separators 9 there i~, periodically, a very high peak demarld for heating steam. Thispeak demandis in general supplied from existir~
steam gridsin theproduction plant 7 although the -total amount of heat generated by the exothermic reaction is in excess oYer the requirement~ This disadvantage or shortcoming arises particularly in the case of rela-tively small installations for the manufacture of phthalic anhydride, maleic anhydride and the like, where substantialbalancing-out of the temperaturepro-files is not achievable because of the lack o~ a sizable steam grid for taking up, and releasing, the heat.
It is an object of the presen-t invention to modify the conventional heat transfer circuits, ie, the cold oil circuit ~or the cooling phases of the separator or separa-tors, and the hot oil circuit for melting off the preci~i-tated product,soth~t substantially more uniform temperatureprofiles result and the excess heat released by the exothermicity of the process can be employed more economically.
I have found that this object is achieved by superposing, on the heating circuit operating at a pre-determined temperature, a stora~e circuit which is at a higher temperature and through which a heat transfer medium is forcibly conveyed~ According to a further embodiment of the invention, the same heat transfer medium .is employed in the heating and storage circuits, so that heat can be transferred rom the storage circuit to the heating circuit by periodically opening a mixing valve.
In particular, the present invention provides an arrangement for transferring heat and levelling out temperature profiles for plan~s for the production of phthalic anhydride or maleic anhydride, comprising at least one heating circuit and at least one cooling circuit for the cyclically alternating heating and cooling of one or more product separators wherein product is separated by indirect heat exchange, product being deposited in solid form in a separator during a cooling cycle and being melted off and discharged therefrom during a heating cycle~ said arrangement being characterized in that, - each heating circuit, operating at a predetermined temperature, has superposed on it a storage circuit which is at a higher temperature and through which a heat transfer medium is forcibly conveyed, - the same heat transfer medium is employed in the storage and heating circuit, and - heat from the storage circuit is transferred to the heating circuit by mixing.
In the drawings, Figure 1 shows a preferred arrangement according to the invention, of the interlinked circuits, whilst Figures 2 and 3 diagrammatically show the advantages resulting from the invention.
As shown in Figure 1, the heat transfer system according to the invention, which will be described, by way of example, for a plant for the product on of phthalic anhydride, comprises three circuits at different temperature levels. The cold oil circuit consists of the cold oil tank 1, , ~ , - 3a -the circulating pump 2, the oil filter 3 and the oil cooler 4 and serves to cool one or more product separators 11. The hot oil circuit or heating circuit, which is employed for periodically heating the product separators 11 r ie. for melting off the sublimed product, consists of the hot oil tank 5, the circulating pump 6 and the oil filter 7. The product separators 11 for phthalic anhydride installations are multi~way heat exchangers, whose mode of operation, with successive heating and cooling phases, is generally known. Figure 3 shows, in an idealized diagrammatic manner, the sawtooth lines which represent the time sequence of the heating phases of the separators /
/
_ 4 _ O.z~ 0050/034324 11 of a particular installation.
The storage circuit consists Qf the heat store 89 -the circulating pump 9 and the heater 10 The transfer of heat to the hot oil circuit takes place at the mixing point M~ Advantageously~ the same heat transfer medium is employed in the storage and heating circuits9 for ex -am~e a mixture of diphenyl and diphenyl oxide~ here-after simply referred to as oil. In the heater lO, con~
structed as a-two~wayheat exchanger, thisoilisbrought, by means o~ an existing steam grid, to a -temperature above that of the same heat transfer medium in the hot oil circuit, which includes the tank 5 and the circulating pu~p 6.
The storage circuit is linked to the steam grid in the unit 12. The latter is pre~erably a steam-saturated condensate collector, in which the excess steam from the exothermic reaction is saturated by refluxing ondensate and is then fed to the heater 10.
In the heating phases of the separators 11, the heat required to melt off the product ~hich has sublimed and deposited is supplied by means of the hot oil cir-cuit For this purpose, hot oil, which has been heated by means of the storage circuit~ is pumped by the pump 6 from the tank 5 into one or more of the separators 11~ As a result, the oil cools and must therefore be brought back to a higher temperature by supplying hotter oll from the store 8. The supply of hotter oil from the store 8 is automatically regulated as a function of the temperature of the hot oil leaving $~
O.Z. 0050/0~324 the tank 5. The liquid level in the store 8 is kept constant by taking heat transfer medium ~rom the return line of the hot oil circuit.
This causes the store 8 to cool gradually.
After a certain time, the separators 11 have reached approximately the same temperature as that of the hot oil, and no fur-ther hot oil need be supplied from the store 8. At this poin-t in time, the temperature of the heat transfer medium in the storage circuit has also reached its lowest value. For the remainder of the melting-off of the product 9 the amount of hot oil added at the mixing point M is only as much as is needed to compensate for heat losses. During this time, the con-tents of the store 8 are again heated to their original temperature. FOr this purpose, the contents of the store 8 are constantly circulated through the heater 10 by means of the pump 9~ The amount of heating steam to be supp]ied to -the heater 10 is regula-ted so as to be the same over the entire cycle, and thus corresponds to the average hea-t requirement of the hot oil system.
The tempera-ture variation in the store 8, in the hot oil feedline and in the hot oil return line are shown diagrammatically in Figure 2. Curve a shows the variation with time, in the store 8, over one cycle;
the temperature of the hot oil feed to the separator 11 is marked b in Figure 2. The temperature in the tank 5 falls, at the start of the melting-off sequence - 6 - . O~Z, C050/034324 in the separators 11, to an extremely low value and then rises, as shown by the curve c, untii it reaches the same value as the hot oil feed temperature indicated by line b. The variation with time of the temperature of the hot oil return from the separator 11 to the tank 5 is indicated by the line d.
A precondition for proper ~unctioning of the above system of three linked circuits is that the capacity of the store, the storage temperature of the storage circuit, and the amount o~ steam are carefully balanced. . Under these conditions, the following important advantages result:
1. Smoothing of the steam requirement, permitting better utilization of the excess steam even where there is no sizable steam grid available (see Example 1 below).
2. Substantial reduction in the heating time, and hence longer availability of the separators ~or deposition.
ween the heating phases and cocling phases is not achie~able with this type of heat utiliza-tion arrange-ment.
In the conventional design of heat transfer circuit for cooling and heating the PA separators 9 there i~, periodically, a very high peak demarld for heating steam. Thispeak demandis in general supplied from existir~
steam gridsin theproduction plant 7 although the -total amount of heat generated by the exothermic reaction is in excess oYer the requirement~ This disadvantage or shortcoming arises particularly in the case of rela-tively small installations for the manufacture of phthalic anhydride, maleic anhydride and the like, where substantialbalancing-out of the temperaturepro-files is not achievable because of the lack o~ a sizable steam grid for taking up, and releasing, the heat.
It is an object of the presen-t invention to modify the conventional heat transfer circuits, ie, the cold oil circuit ~or the cooling phases of the separator or separa-tors, and the hot oil circuit for melting off the preci~i-tated product,soth~t substantially more uniform temperatureprofiles result and the excess heat released by the exothermicity of the process can be employed more economically.
I have found that this object is achieved by superposing, on the heating circuit operating at a pre-determined temperature, a stora~e circuit which is at a higher temperature and through which a heat transfer medium is forcibly conveyed~ According to a further embodiment of the invention, the same heat transfer medium .is employed in the heating and storage circuits, so that heat can be transferred rom the storage circuit to the heating circuit by periodically opening a mixing valve.
In particular, the present invention provides an arrangement for transferring heat and levelling out temperature profiles for plan~s for the production of phthalic anhydride or maleic anhydride, comprising at least one heating circuit and at least one cooling circuit for the cyclically alternating heating and cooling of one or more product separators wherein product is separated by indirect heat exchange, product being deposited in solid form in a separator during a cooling cycle and being melted off and discharged therefrom during a heating cycle~ said arrangement being characterized in that, - each heating circuit, operating at a predetermined temperature, has superposed on it a storage circuit which is at a higher temperature and through which a heat transfer medium is forcibly conveyed, - the same heat transfer medium is employed in the storage and heating circuit, and - heat from the storage circuit is transferred to the heating circuit by mixing.
In the drawings, Figure 1 shows a preferred arrangement according to the invention, of the interlinked circuits, whilst Figures 2 and 3 diagrammatically show the advantages resulting from the invention.
As shown in Figure 1, the heat transfer system according to the invention, which will be described, by way of example, for a plant for the product on of phthalic anhydride, comprises three circuits at different temperature levels. The cold oil circuit consists of the cold oil tank 1, , ~ , - 3a -the circulating pump 2, the oil filter 3 and the oil cooler 4 and serves to cool one or more product separators 11. The hot oil circuit or heating circuit, which is employed for periodically heating the product separators 11 r ie. for melting off the sublimed product, consists of the hot oil tank 5, the circulating pump 6 and the oil filter 7. The product separators 11 for phthalic anhydride installations are multi~way heat exchangers, whose mode of operation, with successive heating and cooling phases, is generally known. Figure 3 shows, in an idealized diagrammatic manner, the sawtooth lines which represent the time sequence of the heating phases of the separators /
/
_ 4 _ O.z~ 0050/034324 11 of a particular installation.
The storage circuit consists Qf the heat store 89 -the circulating pump 9 and the heater 10 The transfer of heat to the hot oil circuit takes place at the mixing point M~ Advantageously~ the same heat transfer medium is employed in the storage and heating circuits9 for ex -am~e a mixture of diphenyl and diphenyl oxide~ here-after simply referred to as oil. In the heater lO, con~
structed as a-two~wayheat exchanger, thisoilisbrought, by means o~ an existing steam grid, to a -temperature above that of the same heat transfer medium in the hot oil circuit, which includes the tank 5 and the circulating pu~p 6.
The storage circuit is linked to the steam grid in the unit 12. The latter is pre~erably a steam-saturated condensate collector, in which the excess steam from the exothermic reaction is saturated by refluxing ondensate and is then fed to the heater 10.
In the heating phases of the separators 11, the heat required to melt off the product ~hich has sublimed and deposited is supplied by means of the hot oil cir-cuit For this purpose, hot oil, which has been heated by means of the storage circuit~ is pumped by the pump 6 from the tank 5 into one or more of the separators 11~ As a result, the oil cools and must therefore be brought back to a higher temperature by supplying hotter oll from the store 8. The supply of hotter oil from the store 8 is automatically regulated as a function of the temperature of the hot oil leaving $~
O.Z. 0050/0~324 the tank 5. The liquid level in the store 8 is kept constant by taking heat transfer medium ~rom the return line of the hot oil circuit.
This causes the store 8 to cool gradually.
After a certain time, the separators 11 have reached approximately the same temperature as that of the hot oil, and no fur-ther hot oil need be supplied from the store 8. At this poin-t in time, the temperature of the heat transfer medium in the storage circuit has also reached its lowest value. For the remainder of the melting-off of the product 9 the amount of hot oil added at the mixing point M is only as much as is needed to compensate for heat losses. During this time, the con-tents of the store 8 are again heated to their original temperature. FOr this purpose, the contents of the store 8 are constantly circulated through the heater 10 by means of the pump 9~ The amount of heating steam to be supp]ied to -the heater 10 is regula-ted so as to be the same over the entire cycle, and thus corresponds to the average hea-t requirement of the hot oil system.
The tempera-ture variation in the store 8, in the hot oil feedline and in the hot oil return line are shown diagrammatically in Figure 2. Curve a shows the variation with time, in the store 8, over one cycle;
the temperature of the hot oil feed to the separator 11 is marked b in Figure 2. The temperature in the tank 5 falls, at the start of the melting-off sequence - 6 - . O~Z, C050/034324 in the separators 11, to an extremely low value and then rises, as shown by the curve c, untii it reaches the same value as the hot oil feed temperature indicated by line b. The variation with time of the temperature of the hot oil return from the separator 11 to the tank 5 is indicated by the line d.
A precondition for proper ~unctioning of the above system of three linked circuits is that the capacity of the store, the storage temperature of the storage circuit, and the amount o~ steam are carefully balanced. . Under these conditions, the following important advantages result:
1. Smoothing of the steam requirement, permitting better utilization of the excess steam even where there is no sizable steam grid available (see Example 1 below).
2. Substantial reduction in the heating time, and hence longer availability of the separators ~or deposition.
3. Scope for periodically raising the temperature of the oil to 250C, so as to decompose corrosive sub~
s~ances present on the tube bundles of the separators 11.
In this way, the li~e of the separators can be substan-tially increasedO
Four separators are e~ployed in a phthalic anhydride production installation~ A cycle involves the following: the separators are charged in the course of 4~5 hours; this constitutes the cooling phaseO The separators are then heated -to O~ZO 0050~034324 190C in the course o~ 40 minutes and kept at the same temperature for a further 20 minutes 9 SO as to melt off the sublimed product The separators are then cooled again for 30 minutesN
~he heat re~uiremen~ -for one cycle is 600,000 kcal. For simplicity~
losses due to imperfect insulation ha~e been le~t out of account, Figure 3 shows how the conditions compare with the con~entional processes without a storage circuit. The variation of steam consumption with time, in prior art installations, is shown in continuous lines. In the same installation, the variation of steam consumption with time, using a correctly balanced storage system, is constan-t, as shown by the dot-dash line in Figure 3. The symbols have the following meanings:
MD max = maximum amount of steam which must be kept available in order to hea-t the separator to 200C in the course of 49 minutes; in the particular Example this amount is 4.5 t/h.
~D = steam consumption, with a storage system fitted;
in the particular Example this is about 1 t/h ~MD = steam which can additionally be utilized for turbines or other continuous steam consumers;
in the particular Example, this is 3.5 t/h.
As in the case of Example 1, the time for heating up to the temperature of 190C, which then has to be ~ 8 - o.z. 0050/034324 maintained, is about 40 minutes; this limit is imposed by the maximum available amount of steam, The m; n; ml]m possible heating~-up time is however only a function of the heat transfer between the heat tran~fer oil and the separators 11, I~ the size o~ the pump 9 in the storage circuit is such that at least as much heat is transferred, at the mixing point M,from the storage circuit to the heating circuit as can be transferred from the heating circuit to the separators lo 11, the use of a store 8 as shown in Figure 1 makes it possible to match the actual heating-up time to the miniml~m possible heating-up time, ie, the heating-up time is substantially reduced, (without store) Charging time - useful time 270 minutes Heating-up time 40 minutes Constant-temperature time ~0 minutes Re-cooling time 30 minutes Cycle time 360 minutes proportion of useful time 7~ %
.EXAMPLE 4 (with store~
Charging time ^- useful time 270 minutes Heating-up time 12 minutes - Constant-temperature time 20 minutes Re-cooling time ~0 minutes Cycle time 332 minutes proportion of useful time 81 /0 _. 9 _ O,Z,, 0050/03a~32aC
Accordingly, the heating-up time can be reduced by 46% and correspondingly, in this Example, the useful time of the equipment can be increased by about 8%o
s~ances present on the tube bundles of the separators 11.
In this way, the li~e of the separators can be substan-tially increasedO
Four separators are e~ployed in a phthalic anhydride production installation~ A cycle involves the following: the separators are charged in the course of 4~5 hours; this constitutes the cooling phaseO The separators are then heated -to O~ZO 0050~034324 190C in the course o~ 40 minutes and kept at the same temperature for a further 20 minutes 9 SO as to melt off the sublimed product The separators are then cooled again for 30 minutesN
~he heat re~uiremen~ -for one cycle is 600,000 kcal. For simplicity~
losses due to imperfect insulation ha~e been le~t out of account, Figure 3 shows how the conditions compare with the con~entional processes without a storage circuit. The variation of steam consumption with time, in prior art installations, is shown in continuous lines. In the same installation, the variation of steam consumption with time, using a correctly balanced storage system, is constan-t, as shown by the dot-dash line in Figure 3. The symbols have the following meanings:
MD max = maximum amount of steam which must be kept available in order to hea-t the separator to 200C in the course of 49 minutes; in the particular Example this amount is 4.5 t/h.
~D = steam consumption, with a storage system fitted;
in the particular Example this is about 1 t/h ~MD = steam which can additionally be utilized for turbines or other continuous steam consumers;
in the particular Example, this is 3.5 t/h.
As in the case of Example 1, the time for heating up to the temperature of 190C, which then has to be ~ 8 - o.z. 0050/034324 maintained, is about 40 minutes; this limit is imposed by the maximum available amount of steam, The m; n; ml]m possible heating~-up time is however only a function of the heat transfer between the heat tran~fer oil and the separators 11, I~ the size o~ the pump 9 in the storage circuit is such that at least as much heat is transferred, at the mixing point M,from the storage circuit to the heating circuit as can be transferred from the heating circuit to the separators lo 11, the use of a store 8 as shown in Figure 1 makes it possible to match the actual heating-up time to the miniml~m possible heating-up time, ie, the heating-up time is substantially reduced, (without store) Charging time - useful time 270 minutes Heating-up time 40 minutes Constant-temperature time ~0 minutes Re-cooling time 30 minutes Cycle time 360 minutes proportion of useful time 7~ %
.EXAMPLE 4 (with store~
Charging time ^- useful time 270 minutes Heating-up time 12 minutes - Constant-temperature time 20 minutes Re-cooling time ~0 minutes Cycle time 332 minutes proportion of useful time 81 /0 _. 9 _ O,Z,, 0050/03a~32aC
Accordingly, the heating-up time can be reduced by 46% and correspondingly, in this Example, the useful time of the equipment can be increased by about 8%o
Claims
1. Arrangement for transferring heat and levelling out temperature profiles for plants for the production of phthalic anhydride or maleic anhydride, comprising at least one heating circuit and at least one cooling circuit for the cyclically alternating heating and cooling of one or more product separators wherein product is separated by indirect heat exchange, product being deposited in solid form in a separator during a cooling cycle and being melted off and discharged therefrom during a heating cycle, said arrangement being characterized in that, - each heating circuit, operating at a predetermined temperature, has superposed on it a storage circuit which is at a higher temperature and through which a heat transfer medium is forcibly conveyed, - the same heat transfer medium is employed in the storage and heating circuit, and - heat from the storage circuit is transferred to the heating circuit by mixing.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3007627.8 | 1980-02-29 | ||
| DE19803007627 DE3007627A1 (en) | 1980-02-29 | 1980-02-29 | ARRANGEMENT FOR TRANSMITTING THE HEAT AND COMPENSATING THE HEAT PROFILES IN PLANTS FOR THE PRODUCTION OF PHTHALIC ACID ANHYDRIDE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1189685A true CA1189685A (en) | 1985-07-02 |
Family
ID=6095846
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000370705A Expired CA1189685A (en) | 1980-02-29 | 1981-02-12 | Arrangement for transferring the heat and levelling the heat profile in installations for the production of phthalic anhydride |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0035173B1 (en) |
| JP (1) | JPS56138178A (en) |
| AT (1) | ATE4412T1 (en) |
| CA (1) | CA1189685A (en) |
| DE (2) | DE3007627A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3411732A1 (en) * | 1984-03-30 | 1985-10-10 | Metallgesellschaft Ag, 6000 Frankfurt | METHOD FOR PERIODICALLY HEATING THE PRODUCT SEPARATOR OF A PLANT FOR PRODUCING PHTHALIC ACID ANHYDRIDE OR MALEIC ACID ANHYDRIDE |
| DE3923834C2 (en) * | 1989-07-19 | 1994-08-04 | Helmut Dipl Ing Krause | Process for the continuous liquid separation of phthalic anhydride |
| CN113117627B (en) * | 2021-04-15 | 2022-07-12 | 濮阳市盛源能源科技股份有限公司 | Tetrahydrophthalic anhydride apparatus for producing |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1146163A (en) * | 1955-02-14 | 1957-11-07 | Exxon Research Engineering Co | Process for producing energy using waste heat |
| GB1130330A (en) * | 1965-01-04 | 1968-10-16 | Raymond Galloway Booty | Closed circuit reaction system |
| DE2548293A1 (en) * | 1975-10-29 | 1977-05-12 | Otmar Dipl Ing Schaefer | Heat exchanger alternately heated and cooled - is arranged for cooling pump to assist main pump at intervals |
-
1980
- 1980-02-29 DE DE19803007627 patent/DE3007627A1/en not_active Withdrawn
-
1981
- 1981-02-12 CA CA000370705A patent/CA1189685A/en not_active Expired
- 1981-02-19 AT AT81101163T patent/ATE4412T1/en not_active IP Right Cessation
- 1981-02-19 EP EP81101163A patent/EP0035173B1/en not_active Expired
- 1981-02-19 DE DE8181101163T patent/DE3160736D1/en not_active Expired
- 1981-02-27 JP JP2711881A patent/JPS56138178A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56138178A (en) | 1981-10-28 |
| DE3160736D1 (en) | 1983-09-15 |
| EP0035173B1 (en) | 1983-08-10 |
| JPH0348185B2 (en) | 1991-07-23 |
| DE3007627A1 (en) | 1981-09-10 |
| ATE4412T1 (en) | 1983-08-15 |
| EP0035173A1 (en) | 1981-09-09 |
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