WO2006087030A1

WO2006087030A1 - Ice producing method and device

Info

Publication number: WO2006087030A1
Application number: PCT/EP2005/013843
Authority: WO
Inventors: Otto-Wilhelm Held
Original assignee: Otto-Wilhelm Held
Priority date: 2005-02-21
Filing date: 2005-12-22
Publication date: 2006-08-24
Also published as: DE102005008145B3; EP1869376A1

Abstract

The invention relates to a device for producing ice, in particular for construction purposes, wherein an ice machine (1) comprises an upholstered heat pump (11) provided with an ammonia circuit, the condenser (12) of said machine is cooled by air and spaying water and an evaporator (14) is continuously supplied with water which; after being transformed into ice, falls in an ice container (2) which is lower arranged and provided with a demand-controlled discharge device (21), the evaporator (14) operates at approximately 11 °C and the ice produced thereon is detached by periodical coolant vapour bumps in such a way that the humid ice falls in the ice container (2) which is provided with the discharge device (21) arranged on the bottom thereof. The uncontrolled evaporator (14) is used for producing cold water stored in a cold-water tank (3). Trickling water is introduced at different rates into the condenser (12) for producing and separating ice.

Description

Method and device for ice making

The invention relates to a method and an apparatus for ice cream production, in particular for construction purposes, in which an ice machine with a heat pump with an ammonia circuit is arranged elevated, the condenser of which is cooled by air and water spray and the evaporator of which water is continuously fed, which is frozen into ice at a lower level Ice container falls.

Devices of this type are used in particular in warm climates for construction purposes with high ice output, since concrete is predominantly mixed with ice instead of water so that it sets slowly and thus achieves the required density and strength. In order to cover the daily requirement for ice, which occurs sporadically at daytime, the ice machine arranged on an upper floor is often in operation day and night, the ice of which is stored in the container on a lower floor. Night operation is more economical because the cooling air of the condenser is then much lower than during the day. The known devices have a freezer, which is operated at about -22 ⁰ C Evaporation temperature so that is oversprayed water freezes to ice immediately, the sub-cooled to about -7 ⁰ C grain falls into the container. The low freezer temperature leads to a low efficiency of the heat pump. In addition, the supercooled ice grains tend to clump, as atmospheric moisture condenses and freezes on them, causing the grains to grow together. Therefore, the discharge device is a scraper conveyor located on top of the ice stock, but it is leaves a highly compacted layer of ground ice that gradually grows and has to be chopped out periodically in a very complex manner.

Furthermore, ice machines are known which are used in the food industry are used, the plate evaporator is operated at about -11 ⁰ C, whereby wet ice from forming in a constant dose of above supplied sprinkled. This is thawed from the evaporator surface at short intervals with a blast of coolant vapor blown into the evaporator, so that it detaches in the form of a shard and, after slipping, falls over an inclined sieve plate into an ice container.

It is an object of the invention to improve the device for making ice for construction purposes in terms of efficiency and usability and to disclose an effective method for making ice which can be used in general.

The solution is that the evaporator is operated at about -11 ⁰ C and to it resulting from sprinkled ice replaced by periodic refrigerant vapor poking wet, fall within the Eiscontainer, the extraction device is arranged on the bottom side therein.

An improved process results in accelerated defrosting due to the increased application of trickle water during the defrosting times compared to the ice formation phases.

Advantageous refinements are specified in the subclaims.

The evaporator temperature, which is considerably higher than that of the known device, results in a significantly higher efficiency of the heat pump. The damp ones remain Chunks of ice, the temperature of which is approx. -3 ° C, are constantly slidable, which makes it possible to arrange the conveyor at the bottom of the ice container, so that the entire storage space and ice supply is always available and there is no need to break out of blocked ice.

A further increase in efficiency is achieved by the use of the knowledge that the incidental by Sprühwasserverdunstung in the air flow of the condenser unverdunstete water undergoes a cooling of about 1O ⁰ C. This thus pre-cooled water is fed to the evaporator as trickle water, so that its ice formation capacity is increased.

Furthermore, at least one water tank is advantageously arranged on the lower floor, in which whenever z. B. in construction, a sufficient ice supply for an upcoming concreting process is created in the ice container, with the evaporator cooled trickle water is generated, it being operated at an evaporator temperature of approx. -3 ° C. This water cooling takes place with a comparatively very high efficiency of the heat pump. The water, which is cooled to approx. 1 ° C in one step and then stored, is used for mixing concrete, as is the separately stored ice, so that less ice is used.

By reversing the operating pressure and thus the evaporation temperature, the same cooling system is used for ice and cooling water production; a separate water cooling device is not required.

Overall, these measures alone may result in the new device on average to an energy saving of about 30% when the daily temperature is 50 ^0C.

The overall device is advantageously modularly constructed in a container block construction, so that individual ice machine containers, ice containers and cooling water containers can be supplemented or exchanged in each case. For example, there is an ice container and any number of water containers on the lower floor of a rack. A maximum of four of the ice machine containers are arranged on supports across the lower containers on the upper floor, with the evaporator standing above the ice container. In this way, the overall performance of the respective construction site requirements and the climatic conditions can be optimally adapted by selecting a different number and type of modules. Relocation to other construction sites, including individual modules, is possible without any problems, since only a few connections, namely for water, for control cables and for electricity, have to be made to them. The containers are manufactured at the factory so that a construction site can be equipped without individual planning.

On the discharge side, the ice falls into a cyclical cross conveyor, so that no connection work is necessary there either. The presence of multiple units not only increases the total available output, but also the availability in the event of maintenance or repair work.

The cyclic cross conveyor is advantageously followed by an inclined conveyor, which opens into an ice weigher, which consists of a vertical storage container with a bottom lock under which the metered ice is evenly distributed on a conveyor belt, for example, of an external concrete system.

Parts of the ice machine are advantageously designed redundantly. Two fan-condenser units and two evaporator ice-makers are arranged next to each other and connected by their own coolant lines, which, however, are each connected to a compressor and a condensate collector. In the event of faults in a double unit, operation with reduced power can continue with only one unit. Another significant energy saving of approx. 10% is achieved by a new type of control method for sprinkling the evaporator, with the sprinkling amount taking place during the ice formation phases with a small excess of the amount of ice formed, so that the cooling energy supplied by the evaporator is only a small part of the flowing trickle water into one Recirculating trickle water supply is taken over, and the amount of de-icing sprinkling is increased considerably, which results in a much faster detachment of the ice shards from the evaporator surface and, accordingly, the introduction of steam into the evaporator is shortened and the next ice formation phase begins earlier.

It has been shown that the increased de-icing sprinkling leads to a rapid thawing of the ice in the area of impact of the water threads, so that the water soon spreads like a wedge between the evaporator surface and the ice shard and causes it to slide down quickly as a whole. This shortens the entire period of icing and de-icing by 5 - 10%, which results in an efficiency increase of around 10%.

A particularly simple way of controlling the

Trickle speed can also be set up by retrofitting ice machines, such as those already used in the food industry, by adjusting the level of the trickle water supply in an overhead trickle pan to different levels so that it runs out of the bottom-side passage openings and at the appropriate speed occurs on the evaporator plates or ice that has already formed and is distributed there.

To change the level of the trickle water supply, the water circulation pump is advantageous during the de-icing phase or in advance somewhat with an increased, e.g. B. operated at double speed and thereby additionally trickle water from the water collection tank into the trickle tank. In a simple embodiment of the control device, overflows at a corresponding height on the trickle trough, which lead back into the water collection trough and of which the lower one is blocked by a valve during the defrosting phase, are advantageously used to precisely maintain the two levels. A delayed opening of the valve and therefore a slow lowering of the level at the beginning of the icing phase contributes to the sinking

Ice formation speed with increasing ice thickness calculation, so that the delivered cooling energy is optimally used for ice formation.

In another embodiment, the sprinkling speed controls a control device with a level sensor, an ice thickness meter and a frequency-controlled water circulation pump, with which the level is continuously adapted to the ice formation rate.

Advantageous configurations are shown in FIGS. 1 to 7.

FIG. 1 shows a transparent perspective view of an overall system with multiple modules;

Figure 2 shows a perspective view of an ice machine;

Figure 3 shows an end view of Figure 1;

Figure 4 shows a rear view of Figure 1;

FIG. 5 shows a symbolized axial section through an ice scale;

FIG. 6 shows a transparent end view of an ice scale;

Figure 7 shows a block diagram of the media flows.

Figure 1 shows two ice machines 1 in two

Ice machine containers 40 are housed. These containers 40 are arranged on container support structures 4 above water tank containers 30 mounted on the bottom, each of which encloses a cold water tank 3, and an ice container 2. The ice machine consists of the compressor 11, which is driven by the motor 10. The compressed coolant is cooled in the condenser 12 by the spray water evaporator 13 by an air flow. The condensate is collected in the separator 43 and fed to the evaporator 14 via a throttle. This is provided with water sprinkling in a cycle. The periodically dissolved ice is discharged via a sieve plate 15 through the chute 20 of the ice container 2, the excess cold water would be collected under the inclined sieve 15 in a tub 16 and pumped around again.

As an alternative, cooled water is generated at a higher evaporator temperature and flows from the tub 16 into one of the water tanks 3 is directed. From there it is conducted to the place of consumption via a cold water drain 32.

At the bottom in the ice container 2 there are four screw conveyors 21 in a parallel arrangement. On the discharge side of these, a transverse conveyor 23 is arranged underneath, from which an inclined conveyor 49 leads into an ice scale 5. This consists of a slightly diverging shaft 50, which is arranged in a frame and has a lock 51 on the bottom, which is actuated by a lock motor 52 as required.

A fitting cabinet 53 is mounted on the side for the control device. In the fan-Verdunster 13 a water collecting trough is arranged on the bottom side of said cooled by evaporation cooling to about 10 ⁰ C fresh water with a chilled water pump 54 in the Berieseier of the evaporator is conveyed fourteenth From there, the in the collecting tray 16 collected nearly 0 ⁰ C cold water with the circulation pump 17 back to the Berieseier the evaporator fed or reversed into the water tank 3 derived.

Further details can be seen in FIG. 2.

The containers 2, 3 are each covered with a heat insulation layer 42.

Figure 3 shows an end view of the overall arrangement. A staircase 55 with an inspection ramp 56 leads to the ice machine container 40. From there, the fitting cabinet 53 is accessible, through which the coolant lines lead. A control valve block 18 is connected upstream of the evaporator 14, so that the liquid coolant and, reversed, the coolant vapor can be fed to the evaporator and, accordingly, the return line is opened accordingly.

From the water pan 16, a suction line leads to the circulation pump 17, which is followed by a valve 41, which is either a Circulation or a derivation in the cold water inlet 31 of the cold water tank 3.

There are several at the bottom in the ice container 2

Conveyor screw drives 22 are arranged by connected symbolically represented conveyor screws 21. The screw 24 of the cross conveyor 23 leads to the inclined conveyor 49 and this ends above the shaft 50 of the ice scale 5.

Figure 4 shows further details from the rear of the system. The conveyor screws 21 end above the cross conveyor 23, which is formed with a trough-like housing in which a screw conveys. Through the inclined conveyor 49, the ice comes into the ice scales 5, which are suspended in a support frame 58 with scale supports 57.

Details of the ice scales 5 can be seen from FIGS. 5 and 6. The shaft 50 diverges slightly downwards so that no ice can get stuck. The lock is equipped with radial toothed plates which are rotatably mounted on two parallel axes and which, if two of them are transverse, provide a seal, otherwise open a cell space downwards.

Figure 7 shows a block diagram, in particular the coolant and trickle water.

The compressor 11 usually drives the compressed coolant vapor through a steam line D into the condensers 12A, 12B, which are each connected to the water line W by water sprays via controlled valves. The fan 13A, 13B blows against the spray water. Residual pre-cooled spray water is collected and discharged by the pump 54 and fed to the trickling tanks above the evaporators 14A, 14B, below which the drained water is collected in the tanks 16A, 16B and returned by the water pump 17 or alternatively is passed through the reversing valve 41 to the cold water connection 31 of the water tank.

The cooled refrigerant coming from the heat exchangers, the condensers 12A, 12B, is passed into the separator 43. A condensate line K leads from the separator 43 to the valve blocks 18A, 18B. There, with individually controllable valves VIl - V14, an ice formation state and an ice release state can be controlled by either switching through the steam line D or a condensate line K coming from the bottom of the separator 43, the output leading in each case with a return line R to the separator 43, from where the compressor 11 sucks the gaseous coolant. An adjustable expansion valve EV is arranged upstream of the evaporators 14A, 14B. A pressure meter or pressure switch P is used to set the operating pressure and thus the operating temperature.

Shut-off valves V21 - V24 are provided on the supply and discharge lines for decommissioning the capacitors 12A, 12B; valves VIl - V14 must also be completely blocked during repair and maintenance work. The double condensers 12A, 12B and the evaporators 14A, 14B can be operated completely independently by means of double valve arrangements. However, it is expedient to carry out the operation in parallel for ice production at a low temperature of the evaporators 14A, 14B or for cold water production at a higher temperature of the evaporators.

For the effective operation of ice production, trickling tanks 19A, 19B are arranged above the evaporators 14A, 14B, from which thin water threads run onto the upper edge of the evaporator plates, from where the trickling water is distributed evenly over the evaporator plates or ice placed thereon. The level of the pent-up trickle water supply in the trickle tanks 19A, 19B is in each case between a lower level N1 and changed to a higher level N2 by changing the output of the water pump 17 in a controlled manner, the level N1 being expediently limited by an overflow valve V15. As an alternative or in addition, a level sensor NS is arranged in each of the trickle trays 19A, 19B, the signal of which is evaluated in a control device CTR, which is used to control the speed of the water pump 17, as a result of which the optimum level and thus the trickle rate of the trickle water is determined. This control device CTR also suitably controls the reversing valves VIl-V14, which control the ice formation phase and the deicing phase. During the former there is a low trickle water level. Nl and while the latter is driven to a higher level N2.

The phase reversal between ice formation and ice removal takes place in the simplest manner by means of time signals from a clock generator CL, which are fed to the control device CTR. In a further development of the method, the phases are reversed as a function of the ice thickness, for which the signal from an ice thickness sensor IS is used.

A flow rate of the water which is quite precisely adapted to the ice formation rate during the ice formation phase is advantageously controlled by means of the signal from the ice thickness sensor IS, which is fed to the control device CTR. With its control signal FC, this controls, for example, a frequency generator FG which controls the speed of the water pump 17.

Since the level changes due to the filling or draining of the trickle water each take place with a delay, the control device CTR is preferably provided with an inverse PID characteristic for frequency control and / or with a lead and a lag with respect to the valve reversal. In application of all vorbeschriebener advantageous method measures an energy saving of about 60% is achieved to the previously known systems at an ambient temperature of about 5O ⁰ C.

Reference list

1 ice machine

10 engine

11 compressor

12, 12A, 12B capacitor

13, 13A, 13B fan evaporator

14, 14A, 14B evaporator 15 screen plate

16, 16A, 16B water collection tray

17 Water circulation pump

18, 18A, 18B coolant reversing valve

19A, 19B trickle tray

2 ice cream containers

20 chute

21 conveyors

22 screw conveyor drives

23 cross conveyor

24 screw conveyors

3 water tank

30 water tank containers

31 cold water inlet

32 Cold water drain

4 container scaffolding 40 ice machine containers

41 control valves before 3

42 thermal insulation on 2 and 3

43 coolant separator

49 feeder

5 ice scales

50 shaft

51 lock

52 lock motor

53 fitting cabinet

54 Chilled water pump

55 stairs 56 ramp

57 balance supports

58 support frame

D steam boost line

K condensate line

R return

P pressure gauge

VIl - V14 valves to 14A

V21 - V24 valves to 12A

EV expansion valve

W water pipe

Nl lower trickle water level

N2 upper trickle water level

V15 overflow valve to Nl

CTR control device

IS ice thickness sensor

FC frequency control signal

FG frequency generator

CL clock

NS level sensor

Claims

1. Apparatus for ice cream production, in particular for construction purposes, an ice machine (1) with a heat pump (11) with an ammonia circuit being arranged higher, the condenser (12) of which is cooled by air and water spray and the evaporator (14) of which is made up of vertical evaporator plates water is continuously supplied, which is frozen to ice in a lower-lying ice container

(2) coincides with a demand-controlled extraction device (21), characterized in that the evaporator (14) is operated with an evaporator temperature of about -11 ⁰ C and the water from the bottom side openings of an Rieselwanne (19A) as sprinkled respectively on evaporator plate top edges is passed and the ice formed on the evaporator plates is replaced by periodic bursts of coolant and the trickle water, falls wet into the ice container (2), the discharge device

(21) is arranged in the bottom.

2. Apparatus according to claim 1, characterized in that in a fan evaporator (13) of the condenser (12) accumulating cooled water as the trickle water is fed to the evaporator (14).

3. Apparatus according to claim 1, characterized in that a water tank (3) is arranged next to the ice container (2) and temporarily the evaporator (14) is operated at approximately -3 ° C evaporation temperature and meanwhile cooling water passed through it at a temperature of approx. 1 ° C through a control valve (41) into the water tank (3).

4. The device according to claim 1, characterized in that the discharge device (21) consists of parallel screw conveyors (24) which are driven by electric motors (22) arranged near a container wall.

5. Device according to one of the preceding claims, characterized in that the Ausförderer (21) is arranged slightly rising in the conveying direction and a cross conveyor (23) is arranged below the conveyor side.

6. The device according to claim 3, characterized in that the water tank (3) is arranged in a water tank container (30).

7. The device according to claim 1, characterized in that the ice machine (1) with an electric drive motor (10), a compressor of the heat pump (11), the condenser (12) with the water evaporator fan (13), the evaporator (14 ) with a water circulation pump (17) and coolant reversing valves (18) in an ice machine container (40).

8. The device according to claim 7, characterized in that at least one of the ice containers (2) and at least one of the water tank containers (30) are arranged side by side on the bottom side in a lower level and each on a support structure (4) across these containers (2, 30th ) at least one ice machine container (40) is arranged on an upper floor.

9. The device according to claim 8, characterized in that the ice machine container (40) is arranged so that the evaporator (14) is above an inlet shaft (20) of the ice container (2).

10. The device according to claim 8, characterized in that the containers (2, 30, 40) have standard container dimensions.

11. The device according to claim 8, characterized in that the ice container (2) and the water tank (3) are each surrounded by thermal insulation (42).

12. The apparatus according to claim 2, characterized in that the condenser (12) with the fan-evaporator (13) and / or the evaporator (14) each consist of two parallel sub-assemblies (12, 13; 14) which by means of control valves ( VIl - Vl5; V21 -V24) can be operated and exchanged separately.

13. The apparatus according to claim 5, characterized in that an inclined conveyor (49) is connected to the discharge conveyor (21) or the cross conveyor (23), which is connected on the discharge side to an ice balance (5).

14. The apparatus according to claim 13, characterized in that the ice scale (5) has a shaft (50) which is to be emptied in a controlled manner by a lock motor (52) on the bottom side with a lock (51).

15. The apparatus according to claim 1, characterized in that under the evaporator (14) an inclined sieve plate (15) is arranged, under which a water collecting trough (16) is arranged, to which a water circulation pump (17) is connected, which the collected water leads back into the trickle pan (19A).

16. The apparatus according to claim 15, characterized in that the water circulation pump (17) is controlled by a control device (CTR) such that in the trickle pan (19A, 19B) during an ice formation phase a low level (Nl) and during a defrosting phase a higher one Level (N2) prevails.

17. The apparatus according to claim 16, characterized in that the water circulation pump (17) from the ^' control device (CTR) with a frequency control signal (FC) controls via a frequency generator (FG).

18. The apparatus according to claim 16, characterized in that the control device (CTR) is controlled on the input side with a level sensor (NS) in the trickle pan (19A) and / or an ice thickness sensor (IS) on the evaporator plate and a clock generator (CL).

19. The apparatus according to claim 16, characterized in that an overflow valve (V15) is connected to the trickle pan (19A) at a low level (Nl), which leads to the water collecting pan (16) and at a higher level

(N2) a free overflow to the water collection basin (16) is connected.

20. A method for ice cream production with an ice machine (1), which comprises a heat pump (11) with a condenser (12) and an evaporator (14) consisting of vertically oriented evaporator plates, which are constantly wetted with circulating trickle water and which during a Ice formation phase at an evaporator temperature of approx.

11 ⁰ C are cooled and warmed up during a defrosting phase with a burst of coolant vapor so that the ice formed falls off, characterized in that the trickle water during the defrosting phase has a higher rate than the ice formation phase Evaporator plates is supplied and the defrosting phase is ended after the ice has fallen off.

21. The method according to claim 20, characterized in that the trickle water from a trickle pan (19A) is passed to the upper edges of the evaporator plates and the trickle water in the trickle pan (19A) in the ice formation phase at a low level (Nl) and in the deicing phase is maintained at a higher level (N2).

22. The method according to claim 21, characterized in that water flowing out of the evaporator plates is conveyed back into the trickling trough (19A) in the ice formation and defrosting phases, each with a different conveying speed.

23. The method according to claim 22, characterized in that the conveying speed is time and / or level controlled.

24. The method according to claim 20, characterized in that the rate at which the trickle water is supplied to the evaporator plates during the ice formation phase is adapted to the respective ice formation speed in opposite directions to a respective ice thickness.

25. The method according to claim 24, characterized in that the rate of the trickle water is controlled by means of an ice thickness sensor signal.

26. The method according to claim 25, characterized in that a respective reversal of the ice formation phase and the deicing phase takes place depending on whether an upper or a lower predetermined ice thickness limit has been reached.

27. The method according to claim 20, characterized in that the condenser (12) is acted upon by spray-cooled air and evaporative-cooled spray water is fed to the trickle water.

28. The method according to claim 20, characterized in that the evaporator temperature is raised to about 3 ⁰ C in a cold water formation period and the drained water is drained into a water tank (3).