Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
  • F27D15/02—Cooling
  • F27D15/0206—Cooling with means to convey the charge
  • F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
  • F27B7/20—Details, accessories, or equipment peculiar to rotary-drum furnaces
  • F27B7/38—Arrangements of cooling devices
  • F27B7/383—Cooling devices for the charge
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
  • F27D15/02—Cooling
  • F27D15/0206—Cooling with means to convey the charge
  • F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
  • F27D15/022—Cooling with means to convey the charge comprising a cooling grate grate plates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
  • F27D15/02—Cooling
  • F27D15/0206—Cooling with means to convey the charge
  • F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
  • F27D15/022—Cooling with means to convey the charge comprising a cooling grate grate plates
  • F27D2015/0233—Cooling with means to convey the charge comprising a cooling grate grate plates with gas, e.g. air, supply to the grate

Definitions

• the present invention relates to a method for cooling a bed of particulate material supported on an air distribution bottom using air which via ducts is conducted in sec- tionalised manner to and directed up through the air distribution bottom and the bed of material from one or several underlying compartments, while the particulate material is transported horizontally or slightly tilted from the inlet end to the outlet end of the distribution bottom.
• the invention also relates to a device and an apparatus for carrying out the method according to the invention.
• An example of an apparatus which comprises an air distribution bottom is a cooler for cooling, for example cement clinker.
• the primary aim is to achieve a favourable degree of heat exchange between the clinker and the cooling air so that essentially all the thermal energy contained in the hot clinker can be returned to the kiln system in the cooling air, while at the same time the clinker is discharged from the cooler at a temperature which is close to the ambient temperature. It is a precondition for achieving a favourable degree of heat exchange that the cooling air flow through the clinker is well-defined and quite homogenous.
• the clinker In connection with the cooling of cement clinker which is discharged from the kiln installed ahead of the cooler it has, however, emerged that the clinker is not always uniformly distributed across the width of the cooler. Instead, there is a tendency towards the clinker being distributed so that the larger clinker lumps are predominantly located at the one side of the cooler, whereas the fine clinker lumps are located at the other side. Also, the thickness of the clinker bed may exhibit variations both longitu- dinally and transversely through the cooler.
• any such uneven distribu- tion of clinker often entails that the finer clinker material is not sufficiently cooled, hence causing hot zones, so-called "red rivers", to be formed in the cooler.
• Such uneven distribution of the clinker will also entail that the cooling air in the areas where it encounters least resistance will simply cool the clinker more, due to the higher air flow through the clinker bed in the area.
• the heat exchange efficiency of the cooler is essential for having the highest possible air temperature returning to the process, after heat exchanging with the clinker.
• the present invention will obtain a desired cooling of clinker for upside conditions that was not achievable before with EP0848646, without having too big fan design.
• the present invention will obtain easy adjustment of the flow rate without changing any parts of the device, hereby being able to obtain optimal heat exchange for different production rates etc.
• the present invention addresses these issues by providing a device for use in a bottom construction of a bed for cooling particulate material, where said device comprises a frame comprising means for fastening said device to the bottom construction, and where inside the frame a primary and a secondary opening is provided, where said primary and secondary openings allow cooling air to pass through the frame and thereby through the bottom and through the bed of particulate material, and where a pendulum plate is pivotably arranged on an axle, such that the pendulum plate may pivot and thereby block off more or less of the secondary opening, and where said pendulum plate is biased towards a position allowing the secondary opening to be as open as possible.
• a shutter plate is provided in the frame, where said shutter plate steplessly may be adjusted between positions where the shutter is not blocking or substantially completely blocking said primary and/or secondary openings.
• the shutter serves to adjust the airflow both of the open section which the pendulum plate does not influence and the section in which the pendulum plate adapts the airflow area by pivoting from its non-blocking position to any position suitable, until substantially blocking the opening, such that depending on the size of the production going on in the cooler and the device's position in the cooler, preset airflows may be adjusted by altering the position of the shutter plate.
• a section of the shutter plate corresponding to the secondary opening is curved, where the curve substantially corresponds to the radius described by the end of the pendulum plate.
• the pendulum plate will provide a more or less linear change in airflow depending on the pressure drop across the bed of clinker and at the same time the space which the entire device occupies is reduced.
• the invention is furthermore directed to an apparatus for cooling a bed of particulate material
• the apparatus comprises an air distribution bottom utilizing air from one or more compartments, which in sectionalised manner direct the air up through the particulate material, the flow of the air through each section is regulated by means of a device.
• the distribution bottom is typically constructed in such a manner that clinker will not fall through the bottom and into the compartments, but will still allow the cooling air to be directed through the particular material.
• Each compartment may comprise one or more devices according to the invention depending on the size of the compartment and the desired airflow through the bed of particulate material, especially clinker, in that particular position in the cooler. It is to be understood that the number/density of devices per area unit may vary through the cooling installation such that the most optimum cooling of the particulate material is achieved before the particulate material is expelled from the cooling device.
• the shutter plate can be repositioned in the di- rection defined by the centre line of the shaft, hereby increase or decrease the primary and/or secondary openings, and supply a new flow rate for each new position.
• This repositioning is especially interesting in cases where the cooling installation is to be treating more or less material or be treating a different kind of material such that the whole airflow into the compartments and thereby also through the bottom of the cooler may be readjusted to that particular purpose.
• the shutter plate such that it may be displaced along a line parallel to the shaft around which the pendulum plate pivots it is relatively easy without any reconstruction of the device to readjust the airflow openings in the device per se.
• the invention is also directed to a method for cooling a bed of particulate material which is supported by an air distribution bottom, utilizing air from one or more compartments, which in sectionalised manner direct the air up through the particulate material; the flow of the air through each section is regulated by means of a device, where a pendulum plate swings around a shaft; where the device comprises primary and secondary openings, and where the area of the primary opening is adjusted by a shutter plate member, and where the secondary opening has a dual adjustment mechanism comprising a biased pendulum plate, and a shutter plate for adjusting the open area of the secondary opening.
• the pendulum plate can swing above the upper edge of the shutter plate and create a larger area for airflow.
• the airflow does not follow the normal flow/resistance for a fixed orifice opening, which normally would be a function including the square root of the air flow.
• the airflow will in this position of the pendulum plate be substantially linear and having a greater increase.
• the invention By being able to pivot the pendulum plate free of the shutter and thereby substantially allowing an unrestricted airflow through the device the invention provides this added function in a very simple and reliable manner without the necessity for extra fans capacity, but simply by increasing the airflow area through the device, allowing more cooling air to be passed through the cooling bottom.
• the bias of the pendulum plate is selected such that during normal operation of the cooling bed, the pendulum plate will not pivot past the shutter plate for adjusting the open area of the secondary opening.
• the biasing means such that the situation where the pendulum plate swings above the upper edge of the shutter plate the device will during normal operation be within the range of airflow which it initially has been set at, namely by displacing the shutter plate relative to the shaft in such a manner that the airflow openings in the device are within the desired range and biasing the pendulum plate such that it will be able to adjust the airflow relative to the expected thickness of the bed of particulate material which is to be cooled.
• Figure 1 illustrates a cooler with an inlet and an outlet
• Figure 2 illustrates a cross section through a device illustrates a 3D isometric view of a device
• FIG 1 a cooler 1 which comprises an inlet end 2 and an outlet end 3.
• the cooler is connected to a rotary kiln 4 from which it receives hot material which is to be cooled.
• the material from the rotary kiln 4 drops onto a distribution bottom 5 provided in the cooler 1 and it is conveyed as a material layer 6 on the distribution bottom 5 from the inlet end 2 to the outlet end 3 of the cooler 1 by means of transport - not shown.
• the means of transport could (but not limited to) be: reciprocating grates, reciprocating bars or a walking floor principle.
• the cooler 1 Under the distribution bottom 5 the cooler 1 comprises of one or more compartments 7, where each is supplied with cooling air from a fan installation 8.
• the compartment 7 may both in the longitudinal direction of the cooler and transversely hereof, be divided into a number of smaller compartments, not shown, and, if so, cooling air is supplied to each single compartment.
• the distribution bottom 5 is sectionalised in a number of smaller distribution areas 9 - called grate plates.
• Each grate plate or group of grate plates is equipped with a flow device 10.
• the flow device 10 consist of a pendulum plate 11 that rotates at a shaft 12, and the pendulum plate 11 is forced open by a spring 13.
• the pressure loss over the device 10 results in a force (area multiplied by pressure) at the pendulum plate 11.
• the force at the centre point of the pendulum plate 11, results in a torque in relation to shaft 12.
• the orifice area 14 consists of:
• the shutter plate 15 can be repositioned by an operator traversing the shutter plate 15 in the direction defined by the centre line of the shaft 12, hereby the orifice area 14 (both secondary 14a and primary 14b) can be changed.
• the flow characteristic value can be changed linear (by repositioning the shutter plate 15) throughout the whole area of operation, where the delta pressure over the device 10 is different.
• the pendulum plate 11 can swing past the top point 16 of the shutter plate 15.
• the total orifice area is increased by a slotted opening, and larger quantities of air can pass without much extra pressure loss over the device.
• figure 4 is illustrated a cross-section through a device corresponding to the device described above with reference to figure 2.
• the pendulum plate 11 has pivoted free of the top edge 16 of the shutter plate 15 such that airflow is not restricted by the pendulum plate through the device 10.
• the figure illustrates the airflow through the device depending on the pressure drop across the bed of particulate material.
• the curves are only illustrative and many other airflows may be achieved with various sizes of the device and capacity of the ventilators.
• the four different lines illustrate four different positions of the shutter plate 15 relative to the openings in the device, i.e. corresponding to different opening areas 14a, see figure 3.
• the bed of particulate material may vary dramatically, and as such instead of providing large ventilators which may provide extra air through the device the pendulum plate 11 may pivot as illustrated with reference to figure 4 into a position where it is free of the shutter plate 15 at the top edge 16, thereby allowing a radical increase in the airflow which is illustrated by the right-hand end of the four lines 20, 21, 22, 23.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Furnace Details (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (3)

Cited By (1)

Citations (5)

Family Cites Families (4)

• 2011
  • 2011-09-05 CN CN201180043707.5A patent/CN103124888B/zh active Active
  • 2011-09-05 WO PCT/DK2011/050332 patent/WO2012031597A1/en active Application Filing
  • 2011-09-05 EP EP11757744.5A patent/EP2614328B8/de active Active

Patent Citations (6)

Non-Patent Citations (3)

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