WO2011020449A1

WO2011020449A1 - Device for cooling gravel

Info

Publication number: WO2011020449A1
Application number: PCT/DE2009/075043
Authority: WO
Inventors: Otto-Wilhelm Held
Original assignee: Hemack Gmbh
Priority date: 2009-08-17
Filing date: 2009-08-17
Publication date: 2011-02-24

Abstract

The invention relates to a device and a method for cooling goods to be cooled (4), in particular materials for producing concrete, wherein a washing drum (1), a sedimentation tank (2), and an ice machine (3) are connected to each other in such a way that water (5) runs in a circuit through the washing drum (1), the sedimentation tank (2), and the ice machine (3), and the goods to be cooled (4) are cooled in the washing drum (1).

Description

Device for cooling gravel

The invention relates to a device for cooling refrigerated goods, in particular of materials for concrete production.

Concrete cooling is of great importance in southern countries such as the United Arab Emirates, Saudi Arabia and dam projects, as the strength in concrete is influenced by the evolution of heat that forms in the concrete during drying and hardening. The drying heat increases the temperature in the concrete during the drying process by up to 25 ° C and causes an increase in volume. After drying, the concrete cools on the

Ambient temperature decreases under volume decrease, which leads to cracks in the concrete. It is therefore desirable to have the lowest possible starting temperature of the fresh concrete.

From the patent application DE 3312900 Al is a method for the cooling of

Fresh concrete is known in which a portion of the water required for the concrete mixture in the form of flake ice is added to the mixture, which is previously undercooled by means of a refrigerant to low temperatures. In practice, however, it has been shown that the required fresh concrete temperatures in hot climates can not always be achieved with this method. Because of a low

Cement content even relatively little cold water or flake ice can be added to the mixture, the cooling effect is not always sufficient to cool the cement and the aggregate content of gravel and sand accordingly.

It is easy to see that the starting temperature of the supplement

thermodynamically very relevant, as for the production of 1 cubic meter

Fresh concrete typically uses about 1900 kg of gravel and sand, about 250 kg of cement and about 190 kg of water. The patent application DE 102005014356 A1 describes a method for controlling the temperature of fresh concrete, in which the aggregate of gravel and sand is cooled with an ice slurry and allowing the thawed ice slurry and water to drain before mixing the concrete. Disadvantages are the considerable costs, since a lot of energy is needed to produce the ice slurry.

Another common method today is to pull the aggregate of sand and gravel in a long pool of chilled water on a conveyor belt lowered therein through the water. It is also disadvantageous that a lot of fresh water is needed and beyond the heating of the water in the pool, whereby the cooling effect quickly decreases.

It is therefore an object of the invention to provide a device for cooling refrigerated goods, in particular of materials for concrete production, which, compared to the prior art, avoid the disadvantages.

This object is achieved by a device with the features of

Patent claim 1.

Advantageous embodiments and further developments of the invention are specified in the dependent claims.

The invention provides that a washing drum, a settling tank and a

Ice machine are interconnected so that the water circulates through the washing drum, the sedimentation tank and the ice cream machine, while the refrigerated goods are cooled in the washing drum.

The invention is based on an ice machine for the production of ice, in particular for the purpose of concrete mixing, as disclosed in the patent application DE 102005008145 B3. The ice machine is continuously supplied with water, which is cooled down to flake ice, wet ice or cooled water and is available via a discharge device.

This ice maker is with a washing drum and a settling tank over Rohrbzw. Hose lines interconnected so that the water in a circuit through the washing drum, the settling tank and the ice machine and while the refrigerated goods is cooled in the washing drum.

The goods to be chilled are gravel and sand, which are added to cement and water depending on the recipe and type of cement, as a supplement for fresh concrete production. The goods to be cooled are introduced into the washing drum with the simultaneous addition of cooled water, wherein the goods to be cooled remain in the washing drum until the cooling of the goods to be cooled required for the required fresh concrete temperature is achieved. The washing drum has on both sides a round centric opening, wherein the supplied refrigerated goods are introduced through the opening with the larger diameter in the drum. The feed of the rotating drum runs, for example, via a conveyor screw or a conveyor belt and is metered according to the drum volume. The chilled water is fed through a water inlet at the

introduced opposite opening with the smaller diameter.

The attached to the inner wall of the washing drum screw conveyor with many spiral turns promotes the introduced gravel or sand and causes a good penetration of the cooled water.

There are two embodiments of the screw conveyor in the washing drum provided with different methods for cooling.

Common to this method is that the water is pumped in a cycle, wherein the refrigerated goods is filled in the washing drum, the cooled water flows in opposite directions to the goods to be cooled through the washing drum, the refrigerated goods in the long

Washing drum remains until the desired temperature is reached, and the refrigerated goods is discharged from the washing drum.

The chilled goods are discharged from the washing drum and the hot water is fed to the settling tank. In addition, the dripping water of the chilled goods is collected and also fed to the settling tank. After the treatment of the water, the return to the ice machine and thus into the production process, whereby the cost factor is significantly minimized. The treated water is efficiently pre-cooled in an evaporative cooler, and then in the

Ice machine cooled down to the required temperature. In the first embodiment of the screw conveyor is a

low-maintenance, shaftless worm, whereby the worm wall is broken at regular intervals, so that between the wing arms formed thereby the water can flow without turbulences. The screw conveyor ensures by the rotation of the drum for a safe and clog-free forced delivery of the refrigerated goods in the direction of the opening with the smaller diameter. The cooled water runs in the opposite direction to the refrigerated goods through the washing drum. The water may be so obtained in the ice machine cooling potential after the

Heat exchanger principle optimally and completely deliver to the refrigerated goods. The

Washing drum rotates at a rotation speed of one revolution per minute. The water is introduced into the washing drum at a starting temperature of approx. 1 ° C, and the gravel and sand are introduced into the washing drum at a starting temperature of approx. 45 ° C. The washing drum acts as a heat exchanger, in which the cooled water absorbs the temperature of the gravel or sand, whereby the water heated to about 45 ° C is drained from the drum. In this process, the gravel or sand is cooled to about 1 ° Celsius.

In the second embodiment, the screw conveyor is continuous and the

Spiral windings thus form individual chambers for the goods to be cooled and the water.

Breakthroughs are present in a wall-facing circular section of each spiral winding, so that in a passage angular position range of the washing drum, the water flows through the chambers and closed chambers are formed in other angular position ranges. In this case, fixedly mounted stirring rods or plates are advantageously present in the chambers, in a rotary or

Swivel movement of the washing drum stir the refrigerated goods. This will be the

Heat exchange continues to be supported

In the second embodiment, the method of cooling with the following

Steps expanded:

During a first water intake, the washing drum is

Angle position range held until water emerges again at the water outlet side.

Thereafter, the washing drum is rotated 180 °, so that between the

Spiral turns form closed chambers. Now the washing drum is changed by approx.

90 ° swung back and forth, wherein in each chamber, a heat exchange between the Refrigerated goods and the water takes place. The swinging back and forth takes place until the temperature of the chilled goods has adjusted in the respective chamber to about 2 ° to the local water temperature. Thereafter, the washing drum is rotated in the passage angular position range, and added a further amount of cold water in the washing drum, which corresponds approximately to the volume of a chamber. Then the cooling process is continued with the swinging back and forth.

The rotation of the drum, the goods to be cooled is conveyed from one chamber to the next and discharged at the end. The largely closed drum body prevents escape of the

Cooling potential to the ambient air and thus a harmful heating of the drum interior. On the water inlet side of the washing drum, the cooled goods to be cooled out with a special Becherausförderer out of the drum. The removal of the cooled goods to be cooled then takes place via a chute or conveyor belt with discharge in a transport container. The drum drive is a frictionless drive that is insensitive to interference.

In one embodiment of the invention, the washing drum with a

Overcurrent warning device to be equipped, the intake current of

Drive motor measures and by means of warning lamp or warning tone indicates the achievement of a maximum allowable amount of refrigerated goods and water.

It is advantageous over the chute or the conveyor belt, via which the cooled chilled goods are conveyed out of the washing drum, and over the transport container in which the discharge is a roof provided, which prevents harmful heating of the chilled by the sunlight.

Below the chute or the conveyor belt, a collecting container for dripping water is arranged, which collects the dripping water from the chilled goods. The collected water is sent for reuse to the settling tank where it is treated so that it can be returned to the water cycle. In comparison with the prior art, the same amount of gravel or sand is cooled particularly advantageously with a smaller area requirement with a significantly higher cooling effect and in a shorter time. Due to the different sized openings of the washing drum always remains the greater part of the cooled water in the drum for cooling the goods to be cooled and a small part of the water flows through a water outlet into a settling tank.

This ensures a constant replacement of the cooled water and a consistently low temperature of the water in the drum, which causes an optimal cooling effect of the refrigerated goods.

In Absetzbecken a plurality of parallel overflow channels is arranged at the upper edge transverse to the basin, which are formed in a V-shaped lamellar structure. The contaminated process water from the washing drum is introduced via a water inlet pipe in the settling tank, which is a virtually flow-free

Basin is. The solids contained in the process water settle under the influence of gravity at the bottom of the pool, which is known as sedimentation. The clarified water flows through surface movement of the water over the two lamellar edges of the overflow channels, where it is collected by the V-shaped channel and flows to the gutter. The water of all overflow channels is collected in the gutter 11 and discharged through a water outlet pipe of the settling tank, whereby a pump ensures that the water is supplied to the ice maker. The sediments of the chilled goods deposited at the bottom of the sedimentation tank are drained via a funnel and an outlet valve. The amount of sediment in the sedimentation tank is advantageously determined by the current weight of the sedimentation tank and, controlled by it, the outlet valve is opened.

The ice machine provides two-stage cooling of the water supplied from the settling tank. First, the approx. 45 ° Celsius water is cooled down to a wet bulb temperature of approx. 25 ° Celsius by means of a blower in an evaporative cooler. The air is guided past the water with the flow speed of the fan and the water is cooled to the wet bulb temperature with the resulting evaporative cooling. Thereafter, the further cooling of the Water in the ice maker itself to about 1 ° Celsius. This two-stage cooling ensures a very good energy efficiency.

The invention provides that the settling tank and the ice machine can each be installed in a standard container or both together in a common standard container. Standard containers are standardized for international transport and have corresponding outer dimensions and connections for lifting or fastening and coupling. Along with the washing drum, the entire apparatus can be advantageously loaded onto a truck, railroad car or ship, allowing for quick and safe transport to a new production site and, moreover, reducing freight costs. All parts of the device are housed inside the container, which makes them well protected against transport and Wandalismus damage. An embodiment of the invention is described by way of example in the figures.

Fig. 1 shows schematically the device for cooling.

Fig. 2 shows a longitudinal section through the washing drum

Fig. 3 shows a cross section through the washing drum with wings

Fig. 4 shows a cross section through the washing drum breakthroughs

Fig. 5 shows a settling tank in plan view.

Fig. 6 shows a settling tank in cross section in a lateral view

In Fig. 1, the device for cooling refrigerated goods is shown, the top center a washing drum 1, bottom left a settling tank 2, and bottom right has an ice maker 3.

In the washing drum 1, the refrigerated goods 4 is introduced on the left side by a larger opening. On the right side of the drum 1 is by a

Water inlet the cooled water 5 from the ice cream maker 3 in the drum. The washing drum 1 rotates, the goods to be cooled by the on

Inside wall of the drum attached screw conveyor 19 is transported in opposite directions to the watercourse in the drum. The chilled goods remain in the drum until it has cooled to a desired temperature. Thereafter, the refrigerated goods are dropped via a chute or conveyor belt 6 in a transport container 8. The Tarnsportcontainer 8 is transported to a concrete mixer, where the refrigerated goods 4 is mixed together with the cement and water to a fresh concrete with a required low temperature. Under the chute or conveyor belt 6, a collecting container 8 for the dripping water from the refrigerated goods 4 is arranged. The collected water 5 is fed via a pipe or hose to the settling tank 2. About a water collecting container on the left side of the washing drum 1, the heated water 5 of the drum 1 is discharged and fed to the settling tank 2 via a pipe or hose line. In the settling tank 2, the contaminated water 5 is cleaned, and fed via a pump 9 of the ice maker 3. The settled sediments in the settling tank 2 can be recycled to the refrigerated goods 4.

The ice maker 3 cools down the water 5 in two stages. First, the water in an evaporative cooler 17 by means of a blower 18 on the

Wet bulb temperature cooled down. The wet bulb temperature is the lowest

Temperature that can be achieved by evaporative cooling. After that it will be

Water in the ice machine 3 even cooled down again and fed to the water inlet of the washing drum 1.

In Fig. 2 is a longitudinal section through the washing drum is shown.

Along the inner wall of the washing drum 1, a screw conveyor 19 is welded.

Due to the rotational movement of the washing drum 1, the refrigerated goods 4 after

Operating principle of the Archimedean screw against the direction of the water 5 transported in the drum.

The spiral turns 21 of the screw conveyor can be designed in two ways.

Once the spiral turns are designed as wings, as shown in Fig. 3, through which the water can flow without turbulence. In this embodiment, the washing drum 1 rotates continuously.

In the second embodiment, the spiral turns 21 are continuous and form

Chambers 22. Only in a circular portion of each spiral winding 21 openings are present, as shown in Fig. 4.

In this second embodiment, the washing drum is pivoted back and forth after a turning operation. About the left opening 12 of the washing drum 1, the refrigerated goods is introduced. At this left opening 12 and a water collecting basin is attached, via which the

Domestic hot water is collected from the drum. The service water is with

Sediment of the chilled goods 4 contaminated and is therefore to clarify the

Supplied settling tank.

On the right side of the drum 1, the opening can be seen, over which the cooled goods to be cooled is discharged. To protect against heating by the direct

Solar radiation, this right opening is provided with a roof 16. Here also the water inlet pipe 14 is arranged.

Between the drum 1 and the right opening of the Becherausförderer 13 is arranged, which is equipped with all around with several cups that move with the rotation of the drum 1 in each case by one position. When a cup has arrived in the uppermost position, the cup empties its refrigerated goods 4 located therein by gravity, which then via a chute or a conveyor belt in the

Transport container is dropped. The washing drum 1 is by means of a

Reibradantriebes offset by a drive motor 15 in a rotary rotary motion.

In Fig. 3 is a cross section through the washing drum 1 with the first embodiment of a spiral winding 21 is shown. It consists of a plurality of vanes 23 which are internally attached to the wall 26 of the washing drum. In the lower part of the refrigerated goods 4 is conveyed in the water 5 through the washing drum 1.

In Fig. 4 is a cross section through the washing drum 1 with the second

Embodiment of a spiral winding 21 shown. It is continuous and internally attached to the wall 26 of the washing drum. The beginning and end of a spiral winding 21 is indicated by the dividing line 27. Thus, a chamber is formed in each case.

The washing drum is drawn in the passage position. In the lower part of the spiral winding 21, the apertures 24 are present, which allow the flow of water 5 from one chamber to the next. The refrigerated goods 4 lying in the lower region is conveyed by the rotation of the washing drum 1 in the next chamber. The washing drum is rotated for cooling by 180 ° and then pivoted back and forth, which is indicated by the upper double arrow. The refrigerated goods 4 is further stirred by the stirring rods 25 in the water, thus accelerating the heat exchange.

In Fig. 5, a settling tank is shown in plan view. Here the arrangement of six overflow troughs 10 and a gutter 11 is shown. The overflow troughs 10 are arranged transversely to the settling tank 2 and at the upper edge of the basin. From the left side of the basin, the contaminated water is introduced into the basin via a water pipe 14. The water 5 is clarified in the tank, in which the solids 4 located in the water are sedimented by gravity and thus a separation of the liquid is achieved. The thus clarified water 5 all overflow channels 10 is collected in the gutter 11 and discharged via a water pipe 14 on the right side of the settling tank 2.

In Fig. 6, the sedimentation tank 2 is shown in cross-section in a lateral view. The clarified water 5 can easily run over the two edges of the overflow channel 10, is collected there and flows to the gutter 11 back from. The solids in the water are separated by gravity and are collected at the bottom of the settling tank 2. The soil is chamfered to the middle and through an outlet 20, the contents of the settling tank and thus the solids are discharged.

LIST OF REFERENCE NUMBERS

1 washing drum

2 settling tanks

3 ice cream maker

4 refrigerated goods

5 water

6 slide, conveyor belt

7 collection container

8 transport containers

9 pump

10 overflow troughs

11 gutter

12 opening

13 cup conveyor

14 water pipe

15 drive

16 roofing

17 evaporative cooler

18 blowers

19 screw conveyor

20 outlet

21 spiral winding

22 chamber

23 wings

24 breakthrough

25 stir bar

26 wall of the washing drum

27 Separation of a chamber

Claims

claims

1. Apparatus for cooling refrigerated goods (4), in particular of substances for

Concrete production, characterized in that

a washing drum (1), a settling tank (2) and an ice maker (3) are connected to each other so that water (5) circulates through the washing drum (1), settling tank (2) and ice maker (3) and the refrigerated goods (4) in the

Washing drum (1) is cooled.

2. Apparatus according to claim 1, characterized in that

the goods to be chilled (4) are sand and / or gravel.

3. Device according to claim 1, characterized in that

the settling tank (2) has overflow channels (10) transversely to the tank at its upper edge over which the water (5) flows out of the settling tank (2).

4. Apparatus according to claim 1, characterized in that

the settling tank (2) has a discharge funnel through which sedimented solids are discharged.

5. Apparatus according to claim 1, characterized in that

the ice machine (3) has an evaporative cooler (17) which pre-cools the water (5) by means of a blower (18).

6. Apparatus according to claim 1, characterized in that

the washing drum (1) has at both ends round central openings (12), of which the opening at its water inlet side has a smaller diameter than the opening (12) at the water outlet side.

7. Apparatus according to claim 6, characterized in that

the washing drum (1) at the water inlet side has a Becherausförderer (13) which conveys the refrigerated goods (4) via a chute or conveyor belt (6) in a transport container (8).

8. Apparatus according to claim 7, characterized in that under the chute or the conveyor belt (6), a collecting container (7) for

Dripping water (5) is located.

9. Device according to claim 1, characterized in that

the sales basin (2) and the ice machine (3) are each installed in a standard container or in a common standard container.

10. Apparatus according to claim 9, characterized in that

There is a roof over the chute or the conveyor belt (6) and the transport container (8), which prevents harmful heating of the refrigerated goods (4) by sunlight.

11. The device according to claim 1, characterized in that

the washing drum (1) inside a on the wall (26) of the washing drum mounted screw conveyor (19) with many spiral turns (21), which forcibly conveys the refrigerated goods (4) to the flow direction of the water (5).

12. The device according to claim 11, characterized in that

the spiral turns (21) are designed as wing arms (23), so that the water (5) can flow without turbulence between the chambers (22).

13. The apparatus according to claim 11, characterized in that

the spiral turns (21) of the screw conveyor (6) are designed to be higher than the water level in the washing drum and thus a chamber (22) is formed in each spiral turn (21) which has openings (24) in a circular section of each spiral turn (21) close to the wall such that in a passage angular position range of the washing drum, the water (5) flows through the chambers (22) and closed chambers are formed in other angular position ranges.

14. The device according to claim 1, characterized in that

Stirring rods (25) or plates are fixed in the chambers

15. A method for cooling refrigerated goods (4), characterized in that

- Water (5) is pumped in a device according to claim 1 in a circuit,

- The refrigerated goods (4) is filled in the washing drum (1),

the water (5) passes through the washing drum (1),

- The cooled water (5) opposite to the refrigerated goods (4) through the washing drum (1) flows,

- The refrigerated goods (4) in the washing drum (1) remains until the desired temperature is reached, and

- The refrigerated goods (4) from the washing drum (1) is discharged.

16. The method according to claim 15, characterized in that

the water (5) is pre-cooled in an evaporative cooler (17).

17. The method according to claim 12 and 15, characterized in that

the flow rate of the water (5) and the conveying speed of the chilled goods (4) is kept so low that a nearly complete heat exchange between the water and the chilled goods takes place.

18. The method according to claim 17, characterized in that

the rotational speed of the washing drum (1) is about one revolution per minute.

19. The method according to claim 13 and 15, characterized in that

during a first water inlet, the washing drum (1) is held in the forward angular position range until water emerges again at the water outlet (12),

- After the washing drum is rotated by 180 °, so that form closed chambers (22),

- The washing drum is swung back and forth by 90 °, wherein in each chamber (22) takes place a heat exchange between the refrigerated goods (4) and the water (5),

- The swinging back and forth takes place until the temperature of the chilled goods (4) has adjusted in the respective chamber to about 2 ° to the local water temperature,

after that the washing drum is turned into the passage angular position range, - Added another amount of cold water in the washing drum (1), which corresponds approximately to the volume of a chamber (22), and

- The cooling process continues with the swinging back and forth.

20. The method according to claim 15, characterized in that the degree of filling of the settling tank (2) with solids by weighing the settling tank is determined and when exceeding a certain weight of the content of the settling tank (2) is drained.