Material Mixing System

Abstract

The invention relates generally to a mixing system for mixing a dry material with a liquid. The mixing system includes a supply of dry material and a supply of liquid. An infinitely variable metering device meters the dry material into the liquid. A sensor senses the ratio of dry material to liquid. The sensor is operatively connected to the metering device to control the metering device to obtain a desired ratio of dry material to liquid. The dry material is dispensed volumetrically by volume of liquid to form the desired ratio of dry material to liquid.

Claims

1. A mixing system for mixing a dry material to a liquid, said mixing system comprising: a supply of dry additive; a supply of material; a variable metering device for metering said dry material to said liquid; a sensor for sensing the ratio of material to liquid, said sensor being operatively connected to said metering device to control said metering device to obtain a desired ratio of dry material to liquid; whereby said dry material is dispensed volumetrically by volume of liquid to form said desired ratio of dry material to liquid.

2. The mixing system of claim 1, wherein said metering device includes a shaft and a plurality of fingers extending radially outwardly from said shaft, said fingers sweeping dry material from said dry material supply.

3. The mixing system of claim 1, a mixing bowl having at least one inlet for receiving liquid from said supply of liquid, said dry material being fed into said mixing bowl to mix with said liquid, said mixing bowl having an outlet adapted to discharge the mixed dry material and liquid.

4. The mixing system of claim 1, further including a dry material conditioner said dry material conditioner being adapted to receive said dry material from said metering device, said dry material conditioner conditioning the dry material to form conditioned dry material.

5. The mixing system of claim 1, further including a hopper to contain said supply of dry material, said hopper having a first opening for receiving said supply of dry material and a second opening for discharging said supply of dry material.

6. The mixing system of claim 1, further including a motor operatively connected to said metering device and a controller operatively connected to said motor, said controller being operatively connected to said sensor for controlling said motor to obtain a desired ratio of dry material to liquid.

7. The mixing system of claim 1, wherein said dry material is salt.

8. The mixing system of claim 1, wherein said liquid is water.

9. The mixing system of claim 3, wherein said mixing bowl has a round cross section and a conical lower portion.

10. The mixing system of claim 9, wherein said mixing bowl includes a plurality of nozzles to facilitate mixing.

11. A method for producing a liquid de-icer comprising the steps of: providing a hopper adapted to contain a quantity of bulk de-icing material, said hopper having a first opening for receiving bulk de-icing material and a second opening for discharging bulk de-icing material; adding a bulk de-icing material to said hopper; providing a metering unit positioned adjacent said second opening; discharging bulk de-icing material from said hopper into said metering unit, metering through said metering unit said bulk de-icing material from said hopper; providing a bulk de-icing material conditioner to receive bulk de-icing material from said metering unit, discharging bulk de-icing material from said metering unit into said bulk de-icing material conditioner, conditioning the bulk de-icing material through said conditioner to form conditioned bulk de-icing material; providing a mixing bowl having at least one water inlet, supplying water through said water inlet to said mixing bowl, feeding said conditioned bulk de-icing material into said mixing bowl to mix with said water to form liquid de-icer, said mixing bowl having an outlet adapted to discharge the liquid de-icer; initiating a startup step to start the production of liquid de-icer, said startup step initiating water supply to said mixing bowl and initiating the metering unit and the de-icing conditioner to feed a greater percentage of conditioned de-icing material to said mixing bowl than is required to produce a pre-determined discharge ratio of conditioned bulk de-icing material for a first period of time to create a conditioned de-icing material reserve in the bottom of the mixing bowl, controlling said water supply, metering unit and de-icing conditioner after said start up step to continuously produce liquid de-icer at pre-determined discharge ratio of conditioned de-icing material and water.

12. The method for producing a liquid de-icer of claim 11 further including a cleanup mode including the steps: a. stopping the metering unit and de-icing conditioner; b. circulating the liquid de-icer within the mixing bowl until the ratio of de-icing material to water is above the discharge ratio; c. supplying water to said mixing bowl after step b until said ratio of de-icing material to water is lower than said discharge ratio; d. repeating steps b and c until said ratio of de-icing material to water remains below said discharge ratio; e. stopping the supply of water and circulation after step d; f. rinsing out said mixing bowl.

13. A method for producing a liquid de-icer comprising the steps of: providing a hopper adapted to contain a quantity of bulk de-icing material, said hopper having a first opening for receiving bulk de-icing material and a second opening for discharging bulk de-icing material; adding a bulk de-icing material to said hopper; providing a metering unit positioned adjacent said second opening; discharging bulk de-icing material from said hopper into said metering unit, metering through said metering unit said bulk de-icing material from said hopper; providing a bulk de-icing material conditioner to receive bulk de-icing material from said metering unit, discharging bulk de-icing material from said metering unit into said bulk de-icing material conditioner, conditioning the bulk de-icing material through said conditioner to form conditioned bulk de-icing material; providing a mixing bowl having at least one water inlet, supplying water through said water inlet to said mixing bowl, feeding said conditioned bulk de-icing material into said mixing bowl to mix with said water to form liquid de-icer, said mixing bowl having an outlet adapted to discharge the liquid de-icer; controlling said water supply, metering unit and de-icing conditioner after said start up step to continuously produce liquid de-icer at a pre-determined discharge ratio of conditioned de-icing material and water; initiating a cleanup mode to clean the mixing bowl, said mode including; a. stopping the metering unit and de-icing conditioner; b. circulating the liquid de-icer within the mixing bowl until the ratio of de-icing material to water is above the discharge ratio; c. supplying water to said mixing bowl after step b until said ratio of de-icing material to water is lower than said discharge ratio; d. repeating steps b and c until said ratio of de-icing material to water remains below said discharge ratio; e. stopping the supply of water and circulation after step d; f. rinsing out said mixing bowl.

13. The method for producing a liquid de-icer of claim 12 further including a startup mode, said start up mode including the steps: f. initiating water supply to said mixing bowl and initiating said metering unit and said de-icing conditioner to feed a greater percentage of conditioned de-icing material to said mixing bowl than is required to produce said pre-determined discharge ratio for a first period of time to create a conditioned de-icing material reserve in the bottom of the mixing bowl, g. controlling said water supply, metering unit and de-icing conditioner after step f to continuously produce liquid de-icer at said pre-determined discharge ratio of conditioned de-icing material and water.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0021] FIG. 1 is a perspective view of the brine producing system of the present invention;

[0022] FIG. 2 is a cutaway view perspective view of the brine producing system of the subject invention;

[0023] FIG. 3 is a perspective view of from the rear of the brine producing system of the present invention;

[0024] FIG. 4, is a perspective view of a metering system of the present invention;

[0025] FIG. 5 is a perspective view of the still further alternative metering system of the present invention; and

[0026] FIG. 6 is a perspective view of a salt conditioner.

DESCRIPTION OF THE ENABLING EMBODIMENT

[0027] The material mixing system of the present invention is shown generally at 10. The material mixing system 10 is particularly useful in the production of brine. The brine solution of salt and water and may include additives to improve the overall performance of the solution for controlling ice. Typically, the bulk rock salt is initially solid pieces which are processed to very small pieces and then mixed with water, and if desired additives, to create the brine solution. However, the invention is not limited to the manufacture of a brine solution, for example, the solution could be an ice control chemical such as magnesium chloride or calcium chloride as well as a combination of these with salt to produce a liquid solution for controlling ice. The invention is also not limited to ice control, as it can also be used to mix for example fertilizers. The liquid solution could be a fertilizer solution with the dry fertilizer processed for addition to the water. Any number of fertilizers could be used including but not limited to organic fertilizers, inorganic fertilizers, potash, etc. The invention could also be used with dry weed control substances that have to be processed and added to water, etc.

[0028] For ease of explanation, the invention will be described with respect to producing salt brine. However, as those of ordinary skill will understand, and as described above, other uses are clearly contemplated for the present invention.

[0029] The material hopper 12 receives the bulk rock salt or other material. As will be appreciated by those of ordinary skill in the art, the rock salt is typically not uniform in composition, shape, or size. The composition may be harder or softer salt depending upon its origin and there may be sand pebbles, rocks or other debris in the mix. The shape and size can be anywhere from very fine to very large chunks in a single batch. Because of the inconsistency in the make up of the rock salt, further processing is required to improve the ease of mixing the salt with water in the mixing bowl 18 and to facilitate cleanup.

[0030] The hopper 12 as illustrated has an opening 22 for the receipt of the rock salt and an exit 24 for delivery of the rock salt to a metering unit 14 and then to a material conditioner or processor 16. The metering unit 14 is positioned adjacent the exit 24 to meter rock salt to the material conditioner or processor 16. A programmable control unit 15, see FIG. 3, controls the metering unit 14 to deliver the correct amount of salt to the processor 16. The programmable control unit 15 receives information from a sensor 17. The sensor 17 senses the salinity of the mixture and relays that information back to the unit 15 to control the delivery of material to the conditioner 16. In the disclosed embodiment, the sensor is a toroid conductivity cell or transmitter, but could also be any typical conductivity sensor including a refractory sensor, specific gravity sensor, galvometric sensor, electric conductivity sensor, etc.

[0031] With reference to FIG. 2, a vibrator assembly 26 is positioned in the hopper 12 adjacent to the exit 24 to facilitate the constant flow of rock salt to the metering unit 14. The vibrator assembly 26 includes a vibrator motor 28, which can be either 110V or 120V, connected to a vibrator plate 30. In the preferred embodiment, the plate 30 extends across the exit 24 of the hopper 12. In the disclosed embodiment, the plate is flat. The width of the plate is less than the width of the hopper walls 27 adjacent the exit 24. In this way, when the plate is vibrated, the salt directly adjacent the plate is vibrated and moves to and drops though the gaps between the hopper walls 27 and the plate 30 and is delivered to the metering unit 14. The plate holds the weight of the material off the metering unit and prevents cavitation of the material. As a result, there is a free flow of material to the metering unit 14.

[0032] The vibrator plate 30 can take other shapes, such as for example, a v-shaped plate that presents a knife-like edge in the direction of the opening 22. When the vibrator is operational, the knife-like edge of the plate 30 vibrates the rock salt to prevent cavitation and facilitate flow to the exit 24. The plate 30 is generally spaced directly above and adjacent the exit 24 with the sides of the plate 30 spaced from the walls 27 of the hopper 12. In this way, the rock salt can flow over the plate 30 and though the gaps between the edges of the plate 30 and the walls 27 of the hopper 12 to the exit 24. It should be appreciated that other shaped plates 30 could also be used, for example a curved plate could be used.

[0033] To further facilitate the continuous flow of material to the metering unit 14, the hopper 12 has sloped inner walls 27 to direct the salt within the hopper 12 to the exit 24. It has been found that the sloped inner walls 27 facilitate the delivery of the salt to the exit 24. It should be appreciated by those of ordinary skill in the art, that the amount of slope is a matter of design choice and other angles and slopes could be used.

[0034] It should also be appreciated by those of ordinary skill in the art, that the vibrator and sloped walls might not be needed in some hopper designs. For example, the hopper could be cylindrical and not require the sloped walls; or, the hopper could utilize a conveyor to convey the salt to the metering device and not require the vibrator or sloped walls, etc.

[0035] The metering unit 14 is illustrated in FIG. 2 and includes a beater bar 32 having a plurality of fingers 34 located at or near the bottom 36 of the hopper 12 that extend across the bottom 36 for moving material to the exit 24. As shown in FIG. 2, there are three sets of paddles 34 radially disposed on the outside of the beater bar 32. It should be appreciated by those of ordinary skill the art, that one of more sets of fingers 34 could be used. As the beater bar 32 rotates, the fingers 34 pick-up material in the bottom 36 and supply that material to the exit 24.

[0036] An alternative embodiment of the metering device is shown in FIG. 4. The alternative embodiment has an auger, (not shown) mounted within a tube 42 with an opening 44 in one end of the tube 42 and a discharge 46 in the opposite end of the tube. In this embodiment, the discharge 46 would discharge into the conditioner 16. The metering device of this embodiment operates by moving material with the auger from the opening 44 to the discharge 46. Material is supplied to the opening 44 from the hopper 12 and then augured to the discharge 46. Since the augur is housed in the tube 42, if the speed of the augur is reduced, the amount of material discharged from the discharge 46 will be reduced. Additionally, if the auger is stopped, all flow is stopped immediately because the material in the augur cannot get past the blades of the augur.

[0037] Another alternative embodiment is shown in FIG. 5. The alternative embodiment is a simple gate valve 60 shown schematically. In this embodiment, a chute 62 connects the exit 24 with the conditioner 16. A gate 64 is positioned adjacent the exit 24 to control the discharge of material from the chute 62 to the conditioner 16. The chute 62 can be a half moon shaped chute, or more preferably, a closed chute with the chute being opened and closed by the gate 64. The gate is connected to a solenoid and motor (not shown) and controlling the control unit 15.

[0038] With reference to FIG. 6, the material conditioner 16 is disclosed as a hammer mill 50. The hammer mill 50 has an outer housing or drum 52 with a horizontal rotating shaft 54 on which hammers 56 are mounted. With reference to FIG. 2, a motor 53 (which can be either 110V or 220V) drives the hammer mill 50. The hammers 56 are free to swing on the shaft 54. As the shaft 54 is spun at a high speed inside the housing, material is fed into housing 52 and impacted by the hammers 56. The hammers 56 crush the material which is then expelled through a screen 58 of a selected size. The inlet of the hammer mill 16 is shown at 59.

[0039] Other alternative embodiments of the conditioner 16 could be used, for example, of a rotary concave could be used to condition the material. Rotary concaves are well known to those of ordinary skill in the art and would be used in place of the hammer mill described above.

[0040] The mixing bowl 18 receives the conditioned rock salt from the conditioner 16. The mixing bowl 18 has an upper portion 60 with a circular cross section and a conical base section 62. Water inlet nozzles 64 are positioned in the conical base section 62. In the preferred embodiment, the nozzles 64 are angled with respect to each other to create a circular pattern as the water fills the mixing bowl. Due to the metering of the salt as the water enters the mixing bowl 18, the mixing bowl of the present invention can be easily filled with a standard water hose. This is in contrast to all known brine making systems that require a water pump and large water pipes, 2 to 2 inch pipes to fill the mixing tank.

[0041] Circulating tubing 66 is positioned near the conical base section 62 to circulate the water and further mix the conditioned salt as it is added to the water as the water is added to the mixing bowl 18. Nozzles 68 are placed around the interior of the mixing bowl 18 to circulate the water and salt and if desired, additives. A pump 70 is used to circulate the water and salt mixture. The pump draws water from the inlet 72 and then pumps it into the tubing 66 and out the nozzles 68 to circulate the water and mix the water and salt mixture.

[0042] The mixing bowl 18 includes a drainpipe 74 to drain the mixing bowl 18 for cleaning purposes. Due to the processing of the rock salt prior to its introduction into the mixing bowl 18, there is a relatively small amount of debris left in the bowl 18 when compared to traditional brine making systems. Additionally, the conditioning of the rock salt also processes the debris contained in the salt, reducing large debris pieces into smaller pebbles that are easy to wash from the mixing bowl when the mixing bowl is cleaned. This process will be discussed in greater detail below.

[0043] In the disclosed embodiment, a storage tank 80 is mounted adjacent the mixing bowl 18 to store the brine once it is produced. A supply pipe 82 extends from the mixing bowl 18 to the storage tank 80. The storage tank has a discharge valve 84 for pumping the brine from the tank 80 to the vehicle tanks or other storage tanks. As will be appreciated by those of ordinary skill in the art, the storage tank 80 could take many forms, including bulk storage tanks, in-ground storage tanks, or even a direct pipe connection to other storage tanks, etc. In the disclosed embodiment, the storage tank 80 is generally L-shaped, having a head portion 90 and a base 92. As disclosed, the base 92 supports the mixing bowl 18. In the disclosed embodiment, the mixing bowl 18 and base 92 are separate individual parts, but could be a single unitary part.

[0044] In use, the material mixing system 10 is started by initiating the start function of the programmable control unit 15. If the mixing bowl is empty, due either to it being the initial startup or a startup after the cleaning cycle, the metering device 14 and processor 16 are started, and water is introduced into the mixing bowl 18. At startup, the percent of salt being introduced to the mixing bowl 18 is greater than what is required to make brine. The addition of a greater amount of salt is continued for a period of time to create a salt reserve on the bottom of the mixing bowl 18. When the water level reaches inlet 72, the circulating pump 70 is started by the control unit 15 and circulates the water and salt. As the mixture circulates, the sensor 17 continuously reads and sends the salinity measurement to the control unit 15 which then controls the amount of water and salt being introduced to the mixing bowl to create the desired ratio of salt to water. It is important to note that due to the greater percentage of salt at the initial filling of the mixing bowl 18, a salt reserve is created on the bottom of the mixing bowl 18. This salt reserve dissolves or is replenished continually as needed to aid in keeping the salinity of the brine mixture at the desired ratio. Once the desired ratio is achieved, the brine can then be continually produced or batch produced.

[0045] The invention also has a clean up mode. The clean up mode is initiated by initiating the cleanup function on the control unit 15. Once cleanup is initiated, the metering device 14 and conditioner are stopped. The circulation pump 70 is started and circulates the brine mixture within the mixing bowl 18. Due to the salt reserve dissolving in the bottom of the mixing bowl 18 due to the circulating brine mixture, the salinity will increase. When the salinity increases the control unit 15 signals for the addition of more water. As water is added, the salinity will lower, resulting in the control unit signaling the water to stop. In the disclosed embodiment, circulating pump continues to run for approximately 30 minutes after the salinity has lowered. As the brine circulates, the salt reserve dissolves and the salinity increases. This process is repeated until the salinity does not increase, after which the control unit stops the circulating pump 70.

[0046] Once the circulating pump has stopped, the drainpipe 74 is opened and the mixing bowl 18 is drained. Due to the repeated water circulation and water addition steps, there is very little if any salt remaining in the mixing bowl making cleanup easy as well as using all the available conditioned salt, which is more economical. The material left in the mixing bowl 18 is mainly debris, which due to the conditioning step are small pebbles. Water can be circulated or a hose can be used to wash the debris out of the mixing bowl 18 through the drainpipe 74. The pebbles are easily washed from the mixing bowl due to their size and shape from the conditioning step.

[0047] Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, Obviously, many modifications and variations of the present invention are possible in light of the above teachings and may be practiced otherwise than as specifically described while within the scope of the appended claims. These antecedent recitations should be interpreted to cover any combination in which the inventive novelty exercises its utility. The use of the word said in the apparatus claims refers to an antecedent that is a positive recitation meant to be included in the coverage of the claims whereas the word the precedes a word not meant to be included in the coverage of the claims. In addition, the reference numerals in the claims are merely for convenience and are not to be read in any way as limiting.