JPS58182099A - Method of purifying 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 method for purifying a heat exchanger system for heating or cooling gas.

Pub-type heat exchanger systems for heating or cooling gases are known. Widespread are, for example, rotary heat exchangers according to the Ljungström principle, which have a heat store in the form of stationary shaped plates, tubes or sheets, which is connected to a temperature-measuring gas stream. It moves cyclically from the air to the cold gas stream, absorbing and releasing heat as it does so. Heat exchangers are also often used in which a hot or cold medium (for example steam or water) flows through a tube or other hollow body, and a gas flows around its outer surface.

When known heat exchangers are used to heat or cool dust-laden gases, deposits easily form on the heat exchange surfaces. It is extremely difficult to eliminate crusting and stickiness in heat exchanger systems when temperatures are below the dew point or when water droplets or aerosols are entrained in the gas, such as in wet-purified flue gases. Have difficulty.

The scab-like skin formed on such heat exchanger threads reduces pressure losses in the heat exchanger and further impedes heat transfer between the gas and the heat exchange surface.

The known heat exchangers installed in such systems are therefore partially equipped with extremely complex purification devices.

It is then known to clean heat exchange surfaces with steam, air or water spray. This usually requires very high pressures and very high equipment costs (DE 29 48 201). In the area of steam cans, mechanical cleaning methods are also known, for example, in which the heat exchange surfaces are periodically cleaned with a rain of steel balls.

It is also known (e.g. U.S. Pat. No. 793,648) to place a layer of separated particles, such as spheres, in front of the actual heat exchange surface as dirt trapping means, but this solution does not Deposits in the deposited layer cause significant pressure losses and must therefore be replaced and cleaned periodically. In another system, described in U.S. Pat. No. 3,872,918, a rotary heat exchanger is filled with a number of moving elements in the form of stacked layers, which transfer heat to the tube walls and, by their movement, Clean the exchange surface.

This solution would result in relatively high equipment costs, high pressure losses in the deposited layer, and moreover, the relatively small movements in such a layer significantly limit the cleaning effect.

The object of the invention is to provide a simple and effective method for purifying heat exchangers used for heating or cooling gases in such a way that heat transfer and pressure losses can be kept constant over long operating times. There is a particular thing.

This purpose, according to the invention, is to provide a heat exchanger with elements such as a number of spheres, hollow spheres or saddle-shaped bodies that can move freely in the gas, either constantly or occasionally forming a vortex layer. This is achieved by deploying it in dangerous areas.

More specifically, the invention provides a gas storage system having a rotating heat store or a rotating gas passageway, or having a chamber into which a hot or cold gas flows, and in which a gas-permeable partition is arranged transversely to the gas flow. - a method for purifying a gas-heat exchanger, in which a deposit layer is formed between at least two said partitions, which may also be formed by the heat store itself, by an inflow of gas from above downwards; Contains elements that can be moved in a number of ways, such as forming a fluidized bed by the inflow of gas, and such fluidized bed is retained in at least one area of the heat exchanger during actuation to form a fluidized bed. A method is provided, characterized in that deposits are constantly removed by mutual collision and mutual friction of the elements. Also a method of purifying heat exchangers in which the gas is heated or cooled by a second medium flowing through a tube, fin tube or other hollow body, containing a number of separate elements within the gas space. However, this also provides a method which is characterized in that during the operation of the heat exchanger a fluidized layer is formed and by its collisions and friction the heat exchange surfaces are kept constantly and free of deposits. Examples of these include the elements being formed as spheres, hollow spheres or sadoids, yet the elements comprising or being made of latent heat storage or high heat capacity materials. This purification method can be used in rotary heat exchangers with radial gas flow.

In rotary heat exchangers, the elements in the fluidized bed achieve constant cleaning of the heat exchange surfaces by collision or friction. It has been found that in rotary heat exchangers, crusts and deposits formed by the joint action of moisture and contained dust are produced, especially in the cold gas inlet areas. According to the invention, on the side of this inlet area, in the case of a rotary heat exchanger that operates with self-flow and has a vertical axis, this element serves as a dirt trapping means in the form of a deposit layer, so that no sticky residue is caused by this element. During the rotation of the rotating body (rotation or movement of the gas passages as in other known heat exchanger systems) the elements transform into a vortex layer in which deposits are automatically removed by collisions and friction. to remove.

In certain applications it is advantageous to arrange such devices on both sides of the heat exchanger, ie on the cold gas inlet side and on the hot gas inlet side. In the case of heat exchangers driven by direct current, the elements are arranged on the inlet side, the inflow being such that the elements form a fluidized bed on both sides of the heat exchanger.

This method can also be easily applied to known rotary heat exchangers with radial flow.

Examples of elements suitable for the purification method of the invention and their arrangement in known heat exchanger systems are shown in FIGS. 1 to 4.

FIG. 1 shows a spherical (hollow or solid sphere) element 1 of the purification reservoir.

FIG. 2 shows a cleaning element 1a formed as a saddle-shaped object.

FIG. 6 shows a heat exchanger suitable for the method of the invention, having a rotating body 2, a housing 6 and a vertical shaft 4 according to the Ljungström principle.

Element 1.1a forms a deposit layer 7 which acts as a dirt trapping means on the inlet side of the cold gas 8, where there is a risk of the formation of a crust, and this element forms in the vortex layer A on the outlet side of the hot gas 9. It is purified by

FIG. 4 shows a tube heat exchanger with tubes 7 through which a heating or cooling medium 11 flows and for heating--but not yet cooling--a gas 10 with an element 1.1a located in a fluidized bed.

[Brief explanation of the drawing]

1 is a perspective view of a spherical element, FIG. 2 is a perspective view of a saddle-shaped element, FIG. 6 is a perspective view schematically showing a heat exchanger according to the Ljungström principle, and FIG. 4 is a perspective view of an alternative heat exchanger. FIG. 2 is a schematic perspective view; In the drawings, 1 and 1a are elements, 2 is a rotating body, 3 is a housing, 6 is a fluidized layer, 7 is a deposited layer, 7' is a tube, 8 is a low temperature zone, 9 is a high temperature zone, and 11 is a hot or cold medium. shows. Engraving of the drawings (no change in content) Figure 1 Figure 2 Procedural amendment (method) Date of 1939 To the Commissioner of the Japan Patent Office 1, Indication of the case 1988 Patent application No. 9788'/B1, Name of the invention Method for purifying the exchanger 3, relationship with the case of the person making the amendment Patent applicant address r rowsaishi ot τ de pa 54yp7). 4. Agent Address: Bussan Building Annex, 1-1-15 Nishi-Shinbashi, Minato-ku, Tokyo Phone: (591) 0261459-

Claims (1)

[Claims] 1. Having a rotating heat storage device or a rotating gas passage, or having a chamber into which high-temperature or low-temperature gas flows instead,
In a method for purifying gas-gas heat exchangers in which the gas-permeable partitions are arranged transversely to the gas flow, between at least two said partitions, which may also be formed by the heat store itself, there is a It houses elements that can move in many ways, such as forming a deposited layer by the inflow of gas and forming a fluidized layer by the inflow of gas from below upwards, and when driving such a fluidized layer, the heat exchanger A method characterized in that deposits are constantly removed by mutual impact and mutual friction of said elements, which are retained in at least one zone and form a vortex layer.゛2. 2. The method of claim 1, wherein the method is applied to a rotary loaf heat exchanger with radial gas flow. 6. A method according to claim 1 or 2, wherein the element is formed as a sphere, a hollow sphere or a sadoid. 4. Claims 1 and 2m in which the element comprises or is formed of a latent heat storage material or a material with high thermal density.
, the method according to any one of paragraph 3. 5. In a method of purifying a heat exchanger in which the gas is heated or cooled by a second medium flowing through a tube, fin tube or other hollow body, a number of separate elements are placed in the gas space. This forms a vortex layer when the heat exchanger is driven, and its collision and JI! A method characterized in that the heat exchange surface is kept constantly free of deposits by rubbing. 6. A method according to claim 5, wherein the element is formed as a sphere, a hollow sphere or a sadoid. 7. A method as claimed in claim 5 or 6, in which the Z element comprises or is formed of a latent heat storage or heat response tubular material.