AU2012100467A4 - A batch waste water submergible evaporative apparatus - Google Patents

Abstract

A batch waste or produced water submergible evaporative apparatus for processing waste or 5 produced water containing dissolved solids and impurities wherein by utilising a singular or plurality of tanks, whereby waste or produced water and precipitants can be disposed of in a batch process. A method of use of the apparatus. -11 - -IQ 0*

Description

INNOVATION PATENT APPLICATION A BATCH WASTE WATER SUBMERGIBLE EVAPORATIVE APPARATUS FIELD OF THE INVENTION 5 This invention relates to the mining industry, in particular but not limited primarily to a batch waste water submergible evaporative apparatus for separating and removing dissolved solids, typically mineral salts, from waste or produced water in the coal seam gas industry. In addition, the invention relates to the disposal of concentrated brine streams from reverse osmosis plants processing waste water, the disposal of mining activity (including fractionation) related water 10 and chemical disposal, and may also be applied to other industries where waste waters need to be minimised or disposed. BACKGROUND ART 15 In the oil drilling and coal seam gas industries, the disposal of waste water containing impurities, dissolved salts and possibly toxic particulate mineral or crystalline matter is a problem. A less environmentally friendly prior art solution is to pump the waste water into large evaporative pools. This process relies on ambient weather conditions to evaporate the water 20 over time and can have disastrous consequences where waste water overflow or seepage into surrounding agricultural land can occur. Evaporative ponds require considerable capital outlay and are fixed in location. They can be highly inefficient in wet weather conditions. In addition, once the water has evaporated, the remaining sludge of solid waste matter still has to be disposed of. This requires the use of additional machinery and transport to waste disposal sites 25 which add further to the costs. Occupancy of valuable farming land by drilling rigs and on-site evaporative ponds or tanks has caused divisions between competing agricultural and mining interests and their respective protagonists and supporters. These factors have led to the development of mobile or portable waste water processing and 30 evaporative plants. One popular prior art system involves the utilisation of submerged combustion plants and devices to evaporate or vaporise water containing dissolved solids. In - 1 most examples, the prior art involves submerging a device dispensing hot gases into the waste water to vaporise the water leaving a sludge of solid material which must then be pumped out of the tank for disposal. In some cases the water component is recovered as potable water but is mostly allowed to evaporate into the atmosphere. Examples of the prior art hereinabove 5 mentioned is disclosed in US20110303367A1 and CA2751895A1. In most prior art examples, salt deposits build up inside the tanks and in the pumps over time and result in down time required to descale and service the equipment. Crystalline and mineral precipitates are often hard to remove and extremely abrasive to moving parts resulting in extreme wear and tear on the pump or other sludge transport mechanisms. 10 Produced water from mining operations has been a problem by-product which needs an acceptable method of disposal. However, produced water from coal seam gas wells typically contains high levels of salts, carbonates, iron, coal fines and other impurities making it unsuitable for direct disposal to grade. A proposal has been suggested in which these waste 15 waters and mining related waters may be purified by reverse osmosis prior to discharge. This reverse osmosis process produces a concentrated reject stream of brine, solids, chemicals and other impurities which require disposal. A proposal has been submitted by which produced waters from coal seam gas wells are ?0 evaporated using a range of techniques and systems. These methods are usually non-portable, only produce concentrated brines which require further treatment, are susceptible to lengthy manual cleaning and downtime, as well as being unable to cope with the volumes of produced water or waste water. 25 OBJECT OF THE INVENTION It is an object of the invention to provide a novel and innovative solution to the limitations and disadvantages of the prior art. Specifically the present invention aims to provide process waste water and mining associated liquids disposal system which alleviates one or more of the problems associated with above mentioned disposal systems. Other aims and advantages of the 30 invention may become apparent from the following description. -2- STATEMENT OF THE INVENTION In one aspect the invention resides in a batch waste water submergible evaporative apparatus including in combination: 5 one or more batch processing tanks for processing the waste water containing dissolved solids; water delivery means which maintains liquid level in the tank a submergible sparger having a plurality of nozzles ; sparger submersion means adapted to raise and lower the sparger into the tank; 10 heating means adapted to heat gas supplied to the sparger, and pressuring means adapted to elevate pressure of the heated gas in the sparger for delivery to the nozzles, wherein in operation, the sparger is submerged in the liquid in the tank, wherein bubbles of hot gas escaping the 15 nozzles cause vaporisation of the water and precipitated solid matter to be deposited in the tank and wherein as the liquid is depleted, the level is continually maintained by the water delivery means until the solids are deposited to a predetermined level which completes a processing cycle wherein the sparger is raised and the tank replaced with another tank containing a fresh batch of wastewater delivered by the water delivery means and the sparger 20 resubmerged to commence another processing cycle wherein in effect, by utilising a plurality of tanks, waste water and mineral precipitants can be disposed of in a batch process. Preferably, the water delivery means includes gravity fed and/or positive pressure collection means, typically pump means adapted to collect waste water from an existing gathering system 25 or pond. Preferably, there is water collection and condensing means for recovery of evaporated water as potable water or a clean water by product. 30 Preferably the heating means is a submergible combustion burner using coal seam gas, natural gas, liquefied petroleum gas or other combustion fuel sources to heat the gas in the sparger. -3- Preferably the tanks are removable bins or may have liners which are disposed along with the solidified contaminants. 5 In the alternative, the tanks are reused after being cleaned of the solid contaminants which are disposed of separately. In the preferred example, the apparatus may be a skid mounted portable system and/or may be housed in a compartment such as a shipping container or is truck-mounted. 10 Preferably, the combustion of fuel in the heating means is controlled by a burner management system which controls the evaporation rate by monitoring the available gas supply pressure of the pressuring means and the level of the liquid in the tank. 15 Preferably there are included an auto-ignition system and flame and temperature monitoring means associated with the combination of fuel by the heating means. Preferably the pressuring means is an electric air blower or compressor. 20 Preferably the sparger submersion means is an articulated frame that includes hydraulic or pneumatic rams to lift and pivot the frame in an accurate path to raise and lower the sparger. Preferably, the tanks are placed and removed by means of a forklift, however other means including electrical conveyor belt, crane, or any other machinery or means may be used. 25 Preferably there is included a diesel generator, gas fired generator or a micro turbine to provide electrical power to the air blower, control systems or any other integrated equipment. In another aspect, the invention resides in a method of batch processing of waste or produced water 30 using the submergible evaporative apparatus as hereinabove defined and described including the steps of: -4a. collecting and delivery of waste or produced water to the one or more of the batch tanks; b. locating the batch tank in the apparatus; c. submerging the sparger in the liquid in the tank; 5 d. vaporising the water component and leaving behind the mineral and salt contaminants as a brine slurry or sludge or solid; e. maintaining the level of liquid in the tank until a predetermined level of solids have been deposited which completes an evaporative cycle; f. on completion of the evaporative cycle, raising the sparger; 10 g. removing the tank containing the sludge, and h. replacing the tank-with another tank containing a fresh batch of waste water to be likewise processed, and i repeating the process as is necessary. 15 The tank and hot gas delivery piping can be insulated or lagged in order to increase the efficiency of the system BRIEF DESCRIPTION OF DRAWINGS In order that the invention be more readily understood and put into practical effect, reference 20 will now be made to the accompanying drawings wherein: Figure 1 shows a preferred apparatus according to the invention. DETAILED DESCRIPTION OF THE INVENTION 25 Referring to Figure 1, there is shown a preferred submergible batch waste water processing evaporation apparatus according to the invention. The apparatus as hereinbefore defined includes a removable batch tank 10 for holding collected waste water delivered to the tank. The water level in the tank is maintained by water delivery -5pipe 11. The sparger 12 comprising a hollow manifold having a plurality of spaced nozzles is submerged into the liquid in the tank by means of an articulated frame 14. Heated gas from a combustion source 19 is fed into the sparger 12 via hollow frame member or 5 pipe 16. The air pressure in the sparger is elevated by the blower 18 so that hot gas heated by the combustion burner 19 is delivered to the liquid in the form of bubbles via the nozzles of the sparger. 10 As the water is continually replenished and evaporated leaving behind a predetermined quantity of solid containments, the process can be stopped. The sparger 12 is then raised out of the tank by lifting the frame directly upwards via the 15 hydraulic rams 23, 25, 27, 28 and articulating the frame via the hydraulic rams 20, 22 in the direction of arrows 24, 26. The tank can then be removed for transportation or cleaning or disposed together with the precipitated salt and mineral waste as a complete unit. Another tank can then be positioned under the sparger 12, filled with waste water and the sparger 12 lowered to batch process the liquid in the same manner. It will be obvious that the water 20 vaporised can be recovered as potable water or clean water by product. This may involve placing a sealing lid (not shown) over the batch tank wherein water vapour can be captured and condensed as a liquid distillate. The tank and hot gas delivery piping can be insulated or lagged in order to increase the 25 efficiency of the system. -6- VARIATIONS It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of 5 this invention as is herein set forth. In the specification the terms "comprising" and "containing" shall be understood to have a broad meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer orastep or group of integers or steps but not the exclusion of any other integer or 10 step or group of integers or steps. This definition also applies to variations on the terms "comprising" and "containing" such as "comprise", "comprises", "contain" and "contains". The term, "waste water" shall be understood to include and refer also to "mining waste water", "exploration waste water", "produced water", "formation water", "drilling water", "coal seam gas waste water" or any other waste water containing dissolved solids or any other impurities. 15 20 25 -7-

Claims (11)

1. A batch waste water submergible evaporative apparatus including in combination: 5 one or more batch processing tanks for processing the waste water containing dissolved solids; water delivery means which maintains liquid level in the tank a submergible sparger having a plurality of nozzles ; sparger submersion means adapted to raise and lower the sparger into the tank; 10 heating means adapted to heat gas supplied to the sparger, and pressuring means adapted to elevate pressure of the heated gas in the sparger for delivery to the nozzles, wherein in operation, the sparger is submerged in the liquid in the tank, wherein bubbles of hot gas escaping the 15 nozzles cause vaporisation of the water and precipitated solid matter to be deposited in the tank and wherein as the liquid is depleted, the level is continually maintained by the water delivery means until the solids are deposited to a predetermined level which completes a processing cycle wherein the sparger is raised and the tank replaced with another tank to be filled with a fresh batch of wastewater delivered by the water delivery means, and the sparger 20 resubmerged to commence another processing cycle wherein in effect, by utilising a plurality of tanks, waste water and mineral precipitants can be disposed of in a batch process.

2. The apparatus of Claim 1 wherein the water delivery means includes gravity fed and/or positive pressure collection means, typically pump means adapted to collect waste water from an existing 25 gathering system or pond.

3. The apparatus of any of the above claims wherein there is water collection and condensing means for recovery of evaporated water as potable water or a clean water by product. 30 4. The apparatus of any of the above claims wherein the heating means is a submergible combustion burner using coal seam gas, natural gas, liquefied petroleum gas or other combustion fuel sources to heat the gas in the spa rger. -8-

5. The apparatus of any of the above claims wherein the tanks are removable bins or have liners which are disposed along with the solidified contaminants.

6. The apparatus of any of Claims 1 to 4 wherein the tanks are reused after being cleaned of the solid 5 contaminants which are disposed of separately.

7. The apparatus of any of the above claims wherein the apparatus is skid mounted and portable and/or is housed in a compartment such as a shipping container or is truck-mounted. 10 8. The apparatus of any of the above claims wherein the combustion of fuel in the heating means is controlled by a burner management system which controls the evaporation rate by monitoring the available gas supply pressure of the pressuring means and the level of the liquid in the tank.

9. The apparatus of any of the above claims wherein there are included an auto-ignition system and 15 flame and temperature monitoring means associated with the combination of fuel by the heating means.

10. The apparatus of any of the above claims wherein the pressuring means is an air blower or compressor. 20

12. The apparatus of any of the above claims wherein the sparger supporting means is an articulated frame that includes hydraulic or pneumatic rams to lift and pivot the frame in an accurate path to raise and lower the sparger. 25 13. The apparatus of any of the above claims wherein the tanks are placed and removed by means of a forklift, or other means including electrical conveyor belt, or crane or other machinery or any other means.

14. The apparatus of any of the above claims wherein there is included a gas fired generator or diesel 30 generator or a micro turbine to provide electrical power to the air blower, control systems or any other integrated equipment. -9-

15. The apparatus of any of the above claims wherein the tank and hot gas delivery piping is insulated or lagged in order to increase the efficiency of the system. 5 16. A method of batch processing of waste or produced water using the submergible evaporative apparatus as hereinabove defined and described including the steps of: j. collecting and delivery of waste or produced water to one or more of the batch tanks; k. locating the batch tank in the apparatus; 10 1. submerging the sparger in the liquid in the tank; m. vaporising the water component and leaving behind the mineral and salt contaminants as a brine, slurry, sludge or solid; n. maintaining the level of liquid in the tank until a predetermined level of solids have been deposited which completes an evaporative cycle; 15 o. on completion of the evaporative cycle, raising the sparger; p. removing the tank containing the sludge, and q. replacing the tank with another tank, then filling the tank with a fresh batch of waste or produced water to be likewise processed, and r. repeating the process as is necessary. 0