WO2011057284A2

WO2011057284A2 - Chemical dispensing system and method

Info

Publication number: WO2011057284A2
Application number: PCT/US2010/056061
Authority: WO
Inventors: Jay W. Hutchison; James M. Scolaro; Carl J. Zaiser; Cedric Chan; Jack D. Kellythorne; John Krahn; Dennis Weeks
Original assignee: Diversey, Inc.
Priority date: 2009-11-09
Filing date: 2010-11-09
Publication date: 2011-05-12
Also published as: WO2011057284A3

Abstract

A chemical dispensing system for a wastewater tank is provided, and in some embodiments including a housing, a battery within the housing, a pump within the housing, and a control system for controlling the pump powered by the battery. The dispensing system can also include a fluid chemical source, a supply line connecting the fluid chemical source and the pump, a nozzle or other dispensing outlet, a dispensing line connecting the pump and the nozzle, and a valve selectively providing fluid flow through the supply line and the dispensing line.

Description

CHEMICAL DISPENSING SYSTEM AND METHOD

BACKGROUND

[0001] Typical lift stations comprise tanks made of concrete and located at least partially below ground. The tanks are often sufficiently large for one or more individuals to enter for inspection, repairs, and other work. One or more pipes or other conduits typically connect the interior of the tank with one or more remote locations, such as stormwater basins, sewerage systems, and the like. A pump, which may be submerged in the tank, pumps wastewater from the tank upwardly to the remote location(s).

[0002] In the tank, grease, oil, and other contaminates of a lower density than water rise to the top of the water in the tank, forming a mat layer (often called a "grease mat layer"). The amount of grease and other matter in the layer tends to build up over time, particularly because the inlet to the pump is often at the bottom of the tank, away from the grease mat layer. As a result, difficulties are often encountered in evacuating the tank and in keeping the pump and conduits clear from clogs. Therefore, the entire contents of the tank (i.e., the grease mat layer, other contaminates, and all the wastewater) are typically periodically evacuated to fully empty the tank - a process that consumes significant time and resources.

SUMMARY

[0003] Some embodiments of the present invention provide a chemical dispensing system for cleaning a wastewater tank of a lift station and/or in treating matter within the tank (e.g., a grease mat layer, fluid within the tank, contaminate buildup on walls of the tank, and the like). In some embodiments, the dispensing system includes a housing, a battery, a pump, and a control system for controlling the pump, wherein at least the pump (and in some embodiments, the battery) is located within and is enclosed by housing. The dispensing system can also include a fluid source, a supply line connecting the fluid source and the pump, a nozzle or other dispensing outlet, a dispensing line connecting the pump and the nozzle, and one or more valves selectively providing flow through the supply line and the dispensing line.

[0004] In some embodiments, a chemical dispenser for a lift station is provided, and comprises a housing; a battery enclosed within the housing; a pump enclosed within the housing, electrically coupled to the battery, and operable to draw fluid from a chemical reservoir; a first valve having opened and closed positions to selectively permit entry of fluid into the housing from a reservoir located outside of the housing; a second valve having opened and closed positions to selectively permit discharge of fluid from the housing by the pump; and a controller coupled to the battery, the pump, and the first and second valves, the controller operable to selectively open the first and second valves so that fluid flows into and out of the housing while both the first and second valves are opened, and to selectively close the first and second valves so that the housing is substantially fluid-tight.

[0005] Other aspects of the present invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 is a schematic representation of a lift station chemical dispensing unit according to an embodiment of the present invention.

[0007] Fig. 2 is a schematic representation of a lift station chemical dispensing unit according to another embodiment of the present invention.

[0008] Fig. 3 is a front view of a lift station chemical dispensing unit embodying the invention.

[0009] Fig. 4 is a right side view of the lift station chemical dispensing unit of Fig. 3.

[0010] Fig. 5 is a back view of the lift station chemical dispensing unit of Fig. 3.

[0011] Fig. 6 is a front view of the lift station chemical dispensing unit of Fig. 3 including a filling tube.

DETAILED DESCRIPTION

[0012] Before any embodiments of the present invention are explained in detail, it is to be understood that the present invention is not limited in its application to the details of construction and the arrangement of components set forth hi the following description or illustrated in the accompanying drawings. The present invention is capable of other embodiments and of being practiced or of being carried out in various ways. [0013] Fig.1 illustrates a lift station chemical dispenser 10, such as for a wastewater treatment and collection system or any other fluid system in which a lift station can be employed. The illustrated lift station chemical dispenser 10 includes a housing 14, a power source in the form of a battery 18, a pump 22, and a control system 26. In some

embodiments, the illustrated housing 14 is an explosion-resistant enclosure, and is constructed of non-flammable cast ferrous metal. In other constructions, the outer housing 14 is constructed of concrete, other metal (e.g., aluminum, steel, titanium, and the like), a high- impact plastic, urethane, or other synthetic material, and the like. Still other outer housing materials are possible (e.g., fiberglass, ceramic materials, and the like), and fall within the spirit and scope of the present invention, although in many applications material that is capable of withstanding shock or impact without appreciable deformation or cracking is preferable.

[0014] In some embodiments, the housing 14 can be strengthened or otherwise reinforced against deformation, cracking, and other damage (such as by shock or impact generated from an explosion or other event) by one or more layers of additional material. By way of example only, the housing 14 illustrated in Fig. 1 is provided with a reinforcing layer of material 30 lining the inside of the housing 14. Alternatively, and depending at least in part upon the material used to construct the housing 14, this reinforcing layer can also or instead be located within the material of the housing 14 and/or on the exterior of the housing 14. The reinforcing layer of material 30 in the illustrated embodiment is an engineered material, such as a fiber weave material (e.g., a type of which is manufactured under the trade name

Kevlar® by E.I. du Pont de Nemours and Company), a polymeric foam layer (e.g., a type of which is manufactured under the trade name SpetraShield by CCI Spectrum, Inc.), a graphite fiber material, and the like, although other types of reinforcing layers can instead be used, such as a metal grid, mesh, or foil layer, a reinforced or non-reinforced fiberglass layer, and the like.

[0015] The housing 14 and any reinforcing layers 30 can have any shape and size capable of performing the housing functions described herein, and can include any number of layers of the same or different material. In some embodiments, the housing 14 is constructed to meet the requirements of the National Fire Protection Association (NFPA) 820 "Standard for Fire Protection in Wastewater Treatment and Collection Facilities" guide for fire protection in wastewater treatment and collection facilities. Specifically, in such embodiments, the outer housing 14 meets Class I, Division I, Group C&D requirements such that the lift station chemical dispenser 10 is qualified to operate in areas that require explosion proof equipment.

[0016] With continued reference to the illustrated embodiment of Fig. 1, two apertures are defined in the housing 14. The first aperture is a fluid supply aperture 34, and includes a fastening portion 38 and a line portion 42, The illustrated fastening portion 38 is threaded, such as by including National Pipe Threads (NPT) tapped therein, whereas the line portion 42 includes a fitting suitable for retaining a pipe, hose, or other conduit fitting, such as a compression tube fitting. The second aperture is a dispensing aperture 46, and also includes a fastening portion 50 and a line portion 54. The illustrated fastening portion 50 is threaded, such as by including National Pipe Threads (NPT) tapped therein, whereas the line portion 54 includes a fitting suitable for retaining a pipe, hose, or other conduit fitting, such as a compression tube fitting. In other embodiments, the fastening portions 38, 50 and the line portions 42, 54 can be different (e.g., having no threads, having metric threads or threads adapted to any other standard, having welding, soldered, glued, or brazed joints, having swaged, interference fit, or any other type of pipe, hose, or other conduit fitting, as desired).

[0017] The battery 18 of the illustrated embodiment is located within the housing 14, and provides electrical power to the lift station chemical dispenser 10. The illustrated battery 18 is a sealed type battery that provides six volt direct current electrical power. In other embodiments, the battery 18 can be of a different type (e.g., lithium ion, lead-acid, etc.) or a different voltage/current, as desired, and can be re -chargeable in some cases. As an alternative to the use of a battery to power the lift station chemical dispenser 10, the lift station can be supplied with power via a power line running to the housing 14 and extending into the housing 14. In such cases, the power line can extend through an aperture extending through a wall of the housing 14 in a fluid or air-tight manner, such as by one or more gaskets, seals, or gasket or sealing material, or by an electrical connector fitted within the aperture in a fluid or air-tight manner.

[0018] The pump 22 of the illustrated embodiment is a peristaltic pump 22, and is located within the housing 14. The pump 22 includes a motor (not shown), an inlet 58, a

compression zone (not shown), and an outlet 62. The illustrated motor is an electric motor, and is connected to the battery 18 for receiving power from the battery 18. The compression zone is positioned between the inlet 58 and the outlet 62, and operates to move fluid from the inlet 58 to the outlet 62. In some embodiments, the compression zone includes a resilient tube and one or more compression rollers, cams, or other elements that move along the resilient tube to define one or more chambers within the tube. The chambers (with fluid therein) move with the rollers in the direction of the outlet 62, whereby movement of the chambers carries fluid from the inlet 58 to the outlet 62 of the pump 22 to generate fluid flow. In other embodiments, a different pump can be used, such as a centrifugal pump, a piston pump, a diaphragm pump, and the like.

[0019] The control system 26 of the illustrated embodiment is located within the housing 14, and includes a supply solenoid valve 66, a dispensing solenoid valve 70, and a controller 74. The supply solenoid valve 66 is in fluid communication with and between the supply aperture 34 and the inlet 58 of the pump 22, and in the illustrated embodiment is coupled to the supply aperture 34 via a threaded nipple 78. The threaded nipple 78 threads into the fastening portion 38 of the supply aperture 34 and into the supply solenoid valve 66. In other embodiments, the supply solenoid valve can be fluidly coupled to the supply aperture 34 in any other suitable manner using any other fluid fitting(s) and conduit(s) desired. With continued reference to Fig. 1 , a conduit 82 is connected between the supply solenoid valve 66 and the pump inlet 58 to establish fluid communication therebetween. The illustrated supply solenoid valve 66 is a normally closed two -position two-way valve with a spring return and an electrically actuated solenoid, and is shown in the closed position such that fluid flow between the supply aperture 34 and the pump 22 is inhibited. When the illustrated supply solenoid valve 66 is energized by the battery 18, the valve 66 moves to the supply position (shown in the left hand block) to permit fluid to flow from the supply aperture 34 to the pump inlet 58.

[0020] The dispensing solenoid valve 70 is located between the dispensing aperture 46 and the outlet 62 of the pump 22, and in the illustrated embodiment is coupled to the dispensing aperture 46 via a threaded nipple 86. The threaded nipple 86 threads into the fastening portion 50 of the dispensing aperture 46 and into the dispensing solenoid valve 70. In other embodiments, the dispensing solenoid valve 70 can be fluidly coupled to the dispensing aperture 46 in any other suitable manner using any other fluid fitting(s) and conduit(s) desired. With continued reference to Fig. 1, a conduit 90 is connected between the dispensing solenoid valve 70 and the pump outlet 62 to establish fluid communication therebetween. The illustrated dispensing solenoid valve 70 is a normally closed two-position two-way valve with a spring return and an electrically actuated solenoid, and is shown in the closed position such that fluid flow between the dispensing aperture 46 and the pump 22 is inhibited. When the dispensing solenoid valve 70 is energized by the battery 18, the valve 66 moves to the supply position (shown in the left hand block) to permit fluid to flow from the pump 22 to the dispensing aperture 46.

[0021] Although solenoid-actuated spring-biased valves are used for the supply and dispensing valves 66, 70 in the illustrated embodiment of Fig. 1, it should be noted that other types of valves can instead be used. By way of example only, the solenoid-operated valves 66, 70 can be replaced by valves operated by motors (e.g., servo motors), pneumatic or hydraulic actuators, and the like, and can take the form of ball valves, butterfly valves, spool valves, and the like.

[0022] The controller 74 of the illustrated embodiment is a microprocessor-based controller with circuitry suitable for receiving power from the battery 18 to which it is connected, for controlling actuation of the valves 66, 70 (to which the controller 74 is connected), and for controlling operation of the motor of the pump 22 (to which the controller 74 is also connected). In alternative embodiments, any other type of controller 74 can be used, such as an assembly of discrete logic elements by way of example only. The controller 74 can be located within the housing 14 as shown in Fig. 1. In alternative embodiments, the controller 74 can be located remotely from the housing 14 while still being connected thereto for wired control of the pump motor and valves 66, 70 (in which case the controller 74 can be connected to the pump motor and valves 66, 70 via one or more communication lines extending through one or more apertures in a wall of the housing 14 or in communication therethrough via one or more electrical connectors in the wall), or for wireless control of the pump motor and valves 66, 70.

[0023] With continued reference to Fig. 1, the controller 74 controls the position of the supply solenoid valve 66 and the dispensing solenoid valve 70, and also operates the motor to selectively drive the pump 22. In some embodiments, the controller 74 operates on a timer such that the supply solenoid valve 66, the dispensing solenoid valve 70, and the pump 22 are operated at predetermined times and on a periodic basis, thereby dispensing fluid at such times. In other times, the controller 74 operates in other manners to operate the valves 66, 70 and the pump 22, such as upon detection of a low or high threshold chemical level witMn tank of the lifting station being reached and communicated to the controller, a continual slow operation of the pump 22 with the valves 66, 70 partially or fully open, and the like. In any of these manners, the controller 74 can cause the valves to open 66, 70 and the pump 22 to operate for dispensing a fluid into the tank of the lifting station to clean the tank and/or to treat fluid therein.

[0024] The pump 22 illustrated in Fig. 1 can be operable by the controller 74 in on and off states while the valves 66, 70 are open as described below. In some embodiments, the pump 22 can be operated at different speeds by the controller 74 as desired, and/or can be operated for different lengths of time depending at least in part upon varying rates and amounts of fluid dispense desired. Alternatively, the controller 74 can operate the pump 22 simply at regular intervals for a fixed length of time and/or rate of fluid dispense.

[0025] . In some embodiments, any or all of the connections between the controller 74 and the pump motor and valves 66, 70 can be wireless connections enabled by a wireless transmitter coupled to the controller 74 for sending signals from the controller 74 to the pump motor, supply valve 66, and/or dispensing valve 70, and a wireless receiver coupled to the pump motor, supply valve 66, and/or dispensing valve 70 for receiving such signals.

[0026] As shown in Fig. 1, a fluid tank 94 holds a quantity of fluid (e.g., cleaning chemicals, fluid treatment chemicals, and the like), and can be coupled to and supply fluid to the pump 22 for dispense by the chemical dispenser 10. In some embodiments, the fluid tank 94 is located remotely from the housing 14. In other embodiments, the fluid tank 94 is supported by a bracket that also supports the housing 14 (see Figs. 3-6). In the illustrated embodiment, the fluid is concentrated ReNew brand degreaser and odor control chemicals, although any other type of cleaner or fluid treatment chemical can be used for dispense into the lift station. A supply line 98 can be provided between the cleaner tank 94 and the supply aperture 34. The illustrated supply line 98 couples to the supply aperture 34 via the compression tube fitting, although any other suitable conduit connection fitting can be used as desired.

[0027] As also shown in Fig. 1, a nozzle 102 is coupled to the pump 22, and receives fluid from the pump 22 upon operation thereof. A dispensing line 106 is provided between the dispensing aperture 46 and the nozzle 102. The illustrated dispensing line 106 couples to the dispensing aperture 46 via the compression tube fitting, although any other suitable conduit connection fitting can be used as desired. In some embodiments, the nozzle 102 is located remotely from the housing 14, such as in a position suitable for spraying or otherwise dispensing fluid at one or more desired locations within the lift station (e.g., sprayed upon one or more walls of a tank within the lift station, dispensed within a conduit in fluid communication with a tank of the lift station, dispensed directly into the fluid within the tank of the lift station, sprayed upon a grease mat or other contaminant floating at the surface of fluid withm the tank, and the like). Any number of nozzles 102 can be coupled to the pump 22 for dispense of fluid in any of these locations. Also, and as an alternative to nozzles 102, other types of fluid dispensing outlets can be used, such as an outlet port at the end of the dispensing line 106, a distribution manifold with one or more openings therein, the end of a tube, hose, or pipe defining the dispensing line 106, and the like.

[0028] In operation, a lift station (not shown) that can have a fluid holding tank (also not shown) is arranged to pump fluid to or from another location. By way of example only, as grease and other contaminants build up in the fluid within the tank, it is necessary to clean the wastewater tank (which can include emptylng the tank), and/or to treat the fluid within the tank. To aid in this cleaning operation, the lift station chemical dispenser 10 can be provided within the tank.

[0029] The illustrated chemical tank 94 is located outside the wastewater holding tank such that the cleaner tank 94 can be refilled periodically with degreaser, odor fighting agents, or other chemicals without accessing the holding tank. In the illustrated embodiment, the housing 14 and the nozzle 102 are positioned within the wastewater holding tank.

[0030] When the controller 74 operates the lift station chemical dispenser 10 in the illustrated embodiment, the supply solenoid valve 66 and the dispensing solenoid valve 70 are actuated such that chemicals are provided from the chemical tank 94 to the pump inlet 58, the pump 22 is operated to move the chemicals from the inlet 58 to the outlet 62, and the dispensing solenoid valve 70 is actuated such that the chemicals are provided from the pump 22 outlet to the nozzle 102. The chemicals are then sprayed into the wastewater holding tank to dissolve grease and other contaminants therein, thereby cleaning the holding tank. In some embodiments, the chemicals are sprayed onto the walls at high pressure to break up layers of grease or other contaminants that may have formed thereon.

[0031] In some embodiments, the lift station chemical dispenser 10 operates only when the tank of the lift station is empty and during a wash-down operation for cleaning the inside of the tank. In other embodiments, the lift station chemical dispenser 10 operates to periodically dose the wastewater within the wastewater holding tank to inhibit contaminant build-up and/or to periodically clean the tank or other parts of the lift station. In other embodiments, the lift station chemical dispenser 10 can be used differently to suit particular needs and applications, as desired.

[0032] The lift station chemical dispenser 10 illustrated in Fig. 1 is adapted for

environments in which the dispenser can be subject to shock or impact. Also, in some environments, it may be necessary or desirable to the dispenser to be fluidly or hermetically sealed from the outside environments, such as in environments where sparks or other ignition-causing events can trigger combustion of gasses in the environment of the dispenser 10. By way of example only, the dispenser 10 can be used in wastewater tanks for lifting stations, which in some cases can experience significant buildup of methane or other flammable gasses.

[0033] Accordingly, the sealed nature of the housing 14, with limited apertures

therethrough to the above-described internal components of the dispenser, reduces the opportunity for sparks or other electrical disturbances and/or heat (e.g., from the pump or pump motor) to serve as ignition sources. To this end, the fluid supply and dispensing — apertures 34, 46 through the housing 14 are fluidly sealed in some embodiments, and can also be hermetically sealed as needed. Any other apertures through wall(s) of the housing 14 can be similarly sealed.

[0034] Fig. 2 illustrates another embodiment of a lift station chemical dispenser

according to the present invention. This embodiment employs much of the same structure and has many of the same features as the embodiments of the lift station chemical dispenser described above in connection with Fig. 1. Accordingly, the following description focuses primarily upon the structure and features that are different than the embodiments described above in connection with Fig. 1. Reference should be made to the description above in connection with Fig. 1 for additional information regarding the structure and features, and possible alternatives to the structure and features of the lift station chemical dispenser illustrated in Fig. 1 and described below.

[0035] The lift station chemical dispenser 110 illustrated in Fig. 2 is similar to the lift station chemical dispenser 10 of Fig. 1 except that the supply solenoid valve 66 and the dispensing solenoid valve 70 have been replaced by a control solenoid 114 that is a normally closed two- position four- way valve. A spring return and electrically actuated solenoid can operate similarly to the supply solenoid valve 66 and dispensing solenoid valve 70 of Fig. 1. In other embodiments, a different control system 26 can be used to provide selective fluid flow and power to the pump 22 such that the lift station chemical dispenser 10 is controlled as desired.

[0036] In some alternative embodiments, the lift station chemical dispenser 10, 110 is arranged with the chemical tank 94 and the nozzle 102 coupled to the outer housing 14 such that the lift station chemical dispenser 10, 110 is a single integral unit. In such embodiments, the lift station chemical dispenser 10, 110 can be lowered or otherwise installed within an area to be dosed (i.e., cleaned or treated) with chemical (e.g., a lift station or tank of a lift station). A removable filling tube can be used in such embodiments such that the chemical tank 94 can be filled from outside the lift station with the lift station chemical dispenser 10, 110 in place. When one or more cleaning or treating operations are completed, the lift station chemical dispenser 10, 110 can be removed as a single integral unit from the lift station.

[0037] Figs. 3-6 show a lift station chemical dispensing unit 10 according to one embodiment of the invention. The illustrated unit includes the arrangement shown in Fig. 1 , wherein like numerals are used to indicate like components. As shown in Figs. 3-6, the housing 14 and the chemical tank 94 are supported by a bracket 118. The supply line 98 delivers chemicals from the chemical tank 94 to the housing 14 through the line portion 42 of the supply aperture 34. Chemicals are pumped to the nozzle 102 through the line portion 54 of the dispensing aperture 46 and the dispensing line 106. Also, Fig. 6 shows a refilling line 122 that may be used to add additional chemical to the chemical tank 94.

[0038] The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention. For example, although the valves 66, 70 illustrated in Figs. 1 and 2 are solenoid-operated valves as described above, in some embodiments, either or both valves 66, 70 can be replaced by one-way valves (e.g., ball check valves, reed valves, and the like) permitting fluid flow into and out of the pump 22 upon operation of the pump 22, while still keeping the housing 14 fluid-tight or hermetically sealed when the pump 22 is not in operation.

Claims

CLAIMS What is claimed is:

1. A chemical dispenser for a lift station, the chemical dispenser comprising: a housing;

a battery enclosed within the housing;

a pump enclosed within the housing, electrically coupled to the battery, and operable to draw fluid from a chemical reservoir;

a dispensing outlet hi fluid communication with the pump and through which fluid from the pump is dispensed to the lift station in operation of the pump; and a controller coupled to the battery and the pump, and operable to selectively allow fluid flow to the pump and from the pump to the dispensing outlet.

2. The chemical dispenser of claim 1, further comprising at least one valve coupled to the controller and operable by the controller to open and close fluid flow to the pump from a chemical reservoir.

3. The chemical dispenser of claim 2, wherein the at least one valve includes a spool valve.

4. The chemical dispenser of claim 1, further comprising at least one valve coupled to the controller and operable by the controller to open and close fluid flow from the pump to the dispensing outlet.

5. The chemical dispenser of claim 4, wherein the at least one valve includes a spool valve.

6. The chemical dispenser of claim 1, further comprising a valve in

communication with a pump inlet and a pump outlet for selectively controlling fluid flow through the pump.

7. The chemical dispenser of claim 6, wherein the valve is solenoid operated and is controlled by the controller.

8. The chemical dispenser of claim 1, wherein the battery and pump are sealed within an interior of the housing, and are selectively open to an exterior of the housing only via a first fluid line through which fluid enters the housing to the pump, and via a second fluid line through which fluid exits the housing from the pump.

9. The chemical dispenser of claim 8, wherein the battery and pump are hermetically sealed within the interior of the housing.

10. The chemical dispenser of claim 1 , wherein the controller is located within the housing.

11. The chemical dispensing of claim 1, wherein the housing meets the requirements of Class I. Division I, Group C&D of the National Fire Protection Association (NFPA) 820 "Standard for Fire Protection in Wastewater Treatment and Collection

Facilities" guide for fire protection in wastewater treatment and collection facilities.

12. The chemical dispenser of claim 1, further comprising a chemical tank located outside of the housing and at least partially defining the chemical reservoir.

13. The chemical dispenser of claim 12, wherein the chemical tank is coupled to the housing via a bracket.

14. The chemical dispenser of claim 1, wherein the housing includes a reinforcing layer in at least one of a position lining an internal surface of the housing, covering an external surface of the housing, and located within material of the housing.

15. A chemical dispenser for a lift station, the chemical dispenser comprising: a housing;

a battery enclosed within the housing;

a first valve having opened and closed positions to selectively permit entry of fluid into the housing from a reservoir located outside of the housing;

a second valve having opened and closed positions to selectively permit discharge of fluid from the housing by the pump; and

a controller coupled to the battery, the pump, and the first and second valves, the controller operable to selectively open the first and second valves so that fluid flows into and out of the housing while both the first and second valves are opened, and to selectively close the first and second valves so that the housing is substantially fluid-tight.

16. The chemical dispenser of claim 15, wherein the housing is hermetically sealed when the first and second valves are closed.

17. The chemical dispenser of claim 15, wherein the first and second valves are part of the same valve.

18. The chemical dispenser of claim 15, further comprising:

a chemical tank located outside of the housing; and

a fluid line supplying fluid from the chemical tank to the first valve.

19. The chemical dispenser of claim 18, wherein the chemical tank is coupled to the housing via a bracket.

20. The chemical dispenser of claim 15, wherein the housing includes a reinforcing layer in at least one of a position lining an internal surface of the housing, covering an external surface of the housing, and located within material of the housing.