Device and method for producing dry ice
By introducing liquid carbon dioxide supply, state transition and gaseous carbon dioxide recovery systems in the dry ice production process, the problems of carbon dioxide resource waste and environmental pollution in the existing technology are solved, and efficient utilization of resources and environmental protection in the production process are achieved.
Patent Information
- Application Number
- JP2024158281
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-09-12
- Filing Date
- 2024-09-12
- Publication Date
- 2025-03-25
AI Technical Summary
In the existing dry ice production process, excessive carbon dioxide in liquid carbon dioxide will be transformed into gaseous states during the expansion process, resulting in waste of resources and environmental pollution.
By a system that includes a supply of liquid carbon dioxide, state transitions to achieve solid dry ice production, and collection and recovery of gaseous carbon dioxide. The system includes a compressor, a heat exchanger and storage device for compressing and restoring the gaseous carbon dioxide into liquid to reduce waste.
It effectively optimizes resource utilization, reduces the loss of gaseous carbon dioxide, and reduces energy consumption and environmental impacts in the production process.
Smart Images
Figure 2025040977000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to an apparatus and method for producing dry ice. [Background technology]
[0002] Solutions are known which realize the supply of liquid carbon dioxide to a throttling element, which allows for an expansion in the production of dry ice.
[0003] One drawback of this solution lies in the fact that during the production of dry ice, a significant portion of the carbon dioxide passes into the gaseous state, which is volatile and therefore disperses in the environment. Summary of the Invention [Problem to be solved by the invention]
[0004] The object of the invention is to propose an apparatus and a method for producing dry ice that makes it possible to optimize the available resources whilst minimizing the risk of the abovementioned drawbacks. [Means for solving the problem]
[0005] The foregoing technical problem and stated objectives are substantially achieved by an apparatus and method that includes the following technical features:
[0006] More specifically, the present invention relates to a method for producing a medicament for use in a method for producing a medicament comprising the steps of: - a supply means for supplying carbon dioxide in liquid form; - means for transition of at least a portion of the carbon dioxide flowing along the supply means from a liquid state to a solid state, said state transition means resulting in the desired solidification of the carbon dioxide to produce dry ice, and the undesired formation of carbon dioxide in a gaseous state; - a system for collection and recovery of gaseous carbon dioxide, said collection and recovery system collecting gaseous carbon dioxide downstream of a state transition means; i) a compressor for compressing carbon dioxide collected downstream of the state transition means; ii) Storage means for storing the carbon dioxide coming from the compressor. A system comprising: The present invention relates to an apparatus for producing dry ice, comprising:
[0007] The device is - the compressor is a positive displacement piston compressor capable of compressing the exiting carbon dioxide at a pressure comprised between 25 bar and 28 bar; - the collection and recovery system comprises a heat exchanger providing thermal communication between the carbon dioxide downstream of the compressor and the carbon dioxide upstream of the compressor; - the storage means being means for storing liquid carbon dioxide under a pressure between 18 bar and 20 bar; It is characterized by:
[0008] The device of the present invention has the following characteristics: - the exchanger is a plate exchanger, - the system for collecting and recovering carbon dioxide comprises a line for the flow of carbon dioxide collected downstream of the storage means, said flow line comprising: - a first section upstream of the heat exchanger, - a second section extending from the exchanger downstream of the intermediate outlet to the exchanger upstream of the intermediate inlet; - The third section downstream of the exchanger To have - the system for carbon dioxide collection and recovery further comprises an electric heater disposed in the first section between the exchanger and the compressor; - the collection and recovery system comprises a check valve interposed between the compressor and the storage means; - the collection and recovery system comprising a homogenizer disposed between the compressor and the storage means; Also includes at least one of.
[0009] The present invention also provides - freezing at least a portion of the liquid carbon dioxide, thus obtaining dry ice, via a state transition means, said state transition means resulting in the desired freezing of the carbon dioxide to produce dry ice, and the undesired formation of gaseous carbon dioxide; - collecting the gaseous carbon dioxide downstream of the state transition means; - compressing the exiting carbon dioxide in gaseous state by a compressor having the form of a positive displacement piston compressor compressing said carbon dioxide at a pressure comprised between 25 bar and 28 bar, thereby converting said gaseous carbon dioxide into liquid carbon dioxide; - storing said liquid carbon dioxide in a storage means under a pressure of between 18 bar and 20 bar; - carrying out a heat exchange between liquid carbon dioxide present downstream of the compressor having a temperature between 15°C and 20°C and gaseous carbon dioxide present upstream of the compressor having a temperature between -70°C and -78.5°C; The present invention relates to a method for producing dry ice, comprising:
[0010] Further features and advantages of the present invention will become more clearly apparent from the schematic and therefore non-limiting description of an apparatus and method for producing dry ice as illustrated in the accompanying drawings, in which: [Brief description of the drawings]
[0011] [Figure 1] FIG. 1 is a schematic diagram showing an apparatus for producing dry ice according to the present invention. [Diagram 2] FIG. 1 illustrates a system for carbon dioxide collection and recovery in an apparatus for producing dry ice according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] In the accompanying drawings, the reference number 1 indicates an apparatus for producing dry ice (or, more generally, carbon dioxide in the solid state).
[0013] The device 1 comprises supply means 2 for supplying carbon dioxide in liquid state.
[0014] This supply means 2 advantageously comprises a tank 21. The supply means 2 comprises a conveying line 22 for conveying carbon dioxide in liquid state, advantageously extending from / downstream of the tank 21 (see FIG. 1). Advantageously, the carbon dioxide in the tank 21 is at a temperature below −18° C., in practice between −20° C. and −25° C., and at a pressure above 7 bar, in particular between 18 bar and 20 bar.
[0015] The apparatus 1 comprises means 20 for transition of at least a portion of the carbon dioxide in liquid state flowing along the supply means 2 (or, more precisely, along the conveying line 22) from the liquid state to the solid state. The state transition means 20 results in the desired solidification of the carbon dioxide to produce dry ice and the undesired formation of carbon dioxide in the gaseous state. The means 20 comprises / is a throttling means. Typically, the means 20 comprises / is a throttling valve. The apparatus 1 advantageously comprises a collection tank 23 for collecting the dry ice.
[0016] The device 1 comprises a system 3 for collection and recovery of gaseous carbon dioxide. The collection and recovery system 3 collects the gaseous carbon dioxide downstream of the state transition means 20. Advantageously, the collection and recovery system 3 collects the gaseous carbon dioxide in a collection tank 23. Thus, the carbon dioxide that is not converted into dry ice for any reason can be reused.
[0017] The collection and recovery system 3 includes a compressor 4 for compressing the carbon dioxide collected by the collection system 3 .
[0018] Preferably, the compressor 4 is a positive displacement compressor. More preferably, the compressor 4 is a piston compressor.
[0019] Advantageously, the compressor 4 has a liquid separator on the inlet side. Advantageously, the compressor 4 has a particularly efficient two-stage oil separator on the outlet side.
[0020] Preferably, the compressor 4 compresses the outgoing carbon dioxide at a pressure comprised between 25 and 28 bar.
[0021] The collection and recovery system 3 comprises a storage means 6 for storing the carbon dioxide coming from the compressor 4. The storage means 6 may comprise a pressure vessel, for example a pressurized cylinder. The storage means 6 is a means for storing liquid carbon dioxide, in particular under a pressure between 17 and 25 bar, preferably between 17 and 22 bar, advantageously between 18 and 20 bar. The carbon dioxide can thus be recovered (advantageously in liquid form) for subsequent reuse in the system for producing dry ice.
[0022] The collection and recovery system 3 comprises a heat exchanger 5 that puts the carbon dioxide downstream of the compressor 4 in thermal communication with the carbon dioxide upstream of the compressor 4. In particular, the heat exchanger 5 puts the carbon dioxide immediately downstream of the compressor 4 in thermal communication with the carbon dioxide upstream of the compressor 4. Advantageously, the exchanger 5 is a plate exchanger, preferably a cross-flow plate exchanger. The thermal communication makes it possible to reduce the temperature of the gaseous carbon dioxide before it enters the compressor from a temperature range between -70°C and -78.5°C to around a temperature comprised between -40°C and -45°C in order to liquefy the carbon dioxide in the positive displacement piston compressor. The presence of said thermal communication optimizes the functioning of the positive displacement piston compressor and saves energy.
[0023] Advantageously, the collection system 3 comprises a line 30 for the flow of the carbon dioxide collected downstream of the means 20 to the storage means 6. This flow line 30 advantageously comprises: - a first section 31 upstream of the heat exchanger 5; a second section 32 extending from the exchanger 5 downstream of the intermediate outlet 320 to the exchanger 5 upstream of the intermediate inlet 321 (the compressor 4 is arranged along the second section 32); - a third section 33 downstream of the exchanger 5 Equipped with.
[0024] Conveniently, between the exchanger 5 and the compressor 4 (in the second section 32), the gaseous carbon dioxide is at a temperature comprised between −45° C. and −40° C., between the compressor 4 and the exchanger 5 (in the second section 32), the liquefied carbon dioxide is at a temperature comprised between 15°C and 20°C, Immediately downstream of the exchanger 5 (in the third section 33), the liquid carbon dioxide is at a temperature comprised between -10°C and -40°C, preferably between -25°C and -30°C.
[0025] The first section 31, the second section 32 and the third section 33 define the same channel. They are arranged in consecutive order.
[0026] The carbon dioxide in the first section 31 is used to cool the carbon dioxide in the third section 33 .
[0027] In this description, the expressions "upstream of" and "downstream of" should be understood to refer to the direction of carbon dioxide flow.
[0028] Upstream of the compressor 4, the system 3 may comprise a safety valve 41 (the safety valve 41 is advantageously arranged upstream of the compressor 4 and downstream of at least a part of the exchanger 5; the safety valve 41 is advantageously arranged in the second section 32). The safety valve 41 allows bypass of the compressor 4 or release of carbon dioxide. The safety valve 41 may be a motorized valve.
[0029] Advantageously, the carbon dioxide immediately upstream of the exchanger 5 (in the first section 31) is at about 1 bar and advantageously at a temperature below -76.8°C, for example at a temperature of -78.5°C, in practice between -70°C and -78.5°C. Advantageously, the carbon dioxide immediately downstream of the compressor 4 (in the second section 31) is at about 1 bar and advantageously at a temperature below -76.8°C, for example at a temperature of -78.5°C, in practice between -70°C and -78.5°C. 2 The liquid carbon dioxide (in the first section 31) is at a pressure comprised between 25 bar and 28 bar and at a temperature comprised between 15° C. and 20° C. Advantageously, immediately upstream of the heat exchanger 5 (for example in the first section 31), a 300 m 3 / h to 500m 3 / h, preferably about 400 m 3 Advantageously, immediately upstream of the heat exchanger 5, there is a carbon dioxide flow rate comprised between 700 kg / h and 900 kg / h, preferably around 800 kg / h.
[0030] Advantageously, the system 3 comprises a check valve 60 interposed between the compressor 4 and the storage means 6 (for example in the third section 33).
[0031] This prevents / limits the return of carbon dioxide present in the storage means 6 .
[0032] A safety valve 61 may be present between the compressor 4 and the check valve 60 (e.g., in the third section 33). The safety valve 61 allows bypass of the valve 60 or release of carbon dioxide. The safety valve 61 may be a motorized valve.
[0033] In certain solutions, the system 3 can optionally comprise a homogenizer 7. Advantageously, the homogenizer 7 is arranged between the compressor 4 and the storage means 6 (typically in the third section 33).
[0034] The homogenizer 7 makes it possible, for example, to compress carbon dioxide at pressures also above 100 bar, advantageously also comprised between 200 and 250 bar. In this way, storage can take place in the means 6 at higher pressures. Downstream of the homogenizer the temperature is between -20°C and -25°C.
[0035] Advantageously, the system 3 may be equipped with one or more temperature sensors 81, for example in the solution of FIG. 2 one temperature sensor is present in the first section 31, two temperature sensors in the second section 32 (one upstream of the compressor 4 and one downstream of the compressor 4) and one temperature sensor in the third section 33.
[0036] Advantageously, the system 3 may comprise several electric heaters (not shown) arranged in the first section 31 between the heat exchanger 5 and the compressor 4. If the temperature of the gaseous carbon dioxide is too low while entering the compressor 4, the electric heaters regulate the temperature to the range of -40°C to -45°C.
[0037] Advantageously, the system 3 may comprise one or more pressure sensors 82 (for example in the solution of FIG. 2 the pressure sensor 82 is placed downstream of a part of the exchanger 5 and upstream of the compressor 4). The pressure measurement by this particular sensor is about 5 bar.
[0038] The subject of the present invention relates to a method for producing dry ice. In particular, it is a method for producing dry ice that envisages at least partial recovery of carbon dioxide that is not converted into dry ice. More generally, it can also be defined as an apparatus for handling liquid carbon dioxide. Advantageously, this method is carried out by an apparatus 1 for producing dry ice that has one or more of the characteristics previously described.
[0039] The method comprises a step of solidifying (liquid) carbon dioxide, thus obtaining dry ice, which is typically obtained in a state transition means 20 (typically a squeeze means).
[0040] The state transition means 20 provides the desired solidification of carbon dioxide to produce dry ice, and the undesirable formation of carbon dioxide in a gaseous state.
[0041] Thus, the transition of the carbon dioxide from the liquid state to the solid state takes place, which is obtained by expanding the carbon dioxide in the throttling means.
[0042] The method also includes collecting the gaseous carbon dioxide downstream of the state transition means 20.
[0043] The method also includes compressing the carbon dioxide in gaseous state by a compressor 4, thereby converting the gaseous carbon dioxide into liquid carbon dioxide.
[0044] The method comprises the step of storing said liquid carbon dioxide in a storage means 6 .
[0045] Advantageously, the method may comprise a step of carrying out a heat exchange between the carbon dioxide present downstream of the compressor 4, which in practice has a temperature between 15° C. and 20° C., and the carbon dioxide present upstream of the compressor 4, which in practice has a temperature between −70° C. and −78.5° C. Advantageously, this heat exchange is carried out in a heat exchanger 5. The carbon dioxide present downstream of the compressor 4 and the carbon dioxide present upstream of the compressor 4, which are in thermal communication via the heat exchanger 5, flow along the same conveying line. This allows the carbon dioxide present downstream of the compressor 4 to be cooled by the carbon dioxide present upstream of the compressor 4. This arrangement in combination with a positive displacement piston pump saves energy.
[0046] The present invention achieves important advantages.
[0047] Firstly, the present invention allows for the recovery of volatile carbon dioxide in the production of dry ice, thereby reducing raw material consumption and energy consumption.
[0048] The invention thus conceived is susceptible to many modifications and variations, all of which are within the scope of the inventive concept which characterizes it. Moreover, all details can be replaced by technically equivalent elements. All materials and dimensions used can in fact be according to need, whatever the case may be. [Explanation of symbols]
[0049] 1 device 2 Supply means 3. Collection and Recovery System 4. Compressor 5 Heat exchanger 6 Storage Means 7 Homogenizer 20 State Transition Method 21 Tank 22 Conveyor Line 23 Collection Tank 30 Flow Line 31 First Section 32 Second Section 33 Third Section 41 Safety valve 60 Check valve 61 Safety valve 81 Temperature Sensor 82 Pressure Sensor 320 Intermediate exit 321 Middle Entrance
Claims
1. A supply means (2) for supplying carbon dioxide in liquid form; a means (20) for transition of at least a portion of the carbon dioxide flowing along the supply means (2) from the liquid state to a solid state, the state transition means (20) providing the desired solidification of the carbon dioxide to produce dry ice and the undesired formation of gaseous carbon dioxide; a system (3) for collection and recovery of the gaseous carbon dioxide, the collection and recovery system (3) collecting the gaseous carbon dioxide downstream of the state transition means (20); i) a compressor (4) for compressing the carbon dioxide collected downstream of the state transition means (20); ii) a storage means (6) for storing the carbon dioxide coming from the compressor (4); A system (3) comprising: An apparatus for producing dry ice, comprising: said compressor (4) being a positive displacement piston compressor capable of compressing the exiting carbon dioxide at a pressure comprised between 25 bar and 28 bar; the collection and recovery system (3) comprising a heat exchanger (5) in thermal communication with the carbon dioxide downstream of the compressor (4) and the carbon dioxide upstream of the compressor (4); said storage means (6) being means for storing liquid carbon dioxide under a pressure between 18 and 20 bar; An apparatus comprising:
2. 2. Apparatus according to claim 1, characterized in that the exchanger (5) is a plate exchanger.
3. The system (3) for collecting and recovering carbon dioxide comprises a line (30) for the flow of the carbon dioxide collected downstream of the means (20) to the storage means (6), the flow line (30) comprising: a first section (31) upstream of the heat exchanger (5); a second section (32) extending from said exchanger (5) downstream of an intermediate outlet (320) to said exchanger (5) upstream of an intermediate inlet (321); a third section (33) downstream of said exchanger (5); The device according to claim 1, characterized in that it comprises:
4. 4. The apparatus according to claim 3, characterized in that the system (3) for collection and recovery of carbon dioxide further comprises an electric heater arranged in the first section (31) between the exchanger (5) and the compressor (4).
5. 2. Apparatus according to claim 1, characterized in that the collection and recovery system (3) comprises a check valve (60) interposed between the compressor (4) and the storage means (6).
6. 2. Apparatus according to claim 1, characterized in that the collection and recovery system (3) comprises a homogenizer (7) arranged between the compressor (4) and the storage means (6).
7. freezing at least a portion of the liquid carbon dioxide, thus obtaining dry ice, via a state transition means (20), said state transition means (20) providing the desired freezing of said carbon dioxide to produce dry ice, and the undesired formation of gaseous carbon dioxide; collecting the gaseous carbon dioxide downstream of the state transition means (20); compressing the carbon dioxide in gaseous state by a compressor (4) having the form of a positive displacement piston compressor compressing the exiting carbon dioxide at a pressure comprised between 25 bar and 28 bar, thereby converting the gaseous carbon dioxide into liquid carbon dioxide; storing said liquid carbon dioxide in a storage means (6) under a pressure between 18 and 20 bar; carrying out a heat exchange between the liquid carbon dioxide present downstream of the compressor (4) having a temperature between 15°C and 20°C and the gaseous carbon dioxide present upstream of the compressor having a temperature between -70°C and -78.5°C; 1. A method for producing dry ice, comprising: