JPS613632A - Heat exchanger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger for cooling fine-grained bulk material, in particular sand (for example foundry sand), consisting of a housing and a bulk material backpressure system arranged below the housing.

For cooling bulk material, in particular foundry sand, so-called back-pressure coolers are used, in which the bulk material to be cooled is slowly guided to a cooling surface. The transport of the bulk material takes place by gravity, and the temporal passage is maintained by means of a so-called backpressure system.

In known backpressure coolers, the bulk material is guided below the cooling surface through slits or holes, the passage speed being adjusted by means of vertically movable variable bars and grooves. The backpressure rate can then be adjusted by the resistance of the angle of rest resulting from the vertical pressure of the later sliding sand.

This cooling system automatically adjusts the passing speed of the bulk material to v
, b. The grooved gate forms a single passage for the sand cooling system, making it impossible to maintain a constant sand temperature at the exit. The heated surfaces of the cooling system must be dimensioned substantially more closely.

Other backpressure coolers of the above type have a backpressure system consisting of two overlapping perforated plates, the removal perforated plate being tightly clamped, while the lower perforated plate is closed and controlled. There is no force unless it acts as a slider.

Perforated plates have the property that controllability can only be ensured within very narrow limits. If a close interlocking of the passage holes is desired, then both plates must also be mounted at a very narrow distance from each other.

After an already short pause, the board-spanning chamber is filled with sand;
The lower slider can still only be moved with very high forces. Additionally, this back pressure system is severely corroded.

The object of the invention is to create a backpressure cooler of the type mentioned at the outset, which ensures uniform sand passage, can be adjusted to wide limits and can be used as a quick closure.

Furthermore, the backpressure system must be insensitive to different flow characteristics of the bulk material.

To solve this problem, according to the invention, the loose bean first flows through a screen surface with uniformly distributed passage drying L into a large number of chambers, with each chamber being It is sufficient to have a single outlet of relatively large diameter.

A slider system is mounted below these exit holes, which allows the sand passing through to be controlled over a wide adjustment range depending on the slider position.

The slider can also be moved under the lower perforated plate to the fully closed position.

The sand flows over the waterfall, so to speak. While the bay inlet with uniformly divided holes achieves uniform sand passage, the slider under the second waterfall plate has a positional force; This can cause the formation of grooves, but only in the area of each chamber below the upper perforated plate. The various passages of sand can no longer be continued in this heat exchanger system.

The back-pressure cooler according to the invention is suitable for both small and large production capacities, and surprisingly, it is suitable for even the smallest production capacity without resulting in regulation or throughput problems. Also suitable for cooling bulk materials with a resting angle.

Another advantage of the backpressure cooler according to the invention is the increased adjustment range. By swinging the slider system, the adjustment range of Q - 100% can be achieved in a simple manner. This requirement cannot be met with a cooler having a circumference of 4o.

Also, the spacing of the slider system from the lower waterfall plate can be chosen very large, so that this heat exchanger is not susceptible to corrosion. The latter is particularly important when bulk materials with a wide grain size composition and high hardness also need to be cooled quickly. This problem could not be met with coolers of known construction.

According to another feature of the invention, the sand falls are separated by perforated plates, which can also be used as a support structure for the large weight of bulk material present therein.

Furthermore, with a very small adjustment, if the crater structure within the waterfall continues in the -L direction, the above-mentioned partitioning perforated plate allows the sand within the waterfall to flow out into the adjacent chamber. A perforated plate counteracts this effect.

The waterfall structure described above can now also perform additional tasks. This is because the waterfall structure provides a support structure with bending rigidity for the bulk material loaded thereon.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

The heat exchanger shown in FIG. 1 consists of a housing 1 (preferably a steel plate housing), a bulk material inlet 2 and a heat exchanger 3 through which a cooling medium flows.

The backpressure cooler consists of a sandfall section 4.9.10, below which a slider system 5 is arranged, the slider system 5 being connected to an adjustment drive 6, which controls the slider. It can be moved both to the closed position and to the closed position.

The sand flowing down leaves the cooler via a hopper 7.

The partial section in FIG. 2 essentially shows the cooling housing 1 with the heat exchanger system 3 and, in particular, the sand cascade 4.9.10 with the slider system 5.14.6.

The bulk material 8 to be cooled flows through uniformly arranged holes 11 in the upper box board 9 into a waterfall 13 . There, the bulk material forms a uniform surface and, if the slider position is small, also forms a passage crater.

The loose material exits the pupil through the hole 12 in the lower box board 10.

Various positions of the slider 5 below the box plate hole 12 are adjusted by an adjustment drive 6. The slider 5 is the lower structure 1
It is supported on 4.

The slider passing position and the slider closing position are likewise shown in FIG.

The spacing plate 4 in the sand waterfall section is made of a perforated plate. At low loads, asymmetrical sand craters may form in the waterfall due to the narrow slider position; this (theoretical) mechanism is eliminated by the holes 15 in the spacing plate 4. The loose material flows through the hole and into the next chamber and floats across it. This condition ensures that the bulk material passage holes 11 in the upper box plate 9 always remain free, even at the lowest production capacity, so that the bulk material passage through the cooling system is possible under all loads and A uniform effect can be obtained even when the particle size is varied.

Another feature of the present invention is the formation of a passage hole 12 below the sand waterfall section. Even if these passage holes are designed in the shape of a triangular hole, a long hole, or a T-shaped hole, it will no longer affect the formation of a crater above the box board 9, but the adjustment slider 5.
6.14 Enhance and improve the adjustment characteristics of the drum.

The slider 5 can of course also be designed in the form of a vertically movable truncated content 1. However, this solution is not functional if the cooling unit is relatively small.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view of a heat exchanger with a back pressure system drawn thereon, and FIG. 2 is a longitudinal sectional view of the back pressure system showing the function and structure of the sand passage pupil.

Claims (7)

[Claims] (1) Housing (1), inlet (2), cooling system (3)
) and an outlet hopper (7), in which the bulk material-backpressure system comprises an upper perforated plate with relatively small passage holes (11). (
9) and a lower cascade plate (10) with a relatively large outlet hole (12). (2) Lower waterfall - 9- respectively in each of the passage holes (12)
2. Heat exchanger according to claim 1, in which 25 upper waterfall passage holes (11) are assigned. (3) The waterfall plates (9, 10) are separated by perforated plates (4) so that the loose sand (8) in the waterfall chamber (13) can flow or float into the adjacent chamber; 3. The heat exchanger according to claim 1, wherein the edge sand waterfall portion is also formed as a support structure having bending rigidity for the bulk material. (4) Any of claims 1 to 3, wherein the lower waterfall hole (12) is formed in the form of a triangular hole, an elongated hole or a T-shaped hole in order to increase the control ability. The heat exchanger described in one of the above. (5) From claim 1, wherein the single passage area of the lower cascade hole (12) is at least 8 times larger and at most 16 times larger than the single pore area of the upper cascade hole (11). The heat exchanger according to any one of items up to 4. (6) Below the waterhole (12), a closing and adjusting slide (5) is arranged in the form of a round iron, a prism or a specially formed ring piece.
The heat exchanger according to any one of Items 1 to 5. (7) The lower waterfall holes (12) consist of round holes, which can be brought into any partially loaded or closed position with vertically moved closing cones. The heat exchanger according to any one of Items 1 to 6.