US 2069963 A
Description (OCR text may contain errors)
Feb. 9, 1937. D. R. MCNEAL ,0
ROTARY STRAINER Filed April 20, 1934 2 Sheets-Sheet 1 INVENTOR Feb. 9, 1937. D. R. MCNEAL i Q 3 ROTARY STRAINER Filed April 20, 1934 2 Sheets-Sheet 2 Q MW ZZW Patented Feb. 9, 1937 UNITED STATES PATENT OFFEQE ROTARY STRAINER Application April 20, 1934, Serial No. 721,447
This invention relates to straining equipment and is especially concerned with certain improvements which are particularly adapted to what has become known in the .art as a rotary strainer.
In this type of mechanism, a strainer rotor is mounted within a casing and the fluid or liquid to be strained is passed through strainer elements carried by the rotor. The invention is concerned with a sealing device which is arranged peripherally of the strainer rotor and cooperates with the casing to effectively seal and separate the inlet and outlet sides of the casing.
The principal object is to provide a highly wear-resistant and effective sealing means of the character mentioned.
Another object is to provide a sealing means which automatically makes the seal tighter when the pressure drop across the strainer is increased.
The nature and objects of the invention will be understood to better advantage after consideration of the following description making reference to the accompanying drawings which illustrate a preferred embodiment. At this point it is noted that the present invention constitutes an improvement applicable to the general type of rotary strainer which is exemplified in my copending application Serial No. 657,586, filed February 20th, 1933, now Patent No. 2,057,497, October 13, 1936.
In the drawings:
Figure 1 is a transverse sectional view of a rotary strainer showing the essential features of the strainer rotor and the casing therefor, with the improvement of the present invention applied thereto; and
Figure 2 is a side view of the mechanism of Figure 1, taken from the right of Figure 1 and having a portion of the casing removed to disclose internal parts.
The fluids or materials to be strained may be introduced into the strainer casing by means of the pipe 3, and after passing through the strainer rotor, as indicated by the arrows applied to Figure 1, the strained fluids are discharged and carried away through pipe 4. The inlet connection 3 is directly coupled to a fitting 5 which flares laterally as indicated in Figure 2 and which is in turn attached to the casing part 6. As will readily be seen from inspection of Figure 1, the casing has a generally annular cavity therein as indicated at l, in which the strainer designated ,a whole by the letter A is mounted. At the at side of the rotor the annular cavity communicates with the discharge fitting 8 which is similar to the inlet fitting 5.
The strainer casing, as in the copending application above referred to, is preferably split substantially diametrically of the strainer rotor and, in both figures, the numeral 6 has'been applied to the lower portion of the split casing. The upper portion is indicated by the numeral 9 in Figure 1, this portion being removed in the showing of Figure 2. Bearings l0 serve to support the rotor shaft H which may be driven in any convenient manner as by the gear diagrammatically indicated at l2. The rotor has a hub portion I3 splined to shaft II and secured in position against the abutment 14 by means of a collar I5. Packing glands [6 or the equivalent may be employed where the rotor shaft passes through the casing walls.
Projecting radially outwardly from the rotor hub l3 are a plurality of spokes I 1 between which strainer elements l8 are exposed for the passage therethrough of the fluid to be strained. The showing of the strainer elements between certain spokes in Figure 2 has been omitted merely for the sake of clarity, it being understood that these elements preferably appear between adjacent spokes throughout the entire strainer rotor. A peripheral ring 19 joins the outer ends of the spokes l1 and also serves to define the strainer pockets which are between the spokes. The strainer elements may be associated with the rotor hub I3 and peripheral ring IS in the manner illustrated in Figure l and these elements may be secured in position as by means of an additional spo-ked member 20 which is secured to the rotor by means of bolts 2|.
The strainer also includes clean on boxes 22 and 23 which are preferably constructed and arranged in accordance with my copending application above referred to. A detailed descrip tion of these parts is not reproduced herein since it is not believed necessary for a complete understanding of the present improvements. It should be understood, however, that the purpose of the clean-out boxes is to provide for counterflow of a cleaning liquid or fluid through the strainer ele ments. With this in view, inlet and outlet connections (the latter appearing at 24 in Figure 2) are extended, respectively, to the clean-out boxes 22 and 23 and these connections serve to admit a cleaning medium into the box 22 from which it passes transversely through the strainer pockets as they move between the boxes, after which the;
cleaning medium together with the materials removed from the strainer pockets passes into the outlet cleaning box 23 from which it is conducted away through the discharge connection 24.
Bearing in mind the foregoing description of the general nature of a rotary strainer of a type to which the present invention is applicable, attention is now directed to the following discussion of the features of improvement. Firstly, it is noted that it is of great importance to prevent leakage from the inlet to the'outlet side of the casing, i. e., from the inlet to the outlet side of the rotor, and this has been difiicult heretofore, especially where the fluid or liquid being strained is under relatively high pressure.
To this end I employ a novel sealing device arranged peripherally of the strainer casing and rotor. This device includes a peripheral ring 25 mounted in the casing and formed to provide a shoulder with which the yieldable or resilient ring 26 (carried by the rotor) contacts. In the preferred embodiment, the ring 25 is of metallic construction and the yieldable character of ring 26 is provided by forming it of any suitable resilient material such as rubber or some rubber compound. The latter ring (26) may be mounted on the strainer rotor in any convenient manner as by means of the flanges 2'! formed thereon and the attachment ring 28, the latter being secured to the peripheral ring H! by means of bolts 29 or the like.
From inspection of Figure 1 it will be seen that the rings 25 and 26 are relatively positioned to- Ward the outlet and inlet sides of the strainer casing. In other words, the ring 26 which is of resilient construction is mounted toward that side of ring 25 on which the fluid being strained enters the casing.
The rings are initially positioned so that their cooperating surfaces just contact. This is sufiicient to maintain an effective seal and separation of the chambers at opposite sides of the rotor when there is no appreciable drop in pressure from the inlet to the outlet side. The relative positions of the rings and the fact that one ring is yieldable toward and away from the other serves automatically to cause the seal to tighten when there is an appreciable pressure drop across the strainer. In fact, the tightness of the seal is determined by the pressure drop, so that the proper seal is provided under all conditions.
It is preferable in the construction described just above that the contacting surfaces of the rings 25 and 26 lie in a plane which is transverse or perpendicular to the rotor axis member I l. I have found that this effects a seal which, for practical purposes, is virtually perfect with respect to leakage from the inlet to the outlet sides and which affords the minimum possible friction under all pressure conditions. Still further I have found that the wearing qualities of this seal are far superior to those of other seals heretofore employed for the purpose.
Apparatus of the character described including a casing, a rotatable substantially disk-like device mounted in the casing in position to di vide the casing into a pair of chambers one located at each side of the plane of rotation of the device, and a sealing means for preventing fluid flow from one chamber to the other around the periphery of said device, said sealing means including a continuous yieldable ring carried by the rotatable device, and a cooperating rigid ring carried internally of the casing at that side of the yieldable ring which is presented toward the chamber to which it is desired to restrict fluid flow, the casing and said cooperating ring being split in a plane containing the axis of the rotatable device to provide for relative separation of easing parts.
DANIEL RAYMOND McNEAL.