JPS6325801B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is useful in the food industry, especially in beer production.
In a liquid condensation process carried out under normal pressure and heat supply, the vapor evaporated in the condensation process is initially compressed as adiabatically as possible and then condensed by isobaric cooling, condensing the heat liberated during condensation. This invention relates to a method and apparatus for reusing the process. In brewery operations, excess heat is generally present at temperature levels below 100°C. This is primarily associated with the various waste heat sources of brewery operations. Such heat sources include: - pre-cooling chambers of plate units for wort cooling; - steam condensers when boiling maicier and wort; - in condensate economy during steam feeding operations. Post-evaporation steam - preheaters in direct heating boiling machines All these waste heat sources are conventionally used exclusively for hot water production. The supply of hot brewing water at approximately 80° C. is currently carried out almost exclusively by hot water withdrawn from the precooling chamber of the plate device for cooling the wort. This hot water has a very good match in terms of volume and temperature: 1.1 hl of 80°C hot water per 1 hl of germinated wort. On the other hand, the demand for hot water in other operations (keg washing equipment, sanitary equipment, water for sterilization, etc.) varies within a wide range, and the majority of all operations have
Approximately 0.5hl per 1hl. However, with only one steam condensing installation, approximately 0.8 hl of hot water can be recovered per hl of beer sold, so this already leaves one waste heat source in excess. This fact means that according to the Federal Environmental Protection Law, during boiling and wort boiling, the evaporated steam is accompanied by the release of a bad odor, so it must be made odorless, and on the other hand, hot water with a temperature of 35°C or higher must be made odorless. The discharge of wastewater is also a problem because it is not allowed according to wastewater legislation. The evaporated steam can also be used for boilers in absorption refrigeration equipment. The costs for this are so great that no economy can be achieved. The use of heat pump equipment is dependent on the required temperature level.
140°C, for which it has hitherto been excluded because no suitable refrigerant is available. It is therefore an object of the invention to find another way in which the steam that evaporates during maisher boiling and/or wort boiling can be utilized in order to feed the energy content of this steam back into the brewing process. It is. This problem is solved according to the invention when the method is used in Maisier boiling and/or wort boiling in a brewery, in which the compressed steam is passed through an external boiler in which the wort is liberated by the condensation heat. The solution was to use the condensate to generate live steam which was then fed to an external boiler. This method results in a considerable reduction in the primary energy demand during maisher boiling and/or wort boiling, and furthermore, the odor emission that previously occurred during maisher boiling and/or wort boiling is completely prevented. has advantages. The work required for compression is advantageously carried out using an internal combustion engine, the waste heat of which can be used for hot water production, thereby further reducing the primary energy demand. For the same purpose, the heat contained in the condensate can also be used for hot water production. Instead of an internal combustion engine, an electric motor can be used because of its low energy demand if the demand for hot water is low and therefore the waste heat of the internal combustion engine cannot be utilized. Furthermore, in order to optimize the use of the energy contained in the evaporated steam, it is advantageous to mix condensate with the compressed steam to cool it from a superheated state to the saturated steam temperature. However, in terms of efficiency, it is advantageous to mix the vapor with condensate immediately upon compression. The apparatus for carrying out the method of the invention consists of a wort kettle and a compression pump for self-steaming, the compression pump being a screw compressor, the wort kettle being equipped with an external boiler, and the boiler being equipped with a screw compressor. is upstream and a condensate collection tank is downstream, the condensate being available for the generation of live steam, which live steam can then be fed to an external boiler. With this device, difficulties that can arise if the steam is admixed with large amounts of air or contaminated by foreign matter are avoided. This is because, on the one hand, external boilers can boil the wort with the dome manhole closed, so there is only a small amount of air in the steam to begin with, and on the other hand, the screw compressor allows boiling the wort with the manhole closed, so there is only a small amount of air in the steam to begin with. This is because small amounts of impurities in the steam can be removed. External boilers also have the advantage that they can be easily cleaned if necessary. A diesel engine is advantageously provided for driving the screw compressor, since its efficiency is very high and is therefore much superior to gas engines and gas turbines. The heat contained in the condensate as well as the waste heat of the diesel engine can be used to produce hot water. Therefore, the external boiler is preferably followed by a heat exchanger, in which heat is extracted from the condensate and fed to the industrial water. Additionally or alternatively, the diesel engine is connected to a heat exchanger in which the waste heat of the diesel engine is used for hot water production. If both systems are used for the production of hot water, the first heat exchanger is advantageously connected in series with the second heat exchanger, so that the industrial water is not contained in the condensate. It is preheated with heat from the diesel engine and brought to its final temperature with waste heat from the diesel engine. The screw compressor can also be driven using an electric motor. The external boiler is preferably adjoined by a steam cooler, to which condensate from the external boiler can be fed for injection into the compressed steam. As an alternative to the steam cooler, the screw compressor may be configured such that condensate from an external boiler can be supplied to it for injection into the steam during compression. The application of the method of the invention and the device for carrying out the method is not limited to the production of beer, but can generally be carried out in all concentration steps in the foodstuff industry. Excellent scope of application exists in dairy farming as well as beer production. The wort W is transferred from the wort pot 1 to the external boiler 2 in the direction of the arrow.
After passing through the external boiler 2,
It is returned to wort pot 1 again. First, the wort in the external boiler 2 is heated to boiling temperature using live steam F supplied from a steam boiler (not shown). As soon as sufficient self-steam BD has been generated in the wort kettle 1, this steam is compressed adiabatically in a screw compressor 3 and fed via a steam cooler 4 to an external boiler 2, where it transfers heat to the wort. Add to juice W and condense.
The heating of the wort W in the external boiler 2 takes place entirely by supplying the heat of condensation and no longer by live steam FD. The screw compressor 3 is driven by a diesel engine 5, whose cooling water and waste heat from the flue gas RG are used in a heat exchanger 6 to heat industrial water BW. The condensate K produced in the external boiler 2 is fed to a heat exchanger 7 and/or a condensate collection tank 8 .
In the heat exchanger 7, the heat contained in the condensate is used to preheat the industrial water BW, which is then fed to the heat exchanger 6, where it is heated to the final temperature. If necessary, condensate from the condensate collection tank 8 is fed to a steam cooler in which it is injected into the compressed steam in order to cool it to saturation temperature. The amount of condensed liquid supplied to the condensed liquid collection tank 8 and the heat exchanger 7 is controlled by a liquid amount regulator 9. The amount of condensate entering the steam cooler is controlled by a temperature controlled valve 10. Instead of a steam cooler, a screw compressor is provided in which the condensate from the condensate collection tank 8 is compressed, as represented by the dashed line from the condensate collection tank 8 to the compressor 3. It may be configured such that it can be supplied for injection into steam during a process. Furthermore, if for some reason the external boiler 2 has to be additionally supplied with live steam FD, the condensate can also be used for live steam production (double dashed line). Calculation example 1 Heat consumed per hour during wort boiling (heat of condensation) Concentration power of external boiler 11% Germinated wort volume 100hl/hr Heat of evaporation at 1013 mbar: 2255.5KJ/
Kg Density of water at 100℃: 0.958Kg / Heating surface efficiency 0.87-0.93 (depending on the quality of the insulation material) Hourly heat consumption (heat of condensation) during wort boiling, calculated as follows based on these values: : 11hl/h.100/hl・2255.5KJ/Kg・0.958Kg／／
0.87 (0.93) = 2732 (2556) MJ/h Equivalent to 758.9 (709.9) KW 2 Hourly fuel consumption when boiling wort using a steam boiler Boiler efficiency 82% Density of ultra-light fuel oil = 0.83 Kg/ ultra-light Low value calorific value of fuel oil 42.7MJ/Kg Hourly fuel consumption is calculated as follows: 2732 (2556) MJ/h/42.7MJ/Kg・0.83Kg/・0.
82=94.00 (87.95・1/100hl) 3 Power demand for vapor compression The power demand for the screw compressor shaft is:
Calculated depending on various heating vapor pressures. Already boilers are used with a heating steam pressure of 2.5 bar,
For external heating surfaces, a pressure of 2 bar is sufficient, but for completeness a heating steam pressure of up to 4 bar is nevertheless included. The basis of the calculation is the diagram of the screw compressor shown in Figure 2, in which a real total efficiency of 65% (=quality class x mechanical efficiency) is taken into account. In this diagram, the power of the heat pump ε _Wp [KJ/KJ]
is plotted as a function of various pressure differences (as temperature differences). The power for various heating vapor pressures is estimated as follows:

[Table] After knowing that the heat of condensation at the heating surface is 709.9~758.9KW, the power demand for vapor compression is calculated as follows:

[Table] 4 Calculation of heating vapor pressure in equilibrium state The vapor evaporated during wort boiling is directly related to the amount of heat of condensation at the heating bottom, so at the specific heating vapor pressure to be confirmed, An equilibrium condition occurs where the indicated compressor power is just sufficient to cover the heat losses. 11hl evaporates per hour, resulting in a heat of vaporization of 2255.5KJ/Kg (at 1013 mbar) and 0.958Kg/(100℃)
Starting from the hourly heat of vaporization at the density of water at ) is calculated: 11hl/h・100/hl・2255.5KJ/Kg・0.958Kg/=23
76846KJ/h=660.23KW The mechanical efficiency of the screw is considered to be 90% considering the partial load behavior. The indicated compressor power and condensing power (actual and target) are now calculated.

[Tables] It is clear from these tables that at a heating vapor pressure of 2 to 3 bar an equilibrium situation occurs between condensing power, evaporation power and indicated compressor power.
Within this pressure range, the heat balance of the heat pump is satisfied. However, a heating surface efficiency of only 87% (lower limit value) occurs only in practically uninsulated heating surfaces, so that in practice heating steam pressures of 2.0 to 2.5 bar are set. 5 Fuel consumption for diesel to drive the screw The efficiency of the diesel to drive the screw is stated to be 39%. Considering the part load behavior, an average efficiency of 35% should be used as a starting point for the following calculations.

【table】

[Table] 6 Economy of steam compression equipment The heating vapor pressure is necessarily 2.0 to 2.5 bar, and this vapor pressure is certainly sufficient for the engineeringly necessary concentration power in the case of an external boiler, so With such a steam compression device, savings of 73% to 80% can be obtained during wort boiling. Furthermore, it must be taken into account that such a device simultaneously makes it possible to comply with 100% of the Federal Environmental Protection Laws and that neither steam nor odorants are released into the environment. 7 Waste heat utilization The steam evaporated during boiling and wort boiling often covers the demand for hot industrial water in breweries using so-called kettle steam condensers. This demand varies between 0.3 and 0.5 hl per hl of beer for most of all breweries. Incidentally, the waste heat of the diesel engine as well as the boiling condensate flowing in the drain pipes are also utilized for the production of hot industrial water. Heat exchanger 7 can cool the condensate to 60℃ (h _k
=250.91KJ/Kg). Diesel waste gas can be utilized for 50% hot water production. The following table provides an explanation of waste heat utilization.

[Table] 29269 MJ is required to make 1 liter of 80°C hot water from 10°C cold water. Boiling time of wort
It takes 90 minutes, and the loss from wort (AW) to commercial beer (VB) is 10%. Therefore, the following amount of hot water can be produced from waste heat:

[Table] As is clear from the table, the hot water demands of brewery operations can be covered (almost) 100% in all cases, so that by using diesel-operated steam pressure equipment the primary water supply in the wort boiling process is Energy demand will be reduced by approximately 73-80%. Therefore, by using such a device an ideal heat balance can be achieved. It is almost impossible to think of any advantageous use of heat.

[Brief explanation of the drawing]

Figure 1 is a system diagram showing one embodiment of the present invention for beer production, and Figure 2 is the temperature difference/power between the condensing temperature and evaporation temperature of the hydrothermal pump for the screw compressor used in the calculation example. It is a curve diagram. 1...wort pot, 2...external boiler, 3...screw compressor, 4...steam cooler, 5...diesel engine, 6, 7...heat exchanger, 8...condensate collection liquid Tank, B...wort, BW...industrial water, FD...
...live steam.

Claims (1)

[Claims] 1. In order to recover energy in the liquid condensation process in the food industry, which is carried out under atmospheric pressure and heat supply, the vapor evaporated in the condensation process is first compressed as adiabatically as possible and then is A method in which condensation is carried out by pressure cooling and the heat liberated during condensation is reused in the condensation process, when the method is used in Maisier boiling and/or wort boiling in breweries, the compressed vapor is atmospheric pressure and characterized in that the wort W is heated by the heat of condensation liberated in the external boiler, and the condensate K is used to generate live steam FD which is supplied to the external boiler. A method for recovering energy in a liquid concentration process in the food industry, which is carried out under heat supply. 2. A steam cooler is provided in front of the external boiler, and the condensate K from the external boiler is supplied to the cooler for injection into the compressed steam.
The method described in section. 3. Process according to claim 1 or 2, in which the condensate K from the external boiler is fed for spraying into the steam mist during compression. 4 Consists of a wort pot and a self-steam compression pump, the compression pump is a screw compressor 3, the wort pot 1 is equipped with an external boiler 2, and the boiler is adjacent to the screw compressor 3, and A condensate collection tank 8 is arranged afterwards, and the condensate can be used for live steam generation.
Device for recovering energy in liquid condensation processes in the food industry, which are carried out under atmospheric pressure and heat supply, characterized in that this live steam FD can then be fed to an external boiler 2.