WO2020060528A1

WO2020060528A1 - A printing system

Info

Publication number: WO2020060528A1
Application number: PCT/US2018/051317
Authority: WO
Inventors: Ziv SEEMANN; Chen TALMOR; Erez Heldy
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2018-09-17
Filing date: 2018-09-17
Publication date: 2020-03-26

Abstract

In an example, a printing system comprises a printer and a climate control system to operate with the printer. The printing system comprises a flow circuit passing through the printer, out from the printer and into the climate control system, through the climate control system, and out from the climate control system and back into the printer. The climate control system comprises: a contaminant separator located in the flow circuit, the contaminant separator to separate out at least one contaminant from fluid moving in the flow circuit; and a fan located in the flow circuit, the fan to move the fluid from the printer to the contaminant separator, and from the contaminant separator into the printer. The printing system comprises a pressure sensor located, in the flow circuit, upstream of the contaminant separator and downstream of the fan.

Description

A PRINTING SYSTEM

BACKGROUND

[0001] In certain printing operations, the internal environment of commercial and industrial printers can affect the quality of the print output and may be detrimental to some of the printer components. It may be desirable to control the internal environment of the printer. In certain printing operations, the temperature and humidity of the internal environment of the printer may be controlled to improve the quality of the print output.

[0002] It may also be desirable to reduce emissions from the printer of contaminants generated during the printing process. In certain printing operations, the air from the internal environment of the printer may be treated to remove airborne contaminants thereby reducing such undesirable emissions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Various features of the present disclosure will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate features of the present disclosure, and wherein:

[0004] Figure 1 is a block diagram illustrating an example of a climate control system.

[0005] Figure 2 is a schematic diagram illustrating an example of a printing system comprising a printer and a climate control system.

[0006] Figure 3 is a block diagram illustrating an example of a printing system comprising a printer and a climate control system.

[0007] Figure 4 illustrates an example of a climate control system.

[0008] Figure 5 system is a diagram of an example controller that may be incorporated into a climate control system according to this disclosure. DETAILED DESCRIPTION

[0009] Certain printers may operate more effectively if the environmental conditions of an internal space defined by the printer are controlled. Controlling the internal environment of the printer may allow the print quality to be maintained at an acceptable standard. For example, the printing materials used to produce an image on a print target may fix, or set, in an effective manner when the environment around the print target is maintained at a predetermined condition for a period after the image is printed on the print target. For example, it may be desirable to control the humidity and/or the temperature of the environment around the print target as the printing fluid fixes on the print target after the image has been printed.

[0010] Certain printing processes may use printing materials that emanate contaminants into the internal environment of the printer. In certain examples, the printing processes for printing an image may emanate contaminants into the atmosphere around the printing area of the printer. The printing area may be considered the area of a printer where images are produced on a print target. For instance, printed pigments or dyes may emanate contaminants into the atmosphere in the printer as they are deposited on a print target and/or are fixing to the printer target. It may therefore be desirable to control the contaminant level of the internal environment of a printer in which such processes are performed. Controlling the internal environment of the printer, for example such as by controlling the temperature, humidity, and/or contaminant level, may also prolong the lifespan of components of the printer.

[0011] Controlling the contaminants in the internal environment of the printer may be beneficial in reducing emissions of contaminants from the printer since the printer is a machine that may not be a hermetically sealed machine. In certain examples, contaminants can be reduced in the internal environment of the printer by suitably treating at least one fluid from inside the printer thereby reducing emissions of the contaminants into the external environment around the printer. Reducing emissions of the contaminants into the external environment around the printer may be beneficial to persons who may need to be near the printer during operation, for example. Furthermore, the reduction of contaminant emissions may reduce environmental pollution that would otherwise be generated by the printing process.

[0012] Certain printing processes may use printing materials that generate volatile organic compounds (VOCs). The VOCs may be generated as undesirable vapours during certain printing processes. The VOCs may be generated, for example, from the use of certain inks and toners. VOCs generated in certain printing processes may be considered as undesirable contaminants. It may be desirable to reduce VOC contaminants in the internal environment of the printer by suitably treating at least one fluid from inside the printer and, thereby, reduce emissions of the VOC contaminants into the external environment around the printer.

[0013] A ‘printer’, as used in this document, may describe any commercially or industrially available device that can produce a human-readable or -viewable enduring image of graphics or text on a print target. The‘printer’ may be, for example, any digital printing press or printer for industrial or home use. The print target may be any suitable printing medium such as paper or card, for example.

[0014] A ‘fluid’, as used in this document, may describe any flowable substance. In certain examples, the‘fluid’ may be a mixture of gases. The‘fluid’, as used in this document, may comprise a vapour or vapours. A vapour is a substance in its gas phase at a temperature lower than its critical temperature, which means that, for example, the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature. The‘fluid’, as used in this document, may comprise an aerosol. In general, an aerosol is a colloid of fine solid particles or liquid droplets, in a gas. A colloid is a substance in which microscopically dispersed insoluble particles are suspended throughout another substance. For example, the aerosol may include suspended powder particles. The term ‘aerosol’ should be taken as meaning an aerosol, a vapour or a combination of an aerosol and vapour. For reasons of convenience, as used herein, the term‘fluid’ should be taken as meaning at least one of a gas, vapour, or aerosol or as meaning any combination of gas(es), vapour(s), or aerosol(s). [0015] In certain examples, the fluid may comprise air. In certain examples, the fluid may comprise an aerosol as a colloid of fine solid particles or liquid droplets in air. In certain examples, the fluid may comprise a gas mixture of air and at least one vapour. In certain examples, the fluid may comprise an aerosol as a colloid of fine solid particles or liquid droplets in a gas mixture of air and at least one vapour.

[0016] A‘contaminated fluid’, as used in this document, may describe a fluid that contains at least one contaminant. A contaminant may be described an undesirable substance or material. In certain examples, the‘contaminated fluid’ may comprise at least one gaseous contaminant present in the fluid. In certain examples, the ‘contaminated fluid’ may comprise at least one contaminant present in the fluid as a vapour. In certain examples, the‘contaminated fluid’ may comprise at least one contaminant present in the fluid as an aerosol. In certain examples, the‘contaminated fluid’ may comprise more than one contaminant present in the fluid. For example, at least one gaseous contaminant and at least one contaminant as an aerosol may be present in the fluid. The‘contaminated fluid’ may be described as dirty fluid or dirtier fluid. The‘contaminated fluid’ may comprise air. A‘contaminated fluid’, as used in this document, may describe a fluid that has an undesirable temperature and/or an undesirable humidity level.

[0017] A‘treated fluid’, as used in this document, may describe a fluid that has been subjected to a treatment that changes the properties or the condition of the fluid. In certain examples, the treatment may reduce the amount of at least one contaminant in the fluid. In certain examples, the treatment may reduce the amount of more than one contaminant in the fluid. In certain examples, the treatment may substantially remove at least one contaminant from the fluid. The treated fluid may be described as clean fluid, or cleaner fluid. The‘treated fluid’ may comprise air.

[0018] ‘Volatile organic compound(s)’, and ‘VOC(s)’, as used in this document, may describe organic chemicals that have a high vapour pressure at ordinary room temperature. One definition of a VOC is‘any organic compound having an initial boiling point less than or equal to 250 °C’. VOCs may be generated during certain printing processes and considered an undesirable contaminant resulting from the printing process in accordance with the description of a contaminant above.

[0019] A climate control system may be provided to operate with a printer, which may be, for example, the printer defined above. The climate control system may operate to control the internal environment of the printer. The climate control system may operate to control the internal environment of the printing area of the printer. A printing system may comprise the printer and the climate control system. In certain examples, the printing system may include other systems, units or modules that operate together to perform a printing process.

[0020] In certain examples, the printing system may comprise the climate control system as a separate unit and the printer as a separate unit. The control system unit may be attached to the printer unit to be connected to each other so that they can operate together. For example, the printer and the climate control system may be separate units that may be supplied to a user independently or together.

[0021] In certain examples, the printer and the climate control system may be integrated together in one unit to form the printing system as a single unit, which may be referred to as‘a printer’. The printing system unit may include other systems, units or modules that operate together to perform a printing process.

[0022] The climate control system may move fluid from the printer to the climate control system, treat the fluid to reduce the amount of at least one contaminant in the fluid, and move the fluid from the climate control system to the printer. The fluid may contain at least one contaminant. In certain examples, the fluid may be air containing at least one contaminant such as a VOC generated during a printing process, for example

[0023] The printing system may comprise a flow circuit in which the fluid may be moved. The flow circuit may pass through the printer, out from the printer and into the climate control system, pass through the climate control system, out from the climate control system and back into the printer. [0024] The climate control system may comprise a fluid flow inducer and a contaminant separator. When the climate control system is in use in the printing system, the fluid flow inducer and the contaminant separator may be located in the flow circuit.

[0025] When the climate control system is in use in the printing system, the fluid flow inducer may move fluid around the flow circuit of the printing system. The fluid flow inducer may, in use, move fluid from the printer through the flow circuit and to the contaminant separator. The fluid flow inducer may, in use, move fluid from the contaminant separator through the flow circuit and into the printer.

[0026] The contaminant separator may, when the climate control system

100 is in use in the printing system, treat the fluid moving in the flow circuit by separating out at least one contaminant from the fluid.

[0027] An example climate control system 100 is illustrated in the block diagram of Figure 1 . The climate control system 100 may comprise a flow passage 10. The flow passage 10 may form a portion of the flow circuit of the printing system when the climate control system is in use.

[0028] In use, contaminated fluid may be drawn into the flow passage 10 from the printer and treated by the climate control system to separate out one or more contaminants from the contaminated fluid to produce a treated fluid. The treated fluid may be expelled by the climate control system 100 through the flow passage 10 into the printer.

[0029] The flow passage 10 may comprise an inlet 12 and an outlet 14. The inlet 12 may receive the contaminated fluid drawn from the printer. The inlet 12 may be to fluidly communicate with a contaminated fluid outlet of the printer when the climate control system 100 is in use. The treated fluid may be returned to the printer through the outlet 14. The outlet 14 may be to fluidly communicate with a treated air inlet of the printer.

[0030] In certain examples, where the printer and climate control system are separate units, the inlet 12 may comprise coupling features to cooperate with complementary coupling features on the contaminated fluid outlet of the printer. In certain examples, where the printer and climate control system are separate units, the outlet 14 may comprise coupling features to cooperate with complementary coupling features on the printer treated air inlet.

[0031] As described above, the climate control system 100 may comprise the fluid flow inducer 20 and the contaminant separator 22. In certain examples, the fluid flow inducer 20 may be a fan. In some examples, the fluid flow inducer 20 may be a compressor. In certain examples, the fluid flow inducer 20 may be a pneumatic pump. The fluid flow inducer 20 may be located in the flow passage 10. The contaminant separator 22 may be located in the flow passage 10.

[0032] In certain examples, where the fluid flow inducer 20 is a fan, the fan may comprise a centrifugal fan. In certain examples, the fan may comprise a blower. In certain examples, the fan may comprise an axial fan.

[0033] The fluid flow inducer 20 may, in use, draw the contaminated fluid from the printer through the inlet 14 of the flow passage 10 and to the contaminant separator 20.

[0034] The contaminant separator 20 may produce the treated fluid by separating out one or more contaminants from the contaminated fluid delivered through the flow passage 10 to the contaminant separator 20. In certain examples, the contaminant separator 20 may produce the treated fluid by separating one or more VOCs from the contaminated fluid delivered through the flow passage 10. In certain examples, the contaminant separator 20 may produce treated air by separating out one or more VOCs from contaminated air delivered through the flow passage 10.

[0035] The contaminant separator 20 may produce the treated fluid by separating one or more contaminants out from the contaminated fluid to reduce the amount of the one or more contaminants in the treated fluid as far as is practical. In other words, a trace amount of the one or more contaminants may remain in the treated air following treatment by the contaminant separator. [0036] The fluid flow inducer 20 may, in use, draw treated fluid from the contaminant separator 20 and expel the treated fluid into the printer through the outlet 14.

[0037] In certain examples, the climate control system 100 may comprise a controller 24. The controller 24 may, when the climate control system 100 is in use, control the fluid flow inducer 20. The controller 24 may, for example, control an output of the fluid flow inducer 20. In certain examples, the output of the fluid flow inducer 20 may be a power level of the fluid flow inducer 20. For example, the controller 24 may control the power output of the fluid flow inducer 20. In certain examples, the output of the fluid flow inducer 20 may be a pressure rise of a fluid flowing through the fluid flow inducer 20. In certain examples, the output of the fluid flow inducer 20 may be a flow rate of a fluid flowing through the fluid flow inducer 20. For example, the controller 24 may control the pressure rise and/or flow rate of the fluid flowing through the fluid flow inducer 20 by altering the speed of the fluid flow inducer 20.

[0038] The controller 24 may, when the climate control system 100 is in use, control the fluid flow inducer 20 based on a determination of a pressure of the contaminated fluid in the inlet 12 of the flow passage 10. For example, the controller 24 may control the output of the fluid flow inducer 20 based on a determination of a pressure of the contaminated fluid in the inlet 12 of the flow passage 10. In certain examples, the determination of the pressure of the contaminated fluid in the inlet 12 may be derived from a pressure measurement. In certain examples, the determination of the pressure of the contaminated fluid in the inlet 12 may be derived from a calculation based on a measurement of other properties of fluid moving in the flow passage 10. It will be understood that the functions of the controller 24, in certain examples, may be performed by a controller separate from the climate control system 100. For example, the functions of the controller 24 may be performed in a controller of the printer, such as the example controller of the printer described herein, where the controller of the printer may be communicatively connected to the climate control system 100. [0039] In certain examples, the printing system may comprise a pressure sensor. In certain examples, the pressure sensor may be located in the flow circuit, and located upstream of the contaminant separator, and located downstream of the fluid flow inducer. The pressure sensor may produce an output commensurate with the pressure of the fluid at the location of the pressure sensor in the flow circuit.

[0040] In certain examples, where present, the controller 24 of the climate control system 100 may control the output of the fluid flow inducer 20 based on a determination of the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 wherein the determination of the pressure is derived from the output of the pressure sensor. In certain examples, the pressure sensor may be located in, or proximate to, the inlet 12 of the flow passage 10. In other examples, the pressure sensor may be located in the flow circuit some distance from the inlet 12 of the flow passage 10. In such circumstances, the determination of the pressure of the contaminated fluid in the inlet 12 may be derived by utilizing a determined pressure drop across a portion of the flow circuit between the pressure sensor and the inlet 12 of the flow passage 10.

[0041] In certain examples, the climate control system 100 may comprise the pressure sensor, for example, pressure sensor 50 illustrated in Figure 1 .

[0042] In certain examples, the pressure sensor 50 may be located substantially in the inlet 12 of the flow passage 10. In certain examples, the pressure sensor 50 may be located in the flow passage 10 proximate to the inlet 12 of the flow passage 10. The determ ination of the pressure of the contam inated fluid in the inlet 12 of the flow passage 10 may be derived from the output of the pressure sensor 50.

[0043] By controlling the fluid flow inducer 20 based on a determination of a pressure of the contaminated fluid in the inlet 12 of the flow passage 10, the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 can itself be controlled because, in use, the fluid flow inducer 20 moves fluid around the flow circuit. In certain examples, the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 may be controlled to approximately -50 Pa gauge pressure, that is 50 Pa below atmospheric pressure.

[0044] The Applicant has found that by controlling the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 can reduce leaks of contaminants from the internal space of the printer and/or printing area, which, as discussed above, may result in undesirable contaminant emissions from the printer. The Applicant has also found that controlling the pressure of the contaminated fluid in the inlet 12 can reduce build-up of contaminants in the internal space of the printer and/or printing area, which would otherwise present a safety issue.

[0045] To reduce leaks and the build-up of contaminants, it is desirable to maintain the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 at a minimum level of pressure below atmospheric pressure, i.e. a certain level of negative gauge pressure. For example, the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 may be maintained at approximately 50 Pa below atmospheric pressure or lower.

[0046] If the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 is too high, i.e. higher than the minimum level of pressure below atmospheric pressure then the fluid pressure in the printer and/or printing area may also be too high. If the fluid pressure in the printer and/or printing area is too high, then leaks of contaminants may increase and/or a build-up of contaminants may occur inside the printer. For example, where VOCs are generated in a printing process, then if the fluid pressure in the printer and/or printing area is too high then VOC emissions from the printer may increase and/or a build-up of VOCs may occur inside the printer. As certain VOCs present an explosion risk, it is desirable that they do not build up inside a printer.

[0047] The Applicant has found that if the determined pressure of the contaminated fluid in the inlet 12 of the flow passage 10 is too high, the output of the fluid flow inducer 20 may be reduced. Accordingly, if the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 is determined to be above a predetermined pressure, controller may reduce the output of the fluid flow inducer 20 until the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 is determined to be below the predetermined pressure. Reducing the output of the fluid flow inducer 20 may reduce the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 thereby reducing contaminant leaks from the printer and/or reducing build-up of contaminants inside the printer. Emissions of contaminants from the printer may therefore be controlled and the safety risks, such as from explosions or fires, may be reduced.

[0048] In certain examples, it may be desirable that a minimum flow rate of fluid around the flow circuit is maintained to prevent any build-up of contaminants inside the printer. This is because is the flow rate drops below a predetermined flow rate, the lack of fluid moving in the flow circuit may prevent any contaminants being moved out of the printer. The flow rate may be, for example, a volumetric flow rate. For example, the flow rate may be measured in liters/minute of fluid moving around the flow circuit.

[0049] In certain examples, the climate control system 100 may comprise a flow rate indicator. The flow rate indicator may be located in the flow circuit. The flow rate indicator may be located in the flow passage 10. For example, the flow rate indicator may be located downstream of the contaminant separator 22 and located upstream of the fluid flow inducer 20. The flow rate indicator may produce an output commensurate with the flow rate of the fluid moving around the flow circuit. For example, where the flow rate indicator is located downstream of the contaminant separator 22, the flow rate indicator may produce an output commensurate with the flow rate of the treated fluid drawn from the contaminant separator 22. In certain examples, the flow rate indicator may be located in the inlet of the fluid flow inducer 20.

[0050] In certain examples, the climate control system 100 controller 24 may change the flow rate of the fluid moving around the flow circuit in response to the output from the flow rate indicator. In certain examples, the climate control system 100 controller 24 may cause an increase in the flow rate of the fluid moving around the flow circuit in response to a determination that the flow rate is below a predetermined flow rate. In certain examples, the climate control system 100 controller 24 may cause an increase in the flow rate of the treated fluid drawn from the contaminant separator 22 in response to a determination that the flow rate is below a predetermined flow rate.

[0051] In certain examples, the fluid flow inducer 20 may be controlled based on a determination of the flow rate of the fluid moving around the flow circuit. For example, the output of the fluid flow inducer 20 may be controlled based on a determination of the flow rate of the fluid moving around the flow circuit. In certain examples, if the flow rate of the fluid moving around the flow circuit is determined to be below a predetermined flow rate, the controller 24 may increase the output of the fluid flow inducer 20 until the flow rate of the fluid moving around the flow circuit is determined to be above the predetermined flow rate. For example, the controller may increase the output of the fluid flow inducer 20 if the flow rate of the treated fluid drawn from the contaminant separator 22 is below a predetermined flow rate.

[0052] In certain examples, a flow control valve may be provided in the flow circuit to control the flow rate around the flow circuit. In certain examples, the flow control valve may be provided in the flow passage 10. In certain examples, the flow control valve may be controlled by the controller 24. The flow control valve may be controlled based on a determination of the flow rate of the fluid moving around the flow circuit. Accordingly, if the flow rate of the fluid moving around the flow circuit is determined to be below a predetermined flow rate, the controller 24 may adjust the flow control valve to increase the flow rate of the fluid moving around the flow circuit until the flow rate is determined to be above the predetermined flow rate. For example, the controller may adjust the flow control valve to increase the flow rate if the flow rate of the treated fluid drawn from the contaminant separator 22 is below a predetermined flow rate.

[0053] With reference to Figure 1 , the operation of the climate control system 100 will now be described. During operation with a printer, the fluid flow inducer 20 of the climate control system 100 draws contaminated fluid in through the inlet 12 of the flow passage 10. The contaminated fluid is drawn into the inlet 12 from the contaminated fluid outlet of the printer. The contaminated fluid is drawn to the contaminant separator 22 where, during treatment, any contaminants in the contaminated fluid are separated out from the contaminated fluid as much as practically possible. The separation process produces a treated fluid. There may remain some residual contaminants in the treated fluid. The treated fluid is then drawn from the contaminant separator 22 by the fluid flow inducer and expelled through the outlet 14 of the flow passage 10 and into the treated fluid inlet of the printer. When the climate control system 100 is operating, the controller may control the fluid flow inducer 20 to control the pressure of the contaminated fluid in the inlet 12 of the flow passage 10.

[0054] The pressure of the contaminated fluid in the inlet 12 of the flow passage 10 controlled according to the following method. The method may comprise determining the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 of the climate control system 100. The method may comprise controlling the fluid flow inducer 20 to control the pressure of the contaminated fluid in the inlet 12 of the flow passage 10. Controlling the fluid flow inducer 20 may be in response to the determination of the pressure of the contaminated fluid in the inlet 12 of the flow passage 10.

[0055] In certain examples, the method may comprise controlling an output of the fluid flow inducer 20. In certain examples, the method may comprise reducing the output of the fluid flow inducer 20 to reduce the pressure of the contaminated fluid in the inlet 12 of the flow passage. Reducing of the output of the fluid flow inducer 20 may be in response to a determination that the pressure is above a predetermined pressure. In certain examples, the method may comprise controlling the fluid flow inducer 20 to control the pressure of the contaminated fluid in the inlet 12 of the flow passage 10 at approximately 50 Pa below atmospheric pressure.

[0056] In certain examples, the method may comprise determining a flow rate of the treated fluid drawn from the contaminant separator 22. The method may comprise, in response to a determination that the flow rate is below a predetermined flow rate, causing an increase in the flow rate of the treated fluid drawn from the contaminant separator. In certain examples, the method may comprise controlling the fluid flow inducer 20 to increase the flow rate of the treated fluid drawn from the contaminant separator 22. In certain examples, the method may comprise controlling an output of the fluid flow inducer 20 to increase the flow rate of the treated fluid drawn from the contaminant separator 22. The method may comprise, in response to a determination that the flow rate is below a predetermined flow rate, adjusting the flow control valve to increase the flow rate of the treated fluid drawn from the contaminant separator 22.

[0057] Further features, which may be present in certain examples of the printing system and of the climate control system, will now be described with respect to Figures 2, 3 and 4. Figure 2 schematically illustrates an example of a printing system 300 comprising a printer 200 and a climate control system 100 to operate with the printer 200. Figure 3 is a block diagram illustrating an example printing system 300 comprising a printer 200 and a climate control system 100 to operate with the printer 200. Figure 4 illustrates an example of a climate control system 100 assembled inside a cabinet 102.

[0058] With respect to Figure 3, the printing system 300 may comprise a flow circuit 302 in which fluid may be moved. The flow circuit 302 may pass through the printer 200, out from the printer 200 and into the climate control system 100, pass through the climate control system 100, out from the climate control system 100 and back into the printer 200.

[0059] As with the example described with respect to Figure 1 , the climate control system 100 comprises a fluid flow inducer, or fan 20 and a contaminant separator 22, both of which may be located in the flow circuit 302. When the climate control system 100 is in use in the printing system 200, the fan 20 may move fluid around the flow circuit 302 of the printing system and the contaminant separator 22 may treat the fluid moving in the flow circuit 302 by separating at least one contaminant out from the fluid.

[0060] In certain examples, the climate control system 100 may comprise the flow rate indicator described above, such as flow rate indicator 60 illustrated in Figure 3. The flow rate sensor 60 may be located in the flow circuit 302. The flow rate sensor 60 may be located in the flow passage 10, and located downstream of the contaminant separator 22, and located upstream of the fan 20. The flow rate indicator 60 may produce an output commensurate with the flow rate of the fluid moving around the flow circuit 302.

[0061] One example of a contaminant separator 22, as illustrated in Figures 2, 3 and 4, will now be described. In the example, the contaminant separator 22 may comprise a heat exchanger 26. The contaminated fluid, when it is drawn to the contaminant separator 22 by the fan, is passed through the heat exchanger 26. The heat exchanger 26 may cool the contaminated fluid to a predetermined dew point temperature. The predetermined dew point temperature may correspond to a desired level of one or more contaminants that will remain in the treated fluid that will be returned to the printer 200. For example, the predetermined dew point temperature may correspond to a trace level of one or more contaminants that will remain in the treated fluid that will be returned to the printer 200. Cooling the contaminated fluid to the predetermined dew point temperature may cause the one or more contaminants in the fluid to condense to a liquid condensate, which allows them to be separated out from the contaminated fluid to produce a treated fluid. For example, where the contaminated fluid contains VOC contaminants, the predetermined dew point temperature may correspond to a temperature sufficient to condense one or more VOC contaminant vapours. The liquid condensate containing the contaminants may be removed through a drain 30, for example, and then sent for disposal or recycling.

[0062] In certain examples, the contaminant separator 22 may also include a filter 28, for example a de-mister, located downstream of the heat exchanger 26. The filter 28 may act to aid removal of liquid droplets of one or more contaminants from the contaminated fluid as much as is practical. The filter 28 may be useful ensuring aerosol contaminants, such as liquid contaminant droplets are, separated out from the contaminated fluid to produce the treated fluid. The filter 28 is therefore also useful in preventing any residual condensate contaminant droplets from returning to the printer 200 and/or printing area. [0063] In certain examples, it may be desirable that the climate control system 100 conditions the treated fluid before it is returned to the printer and/or the printing area.

[0064] In certain examples, the climate control system 100 may comprise an economizer 32 to condition the treated fluid. The economizer 32 may be located in the flow passage. The economizer 32 may be an air-to-air heat exchanger. The air-to-air heat exchanger transfers heat from the contaminated fluid, drawn in through the inlet 12 of the flow passage 10, to the treated fluid, drawn from the contaminant separator 22. The fluid streams are not mixed. The fluid streams may be arranged substantially perpendicularly to one another. Thus, the air-to-air heat exchanger exchanges heat between the hotter fluid about to enter the contaminant separator 22 and the colder fluid leaving the contaminant separator 22. In this way, the contaminated fluid may be subjected to a measure of precooling before entering the condensing heat exchanger 26 and the treated fluid may be brought up to a desirable temperature before being returned to the printer. Thus, the economizer may save energy usage and allow the treated fluid to be conditioned to a desirable temperature before entering the printer.

[0065] In certain examples, the climate control system 100 may comprise a bypass 16. The bypass 16 allows some of the treated fluid to bypass the economizer 32 before returning to the flow passage 10.

[0066] In certain examples, the climate control system 100 the flow control valve described above, such as flow control valve 34 illustrated in Figure 2, may control the flow of fluid through the bypass 16. In certain examples, the flow control valve 34 may be located elsewhere in the flow passage 10. The flow control valve 34 may be, for example, a damper. The flow control valve 34 may be adjusted to be fully open, fully closed, or anywhere between fully open and fully closed. In this way, a variable portion of the treated fluid drawn from the contaminant separator 22 may pass through the bypass 16 and avoid heating by the economizer. The portion of the treated fluid drawn from the contaminant separator 22 that may pass through the bypass 16 may be varied by adjusting the flow control valve 34. [0067] In certain examples, the temperature of the treated air downstream of the economizer 32 may be monitored. The flow control valve 34 may be adjusted, based on the temperature of the treated air downstream of the economizer, to selectively vary the portion of the treated fluid passing through the bypass passage 16. In this way, the temperature of the treated air downstream of the economizer can be adjusted to a desired level. In certain examples, the controller 24 may control the adjustment of the flow control valve 34 based on the temperature of the treated air downstream of the economizer. In other examples, a thermostat or other suitable control mechanism may be operatively connected between the treated air downstream of the economizer and the flow control valve 34.

[0068] Thus, in certain examples, adjustment of the flow control valve 34 further allows the treated fluid to be conditioned to a desirable temperature for entering the printer.

[0001] In certain examples, the flow control valve 34 may be controlled based on a determination of the flow rate of the fluid moving around the flow circuit 302. The flow rate of the fluid moving around the flow circuit 302 may be determined from the output of the flow rate indicator 60, for example. If the flow rate of the fluid moving around the flow circuit 302 is determined to be below a predetermined flow rate, the controller 24 may open the flow control valve 34 to increase the flow rate of the fluid moving around the flow circuit 302, by allowing a larger portion of the fluid to pass through the bypass 16, until the flow rate is determined to be above the predetermined flow rate.

[0002] In certain examples, the climate control system 100 may comprise a humidifier 36. The humidifier 36 may be located in the flow passage 10. The humidifier 36 may be, for example, located downstream of the contaminant separator 22 and upstream of the economizer 32. The humidifier 36 may be positioned in the flow passage 10 such that treated fluid moves past or through the humidifier 36.

[0069] Since the contaminant separator 22 may operate to condense contaminants out of the moving fluid, the humidity level of the treated fluid may be determined to be undesirably low for ideal printing conditions. The humidifier 36 may therefore selectively add water to the treated fluid as needed to increase and/or maintain the humidity level of the treated fluid. As the humidifier 36 may be located upstream of the economizer 32, any excess water droplets from the humidifier 36 may be evaporated by the heat added from the economizer 32 to the treated fluid. In other examples, the humidifier 36 may be located further downstream from the economizer 32.

[0070] Figure 2 schematically illustrates how, in certain examples, the climate control system 100 may be arranged with the printer 200. The printer 200 may comprise a printing engine 202, on which printed images may be produced on a print target. The printer 200 may comprise one or more drying units 204 that aid the fixing of the printing substances used to form the image. One or more fans 206 may deliver fluid from the internal space of the printer 200 to the drying units 204.

[0071] In certain examples, the printer may comprise one or more suction units 208, which may draw fluid from the drying units 204 and deliver the fluid to the inlet 12 of the climate control system 100 through the contaminated fluid outlet of the printer.

[0072] In certain examples, the printer 200 may comprise a plenum 210. The treated fluid from the climate control system 100 may be delivered, from the treated fluid outlet 14, into the plenum 210 via the treated fluid inlet of the printer 200. The plenum 210 may comprise a perforated roof 212 through which the treated fluid may be evenly dispersed into the internal space of the printer 200.

[0073] The printer 200 may comprise a controller 224. The controller 224 may be in communicatively connected to the controller of the climate control system 100. It will be appreciated that the printer 200 controller 224 could carry out the functions of the climate control system 100 controller 24 as described above. For example, the printer 200 controller 224 may be communicatively connected to the climate control system 100 to control the functions of its components, for example, fan 20. [0074] With reference to Figures 2 and 3, the operation of the additional features of the climate control system 100 will now be described. During operation with a printer, the contaminated fluid drawn in through the inlet 12 of the flow passage 10 is passed through the economizer 32 where it is precooled. The contaminated fluid is drawn into the heat exchanger 26 of the contaminant separator 22. The contaminant fluid may be cooled to the dew point temperature of one or more contaminants in the contaminated fluid, which causes the contaminants to condense out of the contaminated fluid. The condensate may be drawn off through drain 30. The contaminated fluid may also be passed through filter 28 to remove any excess contaminant droplets, which may also be drawn off through drain 30. The now treated air may be humidified by humidifier 36 before being drawn through the economizer 32 to be warmed to a desired temperature suitable for entering the printer 200 and/or printing area. A portion of the treated fluid, the size of which can be varied, may be drawn through the bypass passage 16 so that it is not heated and then mixed with the treated fluid exiting the economizer 32 thereby allowing the temperature of the treated fluid to be adjustable. The treated fluid is drawn through the fan 20 and expelled through the outlet 14 of the flow passage 10 into the printer 200.

[0075] The example methods described above may be performed in the example printing system 300. For example, the methods described above may be performed in the example printing system 300 shown in Figures 2 and 3 and/or in the example climate control systems 100 shown in Figures 1 and 4. The printer 200 and climate control system 100 are illustrated in Figures 2 and 3 as separate, coupled, units. In certain examples, as discussed above, the printing system 300 may comprise a single unit comprising the printer 200 and climate control system 100.

[0076] The printing system may comprise at least one controller. For example, the printer 200 may comprise a controller 224 and the climate control system 100 may comprise the controller 24. In other examples, the printer may comprise a controller 224 that controls the climate control system 100. The controller(s) may comprise a computer. In other examples, the printing system may comprise one controller, which may be located in either the printer 200 or the climate control system 100.

[0077] The controller 224 of the printer 200 may cooperate with the controller 24 of the climate control system. The controller 24 may be communicatively connected with the printer 200 controller 202. The controller 24 and the printer 200 controller 202 may be communicatively connected with one another via communications interfaces. For example, the controller 24 may be electrically connected to the printer 200 controller 224 by way of communication cabling. However, it will be appreciated that a wireless communication protocol may be used.

[0078] The controller 24 of the climate control system 100 may be communicatively connected to other systems of the printer 200. For example, the controller 24 of the climate control system 100 may receive outputs from other systems of the printer 200. The controller 224 of the printer 200may be communicatively connected to other systems of the climate control system 100 and receive outputs from those systems.

[0079] In other examples, the functions of the controller 24 of the climate control system 100 may be performed by the controller 224 of the printer 200.

[0080] In other examples, either one of, or both of, the controllers 24, 224 may be remote from the printing system 300. For example, the controllers 24, 224 may be remotely connected to the printing system 300 over a network, which would allow the controllers 24, 224 and the other features of the printing system 300 to be located separately from each other, including the possibility of being separate by large distances. The connection may be a network connection.

[0081] The controller 24 may comprise a processor. The controller 224 may comprise a processor. The processor may carry out any of the processes or methods described herein or instruct they be carried out in the climate control system 100. The controller 24 may comprise a storage module. The storage module may comprise a non-transitory storage medium. The non-transitory machine-readable storage medium may be encoded with instructions executable by the processor. Some examples of non-transitory storage media are disks, thumb drives, memory cards and do not include propagated signals.

[0082] Any of the example processes or methods described herein may be encoded in machine readable form on the non-transitory storage medium. For example, the example processes or methods above may be in the form of a computer program comprising computer program code. For example, the non- transitory machine-readable storage medium may be encoded with instructions for performing all, or any of, the blocks described herein. For example, the processor may retrieve and execute the encoded instructions and perform any of the blocks described herein or instruct another device, such as the printer device, to perform any of the blocks described herein. The processor may retrieve and execute encoded instructions and perform additional blocks relating to other functions of the printing system.

[0083] The processor may be a parallel processor or a serial processor. The processor may execute the instructions may be carried out in any suitable order, or simultaneously.

[0084] In certain examples, the non-transitory machine-readable storage medium may be encoded with instructions 82, 84, which, when executed by a processor, control the processor to: determine a pressure of a contaminated fluid in an inlet of a flow passage of a climate control system, the contaminated fluid drawn, in use, by a fluid flow inducer located in the flow passage, from a contaminated fluid outlet of a printer into the inlet of the flow passage and to a contaminant separator located in the flow passage; and, control the fluid flow inducer to control the pressure of the contaminated fluid in the inlet of the flow passage based on the determined pressure.

[0085] In certain examples, the storage medium may be encoded with the instructions, which control the processor to: determine whether the pressure is above a predetermined pressure; and, in response to a determination that the pressure is above a predetermined pressure, reduce an output of the fluid flow inducer to reduce the pressure of the contaminated fluid in the inlet of the flow passage [0086] The contaminated fluid may be treated by the contaminant separator by separating out one or more contaminants from the contaminated fluid to produce a treated fluid. The treated fluid may be drawn from the contaminant separator and expelled, by the fluid flow inducer, through an outlet of the flow passage into a treated fluid inlet of the printer.

[0087] The non-transitory machine-readable storage medium may be encoded with the other instructions relating to the functioning of the printing system.

[0088] It will be appreciated that the example blocks may be implemented at various locations throughout the printing system, for instance in the controller 24 or in the printing system 300. In addition, in some examples, the blocks may be implemented in the printer 200 and/or in the climate control system 100. As described above, the climate control system 100 and the printer 200 may be combined into a single unit and the blocks may be implemented in one location.

[0089] It will be appreciated that the example blocks may be implemented at various locations across a network. For example, a remote computer may store encoded instructions for performing an example of the calibration process described above. A local or terminal computer may access the remote computer and access the encoded instructions. It will be appreciated that the example blocks may be implemented by a dedicated circuit, for example a DSP or a programmable logic array.

[0090] The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is to be understood that any feature described in relation to any one example may be used alone, or in combination with other features described, and may also be used in combination with any features of any other of the examples, or any combination of any other of the examples.

Claims

CLAIMS What is claimed is:

1 . A climate control system to operate with a printer, the system comprising:

a flow passage comprising an inlet and an outlet, wherein the inlet is to fluidly communicate with a contaminated fluid outlet of the printer, and the outlet is to fluidly communicate with a treated fluid inlet of the printer;

a contaminant separator located in the flow passage, the contaminant separator to produce a treated fluid by separating out one or more contaminants from a contaminated fluid;

a fluid flow inducer located in the fluid flow passage, the fan to draw the contaminated fluid from the printer through the inlet and to the contaminant separator, and to draw the treated fluid from the contaminant separator and expel the treated fluid into the printer through the outlet; and

a controller to control the fluid flow inducer based on a determination of a pressure of the contaminated fluid in the inlet of the flow passage.

2. A climate control system according to claim 1 comprising a pressure sensor located in the inlet, wherein the determination of the pressure of the contaminated fluid in the inlet of the flow passage is based on an output from the pressure sensor.

3. A climate control system according to claim 1 comprising a flow rate indicator located in the flow passage.

4. A climate control system according to claim 3, wherein the controller is to control the fluid flow inducer based on a determination of a flow rate of the treated fluid drawn from the contaminant separator, and wherein the determination of the flow rate of the treated fluid is based on an output from the flow rate indicator.

5. A climate control system according to claim 3, wherein the controller is to adjust a flow control valve based on a determination of a flow rate of the treated fluid drawn from the contaminant separator, and wherein the determination of the flow rate of the treated fluid is based on an output from the flow rate indicator.

6. A climate control system according to claim 5, wherein the climate control system comprises an economizer located in the flow passage, and wherein the economizer is to exchange heat from the contaminated fluid to the treated fluid.

7. A climate control system according to claim 6, wherein the climate control system comprises a bypass to bypass the economizer and wherein the flow control valve is to control the flow of the treated fluid through the bypass.

8. A climate control system according to claim 1 wherein the contaminant separator comprises a heat exchanger and a filter.

9. A method comprising:

determining a pressure of a contaminated fluid in an inlet of a flow passage of a climate control system, the contaminated fluid drawn, by a fluid flow inducer located in the flow passage, from a contaminated fluid outlet of a printer into the inlet and to a contaminant separator located in the flow passage, the contaminated fluid treated by the contaminant separator by separating out one or more contaminants from the contaminated fluid to produce a treated fluid, the treated fluid drawn from the contaminant separator and expelled, by the fluid flow inducer, through an outlet of the flow passage into a treated fluid inlet of the printer; and

controlling the fluid flow inducer to control the pressure of the contaminated fluid in the inlet of the flow passage based on the determined pressure.

10. A method according to claim 9, wherein the method comprises:

in response to a determination that the pressure is above a predetermined pressure, reducing the output of the fluid flow inducer to reduce the pressure of the contaminated fluid in the inlet of the flow passage.

11. A method according to claim 9 wherein the method comprises:

determining a flow rate of the treated fluid drawn from the contaminant separator; and

in response to a determination that the flow rate is below a predetermined flow rate, causing an increase in the flow rate of the treated fluid drawn from the contaminant separator.

12. A method according to claim 11 , wherein increasing the flow rate is caused by adjusting a flow control valve to located in the flow passage.

13. A non-transitory machine-readable storage medium comprising instructions executable by a processor, the storage medium comprising:

instructions to determine a pressure of a contaminated fluid in an inlet of a flow passage of a climate control system, the contaminated fluid drawn, in use, by a fluid flow inducer located in the flow passage, from a contaminated fluid outlet of a printer into the inlet of the flow passage and to a contaminant separator located in the flow passage;

instructions to determine whether the pressure is above a predetermined pressure; and

instructions to, in response to a determination that the pressure is above the predetermined pressure, reduce an output of the fluid flow inducer to reduce the pressure of the contaminated fluid in the inlet of the flow passage.

14. A printing system comprising:

a printer; a climate control system to operate with the printer;

a flow circuit passing through the printer, out from the printer and into the climate control system, through the climate control system, and out from the climate control system and back into the printer; wherein the climate control system comprises:

a contaminant separator located in the flow circuit, the contaminant separator to separate out at least one contaminant from fluid moving in the flow circuit;

a fan located in the flow circuit, the fan to move the fluid from the printer to the contaminant separator, and from the contaminant separator into the printer; and

wherein the printing system comprises a pressure sensor located, in the flow circuit, upstream of the contaminant separator and downstream of the fan.

15. A printing system according to claim 14 comprising a controller to control the fan based on an output from the pressure sensor.