JPS597505B2 - Pressure relief device for rotating crusher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure relief device for use with a gyratory crusher having a crushing cone that is vertically adjusted by a hydraulic fluid assembly to control the size of the crushing gap.

A gyratory crusher with a hydraulically supported crushing cone is known in the art, for example from US Pat. No. 3,801,026 (1974).

A pressure relief device comprising a hydraulic fluid assembly and an accumulator for receiving expelled hydraulic fluid is also known, for example from US Pat. No. 2,667,309 (1954).
Conventional liquid-pneumatic pressure relief devices consist of a single fluid assembly connected to one or more accumulators containing compressible gas-filled bladders.

The fluid assembly is preset to a predetermined pressure, and once this pressure limit is exceeded, a valve is opened to allow hydraulic fluid to flow to the accumulator, thereby compressing the gas bladder and causing pressure in the pressure relief fluid assembly. Increase pressure. When the pressure within the fracturing mechanism decreases, the relief valve is closed and the high pressure within the pressure relief fluid assembly expels hydraulic fluid from the accumulator and back to the fracturing cone support device by the regulating check valve. The crushing cone is then raised to the initial crushing gap position and normal operation continues. Problems often arise with this type of pressure relief device due to the shape of the crushing gap between the crushing cone and the surrounding outer crushing wall.

The gap is tapered and becomes narrower as material from the top falls between the fracturing cone and the surrounding wall. Therefore, the unbreakable foreign particles that increase the crushing pressure and activate the pressure relief device can only travel down a short distance, beyond which they cannot travel further between the crushing cone and the surrounding wall. This increases the fracturing pressure again and activates the pressure relief device, but the pressure relief device does not have enough time to recover from the first activation and is at a higher pressure than normal, so a higher pressure is required. become.
This sequence of conditions continues until the foreign material falls out of the crusher. Successive actuations of such a pressure relief device may occur 15 or more times, each time requiring a higher pressure than the previous one. As a result, both the crusher and the pressure relief device experience continuously higher pressure peaks, about three times per second, thus creating vibrations and increasingly higher stresses in the device. A key feature of the invention is the design of a pressure relief device for a hydraulically supported rotary crusher that does not create progressively higher pressure peaks when uncrushed foreign particles pass through. In particular, the present invention provides a pressure relief device for a rotary crusher, comprising (a) a first cavity under the central support shaft of the crushing cone, a hydraulic fluid chamber, and a position of the crushing cone; a first fluid assembly having a hydraulic fluid transfer device connecting the hydraulic fluid reservoir and the first cavity to vertically adjust the gap; a relief valve located below, the upper surface of which is located at the first
A relief valve in contact with the hydraulic fluid in the cavity, and (c)
a second cavity under the relief valve; an accumulator for applying a predetermined back pressure to the bottom surface of the relief valve;
a second fluid assembly having a connection device connecting the cavity and the accumulator; and a return discharge line communicating with the hydraulic fluid reservoir.

An advantage of the present invention is that non-friable foreign material can be easily passed through the shredder without the need for multiple continuous actuations of the pressure relief device. Furthermore, since the pressure relief valve is attached directly to the crusher without going through a pipeline, the response time to an increase in crushing pressure is faster. Further, with this pressure relief device, the pressure relief valve can be easily removed for maintenance of the crusher, and there is no need to remove heavy and difficult-to-remove pipes to repair the crushing mechanism. The following description will be made with reference to the accompanying drawings.

FIG. 1 shows a rotary crusher with a support wing consisting of a lower frame section 1 and an upper wing section 2. FIG.

An open-topped external fracture wall or recess 3 is supported within the upper section 2 . A crushing cone 4 is provided in the upper head section 2 and the outer crushing wall 3. crushing cone 4
is supported by a vertical shaft 5 having a longitudinal central axis inclined at a small angle with respect to the vertical central axis X-Y of the support rods 1,2. The lower part of the shaft 5 is supported in a cylindrical housing 7 by a bearing sleeve or liner 8. The housing 7 is rotatably supported by an internal top member 9 and a base portion 10. The structure of such a rotary crusher is well known in the art, and the gear and drive shaft mechanism for eccentrically rotating the shaft 5 and imparting a whirlwind motion to the crushing cone 4 is described, for example, in U.S. Pat. No. 3,813,047 ( (1974), so it will not be discussed in detail here.

The shaft 5 and the crushing cone 4 can be adjusted vertically by forcing the hydraulic fluid from the hydraulic fluid reservoir 13 by means of a pump 14 and through a line 15 into the cavity or cavity 12 below the piston 11. .

This results in a gap 6 between the crushing cone 4 and the outer crushing wall 3.
is adjusted to the required crushing size. If necessary, air or excess hydraulic fluid can be manually vented via extraction valve 16. FIG. 1 also schematically shows a pressure relief device consisting of a pressure relief valve 17 and two separate but interacting hydraulic fluid assemblies.

These assemblies are referred to herein as a fluid ejection assembly and a piston pressurization assembly and will be described in more detail below. Pressure relief valve 1
7 is the cavity 1 of the crusher, as shown in detail in Figure 2.
Can be installed directly under 2. (See FIG. 1) Top cover plate 18, housing 19 with cylindrical hole 20
, a relief piston or piston valve 11 vertically displaceable within a bore 20, an annular valve seat 22 forming the upper limit of movement of the piston valve, and a bottom cover plate 23. In this preferred embodiment, piston valve 2
The upper section 24 of 1 has a smaller diameter than the lower section 25, so that a circumferential edge 26 is formed where the sections 24, 25 join.

Such a difference in diameter causes the relief valve piston 21 to close to the valve seat 2.
2, the effective surface area of the top surface of the valve 21 is smaller than that of the bottom surface, and therefore, in order to equalize the upward force and downward force of the piston valve 21, In this case, the fluid pressure applied to the bottom surface of the piston valve 21 may be smaller than that to the top surface. However, piston valve 21
is pushed downward and away from the valve seat 22, the peripheral edge 26 comes under the action of the fluid above the piston valve 21, so that the effective surface area of the piston valve 21 receiving the downward pressure is reduced by the upward pressure. It is equal to the effective surface area of the bottom surface of the piston valve 21 that receives the water. The fluid discharge assembly includes a hydraulic fluid reservoir 1
3, a pump 14, a supply line 15 that supplies fluid from the tank 13 to the cavity 12, a cylindrical hole 20 connected to the manifold 28;
symmetrically spaced discharge ports 27 coupled to a pipe line 29 leading the discharged fluid to a surge tank 30;
It is comprised of a return discharge line 31 (schematically shown in FIG. 1) for conveying fluid discharged from the exhaust and surge tank 30 to the hydraulic fluid reservoir 13. In the preferred embodiment, the pipe line 29 has a peephole 32 for monitoring the flow rate and leakage through the piston valve 21, and a surge tank 30 has a peephole 32 for monitoring the flow rate and leakage through the piston valve 21, and a surge tank 30 for venting air that is displaced when fluid is entrained. It has a vent 33. The piston pressure assembly is
The cavity 34 on the lower side of the piston valve 21, the bottom cover
It consists of an access port 35 formed in the plate 23, a regulating check valve 36 that does not restrict the downward flow rate but adjusts the reverse flow rate, and a pipe line 37 to the abutment and the accumulator 38.

This pipe 37 could be a flexible medium or high pressure hose. The piston pressurization assembly also includes a coupling line 39 contained within the fluid force source, as shown schematically in FIG. The pressurization source, in this preferred embodiment, includes a hydraulic fluid valve 13, a pump 14, and two isolation valves 4 for providing fluid pressurization to the piston pressurization assembly to the required pressure.
0 and 41, a pressure gauge 42 for monitoring the pressure within the piston pressurization assembly, an extraction valve 43 for manually releasing air or excess fluid from the device, and an accumulator 38.
A second safety pressure relief valve 44 is provided in case the valve becomes clogged with fluid. The accumulator 38 is a conventional gas bag accumulator, and the safety valve 44 is also of a conventional type.

The operation of this novel pressure relief device under typical circumstances will now be described.

1, fluid pressurization of the viston pressurization assembly closes isolation valve 40, opens isolation valve 41, and pumps hydraulic fluid, such as oil, from line 15 and into line 15. 3
This is done by supplying the fluid to the piston pressurization assembly through 9 until the required relief pressure is reached. Valve 41 is then closed and valve 40 is opened to pump hydraulic fluid from reservoir 13 and through line 15 to piston 11.
By feeding the crushing cone 4 into the lower cavity 12, the crushing cone 4 is lifted into the required operating position. The crusher is thus ready for operation at any time. Also, the fluid supply to bring the piston assembly to the required pressure may be provided by a suitable gas rather than hydraulic fluid.

This can be done by any suitable method known in the art, such as by using a shutoff valve 41.
This could be done by closing the valve and supplying pre-compressed gas through extraction valve 43 to the piston pressurization assembly. Referring to FIG. 2, the pressure in the piston pressurizing circuit holds the piston valve 21 against the valve seat 22 with a force equal to the product of this pressure and the effective surface area of the bottom surface of the piston valve 21.

The downward force on piston valve 21 is equal to the product of the pressure of the hydraulic fluid in the air Pfrl2 below piston 11 (FIG. 1) and the effective surface area of the top surface of piston valve 21. When the downward force on piston valve 21 exceeds the upward force, piston valve 21 is pushed downward and the pressure relief device becomes operative. In FIG. 1, when an unbreakable piece enters the gap 6 between the crushing cone 4 and the outer crushing wall 3, the resulting increased force on the crushing cone 4 is directed downwardly through the shaft 5 and the piston 11 into the cavity 12. is transmitted to the hydraulic fluid within.

When the pressure of the hydraulic fluid in the cavity 12 increases and the downward force applied to the piston valve 21 exceeds the upward force applied to the piston valve by the pressure of the hydraulic fluid in the piston pressurizing circuit, the piston valve 21 is forced downwardly, where the fluid within the cavity 12 flows from the outlet 27 to the manifold 28.
and from there enters the surge tank 30 through the pipe line 29. In FIG. 1, when the fluid in the cavity 12 under the piston 11 is thus discharged through the pressure relief valve 17, the fracturing cone 4 moves downwardly and away from the outer fracturing wall 3 and thus hangs on the fracturing cone 4. The pressure is relieved, whereupon the unbreakable pieces in the gap 6 fall out and are able to exit the crushing chamber 6. FIG. 2 Ff - In addition, the downwardly moving piston valve 21 directs the hydraulic fluid in the cavity 34 below it to the check valve 36.
and through pipe line 37 to accumulator 38, resulting in an increased pressure of the hydraulic fluid within the piston pressurization assembly. However, as previously mentioned and seen in FIG. 2, the effective surface area of the top surface of the piston valve 21 when closed is less than that of the bottom surface. As a result, piston valve 2
The piston valve 21 will not be moved downwardly until the fluid pressure above the piston valve exceeds some value that is greater than the fluid pressure below it. As piston valve 21 is moved downwardly and open, peripheral portion 26 receives hydraulic fluid on the upper side of piston valve 21, so that the effective surface area of the top surface of piston valve 21 is equal to that of the bottom surface. However, the piston valve 21
The higher pressure on the upper side and the lower pressure on the lower side will be applied to their equal area surfaces, which will cause the piston valve 21 to be fully opened, whereupon the hydraulic fluid will be allowed to flow unrestricted from the cavity 12. You will be able to spit it out. Due to the ejection of fluid q from the cavity 12, the downward pressure on the piston valve 21 is reduced.

When the force on the bottom side of the piston valve 21 exceeds the force on the top side, oil is discharged from the accumulator 38, passed through the pipe line 37 and regulated in the check valve 36, so that the piston valve 21 Start moving upwards. The adjustment controls the rate of closure of piston valve 21 to provide adequate time for hydraulic fluid delivery and crushing cone descent to allow non-friable debris to exit through crushing chamber 6 (FIG. 1). In FIG. 1, fluid discharged from cavity 12 below piston 11 and directed to hydraulic fluid reservoir 13 as described above is controllably returned to cavity 12 by pump 14 and pipe line 15. It will be done.

The crushing cone 4 is thus raised to the previous operating position and normal operation continues. Pump 14 may be operated continuously, or a suitable fluid level monitor 45, such as a float in bath 13, may be used to activate pump 14 when a certain level of fluid is reached. . Importantly, the fluid discharge assembly and piston pressurization assembly work in unison to relieve excess pressure within the gyratory crusher;
These assemblies are completely separate mechanical systems. That is, as can be seen in FIG. 2, after the relief valve piston 21 has opened and hydraulic fluid has been discharged, the piston pressurization assembly returns the valve piston 21 to its original closed position relative to the valve seat 22 or closes the fracturing cone. 4 (FIG. 1) into its original operating position. As already mentioned, the required positioning of the crushing cone 4 is achieved by pumping fluid from the hydraulic fluid reservoir 13 through the pipe line 15 into the cavity 12 below the piston 11. .

[Brief explanation of the drawing]

FIG. 1 is an elevational view in vertical section of a part of a gyratory crusher with a novel pressure relief device according to the invention shown schematically;
FIG. 2 is a detailed vertical cross-sectional view of the pressure relief device. 1, 2...Crushing machine support holder, 3...Crushing wall, 4...Crushing cone, 5...Shaft, 6
......Crushing gap, 11...Piston, 1
2...Void, 13...Hydraulic Fluid Monk, 1
4... Pump, 15... Fluid supply line, 17... Pressure relief valve, 19... Housing, 20... Hole, 21 ...Valve piston, 22... Valve seat, 24, 25...
・Valve piston upper and lower sections, 26...peripheral section, 27...discharge port, 28...manifold, 29...pipe line, 30...・・・
・Surge tank, 31...Return discharge line,
34...Cavity, 36...Adjustment check valve, 37...Pipe line, 38...
...Accumulation unit, 39...Connection line, 4
0,41...Shutoff valve, 45...Fluid level monitor.

Claims (1)

Claims: 1. A rotating crusher having a fixed outer crushing wall and a rotating inner crushing cone mounted on a vertically adjustable central support shaft and spaced an adjustable gap from the crushing wall. (a) for vertically adjusting the first cavity under the central support shaft of the crushing cone, the hydraulic fluid reservoir, the position of the crushing cone, and the gap; a first fluid assembly having a hydraulic fluid transfer device connecting the hydraulic fluid and the first cavity;
(b) a relief valve located below the first cavity, the upper surface of which is in contact with the hydraulic fluid in the first cavity; (c) a second cavity located below the relief valve; , (d) a second fluid assembly having an accumulator for applying a predetermined back pressure to a bottom surface of the relief valve, and a connecting device connecting the second cavity and the accumulator; A discharge line that communicates with the first cavity through a discharge port that opens when displaced toward the second cavity, and further includes a return discharge line that communicates with the hydraulic fluid tank. pressure relief device. 2. The pressure relief device of claim 1, wherein the upper portion of the relief valve piston has a smaller diameter than the lower portion, so that when the valve piston is closed, its top surface has a smaller effective surface area than its bottom surface. A pressure relief device comprising: 3. The pressure relief device according to claim 1 or 2, wherein the hydraulic fluid transfer device includes a hydraulic fluid reservoir, and a hydraulic fluid from the reservoir to the cavity below the crushing cone center support shaft. a pump and supply line for supplying the relief valve, a discharge port for discharging hydraulic fluid from the cavity when the relief valve piston opens, a manifold, and a pipe line for conveying the discharge fluid from the manifold to the hydraulic reservoir. A pressure relief device comprising: 4. The pressure relief device of claim 3, comprising: a discharge fluid pipe line connecting the manifold to a surge tank; and a return drain line connecting the surge tank to the hydraulic fluid reservoir. A pressure relief device comprising: 5. In the pressure relief device according to claim 3, a fluid level is provided in the hydraulic fluid tank in order to return the fluid discharged from the hydraulic fluid tank to a cavity below the crushing cone center support shaft. A pressure relief device characterized by being equipped with a monitor. 6. The pressure relief device of claim 3, wherein the second fluid assembly comprises a cavity in the underside of the relief valve piston, a regulating check valve separating the cavity from a pipeline; and the pipe line connected to an accumulator. 7. The pressure relief device according to claim 6, wherein the pipe line connected to the accumulator comprises a flexible hose. 8. The pressure relief device of claim 6, wherein the fluid in the second fluid assembly is a suitable liquid such as oil. 9. The pressure relief device of claim 6, wherein the fluid in the second fluid assembly is a gas suitable as a pressure transmission medium.