GB2073603A

GB2073603A - Improvements in handling cement

Info

Publication number: GB2073603A
Application number: GB8110497A
Authority: GB
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1980-04-11
Filing date: 1981-04-03
Publication date: 1981-10-21

Abstract

Bagged cement is loaded onto a hopper (9) and feeds into cutter means (7) which comminutes the fabric of the cement bags. The cement and bag fragments are mixed with water in a mixer unit (2) and the mixture is pumped by pump (3) to a point of use, for example a pack in an underground mine. <IMAGE>

Description

SPECIFICATION Improvements in handling cement This invention concerns improvements in handling cement, more especially it concerns the handling of bagged cement.

It is well known to pump flowable cementitious material in underground coal mines to form a supportive concrete-like mass or "pack" which is effective in protecting rodaways from excessive strata forces. This application is known as pump packing.

The concrete-like packs are formed consecutively as the mine roadway advances, and quite large quantities of cement can be used during periods of rapid advance. Although cement may be taken underground in bulk containers, it is often very much more convenient from consideration of transport, etc. to use bagged cement. The cement bags are slit open and emptied into a hopper which feeds into a mixer unit in which water is added to form a flowable cementitious mixture, or emptied directly into a mixer unit. The emptied bags cause a disposal problem, since they quickly amass and can be a fire risk and thus have to be transported through the mine then carried to ground level. Furthermore, the slitting of the bags, which is done manually, is unpleasant and the cemnt dust irritates the skin and lungs.

The present invention therefore provides a method of preparing a hydraulic cement mix comprising feeding bagged cement into cutter means which comminutes the fabric of the bag and mixing the cementitious feed with water.

The invention also provides an apparatus for preparing a hydraulic cement mix comprising cutter means capable of comminuting the fabric of the bag of bagged cement and mixing means to mix the resulting cementitious feed with water.

The invention further provides a method of preparing a body of cementitious material comprising feeding bagged cement into cutter means which comminutes the fabric of the bag, mixing the resulting cementitious material with water to form a flowable mixture, and pumping the flowable mixture into a volume at least partially defined by shuttering.

The cutter means of the invention may be any suitble for the duty required, but it is preferably a multi-bladed cutter such as the "Muncher" which is marketed by Mono Pumps (Engineering) Limited of Mono House, Sekforde Street, Clerkenwell Green, London, EC1R OHE as a sewage sludge macerator.

The mixing means is preferably a conventional mixer such as a screw mixer, which is capable of feeding theflowable mixture to a pump.

Suitably, a hopper is mounted above the cutter means. The hopper may have a lid to reduce dust nuisance during operation. Alternatively, feeding means may be mounted above the cutter means, whereby bagged cement may be fed to the cutter means. Preferably such a feeding means is so shaped, for example is curved, that a bag of cement can fall or slide to the cutter means, but it is physi cally impossible for an operator to reach the cutter means.

Ordinary Portland Cement, accelerated portland cement or gypsum in bags may be used as the cement, and the term "cement" is to be understood as broadly covering all inorganic hydraulic cements.

The fabric of the bag may be any conventional material such as paper, reinforced paper, plastic film or woven or non-woven fabric.

While in the use of the present invention for pump packing underground, the cementitious feed is mixed with water and then at the point of use mixed with aggregate, possibly including run-of-mine coal, and optionally mixed with accelerator, it is to be understood that the invention can be used in the case of mixing such other components of a cement or concrete mix in the mixer.

The invention will now be described by way of example with reference to the accompanying drawing which represents an apparatus according to the invention.

Mounted on a skid frame base 1, is a chamber 2, containing a mixing and feed screw (not shown).

Attached to the chamber 2 is a wide throat cement feed pump 3, feeding a cement supply pipe 4; both the mixing and feed screw and the pump are driven by an electric motor 5, through a gearbox 6.

Mounted above the chamber 2 is cutting means 7, in this case a Mono "Muncher", is driven by a motor and gearbox unit 8. The "Muncher" 7 is fed from a loading hopper 9, into which is led a water supply pipe 10. A recycle of flowable cement mix from the pump to the hopper can be arranged by means of three-way valve 11 and pipe 12.

In use, bagged cement is loaded into the hopper, and water supplied through pipe 10. The muncher, mixer and pump are all set in motion and the cement and comminuted bag fragments are mixed with water and pumped out through pipe 4 to a roadside mixer unit (not shown) which mixes the flowable cement mixture with a mixture of aggregate held in suspension in bentonite solution and cement hardening accelerator. The resulting packing mixture is pumped into a roadside pack in known manner.

The present invention offers particular advantages underground, but it is believed applicable to any medium scale operation requiring mixed cement or concrete.

1. A method of preparing a hydraulic cement mix comprising feeding bagged cement into cutter means which comminutes the fabric of the bag and mixing the cementitious feed with water.

2. A method according to claim 1, wherein the cement is Ordinary Portland Cement, accelerated portland cement or gypsum.

3. A method according to claim 1 or 2, wherein the hydraulic cement mix is pumped after preparation to a point of use.

4. A method according to claim 1, substantially as hereinbefore described with reference to the accompanying drawing.

5. A method of preparing a body of cementitious material comprising feeding bagged cement into cutter means which comminutes the fabric of the bag, mixing the resulting cementitious material with water to form a flowable mixture, and pumping the flowable mixture into a volume at least partially

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in handling cement This invention concerns improvements in handling cement, more especially it concerns the handling of bagged cement. It is well known to pump flowable cementitious material in underground coal mines to form a supportive concrete-like mass or "pack" which is effective in protecting rodaways from excessive strata forces. This application is known as pump packing. The concrete-like packs are formed consecutively as the mine roadway advances, and quite large quantities of cement can be used during periods of rapid advance. Although cement may be taken underground in bulk containers, it is often very much more convenient from consideration of transport, etc. to use bagged cement. The cement bags are slit open and emptied into a hopper which feeds into a mixer unit in which water is added to form a flowable cementitious mixture, or emptied directly into a mixer unit. The emptied bags cause a disposal problem, since they quickly amass and can be a fire risk and thus have to be transported through the mine then carried to ground level. Furthermore, the slitting of the bags, which is done manually, is unpleasant and the cemnt dust irritates the skin and lungs. The present invention therefore provides a method of preparing a hydraulic cement mix comprising feeding bagged cement into cutter means which comminutes the fabric of the bag and mixing the cementitious feed with water. The invention also provides an apparatus for preparing a hydraulic cement mix comprising cutter means capable of comminuting the fabric of the bag of bagged cement and mixing means to mix the resulting cementitious feed with water. The invention further provides a method of preparing a body of cementitious material comprising feeding bagged cement into cutter means which comminutes the fabric of the bag, mixing the resulting cementitious material with water to form a flowable mixture, and pumping the flowable mixture into a volume at least partially defined by shuttering. The cutter means of the invention may be any suitble for the duty required, but it is preferably a multi-bladed cutter such as the "Muncher" which is marketed by Mono Pumps (Engineering) Limited of Mono House, Sekforde Street, Clerkenwell Green, London, EC1R OHE as a sewage sludge macerator. The mixing means is preferably a conventional mixer such as a screw mixer, which is capable of feeding theflowable mixture to a pump. Suitably, a hopper is mounted above the cutter means. The hopper may have a lid to reduce dust nuisance during operation. Alternatively, feeding means may be mounted above the cutter means, whereby bagged cement may be fed to the cutter means. Preferably such a feeding means is so shaped, for example is curved, that a bag of cement can fall or slide to the cutter means, but it is physi cally impossible for an operator to reach the cutter means. Ordinary Portland Cement, accelerated portland cement or gypsum in bags may be used as the cement, and the term "cement" is to be understood as broadly covering all inorganic hydraulic cements. The fabric of the bag may be any conventional material such as paper, reinforced paper, plastic film or woven or non-woven fabric. While in the use of the present invention for pump packing underground, the cementitious feed is mixed with water and then at the point of use mixed with aggregate, possibly including run-of-mine coal, and optionally mixed with accelerator, it is to be understood that the invention can be used in the case of mixing such other components of a cement or concrete mix in the mixer. The invention will now be described by way of example with reference to the accompanying drawing which represents an apparatus according to the invention. Mounted on a skid frame base 1, is a chamber 2, containing a mixing and feed screw (not shown). Attached to the chamber 2 is a wide throat cement feed pump 3, feeding a cement supply pipe 4; both the mixing and feed screw and the pump are driven by an electric motor 5, through a gearbox 6. Mounted above the chamber 2 is cutting means 7, in this case a Mono "Muncher", is driven by a motor and gearbox unit 8. The "Muncher" 7 is fed from a loading hopper 9, into which is led a water supply pipe 10. A recycle of flowable cement mix from the pump to the hopper can be arranged by means of three-way valve 11 and pipe 12. In use, bagged cement is loaded into the hopper, and water supplied through pipe 10. The muncher, mixer and pump are all set in motion and the cement and comminuted bag fragments are mixed with water and pumped out through pipe 4 to a roadside mixer unit (not shown) which mixes the flowable cement mixture with a mixture of aggregate held in suspension in bentonite solution and cement hardening accelerator. The resulting packing mixture is pumped into a roadside pack in known manner. The present invention offers particular advantages underground, but it is believed applicable to any medium scale operation requiring mixed cement or concrete. CLAIMS

5. A method of preparing a body of cementitious material comprising feeding bagged cement into cutter means which comminutes the fabric of the bag, mixing the resulting cementitious material with water to form a flowable mixture, and pumping the flowable mixture into a volume at least partially defined by shuttering.

6. A method according to claim 5, wherein the volume at least partially defined by shuttering is a pack in an underground mine.

7. A method according to claim 5 or 6, wherein the flowable mixture is admixed with aggregate and/or accelerating agent before it is pumped into the volume at least partially defined by shuttering.

8. An apparatus for preparing a hydraulic cement mix comprising cutter means capable of comminuting the fabric of the bag of bagged cement and mixing means to mix the resulting cementitious feed with water.

9. An apparatus according to claim 8, wherein the cutter means is a multi-bladed cutter.

10. An apparatus according to claim 8 or 9, wherein the mixing means is a screw mixer.

11. An apparatus according to claim 8,9 or 10, comprising also a pump for pumping the hydraulic cement mix.

12. An apparatus according to any of claims 8 to 11, comprising also a hopper mounted above the cutter means.

13. An apparatus according to any of claims 8 to 11, comprising also feeding means mounted above the cutter means.

14. An apparatus according to claim 13, wherein the feeding means is so shaped that a bag of cement can fall or slide to the cutter means, but it is physicallyimpossible for an operator to reach the cutter means during operation.

15. An-apparatus according to claim 8, substantially as hereinbefore described with reference to the accompanying drawing.