FR2525490A1 - SCREENING DEVICE FOR THE REMOVAL OF PURIFICATION PRODUCTS FROM THE COOLING WATER STREAM DOWNSTREAM OF A TUBULAR HEAT EXCHANGER - Google Patents

Abstract

A screening device is described for separating purifying bodies from the cooling water stream following a tube heat exchanger, particularly a power station heat exchanger. The screening device includes an essentially cylindrical housing, through which flows the cooling water stream, separating screens arranged therein, a collecting box open at the top and a purifying body discharge. The collecting box has collecting box end walls orthogonal to the separating screens, while the separating screens form the collecting box side walls. They can be pivoted into a separating funnel position and into a cleaning position. At least one of the collecting box end walls runs at an incline to the direction of flow. A guiding body is arranged in the vicinity of the collecting box end wall running at an incline, which guiding body is narrower than the distance between the collecting box side walls and round which the purifying bodies can flow. The guiding body points to the purifying body discharge and is preferably designed as a strip.

Description

 @@@@@@ @e cooling downstream of a tubular heat exchanger, in particular a heat exchanger of # ertrai.es% 1ectriques comprising an essentially c # "indric casing crossed by the stream of water to shrink .ent separating screens arranged in said casing and which can be rotated respectively about a pivot axis, a collector open upwards and a conduit for discharging the purification products, the collector having front walls which extend orthogonally with separating sieves, a bottom plate and side walls which are made in the form of a sieve and directed towards the conduit for discharging the purification products, while at least one front wall of the collector is disposed obliquely to the direction of flow, and the separating sieves which can be rotated in a sieve funnel position and in a n # ettiage position that can engage, at least in the ento position black sieve, with their ends on the flow side between the front walls of the collector or ending at these walls. A pipe for the evacuation or recycling of the purification products is connected to the purification products evacuation pipe. In sieving devices of this kind, a cleaning of the separating sieves which, in the sieve funnel position , serve as separating screens for the removal of purification products from the cooling water stream, is obtained by pivoting the separating screens in the cleaning position. In this position, they are traversed and cleaned by the stream of cooling water, the direction of which is reversed with respect to the position of the sieve funnel. The separating screens are shaped in such a way that the purification products cannot be deposited therein at least in a troublesome proportion, although impurities can accumulate on these screens. The cleaning of the separating screens therefore does not result in a loss of purification products. In addition, it is necessary to also clean the inside of the collector.

 In the well-known sieving device of this kind (European patent 0 026 261), the cleaning of the collect is carried out by opening the collector when the separating sieves pivot in their cleaning position. To open the collector, at least one of the side walls of the collector is attached to the associated separator screen and it can rotate jointly with the bottom of the collector when the separator friends pivot in its cleaning position. Furthermore, in the case of the well-known sieving device, a collector is a relatively narrow aggregate. Between the side walls accumulate not only impurities but also especially purification products. This is particularly so if the side walls of the collector have sieve bars and if the purification products, most often in the form of beads must be directed along the oblique front wall of the collector and transversely to the sieve bars towards the discharge pipe for the purification products. If cleaning of the collector is carried out as described, the deposited purification products are lost. In addition, this cleaning must be carried out very frequently because impurities are deposited in a considerable proportion.

 The object of the present invention is to improve a sieving device of the aforementioned type in such a way that impurities are deposited in a much lower proportion and that the purification products are no longer retained.

According to the invention, this object is achieved by the fact that the collector has, in the region of its oblique front walls, a deflector element which is narrower than the distance between the side walls of the collector and which can be bypassed by the purification products, and that the deflector element is oriented towards the discharge pipe for the purification products. In a preferred embodiment of the invention> the deflecting element has the shape of a rod and is arranged approximately in the middle between the side walls of the collector. Its width may increase in the direction of the purification products discharge duct. In the embodiment with two oblique front walls of the collector, the invention provides that a deflector element is placed in front of each of the front walls and that the two ~ deflector elements are brought together in the region of the evacuation pipe-purification products. In the case of the use of deflector elements in the form of rods, these elements will generally be arranged equidistant from the associated front wall of the collector.
obtained
The advantages lie in the fact that in the screening device according to the invention the impurities:
accumulate much less on the side walls of the
collector produced in the form of a sieve only in the well-known embodiment. Fixation of the purification products can be completely prevented.

 The description which follows, with reference to the accompanying drawings by way of nonlimiting examples, will make it possible to understand clearly how the invention can be put into practice.

Figure i shows an axial section of a dispo
screening screen according to the invention in parallel with the separating screens.

 FIG. 2 represents, in accordance with FIG. 1, an axial section orthogonally to the separating screens.

Figure 3 shows a section along the line
AA of the object of figure i.

Figure 4 shows #a section along the line
BB-of the object of figure l.

 FIG. 5 represents a section along line C-O-of the object of FIG. 1.

 Figures 6 and 7 show, in accordance with Figures 3 and 4, other embodiments of the deflector element in a screening device according to the invention.

 The sieving device shown in the drawings # serves for the elimination of purification products 1 in the cooling water stream 2 downstream of a tubular heat exchanger, in particular a heat exchanger of power plants. The screening device basically comprises a casing 3 which is essentially cylindrical and crossed by the stream of cooling water, two separating screens 5 arranged in said casing and which can rotate respectively around a horizontal pivot axis 4 and a collector 6 open towards the top.

 The collector 6 has front walls 7 which extend orthogonally to the separating screens 5, a bottom plate 8 as well as side walls 9, 10, which are produced in the form of a screen. The separating screens 5 can be pivoted into a screen funnel position which is indicated in the figures by solid lines. In addition, they can be rotated into a cleaning position which is shown in Figure 2 in phantom. At least in the sieve funnel position, they can engage, with their ends 12 on the flow side, between the front walls 7 of the manifold, as shown in the drawings. But they could also end at the front walls 7 of the manifold in which case the side walls 9, 10, 11 are fixedly mounted in the manifold 6.

 In the exemplary embodiment, the side wall 9 and the bottom plate 8 of the manifold are connected over the entire length to the associated separating screen 5. The opposite side wall of the collector is divided in some way into two parts 10, II, one of which 10 is stationary, while the other 11 represents an extension of the separating screen 5.

The side wall 9 of the manifold described first also constitutes an extension of the separating screen 5, and the two extensions 9, 11 are connected by buckling at 13 to the separating screen 5 itself.

 It appears in particular from a comparative examination of FIGS. I as well as 3 and 4 that the collector 6 has, in the region of its front walls 7 inclined in the embodiment, deflector elements 14 which are narrower than the distance A between the side walls 9, 10, 11 of the manifold. The deflector elements 14 can be bypassed by the purification products 1.

They are oriented towards the discharge pipe for the purification products 15. In the exemplary embodiment and according to the preferred embodiment of the invention, the deflector element 14 is produced in the form of a rod and disposed approximately at the middle between the side walls 9, 10, 11 of the manifold. Its width increases in the direction of the discharge pipe for the purification products 15. Since, in the exemplary embodiment, this is the embodiment with two front walls 7 of the manifold inclined relative to the vertical, the The drawings also show that the two deflector elements 14 of these front walls 7 of the collector are joined in the region of the discharge pipe for the purification products 15. Furthermore, they extend equidistantly by ra # pport à their associated front walls 7.

 Figures 6 and 7 show other conformations and transverse profiles of the deflector elements 14 which have proven themselves.

Claims (5)

 1. Screening device for the elimination of purification products in the cooling water stream downstream of a tubular heat exchanger, in particular of a heat exchanger of electric power stations comprising an essentially cylindrical casing worked by the stream of cooling water, separating screens arranged in said casing and which can be rotated respectively around a pivot axis, a collector open upwards and a conduit for discharging the purification products, the collector having front walls which extend orthogonally to the separating screens, a bottom plate and side walls are produced in the form of a bt screen directed towards the conduit for discharging the purification products, while at least one front wall of the collector is arranged obliquely relative to the flow direction, and the separating screens which can be rotated to a screen funnel position and in a cleaning position which can be engaged, at least in the sieve funnel position, with their ends on the flow side between the end walls of the collector or ending at these walls, characterized in that the collector (6 ) has, in the region of its inclined front wall (7), a deflector element (14) which is narrower than the distance (A) between the side walls (9, 10, 11) of the manifold and which can be bypassed by the purification products (1), and that the deflector element 414) is directed. towards the purification products evacuation pipe (15).  2. Screening device according to claim 1, characterized in that the deflector element (14) is produced in the form of a rod and arranged approximately in the middle between the side walls (9, 10, 11) of the collector.  3. Screening device according to one of claims 1 or 2, characterized in that the width of the deflector element (14) increases in the direction of the pipe for discharging the purification products (15).  4. Screening device according to one of claims 1 to 3 in the embodiment with two inclined front walls of the collector, characterized in that in front of each front wall (7) of the collector is a deflector element (14) and that the two deflector elements (14) are joined in the region of the discharge pipe for the purification products (15).  5. Screening device according to one of claims 1 to 4, characterized in that I1 deflector element (14) is arranged equidistant from the front wall (7) of the collector.