US2804272A - Apparatus for reducing the oversized material in the suction line of a dredge - Google Patents

Description

my Y m .u V m gm mi m 1 1 m Y w B g- 1957 w. T. s. MONTGOMERY APPARATUS FOR REDUCING THE OVERSIZED MATERIAL IN THE SUCTION LINE OF A DREDGE Filed Feb. 4, 1954 ATTORNEYS r. 2,804,272 Patented Aug. 27, 1957 APPARATUS FOR REDUCING THE OVERSIZED MATERIAL IN THE SUCTION LINE F A DREDGE William T. S. Montgomery, Jacksonville, Fla.

Application February 4, 1954, Serial No. 408,110

3 Claims. (Cl. 241-81) This invention relates to materials handling apparatus and more particularly to apparatus for handling materials entrained in a fluid stream as in dredging operations.

In such operations material is sucked from the bottom of a body of water through a conduit system by a dredge pump. While such dredge pumps are necessarily designed for heavy duty and are capable of handling quantities of grit, sand, rocks and pieces of wood without damage, materials such as stumps, and large rocks are often entrained in the stream which are beyond the capacity of the pump and cause excessive wear and damage to the pump or plug the pump, necessitating shutting down the operation. The pump may plug with such frequency as to render profitable operation impossible.

It is impractical to screen the inlet'pipe because of similar clogging problems.

Accordingly, it has been proposed to introduce a mechanism into the conduit system ahead of the dredge pump for separating oversize material from the fluid stream and for crushing the material to a size within the capacity of the pump before it is delivered to the inlet of the pump. It is with improvements in such apparatus that the present invention is primarily concerned.

Specifically, it has been discovered that despite the rugged construction of available crushing mechanisms they are subject to accelerated wear and require increased maintenance when they are operated directly in the fluid stream in an environment of Water, sand and grit as opposed to their normal environment of air.

It is accordingly the major purpose and object of the present invention to provide novel materials handling apparatus for reducing the size of materials entrained in a fluid stream including means for assuring operation of the material reducing means in air to thereby reduce Wear and maintenance cost.

It is .a more specific object to provide novel materials handling apparatus including crushing means located in a conduit which includes novel vent means operative to maintain the water level in the conduit below the level of the crushing means.

Other objects will become apparent as the description proceeds in connection with the drawings in which the single figure is a semi-diagrammatic vertical section of a preferred form of apparatus embodying the present invention.

Referring now more particularly to the drawings, the mechanism of the present invention is enclosed in a housing indicated generally at connected at one end to a conduit 12 leading to the inlet of a dredge pump (not shown) and at its other end to a conduit 14 leading to a material source, in the present case the bottom of a body of Water. The housing 10 thus forms an enlargement in the normal conduit system comprising conduits l2 and 14 and the suction established by the dredge pump tends to fill the housing with the material supplied through conduit 12.

The housing 10 comprises a substantially flat bottom member 16, front and rear members 18 and 20, a top 22 and side Wall members 24 which together with auxiliary top and bottom members 26 and 28, respectively, form a substantially air and water tight enclosure. If desired a manhole cover 30 and door 32 may be provided to permit access to the interior of the enclosure for inspection and maintenance. The housing 10 and the dredge pump are normally mounted on a boat or on shore above the water level.

Mounted substantially above the level of the top of conduits 12 and 14 is a crushing mechanism indicated generally at 34 comprising a toothed rotor 36 and a stator blade assembly 38. The crushing mechanism per se forms no part of the present invention and is preferably of the type disclosed and claimed in copending application Serial No. 362,790, filed June 19, 1953, forWood Reduction and Handling.

A continuous screen conveyor 40 travels over upper and lower sprockets 42 and 43, respectively, mounted and driven by any suitable means, not shown. The conveyor 4% is of very coarse mesh for example having a four inch grid so that it will permit a free flow of water, sand and small pieces of wood, etc. through the enclosure 10 from the inlet 14 to the outlet 12. In practice the mesh of the screen 40 will be determined by the capacity and material handling characteristics of the dredge pump. Material too large to pass through the screen 40 is carried by the conveyor and delivered to the crushing mechanism 34 through a throat formed by an extension 44 of the top member 22 and a member 46, the lower portion of which encircles the crusher rotor. The crusher 34 reduces the material in the manner set forth in the aforesaid copending application until it is of sufficiently small size to pass through the perforations in the member 46 whence it passes through the conduit 12 to the dredge pump. A substantially cylindrical guard 48 may be provided at the upper end of the retainer to assure proper stripping of material from the conveyor chain. Since all of the material entering the closure through conduit 14 is intercepted by the conveyor 40 all of the material exiting from the enclosure 1i! through the conduit 12 is necessarily of the required fineness since it either passes through the conveyor or is acted on by crusher mechanism.

While the mechanism thus far described has worked very satisfactorily in practice nevertheless it has been found that with the housing 19 substantially completely filled with water above the level of the crusher mecha nism the crusher is subject to excessive wear and requires frequent maintenance and inspection. In accordance with the present invention these difficulties are overcome by the provision of means for assuring the maintenance of the water level Within the housing 16 below the crusher rotor 36. This means comprises the vent assembly indicated generally at 50 which includes a float chamber 51 suitably supported on the housing and connected to the interior of the housing through upper and lower conduits 52 and 54 respectively. The upper portion of the housing 52 is provided with a vent pipe 58 adapted to be selectively opened or closed by a valve member 66 attached to a valve stem 62, the lower end or" which is connected to a float 64.

The float chamber and float are so dimensioned that the float 64 is disposed below the level of the crusher rotor 36 when the valve element 60 closes the opening 58. When the level of fluid within the housing 10 rises above the normal float level, the float and the valve element 60 are raised permitting air to enter the housing 10 through the opening 58 and the conduit 54. The entrance of air into the housing continues until the water is again reduced to its desired level indicated by the reference line W at which time the valve closes. Thus regardless of the flow conditions through the housing it) established by the dredge pump the liquid cannot rise to the level of the crusher assembly. Consequently, the crusher at all times operates in air and is not subject to the abrasive action of fluid, sand and grit and accordingly has an extended service life and requires reduced maintenance.

The invention may be embodiedin other specific. forms without departing from the spirit or essential character: istics thereof. The present embodiment is therefore to be conisdered in all respects as illustrative and not restric tive, the scope of the invention being indicated by the appended claims rather than by the foregoing, description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patentis:

1. Apparatus forreducing oversized material in the suction line of a dredge comprising a substantially air tight housing having an inlet, for water and material and an outlet connected to a source of suction, a valve in said housing, means for controlling said valve to maintain water in said housing at a predetermined level, material breaking means mounted in said housing above the level of the water, conveyor means in said housing for tending from below said inlet to a point above said breaking means and extending from one side of the housing to the other, for conveying material to said breaking means, said belt having openings to permit the passage of water and material below a predeterminedv size whereby only oversize material is carried by said belt to said breaking means, and means for driving said conveyor belt.

3. Apparatus for reducing oversized material in the suction line of a dredge comprising a substantially air conveying material to said breaking means, said conveyor water in said housing at a predetermined level, material breaking means mounted in said housing above the level of the water, a conveyor belt within said housing and extight housing having an inlet for Water and material and an outlet connected to a source of suction for drawing water and suspended material through said housing, an air valve in said housing, means for controlling said valve to maintain water in said housing at a predetermined level, a rotary breaker within and extending across said housing above the level of the water, inclined conveyor means extending across said housing and from the bottom of said housing to a point above said breaker for conveying material to said breaker, said conveyor means having openings to permit the passage of water and material below a predetermined size whereby only oversize material is conveyed to said breaker, means for actuating said conveyor means, and means for returning-material broken in said breaker to the water. i

References Cited in the file of this patent UNITED STATES PATENTS 1,235,672 Fitch et a1 Aug. 7, 1917 1,465,863 Pioda Aug. 21, 1923 2,106,851 Nordell Feb. 1, 1938 2,317,416 Stanley Apr. 27, 1943 2,446,772 Laughlin Aug. 10, 1948 FOREIGN PATENTS 894,980 1 Germany Oct.29, 1953

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