Manifold heat insulation

Additionally, space is required for manifolding and heat insulation while space is also required at the top and bottom of the module so as to gain maximal profit of the available membrane surface area. Fig. 2.14. A module vessel consisting of an insulated double wall has the advantage of minimization of expensiveheat- and oxygen-resistant stainless steel, used for relatively thin inner walls, and therefore reduction of the total costs of the module. Accommodation of the pressure inside the module is reached by a thick cold external wall that can be manufactured from cheap steel. 

A thermoplastic injection mold in which the mold that contains the runner system has its own heating elements to keep the molding material in a plastic state ready for injection into the cavities, from which the manifold is insulated. 

The manifold is pressed against the nozzles by ceramic pads in a steel body, which improves heat insulation. The manifold is held in place with the aid of hardened plates set in the clamping plate, which prevents damage (gashing) of the soft plate during thermal expansion of the manifold. 

Heat insulation for a manifold is aimed at limiting heat losses, and also at limiting unwanted heat flows into the mould cavity. The following means of achieving a consistent and uniform temperature distribution are used ... 

In comparison to the surrounding components, the manifold is insulated using an all-around air gap. Experience shows that the gap width should be between 8 and 10 mm because this is the optimum concerning the minimum amount of heat loss. Shiny surfaces can minimize the radiation losses of the hot manifold. A nickel coating is recommended to reduce radiation. The amount of radiation heat loss is less than 10%. Measures reducing contact heat promise greater effectiveness. 

The sample of desorbed tritide is placed inside a quartz tube that is connected to a gas-handling manifold by a TorrSeal . A quartz sleeve with Silicon Carbide (SiC) in the annular space is placed around the end of the quartz tube, surrounding the sample with microwave susceptor. The quartz tube and susceptor sleeve are thermally insulated from the rest of the microwave cavity. An internal thermocouple measures the temperature of the sample and provides the temperature signal for process control of the desired temperature. A shine block (alumina foam), attached to the thermocouple, blocks radiant heating of the TorrSeal and the upper area of the quartz tube and manifold. An IR pyrometer is used as a secondary measure of the temperature of the susceptor, and therefore of the sample. A stainless steel shield reflects microwaves from the quartz tube not in the susceptor sleeve, eliminating the production of a plasma at low pressure in the quartz tube. 

Figure 1. The MHHP modular sorber diagram 1 - tubular case of the hydride module 2 -corrugated heat-conducting insert 3 - hydrogen ceramic collector-filter 4 - metal hydride 5 - tip of a metal hydride bed 6 - hydrogen manifold 7 - spacer plate 8 - heat exchanger shroud 9 - union 10 - flange-cover of a heat exchanger. Heat exchanger thermal insulation is not shown conditionally.

Figure 2. The MHHP monoblock sorber diagram 1 - case of a sorber 2 - heat exchanging tube 3 - heat-conducting edges 4 - metal hydride 5 - tube with metal hydride bed 6 -ceramic hydrogen collector-filter 7-hydrogen manifold 8 - casing of a heat exchanger 9 -union. Thermal insulation of a heat exchanger is not shown conditionally.

The constmction of a gas manifold incorporating four mass flow controllers allowed the mixing of water saturated air with dry air to produce test streams of gas with accurate RH. Measured amounts of hydrogen were then added to the test stream. An environmental test chamber was also constructed from an insulated cooler. A heating element on the test chamber and a proportional temperature controller allowed control of the gas temperature and thus the thin film temperature to within 0. PC. 

To accomplish this, a) Place controllable and adequate heat sources at proper locations of the die heads and manifolds, b) Cover and insulate any large areas of exposed bare metal surfaces around die heads and manifolds. This is to prevent the heat loss through free convection, and to improve response time when heat is required. It also prevents the surface temperature of any localized area inside the flow channels to fall below the temperature of melt or worse yet, below melting point. In either case, melt next to these areas will slow down, stick, or freeze onto those surfaces. When changing color, they will be the sources of streaking. 

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